linux/drivers/spi/spi-tegra20-sflash.c
Amit Kumar Mahapatra via Alsa-devel 9e264f3f85
spi: Replace all spi->chip_select and spi->cs_gpiod references with function call
Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de> # Rockchip drivers
Reviewed-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org> # Aspeed driver
Reviewed-by: Dhruva Gole <d-gole@ti.com> # SPI Cadence QSPI
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> # spi-stm32-qspi
Acked-by: William Zhang <william.zhang@broadcom.com> # bcm63xx-hsspi driver
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> # DW SSI part
Link: https://lore.kernel.org/r/167847070432.26.15076794204368669839@mailman-core.alsa-project.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-03-11 12:34:01 +00:00

607 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* SPI driver for Nvidia's Tegra20 Serial Flash Controller.
*
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
*
* Author: Laxman Dewangan <ldewangan@nvidia.com>
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/reset.h>
#include <linux/spi/spi.h>
#define SPI_COMMAND 0x000
#define SPI_GO BIT(30)
#define SPI_M_S BIT(28)
#define SPI_ACTIVE_SCLK_MASK (0x3 << 26)
#define SPI_ACTIVE_SCLK_DRIVE_LOW (0 << 26)
#define SPI_ACTIVE_SCLK_DRIVE_HIGH (1 << 26)
#define SPI_ACTIVE_SCLK_PULL_LOW (2 << 26)
#define SPI_ACTIVE_SCLK_PULL_HIGH (3 << 26)
#define SPI_CK_SDA_FALLING (1 << 21)
#define SPI_CK_SDA_RISING (0 << 21)
#define SPI_CK_SDA_MASK (1 << 21)
#define SPI_ACTIVE_SDA (0x3 << 18)
#define SPI_ACTIVE_SDA_DRIVE_LOW (0 << 18)
#define SPI_ACTIVE_SDA_DRIVE_HIGH (1 << 18)
#define SPI_ACTIVE_SDA_PULL_LOW (2 << 18)
#define SPI_ACTIVE_SDA_PULL_HIGH (3 << 18)
#define SPI_CS_POL_INVERT BIT(16)
#define SPI_TX_EN BIT(15)
#define SPI_RX_EN BIT(14)
#define SPI_CS_VAL_HIGH BIT(13)
#define SPI_CS_VAL_LOW 0x0
#define SPI_CS_SW BIT(12)
#define SPI_CS_HW 0x0
#define SPI_CS_DELAY_MASK (7 << 9)
#define SPI_CS3_EN BIT(8)
#define SPI_CS2_EN BIT(7)
#define SPI_CS1_EN BIT(6)
#define SPI_CS0_EN BIT(5)
#define SPI_CS_MASK (SPI_CS3_EN | SPI_CS2_EN | \
SPI_CS1_EN | SPI_CS0_EN)
#define SPI_BIT_LENGTH(x) (((x) & 0x1f) << 0)
#define SPI_MODES (SPI_ACTIVE_SCLK_MASK | SPI_CK_SDA_MASK)
#define SPI_STATUS 0x004
#define SPI_BSY BIT(31)
#define SPI_RDY BIT(30)
#define SPI_TXF_FLUSH BIT(29)
#define SPI_RXF_FLUSH BIT(28)
#define SPI_RX_UNF BIT(27)
#define SPI_TX_OVF BIT(26)
#define SPI_RXF_EMPTY BIT(25)
#define SPI_RXF_FULL BIT(24)
#define SPI_TXF_EMPTY BIT(23)
#define SPI_TXF_FULL BIT(22)
#define SPI_BLK_CNT(count) (((count) & 0xffff) + 1)
#define SPI_FIFO_ERROR (SPI_RX_UNF | SPI_TX_OVF)
#define SPI_FIFO_EMPTY (SPI_TX_EMPTY | SPI_RX_EMPTY)
#define SPI_RX_CMP 0x8
#define SPI_DMA_CTL 0x0C
#define SPI_DMA_EN BIT(31)
#define SPI_IE_RXC BIT(27)
#define SPI_IE_TXC BIT(26)
#define SPI_PACKED BIT(20)
#define SPI_RX_TRIG_MASK (0x3 << 18)
#define SPI_RX_TRIG_1W (0x0 << 18)
#define SPI_RX_TRIG_4W (0x1 << 18)
#define SPI_TX_TRIG_MASK (0x3 << 16)
#define SPI_TX_TRIG_1W (0x0 << 16)
#define SPI_TX_TRIG_4W (0x1 << 16)
#define SPI_DMA_BLK_COUNT(count) (((count) - 1) & 0xFFFF)
#define SPI_TX_FIFO 0x10
#define SPI_RX_FIFO 0x20
#define DATA_DIR_TX (1 << 0)
#define DATA_DIR_RX (1 << 1)
#define MAX_CHIP_SELECT 4
#define SPI_FIFO_DEPTH 4
#define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
struct tegra_sflash_data {
struct device *dev;
struct spi_master *master;
spinlock_t lock;
struct clk *clk;
struct reset_control *rst;
void __iomem *base;
unsigned irq;
u32 cur_speed;
struct spi_device *cur_spi;
unsigned cur_pos;
unsigned cur_len;
unsigned bytes_per_word;
unsigned cur_direction;
unsigned curr_xfer_words;
unsigned cur_rx_pos;
unsigned cur_tx_pos;
u32 tx_status;
u32 rx_status;
u32 status_reg;
u32 def_command_reg;
u32 command_reg;
u32 dma_control_reg;
struct completion xfer_completion;
struct spi_transfer *curr_xfer;
};
static int tegra_sflash_runtime_suspend(struct device *dev);
static int tegra_sflash_runtime_resume(struct device *dev);
static inline u32 tegra_sflash_readl(struct tegra_sflash_data *tsd,
unsigned long reg)
{
return readl(tsd->base + reg);
}
static inline void tegra_sflash_writel(struct tegra_sflash_data *tsd,
u32 val, unsigned long reg)
{
writel(val, tsd->base + reg);
}
static void tegra_sflash_clear_status(struct tegra_sflash_data *tsd)
{
/* Write 1 to clear status register */
tegra_sflash_writel(tsd, SPI_RDY | SPI_FIFO_ERROR, SPI_STATUS);
}
static unsigned tegra_sflash_calculate_curr_xfer_param(
struct spi_device *spi, struct tegra_sflash_data *tsd,
struct spi_transfer *t)
{
unsigned remain_len = t->len - tsd->cur_pos;
unsigned max_word;
tsd->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
max_word = remain_len / tsd->bytes_per_word;
if (max_word > SPI_FIFO_DEPTH)
max_word = SPI_FIFO_DEPTH;
tsd->curr_xfer_words = max_word;
return max_word;
}
static unsigned tegra_sflash_fill_tx_fifo_from_client_txbuf(
struct tegra_sflash_data *tsd, struct spi_transfer *t)
{
unsigned nbytes;
u32 status;
unsigned max_n_32bit = tsd->curr_xfer_words;
u8 *tx_buf = (u8 *)t->tx_buf + tsd->cur_tx_pos;
if (max_n_32bit > SPI_FIFO_DEPTH)
max_n_32bit = SPI_FIFO_DEPTH;
nbytes = max_n_32bit * tsd->bytes_per_word;
status = tegra_sflash_readl(tsd, SPI_STATUS);
while (!(status & SPI_TXF_FULL)) {
int i;
u32 x = 0;
for (i = 0; nbytes && (i < tsd->bytes_per_word);
i++, nbytes--)
x |= (u32)(*tx_buf++) << (i * 8);
tegra_sflash_writel(tsd, x, SPI_TX_FIFO);
if (!nbytes)
break;
status = tegra_sflash_readl(tsd, SPI_STATUS);
}
tsd->cur_tx_pos += max_n_32bit * tsd->bytes_per_word;
return max_n_32bit;
}
static int tegra_sflash_read_rx_fifo_to_client_rxbuf(
struct tegra_sflash_data *tsd, struct spi_transfer *t)
{
u32 status;
unsigned int read_words = 0;
u8 *rx_buf = (u8 *)t->rx_buf + tsd->cur_rx_pos;
status = tegra_sflash_readl(tsd, SPI_STATUS);
while (!(status & SPI_RXF_EMPTY)) {
int i;
u32 x = tegra_sflash_readl(tsd, SPI_RX_FIFO);
for (i = 0; (i < tsd->bytes_per_word); i++)
*rx_buf++ = (x >> (i*8)) & 0xFF;
read_words++;
status = tegra_sflash_readl(tsd, SPI_STATUS);
}
tsd->cur_rx_pos += read_words * tsd->bytes_per_word;
return 0;
}
static int tegra_sflash_start_cpu_based_transfer(
struct tegra_sflash_data *tsd, struct spi_transfer *t)
{
u32 val = 0;
unsigned cur_words;
if (tsd->cur_direction & DATA_DIR_TX)
val |= SPI_IE_TXC;
if (tsd->cur_direction & DATA_DIR_RX)
val |= SPI_IE_RXC;
tegra_sflash_writel(tsd, val, SPI_DMA_CTL);
tsd->dma_control_reg = val;
if (tsd->cur_direction & DATA_DIR_TX)
cur_words = tegra_sflash_fill_tx_fifo_from_client_txbuf(tsd, t);
else
cur_words = tsd->curr_xfer_words;
val |= SPI_DMA_BLK_COUNT(cur_words);
tegra_sflash_writel(tsd, val, SPI_DMA_CTL);
tsd->dma_control_reg = val;
val |= SPI_DMA_EN;
tegra_sflash_writel(tsd, val, SPI_DMA_CTL);
return 0;
}
static int tegra_sflash_start_transfer_one(struct spi_device *spi,
struct spi_transfer *t, bool is_first_of_msg,
bool is_single_xfer)
{
struct tegra_sflash_data *tsd = spi_master_get_devdata(spi->master);
u32 speed;
u32 command;
speed = t->speed_hz;
if (speed != tsd->cur_speed) {
clk_set_rate(tsd->clk, speed);
tsd->cur_speed = speed;
}
tsd->cur_spi = spi;
tsd->cur_pos = 0;
tsd->cur_rx_pos = 0;
tsd->cur_tx_pos = 0;
tsd->curr_xfer = t;
tegra_sflash_calculate_curr_xfer_param(spi, tsd, t);
if (is_first_of_msg) {
command = tsd->def_command_reg;
command |= SPI_BIT_LENGTH(t->bits_per_word - 1);
command |= SPI_CS_VAL_HIGH;
command &= ~SPI_MODES;
if (spi->mode & SPI_CPHA)
command |= SPI_CK_SDA_FALLING;
if (spi->mode & SPI_CPOL)
command |= SPI_ACTIVE_SCLK_DRIVE_HIGH;
else
command |= SPI_ACTIVE_SCLK_DRIVE_LOW;
command |= SPI_CS0_EN << spi_get_chipselect(spi, 0);
} else {
command = tsd->command_reg;
command &= ~SPI_BIT_LENGTH(~0);
command |= SPI_BIT_LENGTH(t->bits_per_word - 1);
command &= ~(SPI_RX_EN | SPI_TX_EN);
}
tsd->cur_direction = 0;
if (t->rx_buf) {
command |= SPI_RX_EN;
tsd->cur_direction |= DATA_DIR_RX;
}
if (t->tx_buf) {
command |= SPI_TX_EN;
tsd->cur_direction |= DATA_DIR_TX;
}
tegra_sflash_writel(tsd, command, SPI_COMMAND);
tsd->command_reg = command;
return tegra_sflash_start_cpu_based_transfer(tsd, t);
}
static int tegra_sflash_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
bool is_first_msg = true;
int single_xfer;
struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
struct spi_transfer *xfer;
struct spi_device *spi = msg->spi;
int ret;
msg->status = 0;
msg->actual_length = 0;
single_xfer = list_is_singular(&msg->transfers);
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
reinit_completion(&tsd->xfer_completion);
ret = tegra_sflash_start_transfer_one(spi, xfer,
is_first_msg, single_xfer);
if (ret < 0) {
dev_err(tsd->dev,
"spi can not start transfer, err %d\n", ret);
goto exit;
}
is_first_msg = false;
ret = wait_for_completion_timeout(&tsd->xfer_completion,
SPI_DMA_TIMEOUT);
if (WARN_ON(ret == 0)) {
dev_err(tsd->dev,
"spi transfer timeout, err %d\n", ret);
ret = -EIO;
goto exit;
}
if (tsd->tx_status || tsd->rx_status) {
dev_err(tsd->dev, "Error in Transfer\n");
ret = -EIO;
goto exit;
}
msg->actual_length += xfer->len;
if (xfer->cs_change && xfer->delay.value) {
tegra_sflash_writel(tsd, tsd->def_command_reg,
SPI_COMMAND);
spi_transfer_delay_exec(xfer);
}
}
ret = 0;
exit:
tegra_sflash_writel(tsd, tsd->def_command_reg, SPI_COMMAND);
msg->status = ret;
spi_finalize_current_message(master);
return ret;
}
static irqreturn_t handle_cpu_based_xfer(struct tegra_sflash_data *tsd)
{
struct spi_transfer *t = tsd->curr_xfer;
spin_lock(&tsd->lock);
if (tsd->tx_status || tsd->rx_status || (tsd->status_reg & SPI_BSY)) {
dev_err(tsd->dev,
"CpuXfer ERROR bit set 0x%x\n", tsd->status_reg);
dev_err(tsd->dev,
"CpuXfer 0x%08x:0x%08x\n", tsd->command_reg,
tsd->dma_control_reg);
reset_control_assert(tsd->rst);
udelay(2);
reset_control_deassert(tsd->rst);
complete(&tsd->xfer_completion);
goto exit;
}
if (tsd->cur_direction & DATA_DIR_RX)
tegra_sflash_read_rx_fifo_to_client_rxbuf(tsd, t);
if (tsd->cur_direction & DATA_DIR_TX)
tsd->cur_pos = tsd->cur_tx_pos;
else
tsd->cur_pos = tsd->cur_rx_pos;
if (tsd->cur_pos == t->len) {
complete(&tsd->xfer_completion);
goto exit;
}
tegra_sflash_calculate_curr_xfer_param(tsd->cur_spi, tsd, t);
tegra_sflash_start_cpu_based_transfer(tsd, t);
exit:
spin_unlock(&tsd->lock);
return IRQ_HANDLED;
}
static irqreturn_t tegra_sflash_isr(int irq, void *context_data)
{
struct tegra_sflash_data *tsd = context_data;
tsd->status_reg = tegra_sflash_readl(tsd, SPI_STATUS);
if (tsd->cur_direction & DATA_DIR_TX)
tsd->tx_status = tsd->status_reg & SPI_TX_OVF;
if (tsd->cur_direction & DATA_DIR_RX)
tsd->rx_status = tsd->status_reg & SPI_RX_UNF;
tegra_sflash_clear_status(tsd);
return handle_cpu_based_xfer(tsd);
}
static const struct of_device_id tegra_sflash_of_match[] = {
{ .compatible = "nvidia,tegra20-sflash", },
{}
};
MODULE_DEVICE_TABLE(of, tegra_sflash_of_match);
static int tegra_sflash_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct tegra_sflash_data *tsd;
int ret;
const struct of_device_id *match;
match = of_match_device(tegra_sflash_of_match, &pdev->dev);
if (!match) {
dev_err(&pdev->dev, "Error: No device match found\n");
return -ENODEV;
}
master = spi_alloc_master(&pdev->dev, sizeof(*tsd));
if (!master) {
dev_err(&pdev->dev, "master allocation failed\n");
return -ENOMEM;
}
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA;
master->transfer_one_message = tegra_sflash_transfer_one_message;
master->auto_runtime_pm = true;
master->num_chipselect = MAX_CHIP_SELECT;
platform_set_drvdata(pdev, master);
tsd = spi_master_get_devdata(master);
tsd->master = master;
tsd->dev = &pdev->dev;
spin_lock_init(&tsd->lock);
if (of_property_read_u32(tsd->dev->of_node, "spi-max-frequency",
&master->max_speed_hz))
master->max_speed_hz = 25000000; /* 25MHz */
tsd->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(tsd->base)) {
ret = PTR_ERR(tsd->base);
goto exit_free_master;
}
tsd->irq = platform_get_irq(pdev, 0);
ret = request_irq(tsd->irq, tegra_sflash_isr, 0,
dev_name(&pdev->dev), tsd);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
tsd->irq);
goto exit_free_master;
}
tsd->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(tsd->clk)) {
dev_err(&pdev->dev, "can not get clock\n");
ret = PTR_ERR(tsd->clk);
goto exit_free_irq;
}
tsd->rst = devm_reset_control_get_exclusive(&pdev->dev, "spi");
if (IS_ERR(tsd->rst)) {
dev_err(&pdev->dev, "can not get reset\n");
ret = PTR_ERR(tsd->rst);
goto exit_free_irq;
}
init_completion(&tsd->xfer_completion);
pm_runtime_enable(&pdev->dev);
if (!pm_runtime_enabled(&pdev->dev)) {
ret = tegra_sflash_runtime_resume(&pdev->dev);
if (ret)
goto exit_pm_disable;
}
ret = pm_runtime_resume_and_get(&pdev->dev);
if (ret < 0) {
dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
goto exit_pm_disable;
}
/* Reset controller */
reset_control_assert(tsd->rst);
udelay(2);
reset_control_deassert(tsd->rst);
tsd->def_command_reg = SPI_M_S | SPI_CS_SW;
tegra_sflash_writel(tsd, tsd->def_command_reg, SPI_COMMAND);
pm_runtime_put(&pdev->dev);
master->dev.of_node = pdev->dev.of_node;
ret = devm_spi_register_master(&pdev->dev, master);
if (ret < 0) {
dev_err(&pdev->dev, "can not register to master err %d\n", ret);
goto exit_pm_disable;
}
return ret;
exit_pm_disable:
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_sflash_runtime_suspend(&pdev->dev);
exit_free_irq:
free_irq(tsd->irq, tsd);
exit_free_master:
spi_master_put(master);
return ret;
}
static void tegra_sflash_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
free_irq(tsd->irq, tsd);
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_sflash_runtime_suspend(&pdev->dev);
}
#ifdef CONFIG_PM_SLEEP
static int tegra_sflash_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
return spi_master_suspend(master);
}
static int tegra_sflash_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
int ret;
ret = pm_runtime_resume_and_get(dev);
if (ret < 0) {
dev_err(dev, "pm runtime failed, e = %d\n", ret);
return ret;
}
tegra_sflash_writel(tsd, tsd->command_reg, SPI_COMMAND);
pm_runtime_put(dev);
return spi_master_resume(master);
}
#endif
static int tegra_sflash_runtime_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
/* Flush all write which are in PPSB queue by reading back */
tegra_sflash_readl(tsd, SPI_COMMAND);
clk_disable_unprepare(tsd->clk);
return 0;
}
static int tegra_sflash_runtime_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_sflash_data *tsd = spi_master_get_devdata(master);
int ret;
ret = clk_prepare_enable(tsd->clk);
if (ret < 0) {
dev_err(tsd->dev, "clk_prepare failed: %d\n", ret);
return ret;
}
return 0;
}
static const struct dev_pm_ops slink_pm_ops = {
SET_RUNTIME_PM_OPS(tegra_sflash_runtime_suspend,
tegra_sflash_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(tegra_sflash_suspend, tegra_sflash_resume)
};
static struct platform_driver tegra_sflash_driver = {
.driver = {
.name = "spi-tegra-sflash",
.pm = &slink_pm_ops,
.of_match_table = tegra_sflash_of_match,
},
.probe = tegra_sflash_probe,
.remove_new = tegra_sflash_remove,
};
module_platform_driver(tegra_sflash_driver);
MODULE_ALIAS("platform:spi-tegra-sflash");
MODULE_DESCRIPTION("NVIDIA Tegra20 Serial Flash Controller Driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");