* Re: [PATCH] drm: fsl-dcu: enable PIXCLK on LS1021A
@ 2020-08-21 13:41 ` Stefan Agner
0 siblings, 0 replies; 10+ messages in thread
From: Stefan Agner @ 2020-08-21 13:41 UTC (permalink / raw)
To: Matthias Schiffer, sboyd, mturquette
Cc: David Airlie, Alison Wang, dri-devel, linux-kernel
Hi Matthias,
On 2020-08-20 12:58, Matthias Schiffer wrote:
> The PIXCLK needs to be enabled in SCFG before accessing the DCU on LS1021A,
> or the access will hang.
Hm, this seems a rather ad-hoc access to SCFG from the DCU. We do
support a pixel clock in the device tree bindings of fsl-dcu, so ideally
we should enable the pixel clock through the clock framework.
On the other hand, I guess that would mean adding a clock driver to flip
a single bit, which seems a bit excessive too.
I'd like a second opinion on that. Adding clk framework maintainers.
--
Stefan
>
> Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> ---
> drivers/gpu/drm/fsl-dcu/Kconfig | 1 +
> drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 25 +++++++++++++++++++++++
> drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 3 +++
> 3 files changed, 29 insertions(+)
>
> diff --git a/drivers/gpu/drm/fsl-dcu/Kconfig b/drivers/gpu/drm/fsl-dcu/Kconfig
> index d7dd8ba90e3a..9e5a35e7c00c 100644
> --- a/drivers/gpu/drm/fsl-dcu/Kconfig
> +++ b/drivers/gpu/drm/fsl-dcu/Kconfig
> @@ -8,6 +8,7 @@ config DRM_FSL_DCU
> select DRM_PANEL
> select REGMAP_MMIO
> select VIDEOMODE_HELPERS
> + select MFD_SYSCON if SOC_LS1021A
> help
> Choose this option if you have an Freescale DCU chipset.
> If M is selected the module will be called fsl-dcu-drm.
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> index abbc1ddbf27f..8a7556655581 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> @@ -51,6 +51,23 @@ static const struct regmap_config fsl_dcu_regmap_config = {
> .volatile_reg = fsl_dcu_drm_is_volatile_reg,
> };
>
> +static int fsl_dcu_scfg_config_ls1021a(struct device_node *np)
> +{
> + struct regmap *scfg;
> +
> + scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
> + if (IS_ERR(scfg))
> + return PTR_ERR(scfg);
> +
> + /*
> + * For simplicity, enable the PIXCLK unconditionally. It might
> + * be possible to disable the clock in PM or on unload as a future
> + * improvement.
> + */
> + return regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,
> + SCFG_PIXCLKCR_PXCEN);
> +}
> +
> static void fsl_dcu_irq_uninstall(struct drm_device *dev)
> {
> struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> @@ -70,6 +87,14 @@ static int fsl_dcu_load(struct drm_device *dev,
> unsigned long flags)
> return ret;
> }
>
> + if (of_device_is_compatible(fsl_dev->np, "fsl,ls1021a-dcu")) {
> + ret = fsl_dcu_scfg_config_ls1021a(fsl_dev->np);
> + if (ret < 0) {
> + dev_err(dev->dev, "failed to enable pixclk\n");
> + goto done;
> + }
> + }
> +
> ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
> if (ret < 0) {
> dev_err(dev->dev, "failed to initialize vblank\n");
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> index e2049a0e8a92..566396013c04 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> @@ -160,6 +160,9 @@
> #define FSL_DCU_ARGB4444 12
> #define FSL_DCU_YUV422 14
>
> +#define SCFG_PIXCLKCR 0x28
> +#define SCFG_PIXCLKCR_PXCEN BIT(31)
> +
> #define VF610_LAYER_REG_NUM 9
> #define LS1021A_LAYER_REG_NUM 10
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^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm: fsl-dcu: enable PIXCLK on LS1021A
2020-08-21 13:41 ` Stefan Agner
@ 2020-09-18 8:06 ` Matthias Schiffer
-1 siblings, 0 replies; 10+ messages in thread
From: Matthias Schiffer @ 2020-09-18 8:06 UTC (permalink / raw)
To: Stefan Agner, sboyd, mturquette
Cc: Alison Wang, David Airlie, Daniel Vetter, dri-devel, linux-kernel
On Fri, 2020-08-21 at 15:41 +0200, Stefan Agner wrote:
> Hi Matthias,
>
> On 2020-08-20 12:58, Matthias Schiffer wrote:
> > The PIXCLK needs to be enabled in SCFG before accessing the DCU on LS1021A,
> > or the access will hang.
>
> Hm, this seems a rather ad-hoc access to SCFG from the DCU. We do
> support a pixel clock in the device tree bindings of fsl-dcu, so ideally
> we should enable the pixel clock through the clock framework.
>
> On the other hand, I guess that would mean adding a clock driver to flip
> a single bit, which seems a bit excessive too.
>
> I'd like a second opinion on that. Adding clk framework maintainers.
>
> --
> Stefan
How do we proceed with this patch?
Kind regards,
Matthias
>
> >
> > Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> > ---
> > drivers/gpu/drm/fsl-dcu/Kconfig | 1 +
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 25 +++++++++++++++++++++++
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 3 +++
> > 3 files changed, 29 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/fsl-dcu/Kconfig b/drivers/gpu/drm/fsl-dcu/Kconfig
> > index d7dd8ba90e3a..9e5a35e7c00c 100644
> > --- a/drivers/gpu/drm/fsl-dcu/Kconfig
> > +++ b/drivers/gpu/drm/fsl-dcu/Kconfig
> > @@ -8,6 +8,7 @@ config DRM_FSL_DCU
> > select DRM_PANEL
> > select REGMAP_MMIO
> > select VIDEOMODE_HELPERS
> > + select MFD_SYSCON if SOC_LS1021A
> > help
> > Choose this option if you have an Freescale DCU chipset.
> > If M is selected the module will be called fsl-dcu-drm.
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > index abbc1ddbf27f..8a7556655581 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > @@ -51,6 +51,23 @@ static const struct regmap_config fsl_dcu_regmap_config = {
> > .volatile_reg = fsl_dcu_drm_is_volatile_reg,
> > };
> >
> > +static int fsl_dcu_scfg_config_ls1021a(struct device_node *np)
> > +{
> > + struct regmap *scfg;
> > +
> > + scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
> > + if (IS_ERR(scfg))
> > + return PTR_ERR(scfg);
> > +
> > + /*
> > + * For simplicity, enable the PIXCLK unconditionally. It might
> > + * be possible to disable the clock in PM or on unload as a future
> > + * improvement.
> > + */
> > + return regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,
> > + SCFG_PIXCLKCR_PXCEN);
> > +}
> > +
> > static void fsl_dcu_irq_uninstall(struct drm_device *dev)
> > {
> > struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> > @@ -70,6 +87,14 @@ static int fsl_dcu_load(struct drm_device *dev,
> > unsigned long flags)
> > return ret;
> > }
> >
> > + if (of_device_is_compatible(fsl_dev->np, "fsl,ls1021a-dcu")) {
> > + ret = fsl_dcu_scfg_config_ls1021a(fsl_dev->np);
> > + if (ret < 0) {
> > + dev_err(dev->dev, "failed to enable pixclk\n");
> > + goto done;
> > + }
> > + }
> > +
> > ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
> > if (ret < 0) {
> > dev_err(dev->dev, "failed to initialize vblank\n");
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > index e2049a0e8a92..566396013c04 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > @@ -160,6 +160,9 @@
> > #define FSL_DCU_ARGB4444 12
> > #define FSL_DCU_YUV422 14
> >
> > +#define SCFG_PIXCLKCR 0x28
> > +#define SCFG_PIXCLKCR_PXCEN BIT(31)
> > +
> > #define VF610_LAYER_REG_NUM 9
> > #define LS1021A_LAYER_REG_NUM 10
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm: fsl-dcu: enable PIXCLK on LS1021A
@ 2020-09-18 8:06 ` Matthias Schiffer
0 siblings, 0 replies; 10+ messages in thread
From: Matthias Schiffer @ 2020-09-18 8:06 UTC (permalink / raw)
To: Stefan Agner, sboyd, mturquette
Cc: David Airlie, Alison Wang, dri-devel, linux-kernel
On Fri, 2020-08-21 at 15:41 +0200, Stefan Agner wrote:
> Hi Matthias,
>
> On 2020-08-20 12:58, Matthias Schiffer wrote:
> > The PIXCLK needs to be enabled in SCFG before accessing the DCU on LS1021A,
> > or the access will hang.
>
> Hm, this seems a rather ad-hoc access to SCFG from the DCU. We do
> support a pixel clock in the device tree bindings of fsl-dcu, so ideally
> we should enable the pixel clock through the clock framework.
>
> On the other hand, I guess that would mean adding a clock driver to flip
> a single bit, which seems a bit excessive too.
>
> I'd like a second opinion on that. Adding clk framework maintainers.
>
> --
> Stefan
How do we proceed with this patch?
Kind regards,
Matthias
>
> >
> > Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> > ---
> > drivers/gpu/drm/fsl-dcu/Kconfig | 1 +
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 25 +++++++++++++++++++++++
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 3 +++
> > 3 files changed, 29 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/fsl-dcu/Kconfig b/drivers/gpu/drm/fsl-dcu/Kconfig
> > index d7dd8ba90e3a..9e5a35e7c00c 100644
> > --- a/drivers/gpu/drm/fsl-dcu/Kconfig
> > +++ b/drivers/gpu/drm/fsl-dcu/Kconfig
> > @@ -8,6 +8,7 @@ config DRM_FSL_DCU
> > select DRM_PANEL
> > select REGMAP_MMIO
> > select VIDEOMODE_HELPERS
> > + select MFD_SYSCON if SOC_LS1021A
> > help
> > Choose this option if you have an Freescale DCU chipset.
> > If M is selected the module will be called fsl-dcu-drm.
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > index abbc1ddbf27f..8a7556655581 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > @@ -51,6 +51,23 @@ static const struct regmap_config fsl_dcu_regmap_config = {
> > .volatile_reg = fsl_dcu_drm_is_volatile_reg,
> > };
> >
> > +static int fsl_dcu_scfg_config_ls1021a(struct device_node *np)
> > +{
> > + struct regmap *scfg;
> > +
> > + scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
> > + if (IS_ERR(scfg))
> > + return PTR_ERR(scfg);
> > +
> > + /*
> > + * For simplicity, enable the PIXCLK unconditionally. It might
> > + * be possible to disable the clock in PM or on unload as a future
> > + * improvement.
> > + */
> > + return regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,
> > + SCFG_PIXCLKCR_PXCEN);
> > +}
> > +
> > static void fsl_dcu_irq_uninstall(struct drm_device *dev)
> > {
> > struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> > @@ -70,6 +87,14 @@ static int fsl_dcu_load(struct drm_device *dev,
> > unsigned long flags)
> > return ret;
> > }
> >
> > + if (of_device_is_compatible(fsl_dev->np, "fsl,ls1021a-dcu")) {
> > + ret = fsl_dcu_scfg_config_ls1021a(fsl_dev->np);
> > + if (ret < 0) {
> > + dev_err(dev->dev, "failed to enable pixclk\n");
> > + goto done;
> > + }
> > + }
> > +
> > ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
> > if (ret < 0) {
> > dev_err(dev->dev, "failed to initialize vblank\n");
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > index e2049a0e8a92..566396013c04 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > @@ -160,6 +160,9 @@
> > #define FSL_DCU_ARGB4444 12
> > #define FSL_DCU_YUV422 14
> >
> > +#define SCFG_PIXCLKCR 0x28
> > +#define SCFG_PIXCLKCR_PXCEN BIT(31)
> > +
> > #define VF610_LAYER_REG_NUM 9
> > #define LS1021A_LAYER_REG_NUM 10
_______________________________________________
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https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] drm: fsl-dcu: enable PIXCLK on LS1021A
2020-08-21 13:41 ` Stefan Agner
@ 2021-09-16 12:50 ` Matthias Schiffer
-1 siblings, 0 replies; 10+ messages in thread
From: Matthias Schiffer @ 2021-09-16 12:50 UTC (permalink / raw)
To: Stefan Agner, sboyd, mturquette
Cc: Alison Wang, David Airlie, Daniel Vetter, dri-devel, linux-kernel
On Fri, 2020-08-21 at 15:41 +0200, Stefan Agner wrote:
> Hi Matthias,
>
> On 2020-08-20 12:58, Matthias Schiffer wrote:
> > The PIXCLK needs to be enabled in SCFG before accessing the DCU on LS1021A,
> > or the access will hang.
>
> Hm, this seems a rather ad-hoc access to SCFG from the DCU. We do
> support a pixel clock in the device tree bindings of fsl-dcu, so ideally
> we should enable the pixel clock through the clock framework.
>
> On the other hand, I guess that would mean adding a clock driver to flip
> a single bit, which seems a bit excessive too.
>
> I'd like a second opinion on that. Adding clk framework maintainers.
It's been a while, and nobody else has given their opinion. How should
we proceed with this patch?
Matthias
>
> --
> Stefan
>
> >
> > Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> > ---
> > drivers/gpu/drm/fsl-dcu/Kconfig | 1 +
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 25 +++++++++++++++++++++++
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 3 +++
> > 3 files changed, 29 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/fsl-dcu/Kconfig b/drivers/gpu/drm/fsl-dcu/Kconfig
> > index d7dd8ba90e3a..9e5a35e7c00c 100644
> > --- a/drivers/gpu/drm/fsl-dcu/Kconfig
> > +++ b/drivers/gpu/drm/fsl-dcu/Kconfig
> > @@ -8,6 +8,7 @@ config DRM_FSL_DCU
> > select DRM_PANEL
> > select REGMAP_MMIO
> > select VIDEOMODE_HELPERS
> > + select MFD_SYSCON if SOC_LS1021A
> > help
> > Choose this option if you have an Freescale DCU chipset.
> > If M is selected the module will be called fsl-dcu-drm.
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > index abbc1ddbf27f..8a7556655581 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > @@ -51,6 +51,23 @@ static const struct regmap_config fsl_dcu_regmap_config = {
> > .volatile_reg = fsl_dcu_drm_is_volatile_reg,
> > };
> >
> > +static int fsl_dcu_scfg_config_ls1021a(struct device_node *np)
> > +{
> > + struct regmap *scfg;
> > +
> > + scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
> > + if (IS_ERR(scfg))
> > + return PTR_ERR(scfg);
> > +
> > + /*
> > + * For simplicity, enable the PIXCLK unconditionally. It might
> > + * be possible to disable the clock in PM or on unload as a future
> > + * improvement.
> > + */
> > + return regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,
> > + SCFG_PIXCLKCR_PXCEN);
> > +}
> > +
> > static void fsl_dcu_irq_uninstall(struct drm_device *dev)
> > {
> > struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> > @@ -70,6 +87,14 @@ static int fsl_dcu_load(struct drm_device *dev,
> > unsigned long flags)
> > return ret;
> > }
> >
> > + if (of_device_is_compatible(fsl_dev->np, "fsl,ls1021a-dcu")) {
> > + ret = fsl_dcu_scfg_config_ls1021a(fsl_dev->np);
> > + if (ret < 0) {
> > + dev_err(dev->dev, "failed to enable pixclk\n");
> > + goto done;
> > + }
> > + }
> > +
> > ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
> > if (ret < 0) {
> > dev_err(dev->dev, "failed to initialize vblank\n");
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > index e2049a0e8a92..566396013c04 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > @@ -160,6 +160,9 @@
> > #define FSL_DCU_ARGB4444 12
> > #define FSL_DCU_YUV422 14
> >
> > +#define SCFG_PIXCLKCR 0x28
> > +#define SCFG_PIXCLKCR_PXCEN BIT(31)
> > +
> > #define VF610_LAYER_REG_NUM 9
> > #define LS1021A_LAYER_REG_NUM 10
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm: fsl-dcu: enable PIXCLK on LS1021A
@ 2021-09-16 12:50 ` Matthias Schiffer
0 siblings, 0 replies; 10+ messages in thread
From: Matthias Schiffer @ 2021-09-16 12:50 UTC (permalink / raw)
To: Stefan Agner, sboyd, mturquette
Cc: Alison Wang, David Airlie, Daniel Vetter, dri-devel, linux-kernel
On Fri, 2020-08-21 at 15:41 +0200, Stefan Agner wrote:
> Hi Matthias,
>
> On 2020-08-20 12:58, Matthias Schiffer wrote:
> > The PIXCLK needs to be enabled in SCFG before accessing the DCU on LS1021A,
> > or the access will hang.
>
> Hm, this seems a rather ad-hoc access to SCFG from the DCU. We do
> support a pixel clock in the device tree bindings of fsl-dcu, so ideally
> we should enable the pixel clock through the clock framework.
>
> On the other hand, I guess that would mean adding a clock driver to flip
> a single bit, which seems a bit excessive too.
>
> I'd like a second opinion on that. Adding clk framework maintainers.
It's been a while, and nobody else has given their opinion. How should
we proceed with this patch?
Matthias
>
> --
> Stefan
>
> >
> > Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> > ---
> > drivers/gpu/drm/fsl-dcu/Kconfig | 1 +
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 25 +++++++++++++++++++++++
> > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 3 +++
> > 3 files changed, 29 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/fsl-dcu/Kconfig b/drivers/gpu/drm/fsl-dcu/Kconfig
> > index d7dd8ba90e3a..9e5a35e7c00c 100644
> > --- a/drivers/gpu/drm/fsl-dcu/Kconfig
> > +++ b/drivers/gpu/drm/fsl-dcu/Kconfig
> > @@ -8,6 +8,7 @@ config DRM_FSL_DCU
> > select DRM_PANEL
> > select REGMAP_MMIO
> > select VIDEOMODE_HELPERS
> > + select MFD_SYSCON if SOC_LS1021A
> > help
> > Choose this option if you have an Freescale DCU chipset.
> > If M is selected the module will be called fsl-dcu-drm.
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > index abbc1ddbf27f..8a7556655581 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > @@ -51,6 +51,23 @@ static const struct regmap_config fsl_dcu_regmap_config = {
> > .volatile_reg = fsl_dcu_drm_is_volatile_reg,
> > };
> >
> > +static int fsl_dcu_scfg_config_ls1021a(struct device_node *np)
> > +{
> > + struct regmap *scfg;
> > +
> > + scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
> > + if (IS_ERR(scfg))
> > + return PTR_ERR(scfg);
> > +
> > + /*
> > + * For simplicity, enable the PIXCLK unconditionally. It might
> > + * be possible to disable the clock in PM or on unload as a future
> > + * improvement.
> > + */
> > + return regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,
> > + SCFG_PIXCLKCR_PXCEN);
> > +}
> > +
> > static void fsl_dcu_irq_uninstall(struct drm_device *dev)
> > {
> > struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> > @@ -70,6 +87,14 @@ static int fsl_dcu_load(struct drm_device *dev,
> > unsigned long flags)
> > return ret;
> > }
> >
> > + if (of_device_is_compatible(fsl_dev->np, "fsl,ls1021a-dcu")) {
> > + ret = fsl_dcu_scfg_config_ls1021a(fsl_dev->np);
> > + if (ret < 0) {
> > + dev_err(dev->dev, "failed to enable pixclk\n");
> > + goto done;
> > + }
> > + }
> > +
> > ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
> > if (ret < 0) {
> > dev_err(dev->dev, "failed to initialize vblank\n");
> > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > index e2049a0e8a92..566396013c04 100644
> > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > @@ -160,6 +160,9 @@
> > #define FSL_DCU_ARGB4444 12
> > #define FSL_DCU_YUV422 14
> >
> > +#define SCFG_PIXCLKCR 0x28
> > +#define SCFG_PIXCLKCR_PXCEN BIT(31)
> > +
> > #define VF610_LAYER_REG_NUM 9
> > #define LS1021A_LAYER_REG_NUM 10
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm: fsl-dcu: enable PIXCLK on LS1021A
2021-09-16 12:50 ` Matthias Schiffer
(?)
@ 2021-10-05 12:35 ` Matthias Schiffer
2021-10-05 13:45 ` Stefan Agner
-1 siblings, 1 reply; 10+ messages in thread
From: Matthias Schiffer @ 2021-10-05 12:35 UTC (permalink / raw)
To: Stefan Agner, sboyd, mturquette
Cc: Alison Wang, David Airlie, Daniel Vetter, dri-devel, linux-kernel
On Thu, 2021-09-16 at 14:50 +0200, Matthias Schiffer wrote:
> On Fri, 2020-08-21 at 15:41 +0200, Stefan Agner wrote:
> > Hi Matthias,
> >
> > On 2020-08-20 12:58, Matthias Schiffer wrote:
> > > The PIXCLK needs to be enabled in SCFG before accessing the DCU on LS1021A,
> > > or the access will hang.
> >
> > Hm, this seems a rather ad-hoc access to SCFG from the DCU. We do
> > support a pixel clock in the device tree bindings of fsl-dcu, so ideally
> > we should enable the pixel clock through the clock framework.
> >
> > On the other hand, I guess that would mean adding a clock driver to flip
> > a single bit, which seems a bit excessive too.
> >
> > I'd like a second opinion on that. Adding clk framework maintainers.
>
> It's been a while, and nobody else has given their opinion. How should
> we proceed with this patch?
>
> Matthias
This patch is still blocked on a maintainer decision. Should I send a
rebased version of the current solution, or do we want to have a proper
clk driver to flip this bit?
>
>
> >
> > --
> > Stefan
> >
> > >
> > > Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> > > ---
> > > drivers/gpu/drm/fsl-dcu/Kconfig | 1 +
> > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 25 +++++++++++++++++++++++
> > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 3 +++
> > > 3 files changed, 29 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/fsl-dcu/Kconfig b/drivers/gpu/drm/fsl-dcu/Kconfig
> > > index d7dd8ba90e3a..9e5a35e7c00c 100644
> > > --- a/drivers/gpu/drm/fsl-dcu/Kconfig
> > > +++ b/drivers/gpu/drm/fsl-dcu/Kconfig
> > > @@ -8,6 +8,7 @@ config DRM_FSL_DCU
> > > select DRM_PANEL
> > > select REGMAP_MMIO
> > > select VIDEOMODE_HELPERS
> > > + select MFD_SYSCON if SOC_LS1021A
> > > help
> > > Choose this option if you have an Freescale DCU chipset.
> > > If M is selected the module will be called fsl-dcu-drm.
> > > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > > index abbc1ddbf27f..8a7556655581 100644
> > > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> > > @@ -51,6 +51,23 @@ static const struct regmap_config fsl_dcu_regmap_config = {
> > > .volatile_reg = fsl_dcu_drm_is_volatile_reg,
> > > };
> > >
> > > +static int fsl_dcu_scfg_config_ls1021a(struct device_node *np)
> > > +{
> > > + struct regmap *scfg;
> > > +
> > > + scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
> > > + if (IS_ERR(scfg))
> > > + return PTR_ERR(scfg);
> > > +
> > > + /*
> > > + * For simplicity, enable the PIXCLK unconditionally. It might
> > > + * be possible to disable the clock in PM or on unload as a future
> > > + * improvement.
> > > + */
> > > + return regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,
> > > + SCFG_PIXCLKCR_PXCEN);
> > > +}
> > > +
> > > static void fsl_dcu_irq_uninstall(struct drm_device *dev)
> > > {
> > > struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> > > @@ -70,6 +87,14 @@ static int fsl_dcu_load(struct drm_device *dev,
> > > unsigned long flags)
> > > return ret;
> > > }
> > >
> > > + if (of_device_is_compatible(fsl_dev->np, "fsl,ls1021a-dcu")) {
> > > + ret = fsl_dcu_scfg_config_ls1021a(fsl_dev->np);
> > > + if (ret < 0) {
> > > + dev_err(dev->dev, "failed to enable pixclk\n");
> > > + goto done;
> > > + }
> > > + }
> > > +
> > > ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
> > > if (ret < 0) {
> > > dev_err(dev->dev, "failed to initialize vblank\n");
> > > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > > index e2049a0e8a92..566396013c04 100644
> > > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> > > @@ -160,6 +160,9 @@
> > > #define FSL_DCU_ARGB4444 12
> > > #define FSL_DCU_YUV422 14
> > >
> > > +#define SCFG_PIXCLKCR 0x28
> > > +#define SCFG_PIXCLKCR_PXCEN BIT(31)
> > > +
> > > #define VF610_LAYER_REG_NUM 9
> > > #define LS1021A_LAYER_REG_NUM 10
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH] drm: fsl-dcu: enable PIXCLK on LS1021A
2021-10-05 12:35 ` Matthias Schiffer
@ 2021-10-05 13:45 ` Stefan Agner
0 siblings, 0 replies; 10+ messages in thread
From: Stefan Agner @ 2021-10-05 13:45 UTC (permalink / raw)
To: Matthias Schiffer
Cc: sboyd, mturquette, Alison Wang, David Airlie, Daniel Vetter,
dri-devel, linux-kernel
On 2021-10-05 14:35, Matthias Schiffer wrote:
> On Thu, 2021-09-16 at 14:50 +0200, Matthias Schiffer wrote:
>> On Fri, 2020-08-21 at 15:41 +0200, Stefan Agner wrote:
>> > Hi Matthias,
>> >
>> > On 2020-08-20 12:58, Matthias Schiffer wrote:
>> > > The PIXCLK needs to be enabled in SCFG before accessing the DCU on LS1021A,
>> > > or the access will hang.
>> >
>> > Hm, this seems a rather ad-hoc access to SCFG from the DCU. We do
>> > support a pixel clock in the device tree bindings of fsl-dcu, so ideally
>> > we should enable the pixel clock through the clock framework.
>> >
>> > On the other hand, I guess that would mean adding a clock driver to flip
>> > a single bit, which seems a bit excessive too.
>> >
>> > I'd like a second opinion on that. Adding clk framework maintainers.
>>
>> It's been a while, and nobody else has given their opinion. How should
>> we proceed with this patch?
>>
>> Matthias
>
> This patch is still blocked on a maintainer decision. Should I send a
> rebased version of the current solution, or do we want to have a proper
> clk driver to flip this bit?
>
The clock maintainers haven't stated an opinion. I've seen similar hacks
for reset and other bits in other places, so I guess it's fine.
Can you also drop the np argument from fsl_dcu_scfg_config_ls1021a(), it
seems unnecessary.
--
Stefan
>
>>
>>
>> >
>> > --
>> > Stefan
>> >
>> > >
>> > > Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
>> > > ---
>> > > drivers/gpu/drm/fsl-dcu/Kconfig | 1 +
>> > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 25 +++++++++++++++++++++++
>> > > drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 3 +++
>> > > 3 files changed, 29 insertions(+)
>> > >
>> > > diff --git a/drivers/gpu/drm/fsl-dcu/Kconfig b/drivers/gpu/drm/fsl-dcu/Kconfig
>> > > index d7dd8ba90e3a..9e5a35e7c00c 100644
>> > > --- a/drivers/gpu/drm/fsl-dcu/Kconfig
>> > > +++ b/drivers/gpu/drm/fsl-dcu/Kconfig
>> > > @@ -8,6 +8,7 @@ config DRM_FSL_DCU
>> > > select DRM_PANEL
>> > > select REGMAP_MMIO
>> > > select VIDEOMODE_HELPERS
>> > > + select MFD_SYSCON if SOC_LS1021A
>> > > help
>> > > Choose this option if you have an Freescale DCU chipset.
>> > > If M is selected the module will be called fsl-dcu-drm.
>> > > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> > > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> > > index abbc1ddbf27f..8a7556655581 100644
>> > > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> > > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
>> > > @@ -51,6 +51,23 @@ static const struct regmap_config fsl_dcu_regmap_config = {
>> > > .volatile_reg = fsl_dcu_drm_is_volatile_reg,
>> > > };
>> > >
>> > > +static int fsl_dcu_scfg_config_ls1021a(struct device_node *np)
>> > > +{
>> > > + struct regmap *scfg;
>> > > +
>> > > + scfg = syscon_regmap_lookup_by_compatible("fsl,ls1021a-scfg");
>> > > + if (IS_ERR(scfg))
>> > > + return PTR_ERR(scfg);
>> > > +
>> > > + /*
>> > > + * For simplicity, enable the PIXCLK unconditionally. It might
>> > > + * be possible to disable the clock in PM or on unload as a future
>> > > + * improvement.
>> > > + */
>> > > + return regmap_update_bits(scfg, SCFG_PIXCLKCR, SCFG_PIXCLKCR_PXCEN,
>> > > + SCFG_PIXCLKCR_PXCEN);
>> > > +}
>> > > +
>> > > static void fsl_dcu_irq_uninstall(struct drm_device *dev)
>> > > {
>> > > struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
>> > > @@ -70,6 +87,14 @@ static int fsl_dcu_load(struct drm_device *dev,
>> > > unsigned long flags)
>> > > return ret;
>> > > }
>> > >
>> > > + if (of_device_is_compatible(fsl_dev->np, "fsl,ls1021a-dcu")) {
>> > > + ret = fsl_dcu_scfg_config_ls1021a(fsl_dev->np);
>> > > + if (ret < 0) {
>> > > + dev_err(dev->dev, "failed to enable pixclk\n");
>> > > + goto done;
>> > > + }
>> > > + }
>> > > +
>> > > ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
>> > > if (ret < 0) {
>> > > dev_err(dev->dev, "failed to initialize vblank\n");
>> > > diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
>> > > b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
>> > > index e2049a0e8a92..566396013c04 100644
>> > > --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
>> > > +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
>> > > @@ -160,6 +160,9 @@
>> > > #define FSL_DCU_ARGB4444 12
>> > > #define FSL_DCU_YUV422 14
>> > >
>> > > +#define SCFG_PIXCLKCR 0x28
>> > > +#define SCFG_PIXCLKCR_PXCEN BIT(31)
>> > > +
>> > > #define VF610_LAYER_REG_NUM 9
>> > > #define LS1021A_LAYER_REG_NUM 10
^ permalink raw reply [flat|nested] 10+ messages in thread