diff options
author | Alexander Stein <alexander.stein@systec-electronic.com> | 2014-05-12 08:34:14 +0200 |
---|---|---|
committer | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2014-05-16 11:58:39 +0300 |
commit | 7edaa761ee81bf28804e45d405f163dea26bfa7f (patch) | |
tree | dc39e9ff7db5007a2b8a7daeeaacf436238ebd2f /drivers | |
parent | 7ceb1892c04c6c27765cc6139d6057b72dc86e95 (diff) |
video: mx3fb: Add backlight control support
This patch add backlight control support to allow dimming the backlight
using the internal PWM. Currently the brightness is set fixed to a
maximum of 255.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/video/fbdev/Kconfig | 1 | ||||
-rw-r--r-- | drivers/video/fbdev/mx3fb.c | 81 |
2 files changed, 82 insertions, 0 deletions
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig index 96f0f42d53bc..59c98bfd5a8a 100644 --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -2336,6 +2336,7 @@ config FB_MX3 select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT + select BACKLIGHT_CLASS_DEVICE default y help This is a framebuffer device for the i.MX31 LCD Controller. So diff --git a/drivers/video/fbdev/mx3fb.c b/drivers/video/fbdev/mx3fb.c index ee95de80a487..c645a0a0c341 100644 --- a/drivers/video/fbdev/mx3fb.c +++ b/drivers/video/fbdev/mx3fb.c @@ -27,6 +27,7 @@ #include <linux/clk.h> #include <linux/mutex.h> #include <linux/dma/ipu-dma.h> +#include <linux/backlight.h> #include <linux/platform_data/dma-imx.h> #include <linux/platform_data/video-mx3fb.h> @@ -241,6 +242,7 @@ struct mx3fb_data { void __iomem *reg_base; spinlock_t lock; struct device *dev; + struct backlight_device *bl; uint32_t h_start_width; uint32_t v_start_width; @@ -271,6 +273,71 @@ struct mx3fb_info { struct fb_var_screeninfo cur_var; /* current var info */ }; +static void sdc_set_brightness(struct mx3fb_data *mx3fb, uint8_t value); +static u32 sdc_get_brightness(struct mx3fb_data *mx3fb); + +static int mx3fb_bl_get_brightness(struct backlight_device *bl) +{ + struct mx3fb_data *fbd = bl_get_data(bl); + + return sdc_get_brightness(fbd); +} + +static int mx3fb_bl_update_status(struct backlight_device *bl) +{ + struct mx3fb_data *fbd = bl_get_data(bl); + int brightness = bl->props.brightness; + + if (bl->props.power != FB_BLANK_UNBLANK) + brightness = 0; + if (bl->props.fb_blank != FB_BLANK_UNBLANK) + brightness = 0; + + fbd->backlight_level = (fbd->backlight_level & ~0xFF) | brightness; + + sdc_set_brightness(fbd, fbd->backlight_level); + + return 0; +} + +static const struct backlight_ops mx3fb_lcdc_bl_ops = { + .update_status = mx3fb_bl_update_status, + .get_brightness = mx3fb_bl_get_brightness, +}; + +static void mx3fb_init_backlight(struct mx3fb_data *fbd) +{ + struct backlight_properties props; + struct backlight_device *bl; + + if (fbd->bl) + return; + + memset(&props, 0, sizeof(struct backlight_properties)); + props.max_brightness = 0xff; + props.type = BACKLIGHT_RAW; + sdc_set_brightness(fbd, fbd->backlight_level); + + bl = backlight_device_register("mx3fb-bl", fbd->dev, fbd, + &mx3fb_lcdc_bl_ops, &props); + if (IS_ERR(bl)) { + dev_err(fbd->dev, "error %ld on backlight register\n", + PTR_ERR(bl)); + return; + } + + fbd->bl = bl; + bl->props.power = FB_BLANK_UNBLANK; + bl->props.fb_blank = FB_BLANK_UNBLANK; + bl->props.brightness = mx3fb_bl_get_brightness(bl); +} + +static void mx3fb_exit_backlight(struct mx3fb_data *fbd) +{ + if (fbd->bl) + backlight_device_unregister(fbd->bl); +} + static void mx3fb_dma_done(void *); /* Used fb-mode and bpp. Can be set on kernel command line, therefore file-static. */ @@ -628,6 +695,16 @@ static int sdc_set_global_alpha(struct mx3fb_data *mx3fb, bool enable, uint8_t a return 0; } +static u32 sdc_get_brightness(struct mx3fb_data *mx3fb) +{ + u32 brightness; + + brightness = mx3fb_read_reg(mx3fb, SDC_PWM_CTRL); + brightness = (brightness >> 16) & 0xFF; + + return brightness; +} + static void sdc_set_brightness(struct mx3fb_data *mx3fb, uint8_t value) { dev_dbg(mx3fb->dev, "%s: value = %d\n", __func__, value); @@ -1534,6 +1611,8 @@ static int mx3fb_probe(struct platform_device *pdev) if (ret < 0) goto eisdc0; + mx3fb_init_backlight(mx3fb); + return 0; eisdc0: @@ -1556,6 +1635,8 @@ static int mx3fb_remove(struct platform_device *dev) chan = &mx3_fbi->idmac_channel->dma_chan; release_fbi(fbi); + mx3fb_exit_backlight(mx3fb); + dma_release_channel(chan); dmaengine_put(); |