Applied "spi: spi-mem: add stm32 qspi controller" to the spi tree

[Mark Brown <broonie@xxxxxxxxxx>]

The patch

   spi: spi-mem: add stm32 qspi controller

has been applied to the spi tree at

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

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

>From 95f36f17841ee13605a923ff7e6f2ccf95e8626f Mon Sep 17 00:00:00 2001
From: Ludovic Barre <ludovic.barre@xxxxxx>
Date: Fri, 5 Oct 2018 09:43:03 +0200
Subject: [PATCH] spi: spi-mem: add stm32 qspi controller

The qspi controller is a specialized communication interface
targeting single, dual or quad SPI Flash memories (NOR/NAND).

It can operate in any of the following modes:
-indirect mode: all the operations are performed using the quadspi
 registers
-read memory-mapped mode: the external Flash memory is mapped to the
 microcontroller address space and is seen by the system as if it was
 an internal memory

tested on:
-NOR: mx66l51235l
-NAND: MT29F2G01ABAGD

Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/spi/Kconfig          |   9 +
 drivers/spi/Makefile         |   1 +
 drivers/spi/spi-stm32-qspi.c | 512 +++++++++++++++++++++++++++++++++++
 3 files changed, 522 insertions(+)
 create mode 100644 drivers/spi/spi-stm32-qspi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7feab4eb9857..71851d00f47d 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -647,6 +647,15 @@ config SPI_STM32
 	  is not available, the driver automatically falls back to
 	  PIO mode.
 
+config SPI_STM32_QSPI
+	tristate "STMicroelectronics STM32 QUAD SPI controller"
+	depends on ARCH_STM32 || COMPILE_TEST
+	depends on OF
+	help
+	  This enables support for the Quad SPI controller in master mode.
+	  This driver does not support generic SPI. The implementation only
+	  supports spi-mem interface.
+
 config SPI_ST_SSC4
 	tristate "STMicroelectronics SPI SSC-based driver"
 	depends on ARCH_STI || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 7e7df53fc73a..df04dfbe7d70 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -94,6 +94,7 @@ obj-$(CONFIG_SPI_SLAVE_MT27XX)          += spi-slave-mt27xx.o
 obj-$(CONFIG_SPI_SPRD)			+= spi-sprd.o
 obj-$(CONFIG_SPI_SPRD_ADI)		+= spi-sprd-adi.o
 obj-$(CONFIG_SPI_STM32) 		+= spi-stm32.o
+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
diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c
new file mode 100644
index 000000000000..3b2a9a6b990d
--- /dev/null
+++ b/drivers/spi/spi-stm32-qspi.c
@@ -0,0 +1,512 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
+ * Author: Ludovic Barre <ludovic.barre@xxxxxx> for STMicroelectronics.
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/sizes.h>
+#include <linux/spi/spi-mem.h>
+
+#define QSPI_CR			0x00
+#define CR_EN			BIT(0)
+#define CR_ABORT		BIT(1)
+#define CR_DMAEN		BIT(2)
+#define CR_TCEN			BIT(3)
+#define CR_SSHIFT		BIT(4)
+#define CR_DFM			BIT(6)
+#define CR_FSEL			BIT(7)
+#define CR_FTHRES_MASK		GENMASK(12, 8)
+#define CR_TEIE			BIT(16)
+#define CR_TCIE			BIT(17)
+#define CR_FTIE			BIT(18)
+#define CR_SMIE			BIT(19)
+#define CR_TOIE			BIT(20)
+#define CR_PRESC_MASK		GENMASK(31, 24)
+
+#define QSPI_DCR		0x04
+#define DCR_FSIZE_MASK		GENMASK(20, 16)
+
+#define QSPI_SR			0x08
+#define SR_TEF			BIT(0)
+#define SR_TCF			BIT(1)
+#define SR_FTF			BIT(2)
+#define SR_SMF			BIT(3)
+#define SR_TOF			BIT(4)
+#define SR_BUSY			BIT(5)
+#define SR_FLEVEL_MASK		GENMASK(13, 8)
+
+#define QSPI_FCR		0x0c
+#define FCR_CTEF		BIT(0)
+#define FCR_CTCF		BIT(1)
+
+#define QSPI_DLR		0x10
+
+#define QSPI_CCR		0x14
+#define CCR_INST_MASK		GENMASK(7, 0)
+#define CCR_IMODE_MASK		GENMASK(9, 8)
+#define CCR_ADMODE_MASK		GENMASK(11, 10)
+#define CCR_ADSIZE_MASK		GENMASK(13, 12)
+#define CCR_DCYC_MASK		GENMASK(22, 18)
+#define CCR_DMODE_MASK		GENMASK(25, 24)
+#define CCR_FMODE_MASK		GENMASK(27, 26)
+#define CCR_FMODE_INDW		(0U << 26)
+#define CCR_FMODE_INDR		(1U << 26)
+#define CCR_FMODE_APM		(2U << 26)
+#define CCR_FMODE_MM		(3U << 26)
+#define CCR_BUSWIDTH_0		0x0
+#define CCR_BUSWIDTH_1		0x1
+#define CCR_BUSWIDTH_2		0x2
+#define CCR_BUSWIDTH_4		0x3
+
+#define QSPI_AR			0x18
+#define QSPI_ABR		0x1c
+#define QSPI_DR			0x20
+#define QSPI_PSMKR		0x24
+#define QSPI_PSMAR		0x28
+#define QSPI_PIR		0x2c
+#define QSPI_LPTR		0x30
+#define LPTR_DFT_TIMEOUT	0x10
+
+#define STM32_QSPI_MAX_MMAP_SZ	SZ_256M
+#define STM32_QSPI_MAX_NORCHIP	2
+
+#define STM32_FIFO_TIMEOUT_US 30000
+#define STM32_BUSY_TIMEOUT_US 100000
+#define STM32_ABT_TIMEOUT_US 100000
+
+struct stm32_qspi_flash {
+	struct stm32_qspi *qspi;
+	u32 cs;
+	u32 presc;
+};
+
+struct stm32_qspi {
+	struct device *dev;
+	void __iomem *io_base;
+	void __iomem *mm_base;
+	resource_size_t mm_size;
+	struct clk *clk;
+	u32 clk_rate;
+	struct stm32_qspi_flash flash[STM32_QSPI_MAX_NORCHIP];
+	struct completion data_completion;
+	u32 fmode;
+
+	/*
+	 * to protect device configuration, could be different between
+	 * 2 flash access (bk1, bk2)
+	 */
+	struct mutex lock;
+};
+
+static irqreturn_t stm32_qspi_irq(int irq, void *dev_id)
+{
+	struct stm32_qspi *qspi = (struct stm32_qspi *)dev_id;
+	u32 cr, sr;
+
+	sr = readl_relaxed(qspi->io_base + QSPI_SR);
+
+	if (sr & (SR_TEF | SR_TCF)) {
+		/* disable irq */
+		cr = readl_relaxed(qspi->io_base + QSPI_CR);
+		cr &= ~CR_TCIE & ~CR_TEIE;
+		writel_relaxed(cr, qspi->io_base + QSPI_CR);
+		complete(&qspi->data_completion);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
+{
+	*val = readb_relaxed(addr);
+}
+
+static void stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
+{
+	writeb_relaxed(*val, addr);
+}
+
+static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
+			      const struct spi_mem_op *op)
+{
+	void (*tx_fifo)(u8 *val, void __iomem *addr);
+	u32 len = op->data.nbytes, sr;
+	u8 *buf;
+	int ret;
+
+	if (op->data.dir == SPI_MEM_DATA_IN) {
+		tx_fifo = stm32_qspi_read_fifo;
+		buf = op->data.buf.in;
+
+	} else {
+		tx_fifo = stm32_qspi_write_fifo;
+		buf = (u8 *)op->data.buf.out;
+	}
+
+	while (len--) {
+		ret = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR,
+							sr, (sr & SR_FTF), 1,
+							STM32_FIFO_TIMEOUT_US);
+		if (ret) {
+			dev_err(qspi->dev, "fifo timeout (len:%d stat:%#x)\n",
+				len, sr);
+			return ret;
+		}
+		tx_fifo(buf++, qspi->io_base + QSPI_DR);
+	}
+
+	return 0;
+}
+
+static int stm32_qspi_tx_mm(struct stm32_qspi *qspi,
+			    const struct spi_mem_op *op)
+{
+	memcpy_fromio(op->data.buf.in, qspi->mm_base + op->addr.val,
+		      op->data.nbytes);
+	return 0;
+}
+
+static int stm32_qspi_tx(struct stm32_qspi *qspi, const struct spi_mem_op *op)
+{
+	if (!op->data.nbytes)
+		return 0;
+
+	if (qspi->fmode == CCR_FMODE_MM)
+		return stm32_qspi_tx_mm(qspi, op);
+
+	return stm32_qspi_tx_poll(qspi, op);
+}
+
+static int stm32_qspi_wait_nobusy(struct stm32_qspi *qspi)
+{
+	u32 sr;
+
+	return readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR, sr,
+						 !(sr & SR_BUSY), 1,
+						 STM32_BUSY_TIMEOUT_US);
+}
+
+static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi,
+			       const struct spi_mem_op *op)
+{
+	u32 cr, sr;
+	int err = 0;
+
+	if (!op->data.nbytes)
+		return stm32_qspi_wait_nobusy(qspi);
+
+	if (readl_relaxed(qspi->io_base + QSPI_SR) & SR_TCF)
+		goto out;
+
+	reinit_completion(&qspi->data_completion);
+	cr = readl_relaxed(qspi->io_base + QSPI_CR);
+	writel_relaxed(cr | CR_TCIE | CR_TEIE, qspi->io_base + QSPI_CR);
+
+	if (!wait_for_completion_interruptible_timeout(&qspi->data_completion,
+						msecs_to_jiffies(1000))) {
+		err = -ETIMEDOUT;
+	} else {
+		sr = readl_relaxed(qspi->io_base + QSPI_SR);
+		if (sr & SR_TEF)
+			err = -EIO;
+	}
+
+out:
+	/* clear flags */
+	writel_relaxed(FCR_CTCF | FCR_CTEF, qspi->io_base + QSPI_FCR);
+
+	return err;
+}
+
+static int stm32_qspi_get_mode(struct stm32_qspi *qspi, u8 buswidth)
+{
+	if (buswidth == 4)
+		return CCR_BUSWIDTH_4;
+
+	return buswidth;
+}
+
+static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
+	struct stm32_qspi_flash *flash = &qspi->flash[mem->spi->chip_select];
+	u32 ccr, cr, addr_max;
+	int timeout, err = 0;
+
+	dev_dbg(qspi->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n",
+		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
+		op->dummy.buswidth, op->data.buswidth,
+		op->addr.val, op->data.nbytes);
+
+	err = stm32_qspi_wait_nobusy(qspi);
+	if (err)
+		goto abort;
+
+	addr_max = op->addr.val + op->data.nbytes + 1;
+
+	if (op->data.dir == SPI_MEM_DATA_IN) {
+		if (addr_max < qspi->mm_size &&
+		    op->addr.buswidth)
+			qspi->fmode = CCR_FMODE_MM;
+		else
+			qspi->fmode = CCR_FMODE_INDR;
+	} else {
+		qspi->fmode = CCR_FMODE_INDW;
+	}
+
+	cr = readl_relaxed(qspi->io_base + QSPI_CR);
+	cr &= ~CR_PRESC_MASK & ~CR_FSEL;
+	cr |= FIELD_PREP(CR_PRESC_MASK, flash->presc);
+	cr |= FIELD_PREP(CR_FSEL, flash->cs);
+	writel_relaxed(cr, qspi->io_base + QSPI_CR);
+
+	if (op->data.nbytes)
+		writel_relaxed(op->data.nbytes - 1,
+			       qspi->io_base + QSPI_DLR);
+	else
+		qspi->fmode = CCR_FMODE_INDW;
+
+	ccr = qspi->fmode;
+	ccr |= FIELD_PREP(CCR_INST_MASK, op->cmd.opcode);
+	ccr |= FIELD_PREP(CCR_IMODE_MASK,
+			  stm32_qspi_get_mode(qspi, op->cmd.buswidth));
+
+	if (op->addr.nbytes) {
+		ccr |= FIELD_PREP(CCR_ADMODE_MASK,
+				  stm32_qspi_get_mode(qspi, op->addr.buswidth));
+		ccr |= FIELD_PREP(CCR_ADSIZE_MASK, op->addr.nbytes - 1);
+	}
+
+	if (op->dummy.buswidth && op->dummy.nbytes)
+		ccr |= FIELD_PREP(CCR_DCYC_MASK,
+				  op->dummy.nbytes * 8 / op->dummy.buswidth);
+
+	if (op->data.nbytes) {
+		ccr |= FIELD_PREP(CCR_DMODE_MASK,
+				  stm32_qspi_get_mode(qspi, op->data.buswidth));
+	}
+
+	writel_relaxed(ccr, qspi->io_base + QSPI_CCR);
+
+	if (op->addr.nbytes && qspi->fmode != CCR_FMODE_MM)
+		writel_relaxed(op->addr.val, qspi->io_base + QSPI_AR);
+
+	err = stm32_qspi_tx(qspi, op);
+
+	/*
+	 * Abort in:
+	 * -error case
+	 * -read memory map: prefetching must be stopped if we read the last
+	 *  byte of device (device size - fifo size). like device size is not
+	 *  knows, the prefetching is always stop.
+	 */
+	if (err || qspi->fmode == CCR_FMODE_MM)
+		goto abort;
+
+	/* wait end of tx in indirect mode */
+	err = stm32_qspi_wait_cmd(qspi, op);
+	if (err)
+		goto abort;
+
+	return 0;
+
+abort:
+	cr = readl_relaxed(qspi->io_base + QSPI_CR) | CR_ABORT;
+	writel_relaxed(cr, qspi->io_base + QSPI_CR);
+
+	/* wait clear of abort bit by hw */
+	timeout = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_CR,
+						    cr, !(cr & CR_ABORT), 1,
+						    STM32_ABT_TIMEOUT_US);
+
+	writel_relaxed(FCR_CTCF, qspi->io_base + QSPI_FCR);
+
+	if (err || timeout)
+		dev_err(qspi->dev, "%s err:%d abort timeout:%d\n",
+			__func__, err, timeout);
+
+	return err;
+}
+
+static int stm32_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
+	int ret;
+
+	mutex_lock(&qspi->lock);
+	ret = stm32_qspi_send(mem, op);
+	mutex_unlock(&qspi->lock);
+
+	return ret;
+}
+
+static int stm32_qspi_setup(struct spi_device *spi)
+{
+	struct spi_controller *ctrl = spi->master;
+	struct stm32_qspi *qspi = spi_controller_get_devdata(ctrl);
+	struct stm32_qspi_flash *flash;
+	u32 cr, presc;
+
+	if (ctrl->busy)
+		return -EBUSY;
+
+	if (!spi->max_speed_hz)
+		return -EINVAL;
+
+	presc = DIV_ROUND_UP(qspi->clk_rate, spi->max_speed_hz) - 1;
+
+	flash = &qspi->flash[spi->chip_select];
+	flash->qspi = qspi;
+	flash->cs = spi->chip_select;
+	flash->presc = presc;
+
+	mutex_lock(&qspi->lock);
+	writel_relaxed(LPTR_DFT_TIMEOUT, qspi->io_base + QSPI_LPTR);
+	cr = FIELD_PREP(CR_FTHRES_MASK, 3) | CR_TCEN | CR_SSHIFT | CR_EN;
+	writel_relaxed(cr, qspi->io_base + QSPI_CR);
+
+	/* set dcr fsize to max address */
+	writel_relaxed(DCR_FSIZE_MASK, qspi->io_base + QSPI_DCR);
+	mutex_unlock(&qspi->lock);
+
+	return 0;
+}
+
+/*
+ * no special host constraint, so use default spi_mem_default_supports_op
+ * to check supported mode.
+ */
+static const struct spi_controller_mem_ops stm32_qspi_mem_ops = {
+	.exec_op = stm32_qspi_exec_op,
+};
+
+static void stm32_qspi_release(struct stm32_qspi *qspi)
+{
+	/* disable qspi */
+	writel_relaxed(0, qspi->io_base + QSPI_CR);
+	mutex_destroy(&qspi->lock);
+	clk_disable_unprepare(qspi->clk);
+}
+
+static int stm32_qspi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct spi_controller *ctrl;
+	struct reset_control *rstc;
+	struct stm32_qspi *qspi;
+	struct resource *res;
+	int ret, irq;
+
+	ctrl = spi_alloc_master(dev, sizeof(*qspi));
+	if (!ctrl)
+		return -ENOMEM;
+
+	qspi = spi_controller_get_devdata(ctrl);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi");
+	qspi->io_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(qspi->io_base))
+		return PTR_ERR(qspi->io_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mm");
+	qspi->mm_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(qspi->mm_base))
+		return PTR_ERR(qspi->mm_base);
+
+	qspi->mm_size = resource_size(res);
+	if (qspi->mm_size > STM32_QSPI_MAX_MMAP_SZ)
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	ret = devm_request_irq(dev, irq, stm32_qspi_irq, 0,
+			       dev_name(dev), qspi);
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		return ret;
+	}
+
+	init_completion(&qspi->data_completion);
+
+	qspi->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(qspi->clk))
+		return PTR_ERR(qspi->clk);
+
+	qspi->clk_rate = clk_get_rate(qspi->clk);
+	if (!qspi->clk_rate)
+		return -EINVAL;
+
+	ret = clk_prepare_enable(qspi->clk);
+	if (ret) {
+		dev_err(dev, "can not enable the clock\n");
+		return ret;
+	}
+
+	rstc = devm_reset_control_get_exclusive(dev, NULL);
+	if (!IS_ERR(rstc)) {
+		reset_control_assert(rstc);
+		udelay(2);
+		reset_control_deassert(rstc);
+	}
+
+	qspi->dev = dev;
+	platform_set_drvdata(pdev, qspi);
+	mutex_init(&qspi->lock);
+
+	ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD
+		| SPI_TX_DUAL | SPI_TX_QUAD;
+	ctrl->setup = stm32_qspi_setup;
+	ctrl->bus_num = -1;
+	ctrl->mem_ops = &stm32_qspi_mem_ops;
+	ctrl->num_chipselect = STM32_QSPI_MAX_NORCHIP;
+	ctrl->dev.of_node = dev->of_node;
+
+	ret = devm_spi_register_master(dev, ctrl);
+	if (ret)
+		goto err_spi_register;
+
+	return 0;
+
+err_spi_register:
+	stm32_qspi_release(qspi);
+
+	return ret;
+}
+
+static int stm32_qspi_remove(struct platform_device *pdev)
+{
+	struct stm32_qspi *qspi = platform_get_drvdata(pdev);
+
+	stm32_qspi_release(qspi);
+	return 0;
+}
+
+static const struct of_device_id stm32_qspi_match[] = {
+	{.compatible = "st,stm32f469-qspi"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, stm32_qspi_match);
+
+static struct platform_driver stm32_qspi_driver = {
+	.probe	= stm32_qspi_probe,
+	.remove	= stm32_qspi_remove,
+	.driver	= {
+		.name = "stm32-qspi",
+		.of_match_table = stm32_qspi_match,
+	},
+};
+module_platform_driver(stm32_qspi_driver);
+
+MODULE_AUTHOR("Ludovic Barre <ludovic.barre@xxxxxx>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 quad spi driver");
+MODULE_LICENSE("GPL v2");
-- 
2.19.0.rc2