spi-geni-qcom.c
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dma/qcom-gpi-dma.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_opp.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_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)
#define GSI_LOOPBACK_EN BIT(0)
#define GSI_CS_TOGGLE BIT(3)
#define GSI_CPHA BIT(4)
#define GSI_CPOL BIT(5)
struct spi_geni_master {
struct geni_se se;
struct device *dev;
u32 tx_fifo_depth;
u32 fifo_width_bits;
u32 tx_wm;
u32 last_mode;
unsigned long cur_speed_hz;
unsigned long cur_sclk_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 cs_done;
struct completion cancel_done;
struct completion abort_done;
unsigned int oversampling;
spinlock_t lock;
int irq;
bool cs_flag;
bool abort_failed;
struct dma_chan *tx;
struct dma_chan *rx;
int cur_xfer_mode;
};
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;
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 = dev_pm_opp_set_rate(mas->dev, sclk_freq);
if (ret)
dev_err(mas->dev, "dev_pm_opp_set_rate failed %d\n", ret);
else
mas->cur_sclk_hz = sclk_freq;
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;
struct geni_se *se = &mas->se;
spin_lock_irq(&mas->lock);
reinit_completion(&mas->cancel_done);
writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
mas->cur_xfer = NULL;
geni_se_cancel_m_cmd(se);
spin_unlock_irq(&mas->lock);
time_left = wait_for_completion_timeout(&mas->cancel_done, HZ);
if (time_left)
return;
spin_lock_irq(&mas->lock);
reinit_completion(&mas->abort_done);
geni_se_abort_m_cmd(se);
spin_unlock_irq(&mas->lock);
time_left = wait_for_completion_timeout(&mas->abort_done, HZ);
if (!time_left) {
dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
/*
* No need for a lock since SPI core has a lock and we never
* access this from an interrupt.
*/
mas->abort_failed = true;
}
}
static void handle_gpi_timeout(struct spi_master *spi, struct spi_message *msg)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
dmaengine_terminate_sync(mas->tx);
dmaengine_terminate_sync(mas->rx);
}
static void spi_geni_handle_err(struct spi_master *spi, struct spi_message *msg)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
switch (mas->cur_xfer_mode) {
case GENI_SE_FIFO:
handle_fifo_timeout(spi, msg);
break;
case GENI_GPI_DMA:
handle_gpi_timeout(spi, msg);
break;
default:
dev_err(mas->dev, "Abort on Mode:%d not supported", mas->cur_xfer_mode);
}
}
static bool spi_geni_is_abort_still_pending(struct spi_geni_master *mas)
{
struct geni_se *se = &mas->se;
u32 m_irq, m_irq_en;
if (!mas->abort_failed)
return false;
/*
* The only known case where a transfer times out and then a cancel
* times out then an abort times out is if something is blocking our
* interrupt handler from running. Avoid starting any new transfers
* until that sorts itself out.
*/
spin_lock_irq(&mas->lock);
m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
m_irq_en = readl(se->base + SE_GENI_M_IRQ_EN);
spin_unlock_irq(&mas->lock);
if (m_irq & m_irq_en) {
dev_err(mas->dev, "Interrupts pending after abort: %#010x\n",
m_irq & m_irq_en);
return true;
}
/*
* If we're here the problem resolved itself so no need to check more
* on future transfers.
*/
mas->abort_failed = false;
return false;
}
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;
if (!(slv->mode & SPI_CS_HIGH))
set_flag = !set_flag;
if (set_flag == mas->cs_flag)
return;
pm_runtime_get_sync(mas->dev);
if (spi_geni_is_abort_still_pending(mas)) {
dev_err(mas->dev, "Can't set chip select\n");
goto exit;
}
spin_lock_irq(&mas->lock);
if (mas->cur_xfer) {
dev_err(mas->dev, "Can't set CS when prev xfer running\n");
spin_unlock_irq(&mas->lock);
goto exit;
}
mas->cs_flag = set_flag;
reinit_completion(&mas->cs_done);
if (set_flag)
geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
else
geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
spin_unlock_irq(&mas->lock);
time_left = wait_for_completion_timeout(&mas->cs_done, HZ);
if (!time_left) {
dev_warn(mas->dev, "Timeout setting chip select\n");
handle_fifo_timeout(spi, NULL);
}
exit:
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;
/*
* 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;
geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first,
true, true);
word_len = (bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK;
writel(word_len, se->base + SE_SPI_WORD_LEN);
}
static int geni_spi_set_clock_and_bw(struct spi_geni_master *mas,
unsigned long clk_hz)
{
u32 clk_sel, m_clk_cfg, idx, div;
struct geni_se *se = &mas->se;
int ret;
if (clk_hz == mas->cur_speed_hz)
return 0;
ret = get_spi_clk_cfg(clk_hz, mas, &idx, &div);
if (ret) {
dev_err(mas->dev, "Err setting clk to %lu: %d\n", clk_hz, ret);
return ret;
}
/*
* 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 = clk_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);
/* Set BW quota for CPU as driver supports FIFO mode only. */
se->icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(mas->cur_speed_hz);
ret = geni_icc_set_bw(se);
if (ret)
return ret;
return 0;
}
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 = 0, cpol = 0, cpha = 0, demux_output_inv = 0;
u32 demux_sel;
if (mas->last_mode != spi_slv->mode) {
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_bits_per_word = spi_slv->bits_per_word;
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);
mas->last_mode = spi_slv->mode;
}
return geni_spi_set_clock_and_bw(mas, spi_slv->max_speed_hz);
}
static void
spi_gsi_callback_result(void *cb, const struct dmaengine_result *result)
{
struct spi_master *spi = cb;
spi->cur_msg->status = -EIO;
if (result->result != DMA_TRANS_NOERROR) {
dev_err(&spi->dev, "DMA txn failed: %d\n", result->result);
spi_finalize_current_transfer(spi);
return;
}
if (!result->residue) {
spi->cur_msg->status = 0;
dev_dbg(&spi->dev, "DMA txn completed\n");
} else {
dev_err(&spi->dev, "DMA xfer has pending: %d\n", result->residue);
}
spi_finalize_current_transfer(spi);
}
static int setup_gsi_xfer(struct spi_transfer *xfer, struct spi_geni_master *mas,
struct spi_device *spi_slv, struct spi_master *spi)
{
unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
struct dma_slave_config config = {};
struct gpi_spi_config peripheral = {};
struct dma_async_tx_descriptor *tx_desc, *rx_desc;
int ret;
config.peripheral_config = &peripheral;
config.peripheral_size = sizeof(peripheral);
peripheral.set_config = true;
if (xfer->bits_per_word != mas->cur_bits_per_word ||
xfer->speed_hz != mas->cur_speed_hz) {
mas->cur_bits_per_word = xfer->bits_per_word;
mas->cur_speed_hz = xfer->speed_hz;
}
if (xfer->tx_buf && xfer->rx_buf) {
peripheral.cmd = SPI_DUPLEX;
} else if (xfer->tx_buf) {
peripheral.cmd = SPI_TX;
peripheral.rx_len = 0;
} else if (xfer->rx_buf) {
peripheral.cmd = SPI_RX;
if (!(mas->cur_bits_per_word % MIN_WORD_LEN)) {
peripheral.rx_len = ((xfer->len << 3) / mas->cur_bits_per_word);
} else {
int bytes_per_word = (mas->cur_bits_per_word / BITS_PER_BYTE) + 1;
peripheral.rx_len = (xfer->len / bytes_per_word);
}
}
peripheral.loopback_en = !!(spi_slv->mode & SPI_LOOP);
peripheral.clock_pol_high = !!(spi_slv->mode & SPI_CPOL);
peripheral.data_pol_high = !!(spi_slv->mode & SPI_CPHA);
peripheral.cs = spi_slv->chip_select;
peripheral.pack_en = true;
peripheral.word_len = xfer->bits_per_word - MIN_WORD_LEN;
ret = get_spi_clk_cfg(mas->cur_speed_hz, mas,
&peripheral.clk_src, &peripheral.clk_div);
if (ret) {
dev_err(mas->dev, "Err in get_spi_clk_cfg() :%d\n", ret);
return ret;
}
if (!xfer->cs_change) {
if (!list_is_last(&xfer->transfer_list, &spi->cur_msg->transfers))
peripheral.fragmentation = FRAGMENTATION;
}
if (peripheral.cmd & SPI_RX) {
dmaengine_slave_config(mas->rx, &config);
rx_desc = dmaengine_prep_slave_sg(mas->rx, xfer->rx_sg.sgl, xfer->rx_sg.nents,
DMA_DEV_TO_MEM, flags);
if (!rx_desc) {
dev_err(mas->dev, "Err setting up rx desc\n");
return -EIO;
}
}
/*
* Prepare the TX always, even for RX or tx_buf being null, we would
* need TX to be prepared per GSI spec
*/
dmaengine_slave_config(mas->tx, &config);
tx_desc = dmaengine_prep_slave_sg(mas->tx, xfer->tx_sg.sgl, xfer->tx_sg.nents,
DMA_MEM_TO_DEV, flags);
if (!tx_desc) {
dev_err(mas->dev, "Err setting up tx desc\n");
return -EIO;
}
tx_desc->callback_result = spi_gsi_callback_result;
tx_desc->callback_param = spi;
if (peripheral.cmd & SPI_RX)
dmaengine_submit(rx_desc);
dmaengine_submit(tx_desc);
if (peripheral.cmd & SPI_RX)
dma_async_issue_pending(mas->rx);
dma_async_issue_pending(mas->tx);
return 1;
}
static bool geni_can_dma(struct spi_controller *ctlr,
struct spi_device *slv, struct spi_transfer *xfer)
{
struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
/* check if dma is supported */
return mas->cur_xfer_mode != GENI_SE_FIFO;
}
static int spi_geni_prepare_message(struct spi_master *spi,
struct spi_message *spi_msg)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
int ret;
switch (mas->cur_xfer_mode) {
case GENI_SE_FIFO:
if (spi_geni_is_abort_still_pending(mas))
return -EBUSY;
ret = setup_fifo_params(spi_msg->spi, spi);
if (ret)
dev_err(mas->dev, "Couldn't select mode %d\n", ret);
return ret;
case GENI_GPI_DMA:
/* nothing to do for GPI DMA */
return 0;
}
dev_err(mas->dev, "Mode not supported %d", mas->cur_xfer_mode);
return -EINVAL;
}
static int spi_geni_grab_gpi_chan(struct spi_geni_master *mas)
{
int ret;
mas->tx = dma_request_chan(mas->dev, "tx");
if (IS_ERR(mas->tx)) {
ret = dev_err_probe(mas->dev, PTR_ERR(mas->tx),
"Failed to get tx DMA ch\n");
goto err_tx;
}
mas->rx = dma_request_chan(mas->dev, "rx");
if (IS_ERR(mas->rx)) {
ret = dev_err_probe(mas->dev, PTR_ERR(mas->rx),
"Failed to get rx DMA ch\n");
goto err_rx;
}
return 0;
err_rx:
mas->rx = NULL;
dma_release_channel(mas->tx);
err_tx:
mas->tx = NULL;
return ret;
}
static void spi_geni_release_dma_chan(struct spi_geni_master *mas)
{
if (mas->rx) {
dma_release_channel(mas->rx);
mas->rx = NULL;
}
if (mas->tx) {
dma_release_channel(mas->tx);
mas->tx = NULL;
}
}
static int spi_geni_init(struct spi_geni_master *mas)
{
struct geni_se *se = &mas->se;
unsigned int proto, major, minor, ver;
u32 spi_tx_cfg, fifo_disable;
int ret = -ENXIO;
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);
goto out_pm;
}
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, mas->tx_fifo_depth - 3, 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;
fifo_disable = readl(se->base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
switch (fifo_disable) {
case 1:
ret = spi_geni_grab_gpi_chan(mas);
if (!ret) { /* success case */
mas->cur_xfer_mode = GENI_GPI_DMA;
geni_se_select_mode(se, GENI_GPI_DMA);
dev_dbg(mas->dev, "Using GPI DMA mode for SPI\n");
break;
}
/*
* in case of failure to get dma channel, we can still do the
* FIFO mode, so fallthrough
*/
dev_warn(mas->dev, "FIFO mode disabled, but couldn't get DMA, fall back to FIFO mode\n");
fallthrough;
case 0:
mas->cur_xfer_mode = GENI_SE_FIFO;
geni_se_select_mode(se, GENI_SE_FIFO);
ret = 0;
break;
}
/* We always control CS manually */
spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
spi_tx_cfg &= ~CS_TOGGLE;
writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
out_pm:
pm_runtime_put(mas->dev);
return ret;
}
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 bool 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;
/* Stop the watermark IRQ if nothing to send */
if (!mas->cur_xfer) {
writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
return false;
}
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);
return false;
}
return true;
}
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;
}
/* Clear out the FIFO and bail if nowhere to put it */
if (!mas->cur_xfer) {
for (i = 0; i < DIV_ROUND_UP(rx_bytes, bytes_per_fifo_word); i++)
readl(se->base + SE_GENI_RX_FIFOn);
return;
}
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 void setup_fifo_xfer(struct spi_transfer *xfer,
struct spi_geni_master *mas,
u16 mode, struct spi_master *spi)
{
u32 m_cmd = 0;
u32 len;
struct geni_se *se = &mas->se;
int ret;
/*
* Ensure that our interrupt handler isn't still running from some
* prior command before we start messing with the hardware behind
* its back. We don't need to _keep_ the lock here since we're only
* worried about racing with out interrupt handler. The SPI core
* already handles making sure that we're not trying to do two
* transfers at once or setting a chip select and doing a transfer
* concurrently.
*
* NOTE: we actually _can't_ hold the lock here because possibly we
* might call clk_set_rate() which needs to be able to sleep.
*/
spin_lock_irq(&mas->lock);
spin_unlock_irq(&mas->lock);
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 */
ret = geni_spi_set_clock_and_bw(mas, xfer->speed_hz);
if (ret)
return;
mas->tx_rem_bytes = 0;
mas->rx_rem_bytes = 0;
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 (xfer->tx_buf) {
m_cmd |= SPI_TX_ONLY;
mas->tx_rem_bytes = xfer->len;
writel(len, se->base + SE_SPI_TX_TRANS_LEN);
}
if (xfer->rx_buf) {
m_cmd |= SPI_RX_ONLY;
writel(len, se->base + SE_SPI_RX_TRANS_LEN);
mas->rx_rem_bytes = xfer->len;
}
/*
* Lock around right before we start the transfer since our
* interrupt could come in at any time now.
*/
spin_lock_irq(&mas->lock);
geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
if (m_cmd & SPI_TX_ONLY) {
if (geni_spi_handle_tx(mas))
writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
}
spin_unlock_irq(&mas->lock);
}
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);
if (spi_geni_is_abort_still_pending(mas))
return -EBUSY;
/* Terminate and return success for 0 byte length transfer */
if (!xfer->len)
return 0;
if (mas->cur_xfer_mode == GENI_SE_FIFO) {
setup_fifo_xfer(xfer, mas, slv->mode, spi);
return 1;
}
return setup_gsi_xfer(xfer, mas, slv, spi);
}
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;
m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
if (!m_irq)
return IRQ_NONE;
if (m_irq & (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |
M_RX_FIFO_RD_ERR_EN | M_RX_FIFO_WR_ERR_EN |
M_TX_FIFO_RD_ERR_EN | M_TX_FIFO_WR_ERR_EN))
dev_warn(mas->dev, "Unexpected IRQ err status %#010x\n", m_irq);
spin_lock(&mas->lock);
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_xfer) {
spi_finalize_current_transfer(spi);
mas->cur_xfer = NULL;
/*
* 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);
} else {
complete(&mas->cs_done);
}
}
if (m_irq & M_CMD_CANCEL_EN)
complete(&mas->cancel_done);
if (m_irq & M_CMD_ABORT_EN)
complete(&mas->abort_done);
/*
* It's safe or a good idea to Ack all of our interrupts at the end
* of the function. Specifically:
* - M_CMD_DONE_EN / M_RX_FIFO_LAST_EN: Edge triggered interrupts and
* clearing Acks. Clearing at the end relies on nobody else having
* started a new transfer yet or else we could be clearing _their_
* done bit, but everyone grabs the spinlock before starting a new
* transfer.
* - M_RX_FIFO_WATERMARK_EN / M_TX_FIFO_WATERMARK_EN: These appear
* to be "latched level" interrupts so it's important to clear them
* _after_ you've handled the condition and always safe to do so
* since they'll re-assert if they're still happening.
*/
writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
spin_unlock(&mas->lock);
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;
ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
if (ret)
return dev_err_probe(dev, ret, "could not set DMA mask\n");
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 = devm_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;
ret = devm_pm_opp_set_clkname(&pdev->dev, "se");
if (ret)
return ret;
/* OPP table is optional */
ret = devm_pm_opp_of_add_table(&pdev->dev);
if (ret && ret != -ENODEV) {
dev_err(&pdev->dev, "invalid OPP table in device tree\n");
return ret;
}
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->can_dma = geni_can_dma;
spi->dma_map_dev = dev->parent;
spi->auto_runtime_pm = true;
spi->handle_err = spi_geni_handle_err;
spi->use_gpio_descriptors = true;
init_completion(&mas->cs_done);
init_completion(&mas->cancel_done);
init_completion(&mas->abort_done);
spin_lock_init(&mas->lock);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
pm_runtime_enable(dev);
ret = geni_icc_get(&mas->se, NULL);
if (ret)
goto spi_geni_probe_runtime_disable;
/* Set the bus quota to a reasonable value for register access */
mas->se.icc_paths[GENI_TO_CORE].avg_bw = Bps_to_icc(CORE_2X_50_MHZ);
mas->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
ret = geni_icc_set_bw(&mas->se);
if (ret)
goto spi_geni_probe_runtime_disable;
ret = spi_geni_init(mas);
if (ret)
goto spi_geni_probe_runtime_disable;
/*
* check the mode supported and set_cs for fifo mode only
* for dma (gsi) mode, the gsi will set cs based on params passed in
* TRE
*/
if (mas->cur_xfer_mode == GENI_SE_FIFO)
spi->set_cs = spi_geni_set_cs;
ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);
if (ret)
goto spi_geni_release_dma;
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_release_dma:
spi_geni_release_dma_chan(mas);
spi_geni_probe_runtime_disable:
pm_runtime_disable(dev);
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);
spi_geni_release_dma_chan(mas);
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);
int ret;
/* Drop the performance state vote */
dev_pm_opp_set_rate(dev, 0);
ret = geni_se_resources_off(&mas->se);
if (ret)
return ret;
return geni_icc_disable(&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);
int ret;
ret = geni_icc_enable(&mas->se);
if (ret)
return ret;
ret = geni_se_resources_on(&mas->se);
if (ret)
return ret;
return dev_pm_opp_set_rate(mas->dev, mas->cur_sclk_hz);
}
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");