From c36940e678fc30779c99246c034deca1fed61ae4 Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Tue, 2 Nov 2010 11:27:16 +0000 Subject: [PATCH] fbdev: sh_mobile_hdmi: add support for more precise HDMI clock configuration 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 Signed-off-by: Paul Mundt --- 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 d7df103..ef41c21 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; @@ -1166,13 +1181,22 @@ 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))) { @@ -1190,10 +1214,6 @@ 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; @@ -1206,6 +1226,10 @@ 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 -- 2.7.4