@@ -3621,6 +3621,37 @@ static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
return 0;
}
+/**
+ * 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)
+{
+ struct device *parent = spi->controller->dev.parent;
+ int status = 0;
+
+ if (spi->controller->set_cs_timing && !spi->cs_gpiod) {
+ if (spi->controller->auto_runtime_pm) {
+ status = pm_runtime_get_sync(parent);
+ if (status < 0) {
+ pm_runtime_put_noidle(parent);
+ dev_err(&spi->controller->dev, "Failed to power device: %d\n",
+ status);
+ return status;
+ }
+
+ status = spi->controller->set_cs_timing(spi);
+ pm_runtime_mark_last_busy(parent);
+ pm_runtime_put_autosuspend(parent);
+ } else {
+ status = spi->controller->set_cs_timing(spi);
+ }
+ }
+ return status;
+}
+
/**
* spi_setup - setup SPI mode and clock rate
* @spi: the device whose settings are being modified
@@ -3717,6 +3748,12 @@ int spi_setup(struct spi_device *spi)
}
}
+ status = spi_set_cs_timing(spi);
+ if (status) {
+ mutex_unlock(&spi->controller->io_mutex);
+ return status;
+ }
+
if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
status = pm_runtime_resume_and_get(spi->controller->dev.parent);
if (status < 0) {
commit 4ccf359849ce ("spi: remove spi_set_cs_timing()"), removed the method as noboby used it. Nobody used it probably because some SPI controllers use some default large cs-setup time that covers the usual cs-setup time required by the spi devices. There are though SPI controllers that have a smaller granularity for the cs-setup time and their default value can't fulfill the spi device requirements. That's the case for the at91 QSPI IPs where the default cs-setup time is half of the QSPI clock period. This was observed when using an sst26vf064b SPI NOR flash which needs a spi-cs-setup-ns = <7>; in order to be operated close to its maximum 104 MHz frequency. Call spi_set_cs_timing() in spi_setup() just before calling spi_set_cs(), as the latter needs the CS timings already set. If spi->controller->set_cs_timing is not set, the method will return 0. There's no functional impact expected for the existing drivers. Even if the spi-mt65xx.c and spi-tegra114.c drivers set the set_cs_timing method, there's no user for them as of now. The only tested user of this support will be a SPI NOR flash that comunicates with the Atmel QSPI controller for which the support follows in the next patches. One will notice that this support is a bit different from the one that was removed in commit 4ccf359849ce ("spi: remove spi_set_cs_timing()"), because this patch adapts to the changes done after the removal: the move of the cs delays to the spi device, the retirement of the lelgacy GPIO handling. The mutex handling was removed from spi_set_cs_timing() because we now always call spi_set_cs_timing() in spi_setup(), which already handles the spi->controller->io_mutex, so use the mutex handling from spi_setup(). Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> --- drivers/spi/spi.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)