diff options
Diffstat (limited to 'drivers/spi/spi-stm32-qspi.c')
| -rw-r--r-- | drivers/spi/spi-stm32-qspi.c | 512 |
1 files changed, 512 insertions, 0 deletions
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@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"); |