Import the spi_controller set_cs_timing() hook to make it easier to port
Linux spi drivers.
Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
Changelog:
v2:
- add spi_set_cs_timing()
drivers/spi/spi.c | 20 ++++++++++++++++++++
include/spi/spi.h | 12 ++++++++++++
2 files changed, 32 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 78569301776f..425c35759045 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -34,6 +34,22 @@ struct boardinfo {
static LIST_HEAD(board_list);
static LIST_HEAD(spi_controller_list);
+/**
+ * spi_set_cs_timing - configure CS setup, hold, and inactive delays
+ * @spi: the device that requires specific CS timing configuration
+ *
+ * Return: zero on success, else a negative error code.
+ */
+static int spi_set_cs_timing(struct spi_device *spi)
+{
+ int status = 0;
+
+ if (spi->controller->set_cs_timing && !spi->cs_gpiod)
+ status = spi->controller->set_cs_timing(spi);
+
+ return status;
+}
+
/**
* spi_new_device - instantiate one new SPI device
* @master: Controller to which device is connected
@@ -101,6 +117,10 @@ struct spi_device *spi_new_device(struct spi_controller *ctrl,
goto fail;
}
+ status = spi_set_cs_timing(proxy);
+ if (status)
+ goto fail;
+
status = register_device(&proxy->dev);
if (status)
goto fail;
diff --git a/include/spi/spi.h b/include/spi/spi.h
index a8bbf55e0a5a..106cca664068 100644
--- a/include/spi/spi.h
+++ b/include/spi/spi.h
@@ -179,6 +179,9 @@ static inline void spi_set_ctldata(struct spi_device *spi, void *state)
* must fail if an unrecognized or unsupported mode is requested.
* It's always safe to call this unless transfers are pending on
* the device whose settings are being modified.
+ * @set_cs_timing: optional hook for SPI devices to request SPI master
+ * controller for configuring specific CS setup time, hold time and inactive
+ * delay interms of clock counts
* @transfer: adds a message to the controller's transfer queue.
* @cleanup: frees controller-specific state
* @cs_gpiods: Array of GPIO descriptors to use as chip select lines; one per CS
@@ -249,6 +252,15 @@ struct spi_controller {
/* setup mode and clock, etc (spi driver may call many times) */
int (*setup)(struct spi_device *spi);
+ /*
+ * set_cs_timing() method is for SPI controllers that supports
+ * configuring CS timing.
+ *
+ * This hook allows SPI client drivers to request SPI controllers
+ * to configure specific CS timing through spi_set_cs_timing().
+ */
+ int (*set_cs_timing)(struct spi_device *spi);
+
/* bidirectional bulk transfers
*
* + The transfer() method may not sleep; its main role is
--
2.39.5
