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>
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@ -2336,6 +2336,7 @@ config FB_MX3
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select FB_CFB_FILLRECT
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select FB_CFB_COPYAREA
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select FB_CFB_IMAGEBLIT
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select BACKLIGHT_CLASS_DEVICE
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default y
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help
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This is a framebuffer device for the i.MX31 LCD Controller. So
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@ -27,6 +27,7 @@
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#include <linux/clk.h>
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#include <linux/mutex.h>
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#include <linux/dma/ipu-dma.h>
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#include <linux/backlight.h>
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#include <linux/platform_data/dma-imx.h>
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#include <linux/platform_data/video-mx3fb.h>
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@ -241,6 +242,7 @@ struct mx3fb_data {
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void __iomem *reg_base;
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spinlock_t lock;
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struct device *dev;
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struct backlight_device *bl;
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uint32_t h_start_width;
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uint32_t v_start_width;
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@ -271,6 +273,71 @@ struct mx3fb_info {
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struct fb_var_screeninfo cur_var; /* current var info */
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};
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static void sdc_set_brightness(struct mx3fb_data *mx3fb, uint8_t value);
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static u32 sdc_get_brightness(struct mx3fb_data *mx3fb);
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static int mx3fb_bl_get_brightness(struct backlight_device *bl)
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{
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struct mx3fb_data *fbd = bl_get_data(bl);
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return sdc_get_brightness(fbd);
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}
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static int mx3fb_bl_update_status(struct backlight_device *bl)
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{
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struct mx3fb_data *fbd = bl_get_data(bl);
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int brightness = bl->props.brightness;
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if (bl->props.power != FB_BLANK_UNBLANK)
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brightness = 0;
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if (bl->props.fb_blank != FB_BLANK_UNBLANK)
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brightness = 0;
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fbd->backlight_level = (fbd->backlight_level & ~0xFF) | brightness;
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sdc_set_brightness(fbd, fbd->backlight_level);
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return 0;
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}
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static const struct backlight_ops mx3fb_lcdc_bl_ops = {
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.update_status = mx3fb_bl_update_status,
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.get_brightness = mx3fb_bl_get_brightness,
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};
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static void mx3fb_init_backlight(struct mx3fb_data *fbd)
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{
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struct backlight_properties props;
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struct backlight_device *bl;
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if (fbd->bl)
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return;
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memset(&props, 0, sizeof(struct backlight_properties));
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props.max_brightness = 0xff;
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props.type = BACKLIGHT_RAW;
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sdc_set_brightness(fbd, fbd->backlight_level);
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bl = backlight_device_register("mx3fb-bl", fbd->dev, fbd,
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&mx3fb_lcdc_bl_ops, &props);
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if (IS_ERR(bl)) {
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dev_err(fbd->dev, "error %ld on backlight register\n",
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PTR_ERR(bl));
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return;
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}
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fbd->bl = bl;
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bl->props.power = FB_BLANK_UNBLANK;
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bl->props.fb_blank = FB_BLANK_UNBLANK;
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bl->props.brightness = mx3fb_bl_get_brightness(bl);
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}
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static void mx3fb_exit_backlight(struct mx3fb_data *fbd)
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{
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if (fbd->bl)
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backlight_device_unregister(fbd->bl);
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}
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static void mx3fb_dma_done(void *);
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/* Used fb-mode and bpp. Can be set on kernel command line, therefore file-static. */
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@ -628,6 +695,16 @@ static int sdc_set_global_alpha(struct mx3fb_data *mx3fb, bool enable, uint8_t a
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return 0;
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}
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static u32 sdc_get_brightness(struct mx3fb_data *mx3fb)
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{
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u32 brightness;
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brightness = mx3fb_read_reg(mx3fb, SDC_PWM_CTRL);
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brightness = (brightness >> 16) & 0xFF;
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return brightness;
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}
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static void sdc_set_brightness(struct mx3fb_data *mx3fb, uint8_t value)
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{
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dev_dbg(mx3fb->dev, "%s: value = %d\n", __func__, value);
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@ -1534,6 +1611,8 @@ static int mx3fb_probe(struct platform_device *pdev)
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if (ret < 0)
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goto eisdc0;
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mx3fb_init_backlight(mx3fb);
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return 0;
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eisdc0:
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@ -1556,6 +1635,8 @@ static int mx3fb_remove(struct platform_device *dev)
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chan = &mx3_fbi->idmac_channel->dma_chan;
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release_fbi(fbi);
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mx3fb_exit_backlight(mx3fb);
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dma_release_channel(chan);
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dmaengine_put();
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