The HDMI clock has to be reconfigured for different video modes. However, the
precision of the supplying SoC clock on SH-Mobile systems is often
insufficient. This patch allows to additionally reconfigure the parent clock
to achieve the optimal HDMI clock frequency, in case this is supported by the
platform.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
---
v2:
1. use clk_get_parent() instead of platform callbacks
2. don't access hardware before switching pm clock on
drivers/video/sh_mobile_hdmi.c | 112 ++++++++++++++++++++++++----------------
include/video/sh_mobile_hdmi.h | 3 +
2 files changed, 71 insertions(+), 44 deletions(-)
diff --git a/drivers/video/sh_mobile_hdmi.c b/drivers/video/sh_mobile_hdmi.c
index 55b3077..ff7f785 100644
--- a/drivers/video/sh_mobile_hdmi.c
+++ b/drivers/video/sh_mobile_hdmi.c
@@ -685,11 +685,21 @@ static void sh_hdmi_configure(struct sh_hdmi *hdmi)
}
static unsigned long sh_hdmi_rate_error(struct sh_hdmi *hdmi,
- const struct fb_videomode *mode)
+ const struct fb_videomode *mode,
+ unsigned long *hdmi_rate, unsigned long *parent_rate)
{
- long target = PICOS2KHZ(mode->pixclock) * 1000,
- rate = clk_round_rate(hdmi->hdmi_clk, target);
- unsigned long rate_error = rate > 0 ? abs(rate - target) : ULONG_MAX;
+ unsigned long target = PICOS2KHZ(mode->pixclock) * 1000, rate_error;
+ struct sh_mobile_hdmi_info *pdata = hdmi->dev->platform_data;
+
+ *hdmi_rate = clk_round_rate(hdmi->hdmi_clk, target);
+ if ((long)*hdmi_rate < 0)
+ *hdmi_rate = clk_get_rate(hdmi->hdmi_clk);
+
+ rate_error = (long)*hdmi_rate > 0 ? abs(*hdmi_rate - target) : ULONG_MAX;
+ if (rate_error && pdata->clk_optimize_parent)
+ rate_error = pdata->clk_optimize_parent(target, hdmi_rate, parent_rate);
+ else if (clk_get_parent(hdmi->hdmi_clk))
+ *parent_rate = clk_get_rate(clk_get_parent(hdmi->hdmi_clk));
dev_dbg(hdmi->dev, "%u-%u-%u-%u x %u-%u-%u-%u\n",
mode->left_margin, mode->xres,
@@ -697,14 +707,15 @@ static unsigned long sh_hdmi_rate_error(struct sh_hdmi *hdmi,
mode->upper_margin, mode->yres,
mode->lower_margin, mode->vsync_len);
- dev_dbg(hdmi->dev, "\t@%lu(+/-%lu)Hz, e=%lu / 1000, r=%uHz\n", target,
- rate_error, rate_error ? 10000 / (10 * target / rate_error) : 0,
- mode->refresh);
+ dev_dbg(hdmi->dev, "\t@%lu(+/-%lu)Hz, e=%lu / 1000, r=%uHz, p=%luHz\n", target,
+ rate_error, rate_error ? 10000 / (10 * target / rate_error) : 0,
+ mode->refresh, *parent_rate);
return rate_error;
}
-static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
+static int sh_hdmi_read_edid(struct sh_hdmi *hdmi, unsigned long *hdmi_rate,
+ unsigned long *parent_rate)
{
struct fb_var_screeninfo tmpvar;
struct fb_var_screeninfo *var = &tmpvar;
@@ -754,11 +765,14 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
for (i = 0, mode = hdmi->monspec.modedb;
f_width && f_height && i < hdmi->monspec.modedb_len && !exact_match;
i++, mode++) {
- unsigned long rate_error = sh_hdmi_rate_error(hdmi, mode);
+ unsigned long rate_error;
/* No interest in unmatching modes */
if (f_width != mode->xres || f_height != mode->yres)
continue;
+
+ rate_error = sh_hdmi_rate_error(hdmi, mode, hdmi_rate, parent_rate);
+
if (f_refresh == mode->refresh || (!f_refresh && !rate_error))
/*
* Exact match if either the refresh rate matches or it
@@ -802,7 +816,7 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
if (modelist) {
found = &modelist->mode;
- found_rate_error = sh_hdmi_rate_error(hdmi, found);
+ found_rate_error = sh_hdmi_rate_error(hdmi, found, hdmi_rate, parent_rate);
}
}
@@ -810,10 +824,6 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
if (!found)
return -ENXIO;
- dev_info(hdmi->dev, "Using %s mode %ux%u@%uHz (%luHz), clock error %luHz\n",
- modelist ? "default" : "EDID", found->xres, found->yres,
- found->refresh, PICOS2KHZ(found->pixclock) * 1000, found_rate_error);
-
if ((found->xres == 720 && found->yres == 480) ||
(found->xres == 1280 && found->yres == 720) ||
(found->xres == 1920 && found->yres == 1080))
@@ -821,6 +831,11 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
else
hdmi->preprogrammed_mode = false;
+ dev_dbg(hdmi->dev, "Using %s %s mode %ux%u@%uHz (%luHz), clock error %luHz\n",
+ modelist ? "default" : "EDID", hdmi->preprogrammed_mode ? "VIC" : "external",
+ found->xres, found->yres, found->refresh,
+ PICOS2KHZ(found->pixclock) * 1000, found_rate_error);
+
fb_videomode_to_var(&hdmi->var, found);
sh_hdmi_external_video_param(hdmi);
@@ -972,39 +987,38 @@ static bool sh_hdmi_must_reconfigure(struct sh_hdmi *hdmi)
/**
* sh_hdmi_clk_configure() - set HDMI clock frequency and enable the clock
- * @hdmi: driver context
- * @pixclock: pixel clock period in picoseconds
- * return: configured positive rate if successful
- * 0 if couldn't set the rate, but managed to enable the clock
- * negative error, if couldn't enable the clock
+ * @hdmi: driver context
+ * @hdmi_rate: HDMI clock frequency in Hz
+ * @parent_rate: if != 0 - set parent clock rate for optimal precision
+ * return: configured positive rate if successful
+ * 0 if couldn't set the rate, but managed to enable the
+ * clock, negative error, if couldn't enable the clock
*/
-static long sh_hdmi_clk_configure(struct sh_hdmi *hdmi, unsigned long pixclock)
+static long sh_hdmi_clk_configure(struct sh_hdmi *hdmi, unsigned long hdmi_rate,
+ unsigned long parent_rate)
{
- long rate;
+ struct sh_mobile_hdmi_info *pdata = hdmi->dev->platform_data;
int ret;
- rate = PICOS2KHZ(pixclock) * 1000;
- rate = clk_round_rate(hdmi->hdmi_clk, rate);
- if (rate > 0) {
- ret = clk_set_rate(hdmi->hdmi_clk, rate);
+ if (parent_rate && clk_get_parent(hdmi->hdmi_clk)) {
+ ret = clk_set_rate(clk_get_parent(hdmi->hdmi_clk), parent_rate);
if (ret < 0) {
- dev_warn(hdmi->dev, "Cannot set rate %ld: %d\n", rate, ret);
- rate = 0;
+ dev_warn(hdmi->dev, "Cannot set parent rate %ld: %d\n", parent_rate, ret);
+ hdmi_rate = clk_round_rate(hdmi->hdmi_clk, hdmi_rate);
} else {
- dev_dbg(hdmi->dev, "HDMI set frequency %lu\n", rate);
+ dev_dbg(hdmi->dev, "HDMI set parent frequency %lu\n", parent_rate);
}
- } else {
- rate = 0;
- dev_warn(hdmi->dev, "Cannot get suitable rate: %ld\n", rate);
}
- ret = clk_enable(hdmi->hdmi_clk);
+ ret = clk_set_rate(hdmi->hdmi_clk, hdmi_rate);
if (ret < 0) {
- dev_err(hdmi->dev, "Cannot enable clock: %d\n", ret);
- return ret;
+ dev_warn(hdmi->dev, "Cannot set rate %ld: %d\n", hdmi_rate, ret);
+ hdmi_rate = 0;
+ } else {
+ dev_dbg(hdmi->dev, "HDMI set frequency %lu\n", hdmi_rate);
}
- return rate;
+ return hdmi_rate;
}
/* Hotplug interrupt occurred, read EDID */
@@ -1024,16 +1038,17 @@ static void sh_hdmi_edid_work_fn(struct work_struct *work)
mutex_lock(&hdmi->mutex);
if (hdmi->hp_state == HDMI_HOTPLUG_EDID_DONE) {
+ unsigned long parent_rate = 0, hdmi_rate;
+
/* A device has been plugged in */
pm_runtime_get_sync(hdmi->dev);
- ret = sh_hdmi_read_edid(hdmi);
+ ret = sh_hdmi_read_edid(hdmi, &hdmi_rate, &parent_rate);
if (ret < 0)
goto out;
/* Reconfigure the clock */
- clk_disable(hdmi->hdmi_clk);
- ret = sh_hdmi_clk_configure(hdmi, hdmi->var.pixclock);
+ ret = sh_hdmi_clk_configure(hdmi, hdmi_rate, parent_rate);
if (ret < 0)
goto out;
@@ -1163,13 +1178,22 @@ static int __init sh_hdmi_probe(struct platform_device *pdev)
goto egetclk;
}
- /* Some arbitrary relaxed pixclock just to get things started */
- rate = sh_hdmi_clk_configure(hdmi, 37037);
+ /* An arbitrary relaxed pixclock just to get things started: from standard 480p */
+ rate = clk_round_rate(hdmi->hdmi_clk, PICOS2KHZ(37037));
+ if (rate > 0)
+ rate = sh_hdmi_clk_configure(hdmi, rate, 0);
+
if (rate < 0) {
ret = rate;
goto erate;
}
+ ret = clk_enable(hdmi->hdmi_clk);
+ if (ret < 0) {
+ dev_err(hdmi->dev, "Cannot enable clock: %d\n", ret);
+ goto erate;
+ }
+
dev_dbg(&pdev->dev, "Enabled HDMI clock at %luHz\n", rate);
if (!request_mem_region(res->start, resource_size(res), dev_name(&pdev->dev))) {
@@ -1187,10 +1211,6 @@ static int __init sh_hdmi_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, hdmi);
- /* Product and revision IDs are 0 in sh-mobile version */
- dev_info(&pdev->dev, "Detected HDMI controller 0x%x:0x%x\n",
- hdmi_read(hdmi, HDMI_PRODUCT_ID), hdmi_read(hdmi, HDMI_REVISION_ID));
-
/* Set up LCDC callbacks */
board_cfg = &pdata->lcd_chan->board_cfg;
board_cfg->owner = THIS_MODULE;
@@ -1203,6 +1223,10 @@ static int __init sh_hdmi_probe(struct platform_device *pdev)
pm_runtime_enable(&pdev->dev);
pm_runtime_resume(&pdev->dev);
+ /* Product and revision IDs are 0 in sh-mobile version */
+ dev_info(&pdev->dev, "Detected HDMI controller 0x%x:0x%x\n",
+ hdmi_read(hdmi, HDMI_PRODUCT_ID), hdmi_read(hdmi, HDMI_REVISION_ID));
+
ret = request_irq(irq, sh_hdmi_hotplug, 0,
dev_name(&pdev->dev), hdmi);
if (ret < 0) {
diff --git a/include/video/sh_mobile_hdmi.h b/include/video/sh_mobile_hdmi.h
index 1e1aa54..b569329 100644
--- a/include/video/sh_mobile_hdmi.h
+++ b/include/video/sh_mobile_hdmi.h
@@ -13,6 +13,7 @@
struct sh_mobile_lcdc_chan_cfg;
struct device;
+struct clk;
/*
* flags format
@@ -33,6 +34,8 @@ struct sh_mobile_hdmi_info {
struct sh_mobile_lcdc_chan_cfg *lcd_chan;
struct device *lcd_dev;
unsigned int flags;
+ long (*clk_optimize_parent)(unsigned long target, unsigned long *best_freq,
+ unsigned long *parent_freq);
};
#endif
--
1.7.2.3
--
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