From: Tomasz Stanislawski <t.stanislaws@samsung.com>
Date: Thu, 19 Dec 2013 15:24:07 +0000 (+0100)
Subject: drm: exynos: hdmi: add support for pixel clock limitation
X-Git-Tag: submit/tizen/20141121.110247~2653
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c64acb223b047da447c2a23b1e8a6e36132cfdbd;p=platform%2Fkernel%2Flinux-3.10.git

drm: exynos: hdmi: add support for pixel clock limitation

Adds support for limitation of maximal pixel clock of HDMI
signal. This feature is needed on boards that contains
lines or bridges with frequency limitations.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Change-Id: I4cc38e995feeaca77b73e9ea0197d67f99d57715
---

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index 87c3f42..a48cf75 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -201,6 +201,7 @@ struct hdmi_context {
 	struct hdmi_resources		res;
 
 	int				hpd_gpio;
+	u32				max_pixel_clock;
 
 	enum hdmi_type			type;
 };
@@ -801,6 +802,8 @@ static int hdmi_check_mode(void *ctx, struct drm_display_mode *mode)
 		(mode->flags & DRM_MODE_FLAG_INTERLACE) ? true :
 		false, mode->clock * 1000);
 
+	if (mode->clock * 1000 > hdata->max_pixel_clock)
+		return -E2BIG;
 	ret = hdmi_find_phy_conf(hdata, mode->clock * 1000);
 	if (ret < 0)
 		return ret;
@@ -1868,6 +1871,8 @@ static struct s5p_hdmi_platform_data *drm_hdmi_dt_parse_pdata
 		return NULL;
 	}
 
+	of_property_read_u32(np, "max-pixel-clock", &pd->max_pixel_clock);
+
 	return pd;
 }
 #else
@@ -1934,6 +1939,11 @@ static int hdmi_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	if (!pdata->max_pixel_clock) {
+		DRM_LOG("max-pixel-clock is zero, using INF\n");
+		pdata->max_pixel_clock = ULONG_MAX;
+	}
+
 	drm_hdmi_ctx = devm_kzalloc(dev, sizeof(*drm_hdmi_ctx),
 								GFP_KERNEL);
 	if (!drm_hdmi_ctx)
@@ -1964,6 +1974,7 @@ static int hdmi_probe(struct platform_device *pdev)
 	}
 
 	hdata->hpd_gpio = pdata->hpd_gpio;
+	hdata->max_pixel_clock = pdata->max_pixel_clock;
 	hdata->dev = dev;
 
 	ret = hdmi_resources_init(hdata);
diff --git a/include/media/s5p_hdmi.h b/include/media/s5p_hdmi.h
index 181642b..7272d65 100644
--- a/include/media/s5p_hdmi.h
+++ b/include/media/s5p_hdmi.h
@@ -31,6 +31,7 @@ struct s5p_hdmi_platform_data {
 	int mhl_bus;
 	struct i2c_board_info *mhl_info;
 	int hpd_gpio;
+	u32 max_pixel_clock;
 };
 
 #endif /* S5P_HDMI_H */