6.1-stable review patch. If anyone has any objections, please let me know.
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From: Tudor Ambarus tudor.ambarus@microchip.com
[ Upstream commit 684a47847ae639689e7b823251975348a8e5434f ]
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 Link: https://lore.kernel.org/r/20221117105249.115649-4-tudor.ambarus@microchip.co... Signed-off-by: Mark Brown broonie@kernel.org Stable-dep-of: fc70d643a2f6 ("spi: atmel: Fix clock issue when using devices with different polarities") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index dfce0f7d4c640..f1ed2863a183e 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3623,6 +3623,37 @@ 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 @@ -3719,6 +3750,12 @@ 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) {