RE: [Linux-stm32] [PATCH 2/2] spi: spi-mem: add stm32 qspi controller
From: Loic PALLARDY
Date: Fri Oct 05 2018 - 03:56:24 EST
> -----Original Message-----
> From: Linux-stm32 <linux-stm32-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
> On Behalf Of Ludovic Barre
> Sent: Friday, October 05, 2018 9:43 AM
> To: Mark Brown <broonie@xxxxxxxxxx>; Marek Vasut
> <marek.vasut@xxxxxxxxx>; Boris Brezillon <boris.brezillon@xxxxxxxxxxx>;
> Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> spi@xxxxxxxxxxxxxxx; Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>;
> linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx
> Subject: [Linux-stm32] [PATCH 2/2] spi: spi-mem: add stm32 qspi controller
>
> From: Ludovic Barre <ludovic.barre@xxxxxx>
>
> 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>
> ---
> 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 92bf64d..ea1e651 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -622,6 +622,15 @@ 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 a09681b..2f27b81c3 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -91,6 +91,7 @@ obj-$(CONFIG_SPI_SH_SCI) += spi-sh-
> sci.o
> obj-$(CONFIG_SPI_SIRF) += spi-sirf.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 0000000..3b2a9a6
> --- /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)
> + */
[LPA] In English, sentence starts with capital letter and finishes with a point.
> + 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;
> +
[LPA] remove blank line
> + } 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");
> --
> 2.7.4
>
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