Unverified Commit c530cd1d authored by Ludovic Barre's avatar Ludovic Barre Committed by Mark Brown
Browse files

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: default avatarLudovic Barre <ludovic.barre@st.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent c3e6845e

drivers/spi/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -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

drivers/spi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/spi/spi-stm32-qspi.c

0 → 100644
+512 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) STMicroelectronics 2018 - All Rights Reserved

 * Author: Ludovic Barre <ludovic.barre@st.com> 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@st.com>");

MODULE_DESCRIPTION("STMicroelectronics STM32 quad spi driver");

MODULE_LICENSE("GPL v2");

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