[PATCH v2] drm/meson: add mode selection limits against specific SoC revisions

[PATCH v2] drm/meson: add mode selection limits against specific SoC revisions

[Neil Armstrong]

The Amlogic S805X/Y uses the same die as the S905X, but with more
limited graphics capabilities.

This adds a soc version detection adding specific limitations on the HDMI
mode selections.

Here, we limit to HDMI 1.3a max HDMI PHY clock frequency.

Changes sinces v1:
- Moved frequency check in the vclk code, and also checks DMT modes

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/meson/meson_drv.c     | 29 ++++++++++++++++++++++++++-
 drivers/gpu/drm/meson/meson_drv.h     |  6 ++++++
 drivers/gpu/drm/meson/meson_dw_hdmi.c |  2 +-
 drivers/gpu/drm/meson/meson_vclk.c    | 16 ++++++++++++++-
 drivers/gpu/drm/meson/meson_vclk.h    |  3 ++-
 5 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index 6f29fab79952..621f6de0f076 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -11,6 +11,7 @@
 #include <linux/component.h>
 #include <linux/module.h>
 #include <linux/of_graph.h>
+#include <linux/sys_soc.h>
 #include <linux/platform_device.h>
 #include <linux/soc/amlogic/meson-canvas.h>
 
@@ -183,6 +184,24 @@ static void meson_remove_framebuffers(void)
 	kfree(ap);
 }
 
+struct meson_drm_soc_attr {
+	struct meson_drm_soc_limits limits;
+	const struct soc_device_attribute *attrs;
+};
+
+static const struct meson_drm_soc_attr meson_drm_soc_attrs[] = {
+	/* S805X/S805Y HDMI PLL won't lock for HDMI PHY freq > 1,65GHz */
+	{
+		.limits = {
+			.max_hdmi_phy_freq = 1650000,
+		},
+		.attrs = (const struct soc_device_attribute []) {
+			{ .soc_id = "GXL (S805*)", },
+			{ /* sentinel */ },
+		}
+	},
+};
+
 static int meson_drv_bind_master(struct device *dev, bool has_components)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -191,7 +210,7 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 	struct drm_device *drm;
 	struct resource *res;
 	void __iomem *regs;
-	int ret;
+	int ret, i;
 
 	/* Checks if an output connector is available */
 	if (!meson_vpu_has_available_connectors(dev)) {
@@ -281,6 +300,14 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 	if (ret)
 		goto free_drm;
 
+	/* Assign limits per soc revision/package */
+	for (i = 0 ; i < ARRAY_SIZE(meson_drm_soc_attrs) ; ++i) {
+		if (soc_device_match(meson_drm_soc_attrs[i].attrs)) {
+			priv->limits = &meson_drm_soc_attrs[i].limits;
+			break;
+		}
+	}
+
 	/* Remove early framebuffers (ie. simplefb) */
 	meson_remove_framebuffers();
 
diff --git a/drivers/gpu/drm/meson/meson_drv.h b/drivers/gpu/drm/meson/meson_drv.h
index 04fdf3826643..5b23704a80d6 100644
--- a/drivers/gpu/drm/meson/meson_drv.h
+++ b/drivers/gpu/drm/meson/meson_drv.h
@@ -30,6 +30,10 @@ struct meson_drm_match_data {
 	struct meson_afbcd_ops *afbcd_ops;
 };
 
+struct meson_drm_soc_limits {
+	unsigned int max_hdmi_phy_freq;
+};
+
 struct meson_drm {
 	struct device *dev;
 	enum vpu_compatible compat;
@@ -48,6 +52,8 @@ struct meson_drm {
 	struct drm_plane *primary_plane;
 	struct drm_plane *overlay_plane;
 
+	const struct meson_drm_soc_limits *limits;
+
 	/* Components Data */
 	struct {
 		bool osd1_enabled;
diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index e8c94915a4fc..5be963e9db05 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -695,7 +695,7 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 	dev_dbg(connector->dev->dev, "%s: vclk:%d phy=%d venc=%d hdmi=%d\n",
 		__func__, phy_freq, vclk_freq, venc_freq, hdmi_freq);
 
-	return meson_vclk_vic_supported_freq(phy_freq, vclk_freq);
+	return meson_vclk_vic_supported_freq(priv, phy_freq, vclk_freq);
 }
 
 /* Encoder */
diff --git a/drivers/gpu/drm/meson/meson_vclk.c b/drivers/gpu/drm/meson/meson_vclk.c
index fdf26dac9fa8..0eb86943a358 100644
--- a/drivers/gpu/drm/meson/meson_vclk.c
+++ b/drivers/gpu/drm/meson/meson_vclk.c
@@ -725,6 +725,13 @@ meson_vclk_dmt_supported_freq(struct meson_drm *priv, unsigned int freq)
 	/* In DMT mode, path after PLL is always /10 */
 	freq *= 10;
 
+	/* Check against soc revision/package limits */
+	if (priv->limits) {
+		if (priv->limits->max_hdmi_phy_freq &&
+		    freq > priv->limits->max_hdmi_phy_freq)
+			return MODE_CLOCK_HIGH;
+	}
+
 	if (meson_hdmi_pll_find_params(priv, freq, &m, &frac, &od))
 		return MODE_OK;
 
@@ -762,7 +769,7 @@ static void meson_hdmi_pll_generic_set(struct meson_drm *priv,
 }
 
 enum drm_mode_status
-meson_vclk_vic_supported_freq(unsigned int phy_freq,
+meson_vclk_vic_supported_freq(struct meson_drm *priv, unsigned int phy_freq,
 			      unsigned int vclk_freq)
 {
 	int i;
@@ -770,6 +777,13 @@ meson_vclk_vic_supported_freq(unsigned int phy_freq,
 	DRM_DEBUG_DRIVER("phy_freq = %d vclk_freq = %d\n",
 			 phy_freq, vclk_freq);
 
+	/* Check against soc revision/package limits */
+	if (priv->limits) {
+		if (priv->limits->max_hdmi_phy_freq &&
+		    phy_freq > priv->limits->max_hdmi_phy_freq)
+			return MODE_CLOCK_HIGH;
+	}
+
 	for (i = 0 ; params[i].pixel_freq ; ++i) {
 		DRM_DEBUG_DRIVER("i = %d pixel_freq = %d alt = %d\n",
 				 i, params[i].pixel_freq,
diff --git a/drivers/gpu/drm/meson/meson_vclk.h b/drivers/gpu/drm/meson/meson_vclk.h
index aed0ab2efa71..60617aaf18dd 100644
--- a/drivers/gpu/drm/meson/meson_vclk.h
+++ b/drivers/gpu/drm/meson/meson_vclk.h
@@ -25,7 +25,8 @@ enum {
 enum drm_mode_status
 meson_vclk_dmt_supported_freq(struct meson_drm *priv, unsigned int freq);
 enum drm_mode_status
-meson_vclk_vic_supported_freq(unsigned int phy_freq, unsigned int vclk_freq);
+meson_vclk_vic_supported_freq(struct meson_drm *priv, unsigned int phy_freq,
+			      unsigned int vclk_freq);
 
 void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
 		      unsigned int phy_freq, unsigned int vclk_freq,
-- 
2.22.0

Re: [PATCH v2] drm/meson: add mode selection limits against specific SoC revisions

[Martin Blumenstingl]

Hi Neil,

On Tue, Apr 28, 2020 at 11:21 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> The Amlogic S805X/Y uses the same die as the S905X, but with more
> limited graphics capabilities.
>
> This adds a soc version detection adding specific limitations on the HDMI
> mode selections.
>
> Here, we limit to HDMI 1.3a max HDMI PHY clock frequency.
for my own education: 1.65GHz from the PLL will be divided down to 165MHz
isn't this more like the limit of HDMI 1.2a?

> Changes sinces v1:
> - Moved frequency check in the vclk code, and also checks DMT modes
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

This looks good to me based on the current limitations of meson_vclk.c
If we switch to CCF based VPU clock rate changes then we should do
this in the clock driver by calling clk_hw_set_rate_range(hdmi_pll, 0,
1.65GHz)

The good thing is: we can re-use struct meson_drm_soc_limits even
after switching to CCF.
We will just need to set the max PHY freq using
clk_round_rate(hdmi_pll, ULONG_MAX)


Martin

Re: [PATCH v2] drm/meson: add mode selection limits against specific SoC revisions

[Neil Armstrong]

Hi,

On 29/04/2020 00:03, Martin Blumenstingl wrote:
> Hi Neil,
> 
> On Tue, Apr 28, 2020 at 11:21 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
>>
>> The Amlogic S805X/Y uses the same die as the S905X, but with more
>> limited graphics capabilities.
>>
>> This adds a soc version detection adding specific limitations on the HDMI
>> mode selections.
>>
>> Here, we limit to HDMI 1.3a max HDMI PHY clock frequency.
> for my own education: 1.65GHz from the PLL will be divided down to 165MHz
> isn't this more like the limit of HDMI 1.2a?

indeed from [1] :
```
HDMI 1.3 / 1.3a:
- Higher speed: HDMI 1.3 increases its single-link bandwidth to 340 MHz (10.2 Gbps) to support the
demands of future HD display devices, such as higher resolutions, Deep Color and high frame rates.
In addition, built into the HDMI 1.3 specification is the technical foundations that will let future
versions of HDMI reach significantly higher speeds.
```

So yes, it must be HDMI 1.2a, I'll fixup while applying.

> 
>> Changes sinces v1:
>> - Moved frequency check in the vclk code, and also checks DMT modes
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> 
> This looks good to me based on the current limitations of meson_vclk.c
> If we switch to CCF based VPU clock rate changes then we should do
> this in the clock driver by calling clk_hw_set_rate_range(hdmi_pll, 0,
> 1.65GHz)
> 
> The good thing is: we can re-use struct meson_drm_soc_limits even
> after switching to CCF.
> We will just need to set the max PHY freq using
> clk_round_rate(hdmi_pll, ULONG_MAX)

Exact !

Neil

> 
> 
> Martin
> 

[1] https://denon.custhelp.com/app/answers/detail/a_id/192/~/differences-between-hdmi-versions-1.1%2C-1.2%2C-1.3a%2C-1.4-and-2.0%3F

Re: [PATCH v2] drm/meson: add mode selection limits against specific SoC revisions

[Neil Armstrong]

On 28/04/2020 11:21, Neil Armstrong wrote:
> The Amlogic S805X/Y uses the same die as the S905X, but with more
> limited graphics capabilities.
> 
> This adds a soc version detection adding specific limitations on the HDMI
> mode selections.
> 
> Here, we limit to HDMI 1.3a max HDMI PHY clock frequency.
> 
> Changes sinces v1:
> - Moved frequency check in the vclk code, and also checks DMT modes
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/gpu/drm/meson/meson_drv.c     | 29 ++++++++++++++++++++++++++-
>  drivers/gpu/drm/meson/meson_drv.h     |  6 ++++++
>  drivers/gpu/drm/meson/meson_dw_hdmi.c |  2 +-
>  drivers/gpu/drm/meson/meson_vclk.c    | 16 ++++++++++++++-
>  drivers/gpu/drm/meson/meson_vclk.h    |  3 ++-
>  5 files changed, 52 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> index 6f29fab79952..621f6de0f076 100644
> --- a/drivers/gpu/drm/meson/meson_drv.c
> +++ b/drivers/gpu/drm/meson/meson_drv.c
> @@ -11,6 +11,7 @@
>  #include <linux/component.h>
>  #include <linux/module.h>
>  #include <linux/of_graph.h>
> +#include <linux/sys_soc.h>
>  #include <linux/platform_device.h>
>  #include <linux/soc/amlogic/meson-canvas.h>
>  
> @@ -183,6 +184,24 @@ static void meson_remove_framebuffers(void)
>  	kfree(ap);
>  }
>  
> +struct meson_drm_soc_attr {
> +	struct meson_drm_soc_limits limits;
> +	const struct soc_device_attribute *attrs;
> +};
> +
> +static const struct meson_drm_soc_attr meson_drm_soc_attrs[] = {
> +	/* S805X/S805Y HDMI PLL won't lock for HDMI PHY freq > 1,65GHz */
> +	{
> +		.limits = {
> +			.max_hdmi_phy_freq = 1650000,
> +		},
> +		.attrs = (const struct soc_device_attribute []) {
> +			{ .soc_id = "GXL (S805*)", },
> +			{ /* sentinel */ },
> +		}
> +	},
> +};
> +
>  static int meson_drv_bind_master(struct device *dev, bool has_components)
>  {
>  	struct platform_device *pdev = to_platform_device(dev);
> @@ -191,7 +210,7 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>  	struct drm_device *drm;
>  	struct resource *res;
>  	void __iomem *regs;
> -	int ret;
> +	int ret, i;
>  
>  	/* Checks if an output connector is available */
>  	if (!meson_vpu_has_available_connectors(dev)) {
> @@ -281,6 +300,14 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
>  	if (ret)
>  		goto free_drm;
>  
> +	/* Assign limits per soc revision/package */
> +	for (i = 0 ; i < ARRAY_SIZE(meson_drm_soc_attrs) ; ++i) {
> +		if (soc_device_match(meson_drm_soc_attrs[i].attrs)) {
> +			priv->limits = &meson_drm_soc_attrs[i].limits;
> +			break;
> +		}
> +	}
> +
>  	/* Remove early framebuffers (ie. simplefb) */
>  	meson_remove_framebuffers();
>  
> diff --git a/drivers/gpu/drm/meson/meson_drv.h b/drivers/gpu/drm/meson/meson_drv.h
> index 04fdf3826643..5b23704a80d6 100644
> --- a/drivers/gpu/drm/meson/meson_drv.h
> +++ b/drivers/gpu/drm/meson/meson_drv.h
> @@ -30,6 +30,10 @@ struct meson_drm_match_data {
>  	struct meson_afbcd_ops *afbcd_ops;
>  };
>  
> +struct meson_drm_soc_limits {
> +	unsigned int max_hdmi_phy_freq;
> +};
> +
>  struct meson_drm {
>  	struct device *dev;
>  	enum vpu_compatible compat;
> @@ -48,6 +52,8 @@ struct meson_drm {
>  	struct drm_plane *primary_plane;
>  	struct drm_plane *overlay_plane;
>  
> +	const struct meson_drm_soc_limits *limits;
> +
>  	/* Components Data */
>  	struct {
>  		bool osd1_enabled;
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index e8c94915a4fc..5be963e9db05 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -695,7 +695,7 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
>  	dev_dbg(connector->dev->dev, "%s: vclk:%d phy=%d venc=%d hdmi=%d\n",
>  		__func__, phy_freq, vclk_freq, venc_freq, hdmi_freq);
>  
> -	return meson_vclk_vic_supported_freq(phy_freq, vclk_freq);
> +	return meson_vclk_vic_supported_freq(priv, phy_freq, vclk_freq);
>  }
>  
>  /* Encoder */
> diff --git a/drivers/gpu/drm/meson/meson_vclk.c b/drivers/gpu/drm/meson/meson_vclk.c
> index fdf26dac9fa8..0eb86943a358 100644
> --- a/drivers/gpu/drm/meson/meson_vclk.c
> +++ b/drivers/gpu/drm/meson/meson_vclk.c
> @@ -725,6 +725,13 @@ meson_vclk_dmt_supported_freq(struct meson_drm *priv, unsigned int freq)
>  	/* In DMT mode, path after PLL is always /10 */
>  	freq *= 10;
>  
> +	/* Check against soc revision/package limits */
> +	if (priv->limits) {
> +		if (priv->limits->max_hdmi_phy_freq &&
> +		    freq > priv->limits->max_hdmi_phy_freq)
> +			return MODE_CLOCK_HIGH;
> +	}
> +
>  	if (meson_hdmi_pll_find_params(priv, freq, &m, &frac, &od))
>  		return MODE_OK;
>  
> @@ -762,7 +769,7 @@ static void meson_hdmi_pll_generic_set(struct meson_drm *priv,
>  }
>  
>  enum drm_mode_status
> -meson_vclk_vic_supported_freq(unsigned int phy_freq,
> +meson_vclk_vic_supported_freq(struct meson_drm *priv, unsigned int phy_freq,
>  			      unsigned int vclk_freq)
>  {
>  	int i;
> @@ -770,6 +777,13 @@ meson_vclk_vic_supported_freq(unsigned int phy_freq,
>  	DRM_DEBUG_DRIVER("phy_freq = %d vclk_freq = %d\n",
>  			 phy_freq, vclk_freq);
>  
> +	/* Check against soc revision/package limits */
> +	if (priv->limits) {
> +		if (priv->limits->max_hdmi_phy_freq &&
> +		    phy_freq > priv->limits->max_hdmi_phy_freq)
> +			return MODE_CLOCK_HIGH;
> +	}
> +
>  	for (i = 0 ; params[i].pixel_freq ; ++i) {
>  		DRM_DEBUG_DRIVER("i = %d pixel_freq = %d alt = %d\n",
>  				 i, params[i].pixel_freq,
> diff --git a/drivers/gpu/drm/meson/meson_vclk.h b/drivers/gpu/drm/meson/meson_vclk.h
> index aed0ab2efa71..60617aaf18dd 100644
> --- a/drivers/gpu/drm/meson/meson_vclk.h
> +++ b/drivers/gpu/drm/meson/meson_vclk.h
> @@ -25,7 +25,8 @@ enum {
>  enum drm_mode_status
>  meson_vclk_dmt_supported_freq(struct meson_drm *priv, unsigned int freq);
>  enum drm_mode_status
> -meson_vclk_vic_supported_freq(unsigned int phy_freq, unsigned int vclk_freq);
> +meson_vclk_vic_supported_freq(struct meson_drm *priv, unsigned int phy_freq,
> +			      unsigned int vclk_freq);
>  
>  void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
>  		      unsigned int phy_freq, unsigned int vclk_freq,
> 

Applied to drm-misc-next with commit log fixup