[PATCH v4 1/1] mfd: intel-lpss: save register context on suspend

[PATCH v4 1/1] mfd: intel-lpss: save register context on suspend

[Andy Shevchenko]

From: Heikki Krogerus <heikki.krogerus@linux.intel.com>

All configurations are lost and the registers will have
default values when the hardware is suspended and resumed,
so saving the private register space context on suspend, and
restoring it on resume.

Fixes: 4b45efe85263 (mfd: Add support for Intel Sunrisepoint LPSS devices)
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 drivers/mfd/intel-lpss.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
index 1bbbe87..807a3e3 100644
--- a/drivers/mfd/intel-lpss.c
+++ b/drivers/mfd/intel-lpss.c
@@ -34,6 +34,7 @@
 #define LPSS_DEV_SIZE		0x200
 #define LPSS_PRIV_OFFSET	0x200
 #define LPSS_PRIV_SIZE		0x100
+#define LPSS_PRIV_REG_COUNT	(LPSS_PRIV_SIZE / 4)
 #define LPSS_IDMA64_OFFSET	0x800
 #define LPSS_IDMA64_SIZE	0x800
 
@@ -76,6 +77,7 @@ struct intel_lpss {
 	struct mfd_cell *cell;
 	struct device *dev;
 	void __iomem *priv;
+	u32 priv_ctx[LPSS_PRIV_REG_COUNT];
 	int devid;
 	u32 caps;
 	u32 active_ltr;
@@ -493,6 +495,16 @@ EXPORT_SYMBOL_GPL(intel_lpss_prepare);
 
 int intel_lpss_suspend(struct device *dev)
 {
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+	unsigned int i;
+
+	/* Save device context */
+	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
+		lpss->priv_ctx[i] = readl(lpss->priv + i * 4);
+
+	/* Put the device into reset state */
+	writel(0, lpss->priv + LPSS_PRIV_RESETS);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(intel_lpss_suspend);
@@ -500,8 +512,13 @@ EXPORT_SYMBOL_GPL(intel_lpss_suspend);
 int intel_lpss_resume(struct device *dev)
 {
 	struct intel_lpss *lpss = dev_get_drvdata(dev);
+	unsigned int i;
 
-	intel_lpss_init_dev(lpss);
+	intel_lpss_deassert_reset(lpss);
+
+	/* Restore device context */
+	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
+		writel(lpss->priv_ctx[i], lpss->priv + i * 4);
 
 	return 0;
 }
-- 
2.8.0.rc3

Re: [PATCH v4 1/1] mfd: intel-lpss: save register context on suspend

[Lee Jones]

On Mon, 18 Apr 2016, Andy Shevchenko wrote:

> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> 
> All configurations are lost and the registers will have
> default values when the hardware is suspended and resumed,
> so saving the private register space context on suspend, and
> restoring it on resume.
> 
> Fixes: 4b45efe85263 (mfd: Add support for Intel Sunrisepoint LPSS devices)
> Cc: stable@vger.kernel.org # v4.3+
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> ---

You're missing a changelog.  I had to go and look at previous
submissions to catch up on the history.  Please make sure you provide
changelogs for >v1 submissions.

>  drivers/mfd/intel-lpss.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)

Applied, thanks.

> diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
> index 1bbbe87..807a3e3 100644
> --- a/drivers/mfd/intel-lpss.c
> +++ b/drivers/mfd/intel-lpss.c
> @@ -34,6 +34,7 @@
>  #define LPSS_DEV_SIZE		0x200
>  #define LPSS_PRIV_OFFSET	0x200
>  #define LPSS_PRIV_SIZE		0x100
> +#define LPSS_PRIV_REG_COUNT	(LPSS_PRIV_SIZE / 4)
>  #define LPSS_IDMA64_OFFSET	0x800
>  #define LPSS_IDMA64_SIZE	0x800
>  
> @@ -76,6 +77,7 @@ struct intel_lpss {
>  	struct mfd_cell *cell;
>  	struct device *dev;
>  	void __iomem *priv;
> +	u32 priv_ctx[LPSS_PRIV_REG_COUNT];
>  	int devid;
>  	u32 caps;
>  	u32 active_ltr;
> @@ -493,6 +495,16 @@ EXPORT_SYMBOL_GPL(intel_lpss_prepare);
>  
>  int intel_lpss_suspend(struct device *dev)
>  {
> +	struct intel_lpss *lpss = dev_get_drvdata(dev);
> +	unsigned int i;
> +
> +	/* Save device context */
> +	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
> +		lpss->priv_ctx[i] = readl(lpss->priv + i * 4);
> +
> +	/* Put the device into reset state */
> +	writel(0, lpss->priv + LPSS_PRIV_RESETS);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(intel_lpss_suspend);
> @@ -500,8 +512,13 @@ EXPORT_SYMBOL_GPL(intel_lpss_suspend);
>  int intel_lpss_resume(struct device *dev)
>  {
>  	struct intel_lpss *lpss = dev_get_drvdata(dev);
> +	unsigned int i;
>  
> -	intel_lpss_init_dev(lpss);
> +	intel_lpss_deassert_reset(lpss);
> +
> +	/* Restore device context */
> +	for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
> +		writel(lpss->priv_ctx[i], lpss->priv + i * 4);
>  
>  	return 0;
>  }

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v4 1/1] mfd: intel-lpss: save register context on suspend

[Heikki Krogerus]

Hi Lee,

On Mon, Apr 25, 2016 at 12:41:28PM +0100, Lee Jones wrote:
> On Mon, 18 Apr 2016, Andy Shevchenko wrote:
> 
> > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > 
> > All configurations are lost and the registers will have
> > default values when the hardware is suspended and resumed,
> > so saving the private register space context on suspend, and
> > restoring it on resume.
> > 
> > Fixes: 4b45efe85263 (mfd: Add support for Intel Sunrisepoint LPSS devices)
> > Cc: stable@vger.kernel.org # v4.3+
> > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > ---
> 
> You're missing a changelog.  I had to go and look at previous
> submissions to catch up on the history.  Please make sure you provide
> changelogs for >v1 submissions.
> 
> >  drivers/mfd/intel-lpss.c | 19 ++++++++++++++++++-
> >  1 file changed, 18 insertions(+), 1 deletion(-)
> 
> Applied, thanks.

This is still not in your tree?


Thanks,

-- 
heikki

Re: [PATCH v4 1/1] mfd: intel-lpss: save register context on suspend

[Lee Jones]

On Mon, 02 May 2016, Heikki Krogerus wrote:

> Hi Lee,
> 
> On Mon, Apr 25, 2016 at 12:41:28PM +0100, Lee Jones wrote:
> > On Mon, 18 Apr 2016, Andy Shevchenko wrote:
> > 
> > > From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > 
> > > All configurations are lost and the registers will have
> > > default values when the hardware is suspended and resumed,
> > > so saving the private register space context on suspend, and
> > > restoring it on resume.
> > > 
> > > Fixes: 4b45efe85263 (mfd: Add support for Intel Sunrisepoint LPSS devices)
> > > Cc: stable@vger.kernel.org # v4.3+
> > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > ---
> > 
> > You're missing a changelog.  I had to go and look at previous
> > submissions to catch up on the history.  Please make sure you provide
> > changelogs for >v1 submissions.
> > 
> > >  drivers/mfd/intel-lpss.c | 19 ++++++++++++++++++-
> > >  1 file changed, 18 insertions(+), 1 deletion(-)
> > 
> > Applied, thanks.
> 
> This is still not in your tree?

It's applied to my local tree.  Will likely push publicly today.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog