linux/drivers/spi/spi-geni-qcom.c

688 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/log2.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/qcom-geni-se.h>
#include <linux/spi/spi.h>
#include <linux/spinlock.h>
/* SPI SE specific registers and respective register fields */
#define SE_SPI_CPHA 0x224
#define CPHA BIT(0)
#define SE_SPI_LOOPBACK 0x22c
#define LOOPBACK_ENABLE 0x1
#define NORMAL_MODE 0x0
#define LOOPBACK_MSK GENMASK(1, 0)
#define SE_SPI_CPOL 0x230
#define CPOL BIT(2)
#define SE_SPI_DEMUX_OUTPUT_INV 0x24c
#define CS_DEMUX_OUTPUT_INV_MSK GENMASK(3, 0)
#define SE_SPI_DEMUX_SEL 0x250
#define CS_DEMUX_OUTPUT_SEL GENMASK(3, 0)
#define SE_SPI_TRANS_CFG 0x25c
#define CS_TOGGLE BIT(0)
#define SE_SPI_WORD_LEN 0x268
#define WORD_LEN_MSK GENMASK(9, 0)
#define MIN_WORD_LEN 4
#define SE_SPI_TX_TRANS_LEN 0x26c
#define SE_SPI_RX_TRANS_LEN 0x270
#define TRANS_LEN_MSK GENMASK(23, 0)
#define SE_SPI_PRE_POST_CMD_DLY 0x274
#define SE_SPI_DELAY_COUNTERS 0x278
#define SPI_INTER_WORDS_DELAY_MSK GENMASK(9, 0)
#define SPI_CS_CLK_DELAY_MSK GENMASK(19, 10)
#define SPI_CS_CLK_DELAY_SHFT 10
/* M_CMD OP codes for SPI */
#define SPI_TX_ONLY 1
#define SPI_RX_ONLY 2
#define SPI_FULL_DUPLEX 3
#define SPI_TX_RX 7
#define SPI_CS_ASSERT 8
#define SPI_CS_DEASSERT 9
#define SPI_SCK_ONLY 10
/* M_CMD params for SPI */
#define SPI_PRE_CMD_DELAY BIT(0)
#define TIMESTAMP_BEFORE BIT(1)
#define FRAGMENTATION BIT(2)
#define TIMESTAMP_AFTER BIT(3)
#define POST_CMD_DELAY BIT(4)
enum spi_m_cmd_opcode {
CMD_NONE,
CMD_XFER,
CMD_CS,
CMD_CANCEL,
};
struct spi_geni_master {
struct geni_se se;
struct device *dev;
u32 tx_fifo_depth;
u32 fifo_width_bits;
u32 tx_wm;
unsigned long cur_speed_hz;
unsigned int cur_bits_per_word;
unsigned int tx_rem_bytes;
unsigned int rx_rem_bytes;
const struct spi_transfer *cur_xfer;
struct completion xfer_done;
unsigned int oversampling;
spinlock_t lock;
enum spi_m_cmd_opcode cur_mcmd;
int irq;
};
static int get_spi_clk_cfg(unsigned int speed_hz,
struct spi_geni_master *mas,
unsigned int *clk_idx,
unsigned int *clk_div)
{
unsigned long sclk_freq;
unsigned int actual_hz;
struct geni_se *se = &mas->se;
int ret;
ret = geni_se_clk_freq_match(&mas->se,
speed_hz * mas->oversampling,
clk_idx, &sclk_freq, false);
if (ret) {
dev_err(mas->dev, "Failed(%d) to find src clk for %dHz\n",
ret, speed_hz);
return ret;
}
*clk_div = DIV_ROUND_UP(sclk_freq, mas->oversampling * speed_hz);
actual_hz = sclk_freq / (mas->oversampling * *clk_div);
dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
actual_hz, sclk_freq, *clk_idx, *clk_div);
ret = clk_set_rate(se->clk, sclk_freq);
if (ret)
dev_err(mas->dev, "clk_set_rate failed %d\n", ret);
return ret;
}
static void handle_fifo_timeout(struct spi_master *spi,
struct spi_message *msg)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
unsigned long time_left, flags;
struct geni_se *se = &mas->se;
spin_lock_irqsave(&mas->lock, flags);
reinit_completion(&mas->xfer_done);
mas->cur_mcmd = CMD_CANCEL;
geni_se_cancel_m_cmd(se);
writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
spin_unlock_irqrestore(&mas->lock, flags);
time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
if (time_left)
return;
spin_lock_irqsave(&mas->lock, flags);
reinit_completion(&mas->xfer_done);
geni_se_abort_m_cmd(se);
spin_unlock_irqrestore(&mas->lock, flags);
time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
if (!time_left)
dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
}
static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
{
struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
struct spi_master *spi = dev_get_drvdata(mas->dev);
struct geni_se *se = &mas->se;
unsigned long time_left;
reinit_completion(&mas->xfer_done);
pm_runtime_get_sync(mas->dev);
if (!(slv->mode & SPI_CS_HIGH))
set_flag = !set_flag;
mas->cur_mcmd = CMD_CS;
if (set_flag)
geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
else
geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
if (!time_left)
handle_fifo_timeout(spi, NULL);
pm_runtime_put(mas->dev);
}
static void spi_setup_word_len(struct spi_geni_master *mas, u16 mode,
unsigned int bits_per_word)
{
unsigned int pack_words;
bool msb_first = (mode & SPI_LSB_FIRST) ? false : true;
struct geni_se *se = &mas->se;
u32 word_len;
word_len = readl(se->base + SE_SPI_WORD_LEN);
/*
* If bits_per_word isn't a byte aligned value, set the packing to be
* 1 SPI word per FIFO word.
*/
if (!(mas->fifo_width_bits % bits_per_word))
pack_words = mas->fifo_width_bits / bits_per_word;
else
pack_words = 1;
word_len &= ~WORD_LEN_MSK;
word_len |= ((bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK);
geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first,
true, true);
writel(word_len, se->base + SE_SPI_WORD_LEN);
}
static int setup_fifo_params(struct spi_device *spi_slv,
struct spi_master *spi)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
struct geni_se *se = &mas->se;
u32 loopback_cfg, cpol, cpha, demux_output_inv;
u32 demux_sel, clk_sel, m_clk_cfg, idx, div;
int ret;
loopback_cfg = readl(se->base + SE_SPI_LOOPBACK);
cpol = readl(se->base + SE_SPI_CPOL);
cpha = readl(se->base + SE_SPI_CPHA);
demux_output_inv = 0;
loopback_cfg &= ~LOOPBACK_MSK;
cpol &= ~CPOL;
cpha &= ~CPHA;
if (spi_slv->mode & SPI_LOOP)
loopback_cfg |= LOOPBACK_ENABLE;
if (spi_slv->mode & SPI_CPOL)
cpol |= CPOL;
if (spi_slv->mode & SPI_CPHA)
cpha |= CPHA;
if (spi_slv->mode & SPI_CS_HIGH)
demux_output_inv = BIT(spi_slv->chip_select);
demux_sel = spi_slv->chip_select;
mas->cur_speed_hz = spi_slv->max_speed_hz;
mas->cur_bits_per_word = spi_slv->bits_per_word;
ret = get_spi_clk_cfg(mas->cur_speed_hz, mas, &idx, &div);
if (ret) {
dev_err(mas->dev, "Err setting clks ret(%d) for %ld\n",
ret, mas->cur_speed_hz);
return ret;
}
clk_sel = idx & CLK_SEL_MSK;
m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
writel(loopback_cfg, se->base + SE_SPI_LOOPBACK);
writel(demux_sel, se->base + SE_SPI_DEMUX_SEL);
writel(cpha, se->base + SE_SPI_CPHA);
writel(cpol, se->base + SE_SPI_CPOL);
writel(demux_output_inv, se->base + SE_SPI_DEMUX_OUTPUT_INV);
writel(clk_sel, se->base + SE_GENI_CLK_SEL);
writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
return 0;
}
static int spi_geni_prepare_message(struct spi_master *spi,
struct spi_message *spi_msg)
{
int ret;
struct spi_geni_master *mas = spi_master_get_devdata(spi);
struct geni_se *se = &mas->se;
geni_se_select_mode(se, GENI_SE_FIFO);
ret = setup_fifo_params(spi_msg->spi, spi);
if (ret)
dev_err(mas->dev, "Couldn't select mode %d\n", ret);
return ret;
}
static int spi_geni_init(struct spi_geni_master *mas)
{
struct geni_se *se = &mas->se;
unsigned int proto, major, minor, ver;
pm_runtime_get_sync(mas->dev);
proto = geni_se_read_proto(se);
if (proto != GENI_SE_SPI) {
dev_err(mas->dev, "Invalid proto %d\n", proto);
pm_runtime_put(mas->dev);
return -ENXIO;
}
mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se);
/* Width of Tx and Rx FIFO is same */
mas->fifo_width_bits = geni_se_get_tx_fifo_width(se);
/*
* Hardware programming guide suggests to configure
* RX FIFO RFR level to fifo_depth-2.
*/
geni_se_init(se, 0x0, mas->tx_fifo_depth - 2);
/* Transmit an entire FIFO worth of data per IRQ */
mas->tx_wm = 1;
ver = geni_se_get_qup_hw_version(se);
major = GENI_SE_VERSION_MAJOR(ver);
minor = GENI_SE_VERSION_MINOR(ver);
if (major == 1 && minor == 0)
mas->oversampling = 2;
else
mas->oversampling = 1;
pm_runtime_put(mas->dev);
return 0;
}
static void setup_fifo_xfer(struct spi_transfer *xfer,
struct spi_geni_master *mas,
u16 mode, struct spi_master *spi)
{
u32 m_cmd = 0;
u32 spi_tx_cfg, len;
struct geni_se *se = &mas->se;
spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
if (xfer->bits_per_word != mas->cur_bits_per_word) {
spi_setup_word_len(mas, mode, xfer->bits_per_word);
mas->cur_bits_per_word = xfer->bits_per_word;
}
/* Speed and bits per word can be overridden per transfer */
if (xfer->speed_hz != mas->cur_speed_hz) {
int ret;
u32 clk_sel, m_clk_cfg;
unsigned int idx, div;
ret = get_spi_clk_cfg(xfer->speed_hz, mas, &idx, &div);
if (ret) {
dev_err(mas->dev, "Err setting clks:%d\n", ret);
return;
}
/*
* SPI core clock gets configured with the requested frequency
* or the frequency closer to the requested frequency.
* For that reason requested frequency is stored in the
* cur_speed_hz and referred in the consecutive transfer instead
* of calling clk_get_rate() API.
*/
mas->cur_speed_hz = xfer->speed_hz;
clk_sel = idx & CLK_SEL_MSK;
m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
writel(clk_sel, se->base + SE_GENI_CLK_SEL);
writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
}
mas->tx_rem_bytes = 0;
mas->rx_rem_bytes = 0;
if (xfer->tx_buf && xfer->rx_buf)
m_cmd = SPI_FULL_DUPLEX;
else if (xfer->tx_buf)
m_cmd = SPI_TX_ONLY;
else if (xfer->rx_buf)
m_cmd = SPI_RX_ONLY;
spi_tx_cfg &= ~CS_TOGGLE;
if (!(mas->cur_bits_per_word % MIN_WORD_LEN))
len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word;
else
len = xfer->len / (mas->cur_bits_per_word / BITS_PER_BYTE + 1);
len &= TRANS_LEN_MSK;
mas->cur_xfer = xfer;
if (m_cmd & SPI_TX_ONLY) {
mas->tx_rem_bytes = xfer->len;
writel(len, se->base + SE_SPI_TX_TRANS_LEN);
}
if (m_cmd & SPI_RX_ONLY) {
writel(len, se->base + SE_SPI_RX_TRANS_LEN);
mas->rx_rem_bytes = xfer->len;
}
writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
mas->cur_mcmd = CMD_XFER;
geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
/*
* TX_WATERMARK_REG should be set after SPI configuration and
* setting up GENI SE engine, as driver starts data transfer
* for the watermark interrupt.
*/
if (m_cmd & SPI_TX_ONLY)
writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
}
static int spi_geni_transfer_one(struct spi_master *spi,
struct spi_device *slv,
struct spi_transfer *xfer)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
/* Terminate and return success for 0 byte length transfer */
if (!xfer->len)
return 0;
setup_fifo_xfer(xfer, mas, slv->mode, spi);
return 1;
}
static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas)
{
/*
* Calculate how many bytes we'll put in each FIFO word. If the
* transfer words don't pack cleanly into a FIFO word we'll just put
* one transfer word in each FIFO word. If they do pack we'll pack 'em.
*/
if (mas->fifo_width_bits % mas->cur_bits_per_word)
return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word,
BITS_PER_BYTE));
return mas->fifo_width_bits / BITS_PER_BYTE;
}
static void geni_spi_handle_tx(struct spi_geni_master *mas)
{
struct geni_se *se = &mas->se;
unsigned int max_bytes;
const u8 *tx_buf;
unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
unsigned int i = 0;
max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word;
if (mas->tx_rem_bytes < max_bytes)
max_bytes = mas->tx_rem_bytes;
tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes;
while (i < max_bytes) {
unsigned int j;
unsigned int bytes_to_write;
u32 fifo_word = 0;
u8 *fifo_byte = (u8 *)&fifo_word;
bytes_to_write = min(bytes_per_fifo_word, max_bytes - i);
for (j = 0; j < bytes_to_write; j++)
fifo_byte[j] = tx_buf[i++];
iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1);
}
mas->tx_rem_bytes -= max_bytes;
if (!mas->tx_rem_bytes)
writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
}
static void geni_spi_handle_rx(struct spi_geni_master *mas)
{
struct geni_se *se = &mas->se;
u32 rx_fifo_status;
unsigned int rx_bytes;
unsigned int rx_last_byte_valid;
u8 *rx_buf;
unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
unsigned int i = 0;
rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS);
rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word;
if (rx_fifo_status & RX_LAST) {
rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK;
rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT;
if (rx_last_byte_valid && rx_last_byte_valid < 4)
rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid;
}
if (mas->rx_rem_bytes < rx_bytes)
rx_bytes = mas->rx_rem_bytes;
rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes;
while (i < rx_bytes) {
u32 fifo_word = 0;
u8 *fifo_byte = (u8 *)&fifo_word;
unsigned int bytes_to_read;
unsigned int j;
bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i);
ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1);
for (j = 0; j < bytes_to_read; j++)
rx_buf[i++] = fifo_byte[j];
}
mas->rx_rem_bytes -= rx_bytes;
}
static irqreturn_t geni_spi_isr(int irq, void *data)
{
struct spi_master *spi = data;
struct spi_geni_master *mas = spi_master_get_devdata(spi);
struct geni_se *se = &mas->se;
u32 m_irq;
unsigned long flags;
if (mas->cur_mcmd == CMD_NONE)
return IRQ_NONE;
spin_lock_irqsave(&mas->lock, flags);
m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
geni_spi_handle_rx(mas);
if (m_irq & M_TX_FIFO_WATERMARK_EN)
geni_spi_handle_tx(mas);
if (m_irq & M_CMD_DONE_EN) {
if (mas->cur_mcmd == CMD_XFER)
spi_finalize_current_transfer(spi);
else if (mas->cur_mcmd == CMD_CS)
complete(&mas->xfer_done);
mas->cur_mcmd = CMD_NONE;
/*
* If this happens, then a CMD_DONE came before all the Tx
* buffer bytes were sent out. This is unusual, log this
* condition and disable the WM interrupt to prevent the
* system from stalling due an interrupt storm.
* If this happens when all Rx bytes haven't been received, log
* the condition.
* The only known time this can happen is if bits_per_word != 8
* and some registers that expect xfer lengths in num spi_words
* weren't written correctly.
*/
if (mas->tx_rem_bytes) {
writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
mas->tx_rem_bytes, mas->cur_bits_per_word);
}
if (mas->rx_rem_bytes)
dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
mas->rx_rem_bytes, mas->cur_bits_per_word);
}
if ((m_irq & M_CMD_CANCEL_EN) || (m_irq & M_CMD_ABORT_EN)) {
mas->cur_mcmd = CMD_NONE;
complete(&mas->xfer_done);
}
writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
spin_unlock_irqrestore(&mas->lock, flags);
return IRQ_HANDLED;
}
static int spi_geni_probe(struct platform_device *pdev)
{
int ret, irq;
struct spi_master *spi;
struct spi_geni_master *mas;
void __iomem *base;
struct clk *clk;
struct device *dev = &pdev->dev;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
clk = devm_clk_get(dev, "se");
if (IS_ERR(clk))
return PTR_ERR(clk);
spi = spi_alloc_master(dev, sizeof(*mas));
if (!spi)
return -ENOMEM;
platform_set_drvdata(pdev, spi);
mas = spi_master_get_devdata(spi);
mas->irq = irq;
mas->dev = dev;
mas->se.dev = dev;
mas->se.wrapper = dev_get_drvdata(dev->parent);
mas->se.base = base;
mas->se.clk = clk;
spi->bus_num = -1;
spi->dev.of_node = dev->of_node;
spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
spi->num_chipselect = 4;
spi->max_speed_hz = 50000000;
spi->prepare_message = spi_geni_prepare_message;
spi->transfer_one = spi_geni_transfer_one;
spi->auto_runtime_pm = true;
spi->handle_err = handle_fifo_timeout;
spi->set_cs = spi_geni_set_cs;
init_completion(&mas->xfer_done);
spin_lock_init(&mas->lock);
pm_runtime_enable(dev);
ret = spi_geni_init(mas);
if (ret)
goto spi_geni_probe_runtime_disable;
ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);
if (ret)
goto spi_geni_probe_runtime_disable;
ret = spi_register_master(spi);
if (ret)
goto spi_geni_probe_free_irq;
return 0;
spi_geni_probe_free_irq:
free_irq(mas->irq, spi);
spi_geni_probe_runtime_disable:
pm_runtime_disable(dev);
spi_master_put(spi);
return ret;
}
static int spi_geni_remove(struct platform_device *pdev)
{
struct spi_master *spi = platform_get_drvdata(pdev);
struct spi_geni_master *mas = spi_master_get_devdata(spi);
/* Unregister _before_ disabling pm_runtime() so we stop transfers */
spi_unregister_master(spi);
free_irq(mas->irq, spi);
pm_runtime_disable(&pdev->dev);
return 0;
}
static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
{
struct spi_master *spi = dev_get_drvdata(dev);
struct spi_geni_master *mas = spi_master_get_devdata(spi);
return geni_se_resources_off(&mas->se);
}
static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
{
struct spi_master *spi = dev_get_drvdata(dev);
struct spi_geni_master *mas = spi_master_get_devdata(spi);
return geni_se_resources_on(&mas->se);
}
static int __maybe_unused spi_geni_suspend(struct device *dev)
{
struct spi_master *spi = dev_get_drvdata(dev);
int ret;
ret = spi_master_suspend(spi);
if (ret)
return ret;
ret = pm_runtime_force_suspend(dev);
if (ret)
spi_master_resume(spi);
return ret;
}
static int __maybe_unused spi_geni_resume(struct device *dev)
{
struct spi_master *spi = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_force_resume(dev);
if (ret)
return ret;
ret = spi_master_resume(spi);
if (ret)
pm_runtime_force_suspend(dev);
return ret;
}
static const struct dev_pm_ops spi_geni_pm_ops = {
SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend,
spi_geni_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, spi_geni_resume)
};
static const struct of_device_id spi_geni_dt_match[] = {
{ .compatible = "qcom,geni-spi" },
{}
};
MODULE_DEVICE_TABLE(of, spi_geni_dt_match);
static struct platform_driver spi_geni_driver = {
.probe = spi_geni_probe,
.remove = spi_geni_remove,
.driver = {
.name = "geni_spi",
.pm = &spi_geni_pm_ops,
.of_match_table = spi_geni_dt_match,
},
};
module_platform_driver(spi_geni_driver);
MODULE_DESCRIPTION("SPI driver for GENI based QUP cores");
MODULE_LICENSE("GPL v2");