[PATCH v6 0/2] Add spi control driver for Sunplus SP7021 SoC

[PATCH v6 0/2] Add spi control driver for Sunplus SP7021 SoC

[Li-hao Kuo]

This is a patch series for SPI driver for Sunplus SP7021 SoC.

Sunplus SP7021 is an ARM Cortex A7 (4 cores) based SoC. It integrates
many peripherals (ex: UART, I2C, SPI, SDIO, eMMC, USB, SD card and
etc.) into a single chip. It is designed for industrial control.

Refer to:
https://sunplus-tibbo.atlassian.net/wiki/spaces/doc/overview
https://tibbo.com/store/plus1.html

Li-hao Kuo (2):
  spi: Add spi driver for Sunplus SP7021
  dt-bindings:spi: Add Sunplus SP7021 schema

 .../bindings/spi/spi-sunplus-sp7021.yaml           |  81 +++
 MAINTAINERS                                        |   7 +
 drivers/spi/Kconfig                                |  11 +
 drivers/spi/Makefile                               |   1 +
 drivers/spi/spi-sunplus-sp7021.c                   | 602 +++++++++++++++++++++
 5 files changed, 702 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml
 create mode 100644 drivers/spi/spi-sunplus-sp7021.c

-- 
2.7.4

[PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Li-hao Kuo]

Add spi driver for Sunplus SP7021.

Signed-off-by: Li-hao Kuo <lhjeff911@gmail.com>
---
Changes in v6:
 - Change the interrupt-names 
   mas_risc to master_risc
 - Addressed comments from Mr. Andy Shevchenko
   Change the function name: mas is master and sla is slave.
   Add temporary varilable (as suggested by Mr. Andy Shevchenko)
   Modify clk setting
   Modify the master-slave detection of the probe function.(as suggested by Mr. Andy Shevchenko)
   Modify the return value of the probe function.(as suggested by Mr. Andy Shevchenko)
   Change GPL version(as suggested by Mr. Andy Shevchenko)

 MAINTAINERS                      |   6 +
 drivers/spi/Kconfig              |  11 +
 drivers/spi/Makefile             |   1 +
 drivers/spi/spi-sunplus-sp7021.c | 602 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 620 insertions(+)
 create mode 100644 drivers/spi/spi-sunplus-sp7021.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a58544f..a07da20 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18493,6 +18493,12 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/dlink/sundance.c
 
+SUNPLUS SPI CONTROLLER INTERFACE DRIVER
+M:	Li-hao Kuo <lhjeff911@gmail.com>
+L:	linux-spi@vger.kernel.org
+S:	Maintained
+F:	drivers/spi/spi-sunplus-sp7021.c
+
 SUPERH
 M:	Yoshinori Sato <ysato@users.sourceforge.jp>
 M:	Rich Felker <dalias@libc.org>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index b2a8821..203f4ec 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -866,6 +866,17 @@ config SPI_SUN6I
 	help
 	  This enables using the SPI controller on the Allwinner A31 SoCs.
 
+config SPI_SUNPLUS_SP7021
+	tristate "Sunplus SP7021 SPI controller"
+	depends on SOC_SP7021 || COMPILE_TEST
+	help
+	  This enables Sunplus SP7021 SPI controller driver on the SP7021 SoCs.
+	  This driver can also be built as a module. If so, the module will be
+	  called as spi-sunplus-sp7021.
+
+	  If you have a  Sunplus SP7021 platform say Y here.
+	  If unsure, say N.
+
 config SPI_SYNQUACER
 	tristate "Socionext's SynQuacer HighSpeed SPI controller"
 	depends on ARCH_SYNQUACER || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index dd7393a..b455eaf 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -119,6 +119,7 @@ obj-$(CONFIG_SPI_STM32_QSPI) 		+= spi-stm32-qspi.o
 obj-$(CONFIG_SPI_ST_SSC4)		+= spi-st-ssc4.o
 obj-$(CONFIG_SPI_SUN4I)			+= spi-sun4i.o
 obj-$(CONFIG_SPI_SUN6I)			+= spi-sun6i.o
+obj-$(CONFIG_SPI_SUNPLUS_SP7021)	+= spi-sunplus-sp7021.o
 obj-$(CONFIG_SPI_SYNQUACER)		+= spi-synquacer.o
 obj-$(CONFIG_SPI_TEGRA210_QUAD)		+= spi-tegra210-quad.o
 obj-$(CONFIG_SPI_TEGRA114)		+= spi-tegra114.o
diff --git a/drivers/spi/spi-sunplus-sp7021.c b/drivers/spi/spi-sunplus-sp7021.c
new file mode 100644
index 0000000..627b9c3
--- /dev/null
+++ b/drivers/spi/spi-sunplus-sp7021.c
@@ -0,0 +1,602 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2021 Sunplus Inc.
+// Author: Li-hao Kuo <lhjeff911@gmail.com>
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/spi/spi.h>
+
+#define SP7021_DATA_RDY_REG		0x0044
+#define SP7021_SLAVE_DMA_CTRL_REG	0x0048
+#define SP7021_SLAVE_DMA_LENGTH_REG	0x004c
+#define SP7021_SLAVE_DMA_ADDR_REG	0x004c
+
+#define SP7021_SLAVE_DATA_RDY		BIT(0)
+#define SP7021_SLAVE_SW_RST		BIT(1)
+#define SP7021_SLA_DMA_W_INT		BIT(8)
+#define SP7021_SLAVE_CLR_INT		BIT(8)
+#define SP7021_SLAVE_DMA_EN		BIT(0)
+#define SP7021_SLAVE_DMA_RW		BIT(6)
+#define SP7021_SLAVE_DMA_CMD		GENMASK(3, 2)
+
+#define SP7021_FIFO_REG			0x0034
+#define SP7021_SPI_STATUS_REG		0x0038
+#define SP7021_SPI_CONFIG_REG		0x003c
+#define SP7021_INT_BUSY_REG		0x004c
+#define SP7021_DMA_CTRL_REG		0x0050
+
+#define SP7021_SPI_START_FD		BIT(0)
+#define SP7021_FD_SW_RST		BIT(1)
+#define SP7021_TX_EMP_FLAG		BIT(2)
+#define SP7021_RX_EMP_FLAG		BIT(4)
+#define SP7021_RX_FULL_FLAG		BIT(5)
+#define SP7021_FINISH_FLAG		BIT(6)
+
+#define SP7021_TX_CNT_MASK		GENMASK(11, 8)
+#define SP7021_RX_CNT_MASK		GENMASK(15, 12)
+#define SP7021_TX_LEN_MASK		GENMASK(23, 16)
+#define SP7021_GET_LEN_MASK		GENMASK(31, 24)
+#define SP7021_SET_TX_LEN		GENMASK(23, 16)
+#define SP7021_SET_XFER_LEN		GENMASK(31, 24)
+
+#define SP7021_CPOL_FD			BIT(0)
+#define SP7021_CPHA_R			BIT(1)
+#define SP7021_CPHA_W			BIT(2)
+#define SP7021_LSB_SEL			BIT(4)
+#define SP7021_CS_POR			BIT(5)
+#define SP7021_FD_SEL			BIT(6)
+
+#define SP7021_RX_UNIT			GENMASK(8, 7)
+#define SP7021_TX_UNIT			GENMASK(10, 9)
+#define SP7021_TX_EMP_FLAG_MASK		BIT(11)
+#define SP7021_RX_FULL_FLAG_MASK	BIT(14)
+#define SP7021_FINISH_FLAG_MASK		BIT(15)
+#define SP7021_CLEAN_RW_BYTE		GENMASK(10, 7)
+#define SP7021_CLEAN_FLUG_MASK		GENMASK(15, 11)
+#define SP7021_CLK_MASK			GENMASK(31, 16)
+
+#define SP7021_INT_BYPASS		BIT(3)
+#define SP7021_CLR_MASTER_INT		BIT(6)
+
+#define SP7021_SPI_DATA_SIZE		(255)
+#define SP7021_FIFO_DATA_LEN		(16)
+
+enum SP_SPI_MODE {
+	SP7021_SLAVE_READ = 0,
+	SP7021_SLAVE_WRITE = 1,
+	SP7021_SPI_IDLE = 2,
+};
+
+enum {
+	SP7021_MASTER_MODE = 0,
+	SP7021_SLAVE_MODE = 1,
+};
+
+struct sp7021_spi_ctlr {
+	struct device *dev;
+	struct spi_controller *ctlr;
+	void __iomem *m_base;
+	void __iomem *s_base;
+	u32 xfer_conf;
+	int mode;
+	int m_irq;
+	int s_irq;
+	struct clk *spi_clk;
+	struct reset_control *rstc;
+	// irq spin lock
+	spinlock_t lock;
+	// data xfer lock
+	struct mutex buf_lock;
+	struct completion isr_done;
+	struct completion slave_isr;
+	unsigned int  rx_cur_len;
+	unsigned int  tx_cur_len;
+	unsigned int  data_unit;
+	const u8 *tx_buf;
+	u8 *rx_buf;
+};
+
+static irqreturn_t sp7021_spi_slave_irq(int irq, void *dev)
+{
+	struct sp7021_spi_ctlr *pspim = dev;
+	unsigned int data_status;
+
+	data_status = readl(pspim->s_base + SP7021_DATA_RDY_REG);
+	writel(data_status | SP7021_SLAVE_CLR_INT, pspim->s_base + SP7021_DATA_RDY_REG);
+	complete(&pspim->slave_isr);
+	return IRQ_HANDLED;
+}
+
+static int sp7021_spi_slave_abort(struct spi_controller *ctlr)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	complete(&pspim->slave_isr);
+	complete(&pspim->isr_done);
+	return 0;
+}
+
+int sp7021_spi_slave_tx(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_controller_get_devdata(spi->controller);
+
+	reinit_completion(&pspim->slave_isr);
+	writel(SP7021_SLAVE_DMA_EN | SP7021_SLAVE_DMA_RW | FIELD_PREP(SP7021_SLAVE_DMA_CMD, 3),
+	       pspim->s_base + SP7021_SLAVE_DMA_CTRL_REG);
+	writel(xfer->len, pspim->s_base + SP7021_SLAVE_DMA_LENGTH_REG);
+	writel(xfer->tx_dma, pspim->s_base + SP7021_SLAVE_DMA_ADDR_REG);
+	writel(readl(pspim->s_base + SP7021_DATA_RDY_REG) | SP7021_SLAVE_DATA_RDY,
+	       pspim->s_base + SP7021_DATA_RDY_REG);
+	if (wait_for_completion_interruptible(&pspim->isr_done)) {
+		dev_err(&spi->dev, "%s() wait_for_completion err\n", __func__);
+		return -EINTR;
+	}
+	return 0;
+}
+
+int sp7021_spi_slave_rx(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_controller_get_devdata(spi->controller);
+	int ret = 0;
+
+	reinit_completion(&pspim->isr_done);
+	writel(SP7021_SLAVE_DMA_EN | FIELD_PREP(SP7021_SLAVE_DMA_CMD, 3),
+	       pspim->s_base + SP7021_SLAVE_DMA_CTRL_REG);
+	writel(xfer->len, pspim->s_base + SP7021_SLAVE_DMA_LENGTH_REG);
+	writel(xfer->rx_dma, pspim->s_base + SP7021_SLAVE_DMA_ADDR_REG);
+	if (wait_for_completion_interruptible(&pspim->isr_done)) {
+		dev_err(&spi->dev, "%s() wait_for_completion err\n", __func__);
+		return -EINTR;
+	}
+	writel(SP7021_SLAVE_SW_RST, pspim->s_base + SP7021_SLAVE_DMA_CTRL_REG);
+	return ret;
+}
+
+void sp7021_spi_master_rb(struct sp7021_spi_ctlr *pspim, unsigned int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		pspim->rx_buf[pspim->rx_cur_len] =
+			readl(pspim->m_base + SP7021_FIFO_REG);
+		pspim->rx_cur_len++;
+	}
+}
+
+void sp7021_spi_master_wb(struct sp7021_spi_ctlr *pspim, unsigned int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		writel(pspim->tx_buf[pspim->tx_cur_len],
+		       pspim->m_base + SP7021_FIFO_REG);
+		pspim->tx_cur_len++;
+	}
+}
+
+static irqreturn_t sp7021_spi_master_irq(int irq, void *dev)
+{
+	struct sp7021_spi_ctlr *pspim = dev;
+	unsigned int tx_cnt, total_len;
+	unsigned int tx_len, rx_cnt;
+	unsigned int fd_status;
+	unsigned long flags;
+	bool isrdone = false;
+	u32 value;
+
+	fd_status = readl(pspim->m_base + SP7021_SPI_STATUS_REG);
+	tx_cnt = FIELD_GET(SP7021_TX_CNT_MASK, fd_status);
+	tx_len = FIELD_GET(SP7021_TX_LEN_MASK, fd_status);
+	total_len = FIELD_GET(SP7021_GET_LEN_MASK, fd_status);
+
+	if ((fd_status & SP7021_TX_EMP_FLAG) && (fd_status & SP7021_RX_EMP_FLAG) && total_len == 0)
+		return IRQ_NONE;
+
+	if (tx_len == 0 && total_len == 0)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&pspim->lock, flags);
+
+	rx_cnt = FIELD_GET(SP7021_RX_CNT_MASK, fd_status);
+	if (fd_status & SP7021_RX_FULL_FLAG)
+		rx_cnt = pspim->data_unit;
+
+	tx_cnt = min(tx_len - pspim->tx_cur_len, pspim->data_unit - tx_cnt);
+	dev_dbg(pspim->dev, "fd_st=0x%x rx_c:%d tx_c:%d tx_l:%d",
+		fd_status, rx_cnt, tx_cnt, tx_len);
+
+	if (rx_cnt > 0)
+		sp7021_spi_master_rb(pspim, rx_cnt);
+	if (tx_cnt > 0)
+		sp7021_spi_master_wb(pspim, tx_cnt);
+
+	fd_status = readl(pspim->m_base + SP7021_SPI_STATUS_REG);
+	tx_len = FIELD_GET(SP7021_TX_LEN_MASK, fd_status);
+	total_len = FIELD_GET(SP7021_GET_LEN_MASK, fd_status);
+
+	if (fd_status & SP7021_FINISH_FLAG || tx_len == pspim->tx_cur_len) {
+		while (total_len != pspim->rx_cur_len) {
+			fd_status = readl(pspim->m_base + SP7021_SPI_STATUS_REG);
+			total_len = FIELD_GET(SP7021_GET_LEN_MASK, fd_status);
+			if (fd_status & SP7021_RX_FULL_FLAG)
+				rx_cnt = pspim->data_unit;
+			else
+				rx_cnt = FIELD_GET(SP7021_RX_CNT_MASK, fd_status);
+
+			if (rx_cnt > 0)
+				sp7021_spi_master_rb(pspim, rx_cnt);
+		}
+		value = readl(pspim->m_base + SP7021_INT_BUSY_REG);
+		value |= SP7021_CLR_MASTER_INT;
+		writel(value, pspim->m_base + SP7021_INT_BUSY_REG);
+		writel(SP7021_FINISH_FLAG, pspim->m_base + SP7021_SPI_STATUS_REG);
+		isrdone = true;
+	}
+
+	if (isrdone)
+		complete(&pspim->isr_done);
+	spin_unlock_irqrestore(&pspim->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static void sp7021_prep_transfer(struct spi_controller *ctlr, struct spi_device *spi)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	pspim->tx_cur_len = 0;
+	pspim->rx_cur_len = 0;
+	pspim->data_unit = SP7021_FIFO_DATA_LEN;
+}
+
+// preliminary set CS, CPOL, CPHA and LSB
+static int sp7021_spi_controller_prepare_message(struct spi_controller *ctlr,
+						 struct spi_message *msg)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	struct spi_device *s = msg->spi;
+	u32 valus, rs = 0;
+
+	valus = readl(pspim->m_base + SP7021_SPI_STATUS_REG);
+	valus |= SP7021_FD_SW_RST;
+	writel(valus, pspim->m_base + SP7021_SPI_STATUS_REG);
+	rs |= SP7021_FD_SEL;
+	if (s->mode & SPI_CPOL)
+		rs |= SP7021_CPOL_FD;
+
+	if (s->mode & SPI_LSB_FIRST)
+		rs |= SP7021_LSB_SEL;
+
+	if (s->mode & SPI_CS_HIGH)
+		rs |= SP7021_CS_POR;
+
+	if (s->mode & SPI_CPHA)
+		rs |=  SP7021_CPHA_R;
+	else
+		rs |=  SP7021_CPHA_W;
+
+	rs |=  FIELD_PREP(SP7021_TX_UNIT, 0) | FIELD_PREP(SP7021_RX_UNIT, 0);
+	pspim->xfer_conf = rs;
+	if (pspim->xfer_conf & SP7021_CPOL_FD)
+		writel(pspim->xfer_conf, pspim->m_base + SP7021_SPI_CONFIG_REG);
+
+	return 0;
+}
+
+static void sp7021_spi_setup_clk(struct spi_controller *ctlr, struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	u32 clk_rate, clk_sel, div;
+
+	clk_rate = clk_get_rate(pspim->spi_clk);
+	div = clk_rate / xfer->speed_hz;
+	if (div < 2)
+		div = 2;
+	clk_sel = (div / 2) - 1;
+	pspim->xfer_conf &= SP7021_CLK_MASK;
+	pspim->xfer_conf |= FIELD_PREP(SP7021_CLK_MASK, clk_sel);
+	writel(pspim->xfer_conf, pspim->m_base + SP7021_SPI_CONFIG_REG);
+}
+
+static int sp7021_spi_master_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
+				       struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	unsigned long timeout = msecs_to_jiffies(1000);
+	unsigned int xfer_cnt, xfer_len, last_len;
+	unsigned int i, len_temp;
+	u32 reg_temp;
+	int ret;
+
+	xfer_cnt = xfer->len / SP7021_SPI_DATA_SIZE;
+	last_len = xfer->len % SP7021_SPI_DATA_SIZE;
+
+	for (i = 0; i <= xfer_cnt; i++) {
+		mutex_lock(&pspim->buf_lock);
+		sp7021_prep_transfer(ctlr, spi);
+		sp7021_spi_setup_clk(ctlr, xfer);
+		reinit_completion(&pspim->isr_done);
+
+		if (i == xfer_cnt)
+			xfer_len = last_len;
+		else
+			xfer_len = SP7021_SPI_DATA_SIZE;
+
+		pspim->tx_buf = xfer->tx_buf + i * SP7021_SPI_DATA_SIZE;
+		pspim->rx_buf = xfer->rx_buf + i * SP7021_SPI_DATA_SIZE;
+
+		if (pspim->tx_cur_len < xfer_len) {
+			len_temp = min(pspim->data_unit, xfer_len);
+			sp7021_spi_master_wb(pspim, len_temp);
+		}
+		reg_temp = readl(pspim->m_base + SP7021_SPI_CONFIG_REG);
+		reg_temp &= ~SP7021_CLEAN_RW_BYTE;
+		reg_temp &= ~SP7021_CLEAN_FLUG_MASK;
+		reg_temp |= SP7021_FD_SEL | SP7021_FINISH_FLAG_MASK |
+			    SP7021_TX_EMP_FLAG_MASK | SP7021_RX_FULL_FLAG_MASK |
+			    FIELD_PREP(SP7021_TX_UNIT, 0) | FIELD_PREP(SP7021_RX_UNIT, 0);
+		writel(reg_temp, pspim->m_base + SP7021_SPI_CONFIG_REG);
+
+		reg_temp = FIELD_PREP(SP7021_SET_TX_LEN, xfer_len) |
+				      FIELD_PREP(SP7021_SET_XFER_LEN, xfer_len) |
+				      SP7021_SPI_START_FD;
+		writel(reg_temp, pspim->m_base + SP7021_SPI_STATUS_REG);
+
+		if (!wait_for_completion_interruptible_timeout(&pspim->isr_done, timeout)) {
+			dev_err(&spi->dev, "wait_for_completion err\n");
+			return -ETIMEDOUT;
+		}
+
+		reg_temp = readl(pspim->m_base + SP7021_SPI_STATUS_REG);
+		if (reg_temp & SP7021_FINISH_FLAG) {
+			writel(SP7021_FINISH_FLAG, pspim->m_base + SP7021_SPI_STATUS_REG);
+			writel(readl(pspim->m_base + SP7021_SPI_CONFIG_REG) &
+				SP7021_CLEAN_FLUG_MASK, pspim->m_base + SP7021_SPI_CONFIG_REG);
+		}
+
+		if (pspim->xfer_conf & SP7021_CPOL_FD)
+			writel(pspim->xfer_conf, pspim->m_base + SP7021_SPI_CONFIG_REG);
+
+		mutex_unlock(&pspim->buf_lock);
+		ret = 0;
+	}
+	return ret;
+}
+
+static int sp7021_spi_slave_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
+				       struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+	struct device *dev = pspim->dev;
+	int mode, ret = 0;
+
+	mode = SP7021_SPI_IDLE;
+	if (xfer->tx_buf && xfer->rx_buf) {
+		dev_dbg(&ctlr->dev, "%s() wrong command\n", __func__);
+		ret = -EINVAL;
+	} else if (xfer->tx_buf) {
+		xfer->tx_dma = dma_map_single(dev, (void *)xfer->tx_buf,
+					      xfer->len, DMA_TO_DEVICE);
+		if (dma_mapping_error(dev, xfer->tx_dma))
+			return -ENOMEM;
+		mode = SP7021_SLAVE_WRITE;
+	} else if (xfer->rx_buf) {
+		xfer->rx_dma = dma_map_single(dev, xfer->rx_buf, xfer->len,
+					      DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev, xfer->rx_dma))
+			return -ENOMEM;
+		mode = SP7021_SLAVE_READ;
+	}
+
+	switch (mode) {
+	case SP7021_SLAVE_WRITE:
+		ret = sp7021_spi_slave_tx(spi, xfer);
+		break;
+	case SP7021_SLAVE_READ:
+		ret = sp7021_spi_slave_rx(spi, xfer);
+		break;
+	default:
+		break;
+	}
+	if (xfer->tx_buf)
+		dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
+	if (xfer->rx_buf)
+		dma_unmap_single(dev, xfer->rx_dma, xfer->len, DMA_FROM_DEVICE);
+
+	spi_finalize_current_transfer(ctlr);
+	return ret;
+}
+
+static void sp7021_spi_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static void sp7021_spi_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int sp7021_spi_controller_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sp7021_spi_ctlr *pspim;
+	struct spi_controller *ctlr;
+	int mode, ret;
+
+	pdev->id = of_alias_get_id(pdev->dev.of_node, "sp_spi");
+
+	if (device_property_read_bool(dev, "spi-slave"))
+		mode = SP7021_SLAVE_MODE;
+	else
+		mode = SP7021_MASTER_MODE;
+
+	if (mode == SP7021_SLAVE_MODE)
+		ctlr = devm_spi_alloc_slave(dev, sizeof(*pspim));
+	else
+		ctlr = devm_spi_alloc_master(dev, sizeof(*pspim));
+	if (!ctlr)
+		return -ENOMEM;
+	device_set_node(&ctlr->dev, pdev->dev.fwnode);
+	ctlr->bus_num = pdev->id;
+	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+	ctlr->auto_runtime_pm = true;
+	ctlr->prepare_message = sp7021_spi_controller_prepare_message;
+	if (mode == SP7021_SLAVE_MODE) {
+		ctlr->transfer_one = sp7021_spi_slave_transfer_one;
+		ctlr->slave_abort = sp7021_spi_slave_abort;
+		ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;
+	} else {
+		ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
+		ctlr->min_speed_hz = 40000;
+		ctlr->max_speed_hz = 25000000;
+		ctlr->use_gpio_descriptors = true;
+		ctlr->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;
+		ctlr->transfer_one = sp7021_spi_master_transfer_one;
+	}
+	platform_set_drvdata(pdev, ctlr);
+	pspim = spi_controller_get_devdata(ctlr);
+	pspim->mode = mode;
+	pspim->ctlr = ctlr;
+	pspim->dev = dev;
+	spin_lock_init(&pspim->lock);
+	mutex_init(&pspim->buf_lock);
+	init_completion(&pspim->isr_done);
+	init_completion(&pspim->slave_isr);
+
+	pspim->m_base = devm_platform_ioremap_resource_byname(pdev, "master");
+	if (IS_ERR(pspim->m_base))
+		return dev_err_probe(dev, PTR_ERR(pspim->m_base), "m_base get fail\n");
+
+	pspim->s_base = devm_platform_ioremap_resource_byname(pdev, "slave");
+	if (IS_ERR(pspim->s_base))
+		return dev_err_probe(dev, PTR_ERR(pspim->s_base), "s_base get fail\n");
+
+	pspim->m_irq = platform_get_irq_byname(pdev, "master_risc");
+	if (pspim->m_irq < 0)
+		return pspim->m_irq;
+
+	pspim->s_irq = platform_get_irq_byname(pdev, "slave_risc");
+	if (pspim->s_irq < 0)
+		return pspim->s_irq;
+
+	ret = devm_request_irq(dev, pspim->m_irq, sp7021_spi_master_irq,
+			       IRQF_TRIGGER_RISING, pdev->name, pspim);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(dev, pspim->s_irq, sp7021_spi_slave_irq,
+			       IRQF_TRIGGER_RISING, pdev->name, pspim);
+	if (ret)
+		return ret;
+
+	pspim->spi_clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(pspim->spi_clk))
+		return dev_err_probe(dev, PTR_ERR(pspim->spi_clk), "clk get fail\n");
+
+	pspim->rstc = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(pspim->rstc))
+		return dev_err_probe(dev, PTR_ERR(pspim->rstc), "rst get fail\n");
+
+	ret = clk_prepare_enable(pspim->spi_clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable clk\n");
+
+	ret = devm_add_action_or_reset(dev, sp7021_spi_disable_unprepare, pspim->spi_clk);
+	if (ret)
+		return ret;
+
+	ret = reset_control_deassert(pspim->rstc);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to deassert reset\n");
+
+	ret = devm_add_action_or_reset(dev, sp7021_spi_reset_control_assert, pspim->rstc);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(dev);
+	ret = spi_register_controller(ctlr);
+	if (ret) {
+		pm_runtime_disable(dev);
+		return dev_err_probe(dev, ret, "spi_register_master fail\n");
+	}
+	return 0;
+}
+
+static int sp7021_spi_controller_remove(struct platform_device *pdev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
+
+	spi_unregister_controller(ctlr);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	return 0;
+}
+
+static int __maybe_unused sp7021_spi_controller_suspend(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	return reset_control_assert(pspim->rstc);
+}
+
+static int __maybe_unused sp7021_spi_controller_resume(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	reset_control_deassert(pspim->rstc);
+	return clk_prepare_enable(pspim->spi_clk);
+}
+
+static int sp7021_spi_runtime_suspend(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	return reset_control_assert(pspim->rstc);
+}
+
+static int sp7021_spi_runtime_resume(struct device *dev)
+{
+	struct spi_controller *ctlr = dev_get_drvdata(dev);
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	return reset_control_deassert(pspim->rstc);
+}
+
+static const struct dev_pm_ops sp7021_spi_pm_ops = {
+	SET_RUNTIME_PM_OPS(sp7021_spi_runtime_suspend,
+			   sp7021_spi_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(sp7021_spi_controller_suspend,
+				sp7021_spi_controller_resume)
+};
+
+static const struct of_device_id sp7021_spi_controller_ids[] = {
+	{ .compatible = "sunplus,sp7021-spi" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sp7021_spi_controller_ids);
+
+static struct platform_driver sp7021_spi_controller_driver = {
+	.probe = sp7021_spi_controller_probe,
+	.remove = sp7021_spi_controller_remove,
+	.driver = {
+		.name = "sunplus,sp7021-spi-controller",
+		.of_match_table = sp7021_spi_controller_ids,
+		.pm     = &sp7021_spi_pm_ops,
+	},
+};
+module_platform_driver(sp7021_spi_controller_driver);
+
+MODULE_AUTHOR("Li-hao Kuo <lhjeff911@gmail.com>");
+MODULE_DESCRIPTION("Sunplus SPI controller driver");
+MODULE_LICENSE("GPL");
-- 
2.7.4

Re: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Mark Brown]

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On Tue, Jan 18, 2022 at 04:42:38PM +0800, Li-hao Kuo wrote:

Looks mostly good - a couple of small nits below but nothing major.

> +static int sp7021_spi_master_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
> +				       struct spi_transfer *xfer)
> +{

> +	for (i = 0; i <= xfer_cnt; i++) {
> +		mutex_lock(&pspim->buf_lock);

This lock is redundant: it is only ever held in this function which is
guaranteed by the core to never be called twice concurrently.

> +	ret = devm_request_irq(dev, pspim->m_irq, sp7021_spi_master_irq,
> +			       IRQF_TRIGGER_RISING, pdev->name, pspim);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_request_irq(dev, pspim->s_irq, sp7021_spi_slave_irq,
> +			       IRQF_TRIGGER_RISING, pdev->name, pspim);
> +	if (ret)
> +		return ret;

Are you sure the driver is ready to handle interrupts without any of the
other resources?  Normally interrupts are one of the last things to be
requested.

[-- Attachment #2: signature.asc --]
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RE: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Lh Kuo 郭力豪]

Hi Mr. Mark Brown :

Thanks for your comment, I will modify it in next next submission

> 
> > +	for (i = 0; i <= xfer_cnt; i++) {
> > +		mutex_lock(&pspim->buf_lock);
> 
> This lock is redundant: it is only ever held in this function which is guaranteed by the core to never be
> called twice concurrently.

I will modify it in next next submission


> > +	ret = devm_request_irq(dev, pspim->m_irq, sp7021_spi_master_irq,
> > +			       IRQF_TRIGGER_RISING, pdev->name, pspim);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = devm_request_irq(dev, pspim->s_irq, sp7021_spi_slave_irq,
> > +			       IRQF_TRIGGER_RISING, pdev->name, pspim);
> > +	if (ret)
> > +		return ret;
> 
> Are you sure the driver is ready to handle interrupts without any of the other resources?  Normally
> interrupts are one of the last things to be requested.

I will modify it in next next submission

Re: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Andy Shevchenko]

On Tue, Jan 18, 2022 at 10:42 AM Li-hao Kuo <lhjeff911@gmail.com> wrote:
>
> Add spi driver for Sunplus SP7021.

...

> Changes in v6:

Thanks for update, my comments below.

...

> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +#include <linux/spi/spi.h>

...

> +       data_status = readl(pspim->s_base + SP7021_DATA_RDY_REG);
> +       writel(data_status | SP7021_SLAVE_CLR_INT, pspim->s_base + SP7021_DATA_RDY_REG);

Wouldn't be

       data_status = readl(pspim->s_base + SP7021_DATA_RDY_REG);
       data_status |= SP7021_SLAVE_CLR_INT;
       writel(data_status, pspim->s_base + SP7021_DATA_RDY_REG);

better to read? Same question to other places like this.

...

> +       writel(SP7021_SLAVE_DMA_EN | SP7021_SLAVE_DMA_RW | FIELD_PREP(SP7021_SLAVE_DMA_CMD, 3),
> +              pspim->s_base + SP7021_SLAVE_DMA_CTRL_REG);

Temporary variable?
var = ...

...

> +       writel(readl(pspim->s_base + SP7021_DATA_RDY_REG) | SP7021_SLAVE_DATA_RDY,
> +              pspim->s_base + SP7021_DATA_RDY_REG);

Ditto.

...

> +int sp7021_spi_slave_rx(struct spi_device *spi, struct spi_transfer *xfer)
> +{
> +       struct sp7021_spi_ctlr *pspim = spi_controller_get_devdata(spi->controller);

> +       int ret = 0;

Unused.

...

> +       writel(SP7021_SLAVE_DMA_EN | FIELD_PREP(SP7021_SLAVE_DMA_CMD, 3),
> +              pspim->s_base + SP7021_SLAVE_DMA_CTRL_REG);

Temporary variable?

...

> +static irqreturn_t sp7021_spi_master_irq(int irq, void *dev)
> +{
> +       struct sp7021_spi_ctlr *pspim = dev;
> +       unsigned int tx_cnt, total_len;
> +       unsigned int tx_len, rx_cnt;
> +       unsigned int fd_status;

> +       unsigned long flags;

Why do you need this?

> +       bool isrdone = false;
> +       u32 value;

> +       return IRQ_HANDLED;
> +}

...

> +       div = clk_rate / xfer->speed_hz;
> +       if (div < 2)
> +               div = 2;

div = max(2U, clk_rate / xfer->speed_hz); ?

...

> +static int sp7021_spi_master_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
> +                                      struct spi_transfer *xfer)
> +{
> +       struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
> +       unsigned long timeout = msecs_to_jiffies(1000);
> +       unsigned int xfer_cnt, xfer_len, last_len;
> +       unsigned int i, len_temp;
> +       u32 reg_temp;

> +       int ret;

Seems redundant.

> +       xfer_cnt = xfer->len / SP7021_SPI_DATA_SIZE;
> +       last_len = xfer->len % SP7021_SPI_DATA_SIZE;
> +
> +       for (i = 0; i <= xfer_cnt; i++) {
> +               mutex_lock(&pspim->buf_lock);
> +               sp7021_prep_transfer(ctlr, spi);
> +               sp7021_spi_setup_clk(ctlr, xfer);
> +               reinit_completion(&pspim->isr_done);

> +               if (i == xfer_cnt)
> +                       xfer_len = last_len;
> +               else
> +                       xfer_len = SP7021_SPI_DATA_SIZE;
> +
> +               pspim->tx_buf = xfer->tx_buf + i * SP7021_SPI_DATA_SIZE;
> +               pspim->rx_buf = xfer->rx_buf + i * SP7021_SPI_DATA_SIZE;
> +
> +               if (pspim->tx_cur_len < xfer_len) {
> +                       len_temp = min(pspim->data_unit, xfer_len);
> +                       sp7021_spi_master_wb(pspim, len_temp);
> +               }
> +               reg_temp = readl(pspim->m_base + SP7021_SPI_CONFIG_REG);
> +               reg_temp &= ~SP7021_CLEAN_RW_BYTE;
> +               reg_temp &= ~SP7021_CLEAN_FLUG_MASK;
> +               reg_temp |= SP7021_FD_SEL | SP7021_FINISH_FLAG_MASK |
> +                           SP7021_TX_EMP_FLAG_MASK | SP7021_RX_FULL_FLAG_MASK |
> +                           FIELD_PREP(SP7021_TX_UNIT, 0) | FIELD_PREP(SP7021_RX_UNIT, 0);
> +               writel(reg_temp, pspim->m_base + SP7021_SPI_CONFIG_REG);
> +
> +               reg_temp = FIELD_PREP(SP7021_SET_TX_LEN, xfer_len) |
> +                                     FIELD_PREP(SP7021_SET_XFER_LEN, xfer_len) |
> +                                     SP7021_SPI_START_FD;
> +               writel(reg_temp, pspim->m_base + SP7021_SPI_STATUS_REG);
> +
> +               if (!wait_for_completion_interruptible_timeout(&pspim->isr_done, timeout)) {
> +                       dev_err(&spi->dev, "wait_for_completion err\n");
> +                       return -ETIMEDOUT;
> +               }
> +
> +               reg_temp = readl(pspim->m_base + SP7021_SPI_STATUS_REG);
> +               if (reg_temp & SP7021_FINISH_FLAG) {
> +                       writel(SP7021_FINISH_FLAG, pspim->m_base + SP7021_SPI_STATUS_REG);
> +                       writel(readl(pspim->m_base + SP7021_SPI_CONFIG_REG) &
> +                               SP7021_CLEAN_FLUG_MASK, pspim->m_base + SP7021_SPI_CONFIG_REG);
> +               }
> +
> +               if (pspim->xfer_conf & SP7021_CPOL_FD)
> +                       writel(pspim->xfer_conf, pspim->m_base + SP7021_SPI_CONFIG_REG);
> +
> +               mutex_unlock(&pspim->buf_lock);
> +               ret = 0;
> +       }
> +       return ret;
> +}

...

> +static int sp7021_spi_slave_transfer_one(struct spi_controller *ctlr, struct spi_device *spi,
> +                                      struct spi_transfer *xfer)
> +{
> +       struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
> +       struct device *dev = pspim->dev;

> +       int mode, ret = 0;

ret assignment can be moved to the default case below, where it will
naturally fit.

> +       mode = SP7021_SPI_IDLE;

> +       if (xfer->tx_buf && xfer->rx_buf) {
> +               dev_dbg(&ctlr->dev, "%s() wrong command\n", __func__);
> +               ret = -EINVAL;

Do you need this check if you properly set the capabilities of the controller?
If still needed, why not return here?

> +       } else if (xfer->tx_buf) {
> +               xfer->tx_dma = dma_map_single(dev, (void *)xfer->tx_buf,
> +                                             xfer->len, DMA_TO_DEVICE);
> +               if (dma_mapping_error(dev, xfer->tx_dma))
> +                       return -ENOMEM;
> +               mode = SP7021_SLAVE_WRITE;
> +       } else if (xfer->rx_buf) {
> +               xfer->rx_dma = dma_map_single(dev, xfer->rx_buf, xfer->len,
> +                                             DMA_FROM_DEVICE);
> +               if (dma_mapping_error(dev, xfer->rx_dma))
> +                       return -ENOMEM;
> +               mode = SP7021_SLAVE_READ;
> +       }
> +
> +       switch (mode) {
> +       case SP7021_SLAVE_WRITE:
> +               ret = sp7021_spi_slave_tx(spi, xfer);
> +               break;
> +       case SP7021_SLAVE_READ:
> +               ret = sp7021_spi_slave_rx(spi, xfer);
> +               break;
> +       default:
> +               break;
> +       }
> +       if (xfer->tx_buf)
> +               dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
> +       if (xfer->rx_buf)
> +               dma_unmap_single(dev, xfer->rx_dma, xfer->len, DMA_FROM_DEVICE);

Why can't you use SPI core DMA mapping code?

> +       spi_finalize_current_transfer(ctlr);
> +       return ret;
> +}

...

> +       device_set_node(&ctlr->dev, pdev->dev.fwnode);

Use dev_fwnode() in the second argument.

-- 
With Best Regards,
Andy Shevchenko

RE: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Lh Kuo 郭力豪]

Hi Andy Shevchenko :

Thanks for your comment, I have some questions as below.

> > +       if (xfer->tx_buf)
> > +               dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
> > +       if (xfer->rx_buf)
> > +               dma_unmap_single(dev, xfer->rx_dma, xfer->len,
> > + DMA_FROM_DEVICE);
> 
> Why can't you use SPI core DMA mapping code?

I didn't find the SPI core DMA mapping code for single maping. 
The method currently used is the general DMA single-map code usage method.


> 
> > +       device_set_node(&ctlr->dev, pdev->dev.fwnode);
> 
> Use dev_fwnode() in the second argument.
>

You mean as below ?

device_set_node(&ctlr->dev, dev_fwnode(dev));

Best Regards,
Li-hao Kuo

Re: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Andy Shevchenko]

On Thu, Jan 20, 2022 at 11:22 AM Lh Kuo 郭力豪 <lh.Kuo@sunplus.com> wrote:

...

> > > +       if (xfer->tx_buf)
> > > +               dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
> > > +       if (xfer->rx_buf)
> > > +               dma_unmap_single(dev, xfer->rx_dma, xfer->len,
> > > + DMA_FROM_DEVICE);
> >
> > Why can't you use SPI core DMA mapping code?
>
> I didn't find the SPI core DMA mapping code for single maping.
> The method currently used is the general DMA single-map code usage method.

Why do you need single page mapping?
What's wrong with SG mapping that SPI core provides?

...

> > > +       device_set_node(&ctlr->dev, pdev->dev.fwnode);
> >
> > Use dev_fwnode() in the second argument.
>
> You mean as below ?
>
> device_set_node(&ctlr->dev, dev_fwnode(dev));

Yes.

-- 
With Best Regards,
Andy Shevchenko

RE: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Lh Kuo 郭力豪]

> > > > +       if (xfer->tx_buf)
> > > > +               dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
> > > > +       if (xfer->rx_buf)
> > > > +               dma_unmap_single(dev, xfer->rx_dma, xfer->len,
> > > > + DMA_FROM_DEVICE);
> > >
> > > Why can't you use SPI core DMA mapping code?
> >
> > I didn't find the SPI core DMA mapping code for single maping.
> > The method currently used is the general DMA single-map code usage method.
> 
> Why do you need single page mapping?
> What's wrong with SG mapping that SPI core provides?

SP7021 SPI slave dma only supports single dma in one trigger. 
It is not suitable for using SG mapping.
If the length of the transfer is larger than the length of the SG-mapping, 
Slave-mode will get error in the transfer.

Re: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Andy Shevchenko]

On Fri, Jan 21, 2022 at 8:54 AM Lh Kuo 郭力豪 <lh.Kuo@sunplus.com> wrote:
>
> > > > > +       if (xfer->tx_buf)
> > > > > +               dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
> > > > > +       if (xfer->rx_buf)
> > > > > +               dma_unmap_single(dev, xfer->rx_dma, xfer->len,
> > > > > + DMA_FROM_DEVICE);
> > > >
> > > > Why can't you use SPI core DMA mapping code?
> > >
> > > I didn't find the SPI core DMA mapping code for single maping.
> > > The method currently used is the general DMA single-map code usage method.
> >
> > Why do you need single page mapping?
> > What's wrong with SG mapping that SPI core provides?
>
> SP7021 SPI slave dma only supports single dma in one trigger.
> It is not suitable for using SG mapping.
> If the length of the transfer is larger than the length of the SG-mapping,
> Slave-mode will get error in the transfer.

Same story for SPI DesignWare on Intel Medfield, where no SG transfers
are supported by hardware. Nevertheless, the DMA driver takes care of
this and on each interrupt recharges a channel to continue. Why can't
the same be implemented here?


-- 
With Best Regards,
Andy Shevchenko

RE: [PATCH v6 1/2] spi: Add spi driver for Sunplus SP7021

[Lh Kuo 郭力豪]

> > > > > > +       if (xfer->tx_buf)
> > > > > > +               dma_unmap_single(dev, xfer->tx_dma, xfer->len, DMA_TO_DEVICE);
> > > > > > +       if (xfer->rx_buf)
> > > > > > +               dma_unmap_single(dev, xfer->rx_dma, xfer->len,
> > > > > > + DMA_FROM_DEVICE);
> > > > >
> > > > > Why can't you use SPI core DMA mapping code?
> > > >
> > > > I didn't find the SPI core DMA mapping code for single maping.
> > > > The method currently used is the general DMA single-map code usage method.
> > >
> > > Why do you need single page mapping?
> > > What's wrong with SG mapping that SPI core provides?
> >
> > SP7021 SPI slave dma only supports single dma in one trigger.
> > It is not suitable for using SG mapping.
> > If the length of the transfer is larger than the length of the
> > SG-mapping, Slave-mode will get error in the transfer.
> 
> Same story for SPI DesignWare on Intel Medfield, where no SG transfers are supported by hardware.
> Nevertheless, the DMA driver takes care of this and on each interrupt recharges a channel to continue.
> Why can't the same be implemented here?
> 
> 
I think it should work in master. spi master must actively send clk and date to slave device.
And yes, in the "master" mode it can handle SG-DMA on each interrupt.
But if working in "slave" mode, the master will not know the state of the slave. Slaves work on interrupt and recharge channels.
When master send clk and date in the same time. It may lose data and errors occur

[PATCH v6 2/2] dt-bindings:spi: Add Sunplus SP7021 schema

[Li-hao Kuo]

Add bindings for Sunplus SP7021 spi driver

Signed-off-by: Li-hao Kuo <lhjeff911@gmail.com>
---
Changes in v6:
 - Change the interrupt-names 
   mas_risc to master_risc
 - Addressed comments from Mr. Andy Shevchenko
   Change the function name: mas is master and sla is slave.
   Add temporary varilable (as suggested by Mr. Andy Shevchenko)
   Modify clk setting
   Modify the master-slave detection of the probe function.(as suggested by Mr. Andy Shevchenko)
   Modify the return value of the probe function.(as suggested by Mr. Andy Shevchenko)
   Change GPL version(as suggested by Mr. Andy Shevchenko)

 .../bindings/spi/spi-sunplus-sp7021.yaml           | 81 ++++++++++++++++++++++
 MAINTAINERS                                        |  1 +
 2 files changed, 82 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml

diff --git a/Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml b/Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml
new file mode 100644
index 0000000..24382cd
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright (C) Sunplus Co., Ltd. 2021
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/spi-sunplus-sp7021.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sunplus sp7021 SPI controller
+
+allOf:
+  - $ref: "spi-controller.yaml"
+
+maintainers:
+  - Li-hao Kuo <lhjeff911@gmail.com>
+
+properties:
+  compatible:
+    enum:
+      - sunplus,sp7021-spi
+
+  reg:
+    items:
+      - the SPI master registers
+      - the SPI slave registers
+
+  reg-names:
+    items:
+      - const: master
+      - const: slave
+
+  interrupt-names:
+    items:
+      - const: dma_w
+      - const: master_risc
+      - const: slave_risc
+
+  interrupts:
+    minItems: 3
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - interrupts
+  - interrupt-names
+  - clocks
+  - clocks-names
+  - resets
+  - pinctrl-names
+  - pinctrl-0
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/sp-sp7021.h>
+    #include <dt-bindings/reset/sp-sp7021.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    spi@9C002D80 {
+        compatible = "sunplus,sp7021-spi";
+        reg = <0x9C002D80 0x80>, <0x9C002E00 0x80>;
+        reg-names = "master", "slave";
+        interrupt-parent = <&intc>;
+        interrupt-names = "dma_w",
+                          "master_risc",
+                          "slave_risc";
+        interrupts = <144 IRQ_TYPE_LEVEL_HIGH>,
+                     <146 IRQ_TYPE_LEVEL_HIGH>,
+                     <145 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clkc SPI_COMBO_0>;
+        resets = <&rstc RST_SPI_COMBO_0>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&pins_spi0>;
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index a07da20..2e14650 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18497,6 +18497,7 @@ SUNPLUS SPI CONTROLLER INTERFACE DRIVER
 M:	Li-hao Kuo <lhjeff911@gmail.com>
 L:	linux-spi@vger.kernel.org
 S:	Maintained
+F:	Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml
 F:	drivers/spi/spi-sunplus-sp7021.c
 
 SUPERH
-- 
2.7.4

Re: [PATCH v6 2/2] dt-bindings:spi: Add Sunplus SP7021 schema

[Rob Herring]

On Tue, Jan 18, 2022 at 2:42 AM Li-hao Kuo <lhjeff911@gmail.com> wrote:
>
> Add bindings for Sunplus SP7021 spi driver
>
> Signed-off-by: Li-hao Kuo <lhjeff911@gmail.com>
> ---
> Changes in v6:
>  - Change the interrupt-names
>    mas_risc to master_risc
>  - Addressed comments from Mr. Andy Shevchenko
>    Change the function name: mas is master and sla is slave.
>    Add temporary varilable (as suggested by Mr. Andy Shevchenko)
>    Modify clk setting
>    Modify the master-slave detection of the probe function.(as suggested by Mr. Andy Shevchenko)
>    Modify the return value of the probe function.(as suggested by Mr. Andy Shevchenko)
>    Change GPL version(as suggested by Mr. Andy Shevchenko)
>
>  .../bindings/spi/spi-sunplus-sp7021.yaml           | 81 ++++++++++++++++++++++
>  MAINTAINERS                                        |  1 +
>  2 files changed, 82 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml

This is now failing in linux-next, please fix:

/builds/robherring/linux-dt/Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml:
properties:reg:items: 'anyOf' conditional failed, one must be fixed:
 ['the SPI master registers', 'the SPI slave registers'] is not of
type 'object', 'boolean'
 'the SPI master registers' is not of type 'object', 'boolean'
 'the SPI slave registers' is not of type 'object', 'boolean'
 from schema $id: http://json-schema.org/draft-07/schema#
/builds/robherring/linux-dt/Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml:
ignoring, error in schema: properties: reg: items
Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.example.dts:19:18:
fatal error: dt-bindings/clock/sp-sp7021.h: No such file or directory
 19 | #include <dt-bindings/clock/sp-sp7021.h>
    | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make[1]: *** [scripts/Makefile.lib:390:
Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.example.dt.yaml]
Error 1

Re: [PATCH v6 0/2] Add spi control driver for Sunplus SP7021 SoC

[Mark Brown]

On Tue, 18 Jan 2022 16:42:37 +0800, Li-hao Kuo wrote:
> This is a patch series for SPI driver for Sunplus SP7021 SoC.
> 
> Sunplus SP7021 is an ARM Cortex A7 (4 cores) based SoC. It integrates
> many peripherals (ex: UART, I2C, SPI, SDIO, eMMC, USB, SD card and
> etc.) into a single chip. It is designed for industrial control.
> 
> Refer to:
> https://sunplus-tibbo.atlassian.net/wiki/spaces/doc/overview
> https://tibbo.com/store/plus1.html
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/2] spi: Add spi driver for Sunplus SP7021
      commit: f62ca4e2a863033d9b3b5a00a0d897557c9da6c5
[2/2] dt-bindings:spi: Add Sunplus SP7021 schema
      (no commit info)

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark