fbdev: sh_mobile_hdmi: support hot-plugging of different HDMI / DVI displays

With this patch hot-plugging of an HDMI or a DVI monitor can select a different
video mode and reconfigure the LCDC and HDMI controllers accordingly. Due to a
lack of a standard API to inform framebuffer users of a changed video mode, the
framebuffer configuration is preserved regardless of a specific mode, selected
for the monitor. As described in a previous patch, this leads to smaller
framebuffers being displayed on larger monitors or a part of a larger
framebuffer being displayed on a smaller resolution monitor.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 170 insertions, 64 deletions

diff --git a/drivers/video/sh_mobile_hdmi.c b/drivers/video/sh_mobile_hdmi.c
index 2260fd7edd95..4d6ab86e9518 100644
--- a/drivers/video/sh_mobile_hdmi.c
+++ b/drivers/video/sh_mobile_hdmi.c
@@ -214,6 +214,7 @@ struct sh_hdmi {
         struct mutex mutex;             /* Protect the info pointer */
         struct delayed_work edid_work;
         struct fb_var_screeninfo var;
+        struct fb_monspecs monspec;
 };
 
 static void hdmi_write(struct sh_hdmi *hdmi, u8 data, u8 reg)
@@ -610,11 +611,12 @@ static void sh_hdmi_configure(struct sh_hdmi *hdmi)
         hdmi_write(hdmi, 0x40, HDMI_SYSTEM_CTRL);
 }
 
-static void sh_hdmi_read_edid(struct sh_hdmi *hdmi)
+static int sh_hdmi_read_edid(struct sh_hdmi *hdmi)
 {
         struct fb_var_screeninfo tmpvar;
         /* TODO: When we are ready to use EDID, use this to fill &hdmi->var */
         struct fb_var_screeninfo *var = &tmpvar;
+        const struct fb_videomode *mode, *found = NULL;
         int i;
         u8 edid[128];
 
@@ -634,20 +636,84 @@ static void sh_hdmi_read_edid(struct sh_hdmi *hdmi)
 #ifdef DEBUG
         printk(KERN_CONT "\n");
 #endif
-        fb_parse_edid(edid, var);
-        dev_dbg(hdmi->dev, "%u-%u-%u-%u x %u-%u-%u-%u @ %lu kHz monitor detected\n",
-                var->left_margin, var->xres, var->right_margin, var->hsync_len,
-                var->upper_margin, var->yres, var->lower_margin, var->vsync_len,
-                PICOS2KHZ(var->pixclock));
-
-        if ((hdmi->var.xres == 720 && hdmi->var.yres == 480) ||
-            (hdmi->var.xres == 1280 && hdmi->var.yres == 720) ||
-            (hdmi->var.xres == 1920 && hdmi->var.yres == 1080))
+
+        fb_edid_to_monspecs(edid, &hdmi->monspec);
+
+        /* First look for an exact match */
+        for (i = 0, mode = hdmi->monspec.modedb; i < hdmi->monspec.modedb_len;
+             i++, mode++) {
+                dev_dbg(hdmi->dev, "%u-%u-%u-%u x %u-%u-%u-%u @ %lu kHz monitor detected\n",
+                        mode->left_margin, mode->xres,
+                        mode->right_margin, mode->hsync_len,
+                        mode->upper_margin, mode->yres,
+                        mode->lower_margin, mode->vsync_len,
+                        PICOS2KHZ(mode->pixclock));
+                if (!found && hdmi->info) {
+                        fb_videomode_to_var(var, mode);
+                        found = fb_match_mode(var, &hdmi->info->modelist);
+                        /*
+                         * If an exact match found, we're good to bail out, but
+                         * continue to print out all modes
+                         */
+                }
+        }
+
+        /*
+         * The monitor might also work with a mode, that is smaller, than one of
+         * its modes, use the first (default) one for this
+         */
+        if (!found && hdmi->info && hdmi->monspec.modedb_len) {
+                struct fb_modelist *modelist;
+                unsigned int min_err = UINT_MAX, err;
+                const struct fb_videomode *mon_mode = hdmi->monspec.modedb;
+
+                list_for_each_entry(modelist, &hdmi->info->modelist, list) {
+                        mode = &modelist->mode;
+                        dev_dbg(hdmi->dev, "matching %ux%u to %ux%u\n", mode->xres, mode->yres,
+                                 mon_mode->xres, mon_mode->yres);
+                        if (mode->xres <= mon_mode->xres && mode->yres <= mon_mode->yres) {
+                                err = mon_mode->xres - mode->xres + mon_mode->yres - mode->yres;
+                                if (!err) {
+                                        found = mode;
+                                        break;
+                                }
+                                if (err < min_err) {
+                                        found = mode;
+                                        min_err = err;
+                                }
+                        }
+                }
+        }
+
+        /* Nothing suitable specified by the platform: use monitor's first mode */
+        if (!found && hdmi->monspec.modedb_len)
+                found = hdmi->monspec.modedb;
+
+        /* No valid timing info in EDID - last resort: use platform default mode */
+        if (!found && hdmi->info) {
+                struct fb_modelist *modelist = list_entry(hdmi->info->modelist.next,
+                                                          struct fb_modelist, list);
+                found = &modelist->mode;
+        }
+
+        /* No cookie today */
+        if (!found)
+                return -ENXIO;
+
+        dev_dbg(hdmi->dev, "best \"%s\" %ux%u@%ups\n", found->name,
+                found->xres, found->yres, found->pixclock);
+
+        if ((found->xres == 720 && found->yres == 480) ||
+            (found->xres == 1280 && found->yres == 720) ||
+            (found->xres == 1920 && found->yres == 1080))
                 hdmi->preprogrammed_mode = true;
         else
                 hdmi->preprogrammed_mode = false;
 
+        fb_videomode_to_var(&hdmi->var, found);
         sh_hdmi_external_video_param(hdmi);
+
+        return 0;
 }
 
 static irqreturn_t sh_hdmi_hotplug(int irq, void *dev_id)
@@ -770,12 +836,73 @@ static void sh_hdmi_display_off(void *arg)
         hdmi_write(hdmi, 0x10, HDMI_SYSTEM_CTRL);
 }
 
+static bool sh_hdmi_must_reconfigure(struct sh_hdmi *hdmi)
+{
+        struct fb_info *info = hdmi->info;
+        struct sh_mobile_lcdc_chan *ch = info->par;
+        struct fb_var_screeninfo *new_var = &hdmi->var, *old_var = &ch->display_var;
+        struct fb_videomode mode1, mode2;
+
+        fb_var_to_videomode(&mode1, old_var);
+        fb_var_to_videomode(&mode2, new_var);
+
+        dev_dbg(info->dev, "Old %ux%u, new %ux%u\n",
+                mode1.xres, mode1.yres, mode2.xres, mode2.yres);
+
+        if (fb_mode_is_equal(&mode1, &mode2))
+                return false;
+
+        dev_dbg(info->dev, "Switching %u -> %u lines\n",
+                mode1.yres, mode2.yres);
+        *old_var = *new_var;
+
+        return true;
+}
+
+/**
+ * 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
+ */
+static long sh_hdmi_clk_configure(struct sh_hdmi *hdmi, unsigned long pixclock)
+{
+        long rate;
+        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 (ret < 0) {
+                        dev_warn(hdmi->dev, "Cannot set rate %ld: %d\n", rate, ret);
+                        rate = 0;
+                } else {
+                        dev_dbg(hdmi->dev, "HDMI set frequency %lu\n", rate);
+                }
+        } else {
+                rate = 0;
+                dev_warn(hdmi->dev, "Cannot get suitable rate: %ld\n", rate);
+        }
+
+        ret = clk_enable(hdmi->hdmi_clk);
+        if (ret < 0) {
+                dev_err(hdmi->dev, "Cannot enable clock: %d\n", ret);
+                return ret;
+        }
+
+        return rate;
+}
+
 /* Hotplug interrupt occurred, read EDID */
 static void sh_hdmi_edid_work_fn(struct work_struct *work)
 {
         struct sh_hdmi *hdmi = container_of(work, struct sh_hdmi, edid_work.work);
         struct sh_mobile_hdmi_info *pdata = hdmi->dev->platform_data;
         struct sh_mobile_lcdc_chan *ch;
+        int ret;
 
         dev_dbg(hdmi->dev, "%s(%p): begin, hotplug status %d\n", __func__,
                 pdata->lcd_dev, hdmi->hp_state);
@@ -786,9 +913,19 @@ static void sh_hdmi_edid_work_fn(struct work_struct *work)
         mutex_lock(&hdmi->mutex);
 
         if (hdmi->hp_state == HDMI_HOTPLUG_EDID_DONE) {
-                pm_runtime_get_sync(hdmi->dev);
                 /* A device has been plugged in */
-                sh_hdmi_read_edid(hdmi);
+                pm_runtime_get_sync(hdmi->dev);
+
+                ret = sh_hdmi_read_edid(hdmi);
+                if (ret < 0)
+                        goto out;
+
+                /* Reconfigure the clock */
+                clk_disable(hdmi->hdmi_clk);
+                ret = sh_hdmi_clk_configure(hdmi, hdmi->var.pixclock);
+                if (ret < 0)
+                        goto out;
+
                 msleep(10);
                 sh_hdmi_configure(hdmi);
                 /* Switched to another (d) power-save mode */
@@ -802,18 +939,24 @@ static void sh_hdmi_edid_work_fn(struct work_struct *work)
                 acquire_console_sem();
 
                 /* HDMI plug in */
-                ch->display_var = hdmi->var;
-                if (hdmi->info->state != FBINFO_STATE_RUNNING) {
-                        fb_set_suspend(hdmi->info, 0);
-                } else {
+                if (!sh_hdmi_must_reconfigure(hdmi) &&
+                    hdmi->info->state == FBINFO_STATE_RUNNING) {
+                        /*
+                         * First activation with the default monitor - just turn
+                         * on, if we run a resume here, the logo disappears
+                         */
                         if (lock_fb_info(hdmi->info)) {
                                 sh_hdmi_display_on(hdmi, hdmi->info);
                                 unlock_fb_info(hdmi->info);
                         }
+                } else {
+                        /* New monitor or have to wake up */
+                        fb_set_suspend(hdmi->info, 0);
                 }
 
                 release_console_sem();
         } else {
+                ret = 0;
                 if (!hdmi->info)
                         goto out;
 
@@ -824,9 +967,12 @@ static void sh_hdmi_edid_work_fn(struct work_struct *work)
 
                 release_console_sem();
                 pm_runtime_put(hdmi->dev);
+                fb_destroy_modedb(hdmi->monspec.modedb);
         }
 
 out:
+        if (ret < 0)
+                hdmi->hp_state = HDMI_HOTPLUG_DISCONNECTED;
         mutex_unlock(&hdmi->mutex);
 
         dev_dbg(hdmi->dev, "%s(%p): end\n", __func__, pdata->lcd_dev);
@@ -905,31 +1051,13 @@ static int __init sh_hdmi_probe(struct platform_device *pdev)
                 goto egetclk;
         }
 
-        /* TODO: reconfigure the clock on monitor plug in */
-        rate = PICOS2KHZ(pdata->lcd_chan->lcd_cfg[0].pixclock) * 1000;
-
-        rate = clk_round_rate(hdmi->hdmi_clk, rate);
+        rate = sh_hdmi_clk_configure(hdmi, pdata->lcd_chan->lcd_cfg[0].pixclock);
         if (rate < 0) {
                 ret = rate;
-                dev_err(&pdev->dev, "Cannot get suitable rate: %ld\n", rate);
-                goto erate;
-        }
-
-        ret = clk_set_rate(hdmi->hdmi_clk, rate);
-        if (ret < 0) {
-                dev_err(&pdev->dev, "Cannot set rate %ld: %d\n", rate, ret);
                 goto erate;
         }
 
-        dev_dbg(hdmi->dev, "HDMI set frequency %lu\n", rate);
-
-        ret = clk_enable(hdmi->hdmi_clk);
-        if (ret < 0) {
-                dev_err(&pdev->dev, "Cannot enable clock: %d\n", ret);
-                goto eclkenable;
-        }
-
-        dev_info(&pdev->dev, "Enabled HDMI clock at %luHz\n", rate);
+        dev_dbg(&pdev->dev, "Enabled HDMI clock at %luHz\n", rate);
 
         if (!request_mem_region(res->start, resource_size(res), dev_name(&pdev->dev))) {
                 dev_err(&pdev->dev, "HDMI register region already claimed\n");
@@ -946,11 +1074,9 @@ static int __init sh_hdmi_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, hdmi);
 
-#if 1
         /* 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));
-#endif
 
         /* Set up LCDC callbacks */
         board_cfg = &pdata->lcd_chan->board_cfg;
@@ -980,7 +1106,6 @@ emap:
         release_mem_region(res->start, resource_size(res));
 ereqreg:
         clk_disable(hdmi->hdmi_clk);
-eclkenable:
 erate:
         clk_put(hdmi->hdmi_clk);
 egetclk:
diff --git a/drivers/video/sh_mobile_lcdcfb.c b/drivers/video/sh_mobile_lcdcfb.c
index 946a810801af..b4a878624510 100644
--- a/drivers/video/sh_mobile_lcdcfb.c
+++ b/drivers/video/sh_mobile_lcdcfb.c
@@ -944,6 +944,7 @@ static int sh_mobile_lcdc_notify(struct notifier_block *nb,
         struct sh_mobile_lcdc_chan *ch = info->par;
         struct sh_mobile_lcdc_board_cfg *board_cfg = &ch->cfg.board_cfg;
         struct fb_var_screeninfo *var;
+        int ret;
 
         if (&ch->lcdc->notifier != nb)
                 return NOTIFY_DONE;
@@ -958,6 +959,7 @@ static int sh_mobile_lcdc_notify(struct notifier_block *nb,
                         module_put(board_cfg->owner);
                 }
                 pm_runtime_put(info->device);
+                sh_mobile_lcdc_stop(ch->lcdc);
                 break;
         case FB_EVENT_RESUME:
                 var = &info->var;
@@ -968,31 +970,9 @@ static int sh_mobile_lcdc_notify(struct notifier_block *nb,
                         module_put(board_cfg->owner);
                 }
 
-                /* Check if the new display is not in our modelist */
-                if (ch->info->modelist.next &&
-                    !fb_match_mode(var, &ch->info->modelist)) {
-                        struct fb_videomode mode;
-                        int ret;
-
-                        /* Can we handle this display? */
-                        if (var->xres > ch->cfg.lcd_cfg[0].xres ||
-                            var->yres > ch->cfg.lcd_cfg[0].yres)
-                                /*
-                                 * LCDC resume failed, no need to continue with
-                                 * the notifier chain
-                                 */
-                                return notifier_from_errno(-ENOMEM);
-
-                        /* Add to the modelist */
-                        fb_var_to_videomode(&mode, var);
-                        ret = fb_add_videomode(&mode, &ch->info->modelist);
-                        if (ret < 0)
-                                return notifier_from_errno(ret);
-                }
-
-                pm_runtime_get_sync(info->device);
-
-                sh_mobile_lcdc_geometry(ch);
+                ret = sh_mobile_lcdc_start(ch->lcdc);
+                if (!ret)
+                        pm_runtime_get_sync(info->device);
         }
 
         return NOTIFY_OK;
@@ -1181,6 +1161,7 @@ static int __devinit sh_mobile_lcdc_probe(struct platform_device *pdev)
                         }
                 }
 
+                fb_videomode_to_modelist(ch->cfg.lcd_cfg, ch->cfg.num_cfg, &info->modelist);
                 error = register_framebuffer(info);
                 if (error < 0)
                         goto err1;