linux/drivers/spi/spi-ti-qspi.c

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/*
* TI QSPI driver
*
* Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
* Author: Sourav Poddar <sourav.poddar@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GPLv2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/omap-dma.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
struct ti_qspi_regs {
u32 clkctrl;
};
struct ti_qspi {
/* list synchronization */
struct mutex list_lock;
struct spi_master *master;
void __iomem *base;
void __iomem *mmap_base;
struct regmap *ctrl_base;
unsigned int ctrl_reg;
struct clk *fclk;
struct device *dev;
struct ti_qspi_regs ctx_reg;
u32 spi_max_frequency;
u32 cmd;
u32 dc;
bool mmap_enabled;
};
#define QSPI_PID (0x0)
#define QSPI_SYSCONFIG (0x10)
#define QSPI_SPI_CLOCK_CNTRL_REG (0x40)
#define QSPI_SPI_DC_REG (0x44)
#define QSPI_SPI_CMD_REG (0x48)
#define QSPI_SPI_STATUS_REG (0x4c)
#define QSPI_SPI_DATA_REG (0x50)
#define QSPI_SPI_SETUP_REG(n) ((0x54 + 4 * n))
#define QSPI_SPI_SWITCH_REG (0x64)
#define QSPI_SPI_DATA_REG_1 (0x68)
#define QSPI_SPI_DATA_REG_2 (0x6c)
#define QSPI_SPI_DATA_REG_3 (0x70)
#define QSPI_COMPLETION_TIMEOUT msecs_to_jiffies(2000)
#define QSPI_FCLK 192000000
/* Clock Control */
#define QSPI_CLK_EN (1 << 31)
#define QSPI_CLK_DIV_MAX 0xffff
/* Command */
#define QSPI_EN_CS(n) (n << 28)
#define QSPI_WLEN(n) ((n - 1) << 19)
#define QSPI_3_PIN (1 << 18)
#define QSPI_RD_SNGL (1 << 16)
#define QSPI_WR_SNGL (2 << 16)
#define QSPI_RD_DUAL (3 << 16)
#define QSPI_RD_QUAD (7 << 16)
#define QSPI_INVAL (4 << 16)
#define QSPI_FLEN(n) ((n - 1) << 0)
#define QSPI_WLEN_MAX_BITS 128
#define QSPI_WLEN_MAX_BYTES 16
#define QSPI_WLEN_MASK QSPI_WLEN(QSPI_WLEN_MAX_BITS)
/* STATUS REGISTER */
#define BUSY 0x01
#define WC 0x02
/* Device Control */
#define QSPI_DD(m, n) (m << (3 + n * 8))
#define QSPI_CKPHA(n) (1 << (2 + n * 8))
#define QSPI_CSPOL(n) (1 << (1 + n * 8))
#define QSPI_CKPOL(n) (1 << (n * 8))
#define QSPI_FRAME 4096
#define QSPI_AUTOSUSPEND_TIMEOUT 2000
#define MEM_CS_EN(n) ((n + 1) << 8)
#define MEM_CS_MASK (7 << 8)
#define MM_SWITCH 0x1
#define QSPI_SETUP_RD_NORMAL (0x0 << 12)
#define QSPI_SETUP_RD_DUAL (0x1 << 12)
#define QSPI_SETUP_RD_QUAD (0x3 << 12)
#define QSPI_SETUP_ADDR_SHIFT 8
#define QSPI_SETUP_DUMMY_SHIFT 10
static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
unsigned long reg)
{
return readl(qspi->base + reg);
}
static inline void ti_qspi_write(struct ti_qspi *qspi,
unsigned long val, unsigned long reg)
{
writel(val, qspi->base + reg);
}
static int ti_qspi_setup(struct spi_device *spi)
{
struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
int clk_div = 0, ret;
u32 clk_ctrl_reg, clk_rate, clk_mask;
if (spi->master->busy) {
dev_dbg(qspi->dev, "master busy doing other transfers\n");
return -EBUSY;
}
if (!qspi->spi_max_frequency) {
dev_err(qspi->dev, "spi max frequency not defined\n");
return -EINVAL;
}
clk_rate = clk_get_rate(qspi->fclk);
clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;
if (clk_div < 0) {
dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
return -EINVAL;
}
if (clk_div > QSPI_CLK_DIV_MAX) {
dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
return -EINVAL;
}
dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
qspi->spi_max_frequency, clk_div);
ret = pm_runtime_get_sync(qspi->dev);
if (ret < 0) {
dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
return ret;
}
clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);
clk_ctrl_reg &= ~QSPI_CLK_EN;
/* disable SCLK */
ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);
/* enable SCLK */
clk_mask = QSPI_CLK_EN | clk_div;
ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
ctx_reg->clkctrl = clk_mask;
pm_runtime_mark_last_busy(qspi->dev);
ret = pm_runtime_put_autosuspend(qspi->dev);
if (ret < 0) {
dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
return ret;
}
return 0;
}
static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
{
struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
}
static inline u32 qspi_is_busy(struct ti_qspi *qspi)
{
u32 stat;
unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
while ((stat & BUSY) && time_after(timeout, jiffies)) {
cpu_relax();
stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
}
WARN(stat & BUSY, "qspi busy\n");
return stat & BUSY;
}
static inline int ti_qspi_poll_wc(struct ti_qspi *qspi)
{
u32 stat;
unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
do {
stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
if (stat & WC)
return 0;
cpu_relax();
} while (time_after(timeout, jiffies));
stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
if (stat & WC)
return 0;
return -ETIMEDOUT;
}
static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t,
int count)
{
int wlen, xfer_len;
unsigned int cmd;
const u8 *txbuf;
u32 data;
txbuf = t->tx_buf;
cmd = qspi->cmd | QSPI_WR_SNGL;
wlen = t->bits_per_word >> 3; /* in bytes */
xfer_len = wlen;
while (count) {
if (qspi_is_busy(qspi))
return -EBUSY;
switch (wlen) {
case 1:
dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
cmd, qspi->dc, *txbuf);
if (count >= QSPI_WLEN_MAX_BYTES) {
u32 *txp = (u32 *)txbuf;
data = cpu_to_be32(*txp++);
writel(data, qspi->base +
QSPI_SPI_DATA_REG_3);
data = cpu_to_be32(*txp++);
writel(data, qspi->base +
QSPI_SPI_DATA_REG_2);
data = cpu_to_be32(*txp++);
writel(data, qspi->base +
QSPI_SPI_DATA_REG_1);
data = cpu_to_be32(*txp++);
writel(data, qspi->base +
QSPI_SPI_DATA_REG);
xfer_len = QSPI_WLEN_MAX_BYTES;
cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
} else {
writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
cmd = qspi->cmd | QSPI_WR_SNGL;
xfer_len = wlen;
cmd |= QSPI_WLEN(wlen);
}
break;
case 2:
dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
cmd, qspi->dc, *txbuf);
writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
break;
case 4:
dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
cmd, qspi->dc, *txbuf);
writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
break;
}
ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
if (ti_qspi_poll_wc(qspi)) {
dev_err(qspi->dev, "write timed out\n");
return -ETIMEDOUT;
}
txbuf += xfer_len;
count -= xfer_len;
}
return 0;
}
static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t,
int count)
{
int wlen;
unsigned int cmd;
u8 *rxbuf;
rxbuf = t->rx_buf;
cmd = qspi->cmd;
switch (t->rx_nbits) {
case SPI_NBITS_DUAL:
cmd |= QSPI_RD_DUAL;
break;
case SPI_NBITS_QUAD:
cmd |= QSPI_RD_QUAD;
break;
default:
cmd |= QSPI_RD_SNGL;
break;
}
wlen = t->bits_per_word >> 3; /* in bytes */
while (count) {
dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
if (qspi_is_busy(qspi))
return -EBUSY;
ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
if (ti_qspi_poll_wc(qspi)) {
dev_err(qspi->dev, "read timed out\n");
return -ETIMEDOUT;
}
switch (wlen) {
case 1:
*rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
break;
case 2:
*((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
break;
case 4:
*((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
break;
}
rxbuf += wlen;
count -= wlen;
}
return 0;
}
static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t,
int count)
{
int ret;
if (t->tx_buf) {
ret = qspi_write_msg(qspi, t, count);
if (ret) {
dev_dbg(qspi->dev, "Error while writing\n");
return ret;
}
}
if (t->rx_buf) {
ret = qspi_read_msg(qspi, t, count);
if (ret) {
dev_dbg(qspi->dev, "Error while reading\n");
return ret;
}
}
return 0;
}
static void ti_qspi_enable_memory_map(struct spi_device *spi)
{
struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
ti_qspi_write(qspi, MM_SWITCH, QSPI_SPI_SWITCH_REG);
if (qspi->ctrl_base) {
regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
MEM_CS_EN(spi->chip_select),
MEM_CS_MASK);
}
qspi->mmap_enabled = true;
}
static void ti_qspi_disable_memory_map(struct spi_device *spi)
{
struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
ti_qspi_write(qspi, 0, QSPI_SPI_SWITCH_REG);
if (qspi->ctrl_base)
regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
0, MEM_CS_MASK);
qspi->mmap_enabled = false;
}
static void ti_qspi_setup_mmap_read(struct spi_device *spi,
struct spi_flash_read_message *msg)
{
struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
u32 memval = msg->read_opcode;
switch (msg->data_nbits) {
case SPI_NBITS_QUAD:
memval |= QSPI_SETUP_RD_QUAD;
break;
case SPI_NBITS_DUAL:
memval |= QSPI_SETUP_RD_DUAL;
break;
default:
memval |= QSPI_SETUP_RD_NORMAL;
break;
}
memval |= ((msg->addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
msg->dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
ti_qspi_write(qspi, memval,
QSPI_SPI_SETUP_REG(spi->chip_select));
}
static int ti_qspi_spi_flash_read(struct spi_device *spi,
struct spi_flash_read_message *msg)
{
struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
int ret = 0;
mutex_lock(&qspi->list_lock);
if (!qspi->mmap_enabled)
ti_qspi_enable_memory_map(spi);
ti_qspi_setup_mmap_read(spi, msg);
memcpy_fromio(msg->buf, qspi->mmap_base + msg->from, msg->len);
msg->retlen = msg->len;
mutex_unlock(&qspi->list_lock);
return ret;
}
static int ti_qspi_start_transfer_one(struct spi_master *master,
struct spi_message *m)
{
struct ti_qspi *qspi = spi_master_get_devdata(master);
struct spi_device *spi = m->spi;
struct spi_transfer *t;
int status = 0, ret;
unsigned int frame_len_words, transfer_len_words;
int wlen;
/* setup device control reg */
qspi->dc = 0;
if (spi->mode & SPI_CPHA)
qspi->dc |= QSPI_CKPHA(spi->chip_select);
if (spi->mode & SPI_CPOL)
qspi->dc |= QSPI_CKPOL(spi->chip_select);
if (spi->mode & SPI_CS_HIGH)
qspi->dc |= QSPI_CSPOL(spi->chip_select);
frame_len_words = 0;
list_for_each_entry(t, &m->transfers, transfer_list)
frame_len_words += t->len / (t->bits_per_word >> 3);
frame_len_words = min_t(unsigned int, frame_len_words, QSPI_FRAME);
/* setup command reg */
qspi->cmd = 0;
qspi->cmd |= QSPI_EN_CS(spi->chip_select);
qspi->cmd |= QSPI_FLEN(frame_len_words);
ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);
mutex_lock(&qspi->list_lock);
if (qspi->mmap_enabled)
ti_qspi_disable_memory_map(spi);
list_for_each_entry(t, &m->transfers, transfer_list) {
qspi->cmd = ((qspi->cmd & ~QSPI_WLEN_MASK) |
QSPI_WLEN(t->bits_per_word));
wlen = t->bits_per_word >> 3;
transfer_len_words = min(t->len / wlen, frame_len_words);
ret = qspi_transfer_msg(qspi, t, transfer_len_words * wlen);
if (ret) {
dev_dbg(qspi->dev, "transfer message failed\n");
mutex_unlock(&qspi->list_lock);
return -EINVAL;
}
m->actual_length += transfer_len_words * wlen;
frame_len_words -= transfer_len_words;
if (frame_len_words == 0)
break;
}
mutex_unlock(&qspi->list_lock);
spi: ti-qspi: Fix data corruption seen on r/w stress test Writing invalid command to QSPI_SPI_CMD_REG will terminate current transfer and de-assert the chip select. This has to be done before calling spi_finalize_current_message(). Because spi_finalize_current_message() will mark the end of current message transfer and schedule the next transfer. If the chipselect is not de-asserted before calling spi_finalize_current_message() then the next transfer will overlap with the previous transfer leading to data corruption. __spi_pump_message() can be called either from kthread worker context or directly from the calling process's context. It is possible that these two calls can race against each other. But race is serialized by checking whether master->cur_msg == NULL (pointer to msg being handled by transfer_one() at present). The master->cur_msg is set to NULL when spi_finalize_current_message() is called on that message, which means calling spi_finalize_current_message() allows __spi_sync() to pump next message in calling process context. Now if spi-ti-qspi calls spi_finalize_current_message() before we terminate transfer at hardware side, if __spi_pump_message() is called from process context then the successive transactions can overlap. Fix this by moving writing invalid command to QSPI_SPI_CMD_REG to before calling spi_finalize_current_message() call. Cc: stable@vger.kernel.org # v3.12+ Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-12 07:52:02 +00:00
ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);
m->status = status;
spi_finalize_current_message(master);
return status;
}
static int ti_qspi_runtime_resume(struct device *dev)
{
struct ti_qspi *qspi;
qspi = dev_get_drvdata(dev);
ti_qspi_restore_ctx(qspi);
return 0;
}
static const struct of_device_id ti_qspi_match[] = {
{.compatible = "ti,dra7xxx-qspi" },
{.compatible = "ti,am4372-qspi" },
{},
};
MODULE_DEVICE_TABLE(of, ti_qspi_match);
static int ti_qspi_probe(struct platform_device *pdev)
{
struct ti_qspi *qspi;
struct spi_master *master;
struct resource *r, *res_mmap;
struct device_node *np = pdev->dev.of_node;
u32 max_freq;
int ret = 0, num_cs, irq;
master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
if (!master)
return -ENOMEM;
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD;
master->flags = SPI_MASTER_HALF_DUPLEX;
master->setup = ti_qspi_setup;
master->auto_runtime_pm = true;
master->transfer_one_message = ti_qspi_start_transfer_one;
master->dev.of_node = pdev->dev.of_node;
master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
SPI_BPW_MASK(8);
if (!of_property_read_u32(np, "num-cs", &num_cs))
master->num_chipselect = num_cs;
qspi = spi_master_get_devdata(master);
qspi->master = master;
qspi->dev = &pdev->dev;
platform_set_drvdata(pdev, qspi);
r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
if (r == NULL) {
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
dev_err(&pdev->dev, "missing platform data\n");
return -ENODEV;
}
}
res_mmap = platform_get_resource_byname(pdev,
IORESOURCE_MEM, "qspi_mmap");
if (res_mmap == NULL) {
res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (res_mmap == NULL) {
dev_err(&pdev->dev,
"memory mapped resource not required\n");
}
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "no irq resource?\n");
return irq;
}
mutex_init(&qspi->list_lock);
qspi->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(qspi->base)) {
ret = PTR_ERR(qspi->base);
goto free_master;
}
if (res_mmap) {
qspi->mmap_base = devm_ioremap_resource(&pdev->dev,
res_mmap);
master->spi_flash_read = ti_qspi_spi_flash_read;
if (IS_ERR(qspi->mmap_base)) {
dev_err(&pdev->dev,
"falling back to PIO mode\n");
master->spi_flash_read = NULL;
}
}
qspi->mmap_enabled = false;
if (of_property_read_bool(np, "syscon-chipselects")) {
qspi->ctrl_base =
syscon_regmap_lookup_by_phandle(np,
"syscon-chipselects");
if (IS_ERR(qspi->ctrl_base))
return PTR_ERR(qspi->ctrl_base);
ret = of_property_read_u32_index(np,
"syscon-chipselects",
1, &qspi->ctrl_reg);
if (ret) {
dev_err(&pdev->dev,
"couldn't get ctrl_mod reg index\n");
return ret;
}
}
qspi->fclk = devm_clk_get(&pdev->dev, "fck");
if (IS_ERR(qspi->fclk)) {
ret = PTR_ERR(qspi->fclk);
dev_err(&pdev->dev, "could not get clk: %d\n", ret);
}
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
pm_runtime_enable(&pdev->dev);
if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
qspi->spi_max_frequency = max_freq;
ret = devm_spi_register_master(&pdev->dev, master);
if (ret)
goto free_master;
return 0;
free_master:
spi_master_put(master);
return ret;
}
static int ti_qspi_remove(struct platform_device *pdev)
{
struct ti_qspi *qspi = platform_get_drvdata(pdev);
int rc;
rc = spi_master_suspend(qspi->master);
if (rc)
return rc;
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return 0;
}
static const struct dev_pm_ops ti_qspi_pm_ops = {
.runtime_resume = ti_qspi_runtime_resume,
};
static struct platform_driver ti_qspi_driver = {
.probe = ti_qspi_probe,
.remove = ti_qspi_remove,
.driver = {
.name = "ti-qspi",
.pm = &ti_qspi_pm_ops,
.of_match_table = ti_qspi_match,
}
};
module_platform_driver(ti_qspi_driver);
MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TI QSPI controller driver");
MODULE_ALIAS("platform:ti-qspi");