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

From: Neil Armstrong
Date: Tue Apr 28 2020 - 05:21:59 EST


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@xxxxxxxxxxxx>
---
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