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Subject[PATCH 2/2] spi: spi-mem: add stm32 qspi controller
Date
From: Ludovic Barre <ludovic.barre@st.com>

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@st.com>
---
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@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");
--
2.7.4
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