linux-stable/drivers/spi/spi-stm32-qspi.c
Ludovic Barre c530cd1d9d
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@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-10-19 13:32:56 +01:00

512 lines
12 KiB
C

// 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");