[PATCH v5 0/2] Add SPI control driver for Sunplus SP7021 SoC

[PATCH v5 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
  devicetree: bindings SPI Add bindings doc for Sunplus SP7021

 .../bindings/spi/spi-sunplus-sp7021.yaml           |  81 +++
 MAINTAINERS                                        |   7 +
 drivers/spi/Kconfig                                |  11 +
 drivers/spi/Makefile                               |   1 +
 drivers/spi/spi-sunplus_sp7021.c                   | 603 +++++++++++++++++++++
 5 files changed, 703 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 v5 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 v5:
 - Addressed comments from Mr. Mark Brown 
 - Addressed comments from Mr. Andy Shevchenko

 MAINTAINERS                      |   6 +
 drivers/spi/Kconfig              |  11 +
 drivers/spi/Makefile             |   1 +
 drivers/spi/spi-sunplus_sp7021.c | 603 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 621 insertions(+)
 create mode 100644 drivers/spi/spi-sunplus_sp7021.c

diff --git a/MAINTAINERS b/MAINTAINERS
index dd36acc..1732a9e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18243,6 +18243,12 @@ 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 596705d..f248fb7 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..b4607a0
--- /dev/null
+++ b/drivers/spi/spi-sunplus_sp7021.c
@@ -0,0 +1,603 @@
+// 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_SLV_DMA_CTRL_REG   0x0048
+#define SP7021_SLV_DMA_LENGTH_REG 0x004c
+#define SP7021_SLV_DMA_ADDR_REG   0x004c
+
+#define SP7021_SLA_DATA_RDY       BIT(0)
+#define SP7021_SLA_SW_RST         BIT(1)
+#define SP7021_SLA_DMA_W_INT      BIT(8)
+#define SP7021_SLA_CLR_INT        BIT(8)
+#define SP7021_SLA_DMA_EN         BIT(0)
+#define SP7021_SLA_DMA_RW         BIT(6)
+#define SP7021_SLA_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_INT_BYPASS         BIT(3)
+#define SP7021_CLR_MAS_INT        BIT(6)
+#define SP7021_CLR_MAS_W_INT      BIT(7)
+
+#define SP7021_SPI_DATA_SIZE      (255)
+#define SP7021_FIFO_DATA_LEN      (16)
+
+enum SP_SPI_MODE {
+	SP7021_SLA_READ = 0,
+	SP7021_SLA_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 sla_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_sla_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_SLA_CLR_INT, pspim->s_base + SP7021_DATA_RDY_REG);
+	complete(&pspim->sla_isr);
+	return IRQ_HANDLED;
+}
+
+static int sp7021_spi_sla_abort(struct spi_controller *ctlr)
+{
+	struct sp7021_spi_ctlr *pspim = spi_master_get_devdata(ctlr);
+
+	complete(&pspim->sla_isr);
+	complete(&pspim->isr_done);
+	return 0;
+}
+
+int sp7021_spi_sla_tx(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct sp7021_spi_ctlr *pspim = spi_controller_get_devdata(spi->controller);
+
+	reinit_completion(&pspim->sla_isr);
+	writel(SP7021_SLA_DMA_EN | SP7021_SLA_DMA_RW | FIELD_PREP(SP7021_SLA_DMA_CMD, 3),
+	       pspim->s_base + SP7021_SLV_DMA_CTRL_REG);
+	writel(xfer->len, pspim->s_base + SP7021_SLV_DMA_LENGTH_REG);
+	writel(xfer->tx_dma, pspim->s_base + SP7021_SLV_DMA_ADDR_REG);
+	writel(readl(pspim->s_base + SP7021_DATA_RDY_REG) | SP7021_SLA_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_sla_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_SLA_DMA_EN | FIELD_PREP(SP7021_SLA_DMA_CMD, 3),
+	       pspim->s_base + SP7021_SLV_DMA_CTRL_REG);
+	writel(xfer->len, pspim->s_base + SP7021_SLV_DMA_LENGTH_REG);
+	writel(xfer->rx_dma, pspim->s_base + SP7021_SLV_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_SLA_SW_RST, pspim->s_base + SP7021_SLV_DMA_CTRL_REG);
+	return ret;
+}
+
+void sp7021_spi_mas_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_mas_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_mas_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;
+
+	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_mas_rb(pspim, rx_cnt);
+	if (tx_cnt > 0)
+		sp7021_spi_mas_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_mas_rb(pspim, rx_cnt);
+		}
+		writel(readl(pspim->m_base + SP7021_INT_BUSY_REG)
+			| SP7021_CLR_MAS_INT, 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 rs = 0;
+
+	writel(readl(pspim->m_base + SP7021_SPI_STATUS_REG) | SP7021_FD_SW_RST,
+	       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);
+	unsigned int 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 |= ((clk_sel & 0xffff) << 16);
+	writel(pspim->xfer_conf, pspim->m_base + SP7021_SPI_CONFIG_REG);
+}
+
+static int sp7021_spi_mas_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_mas_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);
+		}
+
+		ret = 0;
+
+		if (pspim->xfer_conf & SP7021_CPOL_FD)
+			writel(pspim->xfer_conf, pspim->m_base + SP7021_SPI_CONFIG_REG);
+
+		mutex_unlock(&pspim->buf_lock);
+	}
+	return ret;
+}
+
+static int sp7021_spi_sla_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 (spi_controller_is_slave(ctlr)) {
+		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_SLA_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_SLA_READ;
+		}
+
+		switch (mode) {
+		case SP7021_SLA_WRITE:
+			sp7021_spi_sla_tx(spi, xfer);
+			break;
+		case SP7021_SLA_READ:
+			sp7021_spi_sla_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;
+
+	mode = SP7021_MASTER_MODE;
+	pdev->id = of_alias_get_id(pdev->dev.of_node, "sp_spi");
+
+	if (of_property_read_bool(pdev->dev.of_node, "spi-slave"))
+		mode = SP7021_SLAVE_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_sla_transfer_one;
+		ctlr->slave_abort = sp7021_spi_sla_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_mas_transfer_one;
+	}
+	platform_set_drvdata(pdev, ctlr);
+	pspim = spi_controller_get_devdata(ctlr);
+	pspim->ctlr = ctlr;
+	pspim->dev = dev;
+	spin_lock_init(&pspim->lock);
+	mutex_init(&pspim->buf_lock);
+	init_completion(&pspim->isr_done);
+	init_completion(&pspim->sla_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, "mas_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_mas_irq,
+			       IRQF_TRIGGER_RISING, pdev->name, pspim);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(dev, pspim->s_irq, sp7021_spi_sla_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 ret;
+}
+
+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 v2");
-- 
2.7.4

[PATCH v5 2/2] devicetree: bindings SPI Add bindings doc for Sunplus SP7021

[Li-hao Kuo]

Add devicetree bindings SPI Add bindings doc for Sunplus SP7021

Reviewed by Mr. Rob Herring <robh+dt@kernel.org>
Signed-off-by: Li-hao Kuo <lhjeff911@gmail.com>
---
Changes in v5:
 - no change.
 - Reviewed by Mr. Rob Herring <robh+dt@kernel.org>

 .../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..096bfae
--- /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: mas_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",
+                          "mas_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 1732a9e..2f487be 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18247,6 +18247,7 @@ 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 v5 1/2] SPI: Add SPI driver for Sunplus SP7021

[Andy Shevchenko]

On Mon, Jan 10, 2022 at 8:47 AM Li-hao Kuo <lhjeff911@gmail.com> wrote:
>
> Add SPI driver for Sunplus SP7021.

In the subject line use small letters in the prefix. Check with `git
log -- drivers/spi` how people do.

Common comment: Consider to use spi_controller_*() APIs over
spi_master_*() ones. Also your SLA/MAS (and sla/mas) are a bit
confusing: spell them in full and master --> controller or ctrl, slave
--> peripheral or alike.

> Signed-off-by: Li-hao Kuo <lhjeff911@gmail.com>
> ---
> Changes in v5:
>  - Addressed comments from Mr. Mark Brown
>  - Addressed comments from Mr. Andy Shevchenko

You need to elaborate what exactly you addressed.

...

> +               writel(readl(pspim->m_base + SP7021_INT_BUSY_REG)
> +                       | SP7021_CLR_MAS_INT, pspim->m_base + SP7021_INT_BUSY_REG);

It's better to read with temporary variable being used:

             value = readl(pspim->m_base + SP7021_INT_BUSY_REG);
             value |= SP7021_CLR_MAS_INT;
             writel(value, pspim->m_base + SP7021_INT_BUSY_REG);

...

> +       writel(readl(pspim->m_base + SP7021_SPI_STATUS_REG) | SP7021_FD_SW_RST,
> +              pspim->m_base + SP7021_SPI_STATUS_REG);

Ditto. And for all other similar cases.

...

> +       pspim->xfer_conf |= ((clk_sel & 0xffff) << 16);

Is xfer_conf bigger than 32-bit? If not, why do you need the ' & 0xffff' part?

...

> +               ret = 0;

Is it necessary to do this under the lock?

> +               if (pspim->xfer_conf & SP7021_CPOL_FD)
> +                       writel(pspim->xfer_conf, pspim->m_base + SP7021_SPI_CONFIG_REG);
> +
> +               mutex_unlock(&pspim->buf_lock);

...

> +       if (spi_controller_is_slave(ctlr)) {

Factor out this body to a function, it will increase readability.

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

...

> +       mode = SP7021_MASTER_MODE;

This...

> +       pdev->id = of_alias_get_id(pdev->dev.of_node, "sp_spi");

> +       if (of_property_read_bool(pdev->dev.of_node, "spi-slave"))
> +               mode = SP7021_SLAVE_MODE;

...belongs to this condition, so do not interleave them.

On top of that you may use device property API:

    if (device_property_read_bool(&pdev->dev, "spi-slave"))
        mode = SP7021_SLAVE_MODE;
    else
        mode = SP7021_MASTER_MODE;

...

> +       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 ret;

return 0;

...

> +MODULE_LICENSE("GPL v2");

"GPL", the one you used is legacy.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5 1/2] SPI: Add SPI driver for Sunplus SP7021

[kernel test robot]

Hi Li-hao,

I love your patch! Yet something to improve:

[auto build test ERROR on broonie-spi/for-next]
[also build test ERROR on pza/reset/next robh/for-next linus/master v5.16]
[cannot apply to next-20220110]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Li-hao-Kuo/Add-SPI-control-driver-for-Sunplus-SP7021-SoC/20220110-144745
base:   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20220110/202201101911.hSqY5DkA-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/53da1eda2d6e7a04e09dcb37a029ec3b384b7afb
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Li-hao-Kuo/Add-SPI-control-driver-for-Sunplus-SP7021-SoC/20220110-144745
        git checkout 53da1eda2d6e7a04e09dcb37a029ec3b384b7afb
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=alpha SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> make[3]: *** No rule to make target 'drivers/spi/spi-sunplus-sp7021.o', needed by 'drivers/spi/built-in.a'.
   make[3]: Target '__build' not remade because of errors.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

Re: [PATCH v5 2/2] devicetree: bindings SPI Add bindings doc for Sunplus SP7021

[Rob Herring]

On Mon, Jan 10, 2022 at 02:47:22PM +0800, Li-hao Kuo wrote:
> Add devicetree bindings SPI Add bindings doc for Sunplus SP7021
> 
> Reviewed by Mr. Rob Herring <robh+dt@kernel.org>

Tag is wrong in multiple ways. It must be exactly what I gave:

Acked-by: Rob Herring <robh@kernel.org>

> Signed-off-by: Li-hao Kuo <lhjeff911@gmail.com>
> ---
> Changes in v5:
>  - no change.
>  - Reviewed by Mr. Rob Herring <robh+dt@kernel.org>
> 
>  .../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..096bfae
> --- /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: mas_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",
> +                          "mas_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 1732a9e..2f487be 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18247,6 +18247,7 @@ 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 v5 1/2] SPI: Add SPI driver for Sunplus SP7021

[Lh Kuo 郭力豪]

> > +               writel(readl(pspim->m_base + SP7021_INT_BUSY_REG)
> > +                       | SP7021_CLR_MAS_INT, pspim->m_base +
> > + SP7021_INT_BUSY_REG);
> 
> It's better to read with temporary variable being used:
> 
>              value = readl(pspim->m_base + SP7021_INT_BUSY_REG);
>              value |= SP7021_CLR_MAS_INT;
>              writel(value, pspim->m_base + SP7021_INT_BUSY_REG);

I will add it in next next submission

> > +       pspim->xfer_conf |= ((clk_sel & 0xffff) << 16);
> 
> Is xfer_conf bigger than 32-bit? If not, why do you need the ' & 0xffff' part?
> 
> ...

I will add it in next next submission

> > +               mode = SP7021_SLAVE_MODE;
> 
> ...belongs to this condition, so do not interleave them.
> 
> On top of that you may use device property API:
> 
>     if (device_property_read_bool(&pdev->dev, "spi-slave"))
>         mode = SP7021_SLAVE_MODE;
>     else
>         mode = SP7021_MASTER_MODE;


I will add it in next next submission


> > +               return dev_err_probe(dev, ret, "spi_register_master fail\n");
> > +       }
> > +
> > +       return ret;
> 
> return 0;
> 
> ...
> 
> > +MODULE_LICENSE("GPL v2");
> 
> "GPL", the one you used is legacy.
>


I will add it in next next submission