video: sh_mobile_lcdcfb suspend/resume support

This patch adds suspend/resume support to the LCDC
driver for SuperH Mobile - sh_mobile_lcdcfb.

We simply stop hardware on suspend and start it again
on resume. For RGB panels this is trivial, but for SYS
panels in deferred io mode this becomes a bit more
difficult - we need to wait for a frame end interrupt
to make sure the clocks are balanced before stopping
the actual hardware.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 59 insertions, 7 deletions

diff --git a/drivers/video/sh_mobile_lcdcfb.c b/drivers/video/sh_mobile_lcdcfb.c
index 2c5d069e5f06..b433b8ac76d9 100644
--- a/drivers/video/sh_mobile_lcdcfb.c
+++ b/drivers/video/sh_mobile_lcdcfb.c
@@ -33,6 +33,8 @@ struct sh_mobile_lcdc_chan {
         struct fb_info info;
         dma_addr_t dma_handle;
         struct fb_deferred_io defio;
+        unsigned long frame_end;
+        wait_queue_head_t frame_end_wait;
 };
 
 struct sh_mobile_lcdc_priv {
@@ -226,7 +228,10 @@ static void sh_mobile_lcdc_deferred_io_touch(struct fb_info *info)
 static irqreturn_t sh_mobile_lcdc_irq(int irq, void *data)
 {
         struct sh_mobile_lcdc_priv *priv = data;
+        struct sh_mobile_lcdc_chan *ch;
         unsigned long tmp;
+        int is_sub;
+        int k;
 
         /* acknowledge interrupt */
         tmp = lcdc_read(priv, _LDINTR);
@@ -234,8 +239,24 @@ static irqreturn_t sh_mobile_lcdc_irq(int irq, void *data)
         tmp |= 0x000000ff ^ LDINTR_FS; /* status in low 8 */
         lcdc_write(priv, _LDINTR, tmp);
 
-        /* disable clocks */
-        sh_mobile_lcdc_clk_off(priv);
+        /* figure out if this interrupt is for main or sub lcd */
+        is_sub = (lcdc_read(priv, _LDSR) & (1 << 10)) ? 1 : 0;
+
+        /* wake up channel and disable clocks*/
+        for (k = 0; k < ARRAY_SIZE(priv->ch); k++) {
+                ch = &priv->ch[k];
+
+                if (!ch->enabled)
+                        continue;
+
+                if (is_sub == lcdc_chan_is_sublcd(ch)) {
+                        ch->frame_end = 1;
+                        wake_up(&ch->frame_end_wait);
+
+                        sh_mobile_lcdc_clk_off(priv);
+                }
+        }
+
         return IRQ_HANDLED;
 }
 
@@ -448,18 +469,27 @@ static void sh_mobile_lcdc_stop(struct sh_mobile_lcdc_priv *priv)
         struct sh_mobile_lcdc_board_cfg *board_cfg;
         int k;
 
-        /* tell the board code to disable the panel */
+        /* clean up deferred io and ask board code to disable panel */
         for (k = 0; k < ARRAY_SIZE(priv->ch); k++) {
                 ch = &priv->ch[k];
-                board_cfg = &ch->cfg.board_cfg;
-                if (board_cfg->display_off)
-                        board_cfg->display_off(board_cfg->board_data);
 
-                /* cleanup deferred io if enabled */
+                /* deferred io mode:
+                 * flush frame, and wait for frame end interrupt
+                 * clean up deferred io and enable clock
+                 */
                 if (ch->info.fbdefio) {
+                        ch->frame_end = 0;
+                        schedule_delayed_work(&ch->info.deferred_work, 0);
+                        wait_event(ch->frame_end_wait, ch->frame_end);
                         fb_deferred_io_cleanup(&ch->info);
                         ch->info.fbdefio = NULL;
+                        sh_mobile_lcdc_clk_on(priv);
                 }
+
+                board_cfg = &ch->cfg.board_cfg;
+                if (board_cfg->display_off)
+                        board_cfg->display_off(board_cfg->board_data);
+
         }
 
         /* stop the lcdc */
@@ -652,6 +682,26 @@ static int sh_mobile_lcdc_set_bpp(struct fb_var_screeninfo *var, int bpp)
         return 0;
 }
 
+static int sh_mobile_lcdc_suspend(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+
+        sh_mobile_lcdc_stop(platform_get_drvdata(pdev));
+        return 0;
+}
+
+static int sh_mobile_lcdc_resume(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+
+        return sh_mobile_lcdc_start(platform_get_drvdata(pdev));
+}
+
+static struct dev_pm_ops sh_mobile_lcdc_dev_pm_ops = {
+        .suspend = sh_mobile_lcdc_suspend,
+        .resume = sh_mobile_lcdc_resume,
+};
+
 static int sh_mobile_lcdc_remove(struct platform_device *pdev);
 
 static int __init sh_mobile_lcdc_probe(struct platform_device *pdev)
@@ -707,6 +757,7 @@ static int __init sh_mobile_lcdc_probe(struct platform_device *pdev)
                         dev_err(&pdev->dev, "unsupported interface type\n");
                         goto err1;
                 }
+                init_waitqueue_head(&priv->ch[i].frame_end_wait);
 
                 switch (pdata->ch[i].chan) {
                 case LCDC_CHAN_MAINLCD:
@@ -860,6 +911,7 @@ static struct platform_driver sh_mobile_lcdc_driver = {
         .driver         = {
                 .name           = "sh_mobile_lcdc_fb",
                 .owner          = THIS_MODULE,
+                .pm             = &sh_mobile_lcdc_dev_pm_ops,
         },
         .probe          = sh_mobile_lcdc_probe,
         .remove         = sh_mobile_lcdc_remove,