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spi: stm32_qspi: Add transfer_one_message() spi callback

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Add transfer_one_message() spi callback in order to use the QSPI interface
as a communication channel using up to 8 qspi lines (QSPI configured
in dual flash mode).
To enable this mode, both spi-rx-bus-width and spi-tx-bus-width must be
set to 8 and cs-qpios must be populated.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20220823075850.575043-3-patrice.chotard@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Patrice Chotard 2022-08-23 09:58:50 +02:00 committed by Mark Brown
parent 1d895be13a
commit a557fca630
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
1 changed files with 109 additions and 9 deletions
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118
drivers/spi/spi-stm32-qspi.c
View file

@ -15,6 +15,7 @@
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
@ -355,10 +356,10 @@ static int stm32_qspi_get_mode(u8 buswidth)
return buswidth;
}
static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op)
static int stm32_qspi_send(struct spi_device *spi, 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];
struct stm32_qspi *qspi = spi_controller_get_devdata(spi->master);
struct stm32_qspi_flash *flash = &qspi->flash[spi->chip_select];
u32 ccr, cr;
int timeout, err = 0, err_poll_status = 0;
@ -465,7 +466,7 @@ static int stm32_qspi_poll_status(struct spi_mem *mem, const struct spi_mem_op *
qspi->fmode = CCR_FMODE_APM;
qspi->status_timeout = timeout_ms;
ret = stm32_qspi_send(mem, op);
ret = stm32_qspi_send(mem->spi, op);
mutex_unlock(&qspi->lock);
pm_runtime_mark_last_busy(qspi->dev);
@ -489,7 +490,7 @@ static int stm32_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
else
qspi->fmode = CCR_FMODE_INDW;
ret = stm32_qspi_send(mem, op);
ret = stm32_qspi_send(mem->spi, op);
mutex_unlock(&qspi->lock);
pm_runtime_mark_last_busy(qspi->dev);
@ -545,7 +546,7 @@ static ssize_t stm32_qspi_dirmap_read(struct spi_mem_dirmap_desc *desc,
else
qspi->fmode = CCR_FMODE_INDR;
ret = stm32_qspi_send(desc->mem, &op);
ret = stm32_qspi_send(desc->mem->spi, &op);
mutex_unlock(&qspi->lock);
pm_runtime_mark_last_busy(qspi->dev);
@ -554,12 +555,87 @@ static ssize_t stm32_qspi_dirmap_read(struct spi_mem_dirmap_desc *desc,
return ret ?: len;
}
static int stm32_qspi_transfer_one_message(struct spi_controller *ctrl,
struct spi_message *msg)
{
struct stm32_qspi *qspi = spi_controller_get_devdata(ctrl);
struct spi_transfer *transfer;
struct spi_device *spi = msg->spi;
struct spi_mem_op op;
int ret;
if (!spi->cs_gpiod)
return -EOPNOTSUPP;
mutex_lock(&qspi->lock);
gpiod_set_value_cansleep(spi->cs_gpiod, true);
list_for_each_entry(transfer, &msg->transfers, transfer_list) {
u8 dummy_bytes = 0;
memset(&op, 0, sizeof(op));
dev_dbg(qspi->dev, "tx_buf:%p tx_nbits:%d rx_buf:%p rx_nbits:%d len:%d dummy_data:%d\n",
transfer->tx_buf, transfer->tx_nbits,
transfer->rx_buf, transfer->rx_nbits,
transfer->len, transfer->dummy_data);
/*
* QSPI hardware supports dummy bytes transfer.
* If current transfer is dummy byte, merge it with the next
* transfer in order to take into account QSPI block constraint
*/
if (transfer->dummy_data) {
op.dummy.buswidth = transfer->tx_nbits;
op.dummy.nbytes = transfer->len;
dummy_bytes = transfer->len;
/* if happens, means that message is not correctly built */
if (list_is_last(&transfer->transfer_list, &msg->transfers))
goto end_of_transfer;
transfer = list_next_entry(transfer, transfer_list);
}
op.data.nbytes = transfer->len;
if (transfer->rx_buf) {
qspi->fmode = CCR_FMODE_INDR;
op.data.buswidth = transfer->rx_nbits;
op.data.dir = SPI_MEM_DATA_IN;
op.data.buf.in = transfer->rx_buf;
} else {
qspi->fmode = CCR_FMODE_INDW;
op.data.buswidth = transfer->tx_nbits;
op.data.dir = SPI_MEM_DATA_OUT;
op.data.buf.out = transfer->tx_buf;
}
ret = stm32_qspi_send(spi, &op);
if (ret)
goto end_of_transfer;
msg->actual_length += transfer->len + dummy_bytes;
}
end_of_transfer:
gpiod_set_value_cansleep(spi->cs_gpiod, false);
mutex_unlock(&qspi->lock);
msg->status = ret;
spi_finalize_current_message(ctrl);
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 presc;
u32 presc, mode;
int ret;
if (ctrl->busy)
@ -568,6 +644,16 @@ static int stm32_qspi_setup(struct spi_device *spi)
if (!spi->max_speed_hz)
return -EINVAL;
mode = spi->mode & (SPI_TX_OCTAL | SPI_RX_OCTAL);
if ((mode == SPI_TX_OCTAL || mode == SPI_RX_OCTAL) ||
((mode == (SPI_TX_OCTAL | SPI_RX_OCTAL)) &&
of_gpio_named_count(qspi->dev->of_node, "cs-gpios") == -ENOENT)) {
dev_err(qspi->dev, "spi-rx-bus-width\\/spi-tx-bus-width\\/cs-gpios\n");
dev_err(qspi->dev, "configuration not supported\n");
return -EINVAL;
}
ret = pm_runtime_resume_and_get(qspi->dev);
if (ret < 0)
return ret;
@ -580,6 +666,17 @@ static int stm32_qspi_setup(struct spi_device *spi)
mutex_lock(&qspi->lock);
qspi->cr_reg = CR_APMS | 3 << CR_FTHRES_SHIFT | CR_SSHIFT | CR_EN;
/*
* Dual flash mode is only enable in case SPI_TX_OCTAL and SPI_TX_OCTAL
* are both set in spi->mode and "cs-gpios" properties is found in DT
*/
if (((spi->mode & (SPI_TX_OCTAL | SPI_RX_OCTAL)) == (SPI_TX_OCTAL | SPI_RX_OCTAL)) &&
of_gpio_named_count(qspi->dev->of_node, "cs-gpios")) {
qspi->cr_reg |= CR_DFM;
dev_dbg(qspi->dev, "Dual flash mode enable");
}
writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR);
/* set dcr fsize to max address */
@ -741,11 +838,14 @@ static int stm32_qspi_probe(struct platform_device *pdev)
mutex_init(&qspi->lock);
ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD
| SPI_TX_DUAL | SPI_TX_QUAD;
ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD | SPI_TX_OCTAL
| SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_OCTAL;
ctrl->setup = stm32_qspi_setup;
ctrl->bus_num = -1;
ctrl->mem_ops = &stm32_qspi_mem_ops;
ctrl->use_gpio_descriptors = true;
ctrl->transfer_one_message = stm32_qspi_transfer_one_message;
ctrl->auto_runtime_pm = true;
ctrl->num_chipselect = STM32_QSPI_MAX_NORCHIP;
ctrl->dev.of_node = dev->of_node;