[PATCH v4 2/2] spi: stm32_qspi: Add transfer_one_message() spi callback
patrice.chotard at foss.st.com
patrice.chotard at foss.st.com
Tue Aug 23 00:58:50 PDT 2022
From: Patrice Chotard <patrice.chotard at foss.st.com>
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 at foss.st.com>
---
v4: _ remove useless cleanup() callback.
v3: _ add cleanup() callback.
_ rework the trigger to enable dual flash mode QSPI block feature:
_ spi-tx-bus-width and spi-rx-bus-width must be set to 8.
_ cs-gpios property must be populated.
v2: _ use parallel-memories property
_ set auto_runtime_pm to true
_ remove pm_runtime_*() usage in transfer_one_message() callback
drivers/spi/spi-stm32-qspi.c | 118 ++++++++++++++++++++++++++++++++---
1 file changed, 109 insertions(+), 9 deletions(-)
diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c
index f3fe92300639..92459daca95f 100644
--- a/drivers/spi/spi-stm32-qspi.c
+++ b/drivers/spi/spi-stm32-qspi.c
@@ -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;
--
2.25.1
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