Re: [PATCH] video: mx3fb: Add backlight support

[Alexander Stein <alexander.stein@systec-electronic.com>]

Any feedback on this?

Alexander

On Thursday 03 April 2014 09:37:55, Alexander Stein wrote:
> Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
> ---
>  drivers/video/mx3fb.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 98 insertions(+)
> 
> diff --git a/drivers/video/mx3fb.c b/drivers/video/mx3fb.c
> index 142e860..10a7244 100644
> --- a/drivers/video/mx3fb.c
> +++ b/drivers/video/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>
> @@ -34,6 +35,12 @@
>  #include <asm/io.h>
>  #include <asm/uaccess.h>
>  
> +#if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
> +	(defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE) && \
> +		defined(CONFIG_MX3FB_MODULE))
> +#define PWM_BACKLIGHT_AVAILABLE
> +#endif
> +
>  #define MX3FB_NAME		"mx3_sdc_fb"
>  
>  #define MX3FB_REG_OFFSET	0xB4
> @@ -242,6 +249,10 @@ struct mx3fb_data {
>  	spinlock_t		lock;
>  	struct device		*dev;
>  
> +#ifdef PWM_BACKLIGHT_AVAILABLE
> +	struct backlight_device	*bl;
> +#endif
> +
>  	uint32_t		h_start_width;
>  	uint32_t		v_start_width;
>  	enum disp_data_mapping	disp_data_fmt;
> @@ -271,6 +282,74 @@ struct mx3fb_info {
>  	struct fb_var_screeninfo	cur_var; /* current var info */
>  };
>  
> +static void sdc_set_brightness(struct mx3fb_data *mx3fb, uint8_t value);
> +
> +#ifdef PWM_BACKLIGHT_AVAILABLE
> +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);
> +}
> +#endif
> +
>  static void mx3fb_dma_done(void *);
>  
>  /* Used fb-mode and bpp. Can be set on kernel command line, therefore file-static. */
> @@ -628,6 +707,18 @@ static int sdc_set_global_alpha(struct mx3fb_data *mx3fb, bool enable, uint8_t a
>  	return 0;
>  }
>  
> +#ifdef PWM_BACKLIGHT_AVAILABLE
> +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;
> +}
> +#endif
> +
>  static void sdc_set_brightness(struct mx3fb_data *mx3fb, uint8_t value)
>  {
>  	dev_dbg(mx3fb->dev, "%s: value = %d\n", __func__, value);
> @@ -1534,6 +1625,9 @@ static int mx3fb_probe(struct platform_device *pdev)
>  	if (ret < 0)
>  		goto eisdc0;
>  
> +#ifdef PWM_BACKLIGHT_AVAILABLE
> +	mx3fb_init_backlight(mx3fb);
> +#endif
>  	return 0;
>  
>  eisdc0:
> @@ -1557,6 +1651,10 @@ static int mx3fb_remove(struct platform_device *dev)
>  	chan = &mx3_fbi->idmac_channel->dma_chan;
>  	release_fbi(fbi);
>  
> +#ifdef PWM_BACKLIGHT_AVAILABLE
> +	mx3fb_exit_backlight(mx3fb);
> +#endif
> +
>  	dma_release_channel(chan);
>  	dmaengine_put();
>  
> 

-- 
Dipl.-Inf. Alexander Stein

SYS TEC electronic GmbH
Am Windrad 2
08468 Heinsdorfergrund
Tel.: 03765 38600-1156
Fax: 03765 38600-4100
Email: alexander.stein@systec-electronic.com
Website: www.systec-electronic.com
 
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