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* [PATCH] Freescale STMP spi driver
@ 2009-06-02 19:40 dmitry pervushin
       [not found] ` <1243971638.4011.16.camel-GL0tbJR47UuzLY3athcO2A@public.gmane.org>
  0 siblings, 1 reply; 9+ messages in thread
From: dmitry pervushin @ 2009-06-02 19:40 UTC (permalink / raw)
  To: David Brownell; +Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f

Hello David,

Here is the patch for SSP/SPI on STMP3xxx boards; could you please apply
it? Any comments are appreciated.
=========================================================================

The patch adds support of SSP ports in SPI mode on Freescale STMP3xxx
platforms.

Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>

Index: linux-2.6-arm/drivers/spi/Kconfig
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Kconfig
+++ linux-2.6-arm/drivers/spi/Kconfig
@@ -204,6 +204,12 @@ config SPI_SH_SCI
 	help
 	  SPI driver for SuperH SCI blocks.
 
+config SPI_STMP3XXX
+	tristate "Freescale STMP37xx/378x SPI/SSP controller"
+	depends on ARCH_STMP3XXX && SPI_MASTER
+	help
+	  SPI driver for Freescale STMP37xx/378x SoC SSP interface
+
 config SPI_TXX9
 	tristate "Toshiba TXx9 SPI controller"
 	depends on GENERIC_GPIO && CPU_TX49XX
Index: linux-2.6-arm/drivers/spi/Makefile
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Makefile
+++ linux-2.6-arm/drivers/spi/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24x
 obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
+obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
Index: linux-2.6-arm/drivers/spi/spi_stmp.c
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/spi/spi_stmp.c
@@ -0,0 +1,655 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-ssp.h>
+#include <mach/regs-apbh.h>
+#include "spi_stmp.h"
+
+/* 0 means DMA mode(recommended, default), !0 - PIO mode */
+static int pio;
+static int debug;
+static int clock;
+
+#define busy_wait(cond)						\
+	({							\
+	  int count;						\
+	  for (count = 1000; (cond) && count > 0; count--)	\
+		  cpu_relax();					\
+	  (count);						\
+	})
+
+
+
+/**
+ * stmp_spi_init_hw
+ * Initialize the SSP port
+ */
+static int stmp_spi_init_hw(struct stmp_spi *ss)
+{
+	int err = 0;
+	void *pins = ss->master_dev->platform_data;
+
+	err = stmp3xxx_request_pin_group(pins, dev_name(ss->master_dev));
+	if (err)
+		goto out;
+
+	ss->clk = clk_get(NULL, "ssp");
+	if (IS_ERR(ss->clk)) {
+		err = PTR_ERR(ss->clk);
+		goto out_free_pins;
+	}
+	clk_enable(ss->clk);
+
+	stmp3xxx_reset_block(ss->regs, false);
+	stmp3xxx_dma_reset_channel(ss->dma);
+
+	return 0;
+
+out_free_pins:
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+out:
+	return err;
+}
+
+static void stmp_spi_release_hw(struct stmp_spi *ss)
+{
+	void *pins = ss->master_dev->platform_data;
+
+	if (ss->clk && !IS_ERR(ss->clk)) {
+		clk_disable(ss->clk);
+		clk_put(ss->clk);
+	}
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+}
+
+static int stmp_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	u8 bits_per_word;
+	u32 hz;
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	u16 rate;
+
+	bits_per_word = spi->bits_per_word;
+	if (t && t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+
+	/*
+	  Calculate speed:
+		- by default, use maximum speed from ssp clk
+		- if device overrides it, use it
+		- if transfer specifies other speed, use transfer's one
+	 */
+	hz = 1000 * ss->speed_khz / ss->divider;
+	if (spi->max_speed_hz)
+		hz = min(hz, spi->max_speed_hz);
+	if (t && t->speed_hz)
+		hz = min(hz, t->speed_hz);
+
+	if (hz == 0) {
+		dev_err(&spi->dev, "Cannot continue with zero clock\n");
+		return -EINVAL;
+	}
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
+		hz, ss->speed_khz, ss->divider,
+		ss->speed_khz * 1000 / ss->divider);
+
+	if (ss->speed_khz * 1000 / ss->divider < hz) {
+		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
+			__func__, hz);
+		return -EINVAL;
+	}
+
+	rate = 1000 * ss->speed_khz/ss->divider/hz;
+
+	writel(BF(ss->divider, SSP_TIMING_CLOCK_DIVIDE)		|
+	       BF(rate - 1, SSP_TIMING_CLOCK_RATE),
+	       HW_SSP_TIMING + ss->regs);
+
+	writel(BF(1 /* mode SPI */, SSP_CTRL1_SSP_MODE)		|
+	       BF(4 /* 8 bits   */, SSP_CTRL1_WORD_LENGTH)	|
+	       ((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
+	       ((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
+	       (pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE),
+	       ss->regs + HW_SSP_CTRL1);
+
+	return 0;
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA)
+static int stmp_spi_setup(struct spi_device *spi)
+{
+	struct stmp_spi *ss;
+
+	ss = spi_master_get_devdata(spi->master);
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+	if (spi->mode & ~MODEBITS) {
+		dev_err(&spi->dev, "%s: unsupported mode bits %x\n",
+			__func__, spi->mode & ~MODEBITS);
+		return -EINVAL;
+	}
+	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w\n",
+		__func__, spi->mode & MODEBITS, spi->bits_per_word);
+	return stmp_spi_setup_transfer(spi, NULL);
+}
+
+static inline u32 stmp_spi_cs(unsigned cs)
+{
+	return  ((cs & 1) ? BM_SSP_CTRL0_WAIT_FOR_CMD : 0) |
+		((cs & 2) ? BM_SSP_CTRL0_WAIT_FOR_IRQ : 0);
+}
+
+static int stmp_spi_txrx_dma(struct stmp_spi *ss, int cs,
+		unsigned char *buf, dma_addr_t dma_buf, int len,
+		int *first, int *last, int write)
+{
+	u32 c0 = 0;
+	dma_addr_t spi_buf_dma = dma_buf;
+	int status = 0;
+	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	c0 |= (*first ? BM_SSP_CTRL0_LOCK_CS : 0);
+	c0 |= (*last ? BM_SSP_CTRL0_IGNORE_CRC : 0);
+	c0 |= (write ? 0 : BM_SSP_CTRL0_READ);
+	c0 |= BM_SSP_CTRL0_DATA_XFER;
+
+	c0 |= stmp_spi_cs(cs);
+
+	c0 |= BF(len, SSP_CTRL0_XFER_COUNT);
+
+	if (!dma_buf)
+		spi_buf_dma = dma_map_single(ss->master_dev, buf, len, dir);
+
+	ss->d.command->cmd =
+		BF(len, APBH_CHn_CMD_XFER_COUNT)	|
+		BF(1, APBH_CHn_CMD_CMDWORDS)		|
+		BM_APBH_CHn_CMD_WAIT4ENDCMD		|
+		BM_APBH_CHn_CMD_IRQONCMPLT		|
+		BF(write ? BV_APBH_CHn_CMD_COMMAND__DMA_READ :
+			   BV_APBH_CHn_CMD_COMMAND__DMA_WRITE,
+		   APBH_CHn_CMD_COMMAND);
+	ss->d.command->pio_words[0] = c0;
+	ss->d.command->buf_ptr = spi_buf_dma;
+
+	stmp3xxx_dma_reset_channel(ss->dma);
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	stmp3xxx_dma_enable_interrupt(ss->dma);
+	init_completion(&ss->done);
+	stmp3xxx_dma_go(ss->dma, &ss->d, 1);
+	wait_for_completion(&ss->done);
+
+	if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) & BM_SSP_CTRL0_RUN) == 0)
+		status = ETIMEDOUT;
+
+	if (!dma_buf)
+		dma_unmap_single(ss->master_dev, spi_buf_dma, len, dir);
+
+	return status;
+}
+
+static inline void stmp_spi_enable(struct stmp_spi *ss)
+{
+	stmp3xxx_setl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_clearl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static inline void stmp_spi_disable(struct stmp_spi *ss)
+{
+	stmp3xxx_clearl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_setl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static int stmp_spi_txrx_pio(struct stmp_spi *ss, int cs,
+		unsigned char *buf, int len,
+		int *first, int *last, int write)
+{
+	if (*first) {
+		stmp_spi_enable(ss);
+		*first = 0;
+	}
+
+	stmp3xxx_setl(stmp_spi_cs(cs), ss->regs + HW_SSP_CTRL0);
+
+	while (len--) {
+		if (*last && len == 0) {
+			stmp_spi_disable(ss);
+			*last = 0;
+		}
+
+		stmp3xxx_clearl(BM_SSP_CTRL0_XFER_COUNT,
+				ss->regs + HW_SSP_CTRL0);
+		stmp3xxx_setl(1, ss->regs + HW_SSP_CTRL0);
+
+		if (write)
+			stmp3xxx_clearl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+		else
+			stmp3xxx_setl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+
+		/* Run! */
+		stmp3xxx_setl(BM_SSP_CTRL0_RUN, ss->regs + HW_SSP_CTRL0);
+
+		if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+				BM_SSP_CTRL0_RUN) == 0)
+			break;
+
+		if (write)
+			writel(*buf, ss->regs + HW_SSP_DATA);
+
+		/* Set TRANSFER */
+		stmp3xxx_setl(BM_SSP_CTRL0_DATA_XFER, ss->regs + HW_SSP_CTRL0);
+
+		if (!write) {
+			if (!busy_wait((readl(ss->regs + HW_SSP_STATUS) &
+					BM_SSP_STATUS_FIFO_EMPTY) == 0))
+				break;
+			*buf = readl(ss->regs + HW_SSP_DATA) & 0xFF;
+		}
+
+		if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+					BM_SSP_CTRL0_RUN) == 0)
+			break;
+
+		/* advance to the next byte */
+		buf++;
+	}
+	return len < 0 ? 0 : -ETIMEDOUT;
+}
+
+static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
+{
+	int first, last;
+	struct spi_transfer *t, *tmp_t;
+	int status = 0;
+	int cs;
+
+	first = last = 0;
+
+	cs = m->spi->chip_select;
+
+	list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
+
+		stmp_spi_setup_transfer(m->spi, t);
+
+		if (&t->transfer_list == m->transfers.next)
+			first = !0;
+		if (&t->transfer_list == m->transfers.prev)
+			last = !0;
+		if (t->rx_buf && t->tx_buf) {
+			pr_debug("%s: cannot send and receive simultaneously\n",
+				__func__);
+			return -EINVAL;
+		}
+
+		/*
+		  REVISIT:
+		  here driver completely ignores setting of t->cs_change
+		 */
+		if (t->tx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
+				   t->len, &first, &last, 1) :
+			   stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
+				   t->tx_dma, t->len, &first, &last, 1);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Tx ",
+						DUMP_PREFIX_OFFSET,
+						t->tx_buf, t->len);
+				else
+					pr_debug("Tx: %d bytes\n", t->len);
+			}
+		}
+		if (t->rx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, t->rx_buf,
+				   t->len, &first, &last, 0) :
+			   stmp_spi_txrx_dma(ss, cs, t->rx_buf,
+				   t->rx_dma, t->len, &first, &last, 0);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Rx ",
+						DUMP_PREFIX_OFFSET,
+						t->rx_buf, t->len);
+				else
+					pr_debug("Rx: %d bytes\n", t->len);
+			}
+		}
+
+		if (status)
+			break;
+
+		first = last = 0;
+
+	}
+	return status;
+}
+
+/**
+ * stmp_spi_handle - handle messages from the queue
+ */
+static void stmp_spi_handle(struct work_struct *w)
+{
+	struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
+	unsigned long flags;
+	struct spi_message *m;
+
+	BUG_ON(w == NULL);
+
+	spin_lock_irqsave(&ss->lock, flags);
+	while (!list_empty(&ss->queue)) {
+		m = list_entry(ss->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&ss->lock, flags);
+
+		m->status = stmp_spi_handle_message(ss, m);
+		if (m->complete)
+			m->complete(m->context);
+
+		spin_lock_irqsave(&ss->lock, flags);
+	}
+	spin_unlock_irqrestore(&ss->lock, flags);
+
+	return;
+}
+
+/**
+ * stmp_spi_transfer - perform message transfer.
+ * Called indirectly from spi_async, queues all the messages to
+ * spi_handle_message.
+ * @spi: spi device
+ * @m: message to be queued
+**/
+static int stmp_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->status = -EINPROGRESS;
+	spin_lock_irqsave(&ss->lock, flags);
+	list_add_tail(&m->queue, &ss->queue);
+	queue_work(ss->workqueue, &ss->work);
+	spin_unlock_irqrestore(&ss->lock, flags);
+	return 0;
+}
+
+static irqreturn_t stmp_spi_irq(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	complete(&ss->done);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+	u32 c1, st;
+
+	c1 = readl(ss->regs + HW_SSP_CTRL1);
+	st = readl(ss->regs + HW_SSP_STATUS);
+	printk(KERN_ERR"IRQ - ERROR!, status = 0x%08X, c1 = 0x%08X\n", st, c1);
+	stmp3xxx_clearl(c1 & 0xCCCC0000, ss->regs + HW_SSP_CTRL1);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit stmp_spi_probe(struct platform_device *dev)
+{
+	int err = 0;
+	struct spi_master *master;
+	struct stmp_spi *ss;
+	struct resource *r;
+
+	/* Get resources(memory, IRQ) associated with the device */
+	master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
+
+	if (master == NULL) {
+		err = -ENOMEM;
+		goto out0;
+	}
+
+	ss = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+	ss->regs = ioremap(r->start, resource_size(r));
+	if (!ss->regs) {
+		err = -EINVAL;
+		goto out_put_master;
+	}
+
+	ss->master_dev = &dev->dev;
+	ss->id = dev->id;
+
+	INIT_WORK(&ss->work, stmp_spi_handle);
+	INIT_LIST_HEAD(&ss->queue);
+	spin_lock_init(&ss->lock);
+
+	ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
+	if (!ss->workqueue) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+	master->transfer = stmp_spi_transfer;
+	master->setup = stmp_spi_setup;
+
+
+	ss->irq = platform_get_irq(dev, 0);
+	if (ss->irq < 0) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+
+	r = platform_get_resource(dev, IORESOURCE_DMA, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+
+	ss->dma = r->start;
+	err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
+	if (err)
+		goto out_put_master;
+
+	err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
+	if (err)
+		goto out_free_dma;
+
+	master->bus_num = dev->id;
+	master->num_chipselect = 1;
+
+	/* SPI controller initializations */
+	err = stmp_spi_init_hw(ss);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot initialize hardware\n");
+		goto out_free_dma_desc;
+	}
+
+	if (clock) {
+		dev_info(&dev->dev, "clock rate forced to %d\n", clock);
+		clk_set_rate(ss->clk, clock);
+	}
+	ss->speed_khz = clk_get_rate(ss->clk);
+	ss->divider = 2;
+	dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
+		ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
+
+	/* Register for SPI interrupt */
+	err = request_irq(ss->irq, stmp_spi_irq, 0,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
+		goto out_release_hw;
+	}
+
+	/* ..and shared interrupt for all SSP controllers */
+	err = request_irq(IRQ_SSP_ERROR, stmp_spi_irq_err, IRQF_SHARED,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
+		goto out_free_irq;
+	}
+
+	err = spi_register_master(master);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot register spi master, %d\n", err);
+		goto out_free_irq_2;
+	}
+	dev_info(&dev->dev, "at (mapped) 0x%08X, irq=%d, bus %d, %s mode\n",
+			(u32)ss->regs, ss->irq, master->bus_num,
+			pio ? "PIO" : "DMA");
+	return 0;
+
+out_free_irq_2:
+	free_irq(IRQ_SSP_ERROR, ss);
+out_free_irq:
+	free_irq(ss->irq, ss);
+out_free_dma_desc:
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+out_free_dma:
+	stmp3xxx_dma_release(ss->dma);
+out_release_hw:
+	stmp_spi_release_hw(ss);
+out_put_master:
+	spi_master_put(master);
+	if (ss->regs)
+		iounmap(ss->regs);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+out0:
+	return err;
+}
+
+static int __devexit stmp_spi_remove(struct platform_device *dev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(dev);
+	if (master == NULL)
+		goto out0;
+	ss = spi_master_get_devdata(master);
+	if (ss == NULL)
+		goto out1;
+	free_irq(ss->irq, ss);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+	if (ss->regs)
+		iounmap(ss->regs);
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+	stmp3xxx_dma_release(ss->dma);
+	stmp_spi_release_hw(ss);
+	platform_set_drvdata(dev, NULL);
+out1:
+	spi_master_put(master);
+out0:
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int stmp_spi_suspend(struct platform_device *pdev, pm_message_t pmsg)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	ss->saved_timings = readl(HW_SSP_TIMING + ss->regs);
+	clk_disable(ss->clk);
+
+	return 0;
+}
+
+static int stmp_spi_resume(struct platform_device *pdev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	clk_enable(ss->clk);
+	stmp3xxx_reset_block(ss->regs, false);
+	writel(ss->saved_timings, ss->regs + HW_SSP_TIMING);
+
+	return 0;
+}
+
+#else
+#define stmp_spi_suspend NULL
+#define stmp_spi_resume  NULL
+#endif
+
+static struct platform_driver stmp_spi_driver = {
+	.probe	= stmp_spi_probe,
+	.remove	= __devexit_p(stmp_spi_remove),
+	.driver = {
+		.name = "stmp37xx_ssp",
+		.owner = THIS_MODULE,
+	},
+	.suspend = stmp_spi_suspend,
+	.resume  = stmp_spi_resume,
+};
+
+static int __init stmp_spi_init(void)
+{
+	return platform_driver_register(&stmp_spi_driver);
+}
+
+static void __exit stmp_spi_exit(void)
+{
+	platform_driver_unregister(&stmp_spi_driver);
+}
+
+module_init(stmp_spi_init);
+module_exit(stmp_spi_exit);
+module_param(pio, int, S_IRUGO);
+module_param(debug, int, 0644);
+module_param(clock, int, S_IRUGO);
+MODULE_AUTHOR("dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>");
+MODULE_DESCRIPTION("STMP3xxx SPI/SSP driver");
+MODULE_LICENSE("GPL");
Index: linux-2.6-arm/drivers/spi/spi_stmp.h
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/spi/spi_stmp.h
@@ -0,0 +1,45 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#ifndef __SPI_STMP_H
+#define __SPI_STMP_H
+
+struct stmp_spi {
+	int		id;
+
+	void *  __iomem regs;	/* vaddr of the control registers */
+
+	u32		irq;
+	u32		dma;
+	struct stmp3xxx_dma_descriptor d;
+
+	u32		speed_khz;
+	u32		saved_timings;
+	u32		divider;
+
+	struct clk	*clk;
+	struct device	*master_dev;
+
+	struct work_struct work;
+	struct workqueue_struct *workqueue;
+	spinlock_t lock;
+	struct list_head queue;
+
+	struct completion done;
+};
+
+#endif /* __SPI_STMP_H */



------------------------------------------------------------------------------
OpenSolaris 2009.06 is a cutting edge operating system for enterprises 
looking to deploy the next generation of Solaris that includes the latest 
innovations from Sun and the OpenSource community. Download a copy and 
enjoy capabilities such as Networking, Storage and Virtualization. 
Go to: http://p.sf.net/sfu/opensolaris-get

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] Freescale STMP spi driver
       [not found] ` <1243971638.4011.16.camel-GL0tbJR47UuzLY3athcO2A@public.gmane.org>
@ 2009-06-03  4:27   ` Baruch Siach
  2009-06-03 16:15     ` [PATCH] Freescale STMP spi driver, revised dmitry pervushin
  0 siblings, 1 reply; 9+ messages in thread
From: Baruch Siach @ 2009-06-03  4:27 UTC (permalink / raw)
  To: dmitry pervushin
  Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f, David Brownell

Hi dmitry,

On Tue, Jun 02, 2009 at 11:40:38PM +0400, dmitry pervushin wrote:
> Hello David,
> 
> Here is the patch for SSP/SPI on STMP3xxx boards; could you please apply
> it? Any comments are appreciated.
> =========================================================================
>
> ...
>
> +/* the spi->mode bits understood by this driver: */
> +#define MODEBITS (SPI_CPOL | SPI_CPHA)
> +static int stmp_spi_setup(struct spi_device *spi)
> +{
> +	struct stmp_spi *ss;
> +
> +	ss = spi_master_get_devdata(spi->master);
> +	if (!spi->bits_per_word)
> +		spi->bits_per_word = 8;
> +	if (spi->mode & ~MODEBITS) {
> +		dev_err(&spi->dev, "%s: unsupported mode bits %x\n",
> +			__func__, spi->mode & ~MODEBITS);
> +		return -EINVAL;
> +	}
> +	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w\n",
> +		__func__, spi->mode & MODEBITS, spi->bits_per_word);
> +	return stmp_spi_setup_transfer(spi, NULL);

This might trash running SPI transfers. The setup() method must not touch 
hardware registers.

> ...
>
> Index: linux-2.6-arm/drivers/spi/spi_stmp.h
> ===================================================================
> --- /dev/null
> +++ linux-2.6-arm/drivers/spi/spi_stmp.h

No need for a separate .h file here, IMO. The stmp_spi struct should go into 
stmp_spi.c.

> @@ -0,0 +1,45 @@
> +/*
> + * Freescale STMP378X SPI master driver
> + *
> + * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> + *
> + * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
> + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
> + */
> +
> +/*
> + * The code contained herein is licensed under the GNU General Public
> + * License. You may obtain a copy of the GNU General Public License
> + * Version 2 or later at the following locations:
> + *
> + * http://www.opensource.org/licenses/gpl-license.html
> + * http://www.gnu.org/copyleft/gpl.html
> + */
> +#ifndef __SPI_STMP_H
> +#define __SPI_STMP_H
> +
> +struct stmp_spi {
> +	int		id;
> +
> +	void *  __iomem regs;	/* vaddr of the control registers */
> +
> +	u32		irq;
> +	u32		dma;
> +	struct stmp3xxx_dma_descriptor d;
> +
> +	u32		speed_khz;
> +	u32		saved_timings;
> +	u32		divider;
> +
> +	struct clk	*clk;
> +	struct device	*master_dev;
> +
> +	struct work_struct work;
> +	struct workqueue_struct *workqueue;
> +	spinlock_t lock;
> +	struct list_head queue;
> +
> +	struct completion done;
> +};
> +
> +#endif /* __SPI_STMP_H */

baruch

-- 
                                                     ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org - tel: +972.2.679.5364, http://www.tkos.co.il -

------------------------------------------------------------------------------
OpenSolaris 2009.06 is a cutting edge operating system for enterprises 
looking to deploy the next generation of Solaris that includes the latest 
innovations from Sun and the OpenSource community. Download a copy and 
enjoy capabilities such as Networking, Storage and Virtualization. 
Go to: http://p.sf.net/sfu/opensolaris-get

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH] Freescale STMP spi driver, revised
  2009-06-03  4:27   ` Baruch Siach
@ 2009-06-03 16:15     ` dmitry pervushin
       [not found]       ` <1244045746.4074.5.camel-GL0tbJR47UuzLY3athcO2A@public.gmane.org>
  0 siblings, 1 reply; 9+ messages in thread
From: dmitry pervushin @ 2009-06-03 16:15 UTC (permalink / raw)
  To: David Brownell; +Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f

Thanks Baruch for reviewing the patch, here is the updated one:

Add the SPI driver for Freescale STMP 3xxx-based boards

Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>

Index: linux-2.6-arm/drivers/spi/Kconfig
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Kconfig
+++ linux-2.6-arm/drivers/spi/Kconfig
@@ -204,6 +204,12 @@ config SPI_SH_SCI
 	help
 	  SPI driver for SuperH SCI blocks.
 
+config SPI_STMP3XXX
+	tristate "Freescale STMP37xx/378x SPI/SSP controller"
+	depends on ARCH_STMP3XXX && SPI_MASTER
+	help
+	  SPI driver for Freescale STMP37xx/378x SoC SSP interface
+
 config SPI_TXX9
 	tristate "Toshiba TXx9 SPI controller"
 	depends on GENERIC_GPIO && CPU_TX49XX
Index: linux-2.6-arm/drivers/spi/Makefile
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Makefile
+++ linux-2.6-arm/drivers/spi/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24x
 obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
+obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
Index: linux-2.6-arm/drivers/spi/spi_stmp.c
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/spi/spi_stmp.c
@@ -0,0 +1,676 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-ssp.h>
+#include <mach/regs-apbh.h>
+
+/* 0 means DMA mode(recommended, default), !0 - PIO mode */
+static int pio;
+static int debug;
+static int clock;
+
+struct stmp_spi {
+	int		id;
+
+	void *  __iomem regs;	/* vaddr of the control registers */
+
+	u32		irq;
+	u32		dma;
+	struct stmp3xxx_dma_descriptor d;
+
+	u32		speed_khz;
+	u32		saved_timings;
+	u32		divider;
+
+	struct clk	*clk;
+	struct device	*master_dev;
+
+	struct work_struct work;
+	struct workqueue_struct *workqueue;
+	spinlock_t lock;
+	struct list_head queue;
+
+	struct completion done;
+};
+
+#define busy_wait(cond)						\
+	({							\
+	  int count;						\
+	  for (count = 1000; (cond) && count > 0; count--)	\
+		  cpu_relax();					\
+	  (count);						\
+	})
+
+/**
+ * stmp_spi_init_hw
+ * Initialize the SSP port
+ */
+static int stmp_spi_init_hw(struct stmp_spi *ss)
+{
+	int err = 0;
+	void *pins = ss->master_dev->platform_data;
+
+	err = stmp3xxx_request_pin_group(pins, dev_name(ss->master_dev));
+	if (err)
+		goto out;
+
+	ss->clk = clk_get(NULL, "ssp");
+	if (IS_ERR(ss->clk)) {
+		err = PTR_ERR(ss->clk);
+		goto out_free_pins;
+	}
+	clk_enable(ss->clk);
+
+	stmp3xxx_reset_block(ss->regs, false);
+	stmp3xxx_dma_reset_channel(ss->dma);
+
+	return 0;
+
+out_free_pins:
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+out:
+	return err;
+}
+
+static void stmp_spi_release_hw(struct stmp_spi *ss)
+{
+	void *pins = ss->master_dev->platform_data;
+
+	if (ss->clk && !IS_ERR(ss->clk)) {
+		clk_disable(ss->clk);
+		clk_put(ss->clk);
+	}
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+}
+
+static int stmp_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	u8 bits_per_word;
+	u32 hz;
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	u16 rate;
+
+	bits_per_word = spi->bits_per_word;
+	if (t && t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+
+	/*
+	  Calculate speed:
+		- by default, use maximum speed from ssp clk
+		- if device overrides it, use it
+		- if transfer specifies other speed, use transfer's one
+	 */
+	hz = 1000 * ss->speed_khz / ss->divider;
+	if (spi->max_speed_hz)
+		hz = min(hz, spi->max_speed_hz);
+	if (t && t->speed_hz)
+		hz = min(hz, t->speed_hz);
+
+	if (hz == 0) {
+		dev_err(&spi->dev, "Cannot continue with zero clock\n");
+		return -EINVAL;
+	}
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
+		hz, ss->speed_khz, ss->divider,
+		ss->speed_khz * 1000 / ss->divider);
+
+	if (ss->speed_khz * 1000 / ss->divider < hz) {
+		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
+			__func__, hz);
+		return -EINVAL;
+	}
+
+	rate = 1000 * ss->speed_khz/ss->divider/hz;
+
+	writel(BF(ss->divider, SSP_TIMING_CLOCK_DIVIDE)		|
+	       BF(rate - 1, SSP_TIMING_CLOCK_RATE),
+	       HW_SSP_TIMING + ss->regs);
+
+	writel(BF(1 /* mode SPI */, SSP_CTRL1_SSP_MODE)		|
+	       BF(4 /* 8 bits   */, SSP_CTRL1_WORD_LENGTH)	|
+	       ((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
+	       ((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
+	       (pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE),
+	       ss->regs + HW_SSP_CTRL1);
+
+	return 0;
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA)
+static int stmp_spi_setup(struct spi_device *spi)
+{
+	struct stmp_spi *ss;
+
+	ss = spi_master_get_devdata(spi->master);
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+	if (spi->mode & ~MODEBITS) {
+		dev_err(&spi->dev, "%s: unsupported mode bits %x\n",
+			__func__, spi->mode & ~MODEBITS);
+		return -EINVAL;
+	}
+	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w\n",
+		__func__, spi->mode & MODEBITS, spi->bits_per_word);
+	return 0;
+}
+
+static inline u32 stmp_spi_cs(unsigned cs)
+{
+	return  ((cs & 1) ? BM_SSP_CTRL0_WAIT_FOR_CMD : 0) |
+		((cs & 2) ? BM_SSP_CTRL0_WAIT_FOR_IRQ : 0);
+}
+
+static int stmp_spi_txrx_dma(struct stmp_spi *ss, int cs,
+		unsigned char *buf, dma_addr_t dma_buf, int len,
+		int *first, int *last, int write)
+{
+	u32 c0 = 0;
+	dma_addr_t spi_buf_dma = dma_buf;
+	int status = 0;
+	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	c0 |= (*first ? BM_SSP_CTRL0_LOCK_CS : 0);
+	c0 |= (*last ? BM_SSP_CTRL0_IGNORE_CRC : 0);
+	c0 |= (write ? 0 : BM_SSP_CTRL0_READ);
+	c0 |= BM_SSP_CTRL0_DATA_XFER;
+
+	c0 |= stmp_spi_cs(cs);
+
+	c0 |= BF(len, SSP_CTRL0_XFER_COUNT);
+
+	if (!dma_buf)
+		spi_buf_dma = dma_map_single(ss->master_dev, buf, len, dir);
+
+	ss->d.command->cmd =
+		BF(len, APBH_CHn_CMD_XFER_COUNT)	|
+		BF(1, APBH_CHn_CMD_CMDWORDS)		|
+		BM_APBH_CHn_CMD_WAIT4ENDCMD		|
+		BM_APBH_CHn_CMD_IRQONCMPLT		|
+		BF(write ? BV_APBH_CHn_CMD_COMMAND__DMA_READ :
+			   BV_APBH_CHn_CMD_COMMAND__DMA_WRITE,
+		   APBH_CHn_CMD_COMMAND);
+	ss->d.command->pio_words[0] = c0;
+	ss->d.command->buf_ptr = spi_buf_dma;
+
+	stmp3xxx_dma_reset_channel(ss->dma);
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	stmp3xxx_dma_enable_interrupt(ss->dma);
+	init_completion(&ss->done);
+	stmp3xxx_dma_go(ss->dma, &ss->d, 1);
+	wait_for_completion(&ss->done);
+
+	if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) & BM_SSP_CTRL0_RUN) == 0)
+		status = ETIMEDOUT;
+
+	if (!dma_buf)
+		dma_unmap_single(ss->master_dev, spi_buf_dma, len, dir);
+
+	return status;
+}
+
+static inline void stmp_spi_enable(struct stmp_spi *ss)
+{
+	stmp3xxx_setl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_clearl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static inline void stmp_spi_disable(struct stmp_spi *ss)
+{
+	stmp3xxx_clearl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_setl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static int stmp_spi_txrx_pio(struct stmp_spi *ss, int cs,
+		unsigned char *buf, int len,
+		int *first, int *last, int write)
+{
+	if (*first) {
+		stmp_spi_enable(ss);
+		*first = 0;
+	}
+
+	stmp3xxx_setl(stmp_spi_cs(cs), ss->regs + HW_SSP_CTRL0);
+
+	while (len--) {
+		if (*last && len == 0) {
+			stmp_spi_disable(ss);
+			*last = 0;
+		}
+
+		stmp3xxx_clearl(BM_SSP_CTRL0_XFER_COUNT,
+				ss->regs + HW_SSP_CTRL0);
+		stmp3xxx_setl(1, ss->regs + HW_SSP_CTRL0);
+
+		if (write)
+			stmp3xxx_clearl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+		else
+			stmp3xxx_setl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+
+		/* Run! */
+		stmp3xxx_setl(BM_SSP_CTRL0_RUN, ss->regs + HW_SSP_CTRL0);
+
+		if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+				BM_SSP_CTRL0_RUN) == 0)
+			break;
+
+		if (write)
+			writel(*buf, ss->regs + HW_SSP_DATA);
+
+		/* Set TRANSFER */
+		stmp3xxx_setl(BM_SSP_CTRL0_DATA_XFER, ss->regs + HW_SSP_CTRL0);
+
+		if (!write) {
+			if (!busy_wait((readl(ss->regs + HW_SSP_STATUS) &
+					BM_SSP_STATUS_FIFO_EMPTY) == 0))
+				break;
+			*buf = readl(ss->regs + HW_SSP_DATA) & 0xFF;
+		}
+
+		if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+					BM_SSP_CTRL0_RUN) == 0)
+			break;
+
+		/* advance to the next byte */
+		buf++;
+	}
+	return len < 0 ? 0 : -ETIMEDOUT;
+}
+
+static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
+{
+	int first, last;
+	struct spi_transfer *t, *tmp_t;
+	int status = 0;
+	int cs;
+
+	first = last = 0;
+
+	cs = m->spi->chip_select;
+
+	list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
+
+		stmp_spi_setup_transfer(m->spi, t);
+
+		if (&t->transfer_list == m->transfers.next)
+			first = !0;
+		if (&t->transfer_list == m->transfers.prev)
+			last = !0;
+		if (t->rx_buf && t->tx_buf) {
+			pr_debug("%s: cannot send and receive simultaneously\n",
+				__func__);
+			return -EINVAL;
+		}
+
+		/*
+		  REVISIT:
+		  here driver completely ignores setting of t->cs_change
+		 */
+		if (t->tx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
+				   t->len, &first, &last, 1) :
+			   stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
+				   t->tx_dma, t->len, &first, &last, 1);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Tx ",
+						DUMP_PREFIX_OFFSET,
+						t->tx_buf, t->len);
+				else
+					pr_debug("Tx: %d bytes\n", t->len);
+			}
+		}
+		if (t->rx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, t->rx_buf,
+				   t->len, &first, &last, 0) :
+			   stmp_spi_txrx_dma(ss, cs, t->rx_buf,
+				   t->rx_dma, t->len, &first, &last, 0);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Rx ",
+						DUMP_PREFIX_OFFSET,
+						t->rx_buf, t->len);
+				else
+					pr_debug("Rx: %d bytes\n", t->len);
+			}
+		}
+
+		if (status)
+			break;
+
+		first = last = 0;
+
+	}
+	return status;
+}
+
+/**
+ * stmp_spi_handle - handle messages from the queue
+ */
+static void stmp_spi_handle(struct work_struct *w)
+{
+	struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
+	unsigned long flags;
+	struct spi_message *m;
+
+	BUG_ON(w == NULL);
+
+	spin_lock_irqsave(&ss->lock, flags);
+	while (!list_empty(&ss->queue)) {
+		m = list_entry(ss->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&ss->lock, flags);
+
+		m->status = stmp_spi_handle_message(ss, m);
+		if (m->complete)
+			m->complete(m->context);
+
+		spin_lock_irqsave(&ss->lock, flags);
+	}
+	spin_unlock_irqrestore(&ss->lock, flags);
+
+	return;
+}
+
+/**
+ * stmp_spi_transfer - perform message transfer.
+ * Called indirectly from spi_async, queues all the messages to
+ * spi_handle_message.
+ * @spi: spi device
+ * @m: message to be queued
+ */
+static int stmp_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->status = -EINPROGRESS;
+	spin_lock_irqsave(&ss->lock, flags);
+	list_add_tail(&m->queue, &ss->queue);
+	queue_work(ss->workqueue, &ss->work);
+	spin_unlock_irqrestore(&ss->lock, flags);
+	return 0;
+}
+
+static irqreturn_t stmp_spi_irq(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	complete(&ss->done);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+	u32 c1, st;
+
+	c1 = readl(ss->regs + HW_SSP_CTRL1);
+	st = readl(ss->regs + HW_SSP_STATUS);
+	printk(KERN_ERR"IRQ - ERROR!, status = 0x%08X, c1 = 0x%08X\n", st, c1);
+	stmp3xxx_clearl(c1 & 0xCCCC0000, ss->regs + HW_SSP_CTRL1);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit stmp_spi_probe(struct platform_device *dev)
+{
+	int err = 0;
+	struct spi_master *master;
+	struct stmp_spi *ss;
+	struct resource *r;
+
+	/* Get resources(memory, IRQ) associated with the device */
+	master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
+
+	if (master == NULL) {
+		err = -ENOMEM;
+		goto out0;
+	}
+
+	ss = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+	ss->regs = ioremap(r->start, resource_size(r));
+	if (!ss->regs) {
+		err = -EINVAL;
+		goto out_put_master;
+	}
+
+	ss->master_dev = &dev->dev;
+	ss->id = dev->id;
+
+	INIT_WORK(&ss->work, stmp_spi_handle);
+	INIT_LIST_HEAD(&ss->queue);
+	spin_lock_init(&ss->lock);
+
+	ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
+	if (!ss->workqueue) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+	master->transfer = stmp_spi_transfer;
+	master->setup = stmp_spi_setup;
+
+
+	ss->irq = platform_get_irq(dev, 0);
+	if (ss->irq < 0) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+
+	r = platform_get_resource(dev, IORESOURCE_DMA, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+
+	ss->dma = r->start;
+	err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
+	if (err)
+		goto out_put_master;
+
+	err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
+	if (err)
+		goto out_free_dma;
+
+	master->bus_num = dev->id;
+	master->num_chipselect = 1;
+
+	/* SPI controller initializations */
+	err = stmp_spi_init_hw(ss);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot initialize hardware\n");
+		goto out_free_dma_desc;
+	}
+
+	if (clock) {
+		dev_info(&dev->dev, "clock rate forced to %d\n", clock);
+		clk_set_rate(ss->clk, clock);
+	}
+	ss->speed_khz = clk_get_rate(ss->clk);
+	ss->divider = 2;
+	dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
+		ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
+
+	/* Register for SPI interrupt */
+	err = request_irq(ss->irq, stmp_spi_irq, 0,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
+		goto out_release_hw;
+	}
+
+	/* ..and shared interrupt for all SSP controllers */
+	err = request_irq(IRQ_SSP_ERROR, stmp_spi_irq_err, IRQF_SHARED,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
+		goto out_free_irq;
+	}
+
+	err = spi_register_master(master);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot register spi master, %d\n", err);
+		goto out_free_irq_2;
+	}
+	dev_info(&dev->dev, "at (mapped) 0x%08X, irq=%d, bus %d, %s mode\n",
+			(u32)ss->regs, ss->irq, master->bus_num,
+			pio ? "PIO" : "DMA");
+	return 0;
+
+out_free_irq_2:
+	free_irq(IRQ_SSP_ERROR, ss);
+out_free_irq:
+	free_irq(ss->irq, ss);
+out_free_dma_desc:
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+out_free_dma:
+	stmp3xxx_dma_release(ss->dma);
+out_release_hw:
+	stmp_spi_release_hw(ss);
+out_put_master:
+	spi_master_put(master);
+	if (ss->regs)
+		iounmap(ss->regs);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+out0:
+	return err;
+}
+
+static int __devexit stmp_spi_remove(struct platform_device *dev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(dev);
+	if (master == NULL)
+		goto out0;
+	ss = spi_master_get_devdata(master);
+	if (ss == NULL)
+		goto out1;
+	free_irq(ss->irq, ss);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+	if (ss->regs)
+		iounmap(ss->regs);
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+	stmp3xxx_dma_release(ss->dma);
+	stmp_spi_release_hw(ss);
+	platform_set_drvdata(dev, NULL);
+out1:
+	spi_master_put(master);
+out0:
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int stmp_spi_suspend(struct platform_device *pdev, pm_message_t pmsg)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	ss->saved_timings = readl(HW_SSP_TIMING + ss->regs);
+	clk_disable(ss->clk);
+
+	return 0;
+}
+
+static int stmp_spi_resume(struct platform_device *pdev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	clk_enable(ss->clk);
+	stmp3xxx_reset_block(ss->regs, false);
+	writel(ss->saved_timings, ss->regs + HW_SSP_TIMING);
+
+	return 0;
+}
+
+#else
+#define stmp_spi_suspend NULL
+#define stmp_spi_resume  NULL
+#endif
+
+static struct platform_driver stmp_spi_driver = {
+	.probe	= stmp_spi_probe,
+	.remove	= __devexit_p(stmp_spi_remove),
+	.driver = {
+		.name = "stmp3xxx_ssp",
+		.owner = THIS_MODULE,
+	},
+	.suspend = stmp_spi_suspend,
+	.resume  = stmp_spi_resume,
+};
+
+static int __init stmp_spi_init(void)
+{
+	return platform_driver_register(&stmp_spi_driver);
+}
+
+static void __exit stmp_spi_exit(void)
+{
+	platform_driver_unregister(&stmp_spi_driver);
+}
+
+module_init(stmp_spi_init);
+module_exit(stmp_spi_exit);
+module_param(pio, int, S_IRUGO);
+module_param(debug, int, 0644);
+module_param(clock, int, S_IRUGO);
+MODULE_AUTHOR("dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>");
+MODULE_DESCRIPTION("STMP3xxx SPI/SSP driver");
+MODULE_LICENSE("GPL");



------------------------------------------------------------------------------
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^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] Freescale STMP spi driver, revised
       [not found]       ` <1244045746.4074.5.camel-GL0tbJR47UuzLY3athcO2A@public.gmane.org>
@ 2009-07-03  4:47         ` David Brownell
       [not found]           ` <200907022147.44892.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
  2009-07-03  7:02         ` [PATCH] Freescale STMP spi driver, revised David Brownell
  1 sibling, 1 reply; 9+ messages in thread
From: David Brownell @ 2009-07-03  4:47 UTC (permalink / raw)
  To: dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf
  Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f, David Brownell

On Wednesday 03 June 2009, dmitry pervushin wrote:
> Add the SPI driver for Freescale STMP 3xxx-based boards
> 
> Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>

Needs the appended fixups for current kernels ...
technical comments in a bit.

- Dave


--- g26.orig/drivers/spi/spi_stmp.c	2009-07-02 21:46:32.000000000 -0700
+++ g26/drivers/spi/spi_stmp.c	2009-07-02 21:22:25.000000000 -0700
@@ -171,22 +171,16 @@ static int stmp_spi_setup_transfer(struc
 	return 0;
 }
 
-/* the spi->mode bits understood by this driver: */
-#define MODEBITS (SPI_CPOL | SPI_CPHA)
 static int stmp_spi_setup(struct spi_device *spi)
 {
-	struct stmp_spi *ss;
-
-	ss = spi_master_get_devdata(spi->master);
-	if (!spi->bits_per_word)
-		spi->bits_per_word = 8;
-	if (spi->mode & ~MODEBITS) {
-		dev_err(&spi->dev, "%s: unsupported mode bits %x\n",
-			__func__, spi->mode & ~MODEBITS);
+	/* spi_setup() does basic checks,
+	 * stmp_spi_setup_transfer() does more later
+	 */
+	if (spi->bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
 		return -EINVAL;
 	}
-	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w\n",
-		__func__, spi->mode & MODEBITS, spi->bits_per_word);
 	return 0;
 }
 
@@ -497,6 +491,8 @@ static int __devinit stmp_spi_probe(stru
 	master->transfer = stmp_spi_transfer;
 	master->setup = stmp_spi_setup;
 
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
 
 	ss->irq = platform_get_irq(dev, 0);
 	if (ss->irq < 0) {


------------------------------------------------------------------------------

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] Freescale STMP spi driver, revised
       [not found]       ` <1244045746.4074.5.camel-GL0tbJR47UuzLY3athcO2A@public.gmane.org>
  2009-07-03  4:47         ` David Brownell
@ 2009-07-03  7:02         ` David Brownell
       [not found]           ` <200907031849.53761.david-b@pacbell.net>
  1 sibling, 1 reply; 9+ messages in thread
From: David Brownell @ 2009-07-03  7:02 UTC (permalink / raw)
  To: dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf
  Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f

On Wednesday 03 June 2009, dmitry pervushin wrote:

> +#define busy_wait(cond)						\
> +	({							\
> +	  int count;						\
> +	  for (count = 1000; (cond) && count > 0; count--)	\

Where does the "1000" come from?

> +		  cpu_relax();					\
> +	  (count);						\
> +	})


> +static int stmp_spi_setup_transfer(struct spi_device *spi,
> +		struct spi_transfer *t)
> +{
> +	u8 bits_per_word;
> +	u32 hz;
> +	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
> +	u16 rate;
> +
> +	bits_per_word = spi->bits_per_word;
> +	if (t && t->bits_per_word)
> +		bits_per_word = t->bits_per_word;
> +
> +	/*
> +	  Calculate speed:
> +		- by default, use maximum speed from ssp clk
> +		- if device overrides it, use it
> +		- if transfer specifies other speed, use transfer's one
> +	 */
> +	hz = 1000 * ss->speed_khz / ss->divider;
> +	if (spi->max_speed_hz)
> +		hz = min(hz, spi->max_speed_hz);
> +	if (t && t->speed_hz)
> +		hz = min(hz, t->speed_hz);
> +
> +	if (hz == 0) {
> +		dev_err(&spi->dev, "Cannot continue with zero clock\n");
> +		return -EINVAL;
> +	}
> +
> +	if (bits_per_word != 8) {
> +		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
> +			__func__, bits_per_word);
> +		return -EINVAL;
> +	}
> +
> +	dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
> +		hz, ss->speed_khz, ss->divider,
> +		ss->speed_khz * 1000 / ss->divider);
> +
> +	if (ss->speed_khz * 1000 / ss->divider < hz) {
> +		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
> +			__func__, hz);
> +		return -EINVAL;
> +	}
> +
> +	rate = 1000 * ss->speed_khz/ss->divider/hz;
> +
> +	writel(BF(ss->divider, SSP_TIMING_CLOCK_DIVIDE)		|
> +	       BF(rate - 1, SSP_TIMING_CLOCK_RATE),
> +	       HW_SSP_TIMING + ss->regs);
> +
> +	writel(BF(1 /* mode SPI */, SSP_CTRL1_SSP_MODE)		|
> +	       BF(4 /* 8 bits   */, SSP_CTRL1_WORD_LENGTH)	|
> +	       ((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
> +	       ((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
> +	       (pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE),
> +	       ss->regs + HW_SSP_CTRL1);

That's kind of long to be doing before each spi_transfer.

You might make your main loop only call that when it knows
the current settings are wrong ... e.g. on the first pass
through the handle_message() loop, and when there are some
per-transfer-overrides to apply/remove.

(That's *only* a performance issue, not a correctness one.)
It will be pretty visible with small transfers.)

> +
> +	return 0;
> +}



> +static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
> +{
> +	int first, last;
> +	struct spi_transfer *t, *tmp_t;
> +	int status = 0;
> +	int cs;
> +
> +	first = last = 0;
> +
> +	cs = m->spi->chip_select;
> +
> +	list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
> +
> +		stmp_spi_setup_transfer(m->spi, t);
> +
> +		if (&t->transfer_list == m->transfers.next)
> +			first = !0;
> +		if (&t->transfer_list == m->transfers.prev)
> +			last = !0;
> +		if (t->rx_buf && t->tx_buf) {
> +			pr_debug("%s: cannot send and receive simultaneously\n",
> +				__func__);

In that case add SPI_MASTER_HALF_DUPLEX to spi_master.flags in
your probe() routine.  Given a patch I sent out earlier today,
you will be able to remove this test from this critical path.


> +			return -EINVAL;
> +		}
> +
> +		/*
> +		  REVISIT:
> +		  here driver completely ignores setting of t->cs_change

Yeah, please fix that.  Minimally, by rejecting submission of
messages where it's set anywhere except in the final transfer.


> +		 */
> +		if (t->tx_buf) {
> +			status = pio ?
> +			   stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
> +				   t->len, &first, &last, 1) :
> +			   stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
> +				   t->tx_dma, t->len, &first, &last, 1);

Rather than "1", or "0" below, please change to "bool" param
and use "true" and "false".  It's still a bit ugly though.


> +			if (debug) {

This debug stuff really ought to be compiled out of the
driver if DEBUG is not set.


> +				if (t->len < 0x10)
> +					print_hex_dump_bytes("Tx ",
> +						DUMP_PREFIX_OFFSET,
> +						t->tx_buf, t->len);
> +				else
> +					pr_debug("Tx: %d bytes\n", t->len);
> +			}
> +		}


> +/**
> + * stmp_spi_handle - handle messages from the queue
> + */
> +static void stmp_spi_handle(struct work_struct *w)
> +{
> +	struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
> +	unsigned long flags;
> +	struct spi_message *m;
> +
> +	BUG_ON(w == NULL);

Strike this BUG_ON(can't happen) ...


> +
> +	spin_lock_irqsave(&ss->lock, flags);
> +	while (!list_empty(&ss->queue)) {
> +		m = list_entry(ss->queue.next, struct spi_message, queue);
> +		list_del_init(&m->queue);
> +		spin_unlock_irqrestore(&ss->lock, flags);
> +
> +		m->status = stmp_spi_handle_message(ss, m);
> +		if (m->complete)

And don't bother checking m->complete either; it's required.


> +			m->complete(m->context);
> +
> +		spin_lock_irqsave(&ss->lock, flags);
> +	}
> +	spin_unlock_irqrestore(&ss->lock, flags);
> +
> +	return;
> +}

> +static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
> +{
> +	struct stmp_spi *ss = dev_id;
> +	u32 c1, st;
> +
> +	c1 = readl(ss->regs + HW_SSP_CTRL1);
> +	st = readl(ss->regs + HW_SSP_STATUS);
> +	printk(KERN_ERR"IRQ - ERROR!, status = 0x%08X, c1 = 0x%08X\n", st, c1);

Make it a dev_err().


> +	stmp3xxx_clearl(c1 & 0xCCCC0000, ss->regs + HW_SSP_CTRL1);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int __devinit stmp_spi_probe(struct platform_device *dev)
> +{
> +	int err = 0;
> +	struct spi_master *master;
> +	struct stmp_spi *ss;
> +	struct resource *r;
> +
> +	/* Get resources(memory, IRQ) associated with the device */

That's not what spi_alloc_master() does ... this comment needs
to be re-located.  :)

> +	master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
> +
> +	if (master == NULL) {
> +		err = -ENOMEM;
> +		goto out0;
> +	}
> +
> +	ss = spi_master_get_devdata(master);
> +	platform_set_drvdata(dev, master);
> +
> +	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
> +	if (r == NULL) {
> +		err = -ENODEV;
> +		goto out_put_master;
> +	}
> +	ss->regs = ioremap(r->start, resource_size(r));
> +	if (!ss->regs) {
> +		err = -EINVAL;
> +		goto out_put_master;
> +	}
> +
> +	ss->master_dev = &dev->dev;
> +	ss->id = dev->id;
> +
> +	INIT_WORK(&ss->work, stmp_spi_handle);
> +	INIT_LIST_HEAD(&ss->queue);
> +	spin_lock_init(&ss->lock);
> +
> +	ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
> +	if (!ss->workqueue) {
> +		err = -ENXIO;
> +		goto out_put_master;
> +	}
> +	master->transfer = stmp_spi_transfer;
> +	master->setup = stmp_spi_setup;
> +
> +
> +	ss->irq = platform_get_irq(dev, 0);
> +	if (ss->irq < 0) {
> +		err = -ENXIO;
> +		goto out_put_master;
> +	}
> +
> +	r = platform_get_resource(dev, IORESOURCE_DMA, 0);
> +	if (r == NULL) {
> +		err = -ENODEV;
> +		goto out_put_master;
> +	}
> +
> +	ss->dma = r->start;
> +	err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
> +	if (err)
> +		goto out_put_master;
> +
> +	err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
> +	if (err)
> +		goto out_free_dma;
> +
> +	master->bus_num = dev->id;
> +	master->num_chipselect = 1;
> +
> +	/* SPI controller initializations */
> +	err = stmp_spi_init_hw(ss);
> +	if (err) {
> +		dev_dbg(&dev->dev, "cannot initialize hardware\n");
> +		goto out_free_dma_desc;
> +	}
> +
> +	if (clock) {
> +		dev_info(&dev->dev, "clock rate forced to %d\n", clock);
> +		clk_set_rate(ss->clk, clock);
> +	}
> +	ss->speed_khz = clk_get_rate(ss->clk);
> +	ss->divider = 2;
> +	dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
> +		ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
> +
> +	/* Register for SPI interrupt */
> +	err = request_irq(ss->irq, stmp_spi_irq, 0,
> +			  dev_name(&dev->dev), ss);
> +	if (err) {
> +		dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
> +		goto out_release_hw;
> +	}
> +
> +	/* ..and shared interrupt for all SSP controllers */
> +	err = request_irq(IRQ_SSP_ERROR, stmp_spi_irq_err, IRQF_SHARED,

This should use a value from the platform resources, not a
constant IRQ_SSP_ERROR (which might change on other silicon).


> +			  dev_name(&dev->dev), ss);
> +	if (err) {
> +		dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
> +		goto out_free_irq;
> +	}


------------------------------------------------------------------------------

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] Freescale STMP spi driver, revised
       [not found]           ` <200907022147.44892.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
@ 2009-07-03 10:23             ` dmitry pervushin
  2009-07-03 10:24             ` [PATCH] Freescale STMP spi driver - take 3 dmitry pervushin
  1 sibling, 0 replies; 9+ messages in thread
From: dmitry pervushin @ 2009-07-03 10:23 UTC (permalink / raw)
  To: David Brownell; +Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f

Thanks for your attention; I tested the change on the board and the
updated patch is in the following message.

On Thu, 2009-07-02 at 21:47 -0700, David Brownell wrote:
> On Wednesday 03 June 2009, dmitry pervushin wrote:
> > Add the SPI driver for Freescale STMP 3xxx-based boards
> > 
> > Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
> 
> Needs the appended fixups for current kernels ...
> technical comments in a bit.
> 
> - Dave
> 
> 
> --- g26.orig/drivers/spi/spi_stmp.c	2009-07-02 21:46:32.000000000 -0700
> +++ g26/drivers/spi/spi_stmp.c	2009-07-02 21:22:25.000000000 -0700
> @@ -171,22 +171,16 @@ static int stmp_spi_setup_transfer(struc
>  	return 0;
>  }
>  
> -/* the spi->mode bits understood by this driver: */
> -#define MODEBITS (SPI_CPOL | SPI_CPHA)
>  static int stmp_spi_setup(struct spi_device *spi)
>  {
> -	struct stmp_spi *ss;
> -
> -	ss = spi_master_get_devdata(spi->master);
> -	if (!spi->bits_per_word)
> -		spi->bits_per_word = 8;
> -	if (spi->mode & ~MODEBITS) {
> -		dev_err(&spi->dev, "%s: unsupported mode bits %x\n",
> -			__func__, spi->mode & ~MODEBITS);
> +	/* spi_setup() does basic checks,
> +	 * stmp_spi_setup_transfer() does more later
> +	 */
> +	if (spi->bits_per_word != 8) {
> +		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
> +			__func__, bits_per_word);
>  		return -EINVAL;
>  	}
> -	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w\n",
> -		__func__, spi->mode & MODEBITS, spi->bits_per_word);
>  	return 0;
>  }
>  
> @@ -497,6 +491,8 @@ static int __devinit stmp_spi_probe(stru
>  	master->transfer = stmp_spi_transfer;
>  	master->setup = stmp_spi_setup;
>  
> +	/* the spi->mode bits understood by this driver: */
> +	master->mode_bits = SPI_CPOL | SPI_CPHA;
>  
>  	ss->irq = platform_get_irq(dev, 0);
>  	if (ss->irq < 0) {
> 


------------------------------------------------------------------------------

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] Freescale STMP spi driver - take 3
       [not found]           ` <200907022147.44892.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
  2009-07-03 10:23             ` dmitry pervushin
@ 2009-07-03 10:24             ` dmitry pervushin
  1 sibling, 0 replies; 9+ messages in thread
From: dmitry pervushin @ 2009-07-03 10:24 UTC (permalink / raw)
  To: David Brownell; +Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f

Add the SPI driver for Freescale STMP 3xxx-based boards
 
Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
---
 drivers/spi/Kconfig    |    6 
 drivers/spi/Makefile   |    1 
 drivers/spi/spi_stmp.c |  672 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 679 insertions(+)

Index: linux-2.6-arm/drivers/spi/Kconfig
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Kconfig
+++ linux-2.6-arm/drivers/spi/Kconfig
@@ -213,6 +213,12 @@ config SPI_SH_SCI
 	help
 	  SPI driver for SuperH SCI blocks.
 
+config SPI_STMP3XXX
+	tristate "Freescale STMP37xx/378x SPI/SSP controller"
+	depends on ARCH_STMP3XXX && SPI_MASTER
+	help
+	  SPI driver for Freescale STMP37xx/378x SoC SSP interface
+
 config SPI_TXX9
 	tristate "Toshiba TXx9 SPI controller"
 	depends on GENERIC_GPIO && CPU_TX49XX
Index: linux-2.6-arm/drivers/spi/Makefile
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Makefile
+++ linux-2.6-arm/drivers/spi/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24x
 obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
+obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
Index: linux-2.6-arm/drivers/spi/spi_stmp.c
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/spi/spi_stmp.c
@@ -0,0 +1,672 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-ssp.h>
+#include <mach/regs-apbh.h>
+
+/* 0 means DMA mode(recommended, default), !0 - PIO mode */
+static int pio;
+static int debug;
+static int clock;
+
+struct stmp_spi {
+	int		id;
+
+	void *  __iomem regs;	/* vaddr of the control registers */
+
+	u32		irq;
+	u32		dma;
+	struct stmp3xxx_dma_descriptor d;
+
+	u32		speed_khz;
+	u32		saved_timings;
+	u32		divider;
+
+	struct clk	*clk;
+	struct device	*master_dev;
+
+	struct work_struct work;
+	struct workqueue_struct *workqueue;
+	spinlock_t lock;
+	struct list_head queue;
+
+	struct completion done;
+};
+
+#define busy_wait(cond)						\
+	({							\
+	  int count;						\
+	  for (count = 1000; (cond) && count > 0; count--)	\
+		  cpu_relax();					\
+	  (count);						\
+	})
+
+/**
+ * stmp_spi_init_hw
+ * Initialize the SSP port
+ */
+static int stmp_spi_init_hw(struct stmp_spi *ss)
+{
+	int err = 0;
+	void *pins = ss->master_dev->platform_data;
+
+	err = stmp3xxx_request_pin_group(pins, dev_name(ss->master_dev));
+	if (err)
+		goto out;
+
+	ss->clk = clk_get(NULL, "ssp");
+	if (IS_ERR(ss->clk)) {
+		err = PTR_ERR(ss->clk);
+		goto out_free_pins;
+	}
+	clk_enable(ss->clk);
+
+	stmp3xxx_reset_block(ss->regs, false);
+	stmp3xxx_dma_reset_channel(ss->dma);
+
+	return 0;
+
+out_free_pins:
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+out:
+	return err;
+}
+
+static void stmp_spi_release_hw(struct stmp_spi *ss)
+{
+	void *pins = ss->master_dev->platform_data;
+
+	if (ss->clk && !IS_ERR(ss->clk)) {
+		clk_disable(ss->clk);
+		clk_put(ss->clk);
+	}
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+}
+
+static int stmp_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	u8 bits_per_word;
+	u32 hz;
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	u16 rate;
+
+	bits_per_word = spi->bits_per_word;
+	if (t && t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+
+	/*
+	  Calculate speed:
+		- by default, use maximum speed from ssp clk
+		- if device overrides it, use it
+		- if transfer specifies other speed, use transfer's one
+	 */
+	hz = 1000 * ss->speed_khz / ss->divider;
+	if (spi->max_speed_hz)
+		hz = min(hz, spi->max_speed_hz);
+	if (t && t->speed_hz)
+		hz = min(hz, t->speed_hz);
+
+	if (hz == 0) {
+		dev_err(&spi->dev, "Cannot continue with zero clock\n");
+		return -EINVAL;
+	}
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
+		hz, ss->speed_khz, ss->divider,
+		ss->speed_khz * 1000 / ss->divider);
+
+	if (ss->speed_khz * 1000 / ss->divider < hz) {
+		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
+			__func__, hz);
+		return -EINVAL;
+	}
+
+	rate = 1000 * ss->speed_khz/ss->divider/hz;
+
+	writel(BF(ss->divider, SSP_TIMING_CLOCK_DIVIDE)		|
+	       BF(rate - 1, SSP_TIMING_CLOCK_RATE),
+	       HW_SSP_TIMING + ss->regs);
+
+	writel(BF(1 /* mode SPI */, SSP_CTRL1_SSP_MODE)		|
+	       BF(4 /* 8 bits   */, SSP_CTRL1_WORD_LENGTH)	|
+	       ((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
+	       ((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
+	       (pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE),
+	       ss->regs + HW_SSP_CTRL1);
+
+	return 0;
+}
+
+static int stmp_spi_setup(struct spi_device *spi)
+{
+	/* spi_setup() does basic checks,
+	 * stmp_spi_setup_transfer() does more later
+	 */
+	if (spi->bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static inline u32 stmp_spi_cs(unsigned cs)
+{
+	return  ((cs & 1) ? BM_SSP_CTRL0_WAIT_FOR_CMD : 0) |
+		((cs & 2) ? BM_SSP_CTRL0_WAIT_FOR_IRQ : 0);
+}
+
+static int stmp_spi_txrx_dma(struct stmp_spi *ss, int cs,
+		unsigned char *buf, dma_addr_t dma_buf, int len,
+		int *first, int *last, int write)
+{
+	u32 c0 = 0;
+	dma_addr_t spi_buf_dma = dma_buf;
+	int status = 0;
+	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	c0 |= (*first ? BM_SSP_CTRL0_LOCK_CS : 0);
+	c0 |= (*last ? BM_SSP_CTRL0_IGNORE_CRC : 0);
+	c0 |= (write ? 0 : BM_SSP_CTRL0_READ);
+	c0 |= BM_SSP_CTRL0_DATA_XFER;
+
+	c0 |= stmp_spi_cs(cs);
+
+	c0 |= BF(len, SSP_CTRL0_XFER_COUNT);
+
+	if (!dma_buf)
+		spi_buf_dma = dma_map_single(ss->master_dev, buf, len, dir);
+
+	ss->d.command->cmd =
+		BF(len, APBH_CHn_CMD_XFER_COUNT)	|
+		BF(1, APBH_CHn_CMD_CMDWORDS)		|
+		BM_APBH_CHn_CMD_WAIT4ENDCMD		|
+		BM_APBH_CHn_CMD_IRQONCMPLT		|
+		BF(write ? BV_APBH_CHn_CMD_COMMAND__DMA_READ :
+			   BV_APBH_CHn_CMD_COMMAND__DMA_WRITE,
+		   APBH_CHn_CMD_COMMAND);
+	ss->d.command->pio_words[0] = c0;
+	ss->d.command->buf_ptr = spi_buf_dma;
+
+	stmp3xxx_dma_reset_channel(ss->dma);
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	stmp3xxx_dma_enable_interrupt(ss->dma);
+	init_completion(&ss->done);
+	stmp3xxx_dma_go(ss->dma, &ss->d, 1);
+	wait_for_completion(&ss->done);
+
+	if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) & BM_SSP_CTRL0_RUN) == 0)
+		status = ETIMEDOUT;
+
+	if (!dma_buf)
+		dma_unmap_single(ss->master_dev, spi_buf_dma, len, dir);
+
+	return status;
+}
+
+static inline void stmp_spi_enable(struct stmp_spi *ss)
+{
+	stmp3xxx_setl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_clearl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static inline void stmp_spi_disable(struct stmp_spi *ss)
+{
+	stmp3xxx_clearl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_setl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static int stmp_spi_txrx_pio(struct stmp_spi *ss, int cs,
+		unsigned char *buf, int len,
+		int *first, int *last, int write)
+{
+	if (*first) {
+		stmp_spi_enable(ss);
+		*first = 0;
+	}
+
+	stmp3xxx_setl(stmp_spi_cs(cs), ss->regs + HW_SSP_CTRL0);
+
+	while (len--) {
+		if (*last && len == 0) {
+			stmp_spi_disable(ss);
+			*last = 0;
+		}
+
+		stmp3xxx_clearl(BM_SSP_CTRL0_XFER_COUNT,
+				ss->regs + HW_SSP_CTRL0);
+		stmp3xxx_setl(1, ss->regs + HW_SSP_CTRL0);
+
+		if (write)
+			stmp3xxx_clearl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+		else
+			stmp3xxx_setl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+
+		/* Run! */
+		stmp3xxx_setl(BM_SSP_CTRL0_RUN, ss->regs + HW_SSP_CTRL0);
+
+		if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+				BM_SSP_CTRL0_RUN) == 0)
+			break;
+
+		if (write)
+			writel(*buf, ss->regs + HW_SSP_DATA);
+
+		/* Set TRANSFER */
+		stmp3xxx_setl(BM_SSP_CTRL0_DATA_XFER, ss->regs + HW_SSP_CTRL0);
+
+		if (!write) {
+			if (!busy_wait((readl(ss->regs + HW_SSP_STATUS) &
+					BM_SSP_STATUS_FIFO_EMPTY) == 0))
+				break;
+			*buf = readl(ss->regs + HW_SSP_DATA) & 0xFF;
+		}
+
+		if (busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+					BM_SSP_CTRL0_RUN) == 0)
+			break;
+
+		/* advance to the next byte */
+		buf++;
+	}
+	return len < 0 ? 0 : -ETIMEDOUT;
+}
+
+static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
+{
+	int first, last;
+	struct spi_transfer *t, *tmp_t;
+	int status = 0;
+	int cs;
+
+	first = last = 0;
+
+	cs = m->spi->chip_select;
+
+	list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
+
+		stmp_spi_setup_transfer(m->spi, t);
+
+		if (&t->transfer_list == m->transfers.next)
+			first = !0;
+		if (&t->transfer_list == m->transfers.prev)
+			last = !0;
+		if (t->rx_buf && t->tx_buf) {
+			pr_debug("%s: cannot send and receive simultaneously\n",
+				__func__);
+			return -EINVAL;
+		}
+
+		/*
+		  REVISIT:
+		  here driver completely ignores setting of t->cs_change
+		 */
+		if (t->tx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
+				   t->len, &first, &last, 1) :
+			   stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
+				   t->tx_dma, t->len, &first, &last, 1);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Tx ",
+						DUMP_PREFIX_OFFSET,
+						t->tx_buf, t->len);
+				else
+					pr_debug("Tx: %d bytes\n", t->len);
+			}
+		}
+		if (t->rx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, t->rx_buf,
+				   t->len, &first, &last, 0) :
+			   stmp_spi_txrx_dma(ss, cs, t->rx_buf,
+				   t->rx_dma, t->len, &first, &last, 0);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Rx ",
+						DUMP_PREFIX_OFFSET,
+						t->rx_buf, t->len);
+				else
+					pr_debug("Rx: %d bytes\n", t->len);
+			}
+		}
+
+		if (status)
+			break;
+
+		first = last = 0;
+
+	}
+	return status;
+}
+
+/**
+ * stmp_spi_handle - handle messages from the queue
+ */
+static void stmp_spi_handle(struct work_struct *w)
+{
+	struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
+	unsigned long flags;
+	struct spi_message *m;
+
+	BUG_ON(w == NULL);
+
+	spin_lock_irqsave(&ss->lock, flags);
+	while (!list_empty(&ss->queue)) {
+		m = list_entry(ss->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&ss->lock, flags);
+
+		m->status = stmp_spi_handle_message(ss, m);
+		if (m->complete)
+			m->complete(m->context);
+
+		spin_lock_irqsave(&ss->lock, flags);
+	}
+	spin_unlock_irqrestore(&ss->lock, flags);
+
+	return;
+}
+
+/**
+ * stmp_spi_transfer - perform message transfer.
+ * Called indirectly from spi_async, queues all the messages to
+ * spi_handle_message.
+ * @spi: spi device
+ * @m: message to be queued
+ */
+static int stmp_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->status = -EINPROGRESS;
+	spin_lock_irqsave(&ss->lock, flags);
+	list_add_tail(&m->queue, &ss->queue);
+	queue_work(ss->workqueue, &ss->work);
+	spin_unlock_irqrestore(&ss->lock, flags);
+	return 0;
+}
+
+static irqreturn_t stmp_spi_irq(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	complete(&ss->done);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+	u32 c1, st;
+
+	c1 = readl(ss->regs + HW_SSP_CTRL1);
+	st = readl(ss->regs + HW_SSP_STATUS);
+	printk(KERN_ERR"IRQ - ERROR!, status = 0x%08X, c1 = 0x%08X\n", st, c1);
+	stmp3xxx_clearl(c1 & 0xCCCC0000, ss->regs + HW_SSP_CTRL1);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit stmp_spi_probe(struct platform_device *dev)
+{
+	int err = 0;
+	struct spi_master *master;
+	struct stmp_spi *ss;
+	struct resource *r;
+
+	/* Get resources(memory, IRQ) associated with the device */
+	master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
+
+	if (master == NULL) {
+		err = -ENOMEM;
+		goto out0;
+	}
+
+	ss = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+	ss->regs = ioremap(r->start, resource_size(r));
+	if (!ss->regs) {
+		err = -EINVAL;
+		goto out_put_master;
+	}
+
+	ss->master_dev = &dev->dev;
+	ss->id = dev->id;
+
+	INIT_WORK(&ss->work, stmp_spi_handle);
+	INIT_LIST_HEAD(&ss->queue);
+	spin_lock_init(&ss->lock);
+
+	ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
+	if (!ss->workqueue) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+	master->transfer = stmp_spi_transfer;
+	master->setup = stmp_spi_setup;
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+
+	ss->irq = platform_get_irq(dev, 0);
+	if (ss->irq < 0) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+
+	r = platform_get_resource(dev, IORESOURCE_DMA, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+
+	ss->dma = r->start;
+	err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
+	if (err)
+		goto out_put_master;
+
+	err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
+	if (err)
+		goto out_free_dma;
+
+	master->bus_num = dev->id;
+	master->num_chipselect = 1;
+
+	/* SPI controller initializations */
+	err = stmp_spi_init_hw(ss);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot initialize hardware\n");
+		goto out_free_dma_desc;
+	}
+
+	if (clock) {
+		dev_info(&dev->dev, "clock rate forced to %d\n", clock);
+		clk_set_rate(ss->clk, clock);
+	}
+	ss->speed_khz = clk_get_rate(ss->clk);
+	ss->divider = 2;
+	dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
+		ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
+
+	/* Register for SPI interrupt */
+	err = request_irq(ss->irq, stmp_spi_irq, 0,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
+		goto out_release_hw;
+	}
+
+	/* ..and shared interrupt for all SSP controllers */
+	err = request_irq(IRQ_SSP_ERROR, stmp_spi_irq_err, IRQF_SHARED,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
+		goto out_free_irq;
+	}
+
+	err = spi_register_master(master);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot register spi master, %d\n", err);
+		goto out_free_irq_2;
+	}
+	dev_info(&dev->dev, "at (mapped) 0x%08X, irq=%d, bus %d, %s mode\n",
+			(u32)ss->regs, ss->irq, master->bus_num,
+			pio ? "PIO" : "DMA");
+	return 0;
+
+out_free_irq_2:
+	free_irq(IRQ_SSP_ERROR, ss);
+out_free_irq:
+	free_irq(ss->irq, ss);
+out_free_dma_desc:
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+out_free_dma:
+	stmp3xxx_dma_release(ss->dma);
+out_release_hw:
+	stmp_spi_release_hw(ss);
+out_put_master:
+	spi_master_put(master);
+	if (ss->regs)
+		iounmap(ss->regs);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+out0:
+	return err;
+}
+
+static int __devexit stmp_spi_remove(struct platform_device *dev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(dev);
+	if (master == NULL)
+		goto out0;
+	ss = spi_master_get_devdata(master);
+	if (ss == NULL)
+		goto out1;
+	free_irq(ss->irq, ss);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+	if (ss->regs)
+		iounmap(ss->regs);
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+	stmp3xxx_dma_release(ss->dma);
+	stmp_spi_release_hw(ss);
+	platform_set_drvdata(dev, NULL);
+out1:
+	spi_master_put(master);
+out0:
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int stmp_spi_suspend(struct platform_device *pdev, pm_message_t pmsg)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	ss->saved_timings = readl(HW_SSP_TIMING + ss->regs);
+	clk_disable(ss->clk);
+
+	return 0;
+}
+
+static int stmp_spi_resume(struct platform_device *pdev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	clk_enable(ss->clk);
+	stmp3xxx_reset_block(ss->regs, false);
+	writel(ss->saved_timings, ss->regs + HW_SSP_TIMING);
+
+	return 0;
+}
+
+#else
+#define stmp_spi_suspend NULL
+#define stmp_spi_resume  NULL
+#endif
+
+static struct platform_driver stmp_spi_driver = {
+	.probe	= stmp_spi_probe,
+	.remove	= __devexit_p(stmp_spi_remove),
+	.driver = {
+		.name = "stmp3xxx_ssp",
+		.owner = THIS_MODULE,
+	},
+	.suspend = stmp_spi_suspend,
+	.resume  = stmp_spi_resume,
+};
+
+static int __init stmp_spi_init(void)
+{
+	return platform_driver_register(&stmp_spi_driver);
+}
+
+static void __exit stmp_spi_exit(void)
+{
+	platform_driver_unregister(&stmp_spi_driver);
+}
+
+module_init(stmp_spi_init);
+module_exit(stmp_spi_exit);
+module_param(pio, int, S_IRUGO);
+module_param(debug, int, 0644);
+module_param(clock, int, S_IRUGO);
+MODULE_AUTHOR("dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>");
+MODULE_DESCRIPTION("STMP3xxx SPI/SSP driver");
+MODULE_LICENSE("GPL");



------------------------------------------------------------------------------

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] Freescale STMP spi driver, revised
       [not found]             ` <200907031849.53761.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
@ 2009-07-07 14:14               ` dmitry pervushin
  0 siblings, 0 replies; 9+ messages in thread
From: dmitry pervushin @ 2009-07-07 14:14 UTC (permalink / raw)
  To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f

Crossposted to mailing list

On Fri, 2009-07-03 at 18:49 -0700, David Brownell wrote:
> Your updated patch only addressed the minor fixup I sent,
> not the technical feedback I sent (included below) ...
> I'll wait for an update on those points too.
Thanks for your review; the updated patch is inlined below.

Add the SPI driver for Freescale STMP 3xxx-based boards
                                                                      > 
Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
---
 drivers/spi/Kconfig    |    6 
 drivers/spi/Makefile   |    1 
 drivers/spi/spi_stmp.c |  677 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 684 insertions(+)

Index: linux-2.6/drivers/spi/Kconfig
===================================================================
--- linux-2.6.orig/drivers/spi/Kconfig
+++ linux-2.6/drivers/spi/Kconfig
@@ -211,6 +211,12 @@ config SPI_SH_SCI
 	help
 	  SPI driver for SuperH SCI blocks.
 
+config SPI_STMP3XXX
+	tristate "Freescale STMP37xx/378x SPI/SSP controller"
+	depends on ARCH_STMP3XXX && SPI_MASTER
+	help
+	  SPI driver for Freescale STMP37xx/378x SoC SSP interface
+
 config SPI_TXX9
 	tristate "Toshiba TXx9 SPI controller"
 	depends on GENERIC_GPIO && CPU_TX49XX
Index: linux-2.6/drivers/spi/Makefile
===================================================================
--- linux-2.6.orig/drivers/spi/Makefile
+++ linux-2.6/drivers/spi/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24x
 obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
+obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
Index: linux-2.6/drivers/spi/spi_stmp.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/spi/spi_stmp.c
@@ -0,0 +1,677 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+
+#include <mach/platform.h>
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-ssp.h>
+#include <mach/regs-apbh.h>
+
+/* 0 means DMA mode(recommended, default), !0 - PIO mode */
+static int pio;
+static int clock;
+
+/* default timeout for busy waits is 2 seconds */
+#define STMP_SPI_TIMEOUT	(2 * HZ)
+
+struct stmp_spi {
+	int		id;
+
+	void *  __iomem regs;	/* vaddr of the control registers */
+
+	int		irq, err_irq;
+	u32		dma;
+	struct stmp3xxx_dma_descriptor d;
+
+	u32		speed_khz;
+	u32		saved_timings;
+	u32		divider;
+
+	struct clk	*clk;
+	struct device	*master_dev;
+
+	struct work_struct work;
+	struct workqueue_struct *workqueue;
+	spinlock_t lock;
+	struct list_head queue;
+
+	struct completion done;
+};
+
+#define busy_wait(cond)							\
+	({								\
+	unsigned long end_jiffies = jiffies + STMP_SPI_TIMEOUT;		\
+	bool succeeded = false;						\
+	do {								\
+		if (cond) {						\
+			succeeded = true;				\
+			break;						\
+		}							\
+		cpu_relax();						\
+	} while (time_before(end_jiffies, jiffies));			\
+	succeeded;							\
+	})
+
+/**
+ * stmp_spi_init_hw
+ * Initialize the SSP port
+ */
+static int stmp_spi_init_hw(struct stmp_spi *ss)
+{
+	int err = 0;
+	void *pins = ss->master_dev->platform_data;
+
+	err = stmp3xxx_request_pin_group(pins, dev_name(ss->master_dev));
+	if (err)
+		goto out;
+
+	ss->clk = clk_get(NULL, "ssp");
+	if (IS_ERR(ss->clk)) {
+		err = PTR_ERR(ss->clk);
+		goto out_free_pins;
+	}
+	clk_enable(ss->clk);
+
+	stmp3xxx_reset_block(ss->regs, false);
+	stmp3xxx_dma_reset_channel(ss->dma);
+
+	return 0;
+
+out_free_pins:
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+out:
+	return err;
+}
+
+static void stmp_spi_release_hw(struct stmp_spi *ss)
+{
+	void *pins = ss->master_dev->platform_data;
+
+	if (ss->clk && !IS_ERR(ss->clk)) {
+		clk_disable(ss->clk);
+		clk_put(ss->clk);
+	}
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+}
+
+static int stmp_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	u8 bits_per_word;
+	u32 hz;
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	u16 rate;
+
+	bits_per_word = spi->bits_per_word;
+	if (t && t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+
+	/*
+	  Calculate speed:
+		- by default, use maximum speed from ssp clk
+		- if device overrides it, use it
+		- if transfer specifies other speed, use transfer's one
+	 */
+	hz = 1000 * ss->speed_khz / ss->divider;
+	if (spi->max_speed_hz)
+		hz = min(hz, spi->max_speed_hz);
+	if (t && t->speed_hz)
+		hz = min(hz, t->speed_hz);
+
+	if (hz == 0) {
+		dev_err(&spi->dev, "Cannot continue with zero clock\n");
+		return -EINVAL;
+	}
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
+		hz, ss->speed_khz, ss->divider,
+		ss->speed_khz * 1000 / ss->divider);
+
+	if (ss->speed_khz * 1000 / ss->divider < hz) {
+		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
+			__func__, hz);
+		return -EINVAL;
+	}
+
+	rate = 1000 * ss->speed_khz/ss->divider/hz;
+
+	writel(BF(ss->divider, SSP_TIMING_CLOCK_DIVIDE)		|
+	       BF(rate - 1, SSP_TIMING_CLOCK_RATE),
+	       HW_SSP_TIMING + ss->regs);
+
+	writel(BF(1 /* mode SPI */, SSP_CTRL1_SSP_MODE)		|
+	       BF(4 /* 8 bits   */, SSP_CTRL1_WORD_LENGTH)	|
+	       ((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
+	       ((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
+	       (pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE),
+	       ss->regs + HW_SSP_CTRL1);
+
+	return 0;
+}
+
+static int stmp_spi_setup(struct spi_device *spi)
+{
+	/* spi_setup() does basic checks,
+	 * stmp_spi_setup_transfer() does more later
+	 */
+	if (spi->bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, spi->bits_per_word);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static inline u32 stmp_spi_cs(unsigned cs)
+{
+	return  ((cs & 1) ? BM_SSP_CTRL0_WAIT_FOR_CMD : 0) |
+		((cs & 2) ? BM_SSP_CTRL0_WAIT_FOR_IRQ : 0);
+}
+
+static int stmp_spi_txrx_dma(struct stmp_spi *ss, int cs,
+		unsigned char *buf, dma_addr_t dma_buf, int len,
+		int first, int last, bool write)
+{
+	u32 c0 = 0;
+	dma_addr_t spi_buf_dma = dma_buf;
+	int status = 0;
+	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	c0 |= (first ? BM_SSP_CTRL0_LOCK_CS : 0);
+	c0 |= (last ? BM_SSP_CTRL0_IGNORE_CRC : 0);
+	c0 |= (write ? 0 : BM_SSP_CTRL0_READ);
+	c0 |= BM_SSP_CTRL0_DATA_XFER;
+
+	c0 |= stmp_spi_cs(cs);
+
+	c0 |= BF(len, SSP_CTRL0_XFER_COUNT);
+
+	if (!dma_buf)
+		spi_buf_dma = dma_map_single(ss->master_dev, buf, len, dir);
+
+	ss->d.command->cmd =
+		BF(len, APBH_CHn_CMD_XFER_COUNT)	|
+		BF(1, APBH_CHn_CMD_CMDWORDS)		|
+		BM_APBH_CHn_CMD_WAIT4ENDCMD		|
+		BM_APBH_CHn_CMD_IRQONCMPLT		|
+		BF(write ? BV_APBH_CHn_CMD_COMMAND__DMA_READ :
+			   BV_APBH_CHn_CMD_COMMAND__DMA_WRITE,
+		   APBH_CHn_CMD_COMMAND);
+	ss->d.command->pio_words[0] = c0;
+	ss->d.command->buf_ptr = spi_buf_dma;
+
+	stmp3xxx_dma_reset_channel(ss->dma);
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	stmp3xxx_dma_enable_interrupt(ss->dma);
+	init_completion(&ss->done);
+	stmp3xxx_dma_go(ss->dma, &ss->d, 1);
+	wait_for_completion(&ss->done);
+
+	if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) & BM_SSP_CTRL0_RUN))
+		status = ETIMEDOUT;
+
+	if (!dma_buf)
+		dma_unmap_single(ss->master_dev, spi_buf_dma, len, dir);
+
+	return status;
+}
+
+static inline void stmp_spi_enable(struct stmp_spi *ss)
+{
+	stmp3xxx_setl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_clearl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static inline void stmp_spi_disable(struct stmp_spi *ss)
+{
+	stmp3xxx_clearl(BM_SSP_CTRL0_LOCK_CS, ss->regs + HW_SSP_CTRL0);
+	stmp3xxx_setl(BM_SSP_CTRL0_IGNORE_CRC, ss->regs + HW_SSP_CTRL0);
+}
+
+static int stmp_spi_txrx_pio(struct stmp_spi *ss, int cs,
+		unsigned char *buf, int len,
+		bool first, bool last, bool write)
+{
+	if (first)
+		stmp_spi_enable(ss);
+
+	stmp3xxx_setl(stmp_spi_cs(cs), ss->regs + HW_SSP_CTRL0);
+
+	while (len--) {
+		if (last && len <= 0)
+			stmp_spi_disable(ss);
+
+		stmp3xxx_clearl(BM_SSP_CTRL0_XFER_COUNT,
+				ss->regs + HW_SSP_CTRL0);
+		stmp3xxx_setl(1, ss->regs + HW_SSP_CTRL0);
+
+		if (write)
+			stmp3xxx_clearl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+		else
+			stmp3xxx_setl(BM_SSP_CTRL0_READ,
+					ss->regs + HW_SSP_CTRL0);
+
+		/* Run! */
+		stmp3xxx_setl(BM_SSP_CTRL0_RUN, ss->regs + HW_SSP_CTRL0);
+
+		if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+				BM_SSP_CTRL0_RUN))
+			break;
+
+		if (write)
+			writel(*buf, ss->regs + HW_SSP_DATA);
+
+		/* Set TRANSFER */
+		stmp3xxx_setl(BM_SSP_CTRL0_DATA_XFER, ss->regs + HW_SSP_CTRL0);
+
+		if (!write) {
+			if (busy_wait((readl(ss->regs + HW_SSP_STATUS) &
+					BM_SSP_STATUS_FIFO_EMPTY)))
+				break;
+			*buf = readl(ss->regs + HW_SSP_DATA) & 0xFF;
+		}
+
+		if (!busy_wait(readl(ss->regs + HW_SSP_CTRL0) &
+					BM_SSP_CTRL0_RUN))
+			break;
+
+		/* advance to the next byte */
+		buf++;
+	}
+
+	return len < 0 ? 0 : -ETIMEDOUT;
+}
+
+static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
+{
+	bool first, last;
+	struct spi_transfer *t, *tmp_t;
+	int status = 0;
+	int cs;
+
+	cs = m->spi->chip_select;
+
+	list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
+
+		first = (&t->transfer_list == m->transfers.next);
+		last = (&t->transfer_list == m->transfers.prev);
+
+		if (first || t->speed_hz || t->bits_per_word)
+			stmp_spi_setup_transfer(m->spi, t);
+
+		/* reject "not last" transfers which request to change cs */
+		if (t->cs_change && !last) {
+			dev_err(&m->spi->dev,
+				"Message with t->cs_change has been skipped\n");
+			continue;
+		}
+
+		if (t->tx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
+				   t->len, first, last, true) :
+			   stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
+				   t->tx_dma, t->len, first, last, true);
+#ifdef DEBUG
+			if (t->len < 0x10)
+				print_hex_dump_bytes("Tx ",
+					DUMP_PREFIX_OFFSET,
+					t->tx_buf, t->len);
+			else
+				pr_debug("Tx: %d bytes\n", t->len);
+#endif
+		}
+		if (t->rx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, t->rx_buf,
+				   t->len, first, last, false) :
+			   stmp_spi_txrx_dma(ss, cs, t->rx_buf,
+				   t->rx_dma, t->len, first, last, false);
+#ifdef DEBUG
+			if (t->len < 0x10)
+				print_hex_dump_bytes("Rx ",
+					DUMP_PREFIX_OFFSET,
+					t->rx_buf, t->len);
+			else
+				pr_debug("Rx: %d bytes\n", t->len);
+#endif
+		}
+
+		if (t->delay_usecs)
+			udelay(t->delay_usecs);
+
+		if (status)
+			break;
+
+	}
+	return status;
+}
+
+/**
+ * stmp_spi_handle - handle messages from the queue
+ */
+static void stmp_spi_handle(struct work_struct *w)
+{
+	struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
+	unsigned long flags;
+	struct spi_message *m;
+
+	spin_lock_irqsave(&ss->lock, flags);
+	while (!list_empty(&ss->queue)) {
+		m = list_entry(ss->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&ss->lock, flags);
+
+		m->status = stmp_spi_handle_message(ss, m);
+		m->complete(m->context);
+
+		spin_lock_irqsave(&ss->lock, flags);
+	}
+	spin_unlock_irqrestore(&ss->lock, flags);
+
+	return;
+}
+
+/**
+ * stmp_spi_transfer - perform message transfer.
+ * Called indirectly from spi_async, queues all the messages to
+ * spi_handle_message.
+ * @spi: spi device
+ * @m: message to be queued
+ */
+static int stmp_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->status = -EINPROGRESS;
+	spin_lock_irqsave(&ss->lock, flags);
+	list_add_tail(&m->queue, &ss->queue);
+	queue_work(ss->workqueue, &ss->work);
+	spin_unlock_irqrestore(&ss->lock, flags);
+	return 0;
+}
+
+static irqreturn_t stmp_spi_irq(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	complete(&ss->done);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+	u32 c1, st;
+
+	c1 = readl(ss->regs + HW_SSP_CTRL1);
+	st = readl(ss->regs + HW_SSP_STATUS);
+	dev_err(ss->master_dev, "%s: status = 0x%08X, c1 = 0x%08X\n",
+		__func__, st, c1);
+	stmp3xxx_clearl(c1 & 0xCCCC0000, ss->regs + HW_SSP_CTRL1);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit stmp_spi_probe(struct platform_device *dev)
+{
+	int err = 0;
+	struct spi_master *master;
+	struct stmp_spi *ss;
+	struct resource *r;
+
+	master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
+	if (master == NULL) {
+		err = -ENOMEM;
+		goto out0;
+	}
+	master->flags = SPI_MASTER_HALF_DUPLEX;
+
+	ss = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	/* Get resources(memory, IRQ) associated with the device */
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+	ss->regs = ioremap(r->start, resource_size(r));
+	if (!ss->regs) {
+		err = -EINVAL;
+		goto out_put_master;
+	}
+
+	ss->master_dev = &dev->dev;
+	ss->id = dev->id;
+
+	INIT_WORK(&ss->work, stmp_spi_handle);
+	INIT_LIST_HEAD(&ss->queue);
+	spin_lock_init(&ss->lock);
+
+	ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
+	if (!ss->workqueue) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+	master->transfer = stmp_spi_transfer;
+	master->setup = stmp_spi_setup;
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA;
+
+	ss->irq = platform_get_irq(dev, 0);
+	if (ss->irq < 0) {
+		err = ss->irq;
+		goto out_put_master;
+	}
+	ss->err_irq = platform_get_irq(dev, 1);
+	if (ss->err_irq < 0) {
+		err = ss->err_irq;
+		goto out_put_master;
+	}
+
+	r = platform_get_resource(dev, IORESOURCE_DMA, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+
+	ss->dma = r->start;
+	err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
+	if (err)
+		goto out_put_master;
+
+	err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
+	if (err)
+		goto out_free_dma;
+
+	master->bus_num = dev->id;
+	master->num_chipselect = 1;
+
+	/* SPI controller initializations */
+	err = stmp_spi_init_hw(ss);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot initialize hardware\n");
+		goto out_free_dma_desc;
+	}
+
+	if (clock) {
+		dev_info(&dev->dev, "clock rate forced to %d\n", clock);
+		clk_set_rate(ss->clk, clock);
+	}
+	ss->speed_khz = clk_get_rate(ss->clk);
+	ss->divider = 2;
+	dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
+		ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
+
+	/* Register for SPI interrupt */
+	err = request_irq(ss->irq, stmp_spi_irq, 0,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
+		goto out_release_hw;
+	}
+
+	/* ..and shared interrupt for all SSP controllers */
+	err = request_irq(ss->err_irq, stmp_spi_irq_err, IRQF_SHARED,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
+		goto out_free_irq;
+	}
+
+	err = spi_register_master(master);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot register spi master, %d\n", err);
+		goto out_free_irq_2;
+	}
+	dev_info(&dev->dev, "at (mapped) 0x%08X, irq=%d, bus %d, %s mode\n",
+			(u32)ss->regs, ss->irq, master->bus_num,
+			pio ? "PIO" : "DMA");
+	return 0;
+
+out_free_irq_2:
+	free_irq(ss->err_irq, ss);
+out_free_irq:
+	free_irq(ss->irq, ss);
+out_free_dma_desc:
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+out_free_dma:
+	stmp3xxx_dma_release(ss->dma);
+out_release_hw:
+	stmp_spi_release_hw(ss);
+out_put_master:
+	spi_master_put(master);
+	if (ss->regs)
+		iounmap(ss->regs);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+out0:
+	return err;
+}
+
+static int __devexit stmp_spi_remove(struct platform_device *dev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(dev);
+	if (master == NULL)
+		goto out0;
+	ss = spi_master_get_devdata(master);
+	if (ss == NULL)
+		goto out1;
+	free_irq(ss->err_irq, ss);
+	free_irq(ss->irq, ss);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+	if (ss->regs)
+		iounmap(ss->regs);
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+	stmp3xxx_dma_release(ss->dma);
+	stmp_spi_release_hw(ss);
+	platform_set_drvdata(dev, NULL);
+out1:
+	spi_master_put(master);
+out0:
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int stmp_spi_suspend(struct platform_device *pdev, pm_message_t pmsg)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	ss->saved_timings = readl(HW_SSP_TIMING + ss->regs);
+	clk_disable(ss->clk);
+
+	return 0;
+}
+
+static int stmp_spi_resume(struct platform_device *pdev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	clk_enable(ss->clk);
+	stmp3xxx_reset_block(ss->regs, false);
+	writel(ss->saved_timings, ss->regs + HW_SSP_TIMING);
+
+	return 0;
+}
+
+#else
+#define stmp_spi_suspend NULL
+#define stmp_spi_resume  NULL
+#endif
+
+static struct platform_driver stmp_spi_driver = {
+	.probe	= stmp_spi_probe,
+	.remove	= __devexit_p(stmp_spi_remove),
+	.driver = {
+		.name = "stmp3xxx_ssp",
+		.owner = THIS_MODULE,
+	},
+	.suspend = stmp_spi_suspend,
+	.resume  = stmp_spi_resume,
+};
+
+static int __init stmp_spi_init(void)
+{
+	return platform_driver_register(&stmp_spi_driver);
+}
+
+static void __exit stmp_spi_exit(void)
+{
+	platform_driver_unregister(&stmp_spi_driver);
+}
+
+module_init(stmp_spi_init);
+module_exit(stmp_spi_exit);
+module_param(pio, int, S_IRUGO);
+module_param(clock, int, S_IRUGO);
+MODULE_AUTHOR("dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>");
+MODULE_DESCRIPTION("STMP3xxx SPI/SSP driver");
+MODULE_LICENSE("GPL");



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^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH] Freescale STMP SPI driver
@ 2009-04-29 12:20 dmitry pervushin
  0 siblings, 0 replies; 9+ messages in thread
From: dmitry pervushin @ 2009-04-29 12:20 UTC (permalink / raw)
  To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f

Hello all,

This patch adds SPI bus driver for Freescale STMP 3xxx-based boards

Signed-off-by: dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
---
 drivers/spi/Kconfig    |    6
 drivers/spi/Makefile   |    1
 drivers/spi/spi_stmp.c |  657 +++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/spi/spi_stmp.h |   45 +++
 4 files changed, 709 insertions(+)

Index: linux-2.6-arm/drivers/spi/Kconfig
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Kconfig
+++ linux-2.6-arm/drivers/spi/Kconfig
@@ -204,6 +204,12 @@ config SPI_SH_SCI
 	help
 	  SPI driver for SuperH SCI blocks.
 
+config SPI_STMP3XXX
+	tristate "Freescale STMP37xx/378x SPI/SSP controller"
+	depends on ARCH_STMP3XXX && SPI_MASTER
+	help
+	  SPI driver for Freescale STMP37xx/378x SoC SSP interface
+
 config SPI_TXX9
 	tristate "Toshiba TXx9 SPI controller"
 	depends on GENERIC_GPIO && CPU_TX49XX
Index: linux-2.6-arm/drivers/spi/Makefile
===================================================================
--- linux-2.6-arm.orig/drivers/spi/Makefile
+++ linux-2.6-arm/drivers/spi/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_SPI_S3C24XX)		+= spi_s3c24x
 obj-$(CONFIG_SPI_TXX9)			+= spi_txx9.o
 obj-$(CONFIG_SPI_XILINX)		+= xilinx_spi.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi_sh_sci.o
+obj-$(CONFIG_SPI_STMP3XXX)		+= spi_stmp.o
 # 	... add above this line ...
 
 # SPI protocol drivers (device/link on bus)
Index: linux-2.6-arm/drivers/spi/spi_stmp.c
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/spi/spi_stmp.c
@@ -0,0 +1,657 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <mach/stmp3xxx.h>
+#include <mach/dma.h>
+#include <mach/regs-ssp.h>
+#include <mach/regs-apbh.h>
+#include "spi_stmp.h"
+
+/* 0 means DMA mode(recommended, default), !0 - PIO mode */
+static int pio;
+static int debug;
+static int clock;
+
+/**
+ * stmp_spi_init_hw
+ *
+ * Initialize the SSP port
+ */
+static int stmp_spi_init_hw(struct stmp_spi *ss)
+{
+	int err = 0;
+	void *pins = ss->master_dev->platform_data;
+
+	err = stmp3xxx_request_pin_group(pins, dev_name(ss->master_dev));
+	if (err)
+		goto out;
+
+	ss->clk = clk_get(NULL, "ssp");
+	if (IS_ERR(ss->clk)) {
+		err = PTR_ERR(ss->clk);
+		goto out_free_pins;
+	}
+	clk_enable(ss->clk);
+
+	stmp3xxx_reset_block(ss->regs, 0);
+	stmp3xxx_dma_reset_channel(ss->dma);
+
+	return 0;
+
+out_free_pins:
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+out:
+	return err;
+}
+
+static void stmp_spi_release_hw(struct stmp_spi *ss)
+{
+	void *pins = ss->master_dev->platform_data;
+
+	if (ss->clk && !IS_ERR(ss->clk)) {
+		clk_disable(ss->clk);
+		clk_put(ss->clk);
+	}
+	stmp3xxx_release_pin_group(pins, dev_name(ss->master_dev));
+}
+
+static int stmp_spi_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	u8 bits_per_word;
+	u32 hz;
+	struct stmp_spi *ss /* = spi_master_get_devdata(spi->master) */;
+	u16 rate;
+
+	ss = spi_master_get_devdata(spi->master);
+
+	bits_per_word = spi->bits_per_word;
+	if (t && t->bits_per_word)
+		bits_per_word = t->bits_per_word;
+
+	/*
+	  Calculate speed:
+		- by default, use maximum speed from ssp clk
+		- if device overrides it, use it
+		- if transfer specifies other speed, use transfer's one
+	 */
+	hz = 1000 * ss->speed_khz / ss->divider;
+	if (spi->max_speed_hz)
+		hz = min(hz, spi->max_speed_hz);
+	if (t && t->speed_hz)
+		hz = min(hz, t->speed_hz);
+
+	if (hz == 0) {
+		dev_err(&spi->dev, "Cannot continue with zero clock\n");
+		return -EINVAL;
+	}
+
+	if (bits_per_word != 8) {
+		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
+			__func__, bits_per_word);
+		return -EINVAL;
+	}
+
+	dev_dbg(&spi->dev, "Requested clk rate = %uHz, max = %uHz/%d = %uHz\n",
+		hz, ss->speed_khz, ss->divider,
+		ss->speed_khz * 1000 / ss->divider);
+
+	if (ss->speed_khz * 1000 / ss->divider < hz) {
+		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
+			__func__, hz);
+		return -EINVAL;
+	}
+
+	rate = 1000 * ss->speed_khz/ss->divider/hz;
+
+	HW_SSP_TIMING_WR_NB(ss->regs,
+		BF_SSP_TIMING_CLOCK_DIVIDE(ss->divider) |
+		BF_SSP_TIMING_CLOCK_RATE(rate - 1));
+
+	HW_SSP_CTRL1_WR_NB(ss->regs,
+		BF_SSP_CTRL1_SSP_MODE(BV_SSP_CTRL1_SSP_MODE__SPI) |
+		BF_SSP_CTRL1_WORD_LENGTH(BV_SSP_CTRL1_WORD_LENGTH__EIGHT_BITS) |
+		((spi->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
+		((spi->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0) |
+		(pio ? 0 : BM_SSP_CTRL1_DMA_ENABLE));
+
+	HW_SSP_CMD0_SET(0x00);
+
+	return 0;
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA)
+static int stmp_spi_setup(struct spi_device *spi)
+{
+	struct stmp_spi *ss;
+
+	ss = spi_master_get_devdata(spi->master);
+	if (!spi->bits_per_word)
+		spi->bits_per_word = 8;
+	if (spi->mode & ~MODEBITS) {
+		dev_err(&spi->dev, "%s: unsupported mode bits %x\n",
+			__func__, spi->mode & ~MODEBITS);
+		return -EINVAL;
+	}
+	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w\n",
+		__func__, spi->mode & MODEBITS, spi->bits_per_word);
+	return stmp_spi_setup_transfer(spi, NULL);
+}
+
+static inline u32 stmp_spi_cs(unsigned cs)
+{
+	return  ((cs & 1) ? BM_SSP_CTRL0_WAIT_FOR_CMD : 0) |
+		((cs & 2) ? BM_SSP_CTRL0_WAIT_FOR_IRQ : 0);
+}
+
+static int stmp_spi_txrx_dma(struct stmp_spi *ss, int cs,
+		unsigned char *buf, dma_addr_t dma_buf, int len,
+		int *first, int *last, int write)
+{
+	u32 c0 = 0;
+	dma_addr_t spi_buf_dma = dma_buf;
+	int count, status = 0;
+	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+
+	c0 |= (*first ? BM_SSP_CTRL0_LOCK_CS : 0);
+	c0 |= (*last ? BM_SSP_CTRL0_IGNORE_CRC : 0);
+	c0 |= (write ? 0 : BM_SSP_CTRL0_READ);
+	c0 |= BM_SSP_CTRL0_DATA_XFER;
+
+	c0 |= stmp_spi_cs(cs);
+
+	c0 |= BF_SSP_CTRL0_XFER_COUNT(len);
+
+	if (!dma_buf)
+		spi_buf_dma = dma_map_single(ss->master_dev, buf, len, dir);
+
+	ss->d.command->cmd =
+		BF_APBH_CHn_CMD_XFER_COUNT(len) |
+		BF_APBH_CHn_CMD_CMDWORDS(1) |
+		BM_APBH_CHn_CMD_WAIT4ENDCMD |
+		BM_APBH_CHn_CMD_IRQONCMPLT  |
+		BF_APBH_CHn_CMD_COMMAND(
+			write ? BV_APBH_CHn_CMD_COMMAND__DMA_READ :
+				BV_APBH_CHn_CMD_COMMAND__DMA_WRITE);
+	ss->d.command->pio_words[0] = c0;
+	ss->d.command->buf_ptr = spi_buf_dma;
+
+	stmp3xxx_dma_reset_channel(ss->dma);
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	stmp3xxx_dma_enable_interrupt(ss->dma);
+	init_completion(&ss->done);
+	stmp3xxx_dma_go(ss->dma, &ss->d, 1);
+	wait_for_completion(&ss->done);
+	count = 10000;
+	while ((HW_SSP_CTRL0_RD() & BM_SSP_CTRL0_RUN) && count--)
+		continue;
+	if (count <= 0)
+		status = -ETIMEDOUT;
+
+	if (!dma_buf)
+		dma_unmap_single(ss->master_dev, spi_buf_dma, len, dir);
+
+	return status;
+}
+
+static inline void stmp_spi_enable(struct stmp_spi *ss)
+{
+	HW_SSP_CTRL0_SET_NB(ss->regs, BM_SSP_CTRL0_LOCK_CS);
+	HW_SSP_CTRL0_CLR_NB(ss->regs, BM_SSP_CTRL0_IGNORE_CRC);
+}
+
+static inline void stmp_spi_disable(struct stmp_spi *ss)
+{
+	HW_SSP_CTRL0_CLR_NB(ss->regs, BM_SSP_CTRL0_LOCK_CS);
+	HW_SSP_CTRL0_SET_NB(ss->regs, BM_SSP_CTRL0_IGNORE_CRC);
+}
+
+static int stmp_spi_txrx_pio(struct stmp_spi *ss, int cs,
+		unsigned char *buf, int len,
+		int *first, int *last, int write)
+{
+	int count;
+
+	if (*first) {
+		stmp_spi_enable(ss);
+		*first = 0;
+	}
+
+	HW_SSP_CTRL0_SET(stmp_spi_cs(cs));
+
+	while (len--) {
+		if (*last && len == 0) {
+			stmp_spi_disable(ss);
+			*last = 0;
+		}
+		HW_SSP_CTRL0_CLR_NB(ss->regs, BM_SSP_CTRL0_XFER_COUNT);
+		HW_SSP_CTRL0_SET_NB(ss->regs, 1); /* byte-by-byte */
+
+		if (write)
+			HW_SSP_CTRL0_CLR_NB(ss->regs, BM_SSP_CTRL0_READ);
+		else
+			HW_SSP_CTRL0_SET_NB(ss->regs, BM_SSP_CTRL0_READ);
+
+		/* Run! */
+		HW_SSP_CTRL0_SET_NB(ss->regs, BM_SSP_CTRL0_RUN);
+		count = 10000;
+		while (((HW_SSP_CTRL0_RD() & BM_SSP_CTRL0_RUN) == 0) && count--)
+			continue;
+		if (count <= 0)
+			break;
+
+		if (write)
+			HW_SSP_DATA_WR_NB(ss->regs, *buf);
+
+		/* Set TRANSFER */
+		HW_SSP_CTRL0_SET_NB(ss->regs, BM_SSP_CTRL0_DATA_XFER);
+
+		if (!write) {
+			count = 10000;
+			while (count-- &&
+				(HW_SSP_STATUS_RD_NB(ss->regs) &
+					BM_SSP_STATUS_FIFO_EMPTY))
+				continue;
+			if (count <= 0)
+				break;
+			*buf = (HW_SSP_DATA_RD_NB(ss->regs) & 0xFF);
+		}
+
+		count = 10000;
+		while ((HW_SSP_CTRL0_RD() & BM_SSP_CTRL0_RUN) && count--)
+			continue;
+		if (count <= 0)
+			break;
+
+		/* advance to the next byte */
+		buf++;
+	}
+	return len < 0 ? 0 : -ETIMEDOUT;
+}
+
+static int stmp_spi_handle_message(struct stmp_spi *ss, struct spi_message *m)
+{
+	int first, last;
+	struct spi_transfer *t, *tmp_t;
+	int status = 0;
+	int cs;
+
+	first = last = 0;
+
+	cs = m->spi->chip_select;
+
+	list_for_each_entry_safe(t, tmp_t, &m->transfers, transfer_list) {
+
+		stmp_spi_setup_transfer(m->spi, t);
+
+		if (&t->transfer_list == m->transfers.next)
+			first = !0;
+		if (&t->transfer_list == m->transfers.prev)
+			last = !0;
+		if (t->rx_buf && t->tx_buf) {
+			pr_debug("%s: cannot send and receive simultaneously\n",
+				__func__);
+			return -EINVAL;
+		}
+
+		/*
+		  REVISIT:
+		  here driver completely ignores setting of t->cs_change
+		 */
+		if (t->tx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, (void *)t->tx_buf,
+				   t->len, &first, &last, 1) :
+			   stmp_spi_txrx_dma(ss, cs, (void *)t->tx_buf,
+				   t->tx_dma, t->len, &first, &last, 1);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Tx ",
+						DUMP_PREFIX_OFFSET,
+						t->tx_buf, t->len);
+				else
+					pr_debug("Tx: %d bytes\n", t->len);
+			}
+		}
+		if (t->rx_buf) {
+			status = pio ?
+			   stmp_spi_txrx_pio(ss, cs, t->rx_buf,
+				   t->len, &first, &last, 0) :
+			   stmp_spi_txrx_dma(ss, cs, t->rx_buf,
+				   t->rx_dma, t->len, &first, &last, 0);
+			if (debug) {
+				if (t->len < 0x10)
+					print_hex_dump_bytes("Rx ",
+						DUMP_PREFIX_OFFSET,
+						t->rx_buf, t->len);
+				else
+					pr_debug("Rx: %d bytes\n", t->len);
+			}
+		}
+
+		if (status)
+			break;
+
+		first = last = 0;
+
+	}
+	return status;
+}
+
+/**
+ * stmp_spi_handle - handle messages from the queue
+ */
+static void stmp_spi_handle(struct work_struct *w)
+{
+	struct stmp_spi *ss = container_of(w, struct stmp_spi, work);
+	unsigned long flags;
+	struct spi_message *m;
+
+	BUG_ON(w == NULL);
+
+	spin_lock_irqsave(&ss->lock, flags);
+	while (!list_empty(&ss->queue)) {
+		m = list_entry(ss->queue.next, struct spi_message, queue);
+		list_del_init(&m->queue);
+		spin_unlock_irqrestore(&ss->lock, flags);
+
+		m->status = stmp_spi_handle_message(ss, m);
+		if (m->complete)
+			m->complete(m->context);
+
+		spin_lock_irqsave(&ss->lock, flags);
+	}
+	spin_unlock_irqrestore(&ss->lock, flags);
+
+	return;
+}
+
+/**
+ * stmp_spi_transfer - perform message transfer.
+ * Called indirectly from spi_async, queues all the messages to
+ * spi_handle_message.
+ * @spi: spi device
+ * @m: message to be queued
+**/
+static int stmp_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+	struct stmp_spi *ss = spi_master_get_devdata(spi->master);
+	unsigned long flags;
+
+	m->status = -EINPROGRESS;
+	spin_lock_irqsave(&ss->lock, flags);
+	list_add_tail(&m->queue, &ss->queue);
+	queue_work(ss->workqueue, &ss->work);
+	spin_unlock_irqrestore(&ss->lock, flags);
+	return 0;
+}
+
+static irqreturn_t stmp_spi_irq(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+
+	stmp3xxx_dma_clear_interrupt(ss->dma);
+	complete(&ss->done);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stmp_spi_irq_err(int irq, void *dev_id)
+{
+	struct stmp_spi *ss = dev_id;
+	u32 c1, st;
+
+	c1 = HW_SSP_CTRL1_RD_NB(ss->regs);
+	st = HW_SSP_STATUS_RD_NB(ss->regs);
+	printk(KERN_ERR"IRQ - ERROR!, status = 0x%08X, c1 = 0x%08X\n", st, c1);
+	HW_SSP_CTRL1_CLR_NB(ss->regs, c1 & 0xCCCC0000);
+
+	return IRQ_HANDLED;
+}
+
+static int __init stmp_spi_probe(struct platform_device *dev)
+{
+	int err = 0;
+	struct spi_master *master;
+	struct stmp_spi *ss;
+	struct resource *r;
+
+	/* Get resources(memory, IRQ) associated with the device */
+	master = spi_alloc_master(&dev->dev, sizeof(struct stmp_spi));
+
+	if (master == NULL) {
+		err = -ENOMEM;
+		goto out0;
+	}
+
+	ss = spi_master_get_devdata(master);
+	platform_set_drvdata(dev, master);
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+	ss->regs = ioremap(r->start, resource_size(r));
+	if (!ss->regs) {
+		err = -EINVAL;
+		goto out_put_master;
+	}
+
+	ss->master_dev = &dev->dev;
+	ss->id = dev->id;
+
+	INIT_WORK(&ss->work, stmp_spi_handle);
+	INIT_LIST_HEAD(&ss->queue);
+	spin_lock_init(&ss->lock);
+
+	ss->workqueue = create_singlethread_workqueue(dev_name(&dev->dev));
+	if (!ss->workqueue) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+	master->transfer = stmp_spi_transfer;
+	master->setup = stmp_spi_setup;
+
+
+	ss->irq = platform_get_irq(dev, 0);
+	if (ss->irq < 0) {
+		err = -ENXIO;
+		goto out_put_master;
+	}
+
+	r = platform_get_resource(dev, IORESOURCE_DMA, 0);
+	if (r == NULL) {
+		err = -ENODEV;
+		goto out_put_master;
+	}
+
+	ss->dma = r->start;
+	err = stmp3xxx_dma_request(ss->dma, &dev->dev, dev_name(&dev->dev));
+	if (err)
+		goto out_put_master;
+
+	err = stmp3xxx_dma_allocate_command(ss->dma, &ss->d);
+	if (err)
+		goto out_free_dma;
+
+	master->bus_num = dev->id;
+	master->num_chipselect = 1;
+
+	/* SPI controller initializations */
+	err = stmp_spi_init_hw(ss);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot initialize hardware\n");
+		goto out_free_dma_desc;
+	}
+
+	if (clock) {
+		dev_info(&dev->dev, "clock rate forced to %d\n", clock);
+		clk_set_rate(ss->clk, clock);
+	}
+	ss->speed_khz = clk_get_rate(ss->clk);
+	ss->divider = 2;
+	dev_info(&dev->dev, "max possible speed %d = %ld/%d kHz\n",
+		ss->speed_khz, clk_get_rate(ss->clk), ss->divider);
+
+	/* Register for SPI interrupt */
+	err = request_irq(ss->irq, stmp_spi_irq, 0,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq failed, %d\n", err);
+		goto out_release_hw;
+	}
+
+	/* ..and shared interrupt for all SSP controllers */
+	err = request_irq(IRQ_SSP_ERROR, stmp_spi_irq_err, IRQF_SHARED,
+			  dev_name(&dev->dev), ss);
+	if (err) {
+		dev_dbg(&dev->dev, "request_irq(error) failed, %d\n", err);
+		goto out_free_irq;
+	}
+
+	err = spi_register_master(master);
+	if (err) {
+		dev_dbg(&dev->dev, "cannot register spi master, %d\n", err);
+		goto out_free_irq_2;
+	}
+	dev_info(&dev->dev, "at (mapped) 0x%08X, irq=%d, bus %d, %s mode\n",
+			(u32)ss->regs, ss->irq, master->bus_num,
+			pio ? "PIO" : "DMA");
+	return 0;
+
+out_free_irq_2:
+	free_irq(IRQ_SSP_ERROR, ss);
+out_free_irq:
+	free_irq(ss->irq, ss);
+out_free_dma_desc:
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+out_free_dma:
+	stmp3xxx_dma_release(ss->dma);
+out_release_hw:
+	stmp_spi_release_hw(ss);
+out_put_master:
+	spi_master_put(master);
+	if (ss->regs)
+		iounmap(ss->regs);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+out0:
+	return err;
+}
+
+static int __devexit stmp_spi_remove(struct platform_device *dev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(dev);
+	if (master == NULL)
+		goto out0;
+	ss = spi_master_get_devdata(master);
+	if (ss == NULL)
+		goto out1;
+	free_irq(ss->irq, ss);
+	if (ss->workqueue)
+		destroy_workqueue(ss->workqueue);
+	if (ss->regs)
+		iounmap(ss->regs);
+	stmp3xxx_dma_free_command(ss->dma, &ss->d);
+	stmp3xxx_dma_release(ss->dma);
+	stmp_spi_release_hw(ss);
+	platform_set_drvdata(dev, NULL);
+out1:
+	spi_master_put(master);
+out0:
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int stmp_spi_suspend(struct platform_device *pdev, pm_message_t pmsg)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	ss->saved_timings = HW_SSP_TIMING_RD_NB(ss->regs);
+	clk_disable(ss->clk);
+
+	return 0;
+}
+
+static int stmp_spi_resume(struct platform_device *pdev)
+{
+	struct stmp_spi *ss;
+	struct spi_master *master;
+
+	master = platform_get_drvdata(pdev);
+	ss = spi_master_get_devdata(master);
+
+	clk_enable(ss->clk);
+	HW_SSP_CTRL0_CLR_NB(ss->regs,
+		BM_SSP_CTRL0_SFTRST | BM_SSP_CTRL0_CLKGATE);
+	HW_SSP_TIMING_SET_NB(ss->regs, ss->saved_timings);
+
+	return 0;
+}
+
+#else
+#define stmp_spi_suspend NULL
+#define stmp_spi_resume  NULL
+#endif
+
+static struct platform_driver stmp_spi_driver = {
+	.probe	= stmp_spi_probe,
+	.remove	= __devexit_p(stmp_spi_remove),
+	.driver = {
+		.name = "stmp37xx_ssp",
+		.owner = THIS_MODULE,
+	},
+	.suspend = stmp_spi_suspend,
+	.resume  = stmp_spi_resume,
+};
+
+static int __init stmp_spi_init(void)
+{
+	return platform_driver_register(&stmp_spi_driver);
+}
+
+static void __exit stmp_spi_exit(void)
+{
+	platform_driver_unregister(&stmp_spi_driver);
+}
+
+module_init(stmp_spi_init);
+module_exit(stmp_spi_exit);
+module_param(pio, int, S_IRUGO);
+module_param(debug, int, 0644);
+module_param(clock, int, S_IRUGO);
+MODULE_AUTHOR("dmitry pervushin <dpervushin-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>");
+MODULE_DESCRIPTION("STMP3xxx SPI/SSP driver");
+MODULE_LICENSE("GPL");
Index: linux-2.6-arm/drivers/spi/spi_stmp.h
===================================================================
--- /dev/null
+++ linux-2.6-arm/drivers/spi/spi_stmp.h
@@ -0,0 +1,45 @@
+/*
+ * Freescale STMP378X SPI master driver
+ *
+ * Author: dmitry pervushin <dimka-L1vi/lXTdtvkgf6YlCu6wwC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#ifndef __SPI_STMP_H
+#define __SPI_STMP_H
+
+struct stmp_spi {
+	int		id;
+
+	void *  __iomem regs;	/* vaddr of the control registers */
+
+	u32		irq;
+	u32		dma;
+	struct stmp3xxx_dma_descriptor d;
+
+	u32		speed_khz;
+	u32		saved_timings;
+	u32		divider;
+
+	struct clk	*clk;
+	struct device	*master_dev;
+
+	struct work_struct work;
+	struct workqueue_struct *workqueue;
+	spinlock_t lock;
+	struct list_head queue;
+
+	struct completion done;
+};
+
+#endif /* __SPI_STMP_H */



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^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2009-07-07 14:14 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-06-02 19:40 [PATCH] Freescale STMP spi driver dmitry pervushin
     [not found] ` <1243971638.4011.16.camel-GL0tbJR47UuzLY3athcO2A@public.gmane.org>
2009-06-03  4:27   ` Baruch Siach
2009-06-03 16:15     ` [PATCH] Freescale STMP spi driver, revised dmitry pervushin
     [not found]       ` <1244045746.4074.5.camel-GL0tbJR47UuzLY3athcO2A@public.gmane.org>
2009-07-03  4:47         ` David Brownell
     [not found]           ` <200907022147.44892.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2009-07-03 10:23             ` dmitry pervushin
2009-07-03 10:24             ` [PATCH] Freescale STMP spi driver - take 3 dmitry pervushin
2009-07-03  7:02         ` [PATCH] Freescale STMP spi driver, revised David Brownell
     [not found]           ` <200907031849.53761.david-b@pacbell.net>
     [not found]             ` <200907031849.53761.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
2009-07-07 14:14               ` dmitry pervushin
  -- strict thread matches above, loose matches on Subject: below --
2009-04-29 12:20 [PATCH] Freescale STMP SPI driver dmitry pervushin

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