[PATCH V2] spi: add power control when set_cs

[PATCH V2] spi: add power control when set_cs

[Luhua Xu]

From: "Luhua Xu" <luhua.xu@mediatek.com>

As to set_cs takes effect immediately, power spi
is needed when setup spi.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Luhua Xu <luhua.xu@mediatek.com>
---
V2:
- move set_cs PM control from .set_cs callback in
  vendor driver to spi_setup in spi framework.


 drivers/spi/spi.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index f9502db..19007e0 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -3091,7 +3091,20 @@ int spi_setup(struct spi_device *spi)
 	if (spi->controller->setup)
 		status = spi->controller->setup(spi);
 
-	spi_set_cs(spi, false);
+	if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
+		status = pm_runtime_get_sync(spi->controller->dev.parent);
+		if (status < 0) {
+			pm_runtime_put_noidle(spi->controller->dev.parent);
+			dev_err(&spi->controller->dev, "Failed to power device: %d\n",
+				status);
+			return status;
+		}
+		spi_set_cs(spi, false);
+		pm_runtime_mark_last_busy(spi->controller->dev.parent);
+		pm_runtime_put_autosuspend(spi->controller->dev.parent);
+	} else {
+		spi_set_cs(spi, false);
+	}
 
 	if (spi->rt && !spi->controller->rt) {
 		spi->controller->rt = true;
-- 
2.6.4

Applied "spi: add power control when set_cs" to the spi tree

[Mark Brown]

The patch

   spi: add power control when set_cs

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.5

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

From d948e6ca189985495a21cd622c31e30e72b6b688 Mon Sep 17 00:00:00 2001
From: Luhua Xu <luhua.xu@mediatek.com>
Date: Wed, 30 Oct 2019 17:03:54 +0800
Subject: [PATCH] spi: add power control when set_cs

As to set_cs takes effect immediately, power spi
is needed when setup spi.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Luhua Xu <luhua.xu@mediatek.com>
Link: https://lore.kernel.org/r/1572426234-30019-1-git-send-email-luhua.xu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 5ba19ef809c2..294d0038eea6 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -3261,7 +3261,20 @@ int spi_setup(struct spi_device *spi)
 	if (spi->controller->setup)
 		status = spi->controller->setup(spi);
 
-	spi_set_cs(spi, false);
+	if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
+		status = pm_runtime_get_sync(spi->controller->dev.parent);
+		if (status < 0) {
+			pm_runtime_put_noidle(spi->controller->dev.parent);
+			dev_err(&spi->controller->dev, "Failed to power device: %d\n",
+				status);
+			return status;
+		}
+		spi_set_cs(spi, false);
+		pm_runtime_mark_last_busy(spi->controller->dev.parent);
+		pm_runtime_put_autosuspend(spi->controller->dev.parent);
+	} else {
+		spi_set_cs(spi, false);
+	}
 
 	if (spi->rt && !spi->controller->rt) {
 		spi->controller->rt = true;
-- 
2.20.1

Re: Applied "spi: add power control when set_cs" to the spi tree

[Tony Lindgren]

Hi,

* Mark Brown <broonie@kernel.org> [191031 13:24]:
> The patch
> 
>    spi: add power control when set_cs
> 
> has been applied to the spi tree at
> 
>    https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-5.5

This patch causes a regression for many SPI devices as they
assume spi_setup() return 0 on success and not a positive value.

I've sent a fix for this as:

spi: Fix regression to return zero on success instead of positive value

Regards,

Tony