fbdev: sh_mobile_lcdcfb: add backlight support

Support for backlight devices controlled through board-specific
routines. Backlights can be defined per-channel and follow fbdev
directives to switch off as the LCD blanks or is turned on/off.

Signed-off-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/video/sh_mobile_lcdcfb.c b/drivers/video/sh_mobile_lcdcfb.c
index bf12e53aed5c..e040e46d7d91 100644
--- a/drivers/video/sh_mobile_lcdcfb.c
+++ b/drivers/video/sh_mobile_lcdcfb.c
@@ -21,6 +21,8 @@
 #include <linux/ioctl.h>
 #include <linux/slab.h>
 #include <linux/console.h>
+#include <linux/backlight.h>
+#include <linux/gpio.h>
 #include <video/sh_mobile_lcdc.h>
 #include <asm/atomic.h>
 
@@ -618,6 +620,11 @@ static int sh_mobile_lcdc_start(struct sh_mobile_lcdc_priv *priv)
                         board_cfg->display_on(board_cfg->board_data, ch->info);
                         module_put(board_cfg->owner);
                 }
+
+                if (ch->bl) {
+                        ch->bl->props.power = FB_BLANK_UNBLANK;
+                        backlight_update_status(ch->bl);
+                }
         }
 
         return 0;
@@ -648,6 +655,11 @@ static void sh_mobile_lcdc_stop(struct sh_mobile_lcdc_priv *priv)
                         sh_mobile_lcdc_clk_on(priv);
                 }
 
+                if (ch->bl) {
+                        ch->bl->props.power = FB_BLANK_POWERDOWN;
+                        backlight_update_status(ch->bl);
+                }
+
                 board_cfg = &ch->cfg.board_cfg;
                 if (try_module_get(board_cfg->owner) && board_cfg->display_off) {
                         board_cfg->display_off(board_cfg->board_data);
@@ -980,6 +992,64 @@ static struct fb_ops sh_mobile_lcdc_ops = {
         .fb_check_var   = sh_mobile_check_var,
 };
 
+static int sh_mobile_lcdc_update_bl(struct backlight_device *bdev)
+{
+        struct sh_mobile_lcdc_chan *ch = bl_get_data(bdev);
+        struct sh_mobile_lcdc_board_cfg *cfg = &ch->cfg.board_cfg;
+        int brightness = bdev->props.brightness;
+
+        if (bdev->props.power != FB_BLANK_UNBLANK ||
+            bdev->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
+                brightness = 0;
+
+        return cfg->set_brightness(cfg->board_data, brightness);
+}
+
+static int sh_mobile_lcdc_get_brightness(struct backlight_device *bdev)
+{
+        struct sh_mobile_lcdc_chan *ch = bl_get_data(bdev);
+        struct sh_mobile_lcdc_board_cfg *cfg = &ch->cfg.board_cfg;
+
+        return cfg->get_brightness(cfg->board_data);
+}
+
+static int sh_mobile_lcdc_check_fb(struct backlight_device *bdev,
+                                   struct fb_info *info)
+{
+        return (info->bl_dev == bdev);
+}
+
+static struct backlight_ops sh_mobile_lcdc_bl_ops = {
+        .options        = BL_CORE_SUSPENDRESUME,
+        .update_status  = sh_mobile_lcdc_update_bl,
+        .get_brightness = sh_mobile_lcdc_get_brightness,
+        .check_fb       = sh_mobile_lcdc_check_fb,
+};
+
+static struct backlight_device *sh_mobile_lcdc_bl_probe(struct device *parent,
+                                               struct sh_mobile_lcdc_chan *ch)
+{
+        struct backlight_device *bl;
+
+        bl = backlight_device_register(ch->cfg.bl_info.name, parent, ch,
+                                       &sh_mobile_lcdc_bl_ops, NULL);
+        if (!bl) {
+                dev_err(parent, "unable to register backlight device\n");
+                return NULL;
+        }
+
+        bl->props.max_brightness = ch->cfg.bl_info.max_brightness;
+        bl->props.brightness = bl->props.max_brightness;
+        backlight_update_status(bl);
+
+        return bl;
+}
+
+static void sh_mobile_lcdc_bl_remove(struct backlight_device *bdev)
+{
+        backlight_device_unregister(bdev);
+}
+
 static int sh_mobile_lcdc_set_bpp(struct fb_var_screeninfo *var, int bpp)
 {
         switch (bpp) {
@@ -1198,6 +1268,10 @@ static int __devinit sh_mobile_lcdc_probe(struct platform_device *pdev)
                 init_completion(&ch->vsync_completion);
                 ch->pan_offset = 0;
 
+                /* probe the backlight is there is one defined */
+                if (ch->cfg.bl_info.max_brightness)
+                        ch->bl = sh_mobile_lcdc_bl_probe(&pdev->dev, ch);
+
                 switch (pdata->ch[i].chan) {
                 case LCDC_CHAN_MAINLCD:
                         ch->enabled = 1 << 1;
@@ -1345,6 +1419,8 @@ static int __devinit sh_mobile_lcdc_probe(struct platform_device *pdev)
                         }
                 }
 
+                info->bl_dev = ch->bl;
+
                 error = register_framebuffer(info);
                 if (error < 0)
                         goto err1;
@@ -1404,6 +1480,11 @@ static int sh_mobile_lcdc_remove(struct platform_device *pdev)
                 framebuffer_release(info);
         }
 
+        for (i = 0; i < ARRAY_SIZE(priv->ch); i++) {
+                if (priv->ch[i].bl)
+                        sh_mobile_lcdc_bl_remove(priv->ch[i].bl);
+        }
+
         if (priv->dot_clk)
                 clk_put(priv->dot_clk);