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* [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:05 David Cohen
  2013-10-29 18:05   ` David Cohen
                   ` (5 more replies)
  0 siblings, 6 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:05 UTC (permalink / raw)
  To: broonie; +Cc: ning.li, linux-kernel, linux-spi, Fei Yang, David Cohen

From: Fei Yang <fei.yang@intel.com>

This patch adds driver for ssp spi interface on Intel Mid platform.

Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Fei Yang <fei.yang@intel.com>
Reviewed-by: Ning Li <ning.li@intel.com>
---
 drivers/spi/Kconfig                   |   12 +
 drivers/spi/Makefile                  |    1 +
 drivers/spi/spi-intel-mid-ssp.c       | 1506 +++++++++++++++++++++++++++++++++
 include/linux/spi/intel_mid_ssp_spi.h |  330 ++++++++
 4 files changed, 1849 insertions(+)
 create mode 100644 drivers/spi/spi-intel-mid-ssp.c
 create mode 100644 include/linux/spi/intel_mid_ssp_spi.h

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index b9c53cc..e211829 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -211,6 +211,18 @@ config SPI_IMX
 	  This enables using the Freescale i.MX SPI controllers in master
 	  mode.
 
+config SPI_INTEL_MID_SSP
+	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
+	depends on X86_INTEL_MID && SPI_MASTER && INTEL_MID_DMAC
+	help
+	  Select Y or M to build the unified SSP SPI slave controller driver
+	  for the Intel MID platforms (Medfield, Clovertrail and Merrifield),
+	  primarily used to implement a SPI host controller driver over a SSP
+	  host controller.
+
+	  If you choose to build this driver as module it will be called
+	  spi-intel-mid-ssp.ko
+
 config SPI_LM70_LLP
 	tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)"
 	depends on PARPORT
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index ab8d864..60c8a1e 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_SPI_FSL_ESPI)		+= spi-fsl-espi.o
 obj-$(CONFIG_SPI_FSL_SPI)		+= spi-fsl-spi.o
 obj-$(CONFIG_SPI_GPIO)			+= spi-gpio.o
 obj-$(CONFIG_SPI_IMX)			+= spi-imx.o
+obj-$(CONFIG_SPI_INTEL_MID_SSP)		+= spi-intel-mid-ssp.o
 obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
 obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
 obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
new file mode 100644
index 0000000..b3b9fe8
--- /dev/null
+++ b/drivers/spi/spi-intel-mid-ssp.c
@@ -0,0 +1,1506 @@
+/*
+ * spi-intel-mid-ssp.c
+ * This driver supports Bulverde SSP core used on Intel MID platforms
+ * It supports SSP of Moorestown & Medfield platforms and handles clock
+ * slave & master modes.
+ *
+ * Copyright (c) 2013, Intel Corporation.
+ * Contacts: Ning Li <ning.li@intel.com>
+ *	     David Cohen <david.a.cohen@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*
+ * Note:
+ *
+ * Supports DMA and non-interrupt polled transfers.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/intel_mid_dma.h>
+#include <linux/pm_qos.h>
+#include <linux/pm_runtime.h>
+#include <linux/completion.h>
+#include <asm/intel-mid.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/intel_mid_ssp_spi.h>
+
+#define DRIVER_NAME "intel_mid_ssp_spi_unified"
+
+static int ssp_timing_wr;
+
+#ifdef DUMP_RX
+static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
+{
+	int tlen1 = (len < sz ? len : sz);
+	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
+	unsigned char *p;
+	static char msg[MAX_SPI_TRANSFER_SIZE];
+
+	memset(msg, '\0', sizeof(msg));
+	p = buf;
+	while (p < buf + tlen1)
+		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
+
+	if (tlen2 > 0) {
+		sprintf(msg, "%s .....", msg);
+		p = (buf+len) - tlen2;
+		while (p < buf + len)
+			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
+	}
+
+	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
+		   len-tlen2, len - 1, msg);
+}
+#endif
+
+static inline u8 ssp_cfg_get_mode(u8 ssp_cfg)
+{
+	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
+		return (ssp_cfg) & 0x03;
+	else
+		return (ssp_cfg) & 0x07;
+}
+
+static inline u8 ssp_cfg_get_spi_bus_nb(u8 ssp_cfg)
+{
+	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
+		return ((ssp_cfg) >> 2) & 0x07;
+	else
+		return ((ssp_cfg) >> 3) & 0x07;
+}
+
+static inline u8 ssp_cfg_is_spi_slave(u8 ssp_cfg)
+{
+	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
+		return (ssp_cfg) & 0x20;
+	else
+		return (ssp_cfg) & 0x40;
+}
+
+static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
+{
+	u32 sssr;
+	sssr = read_SSSR(sspc->ioaddr);
+	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
+		return 0;
+	else
+		return 1;
+}
+
+static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
+{
+	return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
+}
+
+static inline void disable_interface(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+}
+
+static inline void disable_triggers(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	write_SSCR1(read_SSCR1(reg) & ~sspc->cr1_sig, reg);
+}
+
+
+static void flush(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	u32 i = 0;
+
+	/* If the transmit fifo is not empty, reset the interface. */
+	if (!is_tx_fifo_empty(sspc)) {
+		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
+		disable_interface(sspc);
+		return;
+	}
+
+	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
+	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
+		read_SSDR(reg);
+		i++;
+	}
+	WARN(i > 0, "%d words flush occured\n", i);
+
+	return;
+}
+
+static int null_writer(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	u8 n_bytes = sspc->n_bytes;
+
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (sspc->tx == sspc->tx_end))
+		return 0;
+
+	write_SSDR(0, reg);
+	sspc->tx += n_bytes;
+
+	return 1;
+}
+
+static int null_reader(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	u8 n_bytes = sspc->n_bytes;
+
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (sspc->rx < sspc->rx_end)) {
+		read_SSDR(reg);
+		sspc->rx += n_bytes;
+	}
+
+	return sspc->rx == sspc->rx_end;
+}
+
+static int u8_writer(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (sspc->tx == sspc->tx_end))
+		return 0;
+
+	write_SSDR(*(u8 *)(sspc->tx), reg);
+	++sspc->tx;
+
+	return 1;
+}
+
+static int u8_reader(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	while ((read_SSSR(reg) & SSSR_RNE)
+		&& (sspc->rx < sspc->rx_end)) {
+		*(u8 *)(sspc->rx) = read_SSDR(reg);
+		++sspc->rx;
+	}
+
+	return sspc->rx == sspc->rx_end;
+}
+
+static int u16_writer(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (sspc->tx == sspc->tx_end))
+		return 0;
+
+	write_SSDR(*(u16 *)(sspc->tx), reg);
+	sspc->tx += 2;
+
+	return 1;
+}
+
+static int u16_reader(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
+		*(u16 *)(sspc->rx) = read_SSDR(reg);
+		sspc->rx += 2;
+	}
+
+	return sspc->rx == sspc->rx_end;
+}
+
+static int u32_writer(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
+		|| (sspc->tx == sspc->tx_end))
+		return 0;
+
+	write_SSDR(*(u32 *)(sspc->tx), reg);
+	sspc->tx += 4;
+
+	return 1;
+}
+
+static int u32_reader(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
+		*(u32 *)(sspc->rx) = read_SSDR(reg);
+		sspc->rx += 4;
+	}
+
+	return sspc->rx == sspc->rx_end;
+}
+
+static bool chan_filter(struct dma_chan *chan, void *param)
+{
+	struct ssp_drv_context *sspc = param;
+
+	if (sspc->dmac1 && chan->device->dev == &sspc->dmac1->dev)
+		return true;
+
+	return false;
+}
+
+/**
+ * unmap_dma_buffers() - Unmap the DMA buffers used during the last transfer.
+ * @sspc:	Pointer to the private driver context
+ */
+static void unmap_dma_buffers(struct ssp_drv_context *sspc)
+{
+	struct device *dev = &sspc->pdev->dev;
+
+	if (!sspc->dma_mapped)
+		return;
+	dma_unmap_single(dev, sspc->rx_dma, sspc->len, PCI_DMA_FROMDEVICE);
+	dma_unmap_single(dev, sspc->tx_dma, sspc->len, PCI_DMA_TODEVICE);
+	sspc->dma_mapped = 0;
+}
+
+/**
+ * ssp_spi_dma_done() - End of DMA transfer callback
+ * @arg:	Pointer to the data provided at callback registration
+ *
+ * This function is set as callback for both RX and TX DMA transfers. The
+ * RX or TX 'done' flag is set acording to the direction of the ended
+ * transfer. Then, if both RX and TX flags are set, it means that the
+ * transfer job is completed.
+ */
+static void ssp_spi_dma_done(void *arg)
+{
+	struct callback_param *cb_param = (struct callback_param *)arg;
+	struct ssp_drv_context *sspc = cb_param->drv_context;
+	struct device *dev = &sspc->pdev->dev;
+	void *reg = sspc->ioaddr;
+
+	if (cb_param->direction == TX_DIRECTION)
+		sspc->txdma_done = 1;
+	else
+		sspc->rxdma_done = 1;
+
+	dev_dbg(dev, "DMA callback for direction %d [RX done:%d] [TX done:%d]\n",
+		cb_param->direction, sspc->rxdma_done,
+		sspc->txdma_done);
+
+	if (sspc->txdma_done && sspc->rxdma_done) {
+		/* Clear Status Register */
+		write_SSSR(sspc->clear_sr, reg);
+		dev_dbg(dev, "DMA done\n");
+		/* Disable Triggers to DMA or to CPU*/
+		disable_triggers(sspc);
+		unmap_dma_buffers(sspc);
+
+		queue_work(sspc->dma_wq, &sspc->complete_work);
+	}
+}
+
+/**
+ * ssp_spi_dma_init() - Initialize DMA
+ * @sspc:	Pointer to the private driver context
+ *
+ * This function is called at driver setup phase to allocate DMA
+ * ressources.
+ */
+static void ssp_spi_dma_init(struct ssp_drv_context *sspc)
+{
+	struct intel_mid_dma_slave *rxs, *txs;
+	struct dma_slave_config *ds;
+	dma_cap_mask_t mask;
+	struct device *dev = &sspc->pdev->dev;
+	unsigned int device_id;
+
+	/* Configure RX channel parameters */
+	rxs = &sspc->dmas_rx;
+	ds = &rxs->dma_slave;
+
+	ds->direction = DMA_FROM_DEVICE;
+	rxs->hs_mode = LNW_DMA_HW_HS;
+	rxs->cfg_mode = LNW_DMA_PER_TO_MEM;
+	ds->dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	ds->src_addr_width = sspc->n_bytes;
+
+	/* Use a DMA burst according to the FIFO thresholds */
+	if (sspc->rx_fifo_threshold == 8) {
+		ds->src_maxburst = 8;
+		ds->dst_maxburst = 8;
+	} else if (sspc->rx_fifo_threshold == 4) {
+		ds->src_maxburst = 4;
+		ds->dst_maxburst = 4;
+	} else {
+		ds->src_maxburst = 1;
+		ds->dst_maxburst = 1;
+	}
+
+	/* Configure TX channel parameters */
+	txs = &sspc->dmas_tx;
+	ds = &txs->dma_slave;
+
+	ds->direction = DMA_TO_DEVICE;
+	txs->hs_mode = LNW_DMA_HW_HS;
+	txs->cfg_mode = LNW_DMA_MEM_TO_PER;
+	ds->src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	ds->dst_addr_width = sspc->n_bytes;
+
+	/* Use a DMA burst according to the FIFO thresholds */
+	if (sspc->rx_fifo_threshold == 8) {
+		ds->src_maxburst = 8;
+		ds->dst_maxburst = 8;
+	} else if (sspc->rx_fifo_threshold == 4) {
+		ds->src_maxburst = 4;
+		ds->dst_maxburst = 4;
+	} else {
+		ds->src_maxburst = 1;
+		ds->dst_maxburst = 1;
+	}
+
+	/* Nothing more to do if already initialized */
+	if (sspc->dma_initialized)
+		return;
+
+	/* Use DMAC1 */
+	if (sspc->quirks & QUIRKS_PLATFORM_MRST)
+		device_id = PCI_MRST_DMAC1_ID;
+	else
+		device_id = PCI_MDFL_DMAC1_ID;
+
+	sspc->dmac1 = pci_get_device(PCI_VENDOR_ID_INTEL, device_id, NULL);
+	if (!sspc->dmac1) {
+		dev_err(dev, "Can't find DMAC1");
+		return;
+	}
+
+	if (sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY) {
+		sspc->virt_addr_sram_rx = ioremap_nocache(SRAM_BASE_ADDR,
+				2 * MAX_SPI_TRANSFER_SIZE);
+		if (sspc->virt_addr_sram_rx)
+			sspc->virt_addr_sram_tx = sspc->virt_addr_sram_rx +
+							MAX_SPI_TRANSFER_SIZE;
+		else
+			dev_err(dev, "Virt_addr_sram_rx is null\n");
+	}
+
+	/* 1. Allocate rx channel */
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	sspc->rxchan = dma_request_channel(mask, chan_filter, sspc);
+	if (!sspc->rxchan)
+		goto err_exit;
+
+	sspc->rxchan->private = rxs;
+
+	/* 2. Allocate tx channel */
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+
+	sspc->txchan = dma_request_channel(mask, chan_filter, sspc);
+	if (!sspc->txchan)
+		goto free_rxchan;
+	else
+		sspc->txchan->private = txs;
+
+	/* set the dma done bit to 1 */
+	sspc->txdma_done = 1;
+	sspc->rxdma_done = 1;
+
+	sspc->tx_param.drv_context  = sspc;
+	sspc->tx_param.direction = TX_DIRECTION;
+	sspc->rx_param.drv_context  = sspc;
+	sspc->rx_param.direction = RX_DIRECTION;
+
+	sspc->dma_initialized = 1;
+	return;
+
+free_rxchan:
+	dma_release_channel(sspc->rxchan);
+err_exit:
+	dev_err(dev, "Error : DMA Channel Not available\n");
+
+	if (sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY)
+		iounmap(sspc->virt_addr_sram_rx);
+
+	pci_dev_put(sspc->dmac1);
+	return;
+}
+
+/**
+ * ssp_spi_dma_exit() - Release DMA ressources
+ * @sspc:	Pointer to the private driver context
+ */
+static void ssp_spi_dma_exit(struct ssp_drv_context *sspc)
+{
+	dma_release_channel(sspc->txchan);
+	dma_release_channel(sspc->rxchan);
+
+	if (sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY)
+		iounmap(sspc->virt_addr_sram_rx);
+
+	pci_dev_put(sspc->dmac1);
+}
+
+/**
+ * dma_transfer() - Initiate a DMA transfer
+ * @sspc:	Pointer to the private driver context
+ */
+static void dma_transfer(struct ssp_drv_context *sspc)
+{
+	dma_addr_t ssdr_addr;
+	struct dma_async_tx_descriptor *txdesc = NULL, *rxdesc = NULL;
+	struct dma_chan *txchan, *rxchan;
+	enum dma_ctrl_flags flag;
+	struct device *dev = &sspc->pdev->dev;
+
+	/* get Data Read/Write address */
+	ssdr_addr = (dma_addr_t)(sspc->paddr + 0x10);
+
+	if (sspc->tx_dma)
+		sspc->txdma_done = 0;
+
+	if (sspc->rx_dma)
+		sspc->rxdma_done = 0;
+
+	/* 2. prepare the RX dma transfer */
+	txchan = sspc->txchan;
+	rxchan = sspc->rxchan;
+
+	flag = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
+
+	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
+		/* Since the DMA is configured to do 32bits access */
+		/* to/from the DDR, the DMA transfer size must be  */
+		/* a multiple of 4 bytes                           */
+		sspc->len_dma_rx = sspc->len & ~(4 - 1);
+		sspc->len_dma_tx = sspc->len_dma_rx;
+
+		/* In Rx direction, TRAIL Bytes are handled by memcpy */
+		if (sspc->rx_dma &&
+			(sspc->len_dma_rx >
+				sspc->rx_fifo_threshold * sspc->n_bytes))
+			sspc->len_dma_rx = TRUNCATE(sspc->len_dma_rx,
+				sspc->rx_fifo_threshold * sspc->n_bytes);
+		else if (!sspc->rx_dma)
+			dev_err(dev, "ERROR : rx_dma is null\r\n");
+	} else {
+		/* TRAIL Bytes are handled by DMA */
+		if (sspc->rx_dma) {
+			sspc->len_dma_rx = sspc->len;
+			sspc->len_dma_tx = sspc->len;
+		} else
+			dev_err(dev, "ERROR : sspc->rx_dma is null!\n");
+	}
+
+	rxdesc = rxchan->device->device_prep_dma_memcpy
+		(rxchan,			/* DMA Channel */
+		sspc->rx_dma,			/* DAR */
+		ssdr_addr,			/* SAR */
+		sspc->len_dma_rx,		/* Data Length */
+		flag);					/* Flag */
+
+	if (rxdesc) {
+		rxdesc->callback = ssp_spi_dma_done;
+		rxdesc->callback_param = &sspc->rx_param;
+	} else {
+		dev_dbg(dev, "rxdesc is null! (len_dma_rx:%d)\n",
+			sspc->len_dma_rx);
+		sspc->rxdma_done = 1;
+	}
+
+	/* 3. prepare the TX dma transfer */
+	if (sspc->tx_dma) {
+		txdesc = txchan->device->device_prep_dma_memcpy
+			(txchan,			/* DMA Channel */
+			ssdr_addr,			/* DAR */
+			sspc->tx_dma,			/* SAR */
+			sspc->len_dma_tx,		/* Data Length */
+			flag);				/* Flag */
+		if (txdesc) {
+			txdesc->callback = ssp_spi_dma_done;
+			txdesc->callback_param = &sspc->tx_param;
+		} else {
+			dev_dbg(dev, "txdesc is null! (len_dma_tx:%d)\n",
+				sspc->len_dma_tx);
+			sspc->txdma_done = 1;
+		}
+	} else {
+		dev_err(dev, "ERROR : sspc->tx_dma is null!\n");
+		return;
+	}
+
+	dev_info(dev, "DMA transfer len:%d len_dma_tx:%d len_dma_rx:%d\n",
+		sspc->len, sspc->len_dma_tx, sspc->len_dma_rx);
+
+	if (rxdesc || txdesc) {
+		if (rxdesc) {
+			dev_dbg(dev, "Firing DMA RX channel\n");
+			rxdesc->tx_submit(rxdesc);
+		}
+		if (txdesc) {
+			dev_dbg(dev, "Firing DMA TX channel\n");
+			txdesc->tx_submit(txdesc);
+		}
+	} else {
+		struct callback_param cb_param;
+		cb_param.drv_context = sspc;
+		dev_dbg(dev, "Bypassing DMA transfer\n");
+		ssp_spi_dma_done(&cb_param);
+	}
+}
+
+/**
+ * map_dma_buffers() - Map DMA buffer before a transfer
+ * @sspc:	Pointer to the private drivzer context
+ */
+static int map_dma_buffers(struct ssp_drv_context *sspc)
+{
+	struct device *dev = &sspc->pdev->dev;
+
+	if (unlikely(sspc->dma_mapped)) {
+		dev_err(dev, "ERROR : DMA buffers already mapped\n");
+		return 0;
+	}
+	if (unlikely(sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY)) {
+		/* Copy sspc->tx into sram_tx */
+		memcpy_toio(sspc->virt_addr_sram_tx, sspc->tx, sspc->len);
+#ifdef DUMP_RX
+		dump_trailer(&sspc->pdev->dev, sspc->tx, sspc->len, 16);
+#endif
+		sspc->rx_dma = SRAM_RX_ADDR;
+		sspc->tx_dma = SRAM_TX_ADDR;
+	} else {
+		/* no QUIRKS_SRAM_ADDITIONAL_CPY */
+		if (unlikely(sspc->dma_mapped))
+			return 1;
+
+		sspc->tx_dma = dma_map_single(dev, sspc->tx, sspc->len,
+						PCI_DMA_TODEVICE);
+		if (unlikely(dma_mapping_error(dev, sspc->tx_dma))) {
+			dev_err(dev, "ERROR : tx dma mapping failed\n");
+			return 0;
+		}
+
+		sspc->rx_dma = dma_map_single(dev, sspc->rx, sspc->len,
+						PCI_DMA_FROMDEVICE);
+		if (unlikely(dma_mapping_error(dev, sspc->rx_dma))) {
+			dma_unmap_single(dev, sspc->tx_dma,
+				sspc->len, DMA_TO_DEVICE);
+			dev_err(dev, "ERROR : rx dma mapping failed\n");
+			return 0;
+		}
+	}
+	return 1;
+}
+
+/**
+ * drain_trail() - Handle trailing bytes of a transfer
+ * @sspc:	Pointer to the private driver context
+ *
+ * This function handles the trailing bytes of a transfer for the case
+ * they are not handled by the DMA.
+ */
+static void drain_trail(struct ssp_drv_context *sspc)
+{
+	struct device *dev = &sspc->pdev->dev;
+	void *reg = sspc->ioaddr;
+
+	if (sspc->len != sspc->len_dma_rx) {
+		dev_dbg(dev, "Handling trailing bytes. SSSR:%08x\n",
+			read_SSSR(reg));
+		sspc->rx += sspc->len_dma_rx;
+		sspc->tx += sspc->len_dma_tx;
+
+		while ((sspc->tx != sspc->tx_end) ||
+			(sspc->rx != sspc->rx_end)) {
+			sspc->read(sspc);
+			sspc->write(sspc);
+		}
+	}
+}
+
+/**
+ * sram_to_ddr_cpy() - Copy data from Langwell SDRAM to DDR
+ * @sspc:	Pointer to the private driver context
+ */
+static void sram_to_ddr_cpy(struct ssp_drv_context *sspc)
+{
+	u32 length = sspc->len;
+
+	if ((sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)
+		&& (sspc->len > sspc->rx_fifo_threshold * sspc->n_bytes))
+		length = TRUNCATE(sspc->len,
+			sspc->rx_fifo_threshold * sspc->n_bytes);
+
+	memcpy_fromio(sspc->rx, sspc->virt_addr_sram_rx, length);
+}
+
+static void int_transfer_complete(struct ssp_drv_context *sspc)
+{
+	void *reg = sspc->ioaddr;
+	struct spi_message *msg;
+	struct device *dev = &sspc->pdev->dev;
+
+	if (unlikely(sspc->quirks & QUIRKS_USE_PM_QOS))
+		pm_qos_update_request(&sspc->pm_qos_req,
+					PM_QOS_DEFAULT_VALUE);
+
+	if (unlikely(sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY))
+		sram_to_ddr_cpy(sspc);
+
+	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL))
+		drain_trail(sspc);
+	else
+		/* Stop getting Time Outs */
+		write_SSTO(0, reg);
+
+	sspc->cur_msg->status = 0;
+	sspc->cur_msg->actual_length = sspc->len;
+
+#ifdef DUMP_RX
+	dump_trailer(dev, sspc->rx, sspc->len, 16);
+#endif
+
+	dev_dbg(dev, "End of transfer. SSSR:%08X\n", read_SSSR(reg));
+	msg = sspc->cur_msg;
+	if (likely(msg->complete))
+		msg->complete(msg->context);
+	complete(&sspc->msg_done);
+}
+
+static void int_transfer_complete_work(struct work_struct *work)
+{
+	struct ssp_drv_context *sspc = container_of(work,
+				struct ssp_drv_context, complete_work);
+
+	int_transfer_complete(sspc);
+}
+
+static void poll_transfer_complete(struct ssp_drv_context *sspc)
+{
+	struct spi_message *msg;
+
+	/* Update total byte transfered return count actual bytes read */
+	sspc->cur_msg->actual_length += sspc->len - (sspc->rx_end - sspc->rx);
+
+	sspc->cur_msg->status = 0;
+	msg = sspc->cur_msg;
+	if (likely(msg->complete))
+		msg->complete(msg->context);
+	complete(&sspc->msg_done);
+}
+
+/**
+ * ssp_int() - Interrupt handler
+ * @irq
+ * @dev_id
+ *
+ * The SSP interrupt is not used for transfer which are handled by
+ * DMA or polling: only under/over run are catched to detect
+ * broken transfers.
+ */
+static irqreturn_t ssp_int(int irq, void *dev_id)
+{
+	struct ssp_drv_context *sspc = dev_id;
+	void *reg = sspc->ioaddr;
+	struct device *dev = &sspc->pdev->dev;
+	u32 status = read_SSSR(reg);
+
+	/* It should never be our interrupt since SSP will */
+	/* only trigs interrupt for under/over run.        */
+	if (likely(!(status & sspc->mask_sr)))
+		return IRQ_NONE;
+
+	if (status & SSSR_ROR || status & SSSR_TUR) {
+		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
+		WARN_ON(1);
+		if (status & SSSR_ROR)
+			dev_err(dev, "we have Overrun\n");
+		if (status & SSSR_TUR)
+			dev_err(dev, "we have Underrun\n");
+	}
+
+	/* We can fall here when not using DMA mode */
+	if (!sspc->cur_msg) {
+		disable_interface(sspc);
+		disable_triggers(sspc);
+	}
+	/* clear status register */
+	write_SSSR(sspc->clear_sr, reg);
+	return IRQ_HANDLED;
+}
+
+static void poll_transfer(unsigned long data)
+{
+	struct ssp_drv_context *sspc = (void *)data;
+
+	if (sspc->tx) {
+		while (sspc->tx != sspc->tx_end) {
+			if (ssp_timing_wr) {
+				int timeout = 100;
+				/* It is used as debug UART on Tangier. Since
+				   baud rate = 115200, it needs at least 312us
+				   for one word transferring. Becuase of silicon
+				   issue, it MUST check SFIFOL here instead of
+				   TNF. It is the workaround for A0 stepping*/
+				while (--timeout &&
+					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
+					udelay(10);
+			}
+			sspc->write(sspc);
+			sspc->read(sspc);
+		}
+	}
+
+	while (!sspc->read(sspc))
+		cpu_relax();
+
+	poll_transfer_complete(sspc);
+}
+
+/**
+ * start_bitbanging() - Clock synchronization by bit banging
+ * @sspc:	Pointer to private driver context
+ *
+ * This clock synchronization will be removed as soon as it is
+ * handled by the SCU.
+ */
+static void start_bitbanging(struct ssp_drv_context *sspc)
+{
+	u32 sssr;
+	u32 count = 0;
+	u32 cr0;
+	void *i2c_reg = sspc->I2C_ioaddr;
+	struct device *dev = &sspc->pdev->dev;
+	void *reg = sspc->ioaddr;
+	struct chip_data *chip = spi_get_ctldata(sspc->cur_msg->spi);
+	cr0 = chip->cr0;
+
+	dev_warn(dev, "In %s : Starting bit banging\n",
+		__func__);
+	if (read_SSSR(reg) & SSP_NOT_SYNC)
+		dev_warn(dev, "SSP clock desynchronized.\n");
+	if (!(read_SSCR0(reg) & SSCR0_SSE))
+		dev_warn(dev, "in SSCR0, SSP disabled.\n");
+
+	dev_dbg(dev, "SSP not ready, start CLK sync\n");
+
+	write_SSCR0(cr0 & ~SSCR0_SSE, reg);
+	write_SSPSP(0x02010007, reg);
+
+	write_SSTO(chip->timeout, reg);
+	write_SSCR0(cr0, reg);
+
+	/*
+	*  This routine uses the DFx block to override the SSP inputs
+	*  and outputs allowing us to bit bang SSPSCLK. On Langwell,
+	*  we have to generate the clock to clear busy.
+	*/
+	write_I2CDATA(0x3, i2c_reg);
+	udelay(I2C_ACCESS_USDELAY);
+	write_I2CCTRL(0x01070034, i2c_reg);
+	udelay(I2C_ACCESS_USDELAY);
+	write_I2CDATA(0x00000099, i2c_reg);
+	udelay(I2C_ACCESS_USDELAY);
+	write_I2CCTRL(0x01070038, i2c_reg);
+	udelay(I2C_ACCESS_USDELAY);
+	sssr = read_SSSR(reg);
+
+	/* Bit bang the clock until CSS clears */
+	while ((sssr & 0x400000) && (count < MAX_BITBANGING_LOOP)) {
+		write_I2CDATA(0x2, i2c_reg);
+		udelay(I2C_ACCESS_USDELAY);
+		write_I2CCTRL(0x01070034, i2c_reg);
+		udelay(I2C_ACCESS_USDELAY);
+		write_I2CDATA(0x3, i2c_reg);
+		udelay(I2C_ACCESS_USDELAY);
+		write_I2CCTRL(0x01070034, i2c_reg);
+		udelay(I2C_ACCESS_USDELAY);
+		sssr = read_SSSR(reg);
+		count++;
+	}
+	if (count >= MAX_BITBANGING_LOOP)
+		dev_err(dev, "ERROR in %s : infinite loop on bit banging. Aborting\n",
+								__func__);
+
+	dev_dbg(dev, "---Bit bang count=%d\n", count);
+
+	write_I2CDATA(0x0, i2c_reg);
+	udelay(I2C_ACCESS_USDELAY);
+	write_I2CCTRL(0x01070038, i2c_reg);
+}
+
+static unsigned int ssp_get_clk_div(int speed)
+{
+	return max(100000000 / speed, 4) - 1;
+}
+
+/**
+ * transfer() - Start a SPI transfer
+ * @spi:	Pointer to the spi_device struct
+ * @msg:	Pointer to the spi_message struct
+ */
+static int transfer(struct spi_device *spi, struct spi_message *msg)
+{
+	struct ssp_drv_context *sspc = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	msg->actual_length = 0;
+	msg->status = -EINPROGRESS;
+	spin_lock_irqsave(&sspc->lock, flags);
+	list_add_tail(&msg->queue, &sspc->queue);
+	if (!sspc->suspended)
+		queue_work(sspc->workqueue, &sspc->pump_messages);
+	spin_unlock_irqrestore(&sspc->lock, flags);
+
+	return 0;
+}
+
+static int handle_message(struct ssp_drv_context *sspc)
+{
+	struct chip_data *chip = NULL;
+	struct spi_transfer *transfer = NULL;
+	void *reg = sspc->ioaddr;
+	u32 cr1;
+	struct device *dev = &sspc->pdev->dev;
+	struct spi_message *msg = sspc->cur_msg;
+
+	chip = spi_get_ctldata(msg->spi);
+
+	/* We handle only one transfer message since the protocol module has to
+	   control the out of band signaling. */
+	transfer = list_entry(msg->transfers.next, struct spi_transfer,
+					transfer_list);
+
+	/* Check transfer length */
+	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
+		(transfer->len == 0))) {
+		dev_warn(dev, "transfer length null or greater than %d\n",
+			MAX_SPI_TRANSFER_SIZE);
+		dev_warn(dev, "length = %d\n", transfer->len);
+		msg->status = -EINVAL;
+
+		if (msg->complete)
+			msg->complete(msg->context);
+		complete(&sspc->msg_done);
+		return 0;
+	}
+
+	/* Flush any remaining data (in case of failed previous transfer) */
+	flush(sspc);
+
+	sspc->tx  = (void *)transfer->tx_buf;
+	sspc->rx  = (void *)transfer->rx_buf;
+	sspc->len = transfer->len;
+	sspc->write = chip->write;
+	sspc->read = chip->read;
+
+	if (likely(chip->dma_enabled)) {
+		sspc->dma_mapped = map_dma_buffers(sspc);
+		if (unlikely(!sspc->dma_mapped))
+			return 0;
+	} else {
+		sspc->write = sspc->tx ? chip->write : null_writer;
+		sspc->read  = sspc->rx ? chip->read : null_reader;
+	}
+	sspc->tx_end = sspc->tx + transfer->len;
+	sspc->rx_end = sspc->rx + transfer->len;
+	write_SSSR(sspc->clear_sr, reg);
+
+	/* setup the CR1 control register */
+	cr1 = chip->cr1 | sspc->cr1_sig;
+
+	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
+		/* in case of len smaller than burst size, adjust the RX     */
+		/* threshold. All other cases will use the default threshold */
+		/* value. The RX fifo threshold must be aligned with the DMA */
+		/* RX transfer size, which may be limited to a multiple of 4 */
+		/* bytes due to 32bits DDR access.                           */
+		if  (sspc->len / sspc->n_bytes <= sspc->rx_fifo_threshold) {
+			u32 rx_fifo_threshold;
+
+			rx_fifo_threshold = (sspc->len & ~(4 - 1)) /
+						sspc->n_bytes;
+			cr1 &= ~(SSCR1_RFT);
+			cr1 |= SSCR1_RxTresh(rx_fifo_threshold) & SSCR1_RFT;
+		} else
+			write_SSTO(chip->timeout, reg);
+	}
+
+	dev_dbg(dev, "transfer len:%d  n_bytes:%d  cr0:%x  cr1:%x",
+		sspc->len, sspc->n_bytes, chip->cr0, cr1);
+
+	/* first set CR1 */
+	write_SSCR1(cr1, reg);
+
+	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
+		write_SSFS((1 << chip->chip_select), reg);
+
+	/* Do bitbanging only if SSP not-enabled or not-synchronized */
+	if (unlikely(((read_SSSR(reg) & SSP_NOT_SYNC) ||
+		(!(read_SSCR0(reg) & SSCR0_SSE))) &&
+		(sspc->quirks & QUIRKS_BIT_BANGING))) {
+			start_bitbanging(sspc);
+	} else {
+		/* (re)start the SSP */
+		if (ssp_timing_wr) {
+			chip->cr0 = 0x00c0000f;
+			write_SSCR0(chip->cr0, reg);
+			chip->cr0 = 0x00c12c0f;
+			write_SSCR0(chip->cr0, reg);
+			chip->cr0 = 0x00c12c8f;
+			write_SSCR0(chip->cr0, reg);
+		} else {
+			write_SSCR0(chip->cr0, reg);
+		}
+	}
+
+	if (likely(chip->dma_enabled)) {
+		if (unlikely(sspc->quirks & QUIRKS_USE_PM_QOS))
+			pm_qos_update_request(&sspc->pm_qos_req,
+				MIN_EXIT_LATENCY);
+		dma_transfer(sspc);
+	} else
+		tasklet_schedule(&sspc->poll_transfer);
+
+	return 0;
+}
+
+static void pump_messages(struct work_struct *work)
+{
+	struct ssp_drv_context *sspc =
+		container_of(work, struct ssp_drv_context, pump_messages);
+	struct device *dev = &sspc->pdev->dev;
+	unsigned long flags;
+	struct spi_message *msg;
+
+	pm_runtime_get_sync(dev);
+	spin_lock_irqsave(&sspc->lock, flags);
+	while (!list_empty(&sspc->queue)) {
+		if (sspc->suspended)
+			break;
+		msg = list_entry(sspc->queue.next, struct spi_message, queue);
+		list_del_init(&msg->queue);
+		sspc->cur_msg = msg;
+		spin_unlock_irqrestore(&sspc->lock, flags);
+		INIT_COMPLETION(sspc->msg_done);
+		handle_message(sspc);
+		wait_for_completion(&sspc->msg_done);
+		spin_lock_irqsave(&sspc->lock, flags);
+		sspc->cur_msg = NULL;
+	}
+	spin_unlock_irqrestore(&sspc->lock, flags);
+	pm_runtime_put(dev);
+}
+
+/**
+ * setup() - Driver setup procedure
+ * @spi:	Pointeur to the spi_device struct
+ */
+static int setup(struct spi_device *spi)
+{
+	struct intel_mid_ssp_spi_chip *chip_info = NULL;
+	struct chip_data *chip;
+	struct ssp_drv_context *sspc =
+		spi_master_get_devdata(spi->master);
+	u32 tx_fifo_threshold;
+	u32 burst_size;
+	u32 clk_div;
+
+	if (!spi->bits_per_word)
+		spi->bits_per_word = DFLT_BITS_PER_WORD;
+
+	if ((spi->bits_per_word < MIN_BITS_PER_WORD
+		|| spi->bits_per_word > MAX_BITS_PER_WORD))
+		return -EINVAL;
+
+	chip = spi_get_ctldata(spi);
+	if (!chip) {
+		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+		if (!chip) {
+			dev_err(&spi->dev,
+			"failed setup: can't allocate chip data\n");
+			return -ENOMEM;
+		}
+	}
+	chip->cr0 = SSCR0_Motorola | SSCR0_DataSize(spi->bits_per_word > 16 ?
+		spi->bits_per_word - 16 : spi->bits_per_word)
+			| SSCR0_SSE
+			| (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
+
+	/* protocol drivers may change the chip settings, so...  */
+	/* if chip_info exists, use it                           */
+	chip_info = spi->controller_data;
+
+	/* chip_info isn't always needed */
+	chip->cr1 = 0;
+	if (chip_info) {
+		burst_size = chip_info->burst_size;
+		if (burst_size > IMSS_FIFO_BURST_8)
+			burst_size = DFLT_FIFO_BURST_SIZE;
+
+		chip->timeout = chip_info->timeout;
+
+		if (chip_info->enable_loopback)
+			chip->cr1 |= SSCR1_LBM;
+
+		chip->dma_enabled = chip_info->dma_enabled;
+
+	} else {
+		/* if no chip_info provided by protocol driver, */
+		/* set default values                           */
+		dev_info(&spi->dev, "setting default chip values\n");
+
+		burst_size = DFLT_FIFO_BURST_SIZE;
+		chip->dma_enabled = 1;
+		if (sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)
+			chip->timeout = 0;
+		else
+			chip->timeout = DFLT_TIMEOUT_VAL;
+	}
+	/* Set FIFO thresholds according to burst_size */
+	if (burst_size == IMSS_FIFO_BURST_8)
+		sspc->rx_fifo_threshold = 8;
+	else if (burst_size == IMSS_FIFO_BURST_4)
+		sspc->rx_fifo_threshold = 4;
+	else
+		sspc->rx_fifo_threshold = 1;
+	tx_fifo_threshold = SPI_FIFO_SIZE - sspc->rx_fifo_threshold;
+	chip->cr1 |= (SSCR1_RxTresh(sspc->rx_fifo_threshold) &
+		SSCR1_RFT) | (SSCR1_TxTresh(tx_fifo_threshold) & SSCR1_TFT);
+
+	sspc->dma_mapped = 0;
+
+	/* setting phase and polarity. spi->mode comes from boardinfo */
+	if ((spi->mode & SPI_CPHA) != 0)
+		chip->cr1 |= SSCR1_SPH;
+	if ((spi->mode & SPI_CPOL) != 0)
+		chip->cr1 |= SSCR1_SPO;
+
+	if (sspc->quirks & QUIRKS_SPI_SLAVE_CLOCK_MODE)
+		/* set slave mode */
+		chip->cr1 |= SSCR1_SCLKDIR | SSCR1_SFRMDIR;
+	chip->cr1 |= SSCR1_SCFR;        /* clock is not free running */
+
+	dev_dbg(&spi->dev, "%d bits/word, mode %d\n",
+		spi->bits_per_word, spi->mode & 0x3);
+	if (spi->bits_per_word <= 8) {
+		chip->n_bytes = 1;
+		chip->read = u8_reader;
+		chip->write = u8_writer;
+	} else if (spi->bits_per_word <= 16) {
+		chip->n_bytes = 2;
+		chip->read = u16_reader;
+		chip->write = u16_writer;
+	} else if (spi->bits_per_word <= 32) {
+		if (!ssp_timing_wr)
+			chip->cr0 |= SSCR0_EDSS;
+		chip->n_bytes = 4;
+		chip->read = u32_reader;
+		chip->write = u32_writer;
+	} else {
+		dev_err(&spi->dev, "invalid wordsize\n");
+		return -EINVAL;
+	}
+
+	if ((sspc->quirks & QUIRKS_SPI_SLAVE_CLOCK_MODE) == 0) {
+		chip->speed_hz = spi->max_speed_hz;
+		clk_div = ssp_get_clk_div(chip->speed_hz);
+		if (!ssp_timing_wr)
+			chip->cr0 |= clk_div << 8;
+	}
+	chip->bits_per_word = spi->bits_per_word;
+	chip->chip_select = spi->chip_select;
+
+	spi_set_ctldata(spi, chip);
+
+	/* setup of sspc members that will not change across transfers */
+	sspc->n_bytes = chip->n_bytes;
+
+	if (chip->dma_enabled) {
+		ssp_spi_dma_init(sspc);
+		sspc->cr1_sig = SSCR1_TSRE | SSCR1_RSRE;
+		sspc->mask_sr = SSSR_ROR | SSSR_TUR;
+		if (sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)
+			sspc->cr1_sig |= SSCR1_TRAIL;
+	} else {
+		sspc->cr1_sig = SSCR1_RIE | SSCR1_TIE | SSCR1_TINTE;
+		sspc->mask_sr = SSSR_RFS | SSSR_TFS |
+				 SSSR_ROR | SSSR_TUR | SSSR_TINT;
+	}
+	sspc->clear_sr = SSSR_TUR | SSSR_ROR | SSSR_TINT;
+
+	return 0;
+}
+
+/**
+ * cleanup() - Driver cleanup procedure
+ * @spi:	Pointer to the spi_device struct
+ */
+static void cleanup(struct spi_device *spi)
+{
+	struct chip_data *chip = spi_get_ctldata(spi);
+	struct ssp_drv_context *sspc =
+		spi_master_get_devdata(spi->master);
+
+	if (sspc->dma_initialized)
+		ssp_spi_dma_exit(sspc);
+
+	/* Remove the PM_QOS request */
+	if (sspc->quirks & QUIRKS_USE_PM_QOS)
+		pm_qos_remove_request(&sspc->pm_qos_req);
+
+	kfree(chip);
+	spi_set_ctldata(spi, NULL);
+}
+
+/**
+ * ssp_spi_probe() - Driver probe procedure
+ * @pdev:	Pointer to the pci_dev struct
+ * @ent:	Pointer to the pci_device_id struct
+ */
+static int ssp_spi_probe(struct pci_dev *pdev,
+	const struct pci_device_id *ent)
+{
+	struct device *dev = &pdev->dev;
+	struct spi_master *master;
+	struct ssp_drv_context *sspc = 0;
+	int status;
+	u32 iolen = 0;
+	u8 ssp_cfg;
+	int pos;
+	void __iomem *syscfg_ioaddr;
+	unsigned long syscfg;
+
+	/* Check if the SSP we are probed for has been allocated */
+	/* to operate as SPI. This information is retreived from */
+	/* the field adid of the Vendor-Specific PCI capability  */
+	/* which is used as a configuration register.            */
+	pos = pci_find_capability(pdev, PCI_CAP_ID_VNDR);
+	if (pos > 0) {
+		pci_read_config_byte(pdev,
+			pos + VNDR_CAPABILITY_ADID_OFFSET,
+			&ssp_cfg);
+	} else {
+		dev_info(dev, "No Vendor Specific PCI capability\n");
+		goto err_abort_probe;
+	}
+
+	if (ssp_cfg_get_mode(ssp_cfg) != SSP_CFG_SPI_MODE_ID) {
+		dev_info(dev, "Unsupported SSP mode (%02xh)\n", ssp_cfg);
+		goto err_abort_probe;
+	}
+
+	dev_info(dev, "found PCI SSP controller (ID: %04xh:%04xh cfg: %02xh)\n",
+		pdev->vendor, pdev->device, ssp_cfg);
+
+	status = pci_enable_device(pdev);
+	if (status)
+		return status;
+
+	/* Allocate Slave with space for sspc and null dma buffer */
+	master = spi_alloc_master(dev, sizeof(struct ssp_drv_context));
+
+	if (!master) {
+		dev_err(dev, "cannot alloc spi_slave\n");
+		status = -ENOMEM;
+		goto err_free_0;
+	}
+
+	sspc = spi_master_get_devdata(master);
+	sspc->master = master;
+
+	sspc->pdev = pdev;
+	sspc->quirks = ent->driver_data;
+
+	/* Set platform & configuration quirks */
+	if (sspc->quirks & QUIRKS_PLATFORM_MRST) {
+		/* Apply bit banging workarround on MRST */
+		sspc->quirks |= QUIRKS_BIT_BANGING;
+		/* MRST slave mode workarrounds */
+		if (ssp_cfg_is_spi_slave(ssp_cfg))
+			sspc->quirks |= QUIRKS_USE_PM_QOS |
+					QUIRKS_SRAM_ADDITIONAL_CPY;
+	}
+	sspc->quirks |= QUIRKS_DMA_USE_NO_TRAIL;
+	if (ssp_cfg_is_spi_slave(ssp_cfg))
+		sspc->quirks |= QUIRKS_SPI_SLAVE_CLOCK_MODE;
+
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+	master->bus_num = ssp_cfg_get_spi_bus_nb(ssp_cfg);
+	master->num_chipselect = 4;
+	master->cleanup = cleanup;
+	master->setup = setup;
+	master->transfer = transfer;
+	sspc->dma_wq = create_workqueue("spi-intel-mid-ssp");
+	INIT_WORK(&sspc->complete_work, int_transfer_complete_work);
+
+	sspc->dma_initialized = 0;
+	sspc->suspended = 0;
+	sspc->cur_msg = NULL;
+
+	/* get basic io resource and map it */
+	sspc->paddr = pci_resource_start(pdev, 0);
+	iolen = pci_resource_len(pdev, 0);
+
+	status = pci_request_region(pdev, 0, dev_name(&pdev->dev));
+	if (status)
+		goto err_free_1;
+
+	sspc->ioaddr = ioremap_nocache(sspc->paddr, iolen);
+	if (!sspc->ioaddr) {
+		status = -ENOMEM;
+		goto err_free_2;
+	}
+	dev_dbg(dev, "paddr = : %08lx", sspc->paddr);
+	dev_dbg(dev, "ioaddr = : %p\n", sspc->ioaddr);
+	dev_dbg(dev, "attaching to IRQ: %04x\n", pdev->irq);
+	dev_dbg(dev, "quirks = : %08lx\n", sspc->quirks);
+
+	if (sspc->quirks & QUIRKS_BIT_BANGING) {
+		/* Bit banging on the clock is done through */
+		/* DFT which is available through I2C.      */
+		/* get base address of I2C_Serbus registers */
+		sspc->I2C_paddr = 0xff12b000;
+		sspc->I2C_ioaddr = ioremap_nocache(sspc->I2C_paddr, 0x10);
+		if (!sspc->I2C_ioaddr) {
+			status = -ENOMEM;
+			goto err_free_3;
+		}
+	}
+
+	/* Attach to IRQ */
+	sspc->irq = pdev->irq;
+	status = request_irq(sspc->irq, ssp_int, IRQF_SHARED,
+		"spi-intel-mid-ssp", sspc);
+
+	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
+		ssp_timing_wr = 1;
+
+	if (status < 0) {
+		dev_err(&pdev->dev, "can not get IRQ\n");
+		goto err_free_4;
+	}
+
+	if (sspc->quirks & QUIRKS_PLATFORM_MDFL) {
+		/* get base address of DMA selector. */
+		syscfg = sspc->paddr - SYSCFG;
+		syscfg_ioaddr = ioremap_nocache(syscfg, 0x10);
+		if (!syscfg_ioaddr) {
+			status = -ENOMEM;
+			goto err_free_5;
+		}
+		iowrite32(ioread32(syscfg_ioaddr) | 2, syscfg_ioaddr);
+	}
+
+	INIT_LIST_HEAD(&sspc->queue);
+	init_completion(&sspc->msg_done);
+	spin_lock_init(&sspc->lock);
+	tasklet_init(&sspc->poll_transfer, poll_transfer, (unsigned long)sspc);
+	INIT_WORK(&sspc->pump_messages, pump_messages);
+	sspc->workqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
+
+	/* Register with the SPI framework */
+	dev_info(dev, "register with SPI framework (bus spi%d)\n",
+			master->bus_num);
+
+	status = spi_register_master(master);
+	if (status) {
+		dev_err(dev, "problem registering spi\n");
+		goto err_free_5;
+	}
+
+	pci_set_drvdata(pdev, sspc);
+
+	/* Create the PM_QOS request */
+	if (sspc->quirks & QUIRKS_USE_PM_QOS)
+		pm_qos_add_request(&sspc->pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
+				   PM_QOS_DEFAULT_VALUE);
+
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_allow(&pdev->dev);
+
+	return status;
+
+err_free_5:
+	free_irq(sspc->irq, sspc);
+err_free_4:
+	iounmap(sspc->I2C_ioaddr);
+err_free_3:
+	iounmap(sspc->ioaddr);
+err_free_2:
+	pci_release_region(pdev, 0);
+err_free_1:
+	spi_master_put(master);
+err_free_0:
+	pci_disable_device(pdev);
+
+	return status;
+err_abort_probe:
+	dev_info(dev, "Abort probe for SSP %04xh:%04xh\n",
+		 pdev->vendor, pdev->device);
+	return -ENODEV;
+}
+
+/**
+ * ssp_spi_remove() - driver remove procedure
+ * @pdev:	Pointer to the pci_dev struct
+ */
+static void ssp_spi_remove(struct pci_dev *pdev)
+{
+	struct ssp_drv_context *sspc = pci_get_drvdata(pdev);
+
+	if (!sspc)
+		return;
+
+	pm_runtime_forbid(&pdev->dev);
+	pm_runtime_get_noresume(&pdev->dev);
+	/* Release IRQ */
+	free_irq(sspc->irq, sspc);
+
+	iounmap(sspc->ioaddr);
+	if (sspc->quirks & QUIRKS_BIT_BANGING)
+		iounmap(sspc->I2C_ioaddr);
+
+	/* disconnect from the SPI framework */
+	spi_unregister_master(sspc->master);
+
+	pci_set_drvdata(pdev, NULL);
+	pci_release_region(pdev, 0);
+	pci_disable_device(pdev);
+
+	return;
+}
+
+static int ssp_spi_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ssp_drv_context *sspc = pci_get_drvdata(pdev);
+	unsigned long flags;
+	int loop = 26;
+
+	spin_lock_irqsave(&sspc->lock, flags);
+	sspc->suspended = 1;
+	/*
+	 * If there is one msg being handled, wait 500ms at most,
+	 * if still not done, return busy
+	 */
+	while (sspc->cur_msg && --loop) {
+		spin_unlock_irqrestore(&sspc->lock, flags);
+		msleep(20);
+		spin_lock_irqsave(&sspc->lock, flags);
+		if (!loop)
+			sspc->suspended = 0;
+	}
+	spin_unlock_irqrestore(&sspc->lock, flags);
+
+	if (loop)
+		return 0;
+	else
+		return -EBUSY;
+}
+
+static int ssp_spi_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct ssp_drv_context *sspc = pci_get_drvdata(pdev);
+
+	spin_lock(&sspc->lock);
+	sspc->suspended = 0;
+	if (!list_empty(&sspc->queue))
+		queue_work(sspc->workqueue, &sspc->pump_messages);
+	spin_unlock(&sspc->lock);
+	return 0;
+}
+
+static int ssp_spi_runtime_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int ssp_spi_runtime_resume(struct device *dev)
+{
+	return 0;
+}
+
+static int ssp_spi_runtime_idle(struct device *dev)
+{
+	int err;
+
+	dev_dbg(dev, "runtime idle called\n");
+	if (system_state == SYSTEM_BOOTING)
+		/* if SSP SPI UART is set as default console and earlyprintk
+		 * is enabled, it cannot shutdown SSP controller during booting.
+		 */
+		err = pm_schedule_suspend(dev, 30000);
+	else
+		err = pm_schedule_suspend(dev, 500);
+
+	return err;
+}
+
+static DEFINE_PCI_DEVICE_TABLE(pci_ids) = {
+	/* MRST SSP0 */
+	{ PCI_VDEVICE(INTEL, 0x0815), QUIRKS_PLATFORM_MRST},
+	/* MDFL SSP0 */
+	{ PCI_VDEVICE(INTEL, 0x0832), QUIRKS_PLATFORM_MDFL},
+	/* MDFL SSP1 */
+	{ PCI_VDEVICE(INTEL, 0x0825), QUIRKS_PLATFORM_MDFL},
+	/* MDFL SSP3 */
+	{ PCI_VDEVICE(INTEL, 0x0816), QUIRKS_PLATFORM_MDFL},
+	/* MRFL SSP5 */
+	{ PCI_VDEVICE(INTEL, 0x1194), 0},
+	{ 0 },
+};
+
+static const struct dev_pm_ops ssp_spi_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ssp_spi_suspend, ssp_spi_resume)
+	SET_RUNTIME_PM_OPS(ssp_spi_runtime_suspend, ssp_spi_runtime_resume,
+			   ssp_spi_runtime_idle)
+};
+
+static struct pci_driver ssp_spi_driver = {
+	.name =		DRIVER_NAME,
+	.id_table =	pci_ids,
+	.probe =	ssp_spi_probe,
+	.remove =	ssp_spi_remove,
+	.driver =	{
+		.pm	= &ssp_spi_pm_ops,
+	},
+};
+
+static int __init ssp_spi_init(void)
+{
+	return pci_register_driver(&ssp_spi_driver);
+}
+
+late_initcall(ssp_spi_init);
+
+static void __exit ssp_spi_exit(void)
+{
+	pci_unregister_driver(&ssp_spi_driver);
+}
+
+module_exit(ssp_spi_exit);
+
+MODULE_AUTHOR("Ken Mills");
+MODULE_DESCRIPTION("Bulverde SSP core SPI contoller");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/spi/intel_mid_ssp_spi.h b/include/linux/spi/intel_mid_ssp_spi.h
new file mode 100644
index 0000000..a3bb973
--- /dev/null
+++ b/include/linux/spi/intel_mid_ssp_spi.h
@@ -0,0 +1,330 @@
+/*
+ *  Copyright (C) Intel 2013
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ */
+#ifndef INTEL_MID_SSP_SPI_H_
+#define INTEL_MID_SSP_SPI_H_
+
+#include <linux/completion.h>
+#include <linux/intel_mid_dma.h>
+#include <linux/interrupt.h>
+#include <linux/pm_qos.h>
+#include <linux/spi/spi.h>
+
+#define PCI_MRST_DMAC1_ID	0x0814
+#define PCI_MDFL_DMAC1_ID	0x0827
+
+#define SSP_NOT_SYNC		0x400000
+#define MAX_SPI_TRANSFER_SIZE	8192
+#define MAX_BITBANGING_LOOP	10000
+#define SPI_FIFO_SIZE		16
+
+/* PM QoS define */
+#define MIN_EXIT_LATENCY	20
+
+/* SSP assignement configuration from PCI config */
+
+#define SSP_CFG_SPI_MODE_ID		1
+/* adid field offset is 6 inside the vendor specific capability */
+#define VNDR_CAPABILITY_ADID_OFFSET	6
+
+/* Driver's quirk flags */
+/* This workarround bufferizes data in the audio fabric SDRAM from  */
+/* where the DMA transfers will operate. Should be enabled only for */
+/* SPI slave mode.                                                  */
+#define QUIRKS_SRAM_ADDITIONAL_CPY	1
+/* If set the trailing bytes won't be handled by the DMA.           */
+/* Trailing byte feature not fully available.                       */
+#define QUIRKS_DMA_USE_NO_TRAIL		2
+/* If set, the driver will use PM_QOS to reduce the latency         */
+/* introduced by the deeper C-states which may produce over/under   */
+/* run issues. Must be used in slave mode. In master mode, the      */
+/* latency is not critical, but setting this workarround  may       */
+/* improve the SPI throughput.                                      */
+#define QUIRKS_USE_PM_QOS		4
+/* This quirks is set on Moorestown                                 */
+#define QUIRKS_PLATFORM_MRST		8
+/* This quirks is set on Medfield                                   */
+#define QUIRKS_PLATFORM_MDFL		16
+/* If set, the driver will apply the bitbanging workarround needed  */
+/* to enable defective Langwell stepping A SSP. The defective SSP   */
+/* can be enabled only once, and should never be disabled.          */
+#define QUIRKS_BIT_BANGING		32
+/* If set, SPI is in slave clock mode                               */
+#define QUIRKS_SPI_SLAVE_CLOCK_MODE	64
+
+/* Uncomment to get RX and TX short dumps after each transfer */
+/* #define DUMP_RX 1 */
+#define MAX_TRAILING_BYTE_RETRY	16
+#define MAX_TRAILING_BYTE_LOOP	100
+#define DELAY_TO_GET_A_WORD	3
+#define DFLT_TIMEOUT_VAL	500
+
+#define DEFINE_SSP_REG(reg, off) \
+static inline u32 read_##reg(void *p) { return __raw_readl(p + (off)); } \
+static inline void write_##reg(u32 v, void *p) { __raw_writel(v, p + (off)); }
+
+#define RX_DIRECTION 0
+#define TX_DIRECTION 1
+
+#define I2C_ACCESS_USDELAY 10
+
+#define DFLT_BITS_PER_WORD	16
+#define MIN_BITS_PER_WORD	4
+#define MAX_BITS_PER_WORD	32
+#define DFLT_FIFO_BURST_SIZE	IMSS_FIFO_BURST_8
+
+#define TRUNCATE(x, a) ((x) & ~((a)-1))
+
+DEFINE_SSP_REG(SSCR0, 0x00)
+DEFINE_SSP_REG(SSCR1, 0x04)
+DEFINE_SSP_REG(SSSR, 0x08)
+DEFINE_SSP_REG(SSITR, 0x0c)
+DEFINE_SSP_REG(SSDR, 0x10)
+DEFINE_SSP_REG(SSTO, 0x28)
+DEFINE_SSP_REG(SSPSP, 0x2c)
+DEFINE_SSP_REG(SSFS, 0x44)
+DEFINE_SSP_REG(SFIFOL, 0x68)
+
+DEFINE_SSP_REG(I2CCTRL, 0x00);
+DEFINE_SSP_REG(I2CDATA, 0x04);
+
+DEFINE_SSP_REG(GPLR1, 0x04);
+DEFINE_SSP_REG(GPDR1, 0x0c);
+DEFINE_SSP_REG(GPSR1, 0x14);
+DEFINE_SSP_REG(GPCR1, 0x1c);
+DEFINE_SSP_REG(GAFR1_U, 0x44);
+
+#define SYSCFG  0x20bc0
+
+#define SRAM_BASE_ADDR 0xfffdc000
+#define SRAM_RX_ADDR   SRAM_BASE_ADDR
+#define SRAM_TX_ADDR  (SRAM_BASE_ADDR + MAX_SPI_TRANSFER_SIZE)
+
+#define SSCR0_DSS   (0x0000000f)     /* Data Size Select (mask) */
+#define SSCR0_DataSize(x)  ((x) - 1)    /* Data Size Select [4..16] */
+#define SSCR0_FRF   (0x00000030)     /* FRame Format (mask) */
+#define SSCR0_Motorola        (0x0 << 4)         /* Motorola's SPI mode */
+#define SSCR0_ECS   (1 << 6) /* External clock select */
+#define SSCR0_SSE   (1 << 7) /* Synchronous Serial Port Enable */
+
+#define SSCR0_SCR   (0x000fff00)      /* Serial Clock Rate (mask) */
+#define SSCR0_SerClkDiv(x) (((x) - 1) << 8) /* Divisor [1..4096] */
+#define SSCR0_EDSS  (1 << 20)           /* Extended data size select */
+#define SSCR0_NCS   (1 << 21)           /* Network clock select */
+#define SSCR0_RIM    (1 << 22)           /* Receive FIFO overrrun int mask */
+#define SSCR0_TUM   (1 << 23)           /* Transmit FIFO underrun int mask */
+#define SSCR0_FRDC (0x07000000)     /* Frame rate divider control (mask) */
+#define SSCR0_SlotsPerFrm(x) (((x) - 1) << 24) /* Time slots per frame */
+#define SSCR0_ADC   (1 << 30)           /* Audio clock select */
+#define SSCR0_MOD  (1 << 31)           /* Mode (normal or network) */
+
+#define SSCR1_RIE    (1 << 0) /* Receive FIFO Interrupt Enable */
+#define SSCR1_TIE     (1 << 1) /* Transmit FIFO Interrupt Enable */
+#define SSCR1_LBM   (1 << 2) /* Loop-Back Mode */
+#define SSCR1_SPO   (1 << 3) /* SSPSCLK polarity setting */
+#define SSCR1_SPH   (1 << 4) /* Motorola SPI SSPSCLK phase setting */
+#define SSCR1_MWDS           (1 << 5) /* Microwire Transmit Data Size */
+#define SSCR1_TFT    (0x000003c0)     /* Transmit FIFO Threshold (mask) */
+#define SSCR1_TxTresh(x) (((x) - 1) << 6) /* level [1..16] */
+#define SSCR1_RFT    (0x00003c00)     /* Receive FIFO Threshold (mask) */
+#define SSCR1_RxTresh(x) (((x) - 1) << 10) /* level [1..16] */
+
+#define SSSR_TNF		(1 << 2)	/* Tx FIFO Not Full */
+#define SSSR_RNE		(1 << 3)	/* Rx FIFO Not Empty */
+#define SSSR_BSY		(1 << 4)	/* SSP Busy */
+#define SSSR_TFS		(1 << 5)	/* Tx FIFO Service Request */
+#define SSSR_RFS		(1 << 6)	/* Rx FIFO Service Request */
+#define SSSR_ROR		(1 << 7)	/* Rx FIFO Overrun */
+#define SSSR_TFL_MASK           (0x0f << 8)     /* Tx FIFO level field mask */
+
+#define SSCR0_TIM    (1 << 23)          /* Transmit FIFO Under Run Int Mask */
+#define SSCR0_RIM    (1 << 22)          /* Receive FIFO Over Run int Mask */
+#define SSCR0_NCS    (1 << 21)          /* Network Clock Select */
+#define SSCR0_EDSS   (1 << 20)          /* Extended Data Size Select */
+
+#define SSCR0_TISSP      (1 << 4)  /* TI Sync Serial Protocol */
+#define SSCR0_PSP        (3 << 4)  /* PSP - Programmable Serial Protocol */
+#define SSCR1_TTELP      (1 << 31) /* TXD Tristate Enable Last Phase */
+#define SSCR1_TTE        (1 << 30) /* TXD Tristate Enable */
+#define SSCR1_EBCEI      (1 << 29) /* Enable Bit Count Error interrupt */
+#define SSCR1_SCFR       (1 << 28) /* Slave Clock free Running */
+#define SSCR1_ECRA       (1 << 27) /* Enable Clock Request A */
+#define SSCR1_ECRB       (1 << 26) /* Enable Clock request B */
+#define SSCR1_SCLKDIR    (1 << 25) /* Serial Bit Rate Clock Direction */
+#define SSCR1_SFRMDIR    (1 << 24) /* Frame Direction */
+#define SSCR1_RWOT       (1 << 23) /* Receive Without Transmit */
+#define SSCR1_TRAIL      (1 << 22) /* Trailing Byte */
+#define SSCR1_TSRE       (1 << 21) /* Transmit Service Request Enable */
+#define SSCR1_RSRE       (1 << 20) /* Receive Service Request Enable */
+#define SSCR1_TINTE      (1 << 19) /* Receiver Time-out Interrupt enable */
+#define SSCR1_PINTE      (1 << 18) /* Trailing Byte Interupt Enable */
+#define SSCR1_STRF       (1 << 15) /* Select FIFO or EFWR */
+#define SSCR1_EFWR       (1 << 14) /* Enable FIFO Write/Read */
+#define SSCR1_IFS        (1 << 16) /* Invert Frame Signal */
+
+#define SSSR_BCE         (1 << 23) /* Bit Count Error */
+#define SSSR_CSS         (1 << 22) /* Clock Synchronisation Status */
+#define SSSR_TUR         (1 << 21) /* Transmit FIFO Under Run */
+#define SSSR_EOC         (1 << 20) /* End Of Chain */
+#define SSSR_TINT        (1 << 19) /* Receiver Time-out Interrupt */
+#define SSSR_PINT        (1 << 18) /* Peripheral Trailing Byte Interrupt */
+
+#define SSPSP_FSRT       (1 << 25)   /* Frame Sync Relative Timing */
+#define SSPSP_DMYSTOP(x) ((x) << 23) /* Dummy Stop */
+#define SSPSP_SFRMWDTH(x)((x) << 16) /* Serial Frame Width */
+#define SSPSP_SFRMDLY(x) ((x) << 9)  /* Serial Frame Delay */
+#define SSPSP_DMYSTRT(x) ((x) << 7)  /* Dummy Start */
+#define SSPSP_STRTDLY(x) ((x) << 4)  /* Start Delay */
+#define SSPSP_ETDS       (1 << 3)    /* End of Transfer data State */
+#define SSPSP_SFRMP      (1 << 2)    /* Serial Frame Polarity */
+#define SSPSP_SCMODE(x)  ((x) << 0)  /* Serial Bit Rate Clock Mode */
+
+/*
+ * For testing SSCR1 changes that require SSP restart, basically
+ * everything except the service and interrupt enables
+ */
+
+#define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
+				| SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
+				| SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
+				| SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
+				| SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
+				| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+
+struct callback_param {
+	void *drv_context;
+	u32 direction;
+};
+
+struct ssp_drv_context {
+	/* Driver model hookup */
+	struct pci_dev *pdev;
+
+	/* SPI framework hookup */
+	struct spi_master *master;
+
+	/* SSP register addresses */
+	unsigned long paddr;
+	void *ioaddr;
+	int irq;
+
+	/* I2C registers */
+	dma_addr_t I2C_paddr;
+	void *I2C_ioaddr;
+
+	/* SSP masks*/
+	u32 cr1_sig;
+	u32 cr1;
+	u32 clear_sr;
+	u32 mask_sr;
+
+	/* PM_QOS request */
+	struct pm_qos_request pm_qos_req;
+
+	struct tasklet_struct poll_transfer;
+
+	spinlock_t lock;
+	struct workqueue_struct *workqueue;
+	struct work_struct pump_messages;
+	struct list_head queue;
+	struct completion msg_done;
+
+	int suspended;
+
+	/* Current message transfer state info */
+	struct spi_message *cur_msg;
+	size_t len;
+	size_t len_dma_rx;
+	size_t len_dma_tx;
+	void *tx;
+	void *tx_end;
+	void *rx;
+	void *rx_end;
+	bool dma_initialized;
+	int dma_mapped;
+	dma_addr_t rx_dma;
+	dma_addr_t tx_dma;
+	u8 n_bytes;
+	int (*write)(struct ssp_drv_context *sspc);
+	int (*read)(struct ssp_drv_context *sspc);
+
+	struct intel_mid_dma_slave    dmas_tx;
+	struct intel_mid_dma_slave    dmas_rx;
+	struct dma_chan    *txchan;
+	struct dma_chan    *rxchan;
+	struct workqueue_struct *dma_wq;
+	struct work_struct complete_work;
+
+	u8 __iomem *virt_addr_sram_tx;
+	u8 __iomem *virt_addr_sram_rx;
+
+	int txdma_done;
+	int rxdma_done;
+	struct callback_param tx_param;
+	struct callback_param rx_param;
+	struct pci_dev *dmac1;
+
+	unsigned long quirks;
+	u32 rx_fifo_threshold;
+};
+
+struct chip_data {
+	u32 cr0;
+	u32 cr1;
+	u32 timeout;
+	u8 chip_select;
+	u8 n_bytes;
+	u8 dma_enabled;
+	u8 bits_per_word;
+	u32 speed_hz;
+	int (*write)(struct ssp_drv_context *sspc);
+	int (*read)(struct ssp_drv_context *sspc);
+};
+
+enum intel_mid_ssp_spi_fifo_burst {
+	IMSS_FIFO_BURST_1,
+	IMSS_FIFO_BURST_4,
+	IMSS_FIFO_BURST_8
+};
+
+/* spi_board_info.controller_data for SPI slave devices,
+ * copied to spi_device.platform_data ... mostly for dma tuning
+ */
+struct intel_mid_ssp_spi_chip {
+	enum intel_mid_ssp_spi_fifo_burst burst_size;
+	u32 timeout;
+	u8 enable_loopback;
+	u8 dma_enabled;
+};
+
+#define SPI_DIB_NAME_LEN  16
+#define SPI_DIB_SPEC_INFO_LEN      10
+
+struct spi_dib_header {
+	u32       signature;
+	u32       length;
+	u8         rev;
+	u8         checksum;
+	u8         dib[0];
+} __packed;
+
+#endif /*INTEL_MID_SSP_SPI_H_*/
-- 
1.8.4.rc3


^ permalink raw reply related	[flat|nested] 36+ messages in thread

* [PATCH 2/2] MAINTAINERS: add Intel MID SSP SPI maintainers
@ 2013-10-29 18:05   ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:05 UTC (permalink / raw)
  To: broonie; +Cc: ning.li, linux-kernel, linux-spi, David Cohen

Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
---
 MAINTAINERS | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 2f60504..8574aa2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1916,6 +1916,14 @@ L:	linux-gpio@vger.kernel.org
 S:	Maintained
 F:	drivers/gpio/gpio-intel-mid.c
 
+INTEL-MID SSP SPI DRIVER
+M:	Ning Li <ning.li@intel.com>
+M:	David Cohen <david.a.cohen@linux.intel.com>
+L:	linux-spi@vger.kernel.org
+S:	Maintained
+F:	drivers/spi/spi-intel-mid-ssp.c
+F:	include/linux/spi/intel_mid_ssp_spi.h
+
 BTRFS FILE SYSTEM
 M:	Chris Mason <chris.mason@fusionio.com>
 L:	linux-btrfs@vger.kernel.org
-- 
1.8.4.rc3


^ permalink raw reply related	[flat|nested] 36+ messages in thread

* [PATCH 2/2] MAINTAINERS: add Intel MID SSP SPI maintainers
@ 2013-10-29 18:05   ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:05 UTC (permalink / raw)
  To: broonie-DgEjT+Ai2ygdnm+yROfE0A
  Cc: ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, David Cohen

Signed-off-by: David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 MAINTAINERS | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 2f60504..8574aa2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1916,6 +1916,14 @@ L:	linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
 S:	Maintained
 F:	drivers/gpio/gpio-intel-mid.c
 
+INTEL-MID SSP SPI DRIVER
+M:	Ning Li <ning.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
+M:	David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
+L:	linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+S:	Maintained
+F:	drivers/spi/spi-intel-mid-ssp.c
+F:	include/linux/spi/intel_mid_ssp_spi.h
+
 BTRFS FILE SYSTEM
 M:	Chris Mason <chris.mason-5c4llco8/ftWk0Htik3J/w@public.gmane.org>
 L:	linux-btrfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
-- 
1.8.4.rc3

--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply related	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
  2013-10-29 18:05 [PATCH 1/2] spi: add Intel Mid SSP driver David Cohen
  2013-10-29 18:05   ` David Cohen
@ 2013-10-29 18:19 ` Joe Perches
  2013-10-29 18:30   ` David Cohen
  2013-10-29 18:29   ` Randy Dunlap
                   ` (3 subsequent siblings)
  5 siblings, 1 reply; 36+ messages in thread
From: Joe Perches @ 2013-10-29 18:19 UTC (permalink / raw)
  To: David Cohen; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
> This patch adds driver for ssp spi interface on Intel Mid platform.

A few simple notes:

Please consider using checkpatch.

> ---
>  drivers/spi/Kconfig                   |   12 +
>  drivers/spi/Makefile                  |    1 +
>  drivers/spi/spi-intel-mid-ssp.c       | 1506 +++++++++++++++++++++++++++++++++
>  include/linux/spi/intel_mid_ssp_spi.h |  330 ++++++++

Shouldn't this include file be in the drivers/spi directory?

[]

> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
[]
> +#ifdef DUMP_RX
> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
> +{

You could save a couple of later #ifdefs by
moving the #ifdef inside the function

static void dump_trailer(etc)
{
#ifdef DUMP_RX
	...
#endif
}

> +static int map_dma_buffers(struct ssp_drv_context *sspc)
> +{
[]
> +#ifdef DUMP_RX
> +		dump_trailer(&sspc->pdev->dev, sspc->tx, sspc->len, 16);
> +#endif

> +static void int_transfer_complete(struct ssp_drv_context *sspc)
> +{
[]
> +#ifdef DUMP_RX
> +	dump_trailer(dev, sspc->rx, sspc->len, 16);
> +#endif

> +static int setup(struct spi_device *spi)
> +{
[]
> +	if (!chip) {
> +		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
> +		if (!chip) {
> +			dev_err(&spi->dev,
> +			"failed setup: can't allocate chip data\n");

OOM messages aren't necessary as a generic OOM message
is already emitted along with a dump_stack();



^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 2/2] MAINTAINERS: add Intel MID SSP SPI maintainers
  2013-10-29 18:05   ` David Cohen
  (?)
@ 2013-10-29 18:20   ` Joe Perches
  2013-10-29 18:33       ` David Cohen
  -1 siblings, 1 reply; 36+ messages in thread
From: Joe Perches @ 2013-10-29 18:20 UTC (permalink / raw)
  To: David Cohen; +Cc: broonie, ning.li, linux-kernel, linux-spi

On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
[]
> diff --git a/MAINTAINERS b/MAINTAINERS
[]
> @@ -1916,6 +1916,14 @@ L:	linux-gpio@vger.kernel.org
>  S:	Maintained
>  F:	drivers/gpio/gpio-intel-mid.c

Please insert this section in alphabetic order.
 
> +INTEL-MID SSP SPI DRIVER
> +M:	Ning Li <ning.li@intel.com>
> +M:	David Cohen <david.a.cohen@linux.intel.com>
> +L:	linux-spi@vger.kernel.org
> +S:	Maintained

Supported?

> +F:	drivers/spi/spi-intel-mid-ssp.c
> +F:	include/linux/spi/intel_mid_ssp_spi.h
> +
>  BTRFS FILE SYSTEM
>  M:	Chris Mason <chris.mason@fusionio.com>
>  L:	linux-btrfs@vger.kernel.org




^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:29   ` Randy Dunlap
  0 siblings, 0 replies; 36+ messages in thread
From: Randy Dunlap @ 2013-10-29 18:29 UTC (permalink / raw)
  To: David Cohen, broonie; +Cc: ning.li, linux-kernel, linux-spi, Fei Yang

Hi,
Here are a few comments for your next version.


On 10/29/13 11:05, David Cohen wrote:
> From: Fei Yang <fei.yang@intel.com>
> 
> This patch adds driver for ssp spi interface on Intel Mid platform.
> 
> Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
> Signed-off-by: Fei Yang <fei.yang@intel.com>
> Reviewed-by: Ning Li <ning.li@intel.com>
> ---
>  drivers/spi/Kconfig                   |   12 +
>  drivers/spi/Makefile                  |    1 +
>  drivers/spi/spi-intel-mid-ssp.c       | 1506 +++++++++++++++++++++++++++++++++
>  include/linux/spi/intel_mid_ssp_spi.h |  330 ++++++++
>  4 files changed, 1849 insertions(+)
>  create mode 100644 drivers/spi/spi-intel-mid-ssp.c
>  create mode 100644 include/linux/spi/intel_mid_ssp_spi.h
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index b9c53cc..e211829 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -211,6 +211,18 @@ config SPI_IMX
>  	  This enables using the Freescale i.MX SPI controllers in master
>  	  mode.
>  
> +config SPI_INTEL_MID_SSP
> +	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
> +	depends on X86_INTEL_MID && SPI_MASTER && INTEL_MID_DMAC
> +	help
> +	  Select Y or M to build the unified SSP SPI slave controller driver
> +	  for the Intel MID platforms (Medfield, Clovertrail and Merrifield),
> +	  primarily used to implement a SPI host controller driver over a SSP

I would say:
	                              an SPI                            an SSP

> +	  host controller.
> +
> +	  If you choose to build this driver as module it will be called
> +	  spi-intel-mid-ssp.ko
> +
>  config SPI_LM70_LLP
>  	tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)"
>  	depends on PARPORT
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index ab8d864..60c8a1e 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_SPI_FSL_ESPI)		+= spi-fsl-espi.o
>  obj-$(CONFIG_SPI_FSL_SPI)		+= spi-fsl-spi.o
>  obj-$(CONFIG_SPI_GPIO)			+= spi-gpio.o
>  obj-$(CONFIG_SPI_IMX)			+= spi-imx.o
> +obj-$(CONFIG_SPI_INTEL_MID_SSP)		+= spi-intel-mid-ssp.o
>  obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
>  obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
>  obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
> new file mode 100644
> index 0000000..b3b9fe8
> --- /dev/null
> +++ b/drivers/spi/spi-intel-mid-ssp.c
> @@ -0,0 +1,1506 @@
> +/*
> + * spi-intel-mid-ssp.c
> + * This driver supports Bulverde SSP core used on Intel MID platforms
> + * It supports SSP of Moorestown & Medfield platforms and handles clock
> + * slave & master modes.
> + *
> + * Copyright (c) 2013, Intel Corporation.
> + * Contacts: Ning Li <ning.li@intel.com>
> + *	     David Cohen <david.a.cohen@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> + *
> + */
> +
> +/*
> + * Note:
> + *
> + * Supports DMA and non-interrupt polled transfers.
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/highmem.h>
> +#include <linux/pci.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/intel_mid_dma.h>
> +#include <linux/pm_qos.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/completion.h>
> +#include <asm/intel-mid.h>
> +
> +#include <linux/spi/spi.h>
> +#include <linux/spi/intel_mid_ssp_spi.h>
> +
> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
> +
> +static int ssp_timing_wr;
> +
> +#ifdef DUMP_RX
> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
> +{
> +	int tlen1 = (len < sz ? len : sz);
> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
> +	unsigned char *p;
> +	static char msg[MAX_SPI_TRANSFER_SIZE];
> +

#include <linux/printk.h>

and try to use print_hex_dump() for this instead of rolling your own...

> +	memset(msg, '\0', sizeof(msg));
> +	p = buf;
> +	while (p < buf + tlen1)
> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +
> +	if (tlen2 > 0) {
> +		sprintf(msg, "%s .....", msg);
> +		p = (buf+len) - tlen2;
> +		while (p < buf + len)
> +			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +	}
> +
> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
> +		   len-tlen2, len - 1, msg);
> +}
> +#endif
> +
> +static void flush(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	u32 i = 0;
> +
> +	/* If the transmit fifo is not empty, reset the interface. */
> +	if (!is_tx_fifo_empty(sspc)) {
> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
> +		disable_interface(sspc);
> +		return;
> +	}
> +
> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
> +		read_SSDR(reg);
> +		i++;
> +	}
> +	WARN(i > 0, "%d words flush occured\n", i);

	                            occurred

> +
> +	return;
> +}
> +
> +
> +
> +	/* set the dma done bit to 1 */

unneeded comment (obvious)

> +	sspc->txdma_done = 1;
> +	sspc->rxdma_done = 1;
> +
> +	sspc->tx_param.drv_context  = sspc;
> +	sspc->tx_param.direction = TX_DIRECTION;
> +	sspc->rx_param.drv_context  = sspc;
> +	sspc->rx_param.direction = RX_DIRECTION;
> +
> +	sspc->dma_initialized = 1;
> +	return;

> +/**
> + * map_dma_buffers() - Map DMA buffer before a transfer
> + * @sspc:	Pointer to the private drivzer context

		                       driver

> +static void poll_transfer_complete(struct ssp_drv_context *sspc)
> +{
> +	struct spi_message *msg;
> +
> +	/* Update total byte transfered return count actual bytes read */

	                     transferred;

> +	sspc->cur_msg->actual_length += sspc->len - (sspc->rx_end - sspc->rx);
> +
> +	sspc->cur_msg->status = 0;
> +	msg = sspc->cur_msg;
> +	if (likely(msg->complete))
> +		msg->complete(msg->context);
> +	complete(&sspc->msg_done);
> +}
> +
> +/**
> + * ssp_int() - Interrupt handler
> + * @irq
> + * @dev_id

Please finish the kernel-doc notation (or drop it).

> + *
> + * The SSP interrupt is not used for transfer which are handled by
> + * DMA or polling: only under/over run are catched to detect
> + * broken transfers.
> + */
> +static irqreturn_t ssp_int(int irq, void *dev_id)
> +{
> +	struct ssp_drv_context *sspc = dev_id;
> +	void *reg = sspc->ioaddr;
> +	struct device *dev = &sspc->pdev->dev;
> +	u32 status = read_SSSR(reg);
> +
> +	/* It should never be our interrupt since SSP will */
> +	/* only trigs interrupt for under/over run.        */

	        trigger

> +	if (likely(!(status & sspc->mask_sr)))
> +		return IRQ_NONE;
> +
> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
> +		WARN_ON(1);
> +		if (status & SSSR_ROR)
> +			dev_err(dev, "we have Overrun\n");
> +		if (status & SSSR_TUR)
> +			dev_err(dev, "we have Underrun\n");
> +	}
> +
> +	/* We can fall here when not using DMA mode */
> +	if (!sspc->cur_msg) {
> +		disable_interface(sspc);
> +		disable_triggers(sspc);
> +	}
> +	/* clear status register */
> +	write_SSSR(sspc->clear_sr, reg);
> +	return IRQ_HANDLED;
> +}
> +


> diff --git a/include/linux/spi/intel_mid_ssp_spi.h b/include/linux/spi/intel_mid_ssp_spi.h
> new file mode 100644
> index 0000000..a3bb973
> --- /dev/null
> +++ b/include/linux/spi/intel_mid_ssp_spi.h
> @@ -0,0 +1,330 @@
> +/*
> + *  Copyright (C) Intel 2013
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with this program; if not, write to the Free Software
> + *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + */
> +#ifndef INTEL_MID_SSP_SPI_H_
> +#define INTEL_MID_SSP_SPI_H_
> +
> +#include <linux/completion.h>
> +#include <linux/intel_mid_dma.h>
> +#include <linux/interrupt.h>
> +#include <linux/pm_qos.h>
> +#include <linux/spi/spi.h>
> +

> +#define SSCR0_DSS   (0x0000000f)     /* Data Size Select (mask) */
> +#define SSCR0_DataSize(x)  ((x) - 1)    /* Data Size Select [4..16] */
> +#define SSCR0_FRF   (0x00000030)     /* FRame Format (mask) */
> +#define SSCR0_Motorola        (0x0 << 4)         /* Motorola's SPI mode */

#include <linux/bitops.h>

> +#define SSCR0_ECS   (1 << 6) /* External clock select */

#define SSCR0_ECS	BIT(6)	/* External clock select */

etc.

> +#define SSCR0_SSE   (1 << 7) /* Synchronous Serial Port Enable */
> +
> +#define SSCR0_SCR   (0x000fff00)      /* Serial Clock Rate (mask) */
> +#define SSCR0_SerClkDiv(x) (((x) - 1) << 8) /* Divisor [1..4096] */
> +#define SSCR0_EDSS  (1 << 20)           /* Extended data size select */
> +#define SSCR0_NCS   (1 << 21)           /* Network clock select */
> +#define SSCR0_RIM    (1 << 22)           /* Receive FIFO overrrun int mask */
> +#define SSCR0_TUM   (1 << 23)           /* Transmit FIFO underrun int mask */
> +#define SSCR0_FRDC (0x07000000)     /* Frame rate divider control (mask) */
> +#define SSCR0_SlotsPerFrm(x) (((x) - 1) << 24) /* Time slots per frame */
> +#define SSCR0_ADC   (1 << 30)           /* Audio clock select */
> +#define SSCR0_MOD  (1 << 31)           /* Mode (normal or network) */
> +
> +#define SSCR1_RIE    (1 << 0) /* Receive FIFO Interrupt Enable */
> +#define SSCR1_TIE     (1 << 1) /* Transmit FIFO Interrupt Enable */
> +#define SSCR1_LBM   (1 << 2) /* Loop-Back Mode */
> +#define SSCR1_SPO   (1 << 3) /* SSPSCLK polarity setting */
> +#define SSCR1_SPH   (1 << 4) /* Motorola SPI SSPSCLK phase setting */
> +#define SSCR1_MWDS           (1 << 5) /* Microwire Transmit Data Size */
> +#define SSCR1_TFT    (0x000003c0)     /* Transmit FIFO Threshold (mask) */
> +#define SSCR1_TxTresh(x) (((x) - 1) << 6) /* level [1..16] */
> +#define SSCR1_RFT    (0x00003c00)     /* Receive FIFO Threshold (mask) */
> +#define SSCR1_RxTresh(x) (((x) - 1) << 10) /* level [1..16] */
> +
> +#define SSSR_TNF		(1 << 2)	/* Tx FIFO Not Full */
> +#define SSSR_RNE		(1 << 3)	/* Rx FIFO Not Empty */
> +#define SSSR_BSY		(1 << 4)	/* SSP Busy */
> +#define SSSR_TFS		(1 << 5)	/* Tx FIFO Service Request */
> +#define SSSR_RFS		(1 << 6)	/* Rx FIFO Service Request */
> +#define SSSR_ROR		(1 << 7)	/* Rx FIFO Overrun */
> +#define SSSR_TFL_MASK           (0x0f << 8)     /* Tx FIFO level field mask */
> +
> +#define SSCR0_TIM    (1 << 23)          /* Transmit FIFO Under Run Int Mask */
> +#define SSCR0_RIM    (1 << 22)          /* Receive FIFO Over Run int Mask */
> +#define SSCR0_NCS    (1 << 21)          /* Network Clock Select */
> +#define SSCR0_EDSS   (1 << 20)          /* Extended Data Size Select */
> +
> +#define SSCR0_TISSP      (1 << 4)  /* TI Sync Serial Protocol */
> +#define SSCR0_PSP        (3 << 4)  /* PSP - Programmable Serial Protocol */
> +#define SSCR1_TTELP      (1 << 31) /* TXD Tristate Enable Last Phase */
> +#define SSCR1_TTE        (1 << 30) /* TXD Tristate Enable */
> +#define SSCR1_EBCEI      (1 << 29) /* Enable Bit Count Error interrupt */
> +#define SSCR1_SCFR       (1 << 28) /* Slave Clock free Running */
> +#define SSCR1_ECRA       (1 << 27) /* Enable Clock Request A */
> +#define SSCR1_ECRB       (1 << 26) /* Enable Clock request B */
> +#define SSCR1_SCLKDIR    (1 << 25) /* Serial Bit Rate Clock Direction */
> +#define SSCR1_SFRMDIR    (1 << 24) /* Frame Direction */
> +#define SSCR1_RWOT       (1 << 23) /* Receive Without Transmit */
> +#define SSCR1_TRAIL      (1 << 22) /* Trailing Byte */
> +#define SSCR1_TSRE       (1 << 21) /* Transmit Service Request Enable */
> +#define SSCR1_RSRE       (1 << 20) /* Receive Service Request Enable */
> +#define SSCR1_TINTE      (1 << 19) /* Receiver Time-out Interrupt enable */
> +#define SSCR1_PINTE      (1 << 18) /* Trailing Byte Interupt Enable */
> +#define SSCR1_STRF       (1 << 15) /* Select FIFO or EFWR */
> +#define SSCR1_EFWR       (1 << 14) /* Enable FIFO Write/Read */
> +#define SSCR1_IFS        (1 << 16) /* Invert Frame Signal */
> +
> +#define SSSR_BCE         (1 << 23) /* Bit Count Error */
> +#define SSSR_CSS         (1 << 22) /* Clock Synchronisation Status */
> +#define SSSR_TUR         (1 << 21) /* Transmit FIFO Under Run */
> +#define SSSR_EOC         (1 << 20) /* End Of Chain */
> +#define SSSR_TINT        (1 << 19) /* Receiver Time-out Interrupt */
> +#define SSSR_PINT        (1 << 18) /* Peripheral Trailing Byte Interrupt */
> +
> +#define SSPSP_FSRT       (1 << 25)   /* Frame Sync Relative Timing */
> +#define SSPSP_DMYSTOP(x) ((x) << 23) /* Dummy Stop */
> +#define SSPSP_SFRMWDTH(x)((x) << 16) /* Serial Frame Width */
> +#define SSPSP_SFRMDLY(x) ((x) << 9)  /* Serial Frame Delay */
> +#define SSPSP_DMYSTRT(x) ((x) << 7)  /* Dummy Start */
> +#define SSPSP_STRTDLY(x) ((x) << 4)  /* Start Delay */
> +#define SSPSP_ETDS       (1 << 3)    /* End of Transfer data State */
> +#define SSPSP_SFRMP      (1 << 2)    /* Serial Frame Polarity */
> +#define SSPSP_SCMODE(x)  ((x) << 0)  /* Serial Bit Rate Clock Mode */


-- 
~Randy

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:29   ` Randy Dunlap
  0 siblings, 0 replies; 36+ messages in thread
From: Randy Dunlap @ 2013-10-29 18:29 UTC (permalink / raw)
  To: David Cohen, broonie-DgEjT+Ai2ygdnm+yROfE0A
  Cc: ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

Hi,
Here are a few comments for your next version.


On 10/29/13 11:05, David Cohen wrote:
> From: Fei Yang <fei.yang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> 
> This patch adds driver for ssp spi interface on Intel Mid platform.
> 
> Signed-off-by: David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Signed-off-by: Fei Yang <fei.yang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Reviewed-by: Ning Li <ning.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
>  drivers/spi/Kconfig                   |   12 +
>  drivers/spi/Makefile                  |    1 +
>  drivers/spi/spi-intel-mid-ssp.c       | 1506 +++++++++++++++++++++++++++++++++
>  include/linux/spi/intel_mid_ssp_spi.h |  330 ++++++++
>  4 files changed, 1849 insertions(+)
>  create mode 100644 drivers/spi/spi-intel-mid-ssp.c
>  create mode 100644 include/linux/spi/intel_mid_ssp_spi.h
> 
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index b9c53cc..e211829 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -211,6 +211,18 @@ config SPI_IMX
>  	  This enables using the Freescale i.MX SPI controllers in master
>  	  mode.
>  
> +config SPI_INTEL_MID_SSP
> +	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
> +	depends on X86_INTEL_MID && SPI_MASTER && INTEL_MID_DMAC
> +	help
> +	  Select Y or M to build the unified SSP SPI slave controller driver
> +	  for the Intel MID platforms (Medfield, Clovertrail and Merrifield),
> +	  primarily used to implement a SPI host controller driver over a SSP

I would say:
	                              an SPI                            an SSP

> +	  host controller.
> +
> +	  If you choose to build this driver as module it will be called
> +	  spi-intel-mid-ssp.ko
> +
>  config SPI_LM70_LLP
>  	tristate "Parallel port adapter for LM70 eval board (DEVELOPMENT)"
>  	depends on PARPORT
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index ab8d864..60c8a1e 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_SPI_FSL_ESPI)		+= spi-fsl-espi.o
>  obj-$(CONFIG_SPI_FSL_SPI)		+= spi-fsl-spi.o
>  obj-$(CONFIG_SPI_GPIO)			+= spi-gpio.o
>  obj-$(CONFIG_SPI_IMX)			+= spi-imx.o
> +obj-$(CONFIG_SPI_INTEL_MID_SSP)		+= spi-intel-mid-ssp.o
>  obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
>  obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
>  obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
> new file mode 100644
> index 0000000..b3b9fe8
> --- /dev/null
> +++ b/drivers/spi/spi-intel-mid-ssp.c
> @@ -0,0 +1,1506 @@
> +/*
> + * spi-intel-mid-ssp.c
> + * This driver supports Bulverde SSP core used on Intel MID platforms
> + * It supports SSP of Moorestown & Medfield platforms and handles clock
> + * slave & master modes.
> + *
> + * Copyright (c) 2013, Intel Corporation.
> + * Contacts: Ning Li <ning.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> + *	     David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> + *
> + */
> +
> +/*
> + * Note:
> + *
> + * Supports DMA and non-interrupt polled transfers.
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/highmem.h>
> +#include <linux/pci.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/intel_mid_dma.h>
> +#include <linux/pm_qos.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/completion.h>
> +#include <asm/intel-mid.h>
> +
> +#include <linux/spi/spi.h>
> +#include <linux/spi/intel_mid_ssp_spi.h>
> +
> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
> +
> +static int ssp_timing_wr;
> +
> +#ifdef DUMP_RX
> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
> +{
> +	int tlen1 = (len < sz ? len : sz);
> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
> +	unsigned char *p;
> +	static char msg[MAX_SPI_TRANSFER_SIZE];
> +

#include <linux/printk.h>

and try to use print_hex_dump() for this instead of rolling your own...

> +	memset(msg, '\0', sizeof(msg));
> +	p = buf;
> +	while (p < buf + tlen1)
> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +
> +	if (tlen2 > 0) {
> +		sprintf(msg, "%s .....", msg);
> +		p = (buf+len) - tlen2;
> +		while (p < buf + len)
> +			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +	}
> +
> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
> +		   len-tlen2, len - 1, msg);
> +}
> +#endif
> +
> +static void flush(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	u32 i = 0;
> +
> +	/* If the transmit fifo is not empty, reset the interface. */
> +	if (!is_tx_fifo_empty(sspc)) {
> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
> +		disable_interface(sspc);
> +		return;
> +	}
> +
> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
> +		read_SSDR(reg);
> +		i++;
> +	}
> +	WARN(i > 0, "%d words flush occured\n", i);

	                            occurred

> +
> +	return;
> +}
> +
> +
> +
> +	/* set the dma done bit to 1 */

unneeded comment (obvious)

> +	sspc->txdma_done = 1;
> +	sspc->rxdma_done = 1;
> +
> +	sspc->tx_param.drv_context  = sspc;
> +	sspc->tx_param.direction = TX_DIRECTION;
> +	sspc->rx_param.drv_context  = sspc;
> +	sspc->rx_param.direction = RX_DIRECTION;
> +
> +	sspc->dma_initialized = 1;
> +	return;

> +/**
> + * map_dma_buffers() - Map DMA buffer before a transfer
> + * @sspc:	Pointer to the private drivzer context

		                       driver

> +static void poll_transfer_complete(struct ssp_drv_context *sspc)
> +{
> +	struct spi_message *msg;
> +
> +	/* Update total byte transfered return count actual bytes read */

	                     transferred;

> +	sspc->cur_msg->actual_length += sspc->len - (sspc->rx_end - sspc->rx);
> +
> +	sspc->cur_msg->status = 0;
> +	msg = sspc->cur_msg;
> +	if (likely(msg->complete))
> +		msg->complete(msg->context);
> +	complete(&sspc->msg_done);
> +}
> +
> +/**
> + * ssp_int() - Interrupt handler
> + * @irq
> + * @dev_id

Please finish the kernel-doc notation (or drop it).

> + *
> + * The SSP interrupt is not used for transfer which are handled by
> + * DMA or polling: only under/over run are catched to detect
> + * broken transfers.
> + */
> +static irqreturn_t ssp_int(int irq, void *dev_id)
> +{
> +	struct ssp_drv_context *sspc = dev_id;
> +	void *reg = sspc->ioaddr;
> +	struct device *dev = &sspc->pdev->dev;
> +	u32 status = read_SSSR(reg);
> +
> +	/* It should never be our interrupt since SSP will */
> +	/* only trigs interrupt for under/over run.        */

	        trigger

> +	if (likely(!(status & sspc->mask_sr)))
> +		return IRQ_NONE;
> +
> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
> +		WARN_ON(1);
> +		if (status & SSSR_ROR)
> +			dev_err(dev, "we have Overrun\n");
> +		if (status & SSSR_TUR)
> +			dev_err(dev, "we have Underrun\n");
> +	}
> +
> +	/* We can fall here when not using DMA mode */
> +	if (!sspc->cur_msg) {
> +		disable_interface(sspc);
> +		disable_triggers(sspc);
> +	}
> +	/* clear status register */
> +	write_SSSR(sspc->clear_sr, reg);
> +	return IRQ_HANDLED;
> +}
> +


> diff --git a/include/linux/spi/intel_mid_ssp_spi.h b/include/linux/spi/intel_mid_ssp_spi.h
> new file mode 100644
> index 0000000..a3bb973
> --- /dev/null
> +++ b/include/linux/spi/intel_mid_ssp_spi.h
> @@ -0,0 +1,330 @@
> +/*
> + *  Copyright (C) Intel 2013
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.
> + *
> + *  This program is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with this program; if not, write to the Free Software
> + *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + */
> +#ifndef INTEL_MID_SSP_SPI_H_
> +#define INTEL_MID_SSP_SPI_H_
> +
> +#include <linux/completion.h>
> +#include <linux/intel_mid_dma.h>
> +#include <linux/interrupt.h>
> +#include <linux/pm_qos.h>
> +#include <linux/spi/spi.h>
> +

> +#define SSCR0_DSS   (0x0000000f)     /* Data Size Select (mask) */
> +#define SSCR0_DataSize(x)  ((x) - 1)    /* Data Size Select [4..16] */
> +#define SSCR0_FRF   (0x00000030)     /* FRame Format (mask) */
> +#define SSCR0_Motorola        (0x0 << 4)         /* Motorola's SPI mode */

#include <linux/bitops.h>

> +#define SSCR0_ECS   (1 << 6) /* External clock select */

#define SSCR0_ECS	BIT(6)	/* External clock select */

etc.

> +#define SSCR0_SSE   (1 << 7) /* Synchronous Serial Port Enable */
> +
> +#define SSCR0_SCR   (0x000fff00)      /* Serial Clock Rate (mask) */
> +#define SSCR0_SerClkDiv(x) (((x) - 1) << 8) /* Divisor [1..4096] */
> +#define SSCR0_EDSS  (1 << 20)           /* Extended data size select */
> +#define SSCR0_NCS   (1 << 21)           /* Network clock select */
> +#define SSCR0_RIM    (1 << 22)           /* Receive FIFO overrrun int mask */
> +#define SSCR0_TUM   (1 << 23)           /* Transmit FIFO underrun int mask */
> +#define SSCR0_FRDC (0x07000000)     /* Frame rate divider control (mask) */
> +#define SSCR0_SlotsPerFrm(x) (((x) - 1) << 24) /* Time slots per frame */
> +#define SSCR0_ADC   (1 << 30)           /* Audio clock select */
> +#define SSCR0_MOD  (1 << 31)           /* Mode (normal or network) */
> +
> +#define SSCR1_RIE    (1 << 0) /* Receive FIFO Interrupt Enable */
> +#define SSCR1_TIE     (1 << 1) /* Transmit FIFO Interrupt Enable */
> +#define SSCR1_LBM   (1 << 2) /* Loop-Back Mode */
> +#define SSCR1_SPO   (1 << 3) /* SSPSCLK polarity setting */
> +#define SSCR1_SPH   (1 << 4) /* Motorola SPI SSPSCLK phase setting */
> +#define SSCR1_MWDS           (1 << 5) /* Microwire Transmit Data Size */
> +#define SSCR1_TFT    (0x000003c0)     /* Transmit FIFO Threshold (mask) */
> +#define SSCR1_TxTresh(x) (((x) - 1) << 6) /* level [1..16] */
> +#define SSCR1_RFT    (0x00003c00)     /* Receive FIFO Threshold (mask) */
> +#define SSCR1_RxTresh(x) (((x) - 1) << 10) /* level [1..16] */
> +
> +#define SSSR_TNF		(1 << 2)	/* Tx FIFO Not Full */
> +#define SSSR_RNE		(1 << 3)	/* Rx FIFO Not Empty */
> +#define SSSR_BSY		(1 << 4)	/* SSP Busy */
> +#define SSSR_TFS		(1 << 5)	/* Tx FIFO Service Request */
> +#define SSSR_RFS		(1 << 6)	/* Rx FIFO Service Request */
> +#define SSSR_ROR		(1 << 7)	/* Rx FIFO Overrun */
> +#define SSSR_TFL_MASK           (0x0f << 8)     /* Tx FIFO level field mask */
> +
> +#define SSCR0_TIM    (1 << 23)          /* Transmit FIFO Under Run Int Mask */
> +#define SSCR0_RIM    (1 << 22)          /* Receive FIFO Over Run int Mask */
> +#define SSCR0_NCS    (1 << 21)          /* Network Clock Select */
> +#define SSCR0_EDSS   (1 << 20)          /* Extended Data Size Select */
> +
> +#define SSCR0_TISSP      (1 << 4)  /* TI Sync Serial Protocol */
> +#define SSCR0_PSP        (3 << 4)  /* PSP - Programmable Serial Protocol */
> +#define SSCR1_TTELP      (1 << 31) /* TXD Tristate Enable Last Phase */
> +#define SSCR1_TTE        (1 << 30) /* TXD Tristate Enable */
> +#define SSCR1_EBCEI      (1 << 29) /* Enable Bit Count Error interrupt */
> +#define SSCR1_SCFR       (1 << 28) /* Slave Clock free Running */
> +#define SSCR1_ECRA       (1 << 27) /* Enable Clock Request A */
> +#define SSCR1_ECRB       (1 << 26) /* Enable Clock request B */
> +#define SSCR1_SCLKDIR    (1 << 25) /* Serial Bit Rate Clock Direction */
> +#define SSCR1_SFRMDIR    (1 << 24) /* Frame Direction */
> +#define SSCR1_RWOT       (1 << 23) /* Receive Without Transmit */
> +#define SSCR1_TRAIL      (1 << 22) /* Trailing Byte */
> +#define SSCR1_TSRE       (1 << 21) /* Transmit Service Request Enable */
> +#define SSCR1_RSRE       (1 << 20) /* Receive Service Request Enable */
> +#define SSCR1_TINTE      (1 << 19) /* Receiver Time-out Interrupt enable */
> +#define SSCR1_PINTE      (1 << 18) /* Trailing Byte Interupt Enable */
> +#define SSCR1_STRF       (1 << 15) /* Select FIFO or EFWR */
> +#define SSCR1_EFWR       (1 << 14) /* Enable FIFO Write/Read */
> +#define SSCR1_IFS        (1 << 16) /* Invert Frame Signal */
> +
> +#define SSSR_BCE         (1 << 23) /* Bit Count Error */
> +#define SSSR_CSS         (1 << 22) /* Clock Synchronisation Status */
> +#define SSSR_TUR         (1 << 21) /* Transmit FIFO Under Run */
> +#define SSSR_EOC         (1 << 20) /* End Of Chain */
> +#define SSSR_TINT        (1 << 19) /* Receiver Time-out Interrupt */
> +#define SSSR_PINT        (1 << 18) /* Peripheral Trailing Byte Interrupt */
> +
> +#define SSPSP_FSRT       (1 << 25)   /* Frame Sync Relative Timing */
> +#define SSPSP_DMYSTOP(x) ((x) << 23) /* Dummy Stop */
> +#define SSPSP_SFRMWDTH(x)((x) << 16) /* Serial Frame Width */
> +#define SSPSP_SFRMDLY(x) ((x) << 9)  /* Serial Frame Delay */
> +#define SSPSP_DMYSTRT(x) ((x) << 7)  /* Dummy Start */
> +#define SSPSP_STRTDLY(x) ((x) << 4)  /* Start Delay */
> +#define SSPSP_ETDS       (1 << 3)    /* End of Transfer data State */
> +#define SSPSP_SFRMP      (1 << 2)    /* Serial Frame Polarity */
> +#define SSPSP_SCMODE(x)  ((x) << 0)  /* Serial Bit Rate Clock Mode */


-- 
~Randy
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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
  2013-10-29 18:19 ` [PATCH 1/2] spi: add Intel Mid SSP driver Joe Perches
@ 2013-10-29 18:30   ` David Cohen
  2013-10-29 18:35       ` Joe Perches
  0 siblings, 1 reply; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:30 UTC (permalink / raw)
  To: Joe Perches; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

Hi Joe,

On 10/29/2013 11:19 AM, Joe Perches wrote:
> On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
>> This patch adds driver for ssp spi interface on Intel Mid platform.
>
> A few simple notes:
>
> Please consider using checkpatch.

I did and got no warnings. But haven't used --strict option.

>
>> ---
>>   drivers/spi/Kconfig                   |   12 +
>>   drivers/spi/Makefile                  |    1 +
>>   drivers/spi/spi-intel-mid-ssp.c       | 1506 +++++++++++++++++++++++++++++++++
>>   include/linux/spi/intel_mid_ssp_spi.h |  330 ++++++++
>
> Shouldn't this include file be in the drivers/spi directory?

I can't be. This header file will be needed by Intel MID platform code
located under arch/x86/platform/intel-mid/ directory.

>
> []
>
>> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
> []
>> +#ifdef DUMP_RX
>> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
>> +{
>
> You could save a couple of later #ifdefs by
> moving the #ifdef inside the function

I can do that.

>
> static void dump_trailer(etc)
> {
> #ifdef DUMP_RX
> 	...
> #endif
> }
>
>> +static int map_dma_buffers(struct ssp_drv_context *sspc)
>> +{
> []
>> +#ifdef DUMP_RX
>> +		dump_trailer(&sspc->pdev->dev, sspc->tx, sspc->len, 16);
>> +#endif
>
>> +static void int_transfer_complete(struct ssp_drv_context *sspc)
>> +{
> []
>> +#ifdef DUMP_RX
>> +	dump_trailer(dev, sspc->rx, sspc->len, 16);
>> +#endif
>
>> +static int setup(struct spi_device *spi)
>> +{
> []
>> +	if (!chip) {
>> +		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
>> +		if (!chip) {
>> +			dev_err(&spi->dev,
>> +			"failed setup: can't allocate chip data\n");
>
> OOM messages aren't necessary as a generic OOM message
> is already emitted along with a dump_stack();

So I'll remove the message.

Thanks for your feedback. A new version is coming soon.

Br, David Cohen


^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:31   ` Felipe Balbi
  0 siblings, 0 replies; 36+ messages in thread
From: Felipe Balbi @ 2013-10-29 18:31 UTC (permalink / raw)
  To: David Cohen; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

[-- Attachment #1: Type: text/plain, Size: 14815 bytes --]

Hi,

On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
> new file mode 100644
> index 0000000..b3b9fe8
> --- /dev/null
> +++ b/drivers/spi/spi-intel-mid-ssp.c
> @@ -0,0 +1,1506 @@
> +/*
> + * spi-intel-mid-ssp.c
> + * This driver supports Bulverde SSP core used on Intel MID platforms
> + * It supports SSP of Moorestown & Medfield platforms and handles clock
> + * slave & master modes.
> + *
> + * Copyright (c) 2013, Intel Corporation.
> + * Contacts: Ning Li <ning.li@intel.com>
> + *	     David Cohen <david.a.cohen@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> + *
> + */
> +
> +/*
> + * Note:
> + *
> + * Supports DMA and non-interrupt polled transfers.
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/highmem.h>
> +#include <linux/pci.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/intel_mid_dma.h>
> +#include <linux/pm_qos.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/completion.h>
> +#include <asm/intel-mid.h>
> +
> +#include <linux/spi/spi.h>
> +#include <linux/spi/intel_mid_ssp_spi.h>
> +
> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
> +
> +static int ssp_timing_wr;

this will prevent multiple instances of the same driver.

> +#ifdef DUMP_RX
> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
> +{
> +	int tlen1 = (len < sz ? len : sz);
> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
> +	unsigned char *p;
> +	static char msg[MAX_SPI_TRANSFER_SIZE];
> +
> +	memset(msg, '\0', sizeof(msg));
> +	p = buf;
> +	while (p < buf + tlen1)
> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +
> +	if (tlen2 > 0) {
> +		sprintf(msg, "%s .....", msg);
> +		p = (buf+len) - tlen2;
> +		while (p < buf + len)
> +			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +	}
> +
> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
> +		   len-tlen2, len - 1, msg);
> +}
> +#endif

either move this to debugfs or stub the function out ifndef DUMP_RX,
then you don't need the ifdefs when calling it.

> +static inline u8 ssp_cfg_get_mode(u8 ssp_cfg)
> +{
> +	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)

instead, couldn't you use driver data to pass some flags to the driver ?
I can't see intel_mid_identify_cpu and having drivers depend on
arch-specific code is usually a bad practice.

> +		return (ssp_cfg) & 0x03;
> +	else

else isn't needed here

> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +	u32 sssr;

blank line here would aid readability

> +	sssr = read_SSSR(sspc->ioaddr);
> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
> +		return 0;
> +	else

else isn't necessary

> +static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +	return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);

you don't need the outter parenthesis here, GCC should've warned you,
even.

> +static inline void disable_interface(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line here

> +	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
> +}
> +
> +static inline void disable_triggers(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

and here...

> +	write_SSCR1(read_SSCR1(reg) & ~sspc->cr1_sig, reg);
> +}
> +
> +
> +static void flush(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	u32 i = 0;
> +
> +	/* If the transmit fifo is not empty, reset the interface. */
> +	if (!is_tx_fifo_empty(sspc)) {
> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
> +		disable_interface(sspc);
> +		return;
> +	}

not so sure, if the transmit fifo isn't empty and you reset it, you
could end up corrupting data which is about to be shifted into the wire,
couldn't you ?

Is this a case which would *really* happen in normal conditions ? If so,
why ?

> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
> +		read_SSDR(reg);
> +		i++;
> +	}
> +	WARN(i > 0, "%d words flush occured\n", i);

similarly, you could be ignoring data you *should* indeed be handling.

> +
> +	return;

return statement is unnecessary.

> +static int null_writer(struct ssp_drv_context *sspc)

looks like these two functions (null_\(writer\|reader\)) need some
documentation. Why do they exist ?

> +static int u8_writer(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> +		|| (sspc->tx == sspc->tx_end))
> +		return 0;
> +
> +	write_SSDR(*(u8 *)(sspc->tx), reg);
> +	++sspc->tx;
> +
> +	return 1;
> +}
> +
> +static int u8_reader(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	while ((read_SSSR(reg) & SSSR_RNE)
> +		&& (sspc->rx < sspc->rx_end)) {
> +		*(u8 *)(sspc->rx) = read_SSDR(reg);
> +		++sspc->rx;
> +	}
> +
> +	return sspc->rx == sspc->rx_end;
> +}
> +
> +static int u16_writer(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)

the extra comparisson here is superfluous.

> +		|| (sspc->tx == sspc->tx_end))
> +		return 0;
> +
> +	write_SSDR(*(u16 *)(sspc->tx), reg);
> +	sspc->tx += 2;
> +
> +	return 1;
> +}
> +
> +static int u16_reader(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
> +		*(u16 *)(sspc->rx) = read_SSDR(reg);
> +		sspc->rx += 2;
> +	}
> +
> +	return sspc->rx == sspc->rx_end;
> +}
> +
> +static int u32_writer(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)

the extra comparisson here is superfluous.

> +		|| (sspc->tx == sspc->tx_end))
> +		return 0;
> +
> +	write_SSDR(*(u32 *)(sspc->tx), reg);
> +	sspc->tx += 4;
> +
> +	return 1;
> +}
> +
> +static int u32_reader(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
> +		*(u32 *)(sspc->rx) = read_SSDR(reg);
> +		sspc->rx += 4;
> +	}
> +
> +	return sspc->rx == sspc->rx_end;
> +}
> +
> +static bool chan_filter(struct dma_chan *chan, void *param)
> +{
> +	struct ssp_drv_context *sspc = param;
> +
> +	if (sspc->dmac1 && chan->device->dev == &sspc->dmac1->dev)
> +		return true;
> +
> +	return false;
> +}
> +
> +/**
> + * unmap_dma_buffers() - Unmap the DMA buffers used during the last transfer.
> + * @sspc:	Pointer to the private driver context
> + */
> +static void unmap_dma_buffers(struct ssp_drv_context *sspc)
> +{
> +	struct device *dev = &sspc->pdev->dev;
> +
> +	if (!sspc->dma_mapped)
> +		return;

blank line

> +	dma_unmap_single(dev, sspc->rx_dma, sspc->len, PCI_DMA_FROMDEVICE);
> +	dma_unmap_single(dev, sspc->tx_dma, sspc->len, PCI_DMA_TODEVICE);
> +	sspc->dma_mapped = 0;

you shouldn't need this dma_mapped flag here...

> +static void ssp_spi_dma_done(void *arg)
> +{
> +	struct callback_param *cb_param = (struct callback_param *)arg;
> +	struct ssp_drv_context *sspc = cb_param->drv_context;
> +	struct device *dev = &sspc->pdev->dev;
> +	void *reg = sspc->ioaddr;
> +
> +	if (cb_param->direction == TX_DIRECTION)
> +		sspc->txdma_done = 1;
> +	else
> +		sspc->rxdma_done = 1;
> +
> +	dev_dbg(dev, "DMA callback for direction %d [RX done:%d] [TX done:%d]\n",
> +		cb_param->direction, sspc->rxdma_done,
> +		sspc->txdma_done);
> +
> +	if (sspc->txdma_done && sspc->rxdma_done) {
> +		/* Clear Status Register */
> +		write_SSSR(sspc->clear_sr, reg);
> +		dev_dbg(dev, "DMA done\n");
> +		/* Disable Triggers to DMA or to CPU*/
> +		disable_triggers(sspc);
> +		unmap_dma_buffers(sspc);
> +
> +		queue_work(sspc->dma_wq, &sspc->complete_work);

I fail to see the need for this workstruct, why can't you call
complete() directly ?

> +static irqreturn_t ssp_int(int irq, void *dev_id)
> +{
> +	struct ssp_drv_context *sspc = dev_id;
> +	void *reg = sspc->ioaddr;
> +	struct device *dev = &sspc->pdev->dev;
> +	u32 status = read_SSSR(reg);
> +
> +	/* It should never be our interrupt since SSP will */
> +	/* only trigs interrupt for under/over run.        */

wrong comment style

> +	if (likely(!(status & sspc->mask_sr)))
> +		return IRQ_NONE;
> +
> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
> +		WARN_ON(1);
> +		if (status & SSSR_ROR)
> +			dev_err(dev, "we have Overrun\n");
> +		if (status & SSSR_TUR)
> +			dev_err(dev, "we have Underrun\n");
> +	}

I would split these two caes here:

if (status & ROR)
	dev_WARN(dev, "Overrun\n");

if (status & TUR)
	dev_WARN(dev, "Underrun\n");

no need for nested ifs.

> +static void poll_transfer(unsigned long data)
> +{
> +	struct ssp_drv_context *sspc = (void *)data;
> +
> +	if (sspc->tx) {
> +		while (sspc->tx != sspc->tx_end) {
> +			if (ssp_timing_wr) {
> +				int timeout = 100;
> +				/* It is used as debug UART on Tangier. Since
> +				   baud rate = 115200, it needs at least 312us
> +				   for one word transferring. Becuase of silicon
> +				   issue, it MUST check SFIFOL here instead of
> +				   TNF. It is the workaround for A0 stepping*/

wrong comment style.

> +				while (--timeout &&
> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
> +					udelay(10);
> +			}
> +			sspc->write(sspc);
> +			sspc->read(sspc);
> +		}
> +	}

you can make this look sligthly better if you:

if (!sspc->tx)
	bail();

while (sspc->tx != sspc->tx_end) {
	if (sspc->timing_wr) {
		int timeout = 100;

		....
	}
}

it'll decrease one indentation level.

> +static void start_bitbanging(struct ssp_drv_context *sspc)

I would prefix with ssp_

> +static int handle_message(struct ssp_drv_context *sspc)
> +{
> +	struct chip_data *chip = NULL;
> +	struct spi_transfer *transfer = NULL;
> +	void *reg = sspc->ioaddr;
> +	u32 cr1;
> +	struct device *dev = &sspc->pdev->dev;
> +	struct spi_message *msg = sspc->cur_msg;
> +
> +	chip = spi_get_ctldata(msg->spi);
> +
> +	/* We handle only one transfer message since the protocol module has to
> +	   control the out of band signaling. */

wrong comment style.

> +	transfer = list_entry(msg->transfers.next, struct spi_transfer,
> +					transfer_list);
> +
> +	/* Check transfer length */
> +	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
> +		(transfer->len == 0))) {
> +		dev_warn(dev, "transfer length null or greater than %d\n",
> +			MAX_SPI_TRANSFER_SIZE);
> +		dev_warn(dev, "length = %d\n", transfer->len);
> +		msg->status = -EINVAL;
> +
> +		if (msg->complete)
> +			msg->complete(msg->context);
> +		complete(&sspc->msg_done);
> +		return 0;
> +	}
> +
> +	/* Flush any remaining data (in case of failed previous transfer) */
> +	flush(sspc);
> +
> +	sspc->tx  = (void *)transfer->tx_buf;
> +	sspc->rx  = (void *)transfer->rx_buf;
> +	sspc->len = transfer->len;
> +	sspc->write = chip->write;
> +	sspc->read = chip->read;
> +
> +	if (likely(chip->dma_enabled)) {
> +		sspc->dma_mapped = map_dma_buffers(sspc);
> +		if (unlikely(!sspc->dma_mapped))
> +			return 0;
> +	} else {
> +		sspc->write = sspc->tx ? chip->write : null_writer;
> +		sspc->read  = sspc->rx ? chip->read : null_reader;
> +	}
> +	sspc->tx_end = sspc->tx + transfer->len;
> +	sspc->rx_end = sspc->rx + transfer->len;
> +	write_SSSR(sspc->clear_sr, reg);
> +
> +	/* setup the CR1 control register */
> +	cr1 = chip->cr1 | sspc->cr1_sig;
> +
> +	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
> +		/* in case of len smaller than burst size, adjust the RX     */
> +		/* threshold. All other cases will use the default threshold */
> +		/* value. The RX fifo threshold must be aligned with the DMA */
> +		/* RX transfer size, which may be limited to a multiple of 4 */
> +		/* bytes due to 32bits DDR access.                           */

wrong comment style

> +static int ssp_spi_probe(struct pci_dev *pdev,
> +	const struct pci_device_id *ent)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct spi_master *master;
> +	struct ssp_drv_context *sspc = 0;
> +	int status;
> +	u32 iolen = 0;
> +	u8 ssp_cfg;
> +	int pos;
> +	void __iomem *syscfg_ioaddr;
> +	unsigned long syscfg;
> +
> +	/* Check if the SSP we are probed for has been allocated */
> +	/* to operate as SPI. This information is retreived from */
> +	/* the field adid of the Vendor-Specific PCI capability  */
> +	/* which is used as a configuration register.            */

wrong comment style

> +static int ssp_spi_runtime_suspend(struct device *dev)
> +{
> +	return 0;
> +}
> +
> +static int ssp_spi_runtime_resume(struct device *dev)
> +{
> +	return 0;
> +}

why even add these if they're no-ops ?

> +static int __init ssp_spi_init(void)
> +{
> +	return pci_register_driver(&ssp_spi_driver);
> +}
> +
> +late_initcall(ssp_spi_init);

does it have to be late ? Can't you just use module_pci_driver()
instead ?

> @@ -0,0 +1,330 @@
> +/*
> + *  Copyright (C) Intel 2013
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.

companies usually don't like this "at your option any later version"
statement. Usually it's GPL2 only...

-- 
balbi

[-- Attachment #2: Digital signature --]
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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:31   ` Felipe Balbi
  0 siblings, 0 replies; 36+ messages in thread
From: Felipe Balbi @ 2013-10-29 18:31 UTC (permalink / raw)
  To: David Cohen
  Cc: broonie-DgEjT+Ai2ygdnm+yROfE0A, ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

[-- Attachment #1: Type: text/plain, Size: 14869 bytes --]

Hi,

On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
> new file mode 100644
> index 0000000..b3b9fe8
> --- /dev/null
> +++ b/drivers/spi/spi-intel-mid-ssp.c
> @@ -0,0 +1,1506 @@
> +/*
> + * spi-intel-mid-ssp.c
> + * This driver supports Bulverde SSP core used on Intel MID platforms
> + * It supports SSP of Moorestown & Medfield platforms and handles clock
> + * slave & master modes.
> + *
> + * Copyright (c) 2013, Intel Corporation.
> + * Contacts: Ning Li <ning.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> + *	     David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> + *
> + */
> +
> +/*
> + * Note:
> + *
> + * Supports DMA and non-interrupt polled transfers.
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/highmem.h>
> +#include <linux/pci.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/intel_mid_dma.h>
> +#include <linux/pm_qos.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/completion.h>
> +#include <asm/intel-mid.h>
> +
> +#include <linux/spi/spi.h>
> +#include <linux/spi/intel_mid_ssp_spi.h>
> +
> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
> +
> +static int ssp_timing_wr;

this will prevent multiple instances of the same driver.

> +#ifdef DUMP_RX
> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
> +{
> +	int tlen1 = (len < sz ? len : sz);
> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
> +	unsigned char *p;
> +	static char msg[MAX_SPI_TRANSFER_SIZE];
> +
> +	memset(msg, '\0', sizeof(msg));
> +	p = buf;
> +	while (p < buf + tlen1)
> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +
> +	if (tlen2 > 0) {
> +		sprintf(msg, "%s .....", msg);
> +		p = (buf+len) - tlen2;
> +		while (p < buf + len)
> +			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> +	}
> +
> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
> +		   len-tlen2, len - 1, msg);
> +}
> +#endif

either move this to debugfs or stub the function out ifndef DUMP_RX,
then you don't need the ifdefs when calling it.

> +static inline u8 ssp_cfg_get_mode(u8 ssp_cfg)
> +{
> +	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)

instead, couldn't you use driver data to pass some flags to the driver ?
I can't see intel_mid_identify_cpu and having drivers depend on
arch-specific code is usually a bad practice.

> +		return (ssp_cfg) & 0x03;
> +	else

else isn't needed here

> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +	u32 sssr;

blank line here would aid readability

> +	sssr = read_SSSR(sspc->ioaddr);
> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
> +		return 0;
> +	else

else isn't necessary

> +static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +	return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);

you don't need the outter parenthesis here, GCC should've warned you,
even.

> +static inline void disable_interface(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line here

> +	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
> +}
> +
> +static inline void disable_triggers(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

and here...

> +	write_SSCR1(read_SSCR1(reg) & ~sspc->cr1_sig, reg);
> +}
> +
> +
> +static void flush(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	u32 i = 0;
> +
> +	/* If the transmit fifo is not empty, reset the interface. */
> +	if (!is_tx_fifo_empty(sspc)) {
> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
> +		disable_interface(sspc);
> +		return;
> +	}

not so sure, if the transmit fifo isn't empty and you reset it, you
could end up corrupting data which is about to be shifted into the wire,
couldn't you ?

Is this a case which would *really* happen in normal conditions ? If so,
why ?

> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
> +		read_SSDR(reg);
> +		i++;
> +	}
> +	WARN(i > 0, "%d words flush occured\n", i);

similarly, you could be ignoring data you *should* indeed be handling.

> +
> +	return;

return statement is unnecessary.

> +static int null_writer(struct ssp_drv_context *sspc)

looks like these two functions (null_\(writer\|reader\)) need some
documentation. Why do they exist ?

> +static int u8_writer(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> +		|| (sspc->tx == sspc->tx_end))
> +		return 0;
> +
> +	write_SSDR(*(u8 *)(sspc->tx), reg);
> +	++sspc->tx;
> +
> +	return 1;
> +}
> +
> +static int u8_reader(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	while ((read_SSSR(reg) & SSSR_RNE)
> +		&& (sspc->rx < sspc->rx_end)) {
> +		*(u8 *)(sspc->rx) = read_SSDR(reg);
> +		++sspc->rx;
> +	}
> +
> +	return sspc->rx == sspc->rx_end;
> +}
> +
> +static int u16_writer(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)

the extra comparisson here is superfluous.

> +		|| (sspc->tx == sspc->tx_end))
> +		return 0;
> +
> +	write_SSDR(*(u16 *)(sspc->tx), reg);
> +	sspc->tx += 2;
> +
> +	return 1;
> +}
> +
> +static int u16_reader(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
> +		*(u16 *)(sspc->rx) = read_SSDR(reg);
> +		sspc->rx += 2;
> +	}
> +
> +	return sspc->rx == sspc->rx_end;
> +}
> +
> +static int u32_writer(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)

the extra comparisson here is superfluous.

> +		|| (sspc->tx == sspc->tx_end))
> +		return 0;
> +
> +	write_SSDR(*(u32 *)(sspc->tx), reg);
> +	sspc->tx += 4;
> +
> +	return 1;
> +}
> +
> +static int u32_reader(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;

blank line

> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
> +		*(u32 *)(sspc->rx) = read_SSDR(reg);
> +		sspc->rx += 4;
> +	}
> +
> +	return sspc->rx == sspc->rx_end;
> +}
> +
> +static bool chan_filter(struct dma_chan *chan, void *param)
> +{
> +	struct ssp_drv_context *sspc = param;
> +
> +	if (sspc->dmac1 && chan->device->dev == &sspc->dmac1->dev)
> +		return true;
> +
> +	return false;
> +}
> +
> +/**
> + * unmap_dma_buffers() - Unmap the DMA buffers used during the last transfer.
> + * @sspc:	Pointer to the private driver context
> + */
> +static void unmap_dma_buffers(struct ssp_drv_context *sspc)
> +{
> +	struct device *dev = &sspc->pdev->dev;
> +
> +	if (!sspc->dma_mapped)
> +		return;

blank line

> +	dma_unmap_single(dev, sspc->rx_dma, sspc->len, PCI_DMA_FROMDEVICE);
> +	dma_unmap_single(dev, sspc->tx_dma, sspc->len, PCI_DMA_TODEVICE);
> +	sspc->dma_mapped = 0;

you shouldn't need this dma_mapped flag here...

> +static void ssp_spi_dma_done(void *arg)
> +{
> +	struct callback_param *cb_param = (struct callback_param *)arg;
> +	struct ssp_drv_context *sspc = cb_param->drv_context;
> +	struct device *dev = &sspc->pdev->dev;
> +	void *reg = sspc->ioaddr;
> +
> +	if (cb_param->direction == TX_DIRECTION)
> +		sspc->txdma_done = 1;
> +	else
> +		sspc->rxdma_done = 1;
> +
> +	dev_dbg(dev, "DMA callback for direction %d [RX done:%d] [TX done:%d]\n",
> +		cb_param->direction, sspc->rxdma_done,
> +		sspc->txdma_done);
> +
> +	if (sspc->txdma_done && sspc->rxdma_done) {
> +		/* Clear Status Register */
> +		write_SSSR(sspc->clear_sr, reg);
> +		dev_dbg(dev, "DMA done\n");
> +		/* Disable Triggers to DMA or to CPU*/
> +		disable_triggers(sspc);
> +		unmap_dma_buffers(sspc);
> +
> +		queue_work(sspc->dma_wq, &sspc->complete_work);

I fail to see the need for this workstruct, why can't you call
complete() directly ?

> +static irqreturn_t ssp_int(int irq, void *dev_id)
> +{
> +	struct ssp_drv_context *sspc = dev_id;
> +	void *reg = sspc->ioaddr;
> +	struct device *dev = &sspc->pdev->dev;
> +	u32 status = read_SSSR(reg);
> +
> +	/* It should never be our interrupt since SSP will */
> +	/* only trigs interrupt for under/over run.        */

wrong comment style

> +	if (likely(!(status & sspc->mask_sr)))
> +		return IRQ_NONE;
> +
> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
> +		WARN_ON(1);
> +		if (status & SSSR_ROR)
> +			dev_err(dev, "we have Overrun\n");
> +		if (status & SSSR_TUR)
> +			dev_err(dev, "we have Underrun\n");
> +	}

I would split these two caes here:

if (status & ROR)
	dev_WARN(dev, "Overrun\n");

if (status & TUR)
	dev_WARN(dev, "Underrun\n");

no need for nested ifs.

> +static void poll_transfer(unsigned long data)
> +{
> +	struct ssp_drv_context *sspc = (void *)data;
> +
> +	if (sspc->tx) {
> +		while (sspc->tx != sspc->tx_end) {
> +			if (ssp_timing_wr) {
> +				int timeout = 100;
> +				/* It is used as debug UART on Tangier. Since
> +				   baud rate = 115200, it needs at least 312us
> +				   for one word transferring. Becuase of silicon
> +				   issue, it MUST check SFIFOL here instead of
> +				   TNF. It is the workaround for A0 stepping*/

wrong comment style.

> +				while (--timeout &&
> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
> +					udelay(10);
> +			}
> +			sspc->write(sspc);
> +			sspc->read(sspc);
> +		}
> +	}

you can make this look sligthly better if you:

if (!sspc->tx)
	bail();

while (sspc->tx != sspc->tx_end) {
	if (sspc->timing_wr) {
		int timeout = 100;

		....
	}
}

it'll decrease one indentation level.

> +static void start_bitbanging(struct ssp_drv_context *sspc)

I would prefix with ssp_

> +static int handle_message(struct ssp_drv_context *sspc)
> +{
> +	struct chip_data *chip = NULL;
> +	struct spi_transfer *transfer = NULL;
> +	void *reg = sspc->ioaddr;
> +	u32 cr1;
> +	struct device *dev = &sspc->pdev->dev;
> +	struct spi_message *msg = sspc->cur_msg;
> +
> +	chip = spi_get_ctldata(msg->spi);
> +
> +	/* We handle only one transfer message since the protocol module has to
> +	   control the out of band signaling. */

wrong comment style.

> +	transfer = list_entry(msg->transfers.next, struct spi_transfer,
> +					transfer_list);
> +
> +	/* Check transfer length */
> +	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
> +		(transfer->len == 0))) {
> +		dev_warn(dev, "transfer length null or greater than %d\n",
> +			MAX_SPI_TRANSFER_SIZE);
> +		dev_warn(dev, "length = %d\n", transfer->len);
> +		msg->status = -EINVAL;
> +
> +		if (msg->complete)
> +			msg->complete(msg->context);
> +		complete(&sspc->msg_done);
> +		return 0;
> +	}
> +
> +	/* Flush any remaining data (in case of failed previous transfer) */
> +	flush(sspc);
> +
> +	sspc->tx  = (void *)transfer->tx_buf;
> +	sspc->rx  = (void *)transfer->rx_buf;
> +	sspc->len = transfer->len;
> +	sspc->write = chip->write;
> +	sspc->read = chip->read;
> +
> +	if (likely(chip->dma_enabled)) {
> +		sspc->dma_mapped = map_dma_buffers(sspc);
> +		if (unlikely(!sspc->dma_mapped))
> +			return 0;
> +	} else {
> +		sspc->write = sspc->tx ? chip->write : null_writer;
> +		sspc->read  = sspc->rx ? chip->read : null_reader;
> +	}
> +	sspc->tx_end = sspc->tx + transfer->len;
> +	sspc->rx_end = sspc->rx + transfer->len;
> +	write_SSSR(sspc->clear_sr, reg);
> +
> +	/* setup the CR1 control register */
> +	cr1 = chip->cr1 | sspc->cr1_sig;
> +
> +	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
> +		/* in case of len smaller than burst size, adjust the RX     */
> +		/* threshold. All other cases will use the default threshold */
> +		/* value. The RX fifo threshold must be aligned with the DMA */
> +		/* RX transfer size, which may be limited to a multiple of 4 */
> +		/* bytes due to 32bits DDR access.                           */

wrong comment style

> +static int ssp_spi_probe(struct pci_dev *pdev,
> +	const struct pci_device_id *ent)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct spi_master *master;
> +	struct ssp_drv_context *sspc = 0;
> +	int status;
> +	u32 iolen = 0;
> +	u8 ssp_cfg;
> +	int pos;
> +	void __iomem *syscfg_ioaddr;
> +	unsigned long syscfg;
> +
> +	/* Check if the SSP we are probed for has been allocated */
> +	/* to operate as SPI. This information is retreived from */
> +	/* the field adid of the Vendor-Specific PCI capability  */
> +	/* which is used as a configuration register.            */

wrong comment style

> +static int ssp_spi_runtime_suspend(struct device *dev)
> +{
> +	return 0;
> +}
> +
> +static int ssp_spi_runtime_resume(struct device *dev)
> +{
> +	return 0;
> +}

why even add these if they're no-ops ?

> +static int __init ssp_spi_init(void)
> +{
> +	return pci_register_driver(&ssp_spi_driver);
> +}
> +
> +late_initcall(ssp_spi_init);

does it have to be late ? Can't you just use module_pci_driver()
instead ?

> @@ -0,0 +1,330 @@
> +/*
> + *  Copyright (C) Intel 2013
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; either version 2 of the License, or
> + *  (at your option) any later version.

companies usually don't like this "at your option any later version"
statement. Usually it's GPL2 only...

-- 
balbi

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 2/2] MAINTAINERS: add Intel MID SSP SPI maintainers
  2013-10-29 18:20   ` Joe Perches
@ 2013-10-29 18:33       ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:33 UTC (permalink / raw)
  To: Joe Perches; +Cc: broonie, ning.li, linux-kernel, linux-spi

On 10/29/2013 11:20 AM, Joe Perches wrote:
> On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
> []
>> diff --git a/MAINTAINERS b/MAINTAINERS
> []
>> @@ -1916,6 +1916,14 @@ L:	linux-gpio@vger.kernel.org
>>   S:	Maintained
>>   F:	drivers/gpio/gpio-intel-mid.c
>
> Please insert this section in alphabetic order.

It supposed to be. But this patch got messed up with another one.
I'll fix it.

>
>> +INTEL-MID SSP SPI DRIVER
>> +M:	Ning Li <ning.li@intel.com>
>> +M:	David Cohen <david.a.cohen@linux.intel.com>
>> +L:	linux-spi@vger.kernel.org
>> +S:	Maintained
>
> Supported?

Supported from my side but maintained on Ning Li's.
But I can change to supported.

Thanks,

David Cohen

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 2/2] MAINTAINERS: add Intel MID SSP SPI maintainers
@ 2013-10-29 18:33       ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:33 UTC (permalink / raw)
  To: Joe Perches
  Cc: broonie-DgEjT+Ai2ygdnm+yROfE0A, ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA

On 10/29/2013 11:20 AM, Joe Perches wrote:
> On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
> []
>> diff --git a/MAINTAINERS b/MAINTAINERS
> []
>> @@ -1916,6 +1916,14 @@ L:	linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>>   S:	Maintained
>>   F:	drivers/gpio/gpio-intel-mid.c
>
> Please insert this section in alphabetic order.

It supposed to be. But this patch got messed up with another one.
I'll fix it.

>
>> +INTEL-MID SSP SPI DRIVER
>> +M:	Ning Li <ning.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>> +M:	David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
>> +L:	linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> +S:	Maintained
>
> Supported?

Supported from my side but maintained on Ning Li's.
But I can change to supported.

Thanks,

David Cohen
--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:35     ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:35 UTC (permalink / raw)
  To: Randy Dunlap; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

Hi Randy,

On 10/29/2013 11:29 AM, Randy Dunlap wrote:
> Hi,
> Here are a few comments for your next version.

Ack for all of your comments. I'll consider them on next version.

Br, David Cohen

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:35     ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 18:35 UTC (permalink / raw)
  To: Randy Dunlap
  Cc: broonie-DgEjT+Ai2ygdnm+yROfE0A, ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

Hi Randy,

On 10/29/2013 11:29 AM, Randy Dunlap wrote:
> Hi,
> Here are a few comments for your next version.

Ack for all of your comments. I'll consider them on next version.

Br, David Cohen
--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:35       ` Joe Perches
  0 siblings, 0 replies; 36+ messages in thread
From: Joe Perches @ 2013-10-29 18:35 UTC (permalink / raw)
  To: David Cohen; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

On Tue, 2013-10-29 at 11:30 -0700, David Cohen wrote:
> Hi Joe,
> 
> On 10/29/2013 11:19 AM, Joe Perches wrote:
> > On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
> >> This patch adds driver for ssp spi interface on Intel Mid platform.
> >
> > A few simple notes:
> >
> > Please consider using checkpatch.
> 
> I did and got no warnings. But haven't used --strict option.

Interesting.  I thought there was a return (foo);
statement that should have been marked, but I didn't
actually run checkpatch.

static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
+{
+       return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
+}

This could be bool too



^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:35       ` Joe Perches
  0 siblings, 0 replies; 36+ messages in thread
From: Joe Perches @ 2013-10-29 18:35 UTC (permalink / raw)
  To: David Cohen
  Cc: broonie-DgEjT+Ai2ygdnm+yROfE0A, ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

On Tue, 2013-10-29 at 11:30 -0700, David Cohen wrote:
> Hi Joe,
> 
> On 10/29/2013 11:19 AM, Joe Perches wrote:
> > On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
> >> This patch adds driver for ssp spi interface on Intel Mid platform.
> >
> > A few simple notes:
> >
> > Please consider using checkpatch.
> 
> I did and got no warnings. But haven't used --strict option.

Interesting.  I thought there was a return (foo);
statement that should have been marked, but I didn't
actually run checkpatch.

static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
+{
+       return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
+}

This could be bool too


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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:56   ` Mark Brown
  0 siblings, 0 replies; 36+ messages in thread
From: Mark Brown @ 2013-10-29 18:56 UTC (permalink / raw)
  To: David Cohen; +Cc: ning.li, linux-kernel, linux-spi, Fei Yang

[-- Attachment #1: Type: text/plain, Size: 7057 bytes --]

On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
> From: Fei Yang <fei.yang@intel.com>
> 
> This patch adds driver for ssp spi interface on Intel Mid platform.

Is there not any possibility of code sharing with the PXA SSP IP?  It
seems odd that Intel would make a second IP of the same name that's
totally incompatible...  not looked at the register interfaces in detail
but the register names certainly look familiar.

> +	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
> +	depends on X86_INTEL_MID && SPI_MASTER && INTEL_MID_DMAC
> +	help

Are these all build time dependencies?  There's certainly no need to
depend on SPI_MASTER, all drivers are inside an if SPI_MASTER block.

> +static int ssp_timing_wr;

Why is this a static global?

> +#ifdef DUMP_RX
> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
> +{

Please add this support as a standard feature of the SPI core if it's
useful, there's nothing specific to this driver in it.  Using trace
would probably be better than dumping to the console.

> +	static char msg[MAX_SPI_TRANSFER_SIZE];

Where did that limit come from?

> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +	u32 sssr;
> +	sssr = read_SSSR(sspc->ioaddr);
> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)

This looks odd, why not sssr & (SSSR_TFL_MASK | SSSR_TNF)?

> +static void flush(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	u32 i = 0;
> +
> +	/* If the transmit fifo is not empty, reset the interface. */
> +	if (!is_tx_fifo_empty(sspc)) {
> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
> +		disable_interface(sspc);
> +		return;
> +	}

This isn't a flush then?

> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));

No extra space at the start of the message and why is there a \r in
there?  Throughout the driver your log messages have a range of odd
formatting quirks that aren't consistent and don't look like normal
Linux log messages either.

Please also check the severity of your messages, many of them seem too
loud.

> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
> +		read_SSDR(reg);
> +		i++;
> +	}

What happens if the FIFO doesn't drain?

> +	WARN(i > 0, "%d words flush occured\n", i);

This seems *very* loud for a flush operation...

> +	if (sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY) {
> +		sspc->virt_addr_sram_rx = ioremap_nocache(SRAM_BASE_ADDR,
> +				2 * MAX_SPI_TRANSFER_SIZE);

This doesn't look terribly clever, it's remapping a hard coded address
rather than getting the address enumerated from a device enumeration
interface.

> +	/* get Data Read/Write address */
> +	ssdr_addr = (dma_addr_t)(sspc->paddr + 0x10);

I'm not entirely sure what this does but it looks dodgy...  what's the
cast doing for a start?

> +		/* In Rx direction, TRAIL Bytes are handled by memcpy */

Please don't randomly CAPITALISE words.

> +	rxdesc = rxchan->device->device_prep_dma_memcpy
> +		(rxchan,			/* DMA Channel */
> +		sspc->rx_dma,			/* DAR */
> +		ssdr_addr,			/* SAR */
> +		sspc->len_dma_rx,		/* Data Length */
> +		flag);					/* Flag */

What's going on here?  Why is there a DMAed memcpy()?  This doesn't
reflect normal DMA usage in SPI drivers at all, I'd expect to see
dmaengine_prep_ being used.

> +static void int_transfer_complete(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	struct spi_message *msg;
> +	struct device *dev = &sspc->pdev->dev;
> +
> +	if (unlikely(sspc->quirks & QUIRKS_USE_PM_QOS))
> +		pm_qos_update_request(&sspc->pm_qos_req,
> +					PM_QOS_DEFAULT_VALUE);

Why is this a quirk and not abstracted away by the PM QoS API on
platforms that don't need it?  I'd also expect these updates to be done
in runtime PM callbacks so that if two transfers follow one another we
don't bounce the Qos up and down.

> +	dev_dbg(dev, "End of transfer. SSSR:%08X\n", read_SSSR(reg));
> +	msg = sspc->cur_msg;
> +	if (likely(msg->complete))
> +		msg->complete(msg->context);
> +	complete(&sspc->msg_done);

Remove all these likely()s, they're making the code less clear and seem
vanishingly unlikely to have any practical impact on performance.

> +static void int_transfer_complete_work(struct work_struct *work)
> +{
> +	struct ssp_drv_context *sspc = container_of(work,
> +				struct ssp_drv_context, complete_work);
> +
> +	int_transfer_complete(sspc);
> +}

This wrapper function doesn't seem terribly useful...  why not just
inline it into the internal function?

> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
> +		WARN_ON(1);
> +		if (status & SSSR_ROR)
> +			dev_err(dev, "we have Overrun\n");
> +		if (status & SSSR_TUR)
> +			dev_err(dev, "we have Underrun\n");
> +	}
> +
> +	/* We can fall here when not using DMA mode */
> +	if (!sspc->cur_msg) {
> +		disable_interface(sspc);
> +		disable_triggers(sspc);
> +	}
> +	/* clear status register */
> +	write_SSSR(sspc->clear_sr, reg);

More comments explaining what's going on here would be good...

> +static void poll_transfer(unsigned long data)
> +{
> +	struct ssp_drv_context *sspc = (void *)data;
> +
> +	if (sspc->tx) {
> +		while (sspc->tx != sspc->tx_end) {
> +			if (ssp_timing_wr) {
> +				int timeout = 100;
> +				/* It is used as debug UART on Tangier. Since
> +				   baud rate = 115200, it needs at least 312us
> +				   for one word transferring. Becuase of silicon
> +				   issue, it MUST check SFIFOL here instead of
> +				   TNF. It is the workaround for A0 stepping*/
> +				while (--timeout &&
> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
> +					udelay(10);
> +			}

This doesn't look like it shouldn't be here at all or should be made
more generic but I can't really tell what it's supposed to do...

> +static void start_bitbanging(struct ssp_drv_context *sspc)
> +{

The SPI core has bitbanging helpers which you don't seem to be using.
However...

> +	/* Bit bang the clock until CSS clears */
> +	while ((sssr & 0x400000) && (count < MAX_BITBANGING_LOOP)) {
> +		write_I2CDATA(0x2, i2c_reg);
> +		udelay(I2C_ACCESS_USDELAY);

...this code is talking about I2C?

> +		udelay(I2C_ACCESS_USDELAY);
> +		write_I2CCTRL(0x01070034, i2c_reg);

This appears to be randomly bashing on an absolute register address.

> +/**
> + * transfer() - Start a SPI transfer
> + * @spi:	Pointer to the spi_device struct
> + * @msg:	Pointer to the spi_message struct
> + */
> +static int transfer(struct spi_device *spi, struct spi_message *msg)

Use of plain transfer() has been deprecated since v3.4, you should at
least be using transfer_one_message().  I've stopped reviewing at this
point since a lot of the rest of the code is replicating stuff that's in
the SPI core and will go away when you update to use the current APIs.

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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 18:56   ` Mark Brown
  0 siblings, 0 replies; 36+ messages in thread
From: Mark Brown @ 2013-10-29 18:56 UTC (permalink / raw)
  To: David Cohen
  Cc: ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

[-- Attachment #1: Type: text/plain, Size: 7087 bytes --]

On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
> From: Fei Yang <fei.yang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> 
> This patch adds driver for ssp spi interface on Intel Mid platform.

Is there not any possibility of code sharing with the PXA SSP IP?  It
seems odd that Intel would make a second IP of the same name that's
totally incompatible...  not looked at the register interfaces in detail
but the register names certainly look familiar.

> +	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
> +	depends on X86_INTEL_MID && SPI_MASTER && INTEL_MID_DMAC
> +	help

Are these all build time dependencies?  There's certainly no need to
depend on SPI_MASTER, all drivers are inside an if SPI_MASTER block.

> +static int ssp_timing_wr;

Why is this a static global?

> +#ifdef DUMP_RX
> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
> +{

Please add this support as a standard feature of the SPI core if it's
useful, there's nothing specific to this driver in it.  Using trace
would probably be better than dumping to the console.

> +	static char msg[MAX_SPI_TRANSFER_SIZE];

Where did that limit come from?

> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +	u32 sssr;
> +	sssr = read_SSSR(sspc->ioaddr);
> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)

This looks odd, why not sssr & (SSSR_TFL_MASK | SSSR_TNF)?

> +static void flush(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	u32 i = 0;
> +
> +	/* If the transmit fifo is not empty, reset the interface. */
> +	if (!is_tx_fifo_empty(sspc)) {
> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
> +		disable_interface(sspc);
> +		return;
> +	}

This isn't a flush then?

> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));

No extra space at the start of the message and why is there a \r in
there?  Throughout the driver your log messages have a range of odd
formatting quirks that aren't consistent and don't look like normal
Linux log messages either.

Please also check the severity of your messages, many of them seem too
loud.

> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
> +		read_SSDR(reg);
> +		i++;
> +	}

What happens if the FIFO doesn't drain?

> +	WARN(i > 0, "%d words flush occured\n", i);

This seems *very* loud for a flush operation...

> +	if (sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY) {
> +		sspc->virt_addr_sram_rx = ioremap_nocache(SRAM_BASE_ADDR,
> +				2 * MAX_SPI_TRANSFER_SIZE);

This doesn't look terribly clever, it's remapping a hard coded address
rather than getting the address enumerated from a device enumeration
interface.

> +	/* get Data Read/Write address */
> +	ssdr_addr = (dma_addr_t)(sspc->paddr + 0x10);

I'm not entirely sure what this does but it looks dodgy...  what's the
cast doing for a start?

> +		/* In Rx direction, TRAIL Bytes are handled by memcpy */

Please don't randomly CAPITALISE words.

> +	rxdesc = rxchan->device->device_prep_dma_memcpy
> +		(rxchan,			/* DMA Channel */
> +		sspc->rx_dma,			/* DAR */
> +		ssdr_addr,			/* SAR */
> +		sspc->len_dma_rx,		/* Data Length */
> +		flag);					/* Flag */

What's going on here?  Why is there a DMAed memcpy()?  This doesn't
reflect normal DMA usage in SPI drivers at all, I'd expect to see
dmaengine_prep_ being used.

> +static void int_transfer_complete(struct ssp_drv_context *sspc)
> +{
> +	void *reg = sspc->ioaddr;
> +	struct spi_message *msg;
> +	struct device *dev = &sspc->pdev->dev;
> +
> +	if (unlikely(sspc->quirks & QUIRKS_USE_PM_QOS))
> +		pm_qos_update_request(&sspc->pm_qos_req,
> +					PM_QOS_DEFAULT_VALUE);

Why is this a quirk and not abstracted away by the PM QoS API on
platforms that don't need it?  I'd also expect these updates to be done
in runtime PM callbacks so that if two transfers follow one another we
don't bounce the Qos up and down.

> +	dev_dbg(dev, "End of transfer. SSSR:%08X\n", read_SSSR(reg));
> +	msg = sspc->cur_msg;
> +	if (likely(msg->complete))
> +		msg->complete(msg->context);
> +	complete(&sspc->msg_done);

Remove all these likely()s, they're making the code less clear and seem
vanishingly unlikely to have any practical impact on performance.

> +static void int_transfer_complete_work(struct work_struct *work)
> +{
> +	struct ssp_drv_context *sspc = container_of(work,
> +				struct ssp_drv_context, complete_work);
> +
> +	int_transfer_complete(sspc);
> +}

This wrapper function doesn't seem terribly useful...  why not just
inline it into the internal function?

> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
> +		WARN_ON(1);
> +		if (status & SSSR_ROR)
> +			dev_err(dev, "we have Overrun\n");
> +		if (status & SSSR_TUR)
> +			dev_err(dev, "we have Underrun\n");
> +	}
> +
> +	/* We can fall here when not using DMA mode */
> +	if (!sspc->cur_msg) {
> +		disable_interface(sspc);
> +		disable_triggers(sspc);
> +	}
> +	/* clear status register */
> +	write_SSSR(sspc->clear_sr, reg);

More comments explaining what's going on here would be good...

> +static void poll_transfer(unsigned long data)
> +{
> +	struct ssp_drv_context *sspc = (void *)data;
> +
> +	if (sspc->tx) {
> +		while (sspc->tx != sspc->tx_end) {
> +			if (ssp_timing_wr) {
> +				int timeout = 100;
> +				/* It is used as debug UART on Tangier. Since
> +				   baud rate = 115200, it needs at least 312us
> +				   for one word transferring. Becuase of silicon
> +				   issue, it MUST check SFIFOL here instead of
> +				   TNF. It is the workaround for A0 stepping*/
> +				while (--timeout &&
> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
> +					udelay(10);
> +			}

This doesn't look like it shouldn't be here at all or should be made
more generic but I can't really tell what it's supposed to do...

> +static void start_bitbanging(struct ssp_drv_context *sspc)
> +{

The SPI core has bitbanging helpers which you don't seem to be using.
However...

> +	/* Bit bang the clock until CSS clears */
> +	while ((sssr & 0x400000) && (count < MAX_BITBANGING_LOOP)) {
> +		write_I2CDATA(0x2, i2c_reg);
> +		udelay(I2C_ACCESS_USDELAY);

...this code is talking about I2C?

> +		udelay(I2C_ACCESS_USDELAY);
> +		write_I2CCTRL(0x01070034, i2c_reg);

This appears to be randomly bashing on an absolute register address.

> +/**
> + * transfer() - Start a SPI transfer
> + * @spi:	Pointer to the spi_device struct
> + * @msg:	Pointer to the spi_message struct
> + */
> +static int transfer(struct spi_device *spi, struct spi_message *msg)

Use of plain transfer() has been deprecated since v3.4, you should at
least be using transfer_one_message().  I've stopped reviewing at this
point since a lot of the rest of the code is replicating stuff that's in
the SPI core and will go away when you update to use the current APIs.

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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 2/2] MAINTAINERS: add Intel MID SSP SPI maintainers
  2013-10-29 18:05   ` David Cohen
  (?)
  (?)
@ 2013-10-29 18:57   ` Mark Brown
  -1 siblings, 0 replies; 36+ messages in thread
From: Mark Brown @ 2013-10-29 18:57 UTC (permalink / raw)
  To: David Cohen; +Cc: ning.li, linux-kernel, linux-spi

[-- Attachment #1: Type: text/plain, Size: 205 bytes --]

On Tue, Oct 29, 2013 at 11:05:50AM -0700, David Cohen wrote:
> Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>

Don't send something like this as a separate patch, include it in the
main patch.

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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
  2013-10-29 18:35       ` Joe Perches
@ 2013-10-29 19:32         ` David Cohen
  -1 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 19:32 UTC (permalink / raw)
  To: Joe Perches; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

On 10/29/2013 11:35 AM, Joe Perches wrote:
> On Tue, 2013-10-29 at 11:30 -0700, David Cohen wrote:
>> Hi Joe,
>>
>> On 10/29/2013 11:19 AM, Joe Perches wrote:
>>> On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
>>>> This patch adds driver for ssp spi interface on Intel Mid platform.
>>>
>>> A few simple notes:
>>>
>>> Please consider using checkpatch.
>>
>> I did and got no warnings. But haven't used --strict option.
>
> Interesting.  I thought there was a return (foo);
> statement that should have been marked, but I didn't
> actually run checkpatch.

It seems odd checkpatch didn't catch it. I'll investigate.

>
> static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +       return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
> +}
>
> This could be bool too

u32 seems unusual, but I'd prefer 'int' if it's fine for you.

Br, David

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 19:32         ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 19:32 UTC (permalink / raw)
  To: Joe Perches
  Cc: broonie-DgEjT+Ai2ygdnm+yROfE0A, ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

On 10/29/2013 11:35 AM, Joe Perches wrote:
> On Tue, 2013-10-29 at 11:30 -0700, David Cohen wrote:
>> Hi Joe,
>>
>> On 10/29/2013 11:19 AM, Joe Perches wrote:
>>> On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
>>>> This patch adds driver for ssp spi interface on Intel Mid platform.
>>>
>>> A few simple notes:
>>>
>>> Please consider using checkpatch.
>>
>> I did and got no warnings. But haven't used --strict option.
>
> Interesting.  I thought there was a return (foo);
> statement that should have been marked, but I didn't
> actually run checkpatch.

It seems odd checkpatch didn't catch it. I'll investigate.

>
> static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> +{
> +       return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
> +}
>
> This could be bool too

u32 seems unusual, but I'd prefer 'int' if it's fine for you.

Br, David
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To unsubscribe from this list: send the line "unsubscribe linux-spi" in
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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 19:38           ` Joe Perches
  0 siblings, 0 replies; 36+ messages in thread
From: Joe Perches @ 2013-10-29 19:38 UTC (permalink / raw)
  To: David Cohen; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

On Tue, 2013-10-29 at 12:32 -0700, David Cohen wrote:
> On 10/29/2013 11:35 AM, Joe Perches wrote:
> > On Tue, 2013-10-29 at 11:30 -0700, David Cohen wrote:
> >> On 10/29/2013 11:19 AM, Joe Perches wrote:
> >>> On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
> >>>> This patch adds driver for ssp spi interface on Intel Mid platform.
> >>> A few simple notes:
> >>> Please consider using checkpatch.
> >> I did and got no warnings. But haven't used --strict option.
> > Interesting.  I thought there was a return (foo);
> > statement that should have been marked, but I didn't
> > actually run checkpatch.
> 
> It seems odd checkpatch didn't catch it. I'll investigate.

No need.  I believe I know why.
checkpatch doesn't use "$balanced_parens" checks for return
tests.  I'm not sure it's worth fixing right now, but it
could be tested as:

	if ($^V && $^V ge 5.10.0 &&
	    $stat =~ /^.\s*return\s*$balanced_parens\s*;\s*$/)

> > static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> > +{
> > +       return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
> > +}
> > This could be bool too
> u32 seems unusual, but I'd prefer 'int' if it's fine for you.

Anything is_<foo> that returns what seems to be true/false
I think could be bool.

But, no worries, it's your code.  Do what you think best.



^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 19:38           ` Joe Perches
  0 siblings, 0 replies; 36+ messages in thread
From: Joe Perches @ 2013-10-29 19:38 UTC (permalink / raw)
  To: David Cohen
  Cc: broonie-DgEjT+Ai2ygdnm+yROfE0A, ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

On Tue, 2013-10-29 at 12:32 -0700, David Cohen wrote:
> On 10/29/2013 11:35 AM, Joe Perches wrote:
> > On Tue, 2013-10-29 at 11:30 -0700, David Cohen wrote:
> >> On 10/29/2013 11:19 AM, Joe Perches wrote:
> >>> On Tue, 2013-10-29 at 11:05 -0700, David Cohen wrote:
> >>>> This patch adds driver for ssp spi interface on Intel Mid platform.
> >>> A few simple notes:
> >>> Please consider using checkpatch.
> >> I did and got no warnings. But haven't used --strict option.
> > Interesting.  I thought there was a return (foo);
> > statement that should have been marked, but I didn't
> > actually run checkpatch.
> 
> It seems odd checkpatch didn't catch it. I'll investigate.

No need.  I believe I know why.
checkpatch doesn't use "$balanced_parens" checks for return
tests.  I'm not sure it's worth fixing right now, but it
could be tested as:

	if ($^V && $^V ge 5.10.0 &&
	    $stat =~ /^.\s*return\s*$balanced_parens\s*;\s*$/)

> > static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> > +{
> > +       return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
> > +}
> > This could be bool too
> u32 seems unusual, but I'd prefer 'int' if it's fine for you.

Anything is_<foo> that returns what seems to be true/false
I think could be bool.

But, no worries, it's your code.  Do what you think best.


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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 20:08     ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 20:08 UTC (permalink / raw)
  To: Mark Brown; +Cc: ning.li, linux-kernel, linux-spi, Fei Yang

Hi Mark,

On 10/29/2013 11:56 AM, Mark Brown wrote:
> On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
>> From: Fei Yang <fei.yang@intel.com>
>>
>> This patch adds driver for ssp spi interface on Intel Mid platform.
>
> Is there not any possibility of code sharing with the PXA SSP IP?  It
> seems odd that Intel would make a second IP of the same name that's
> totally incompatible...  not looked at the register interfaces in detail
> but the register names certainly look familiar.

I need to bring this question to IO team (who wrote this driver)

>
>> +	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
>> +	depends on X86_INTEL_MID && SPI_MASTER && INTEL_MID_DMAC
>> +	help
>
> Are these all build time dependencies?  There's certainly no need to
> depend on SPI_MASTER, all drivers are inside an if SPI_MASTER block.
>
>> +static int ssp_timing_wr;
>
> Why is this a static global?

My only answer would be: because a lazy developer decided so :)

>
>> +#ifdef DUMP_RX
>> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
>> +{
>
> Please add this support as a standard feature of the SPI core if it's
> useful, there's nothing specific to this driver in it.  Using trace
> would probably be better than dumping to the console.

Agreed.

>
>> +	static char msg[MAX_SPI_TRANSFER_SIZE];
>
> Where did that limit come from?

Again, I'd need to bring to IO team. I'll make sure a possible new
version comes with proper comment.

>
>> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
>> +{
>> +	u32 sssr;
>> +	sssr = read_SSSR(sspc->ioaddr);
>> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
>
> This looks odd, why not sssr & (SSSR_TFL_MASK | SSSR_TNF)?

Agreed.

>
>> +static void flush(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>> +	u32 i = 0;
>> +
>> +	/* If the transmit fifo is not empty, reset the interface. */
>> +	if (!is_tx_fifo_empty(sspc)) {
>> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
>> +		disable_interface(sspc);
>> +		return;
>> +	}
>
> This isn't a flush then?

Analyzing the code I'd say this flush() function is actually a reset
for tx fifo and flush for rx fifo.
Maybe we need a better name for it.

>
>> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
>
> No extra space at the start of the message and why is there a \r in
> there?  Throughout the driver your log messages have a range of odd
> formatting quirks that aren't consistent and don't look like normal
> Linux log messages either.
>
> Please also check the severity of your messages, many of them seem too
> loud.

I'll handle that.

>
>> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
>> +		read_SSDR(reg);
>> +		i++;
>> +	}
>
> What happens if the FIFO doesn't drain?

I'll let Ning answer this question.

>
>> +	WARN(i > 0, "%d words flush occured\n", i);
>
> This seems *very* loud for a flush operation...

Agreed.

>
>> +	if (sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY) {
>> +		sspc->virt_addr_sram_rx = ioremap_nocache(SRAM_BASE_ADDR,
>> +				2 * MAX_SPI_TRANSFER_SIZE);
>
> This doesn't look terribly clever, it's remapping a hard coded address
> rather than getting the address enumerated from a device enumeration
> interface.

I'll check if I can recover this value from somewhere without changing
fw. Otherwise we could mark it as FIXME and change later in a different
patch.

>
>> +	/* get Data Read/Write address */
>> +	ssdr_addr = (dma_addr_t)(sspc->paddr + 0x10);
>
> I'm not entirely sure what this does but it looks dodgy...  what's the
> cast doing for a start?

The answer to your question is: the cast is pointless and can be
removed :)
0x10 is an offset to paddr. We need to replace it by a macro with
proper name to make this clear.

>
>> +		/* In Rx direction, TRAIL Bytes are handled by memcpy */
>
> Please don't randomly CAPITALISE words.

Sorry ABOUT that :)
I'll fix it.

>
>> +	rxdesc = rxchan->device->device_prep_dma_memcpy
>> +		(rxchan,			/* DMA Channel */
>> +		sspc->rx_dma,			/* DAR */
>> +		ssdr_addr,			/* SAR */
>> +		sspc->len_dma_rx,		/* Data Length */
>> +		flag);					/* Flag */
>
> What's going on here?  Why is there a DMAed memcpy()?  This doesn't
> reflect normal DMA usage in SPI drivers at all, I'd expect to see
> dmaengine_prep_ being used.

I'll let this question again to Ning.

>
>> +static void int_transfer_complete(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>> +	struct spi_message *msg;
>> +	struct device *dev = &sspc->pdev->dev;
>> +
>> +	if (unlikely(sspc->quirks & QUIRKS_USE_PM_QOS))
>> +		pm_qos_update_request(&sspc->pm_qos_req,
>> +					PM_QOS_DEFAULT_VALUE);
>
> Why is this a quirk and not abstracted away by the PM QoS API on
> platforms that don't need it?  I'd also expect these updates to be done
> in runtime PM callbacks so that if two transfers follow one another we
> don't bounce the Qos up and down.

Got it. I'll change this code.

>
>> +	dev_dbg(dev, "End of transfer. SSSR:%08X\n", read_SSSR(reg));
>> +	msg = sspc->cur_msg;
>> +	if (likely(msg->complete))
>> +		msg->complete(msg->context);
>> +	complete(&sspc->msg_done);
>
> Remove all these likely()s, they're making the code less clear and seem
> vanishingly unlikely to have any practical impact on performance.

Agreed.

>
>> +static void int_transfer_complete_work(struct work_struct *work)
>> +{
>> +	struct ssp_drv_context *sspc = container_of(work,
>> +				struct ssp_drv_context, complete_work);
>> +
>> +	int_transfer_complete(sspc);
>> +}
>
> This wrapper function doesn't seem terribly useful...  why not just
> inline it into the internal function?

That seems reasonable. I'll change it.

>
>> +	if (status & SSSR_ROR || status & SSSR_TUR) {
>> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
>> +		WARN_ON(1);
>> +		if (status & SSSR_ROR)
>> +			dev_err(dev, "we have Overrun\n");
>> +		if (status & SSSR_TUR)
>> +			dev_err(dev, "we have Underrun\n");
>> +	}
>> +
>> +	/* We can fall here when not using DMA mode */
>> +	if (!sspc->cur_msg) {
>> +		disable_interface(sspc);
>> +		disable_triggers(sspc);
>> +	}
>> +	/* clear status register */
>> +	write_SSSR(sspc->clear_sr, reg);
>
> More comments explaining what's going on here would be good...

We'll provide.

>
>> +static void poll_transfer(unsigned long data)
>> +{
>> +	struct ssp_drv_context *sspc = (void *)data;
>> +
>> +	if (sspc->tx) {
>> +		while (sspc->tx != sspc->tx_end) {
>> +			if (ssp_timing_wr) {
>> +				int timeout = 100;
>> +				/* It is used as debug UART on Tangier. Since
>> +				   baud rate = 115200, it needs at least 312us
>> +				   for one word transferring. Becuase of silicon
>> +				   issue, it MUST check SFIFOL here instead of
>> +				   TNF. It is the workaround for A0 stepping*/
>> +				while (--timeout &&
>> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
>> +					udelay(10);
>> +			}
>
> This doesn't look like it shouldn't be here at all or should be made
> more generic but I can't really tell what it's supposed to do...

Ning?

>
>> +static void start_bitbanging(struct ssp_drv_context *sspc)
>> +{
>
> The SPI core has bitbanging helpers which you don't seem to be using.
> However...
>
>> +	/* Bit bang the clock until CSS clears */
>> +	while ((sssr & 0x400000) && (count < MAX_BITBANGING_LOOP)) {
>> +		write_I2CDATA(0x2, i2c_reg);
>> +		udelay(I2C_ACCESS_USDELAY);
>
> ...this code is talking about I2C?
>
>> +		udelay(I2C_ACCESS_USDELAY);
>> +		write_I2CCTRL(0x01070034, i2c_reg);
>
> This appears to be randomly bashing on an absolute register address.

Ouch. I'll fix it.

>
>> +/**
>> + * transfer() - Start a SPI transfer
>> + * @spi:	Pointer to the spi_device struct
>> + * @msg:	Pointer to the spi_message struct
>> + */
>> +static int transfer(struct spi_device *spi, struct spi_message *msg)
>
> Use of plain transfer() has been deprecated since v3.4, you should at
> least be using transfer_one_message().  I've stopped reviewing at this
> point since a lot of the rest of the code is replicating stuff that's in
> the SPI core and will go away when you update to use the current APIs.

Thanks. This driver needs to be rewritten.
I'll make sure to address your feedback in next version.

Br, David


^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 20:08     ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 20:08 UTC (permalink / raw)
  To: Mark Brown
  Cc: ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

Hi Mark,

On 10/29/2013 11:56 AM, Mark Brown wrote:
> On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
>> From: Fei Yang <fei.yang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>>
>> This patch adds driver for ssp spi interface on Intel Mid platform.
>
> Is there not any possibility of code sharing with the PXA SSP IP?  It
> seems odd that Intel would make a second IP of the same name that's
> totally incompatible...  not looked at the register interfaces in detail
> but the register names certainly look familiar.

I need to bring this question to IO team (who wrote this driver)

>
>> +	tristate "SSP SPI controller driver for Intel MID platforms (EXPERIMENTAL)"
>> +	depends on X86_INTEL_MID && SPI_MASTER && INTEL_MID_DMAC
>> +	help
>
> Are these all build time dependencies?  There's certainly no need to
> depend on SPI_MASTER, all drivers are inside an if SPI_MASTER block.
>
>> +static int ssp_timing_wr;
>
> Why is this a static global?

My only answer would be: because a lazy developer decided so :)

>
>> +#ifdef DUMP_RX
>> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
>> +{
>
> Please add this support as a standard feature of the SPI core if it's
> useful, there's nothing specific to this driver in it.  Using trace
> would probably be better than dumping to the console.

Agreed.

>
>> +	static char msg[MAX_SPI_TRANSFER_SIZE];
>
> Where did that limit come from?

Again, I'd need to bring to IO team. I'll make sure a possible new
version comes with proper comment.

>
>> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
>> +{
>> +	u32 sssr;
>> +	sssr = read_SSSR(sspc->ioaddr);
>> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
>
> This looks odd, why not sssr & (SSSR_TFL_MASK | SSSR_TNF)?

Agreed.

>
>> +static void flush(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>> +	u32 i = 0;
>> +
>> +	/* If the transmit fifo is not empty, reset the interface. */
>> +	if (!is_tx_fifo_empty(sspc)) {
>> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
>> +		disable_interface(sspc);
>> +		return;
>> +	}
>
> This isn't a flush then?

Analyzing the code I'd say this flush() function is actually a reset
for tx fifo and flush for rx fifo.
Maybe we need a better name for it.

>
>> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
>
> No extra space at the start of the message and why is there a \r in
> there?  Throughout the driver your log messages have a range of odd
> formatting quirks that aren't consistent and don't look like normal
> Linux log messages either.
>
> Please also check the severity of your messages, many of them seem too
> loud.

I'll handle that.

>
>> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
>> +		read_SSDR(reg);
>> +		i++;
>> +	}
>
> What happens if the FIFO doesn't drain?

I'll let Ning answer this question.

>
>> +	WARN(i > 0, "%d words flush occured\n", i);
>
> This seems *very* loud for a flush operation...

Agreed.

>
>> +	if (sspc->quirks & QUIRKS_SRAM_ADDITIONAL_CPY) {
>> +		sspc->virt_addr_sram_rx = ioremap_nocache(SRAM_BASE_ADDR,
>> +				2 * MAX_SPI_TRANSFER_SIZE);
>
> This doesn't look terribly clever, it's remapping a hard coded address
> rather than getting the address enumerated from a device enumeration
> interface.

I'll check if I can recover this value from somewhere without changing
fw. Otherwise we could mark it as FIXME and change later in a different
patch.

>
>> +	/* get Data Read/Write address */
>> +	ssdr_addr = (dma_addr_t)(sspc->paddr + 0x10);
>
> I'm not entirely sure what this does but it looks dodgy...  what's the
> cast doing for a start?

The answer to your question is: the cast is pointless and can be
removed :)
0x10 is an offset to paddr. We need to replace it by a macro with
proper name to make this clear.

>
>> +		/* In Rx direction, TRAIL Bytes are handled by memcpy */
>
> Please don't randomly CAPITALISE words.

Sorry ABOUT that :)
I'll fix it.

>
>> +	rxdesc = rxchan->device->device_prep_dma_memcpy
>> +		(rxchan,			/* DMA Channel */
>> +		sspc->rx_dma,			/* DAR */
>> +		ssdr_addr,			/* SAR */
>> +		sspc->len_dma_rx,		/* Data Length */
>> +		flag);					/* Flag */
>
> What's going on here?  Why is there a DMAed memcpy()?  This doesn't
> reflect normal DMA usage in SPI drivers at all, I'd expect to see
> dmaengine_prep_ being used.

I'll let this question again to Ning.

>
>> +static void int_transfer_complete(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>> +	struct spi_message *msg;
>> +	struct device *dev = &sspc->pdev->dev;
>> +
>> +	if (unlikely(sspc->quirks & QUIRKS_USE_PM_QOS))
>> +		pm_qos_update_request(&sspc->pm_qos_req,
>> +					PM_QOS_DEFAULT_VALUE);
>
> Why is this a quirk and not abstracted away by the PM QoS API on
> platforms that don't need it?  I'd also expect these updates to be done
> in runtime PM callbacks so that if two transfers follow one another we
> don't bounce the Qos up and down.

Got it. I'll change this code.

>
>> +	dev_dbg(dev, "End of transfer. SSSR:%08X\n", read_SSSR(reg));
>> +	msg = sspc->cur_msg;
>> +	if (likely(msg->complete))
>> +		msg->complete(msg->context);
>> +	complete(&sspc->msg_done);
>
> Remove all these likely()s, they're making the code less clear and seem
> vanishingly unlikely to have any practical impact on performance.

Agreed.

>
>> +static void int_transfer_complete_work(struct work_struct *work)
>> +{
>> +	struct ssp_drv_context *sspc = container_of(work,
>> +				struct ssp_drv_context, complete_work);
>> +
>> +	int_transfer_complete(sspc);
>> +}
>
> This wrapper function doesn't seem terribly useful...  why not just
> inline it into the internal function?

That seems reasonable. I'll change it.

>
>> +	if (status & SSSR_ROR || status & SSSR_TUR) {
>> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
>> +		WARN_ON(1);
>> +		if (status & SSSR_ROR)
>> +			dev_err(dev, "we have Overrun\n");
>> +		if (status & SSSR_TUR)
>> +			dev_err(dev, "we have Underrun\n");
>> +	}
>> +
>> +	/* We can fall here when not using DMA mode */
>> +	if (!sspc->cur_msg) {
>> +		disable_interface(sspc);
>> +		disable_triggers(sspc);
>> +	}
>> +	/* clear status register */
>> +	write_SSSR(sspc->clear_sr, reg);
>
> More comments explaining what's going on here would be good...

We'll provide.

>
>> +static void poll_transfer(unsigned long data)
>> +{
>> +	struct ssp_drv_context *sspc = (void *)data;
>> +
>> +	if (sspc->tx) {
>> +		while (sspc->tx != sspc->tx_end) {
>> +			if (ssp_timing_wr) {
>> +				int timeout = 100;
>> +				/* It is used as debug UART on Tangier. Since
>> +				   baud rate = 115200, it needs at least 312us
>> +				   for one word transferring. Becuase of silicon
>> +				   issue, it MUST check SFIFOL here instead of
>> +				   TNF. It is the workaround for A0 stepping*/
>> +				while (--timeout &&
>> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
>> +					udelay(10);
>> +			}
>
> This doesn't look like it shouldn't be here at all or should be made
> more generic but I can't really tell what it's supposed to do...

Ning?

>
>> +static void start_bitbanging(struct ssp_drv_context *sspc)
>> +{
>
> The SPI core has bitbanging helpers which you don't seem to be using.
> However...
>
>> +	/* Bit bang the clock until CSS clears */
>> +	while ((sssr & 0x400000) && (count < MAX_BITBANGING_LOOP)) {
>> +		write_I2CDATA(0x2, i2c_reg);
>> +		udelay(I2C_ACCESS_USDELAY);
>
> ...this code is talking about I2C?
>
>> +		udelay(I2C_ACCESS_USDELAY);
>> +		write_I2CCTRL(0x01070034, i2c_reg);
>
> This appears to be randomly bashing on an absolute register address.

Ouch. I'll fix it.

>
>> +/**
>> + * transfer() - Start a SPI transfer
>> + * @spi:	Pointer to the spi_device struct
>> + * @msg:	Pointer to the spi_message struct
>> + */
>> +static int transfer(struct spi_device *spi, struct spi_message *msg)
>
> Use of plain transfer() has been deprecated since v3.4, you should at
> least be using transfer_one_message().  I've stopped reviewing at this
> point since a lot of the rest of the code is replicating stuff that's in
> the SPI core and will go away when you update to use the current APIs.

Thanks. This driver needs to be rewritten.
I'll make sure to address your feedback in next version.

Br, David

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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
  2013-10-29 18:31   ` Felipe Balbi
@ 2013-10-29 20:18     ` David Cohen
  -1 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 20:18 UTC (permalink / raw)
  To: balbi; +Cc: broonie, ning.li, linux-kernel, linux-spi, Fei Yang

Hi Felipe,

On 10/29/2013 11:31 AM, Felipe Balbi wrote:
> Hi,
>
> On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
>> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
>> new file mode 100644
>> index 0000000..b3b9fe8
>> --- /dev/null
>> +++ b/drivers/spi/spi-intel-mid-ssp.c
>> @@ -0,0 +1,1506 @@
>> +/*
>> + * spi-intel-mid-ssp.c
>> + * This driver supports Bulverde SSP core used on Intel MID platforms
>> + * It supports SSP of Moorestown & Medfield platforms and handles clock
>> + * slave & master modes.
>> + *
>> + * Copyright (c) 2013, Intel Corporation.
>> + * Contacts: Ning Li <ning.li@intel.com>
>> + *	     David Cohen <david.a.cohen@linux.intel.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>> + * more details.
>> + *
>> + * You should have received a copy of the GNU General Public License along with
>> + * this program; if not, write to the Free Software Foundation, Inc.,
>> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
>> + *
>> + */
>> +
>> +/*
>> + * Note:
>> + *
>> + * Supports DMA and non-interrupt polled transfers.
>> + *
>> + */
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/delay.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/highmem.h>
>> +#include <linux/pci.h>
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/intel_mid_dma.h>
>> +#include <linux/pm_qos.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/completion.h>
>> +#include <asm/intel-mid.h>
>> +
>> +#include <linux/spi/spi.h>
>> +#include <linux/spi/intel_mid_ssp_spi.h>
>> +
>> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
>> +
>> +static int ssp_timing_wr;
>
> this will prevent multiple instances of the same driver.

Yeah. I'll fix it.

>
>> +#ifdef DUMP_RX
>> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
>> +{
>> +	int tlen1 = (len < sz ? len : sz);
>> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
>> +	unsigned char *p;
>> +	static char msg[MAX_SPI_TRANSFER_SIZE];
>> +
>> +	memset(msg, '\0', sizeof(msg));
>> +	p = buf;
>> +	while (p < buf + tlen1)
>> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
>> +
>> +	if (tlen2 > 0) {
>> +		sprintf(msg, "%s .....", msg);
>> +		p = (buf+len) - tlen2;
>> +		while (p < buf + len)
>> +			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
>> +	}
>> +
>> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
>> +		   len-tlen2, len - 1, msg);
>> +}
>> +#endif
>
> either move this to debugfs or stub the function out ifndef DUMP_RX,
> then you don't need the ifdefs when calling it.

Agreed.

>
>> +static inline u8 ssp_cfg_get_mode(u8 ssp_cfg)
>> +{
>> +	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
>
> instead, couldn't you use driver data to pass some flags to the driver ?
> I can't see intel_mid_identify_cpu and having drivers depend on
> arch-specific code is usually a bad practice.

I'll find a way to get rid of this.

>
>> +		return (ssp_cfg) & 0x03;
>> +	else
>
> else isn't needed here

Agreed.

>
>> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
>> +{
>> +	u32 sssr;
>
> blank line here would aid readability
>

Agreed.

>> +	sssr = read_SSSR(sspc->ioaddr);
>> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
>> +		return 0;
>> +	else
>
> else isn't necessary

Agreed.

>
>> +static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
>> +{
>> +	return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
>
> you don't need the outter parenthesis here, GCC should've warned you,
> even.

Yeah. checkpatch supposed to warn too. I'll fix it.

>
>> +static inline void disable_interface(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line here
>
>> +	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
>> +}
>> +
>> +static inline void disable_triggers(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> and here...
>
>> +	write_SSCR1(read_SSCR1(reg) & ~sspc->cr1_sig, reg);
>> +}
>> +
>> +
>> +static void flush(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>> +	u32 i = 0;
>> +
>> +	/* If the transmit fifo is not empty, reset the interface. */
>> +	if (!is_tx_fifo_empty(sspc)) {
>> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
>> +		disable_interface(sspc);
>> +		return;
>> +	}
>
> not so sure, if the transmit fifo isn't empty and you reset it, you
> could end up corrupting data which is about to be shifted into the wire,
> couldn't you ?
>
> Is this a case which would *really* happen in normal conditions ? If so,
> why ?

I'll leave this question to Ning.

>
>> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
>> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
>> +		read_SSDR(reg);
>> +		i++;
>> +	}
>> +	WARN(i > 0, "%d words flush occured\n", i);
>
> similarly, you could be ignoring data you *should* indeed be handling.

That seems the case, yes.

>
>> +
>> +	return;
>
> return statement is unnecessary.

Agreed.

>
>> +static int null_writer(struct ssp_drv_context *sspc)
>
> looks like these two functions (null_\(writer\|reader\)) need some
> documentation. Why do they exist ?

I'll make sure next version has comments for it.

>
>> +static int u8_writer(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
>> +		|| (sspc->tx == sspc->tx_end))
>> +		return 0;
>> +
>> +	write_SSDR(*(u8 *)(sspc->tx), reg);
>> +	++sspc->tx;
>> +
>> +	return 1;
>> +}
>> +
>> +static int u8_reader(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	while ((read_SSSR(reg) & SSSR_RNE)
>> +		&& (sspc->rx < sspc->rx_end)) {
>> +		*(u8 *)(sspc->rx) = read_SSDR(reg);
>> +		++sspc->rx;
>> +	}
>> +
>> +	return sspc->rx == sspc->rx_end;
>> +}
>> +
>> +static int u16_writer(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
>
> the extra comparisson here is superfluous.

Agreed.

>
>> +		|| (sspc->tx == sspc->tx_end))
>> +		return 0;
>> +
>> +	write_SSDR(*(u16 *)(sspc->tx), reg);
>> +	sspc->tx += 2;
>> +
>> +	return 1;
>> +}
>> +
>> +static int u16_reader(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
>> +		*(u16 *)(sspc->rx) = read_SSDR(reg);
>> +		sspc->rx += 2;
>> +	}
>> +
>> +	return sspc->rx == sspc->rx_end;
>> +}
>> +
>> +static int u32_writer(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
>
> the extra comparisson here is superfluous.

Agreed.

>
>> +		|| (sspc->tx == sspc->tx_end))
>> +		return 0;
>> +
>> +	write_SSDR(*(u32 *)(sspc->tx), reg);
>> +	sspc->tx += 4;
>> +
>> +	return 1;
>> +}
>> +
>> +static int u32_reader(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
>> +		*(u32 *)(sspc->rx) = read_SSDR(reg);
>> +		sspc->rx += 4;
>> +	}
>> +
>> +	return sspc->rx == sspc->rx_end;
>> +}
>> +
>> +static bool chan_filter(struct dma_chan *chan, void *param)
>> +{
>> +	struct ssp_drv_context *sspc = param;
>> +
>> +	if (sspc->dmac1 && chan->device->dev == &sspc->dmac1->dev)
>> +		return true;
>> +
>> +	return false;
>> +}
>> +
>> +/**
>> + * unmap_dma_buffers() - Unmap the DMA buffers used during the last transfer.
>> + * @sspc:	Pointer to the private driver context
>> + */
>> +static void unmap_dma_buffers(struct ssp_drv_context *sspc)
>> +{
>> +	struct device *dev = &sspc->pdev->dev;
>> +
>> +	if (!sspc->dma_mapped)
>> +		return;
>
> blank line
>
>> +	dma_unmap_single(dev, sspc->rx_dma, sspc->len, PCI_DMA_FROMDEVICE);
>> +	dma_unmap_single(dev, sspc->tx_dma, sspc->len, PCI_DMA_TODEVICE);
>> +	sspc->dma_mapped = 0;
>
> you shouldn't need this dma_mapped flag here...
>
>> +static void ssp_spi_dma_done(void *arg)
>> +{
>> +	struct callback_param *cb_param = (struct callback_param *)arg;
>> +	struct ssp_drv_context *sspc = cb_param->drv_context;
>> +	struct device *dev = &sspc->pdev->dev;
>> +	void *reg = sspc->ioaddr;
>> +
>> +	if (cb_param->direction == TX_DIRECTION)
>> +		sspc->txdma_done = 1;
>> +	else
>> +		sspc->rxdma_done = 1;
>> +
>> +	dev_dbg(dev, "DMA callback for direction %d [RX done:%d] [TX done:%d]\n",
>> +		cb_param->direction, sspc->rxdma_done,
>> +		sspc->txdma_done);
>> +
>> +	if (sspc->txdma_done && sspc->rxdma_done) {
>> +		/* Clear Status Register */
>> +		write_SSSR(sspc->clear_sr, reg);
>> +		dev_dbg(dev, "DMA done\n");
>> +		/* Disable Triggers to DMA or to CPU*/
>> +		disable_triggers(sspc);
>> +		unmap_dma_buffers(sspc);
>> +
>> +		queue_work(sspc->dma_wq, &sspc->complete_work);
>
> I fail to see the need for this workstruct, why can't you call
> complete() directly ?
>
>> +static irqreturn_t ssp_int(int irq, void *dev_id)
>> +{
>> +	struct ssp_drv_context *sspc = dev_id;
>> +	void *reg = sspc->ioaddr;
>> +	struct device *dev = &sspc->pdev->dev;
>> +	u32 status = read_SSSR(reg);
>> +
>> +	/* It should never be our interrupt since SSP will */
>> +	/* only trigs interrupt for under/over run.        */
>
> wrong comment style

I'll fix it

>
>> +	if (likely(!(status & sspc->mask_sr)))
>> +		return IRQ_NONE;
>> +
>> +	if (status & SSSR_ROR || status & SSSR_TUR) {
>> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
>> +		WARN_ON(1);
>> +		if (status & SSSR_ROR)
>> +			dev_err(dev, "we have Overrun\n");
>> +		if (status & SSSR_TUR)
>> +			dev_err(dev, "we have Underrun\n");
>> +	}
>
> I would split these two caes here:
>
> if (status & ROR)
> 	dev_WARN(dev, "Overrun\n");
>
> if (status & TUR)
> 	dev_WARN(dev, "Underrun\n");
>
> no need for nested ifs.

Agreed.

>
>> +static void poll_transfer(unsigned long data)
>> +{
>> +	struct ssp_drv_context *sspc = (void *)data;
>> +
>> +	if (sspc->tx) {
>> +		while (sspc->tx != sspc->tx_end) {
>> +			if (ssp_timing_wr) {
>> +				int timeout = 100;
>> +				/* It is used as debug UART on Tangier. Since
>> +				   baud rate = 115200, it needs at least 312us
>> +				   for one word transferring. Becuase of silicon
>> +				   issue, it MUST check SFIFOL here instead of
>> +				   TNF. It is the workaround for A0 stepping*/
>
> wrong comment style.

I'll fix it.

>
>> +				while (--timeout &&
>> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
>> +					udelay(10);
>> +			}
>> +			sspc->write(sspc);
>> +			sspc->read(sspc);
>> +		}
>> +	}
>
> you can make this look sligthly better if you:
>
> if (!sspc->tx)
> 	bail();
>
> while (sspc->tx != sspc->tx_end) {
> 	if (sspc->timing_wr) {
> 		int timeout = 100;
>
> 		....
> 	}
> }
>
> it'll decrease one indentation level.

I'll consider it in next version.

>
>> +static void start_bitbanging(struct ssp_drv_context *sspc)
>
> I would prefix with ssp_

That makes sense.

>
>> +static int handle_message(struct ssp_drv_context *sspc)
>> +{
>> +	struct chip_data *chip = NULL;
>> +	struct spi_transfer *transfer = NULL;
>> +	void *reg = sspc->ioaddr;
>> +	u32 cr1;
>> +	struct device *dev = &sspc->pdev->dev;
>> +	struct spi_message *msg = sspc->cur_msg;
>> +
>> +	chip = spi_get_ctldata(msg->spi);
>> +
>> +	/* We handle only one transfer message since the protocol module has to
>> +	   control the out of band signaling. */
>
> wrong comment style.

I'll fix it.

>
>> +	transfer = list_entry(msg->transfers.next, struct spi_transfer,
>> +					transfer_list);
>> +
>> +	/* Check transfer length */
>> +	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
>> +		(transfer->len == 0))) {
>> +		dev_warn(dev, "transfer length null or greater than %d\n",
>> +			MAX_SPI_TRANSFER_SIZE);
>> +		dev_warn(dev, "length = %d\n", transfer->len);
>> +		msg->status = -EINVAL;
>> +
>> +		if (msg->complete)
>> +			msg->complete(msg->context);
>> +		complete(&sspc->msg_done);
>> +		return 0;
>> +	}
>> +
>> +	/* Flush any remaining data (in case of failed previous transfer) */
>> +	flush(sspc);
>> +
>> +	sspc->tx  = (void *)transfer->tx_buf;
>> +	sspc->rx  = (void *)transfer->rx_buf;
>> +	sspc->len = transfer->len;
>> +	sspc->write = chip->write;
>> +	sspc->read = chip->read;
>> +
>> +	if (likely(chip->dma_enabled)) {
>> +		sspc->dma_mapped = map_dma_buffers(sspc);
>> +		if (unlikely(!sspc->dma_mapped))
>> +			return 0;
>> +	} else {
>> +		sspc->write = sspc->tx ? chip->write : null_writer;
>> +		sspc->read  = sspc->rx ? chip->read : null_reader;
>> +	}
>> +	sspc->tx_end = sspc->tx + transfer->len;
>> +	sspc->rx_end = sspc->rx + transfer->len;
>> +	write_SSSR(sspc->clear_sr, reg);
>> +
>> +	/* setup the CR1 control register */
>> +	cr1 = chip->cr1 | sspc->cr1_sig;
>> +
>> +	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
>> +		/* in case of len smaller than burst size, adjust the RX     */
>> +		/* threshold. All other cases will use the default threshold */
>> +		/* value. The RX fifo threshold must be aligned with the DMA */
>> +		/* RX transfer size, which may be limited to a multiple of 4 */
>> +		/* bytes due to 32bits DDR access.                           */
>
> wrong comment style

Ditto

>
>> +static int ssp_spi_probe(struct pci_dev *pdev,
>> +	const struct pci_device_id *ent)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct spi_master *master;
>> +	struct ssp_drv_context *sspc = 0;
>> +	int status;
>> +	u32 iolen = 0;
>> +	u8 ssp_cfg;
>> +	int pos;
>> +	void __iomem *syscfg_ioaddr;
>> +	unsigned long syscfg;
>> +
>> +	/* Check if the SSP we are probed for has been allocated */
>> +	/* to operate as SPI. This information is retreived from */
>> +	/* the field adid of the Vendor-Specific PCI capability  */
>> +	/* which is used as a configuration register.            */
>
> wrong comment style

Ditto

>
>> +static int ssp_spi_runtime_suspend(struct device *dev)
>> +{
>> +	return 0;
>> +}
>> +
>> +static int ssp_spi_runtime_resume(struct device *dev)
>> +{
>> +	return 0;
>> +}
>
> why even add these if they're no-ops ?

I'll remove them.

>
>> +static int __init ssp_spi_init(void)
>> +{
>> +	return pci_register_driver(&ssp_spi_driver);
>> +}
>> +
>> +late_initcall(ssp_spi_init);
>
> does it have to be late ? Can't you just use module_pci_driver()
> instead ?

I'll let Ning to answer this.

>
>> @@ -0,0 +1,330 @@
>> +/*
>> + *  Copyright (C) Intel 2013
>> + *
>> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + *
>> + *  This program is free software; you can redistribute it and/or modify
>> + *  it under the terms of the GNU General Public License as published by
>> + *  the Free Software Foundation; either version 2 of the License, or
>> + *  (at your option) any later version.
>
> companies usually don't like this "at your option any later version"
> statement. Usually it's GPL2 only...

Hm. I've no opinion about. :)
But I'll make sure this follows the same standard of .c file.

Br, David


^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-29 20:18     ` David Cohen
  0 siblings, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-10-29 20:18 UTC (permalink / raw)
  To: balbi-l0cyMroinI0
  Cc: broonie-DgEjT+Ai2ygdnm+yROfE0A, ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

Hi Felipe,

On 10/29/2013 11:31 AM, Felipe Balbi wrote:
> Hi,
>
> On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
>> diff --git a/drivers/spi/spi-intel-mid-ssp.c b/drivers/spi/spi-intel-mid-ssp.c
>> new file mode 100644
>> index 0000000..b3b9fe8
>> --- /dev/null
>> +++ b/drivers/spi/spi-intel-mid-ssp.c
>> @@ -0,0 +1,1506 @@
>> +/*
>> + * spi-intel-mid-ssp.c
>> + * This driver supports Bulverde SSP core used on Intel MID platforms
>> + * It supports SSP of Moorestown & Medfield platforms and handles clock
>> + * slave & master modes.
>> + *
>> + * Copyright (c) 2013, Intel Corporation.
>> + * Contacts: Ning Li <ning.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>> + *	     David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>> + * more details.
>> + *
>> + * You should have received a copy of the GNU General Public License along with
>> + * this program; if not, write to the Free Software Foundation, Inc.,
>> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
>> + *
>> + */
>> +
>> +/*
>> + * Note:
>> + *
>> + * Supports DMA and non-interrupt polled transfers.
>> + *
>> + */
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/delay.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/highmem.h>
>> +#include <linux/pci.h>
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/intel_mid_dma.h>
>> +#include <linux/pm_qos.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/completion.h>
>> +#include <asm/intel-mid.h>
>> +
>> +#include <linux/spi/spi.h>
>> +#include <linux/spi/intel_mid_ssp_spi.h>
>> +
>> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
>> +
>> +static int ssp_timing_wr;
>
> this will prevent multiple instances of the same driver.

Yeah. I'll fix it.

>
>> +#ifdef DUMP_RX
>> +static void dump_trailer(const struct device *dev, char *buf, int len, int sz)
>> +{
>> +	int tlen1 = (len < sz ? len : sz);
>> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
>> +	unsigned char *p;
>> +	static char msg[MAX_SPI_TRANSFER_SIZE];
>> +
>> +	memset(msg, '\0', sizeof(msg));
>> +	p = buf;
>> +	while (p < buf + tlen1)
>> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
>> +
>> +	if (tlen2 > 0) {
>> +		sprintf(msg, "%s .....", msg);
>> +		p = (buf+len) - tlen2;
>> +		while (p < buf + len)
>> +			sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
>> +	}
>> +
>> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 - 1,
>> +		   len-tlen2, len - 1, msg);
>> +}
>> +#endif
>
> either move this to debugfs or stub the function out ifndef DUMP_RX,
> then you don't need the ifdefs when calling it.

Agreed.

>
>> +static inline u8 ssp_cfg_get_mode(u8 ssp_cfg)
>> +{
>> +	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
>
> instead, couldn't you use driver data to pass some flags to the driver ?
> I can't see intel_mid_identify_cpu and having drivers depend on
> arch-specific code is usually a bad practice.

I'll find a way to get rid of this.

>
>> +		return (ssp_cfg) & 0x03;
>> +	else
>
> else isn't needed here

Agreed.

>
>> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
>> +{
>> +	u32 sssr;
>
> blank line here would aid readability
>

Agreed.

>> +	sssr = read_SSSR(sspc->ioaddr);
>> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
>> +		return 0;
>> +	else
>
> else isn't necessary

Agreed.

>
>> +static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
>> +{
>> +	return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
>
> you don't need the outter parenthesis here, GCC should've warned you,
> even.

Yeah. checkpatch supposed to warn too. I'll fix it.

>
>> +static inline void disable_interface(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line here
>
>> +	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
>> +}
>> +
>> +static inline void disable_triggers(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> and here...
>
>> +	write_SSCR1(read_SSCR1(reg) & ~sspc->cr1_sig, reg);
>> +}
>> +
>> +
>> +static void flush(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>> +	u32 i = 0;
>> +
>> +	/* If the transmit fifo is not empty, reset the interface. */
>> +	if (!is_tx_fifo_empty(sspc)) {
>> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty. Reset of SPI IF");
>> +		disable_interface(sspc);
>> +		return;
>> +	}
>
> not so sure, if the transmit fifo isn't empty and you reset it, you
> could end up corrupting data which is about to be shifted into the wire,
> couldn't you ?
>
> Is this a case which would *really* happen in normal conditions ? If so,
> why ?

I'll leave this question to Ning.

>
>> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
>> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE + 1)) {
>> +		read_SSDR(reg);
>> +		i++;
>> +	}
>> +	WARN(i > 0, "%d words flush occured\n", i);
>
> similarly, you could be ignoring data you *should* indeed be handling.

That seems the case, yes.

>
>> +
>> +	return;
>
> return statement is unnecessary.

Agreed.

>
>> +static int null_writer(struct ssp_drv_context *sspc)
>
> looks like these two functions (null_\(writer\|reader\)) need some
> documentation. Why do they exist ?

I'll make sure next version has comments for it.

>
>> +static int u8_writer(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
>> +		|| (sspc->tx == sspc->tx_end))
>> +		return 0;
>> +
>> +	write_SSDR(*(u8 *)(sspc->tx), reg);
>> +	++sspc->tx;
>> +
>> +	return 1;
>> +}
>> +
>> +static int u8_reader(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	while ((read_SSSR(reg) & SSSR_RNE)
>> +		&& (sspc->rx < sspc->rx_end)) {
>> +		*(u8 *)(sspc->rx) = read_SSDR(reg);
>> +		++sspc->rx;
>> +	}
>> +
>> +	return sspc->rx == sspc->rx_end;
>> +}
>> +
>> +static int u16_writer(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
>
> the extra comparisson here is superfluous.

Agreed.

>
>> +		|| (sspc->tx == sspc->tx_end))
>> +		return 0;
>> +
>> +	write_SSDR(*(u16 *)(sspc->tx), reg);
>> +	sspc->tx += 2;
>> +
>> +	return 1;
>> +}
>> +
>> +static int u16_reader(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
>> +		*(u16 *)(sspc->rx) = read_SSDR(reg);
>> +		sspc->rx += 2;
>> +	}
>> +
>> +	return sspc->rx == sspc->rx_end;
>> +}
>> +
>> +static int u32_writer(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
>
> the extra comparisson here is superfluous.

Agreed.

>
>> +		|| (sspc->tx == sspc->tx_end))
>> +		return 0;
>> +
>> +	write_SSDR(*(u32 *)(sspc->tx), reg);
>> +	sspc->tx += 4;
>> +
>> +	return 1;
>> +}
>> +
>> +static int u32_reader(struct ssp_drv_context *sspc)
>> +{
>> +	void *reg = sspc->ioaddr;
>
> blank line
>
>> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx < sspc->rx_end)) {
>> +		*(u32 *)(sspc->rx) = read_SSDR(reg);
>> +		sspc->rx += 4;
>> +	}
>> +
>> +	return sspc->rx == sspc->rx_end;
>> +}
>> +
>> +static bool chan_filter(struct dma_chan *chan, void *param)
>> +{
>> +	struct ssp_drv_context *sspc = param;
>> +
>> +	if (sspc->dmac1 && chan->device->dev == &sspc->dmac1->dev)
>> +		return true;
>> +
>> +	return false;
>> +}
>> +
>> +/**
>> + * unmap_dma_buffers() - Unmap the DMA buffers used during the last transfer.
>> + * @sspc:	Pointer to the private driver context
>> + */
>> +static void unmap_dma_buffers(struct ssp_drv_context *sspc)
>> +{
>> +	struct device *dev = &sspc->pdev->dev;
>> +
>> +	if (!sspc->dma_mapped)
>> +		return;
>
> blank line
>
>> +	dma_unmap_single(dev, sspc->rx_dma, sspc->len, PCI_DMA_FROMDEVICE);
>> +	dma_unmap_single(dev, sspc->tx_dma, sspc->len, PCI_DMA_TODEVICE);
>> +	sspc->dma_mapped = 0;
>
> you shouldn't need this dma_mapped flag here...
>
>> +static void ssp_spi_dma_done(void *arg)
>> +{
>> +	struct callback_param *cb_param = (struct callback_param *)arg;
>> +	struct ssp_drv_context *sspc = cb_param->drv_context;
>> +	struct device *dev = &sspc->pdev->dev;
>> +	void *reg = sspc->ioaddr;
>> +
>> +	if (cb_param->direction == TX_DIRECTION)
>> +		sspc->txdma_done = 1;
>> +	else
>> +		sspc->rxdma_done = 1;
>> +
>> +	dev_dbg(dev, "DMA callback for direction %d [RX done:%d] [TX done:%d]\n",
>> +		cb_param->direction, sspc->rxdma_done,
>> +		sspc->txdma_done);
>> +
>> +	if (sspc->txdma_done && sspc->rxdma_done) {
>> +		/* Clear Status Register */
>> +		write_SSSR(sspc->clear_sr, reg);
>> +		dev_dbg(dev, "DMA done\n");
>> +		/* Disable Triggers to DMA or to CPU*/
>> +		disable_triggers(sspc);
>> +		unmap_dma_buffers(sspc);
>> +
>> +		queue_work(sspc->dma_wq, &sspc->complete_work);
>
> I fail to see the need for this workstruct, why can't you call
> complete() directly ?
>
>> +static irqreturn_t ssp_int(int irq, void *dev_id)
>> +{
>> +	struct ssp_drv_context *sspc = dev_id;
>> +	void *reg = sspc->ioaddr;
>> +	struct device *dev = &sspc->pdev->dev;
>> +	u32 status = read_SSSR(reg);
>> +
>> +	/* It should never be our interrupt since SSP will */
>> +	/* only trigs interrupt for under/over run.        */
>
> wrong comment style

I'll fix it

>
>> +	if (likely(!(status & sspc->mask_sr)))
>> +		return IRQ_NONE;
>> +
>> +	if (status & SSSR_ROR || status & SSSR_TUR) {
>> +		dev_err(dev, "--- SPI ROR or TUR occurred : SSSR=%x\n",	status);
>> +		WARN_ON(1);
>> +		if (status & SSSR_ROR)
>> +			dev_err(dev, "we have Overrun\n");
>> +		if (status & SSSR_TUR)
>> +			dev_err(dev, "we have Underrun\n");
>> +	}
>
> I would split these two caes here:
>
> if (status & ROR)
> 	dev_WARN(dev, "Overrun\n");
>
> if (status & TUR)
> 	dev_WARN(dev, "Underrun\n");
>
> no need for nested ifs.

Agreed.

>
>> +static void poll_transfer(unsigned long data)
>> +{
>> +	struct ssp_drv_context *sspc = (void *)data;
>> +
>> +	if (sspc->tx) {
>> +		while (sspc->tx != sspc->tx_end) {
>> +			if (ssp_timing_wr) {
>> +				int timeout = 100;
>> +				/* It is used as debug UART on Tangier. Since
>> +				   baud rate = 115200, it needs at least 312us
>> +				   for one word transferring. Becuase of silicon
>> +				   issue, it MUST check SFIFOL here instead of
>> +				   TNF. It is the workaround for A0 stepping*/
>
> wrong comment style.

I'll fix it.

>
>> +				while (--timeout &&
>> +					((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
>> +					udelay(10);
>> +			}
>> +			sspc->write(sspc);
>> +			sspc->read(sspc);
>> +		}
>> +	}
>
> you can make this look sligthly better if you:
>
> if (!sspc->tx)
> 	bail();
>
> while (sspc->tx != sspc->tx_end) {
> 	if (sspc->timing_wr) {
> 		int timeout = 100;
>
> 		....
> 	}
> }
>
> it'll decrease one indentation level.

I'll consider it in next version.

>
>> +static void start_bitbanging(struct ssp_drv_context *sspc)
>
> I would prefix with ssp_

That makes sense.

>
>> +static int handle_message(struct ssp_drv_context *sspc)
>> +{
>> +	struct chip_data *chip = NULL;
>> +	struct spi_transfer *transfer = NULL;
>> +	void *reg = sspc->ioaddr;
>> +	u32 cr1;
>> +	struct device *dev = &sspc->pdev->dev;
>> +	struct spi_message *msg = sspc->cur_msg;
>> +
>> +	chip = spi_get_ctldata(msg->spi);
>> +
>> +	/* We handle only one transfer message since the protocol module has to
>> +	   control the out of band signaling. */
>
> wrong comment style.

I'll fix it.

>
>> +	transfer = list_entry(msg->transfers.next, struct spi_transfer,
>> +					transfer_list);
>> +
>> +	/* Check transfer length */
>> +	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
>> +		(transfer->len == 0))) {
>> +		dev_warn(dev, "transfer length null or greater than %d\n",
>> +			MAX_SPI_TRANSFER_SIZE);
>> +		dev_warn(dev, "length = %d\n", transfer->len);
>> +		msg->status = -EINVAL;
>> +
>> +		if (msg->complete)
>> +			msg->complete(msg->context);
>> +		complete(&sspc->msg_done);
>> +		return 0;
>> +	}
>> +
>> +	/* Flush any remaining data (in case of failed previous transfer) */
>> +	flush(sspc);
>> +
>> +	sspc->tx  = (void *)transfer->tx_buf;
>> +	sspc->rx  = (void *)transfer->rx_buf;
>> +	sspc->len = transfer->len;
>> +	sspc->write = chip->write;
>> +	sspc->read = chip->read;
>> +
>> +	if (likely(chip->dma_enabled)) {
>> +		sspc->dma_mapped = map_dma_buffers(sspc);
>> +		if (unlikely(!sspc->dma_mapped))
>> +			return 0;
>> +	} else {
>> +		sspc->write = sspc->tx ? chip->write : null_writer;
>> +		sspc->read  = sspc->rx ? chip->read : null_reader;
>> +	}
>> +	sspc->tx_end = sspc->tx + transfer->len;
>> +	sspc->rx_end = sspc->rx + transfer->len;
>> +	write_SSSR(sspc->clear_sr, reg);
>> +
>> +	/* setup the CR1 control register */
>> +	cr1 = chip->cr1 | sspc->cr1_sig;
>> +
>> +	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
>> +		/* in case of len smaller than burst size, adjust the RX     */
>> +		/* threshold. All other cases will use the default threshold */
>> +		/* value. The RX fifo threshold must be aligned with the DMA */
>> +		/* RX transfer size, which may be limited to a multiple of 4 */
>> +		/* bytes due to 32bits DDR access.                           */
>
> wrong comment style

Ditto

>
>> +static int ssp_spi_probe(struct pci_dev *pdev,
>> +	const struct pci_device_id *ent)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct spi_master *master;
>> +	struct ssp_drv_context *sspc = 0;
>> +	int status;
>> +	u32 iolen = 0;
>> +	u8 ssp_cfg;
>> +	int pos;
>> +	void __iomem *syscfg_ioaddr;
>> +	unsigned long syscfg;
>> +
>> +	/* Check if the SSP we are probed for has been allocated */
>> +	/* to operate as SPI. This information is retreived from */
>> +	/* the field adid of the Vendor-Specific PCI capability  */
>> +	/* which is used as a configuration register.            */
>
> wrong comment style

Ditto

>
>> +static int ssp_spi_runtime_suspend(struct device *dev)
>> +{
>> +	return 0;
>> +}
>> +
>> +static int ssp_spi_runtime_resume(struct device *dev)
>> +{
>> +	return 0;
>> +}
>
> why even add these if they're no-ops ?

I'll remove them.

>
>> +static int __init ssp_spi_init(void)
>> +{
>> +	return pci_register_driver(&ssp_spi_driver);
>> +}
>> +
>> +late_initcall(ssp_spi_init);
>
> does it have to be late ? Can't you just use module_pci_driver()
> instead ?

I'll let Ning to answer this.

>
>> @@ -0,0 +1,330 @@
>> +/*
>> + *  Copyright (C) Intel 2013
>> + *
>> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + *
>> + *  This program is free software; you can redistribute it and/or modify
>> + *  it under the terms of the GNU General Public License as published by
>> + *  the Free Software Foundation; either version 2 of the License, or
>> + *  (at your option) any later version.
>
> companies usually don't like this "at your option any later version"
> statement. Usually it's GPL2 only...

Hm. I've no opinion about. :)
But I'll make sure this follows the same standard of .c file.

Br, David

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^ permalink raw reply	[flat|nested] 36+ messages in thread

* [PATCH] checkpatch: Improve "return is not a function" test
  2013-10-29 19:38           ` Joe Perches
  (?)
@ 2013-10-29 20:28           ` Joe Perches
  -1 siblings, 0 replies; 36+ messages in thread
From: Joe Perches @ 2013-10-29 20:28 UTC (permalink / raw)
  To: Andrew Morton, Andy Whitcroft; +Cc: David Cohen, linux-kernel

Find a few more cases where parentheses are used around
the value of a return statement.

This also makes the test depend on perl v5.10 and higher.

Signed-off-by: Joe Perches <joe@perches.com>
---
 scripts/checkpatch.pl | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 23d55bf..957ba04 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3221,21 +3221,10 @@ sub process {
 		}
 
 # Return is not a function.
-		if (defined($stat) && $stat =~ /^.\s*return(\s*)(\(.*);/s) {
+		if (defined($stat) && $stat =~ /^.\s*return(\s*)\(/s) {
 			my $spacing = $1;
-			my $value = $2;
-
-			# Flatten any parentheses
-			$value =~ s/\(/ \(/g;
-			$value =~ s/\)/\) /g;
-			while ($value =~ s/\[[^\[\]]*\]/1/ ||
-			       $value !~ /(?:$Ident|-?$Constant)\s*
-					     $Compare\s*
-					     (?:$Ident|-?$Constant)/x &&
-			       $value =~ s/\([^\(\)]*\)/1/) {
-			}
-#print "value<$value>\n";
-			if ($value =~ /^\s*(?:$Ident|-?$Constant)\s*$/) {
+			if ($^V && $^V ge 5.10.0 &&
+			    $stat =~ /^.\s*return\s*$balanced_parens\s*;\s*$/) {
 				ERROR("RETURN_PARENTHESES",
 				      "return is not a function, parentheses are not required\n" . $herecurr);
 
@@ -3244,6 +3233,7 @@ sub process {
 				      "space required before the open parenthesis '('\n" . $herecurr);
 			}
 		}
+
 # Return of what appears to be an errno should normally be -'ve
 		if ($line =~ /^.\s*return\s*(E[A-Z]*)\s*;/) {
 			my $name = $1;



^ permalink raw reply related	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-30  1:42   ` Randy Dunlap
  0 siblings, 0 replies; 36+ messages in thread
From: Randy Dunlap @ 2013-10-30  1:42 UTC (permalink / raw)
  To: David Cohen, broonie; +Cc: ning.li, linux-kernel, linux-spi, Fei Yang

On 10/29/13 11:05, David Cohen wrote:

a few more comments:

> +static unsigned int ssp_get_clk_div(int speed)
> +{
> +	return max(100000000 / speed, 4) - 1;

Divide uses library call?  I dunno...
Bad if so.  Would need to use some function from
#include <asm-generic/div64.h>

> +}

> +/**
> + * setup() - Driver setup procedure
> + * @spi:	Pointeur to the spi_device struct

		Pointer

> + */
> +static int setup(struct spi_device *spi)
> +{
> +}
> +/**
> + * ssp_spi_probe() - Driver probe procedure
> + * @pdev:	Pointer to the pci_dev struct
> + * @ent:	Pointer to the pci_device_id struct
> + */
> +static int ssp_spi_probe(struct pci_dev *pdev,
> +	const struct pci_device_id *ent)
> +{
> +	/* Set platform & configuration quirks */
> +	if (sspc->quirks & QUIRKS_PLATFORM_MRST) {
> +		/* Apply bit banging workarround on MRST */

		                     workaround

> +		sspc->quirks |= QUIRKS_BIT_BANGING;
> +		/* MRST slave mode workarrounds */

		                   workarounds

> +		if (ssp_cfg_is_spi_slave(ssp_cfg))
> +			sspc->quirks |= QUIRKS_USE_PM_QOS |
> +					QUIRKS_SRAM_ADDITIONAL_CPY;
> +	}
> +	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
> +		ssp_timing_wr = 1;
> +
> +	if (status < 0) {
> +		dev_err(&pdev->dev, "can not get IRQ\n");

		                     cannot

> +		goto err_free_4;
> +	}
> +
> +}

> +MODULE_AUTHOR("Ken Mills");
> +MODULE_DESCRIPTION("Bulverde SSP core SPI contoller");

                                             controller

> +MODULE_LICENSE("GPL");


-- 
~Randy

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-30  1:42   ` Randy Dunlap
  0 siblings, 0 replies; 36+ messages in thread
From: Randy Dunlap @ 2013-10-30  1:42 UTC (permalink / raw)
  To: David Cohen, broonie-DgEjT+Ai2ygdnm+yROfE0A
  Cc: ning.li-ral2JQCrhuEAvxtiuMwx3w,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

On 10/29/13 11:05, David Cohen wrote:

a few more comments:

> +static unsigned int ssp_get_clk_div(int speed)
> +{
> +	return max(100000000 / speed, 4) - 1;

Divide uses library call?  I dunno...
Bad if so.  Would need to use some function from
#include <asm-generic/div64.h>

> +}

> +/**
> + * setup() - Driver setup procedure
> + * @spi:	Pointeur to the spi_device struct

		Pointer

> + */
> +static int setup(struct spi_device *spi)
> +{
> +}
> +/**
> + * ssp_spi_probe() - Driver probe procedure
> + * @pdev:	Pointer to the pci_dev struct
> + * @ent:	Pointer to the pci_device_id struct
> + */
> +static int ssp_spi_probe(struct pci_dev *pdev,
> +	const struct pci_device_id *ent)
> +{
> +	/* Set platform & configuration quirks */
> +	if (sspc->quirks & QUIRKS_PLATFORM_MRST) {
> +		/* Apply bit banging workarround on MRST */

		                     workaround

> +		sspc->quirks |= QUIRKS_BIT_BANGING;
> +		/* MRST slave mode workarrounds */

		                   workarounds

> +		if (ssp_cfg_is_spi_slave(ssp_cfg))
> +			sspc->quirks |= QUIRKS_USE_PM_QOS |
> +					QUIRKS_SRAM_ADDITIONAL_CPY;
> +	}
> +	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
> +		ssp_timing_wr = 1;
> +
> +	if (status < 0) {
> +		dev_err(&pdev->dev, "can not get IRQ\n");

		                     cannot

> +		goto err_free_4;
> +	}
> +
> +}

> +MODULE_AUTHOR("Ken Mills");
> +MODULE_DESCRIPTION("Bulverde SSP core SPI contoller");

                                             controller

> +MODULE_LICENSE("GPL");


-- 
~Randy
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^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-30  3:26       ` Ning Li
  0 siblings, 0 replies; 36+ messages in thread
From: Ning Li @ 2013-10-30  3:26 UTC (permalink / raw)
  To: David Cohen; +Cc: balbi, broonie, linux-kernel, linux-spi, Fei Yang

On Tue, 29 Oct 2013 13:18:37 -0700
David Cohen <david.a.cohen@linux.intel.com> wrote:

> Hi Felipe,
> 
> On 10/29/2013 11:31 AM, Felipe Balbi wrote:
> > Hi,
> >
> > On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
> >> diff --git a/drivers/spi/spi-intel-mid-ssp.c
> >> b/drivers/spi/spi-intel-mid-ssp.c new file mode 100644
> >> index 0000000..b3b9fe8
> >> --- /dev/null
> >> +++ b/drivers/spi/spi-intel-mid-ssp.c
> >> @@ -0,0 +1,1506 @@
> >> +/*
> >> + * spi-intel-mid-ssp.c
> >> + * This driver supports Bulverde SSP core used on Intel MID
> >> platforms
> >> + * It supports SSP of Moorestown & Medfield platforms and handles
> >> clock
> >> + * slave & master modes.
> >> + *
> >> + * Copyright (c) 2013, Intel Corporation.
> >> + * Contacts: Ning Li <ning.li@intel.com>
> >> + *	     David Cohen <david.a.cohen@linux.intel.com>
> >> + *
> >> + * This program is free software; you can redistribute it and/or
> >> modify it
> >> + * under the terms and conditions of the GNU General Public
> >> License,
> >> + * version 2, as published by the Free Software Foundation.
> >> + *
> >> + * This program is distributed in the hope it will be useful, but
> >> WITHOUT
> >> + * ANY WARRANTY; without even the implied warranty of
> >> MERCHANTABILITY or
> >> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
> >> License for
> >> + * more details.
> >> + *
> >> + * You should have received a copy of the GNU General Public
> >> License along with
> >> + * this program; if not, write to the Free Software Foundation,
> >> Inc.,
> >> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> >> + *
> >> + */
> >> +
> >> +/*
> >> + * Note:
> >> + *
> >> + * Supports DMA and non-interrupt polled transfers.
> >> + *
> >> + */
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/delay.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/highmem.h>
> >> +#include <linux/pci.h>
> >> +#include <linux/init.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/dma-mapping.h>
> >> +#include <linux/intel_mid_dma.h>
> >> +#include <linux/pm_qos.h>
> >> +#include <linux/pm_runtime.h>
> >> +#include <linux/completion.h>
> >> +#include <asm/intel-mid.h>
> >> +
> >> +#include <linux/spi/spi.h>
> >> +#include <linux/spi/intel_mid_ssp_spi.h>
> >> +
> >> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
> >> +
> >> +static int ssp_timing_wr;
> >
> > this will prevent multiple instances of the same driver.
> 
> Yeah. I'll fix it.
> 
> >
> >> +#ifdef DUMP_RX
> >> +static void dump_trailer(const struct device *dev, char *buf, int
> >> len, int sz) +{
> >> +	int tlen1 = (len < sz ? len : sz);
> >> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
> >> +	unsigned char *p;
> >> +	static char msg[MAX_SPI_TRANSFER_SIZE];
> >> +
> >> +	memset(msg, '\0', sizeof(msg));
> >> +	p = buf;
> >> +	while (p < buf + tlen1)
> >> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> >> +
> >> +	if (tlen2 > 0) {
> >> +		sprintf(msg, "%s .....", msg);
> >> +		p = (buf+len) - tlen2;
> >> +		while (p < buf + len)
> >> +			sprintf(msg, "%s%02x", msg, (unsigned
> >> int)*p++);
> >> +	}
> >> +
> >> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 -
> >> 1,
> >> +		   len-tlen2, len - 1, msg);
> >> +}
> >> +#endif
> >
> > either move this to debugfs or stub the function out ifndef DUMP_RX,
> > then you don't need the ifdefs when calling it.
> 
> Agreed.
> 
> >
> >> +static inline u8 ssp_cfg_get_mode(u8 ssp_cfg)
> >> +{
> >> +	if (intel_mid_identify_cpu() ==
> >> INTEL_MID_CPU_CHIP_TANGIER)
> >
> > instead, couldn't you use driver data to pass some flags to the
> > driver ? I can't see intel_mid_identify_cpu and having drivers
> > depend on arch-specific code is usually a bad practice.
> 
> I'll find a way to get rid of this.
> 
> >
> >> +		return (ssp_cfg) & 0x03;
> >> +	else
> >
> > else isn't needed here
> 
> Agreed.
> 
> >
> >> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
> >> +{
> >> +	u32 sssr;
> >
> > blank line here would aid readability
> >
> 
> Agreed.
> 
> >> +	sssr = read_SSSR(sspc->ioaddr);
> >> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
> >> +		return 0;
> >> +	else
> >
> > else isn't necessary
> 
> Agreed.
> 
> >
> >> +static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> >> +{
> >> +	return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
> >
> > you don't need the outter parenthesis here, GCC should've warned
> > you, even.
> 
> Yeah. checkpatch supposed to warn too. I'll fix it.
> 
> >
> >> +static inline void disable_interface(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line here
> >
> >> +	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
> >> +}
> >> +
> >> +static inline void disable_triggers(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > and here...
> >
> >> +	write_SSCR1(read_SSCR1(reg) & ~sspc->cr1_sig, reg);
> >> +}
> >> +
> >> +
> >> +static void flush(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >> +	u32 i = 0;
> >> +
> >> +	/* If the transmit fifo is not empty, reset the
> >> interface. */
> >> +	if (!is_tx_fifo_empty(sspc)) {
> >> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty.
> >> Reset of SPI IF");
> >> +		disable_interface(sspc);
> >> +		return;
> >> +	}
> >
> > not so sure, if the transmit fifo isn't empty and you reset it, you
> > could end up corrupting data which is about to be shifted into the
> > wire, couldn't you ?
> >
> > Is this a case which would *really* happen in normal conditions ?
> > If so, why ?
> 
> I'll leave this question to Ning.

I did not see it happen before, but maybe the previous author had met
the situation. Actually, it should be safe to disable the port here,
since when setting SSCR.SSE bit to 0, the SSP will be disabled and at
the same time, the FIFOs will be cleared, according to the spec.

> 
> >
> >> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
> >> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE +
> >> 1)) {
> >> +		read_SSDR(reg);
> >> +		i++;
> >> +	}
> >> +	WARN(i > 0, "%d words flush occured\n", i);
> >
> > similarly, you could be ignoring data you *should* indeed be
> > handling.
> 
> That seems the case, yes.
> 
> >
> >> +
> >> +	return;
> >
> > return statement is unnecessary.
> 
> Agreed.
> 
> >
> >> +static int null_writer(struct ssp_drv_context *sspc)
> >
> > looks like these two functions (null_\(writer\|reader\)) need some
> > documentation. Why do they exist ?
> 
> I'll make sure next version has comments for it.
> 
> >
> >> +static int u8_writer(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> >> +		|| (sspc->tx == sspc->tx_end))
> >> +		return 0;
> >> +
> >> +	write_SSDR(*(u8 *)(sspc->tx), reg);
> >> +	++sspc->tx;
> >> +
> >> +	return 1;
> >> +}
> >> +
> >> +static int u8_reader(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	while ((read_SSSR(reg) & SSSR_RNE)
> >> +		&& (sspc->rx < sspc->rx_end)) {
> >> +		*(u8 *)(sspc->rx) = read_SSDR(reg);
> >> +		++sspc->rx;
> >> +	}
> >> +
> >> +	return sspc->rx == sspc->rx_end;
> >> +}
> >> +
> >> +static int u16_writer(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> >
> > the extra comparisson here is superfluous.
> 
> Agreed.
> 
> >
> >> +		|| (sspc->tx == sspc->tx_end))
> >> +		return 0;
> >> +
> >> +	write_SSDR(*(u16 *)(sspc->tx), reg);
> >> +	sspc->tx += 2;
> >> +
> >> +	return 1;
> >> +}
> >> +
> >> +static int u16_reader(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx <
> >> sspc->rx_end)) {
> >> +		*(u16 *)(sspc->rx) = read_SSDR(reg);
> >> +		sspc->rx += 2;
> >> +	}
> >> +
> >> +	return sspc->rx == sspc->rx_end;
> >> +}
> >> +
> >> +static int u32_writer(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> >
> > the extra comparisson here is superfluous.
> 
> Agreed.
> 
> >
> >> +		|| (sspc->tx == sspc->tx_end))
> >> +		return 0;
> >> +
> >> +	write_SSDR(*(u32 *)(sspc->tx), reg);
> >> +	sspc->tx += 4;
> >> +
> >> +	return 1;
> >> +}
> >> +
> >> +static int u32_reader(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx <
> >> sspc->rx_end)) {
> >> +		*(u32 *)(sspc->rx) = read_SSDR(reg);
> >> +		sspc->rx += 4;
> >> +	}
> >> +
> >> +	return sspc->rx == sspc->rx_end;
> >> +}
> >> +
> >> +static bool chan_filter(struct dma_chan *chan, void *param)
> >> +{
> >> +	struct ssp_drv_context *sspc = param;
> >> +
> >> +	if (sspc->dmac1 && chan->device->dev == &sspc->dmac1->dev)
> >> +		return true;
> >> +
> >> +	return false;
> >> +}
> >> +
> >> +/**
> >> + * unmap_dma_buffers() - Unmap the DMA buffers used during the
> >> last transfer.
> >> + * @sspc:	Pointer to the private driver context
> >> + */
> >> +static void unmap_dma_buffers(struct ssp_drv_context *sspc)
> >> +{
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +
> >> +	if (!sspc->dma_mapped)
> >> +		return;
> >
> > blank line
> >
> >> +	dma_unmap_single(dev, sspc->rx_dma, sspc->len,
> >> PCI_DMA_FROMDEVICE);
> >> +	dma_unmap_single(dev, sspc->tx_dma, sspc->len,
> >> PCI_DMA_TODEVICE);
> >> +	sspc->dma_mapped = 0;
> >
> > you shouldn't need this dma_mapped flag here...
> >
> >> +static void ssp_spi_dma_done(void *arg)
> >> +{
> >> +	struct callback_param *cb_param = (struct callback_param
> >> *)arg;
> >> +	struct ssp_drv_context *sspc = cb_param->drv_context;
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +	void *reg = sspc->ioaddr;
> >> +
> >> +	if (cb_param->direction == TX_DIRECTION)
> >> +		sspc->txdma_done = 1;
> >> +	else
> >> +		sspc->rxdma_done = 1;
> >> +
> >> +	dev_dbg(dev, "DMA callback for direction %d [RX done:%d]
> >> [TX done:%d]\n",
> >> +		cb_param->direction, sspc->rxdma_done,
> >> +		sspc->txdma_done);
> >> +
> >> +	if (sspc->txdma_done && sspc->rxdma_done) {
> >> +		/* Clear Status Register */
> >> +		write_SSSR(sspc->clear_sr, reg);
> >> +		dev_dbg(dev, "DMA done\n");
> >> +		/* Disable Triggers to DMA or to CPU*/
> >> +		disable_triggers(sspc);
> >> +		unmap_dma_buffers(sspc);
> >> +
> >> +		queue_work(sspc->dma_wq, &sspc->complete_work);
> >
> > I fail to see the need for this workstruct, why can't you call
> > complete() directly ?
> >
> >> +static irqreturn_t ssp_int(int irq, void *dev_id)
> >> +{
> >> +	struct ssp_drv_context *sspc = dev_id;
> >> +	void *reg = sspc->ioaddr;
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +	u32 status = read_SSSR(reg);
> >> +
> >> +	/* It should never be our interrupt since SSP will */
> >> +	/* only trigs interrupt for under/over run.        */
> >
> > wrong comment style
> 
> I'll fix it
> 
> >
> >> +	if (likely(!(status & sspc->mask_sr)))
> >> +		return IRQ_NONE;
> >> +
> >> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> >> +		dev_err(dev, "--- SPI ROR or TUR occurred :
> >> SSSR=%x\n",	status);
> >> +		WARN_ON(1);
> >> +		if (status & SSSR_ROR)
> >> +			dev_err(dev, "we have Overrun\n");
> >> +		if (status & SSSR_TUR)
> >> +			dev_err(dev, "we have Underrun\n");
> >> +	}
> >
> > I would split these two caes here:
> >
> > if (status & ROR)
> > 	dev_WARN(dev, "Overrun\n");
> >
> > if (status & TUR)
> > 	dev_WARN(dev, "Underrun\n");
> >
> > no need for nested ifs.
> 
> Agreed.
> 
> >
> >> +static void poll_transfer(unsigned long data)
> >> +{
> >> +	struct ssp_drv_context *sspc = (void *)data;
> >> +
> >> +	if (sspc->tx) {
> >> +		while (sspc->tx != sspc->tx_end) {
> >> +			if (ssp_timing_wr) {
> >> +				int timeout = 100;
> >> +				/* It is used as debug UART on
> >> Tangier. Since
> >> +				   baud rate = 115200, it needs
> >> at least 312us
> >> +				   for one word transferring.
> >> Becuase of silicon
> >> +				   issue, it MUST check SFIFOL
> >> here instead of
> >> +				   TNF. It is the workaround for
> >> A0 stepping*/
> >
> > wrong comment style.
> 
> I'll fix it.
> 
> >
> >> +				while (--timeout &&
> >> +
> >> ((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
> >> +					udelay(10);
> >> +			}
> >> +			sspc->write(sspc);
> >> +			sspc->read(sspc);
> >> +		}
> >> +	}
> >
> > you can make this look sligthly better if you:
> >
> > if (!sspc->tx)
> > 	bail();
> >
> > while (sspc->tx != sspc->tx_end) {
> > 	if (sspc->timing_wr) {
> > 		int timeout = 100;
> >
> > 		....
> > 	}
> > }
> >
> > it'll decrease one indentation level.
> 
> I'll consider it in next version.
> 
> >
> >> +static void start_bitbanging(struct ssp_drv_context *sspc)
> >
> > I would prefix with ssp_
> 
> That makes sense.
> 
> >
> >> +static int handle_message(struct ssp_drv_context *sspc)
> >> +{
> >> +	struct chip_data *chip = NULL;
> >> +	struct spi_transfer *transfer = NULL;
> >> +	void *reg = sspc->ioaddr;
> >> +	u32 cr1;
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +	struct spi_message *msg = sspc->cur_msg;
> >> +
> >> +	chip = spi_get_ctldata(msg->spi);
> >> +
> >> +	/* We handle only one transfer message since the protocol
> >> module has to
> >> +	   control the out of band signaling. */
> >
> > wrong comment style.
> 
> I'll fix it.
> 
> >
> >> +	transfer = list_entry(msg->transfers.next, struct
> >> spi_transfer,
> >> +					transfer_list);
> >> +
> >> +	/* Check transfer length */
> >> +	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
> >> +		(transfer->len == 0))) {
> >> +		dev_warn(dev, "transfer length null or greater
> >> than %d\n",
> >> +			MAX_SPI_TRANSFER_SIZE);
> >> +		dev_warn(dev, "length = %d\n", transfer->len);
> >> +		msg->status = -EINVAL;
> >> +
> >> +		if (msg->complete)
> >> +			msg->complete(msg->context);
> >> +		complete(&sspc->msg_done);
> >> +		return 0;
> >> +	}
> >> +
> >> +	/* Flush any remaining data (in case of failed previous
> >> transfer) */
> >> +	flush(sspc);
> >> +
> >> +	sspc->tx  = (void *)transfer->tx_buf;
> >> +	sspc->rx  = (void *)transfer->rx_buf;
> >> +	sspc->len = transfer->len;
> >> +	sspc->write = chip->write;
> >> +	sspc->read = chip->read;
> >> +
> >> +	if (likely(chip->dma_enabled)) {
> >> +		sspc->dma_mapped = map_dma_buffers(sspc);
> >> +		if (unlikely(!sspc->dma_mapped))
> >> +			return 0;
> >> +	} else {
> >> +		sspc->write = sspc->tx ? chip->write :
> >> null_writer;
> >> +		sspc->read  = sspc->rx ? chip->read : null_reader;
> >> +	}
> >> +	sspc->tx_end = sspc->tx + transfer->len;
> >> +	sspc->rx_end = sspc->rx + transfer->len;
> >> +	write_SSSR(sspc->clear_sr, reg);
> >> +
> >> +	/* setup the CR1 control register */
> >> +	cr1 = chip->cr1 | sspc->cr1_sig;
> >> +
> >> +	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
> >> +		/* in case of len smaller than burst size, adjust
> >> the RX     */
> >> +		/* threshold. All other cases will use the
> >> default threshold */
> >> +		/* value. The RX fifo threshold must be aligned
> >> with the DMA */
> >> +		/* RX transfer size, which may be limited to a
> >> multiple of 4 */
> >> +		/* bytes due to 32bits DDR
> >> access.                           */
> >
> > wrong comment style
> 
> Ditto
> 
> >
> >> +static int ssp_spi_probe(struct pci_dev *pdev,
> >> +	const struct pci_device_id *ent)
> >> +{
> >> +	struct device *dev = &pdev->dev;
> >> +	struct spi_master *master;
> >> +	struct ssp_drv_context *sspc = 0;
> >> +	int status;
> >> +	u32 iolen = 0;
> >> +	u8 ssp_cfg;
> >> +	int pos;
> >> +	void __iomem *syscfg_ioaddr;
> >> +	unsigned long syscfg;
> >> +
> >> +	/* Check if the SSP we are probed for has been allocated
> >> */
> >> +	/* to operate as SPI. This information is retreived from
> >> */
> >> +	/* the field adid of the Vendor-Specific PCI capability
> >> */
> >> +	/* which is used as a configuration register.
> >> */
> >
> > wrong comment style
> 
> Ditto
> 
> >
> >> +static int ssp_spi_runtime_suspend(struct device *dev)
> >> +{
> >> +	return 0;
> >> +}
> >> +
> >> +static int ssp_spi_runtime_resume(struct device *dev)
> >> +{
> >> +	return 0;
> >> +}
> >
> > why even add these if they're no-ops ?
> 
> I'll remove them.
> 
> >
> >> +static int __init ssp_spi_init(void)
> >> +{
> >> +	return pci_register_driver(&ssp_spi_driver);
> >> +}
> >> +
> >> +late_initcall(ssp_spi_init);
> >
> > does it have to be late ? Can't you just use module_pci_driver()
> > instead ?
> 
> I'll let Ning to answer this.
> 

Agreed. We can use module_pci_driver() here.

> >
> >> @@ -0,0 +1,330 @@
> >> +/*
> >> + *  Copyright (C) Intel 2013
> >> + *
> >> + *
> >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >> + *
> >> + *  This program is free software; you can redistribute it and/or
> >> modify
> >> + *  it under the terms of the GNU General Public License as
> >> published by
> >> + *  the Free Software Foundation; either version 2 of the
> >> License, or
> >> + *  (at your option) any later version.
> >
> > companies usually don't like this "at your option any later version"
> > statement. Usually it's GPL2 only...
> 
> Hm. I've no opinion about. :)
> But I'll make sure this follows the same standard of .c file.
> 
> Br, David
> 

Best Regards,
Ning


^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH 1/2] spi: add Intel Mid SSP driver
@ 2013-10-30  3:26       ` Ning Li
  0 siblings, 0 replies; 36+ messages in thread
From: Ning Li @ 2013-10-30  3:26 UTC (permalink / raw)
  To: David Cohen
  Cc: balbi-l0cyMroinI0, broonie-DgEjT+Ai2ygdnm+yROfE0A,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-spi-u79uwXL29TY76Z2rM5mHXA, Fei Yang

On Tue, 29 Oct 2013 13:18:37 -0700
David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> wrote:

> Hi Felipe,
> 
> On 10/29/2013 11:31 AM, Felipe Balbi wrote:
> > Hi,
> >
> > On Tue, Oct 29, 2013 at 11:05:49AM -0700, David Cohen wrote:
> >> diff --git a/drivers/spi/spi-intel-mid-ssp.c
> >> b/drivers/spi/spi-intel-mid-ssp.c new file mode 100644
> >> index 0000000..b3b9fe8
> >> --- /dev/null
> >> +++ b/drivers/spi/spi-intel-mid-ssp.c
> >> @@ -0,0 +1,1506 @@
> >> +/*
> >> + * spi-intel-mid-ssp.c
> >> + * This driver supports Bulverde SSP core used on Intel MID
> >> platforms
> >> + * It supports SSP of Moorestown & Medfield platforms and handles
> >> clock
> >> + * slave & master modes.
> >> + *
> >> + * Copyright (c) 2013, Intel Corporation.
> >> + * Contacts: Ning Li <ning.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> + *	     David Cohen <david.a.cohen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> >> + *
> >> + * This program is free software; you can redistribute it and/or
> >> modify it
> >> + * under the terms and conditions of the GNU General Public
> >> License,
> >> + * version 2, as published by the Free Software Foundation.
> >> + *
> >> + * This program is distributed in the hope it will be useful, but
> >> WITHOUT
> >> + * ANY WARRANTY; without even the implied warranty of
> >> MERCHANTABILITY or
> >> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
> >> License for
> >> + * more details.
> >> + *
> >> + * You should have received a copy of the GNU General Public
> >> License along with
> >> + * this program; if not, write to the Free Software Foundation,
> >> Inc.,
> >> + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
> >> + *
> >> + */
> >> +
> >> +/*
> >> + * Note:
> >> + *
> >> + * Supports DMA and non-interrupt polled transfers.
> >> + *
> >> + */
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/delay.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/highmem.h>
> >> +#include <linux/pci.h>
> >> +#include <linux/init.h>
> >> +#include <linux/interrupt.h>
> >> +#include <linux/dma-mapping.h>
> >> +#include <linux/intel_mid_dma.h>
> >> +#include <linux/pm_qos.h>
> >> +#include <linux/pm_runtime.h>
> >> +#include <linux/completion.h>
> >> +#include <asm/intel-mid.h>
> >> +
> >> +#include <linux/spi/spi.h>
> >> +#include <linux/spi/intel_mid_ssp_spi.h>
> >> +
> >> +#define DRIVER_NAME "intel_mid_ssp_spi_unified"
> >> +
> >> +static int ssp_timing_wr;
> >
> > this will prevent multiple instances of the same driver.
> 
> Yeah. I'll fix it.
> 
> >
> >> +#ifdef DUMP_RX
> >> +static void dump_trailer(const struct device *dev, char *buf, int
> >> len, int sz) +{
> >> +	int tlen1 = (len < sz ? len : sz);
> >> +	int tlen2 =  ((len - sz) > sz) ? sz : (len - sz);
> >> +	unsigned char *p;
> >> +	static char msg[MAX_SPI_TRANSFER_SIZE];
> >> +
> >> +	memset(msg, '\0', sizeof(msg));
> >> +	p = buf;
> >> +	while (p < buf + tlen1)
> >> +		sprintf(msg, "%s%02x", msg, (unsigned int)*p++);
> >> +
> >> +	if (tlen2 > 0) {
> >> +		sprintf(msg, "%s .....", msg);
> >> +		p = (buf+len) - tlen2;
> >> +		while (p < buf + len)
> >> +			sprintf(msg, "%s%02x", msg, (unsigned
> >> int)*p++);
> >> +	}
> >> +
> >> +	dev_info(dev, "DUMP: %p[0:%d ... %d:%d]:%s", buf, tlen1 -
> >> 1,
> >> +		   len-tlen2, len - 1, msg);
> >> +}
> >> +#endif
> >
> > either move this to debugfs or stub the function out ifndef DUMP_RX,
> > then you don't need the ifdefs when calling it.
> 
> Agreed.
> 
> >
> >> +static inline u8 ssp_cfg_get_mode(u8 ssp_cfg)
> >> +{
> >> +	if (intel_mid_identify_cpu() ==
> >> INTEL_MID_CPU_CHIP_TANGIER)
> >
> > instead, couldn't you use driver data to pass some flags to the
> > driver ? I can't see intel_mid_identify_cpu and having drivers
> > depend on arch-specific code is usually a bad practice.
> 
> I'll find a way to get rid of this.
> 
> >
> >> +		return (ssp_cfg) & 0x03;
> >> +	else
> >
> > else isn't needed here
> 
> Agreed.
> 
> >
> >> +static inline u32 is_tx_fifo_empty(struct ssp_drv_context *sspc)
> >> +{
> >> +	u32 sssr;
> >
> > blank line here would aid readability
> >
> 
> Agreed.
> 
> >> +	sssr = read_SSSR(sspc->ioaddr);
> >> +	if ((sssr & SSSR_TFL_MASK) || (sssr & SSSR_TNF) == 0)
> >> +		return 0;
> >> +	else
> >
> > else isn't necessary
> 
> Agreed.
> 
> >
> >> +static inline u32 is_rx_fifo_empty(struct ssp_drv_context *sspc)
> >> +{
> >> +	return ((read_SSSR(sspc->ioaddr) & SSSR_RNE) == 0);
> >
> > you don't need the outter parenthesis here, GCC should've warned
> > you, even.
> 
> Yeah. checkpatch supposed to warn too. I'll fix it.
> 
> >
> >> +static inline void disable_interface(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line here
> >
> >> +	write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
> >> +}
> >> +
> >> +static inline void disable_triggers(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > and here...
> >
> >> +	write_SSCR1(read_SSCR1(reg) & ~sspc->cr1_sig, reg);
> >> +}
> >> +
> >> +
> >> +static void flush(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >> +	u32 i = 0;
> >> +
> >> +	/* If the transmit fifo is not empty, reset the
> >> interface. */
> >> +	if (!is_tx_fifo_empty(sspc)) {
> >> +		dev_err(&sspc->pdev->dev, "TX FIFO not empty.
> >> Reset of SPI IF");
> >> +		disable_interface(sspc);
> >> +		return;
> >> +	}
> >
> > not so sure, if the transmit fifo isn't empty and you reset it, you
> > could end up corrupting data which is about to be shifted into the
> > wire, couldn't you ?
> >
> > Is this a case which would *really* happen in normal conditions ?
> > If so, why ?
> 
> I'll leave this question to Ning.

I did not see it happen before, but maybe the previous author had met
the situation. Actually, it should be safe to disable the port here,
since when setting SSCR.SSE bit to 0, the SSP will be disabled and at
the same time, the FIFOs will be cleared, according to the spec.

> 
> >
> >> +	dev_dbg(&sspc->pdev->dev, " SSSR=%x\r\n", read_SSSR(reg));
> >> +	while (!is_rx_fifo_empty(sspc) && (i < SPI_FIFO_SIZE +
> >> 1)) {
> >> +		read_SSDR(reg);
> >> +		i++;
> >> +	}
> >> +	WARN(i > 0, "%d words flush occured\n", i);
> >
> > similarly, you could be ignoring data you *should* indeed be
> > handling.
> 
> That seems the case, yes.
> 
> >
> >> +
> >> +	return;
> >
> > return statement is unnecessary.
> 
> Agreed.
> 
> >
> >> +static int null_writer(struct ssp_drv_context *sspc)
> >
> > looks like these two functions (null_\(writer\|reader\)) need some
> > documentation. Why do they exist ?
> 
> I'll make sure next version has comments for it.
> 
> >
> >> +static int u8_writer(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> >> +		|| (sspc->tx == sspc->tx_end))
> >> +		return 0;
> >> +
> >> +	write_SSDR(*(u8 *)(sspc->tx), reg);
> >> +	++sspc->tx;
> >> +
> >> +	return 1;
> >> +}
> >> +
> >> +static int u8_reader(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	while ((read_SSSR(reg) & SSSR_RNE)
> >> +		&& (sspc->rx < sspc->rx_end)) {
> >> +		*(u8 *)(sspc->rx) = read_SSDR(reg);
> >> +		++sspc->rx;
> >> +	}
> >> +
> >> +	return sspc->rx == sspc->rx_end;
> >> +}
> >> +
> >> +static int u16_writer(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> >
> > the extra comparisson here is superfluous.
> 
> Agreed.
> 
> >
> >> +		|| (sspc->tx == sspc->tx_end))
> >> +		return 0;
> >> +
> >> +	write_SSDR(*(u16 *)(sspc->tx), reg);
> >> +	sspc->tx += 2;
> >> +
> >> +	return 1;
> >> +}
> >> +
> >> +static int u16_reader(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx <
> >> sspc->rx_end)) {
> >> +		*(u16 *)(sspc->rx) = read_SSDR(reg);
> >> +		sspc->rx += 2;
> >> +	}
> >> +
> >> +	return sspc->rx == sspc->rx_end;
> >> +}
> >> +
> >> +static int u32_writer(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
> >
> > the extra comparisson here is superfluous.
> 
> Agreed.
> 
> >
> >> +		|| (sspc->tx == sspc->tx_end))
> >> +		return 0;
> >> +
> >> +	write_SSDR(*(u32 *)(sspc->tx), reg);
> >> +	sspc->tx += 4;
> >> +
> >> +	return 1;
> >> +}
> >> +
> >> +static int u32_reader(struct ssp_drv_context *sspc)
> >> +{
> >> +	void *reg = sspc->ioaddr;
> >
> > blank line
> >
> >> +	while ((read_SSSR(reg) & SSSR_RNE) && (sspc->rx <
> >> sspc->rx_end)) {
> >> +		*(u32 *)(sspc->rx) = read_SSDR(reg);
> >> +		sspc->rx += 4;
> >> +	}
> >> +
> >> +	return sspc->rx == sspc->rx_end;
> >> +}
> >> +
> >> +static bool chan_filter(struct dma_chan *chan, void *param)
> >> +{
> >> +	struct ssp_drv_context *sspc = param;
> >> +
> >> +	if (sspc->dmac1 && chan->device->dev == &sspc->dmac1->dev)
> >> +		return true;
> >> +
> >> +	return false;
> >> +}
> >> +
> >> +/**
> >> + * unmap_dma_buffers() - Unmap the DMA buffers used during the
> >> last transfer.
> >> + * @sspc:	Pointer to the private driver context
> >> + */
> >> +static void unmap_dma_buffers(struct ssp_drv_context *sspc)
> >> +{
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +
> >> +	if (!sspc->dma_mapped)
> >> +		return;
> >
> > blank line
> >
> >> +	dma_unmap_single(dev, sspc->rx_dma, sspc->len,
> >> PCI_DMA_FROMDEVICE);
> >> +	dma_unmap_single(dev, sspc->tx_dma, sspc->len,
> >> PCI_DMA_TODEVICE);
> >> +	sspc->dma_mapped = 0;
> >
> > you shouldn't need this dma_mapped flag here...
> >
> >> +static void ssp_spi_dma_done(void *arg)
> >> +{
> >> +	struct callback_param *cb_param = (struct callback_param
> >> *)arg;
> >> +	struct ssp_drv_context *sspc = cb_param->drv_context;
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +	void *reg = sspc->ioaddr;
> >> +
> >> +	if (cb_param->direction == TX_DIRECTION)
> >> +		sspc->txdma_done = 1;
> >> +	else
> >> +		sspc->rxdma_done = 1;
> >> +
> >> +	dev_dbg(dev, "DMA callback for direction %d [RX done:%d]
> >> [TX done:%d]\n",
> >> +		cb_param->direction, sspc->rxdma_done,
> >> +		sspc->txdma_done);
> >> +
> >> +	if (sspc->txdma_done && sspc->rxdma_done) {
> >> +		/* Clear Status Register */
> >> +		write_SSSR(sspc->clear_sr, reg);
> >> +		dev_dbg(dev, "DMA done\n");
> >> +		/* Disable Triggers to DMA or to CPU*/
> >> +		disable_triggers(sspc);
> >> +		unmap_dma_buffers(sspc);
> >> +
> >> +		queue_work(sspc->dma_wq, &sspc->complete_work);
> >
> > I fail to see the need for this workstruct, why can't you call
> > complete() directly ?
> >
> >> +static irqreturn_t ssp_int(int irq, void *dev_id)
> >> +{
> >> +	struct ssp_drv_context *sspc = dev_id;
> >> +	void *reg = sspc->ioaddr;
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +	u32 status = read_SSSR(reg);
> >> +
> >> +	/* It should never be our interrupt since SSP will */
> >> +	/* only trigs interrupt for under/over run.        */
> >
> > wrong comment style
> 
> I'll fix it
> 
> >
> >> +	if (likely(!(status & sspc->mask_sr)))
> >> +		return IRQ_NONE;
> >> +
> >> +	if (status & SSSR_ROR || status & SSSR_TUR) {
> >> +		dev_err(dev, "--- SPI ROR or TUR occurred :
> >> SSSR=%x\n",	status);
> >> +		WARN_ON(1);
> >> +		if (status & SSSR_ROR)
> >> +			dev_err(dev, "we have Overrun\n");
> >> +		if (status & SSSR_TUR)
> >> +			dev_err(dev, "we have Underrun\n");
> >> +	}
> >
> > I would split these two caes here:
> >
> > if (status & ROR)
> > 	dev_WARN(dev, "Overrun\n");
> >
> > if (status & TUR)
> > 	dev_WARN(dev, "Underrun\n");
> >
> > no need for nested ifs.
> 
> Agreed.
> 
> >
> >> +static void poll_transfer(unsigned long data)
> >> +{
> >> +	struct ssp_drv_context *sspc = (void *)data;
> >> +
> >> +	if (sspc->tx) {
> >> +		while (sspc->tx != sspc->tx_end) {
> >> +			if (ssp_timing_wr) {
> >> +				int timeout = 100;
> >> +				/* It is used as debug UART on
> >> Tangier. Since
> >> +				   baud rate = 115200, it needs
> >> at least 312us
> >> +				   for one word transferring.
> >> Becuase of silicon
> >> +				   issue, it MUST check SFIFOL
> >> here instead of
> >> +				   TNF. It is the workaround for
> >> A0 stepping*/
> >
> > wrong comment style.
> 
> I'll fix it.
> 
> >
> >> +				while (--timeout &&
> >> +
> >> ((read_SFIFOL(sspc->ioaddr)) & 0xFFFF))
> >> +					udelay(10);
> >> +			}
> >> +			sspc->write(sspc);
> >> +			sspc->read(sspc);
> >> +		}
> >> +	}
> >
> > you can make this look sligthly better if you:
> >
> > if (!sspc->tx)
> > 	bail();
> >
> > while (sspc->tx != sspc->tx_end) {
> > 	if (sspc->timing_wr) {
> > 		int timeout = 100;
> >
> > 		....
> > 	}
> > }
> >
> > it'll decrease one indentation level.
> 
> I'll consider it in next version.
> 
> >
> >> +static void start_bitbanging(struct ssp_drv_context *sspc)
> >
> > I would prefix with ssp_
> 
> That makes sense.
> 
> >
> >> +static int handle_message(struct ssp_drv_context *sspc)
> >> +{
> >> +	struct chip_data *chip = NULL;
> >> +	struct spi_transfer *transfer = NULL;
> >> +	void *reg = sspc->ioaddr;
> >> +	u32 cr1;
> >> +	struct device *dev = &sspc->pdev->dev;
> >> +	struct spi_message *msg = sspc->cur_msg;
> >> +
> >> +	chip = spi_get_ctldata(msg->spi);
> >> +
> >> +	/* We handle only one transfer message since the protocol
> >> module has to
> >> +	   control the out of band signaling. */
> >
> > wrong comment style.
> 
> I'll fix it.
> 
> >
> >> +	transfer = list_entry(msg->transfers.next, struct
> >> spi_transfer,
> >> +					transfer_list);
> >> +
> >> +	/* Check transfer length */
> >> +	if (unlikely((transfer->len > MAX_SPI_TRANSFER_SIZE) ||
> >> +		(transfer->len == 0))) {
> >> +		dev_warn(dev, "transfer length null or greater
> >> than %d\n",
> >> +			MAX_SPI_TRANSFER_SIZE);
> >> +		dev_warn(dev, "length = %d\n", transfer->len);
> >> +		msg->status = -EINVAL;
> >> +
> >> +		if (msg->complete)
> >> +			msg->complete(msg->context);
> >> +		complete(&sspc->msg_done);
> >> +		return 0;
> >> +	}
> >> +
> >> +	/* Flush any remaining data (in case of failed previous
> >> transfer) */
> >> +	flush(sspc);
> >> +
> >> +	sspc->tx  = (void *)transfer->tx_buf;
> >> +	sspc->rx  = (void *)transfer->rx_buf;
> >> +	sspc->len = transfer->len;
> >> +	sspc->write = chip->write;
> >> +	sspc->read = chip->read;
> >> +
> >> +	if (likely(chip->dma_enabled)) {
> >> +		sspc->dma_mapped = map_dma_buffers(sspc);
> >> +		if (unlikely(!sspc->dma_mapped))
> >> +			return 0;
> >> +	} else {
> >> +		sspc->write = sspc->tx ? chip->write :
> >> null_writer;
> >> +		sspc->read  = sspc->rx ? chip->read : null_reader;
> >> +	}
> >> +	sspc->tx_end = sspc->tx + transfer->len;
> >> +	sspc->rx_end = sspc->rx + transfer->len;
> >> +	write_SSSR(sspc->clear_sr, reg);
> >> +
> >> +	/* setup the CR1 control register */
> >> +	cr1 = chip->cr1 | sspc->cr1_sig;
> >> +
> >> +	if (likely(sspc->quirks & QUIRKS_DMA_USE_NO_TRAIL)) {
> >> +		/* in case of len smaller than burst size, adjust
> >> the RX     */
> >> +		/* threshold. All other cases will use the
> >> default threshold */
> >> +		/* value. The RX fifo threshold must be aligned
> >> with the DMA */
> >> +		/* RX transfer size, which may be limited to a
> >> multiple of 4 */
> >> +		/* bytes due to 32bits DDR
> >> access.                           */
> >
> > wrong comment style
> 
> Ditto
> 
> >
> >> +static int ssp_spi_probe(struct pci_dev *pdev,
> >> +	const struct pci_device_id *ent)
> >> +{
> >> +	struct device *dev = &pdev->dev;
> >> +	struct spi_master *master;
> >> +	struct ssp_drv_context *sspc = 0;
> >> +	int status;
> >> +	u32 iolen = 0;
> >> +	u8 ssp_cfg;
> >> +	int pos;
> >> +	void __iomem *syscfg_ioaddr;
> >> +	unsigned long syscfg;
> >> +
> >> +	/* Check if the SSP we are probed for has been allocated
> >> */
> >> +	/* to operate as SPI. This information is retreived from
> >> */
> >> +	/* the field adid of the Vendor-Specific PCI capability
> >> */
> >> +	/* which is used as a configuration register.
> >> */
> >
> > wrong comment style
> 
> Ditto
> 
> >
> >> +static int ssp_spi_runtime_suspend(struct device *dev)
> >> +{
> >> +	return 0;
> >> +}
> >> +
> >> +static int ssp_spi_runtime_resume(struct device *dev)
> >> +{
> >> +	return 0;
> >> +}
> >
> > why even add these if they're no-ops ?
> 
> I'll remove them.
> 
> >
> >> +static int __init ssp_spi_init(void)
> >> +{
> >> +	return pci_register_driver(&ssp_spi_driver);
> >> +}
> >> +
> >> +late_initcall(ssp_spi_init);
> >
> > does it have to be late ? Can't you just use module_pci_driver()
> > instead ?
> 
> I'll let Ning to answer this.
> 

Agreed. We can use module_pci_driver() here.

> >
> >> @@ -0,0 +1,330 @@
> >> +/*
> >> + *  Copyright (C) Intel 2013
> >> + *
> >> + *
> >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >> + *
> >> + *  This program is free software; you can redistribute it and/or
> >> modify
> >> + *  it under the terms of the GNU General Public License as
> >> published by
> >> + *  the Free Software Foundation; either version 2 of the
> >> License, or
> >> + *  (at your option) any later version.
> >
> > companies usually don't like this "at your option any later version"
> > statement. Usually it's GPL2 only...
> 
> Hm. I've no opinion about. :)
> But I'll make sure this follows the same standard of .c file.
> 
> Br, David
> 

Best Regards,
Ning

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^ permalink raw reply	[flat|nested] 36+ messages in thread

* [PATCH V2] checkpatch: Improve "return is not a function" test
  2013-10-29 19:38           ` Joe Perches
  (?)
  (?)
@ 2013-10-31 23:12           ` Joe Perches
  2013-11-01  1:03             ` David Cohen
  2013-11-04 22:21             ` Andrew Morton
  -1 siblings, 2 replies; 36+ messages in thread
From: Joe Perches @ 2013-10-31 23:12 UTC (permalink / raw)
  To: Andrew Morton, Andy Whitcroft; +Cc: David Cohen, linux-kernel

Find a few more cases where parentheses are used around
the value of a return statement.

This now uses the "$balanced_parens" test and also makes
the test depend on perl v5.10 and higher.

This now finds return with parenthesis uses the old code
did not find like:

ERROR: return is not a function, parentheses are not required
#211: FILE: arch/m68k/include/asm/sun3xflop.h:211:
+		return ((error == 0) ? 0 : -1);

Signed-off-by: Joe Perches <joe@perches.com>
---

V2: Add example to commit message.
    No change in patch itself.

 scripts/checkpatch.pl | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 23d55bf..957ba04 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3221,21 +3221,10 @@ sub process {
 		}
 
 # Return is not a function.
-		if (defined($stat) && $stat =~ /^.\s*return(\s*)(\(.*);/s) {
+		if (defined($stat) && $stat =~ /^.\s*return(\s*)\(/s) {
 			my $spacing = $1;
-			my $value = $2;
-
-			# Flatten any parentheses
-			$value =~ s/\(/ \(/g;
-			$value =~ s/\)/\) /g;
-			while ($value =~ s/\[[^\[\]]*\]/1/ ||
-			       $value !~ /(?:$Ident|-?$Constant)\s*
-					     $Compare\s*
-					     (?:$Ident|-?$Constant)/x &&
-			       $value =~ s/\([^\(\)]*\)/1/) {
-			}
-#print "value<$value>\n";
-			if ($value =~ /^\s*(?:$Ident|-?$Constant)\s*$/) {
+			if ($^V && $^V ge 5.10.0 &&
+			    $stat =~ /^.\s*return\s*$balanced_parens\s*;\s*$/) {
 				ERROR("RETURN_PARENTHESES",
 				      "return is not a function, parentheses are not required\n" . $herecurr);
 
@@ -3244,6 +3233,7 @@ sub process {
 				      "space required before the open parenthesis '('\n" . $herecurr);
 			}
 		}
+
 # Return of what appears to be an errno should normally be -'ve
 		if ($line =~ /^.\s*return\s*(E[A-Z]*)\s*;/) {
 			my $name = $1;




^ permalink raw reply related	[flat|nested] 36+ messages in thread

* Re: [PATCH V2] checkpatch: Improve "return is not a function" test
  2013-10-31 23:12           ` [PATCH V2] " Joe Perches
@ 2013-11-01  1:03             ` David Cohen
  2013-11-04 22:21             ` Andrew Morton
  1 sibling, 0 replies; 36+ messages in thread
From: David Cohen @ 2013-11-01  1:03 UTC (permalink / raw)
  To: Joe Perches; +Cc: Andrew Morton, Andy Whitcroft, linux-kernel

On 10/31/2013 04:12 PM, Joe Perches wrote:
> Find a few more cases where parentheses are used around
> the value of a return statement.
> 
> This now uses the "$balanced_parens" test and also makes
> the test depend on perl v5.10 and higher.
> 
> This now finds return with parenthesis uses the old code
> did not find like:
> 
> ERROR: return is not a function, parentheses are not required
> #211: FILE: arch/m68k/include/asm/sun3xflop.h:211:
> +		return ((error == 0) ? 0 : -1);
> 
> Signed-off-by: Joe Perches <joe@perches.com>

It catches the previous false-negative I had.

Acked-by: David Cohen <david.a.cohen@linux.intel.com>

^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH V2] checkpatch: Improve "return is not a function" test
  2013-10-31 23:12           ` [PATCH V2] " Joe Perches
  2013-11-01  1:03             ` David Cohen
@ 2013-11-04 22:21             ` Andrew Morton
  2013-11-04 22:24               ` Joe Perches
  1 sibling, 1 reply; 36+ messages in thread
From: Andrew Morton @ 2013-11-04 22:21 UTC (permalink / raw)
  To: Joe Perches; +Cc: Andy Whitcroft, David Cohen, linux-kernel

On Thu, 31 Oct 2013 16:12:44 -0700 Joe Perches <joe@perches.com> wrote:

> This now uses the "$balanced_parens" test and also makes
> the test depend on perl v5.10 and higher.

What happens if one uses an older perl version?  A mysterious-looking
splat, I assume?

It would be nicer to have some explicit perl version test which tells
user what the problem is, and which perl version is needed?


^ permalink raw reply	[flat|nested] 36+ messages in thread

* Re: [PATCH V2] checkpatch: Improve "return is not a function" test
  2013-11-04 22:21             ` Andrew Morton
@ 2013-11-04 22:24               ` Joe Perches
  0 siblings, 0 replies; 36+ messages in thread
From: Joe Perches @ 2013-11-04 22:24 UTC (permalink / raw)
  To: Andrew Morton; +Cc: Andy Whitcroft, David Cohen, linux-kernel

On Mon, 2013-11-04 at 14:21 -0800, Andrew Morton wrote:
> On Thu, 31 Oct 2013 16:12:44 -0700 Joe Perches <joe@perches.com> wrote:
> 
> > This now uses the "$balanced_parens" test and also makes
> > the test depend on perl v5.10 and higher.
> 
> What happens if one uses an older perl version?  A mysterious-looking
> splat, I assume?
> 
> It would be nicer to have some explicit perl version test which tells
> user what the problem is, and which perl version is needed?
> 

There is such a test already.
You Signed-off on it.

commit d62a201f24cba74e2fbf9f6f7af86ff5f5e276fc
Author: Dave Hansen <dave.hansen@linux.intel.com>
Date:   Wed Sep 11 14:23:56 2013 -0700

    checkpatch: enforce sane perl version
    
    I got a bug report from a couple of users who said checkpatch.pl was
    broken for them.  It was erroring out on fairly random lines most commonly
    with messages like:
    
        Nested quantifiers in regex; marked by <--HERE in m/(\((?:[^\(\)]++ <-
    
    The bug reporter was running a version of perl 5.8 which was end-of-lifed
    in 2008: http://www.cpan.org/src/.  Versions of perl this old are at
    _best_ quite untested.  At worst, they are crusty and known to be
    completely broken.
    
    If folks have a system _that_ old, then we should have mercy on them and
    give them a half-decent error message rather than fail with nutty error
    messages.
    
    This patch enforces that checkpatch.pl is run with perl 5.10, which was
    end-of-lifed in 2009.  The new --ignore-perl-version command-line switch
    will let folks override this if they want.
    
    Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: Joe Perches <joe@perches.com>
    Cc: Andy Whitcroft <apw@shadowen.org>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>



^ permalink raw reply	[flat|nested] 36+ messages in thread

end of thread, other threads:[~2013-11-04 22:24 UTC | newest]

Thread overview: 36+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-10-29 18:05 [PATCH 1/2] spi: add Intel Mid SSP driver David Cohen
2013-10-29 18:05 ` [PATCH 2/2] MAINTAINERS: add Intel MID SSP SPI maintainers David Cohen
2013-10-29 18:05   ` David Cohen
2013-10-29 18:20   ` Joe Perches
2013-10-29 18:33     ` David Cohen
2013-10-29 18:33       ` David Cohen
2013-10-29 18:57   ` Mark Brown
2013-10-29 18:19 ` [PATCH 1/2] spi: add Intel Mid SSP driver Joe Perches
2013-10-29 18:30   ` David Cohen
2013-10-29 18:35     ` Joe Perches
2013-10-29 18:35       ` Joe Perches
2013-10-29 19:32       ` David Cohen
2013-10-29 19:32         ` David Cohen
2013-10-29 19:38         ` Joe Perches
2013-10-29 19:38           ` Joe Perches
2013-10-29 20:28           ` [PATCH] checkpatch: Improve "return is not a function" test Joe Perches
2013-10-31 23:12           ` [PATCH V2] " Joe Perches
2013-11-01  1:03             ` David Cohen
2013-11-04 22:21             ` Andrew Morton
2013-11-04 22:24               ` Joe Perches
2013-10-29 18:29 ` [PATCH 1/2] spi: add Intel Mid SSP driver Randy Dunlap
2013-10-29 18:29   ` Randy Dunlap
2013-10-29 18:35   ` David Cohen
2013-10-29 18:35     ` David Cohen
2013-10-29 18:31 ` Felipe Balbi
2013-10-29 18:31   ` Felipe Balbi
2013-10-29 20:18   ` David Cohen
2013-10-29 20:18     ` David Cohen
2013-10-30  3:26     ` Ning Li
2013-10-30  3:26       ` Ning Li
2013-10-29 18:56 ` Mark Brown
2013-10-29 18:56   ` Mark Brown
2013-10-29 20:08   ` David Cohen
2013-10-29 20:08     ` David Cohen
2013-10-30  1:42 ` Randy Dunlap
2013-10-30  1:42   ` Randy Dunlap

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