Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7edaa761 authored by Alexander Stein's avatar Alexander Stein Committed by Tomi Valkeinen
Browse files

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: default avatarAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
parent 7ceb1892

drivers/video/fbdev/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/video/fbdev/mx3fb.c

+81 −0
Original line number Diff line number Diff line
@@ -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();