spi: stm32-qspi: Add pm_runtime support

spi: stm32-qspi: Add pm_runtime support

[patrice.chotard]

From: Patrice Chotard <patrice.chotard@st.com>

By default, STM32_AUTOSUSPEND_DELAY is set to -1 which has for
effect to prevent runtime suspends.
Runtime suspends can be activated by setting autosuspend_delay_ms using
sysfs entry :
echo {delay_in_ms} > /sys/devices/platform/soc/58003000.spi/power/autosusp
end_delay_ms)

Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
---
 drivers/spi/spi-stm32-qspi.c | 57 +++++++++++++++++++++++++++++++++---
 1 file changed, 53 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c
index d066f5144c3e..2f2ea2c42d6e 100644
--- a/drivers/spi/spi-stm32-qspi.c
+++ b/drivers/spi/spi-stm32-qspi.c
@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
 #include <linux/sizes.h>
@@ -87,6 +88,7 @@
 #define STM32_BUSY_TIMEOUT_US 100000
 #define STM32_ABT_TIMEOUT_US 100000
 #define STM32_COMP_TIMEOUT_MS 1000
+#define STM32_AUTOSUSPEND_DELAY -1
 
 struct stm32_qspi_flash {
 	struct stm32_qspi *qspi;
@@ -431,10 +433,17 @@ static int stm32_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
 	int ret;
 
+	ret = pm_runtime_get_sync(qspi->dev);
+	if (ret < 0)
+		return ret;
+
 	mutex_lock(&qspi->lock);
 	ret = stm32_qspi_send(mem, op);
 	mutex_unlock(&qspi->lock);
 
+	pm_runtime_mark_last_busy(qspi->dev);
+	pm_runtime_put_autosuspend(qspi->dev);
+
 	return ret;
 }
 
@@ -444,6 +453,7 @@ static int stm32_qspi_setup(struct spi_device *spi)
 	struct stm32_qspi *qspi = spi_controller_get_devdata(ctrl);
 	struct stm32_qspi_flash *flash;
 	u32 presc;
+	int ret;
 
 	if (ctrl->busy)
 		return -EBUSY;
@@ -451,6 +461,10 @@ static int stm32_qspi_setup(struct spi_device *spi)
 	if (!spi->max_speed_hz)
 		return -EINVAL;
 
+	ret = pm_runtime_get_sync(qspi->dev);
+	if (ret < 0)
+		return ret;
+
 	presc = DIV_ROUND_UP(qspi->clk_rate, spi->max_speed_hz) - 1;
 
 	flash = &qspi->flash[spi->chip_select];
@@ -467,6 +481,9 @@ static int stm32_qspi_setup(struct spi_device *spi)
 	writel_relaxed(qspi->dcr_reg, qspi->io_base + QSPI_DCR);
 	mutex_unlock(&qspi->lock);
 
+	pm_runtime_mark_last_busy(qspi->dev);
+	pm_runtime_put_autosuspend(qspi->dev);
+
 	return 0;
 }
 
@@ -643,9 +660,20 @@ static int stm32_qspi_probe(struct platform_device *pdev)
 	ctrl->num_chipselect = STM32_QSPI_MAX_NORCHIP;
 	ctrl->dev.of_node = dev->of_node;
 
+	pm_runtime_set_autosuspend_delay(dev, STM32_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+	pm_runtime_get_noresume(dev);
+
 	ret = devm_spi_register_master(dev, ctrl);
-	if (!ret)
-		return 0;
+	if (ret)
+		goto err_qspi_release;
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
 
 err_qspi_release:
 	stm32_qspi_release(qspi);
@@ -660,14 +688,28 @@ static int stm32_qspi_remove(struct platform_device *pdev)
 	struct stm32_qspi *qspi = platform_get_drvdata(pdev);
 
 	stm32_qspi_release(qspi);
+
 	return 0;
 }
 
-static int __maybe_unused stm32_qspi_suspend(struct device *dev)
+static int __maybe_unused stm32_qspi_runtime_suspend(struct device *dev)
 {
 	struct stm32_qspi *qspi = dev_get_drvdata(dev);
 
 	clk_disable_unprepare(qspi->clk);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_qspi_runtime_resume(struct device *dev)
+{
+	struct stm32_qspi *qspi = dev_get_drvdata(dev);
+
+	return clk_prepare_enable(qspi->clk);
+}
+
+static int __maybe_unused stm32_qspi_suspend(struct device *dev)
+{
 	pinctrl_pm_select_sleep_state(dev);
 
 	return 0;
@@ -683,10 +725,17 @@ static int __maybe_unused stm32_qspi_resume(struct device *dev)
 	writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR);
 	writel_relaxed(qspi->dcr_reg, qspi->io_base + QSPI_DCR);
 
+	pm_runtime_mark_last_busy(qspi->dev);
+	pm_runtime_put_autosuspend(qspi->dev);
+
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(stm32_qspi_pm_ops, stm32_qspi_suspend, stm32_qspi_resume);
+static const struct dev_pm_ops stm32_qspi_pm_ops = {
+	SET_RUNTIME_PM_OPS(stm32_qspi_runtime_suspend,
+			   stm32_qspi_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(stm32_qspi_suspend, stm32_qspi_resume)
+};
 
 static const struct of_device_id stm32_qspi_match[] = {
 	{.compatible = "st,stm32f469-qspi"},
-- 
2.17.1

Re: spi: stm32-qspi: Add pm_runtime support

[Mark Brown]

On Fri, 17 Apr 2020 14:12:41 +0200, patrice.chotard@st.com wrote:
> From: Patrice Chotard <patrice.chotard@st.com>
> 
> By default, STM32_AUTOSUSPEND_DELAY is set to -1 which has for
> effect to prevent runtime suspends.
> Runtime suspends can be activated by setting autosuspend_delay_ms using
> sysfs entry :
> echo {delay_in_ms} > /sys/devices/platform/soc/58003000.spi/power/autosusp
> end_delay_ms)
> 
> [...]

Applied, thanks!

[1/1] spi: stm32-qspi: Add pm_runtime support
      commit: 9d282c17b023a97516a63255ce7f7ee65c39bec1

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark