fbdev: ssd1307fb: add backlight controls for setting the contrast (6ed5e2db) · Commits · 戴 / test

drivers/video/fbdev/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -2478,6 +2478,7 @@ config FB_SSD1307
		select FB_SYS_IMAGEBLIT
		select FB_DEFERRED_IO
		select PWM
		select FB_BACKLIGHT
		help
		This driver implements support for the Solomon SSD1307
		OLED controller over I2C.

drivers/video/fbdev/ssd1307fb.c

+58 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@
		*/

		#include <linux/module.h>
		#include <linux/backlight.h>
		#include <linux/kernel.h>
		#include <linux/i2c.h>
		#include <linux/fb.h>
		@@ -38,6 +39,8 @@
		#define SSD1307FB_SET_COM_PINS_CONFIG 0xda
		#define SSD1307FB_SET_VCOMH 0xdb

		#define MAX_CONTRAST 255

		#define REFRESHRATE 1

		static u_int refreshrate = REFRESHRATE;
		@@ -424,6 +427,43 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
		return 0;
		}

		static int ssd1307fb_update_bl(struct backlight_device *bdev)
		{
		struct ssd1307fb_par *par = bl_get_data(bdev);
		int ret;
		int brightness = bdev->props.brightness;

		par->contrast = brightness;

		ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
		if (ret < 0)
		return ret;
		ret = ssd1307fb_write_cmd(par->client, par->contrast);
		if (ret < 0)
		return ret;
		return 0;
		}

		static int ssd1307fb_get_brightness(struct backlight_device *bdev)
		{
		struct ssd1307fb_par *par = bl_get_data(bdev);

		return par->contrast;
		}

		static int ssd1307fb_check_fb(struct backlight_device *bdev,
		struct fb_info *info)
		{
		return (info->bl_dev == bdev);
		}

		static const struct backlight_ops ssd1307fb_bl_ops = {
		.options = BL_CORE_SUSPENDRESUME,
		.update_status = ssd1307fb_update_bl,
		.get_brightness = ssd1307fb_get_brightness,
		.check_fb = ssd1307fb_check_fb,
		};

		static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo = {
		.default_vcomh = 0x34,
		.default_dclk_div = 1,
		@@ -464,6 +504,8 @@ MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
		static int ssd1307fb_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct backlight_device *bl;
		char bl_name[12];
		struct fb_info *info;
		struct device_node *node = client->dev.of_node;
		struct fb_deferred_io *ssd1307fb_defio;
		@@ -599,10 +641,24 @@ static int ssd1307fb_probe(struct i2c_client *client,
		goto panel_init_error;
		}

		snprintf(bl_name, sizeof(bl_name), "ssd1307fb%d", info->node);
		bl = backlight_device_register(bl_name, &client->dev, par,
		&ssd1307fb_bl_ops, NULL);
		bl->props.brightness = par->contrast;
		bl->props.max_brightness = MAX_CONTRAST;
		info->bl_dev = bl;

		if (IS_ERR(bl)) {
		dev_err(&client->dev, "unable to register backlight device: %ld\n",
		PTR_ERR(bl));
		goto bl_init_error;
		}
		dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);

		return 0;

		bl_init_error:
		unregister_framebuffer(info);
		panel_init_error:
		if (par->device_info->need_pwm) {
		pwm_disable(par->pwm);
		@@ -622,6 +678,8 @@ static int ssd1307fb_remove(struct i2c_client *client)

		ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);

		backlight_device_unregister(info->bl_dev);

		unregister_framebuffer(info);
		if (par->device_info->need_pwm) {
		pwm_disable(par->pwm);

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