3  * Backlight driver for the Kinetic KTD253
37 static void ktd253_backlight_set_max_ratio(struct ktd253_backlight *ktd253)  in ktd253_backlight_set_max_ratio()  argument
39 	gpiod_set_value_cansleep(ktd253->gpiod, 1);  in ktd253_backlight_set_max_ratio()
44 static int ktd253_backlight_stepdown(struct ktd253_backlight *ktd253)  in ktd253_backlight_stepdown()  argument
62 	gpiod_set_value(ktd253->gpiod, 0);  in ktd253_backlight_stepdown()
64 	gpiod_set_value(ktd253->gpiod, 1);  in ktd253_backlight_stepdown()
67 		dev_err(ktd253->dev, "PCM on backlight took too long (%llu ns)\n", ns);  in ktd253_backlight_stepdown()
76 	struct ktd253_backlight *ktd253 = bl_get_data(bl);  in ktd253_backlight_update_status()  local
79 	u16 current_ratio = ktd253->ratio;  in ktd253_backlight_update_status()
82 	dev_dbg(ktd253->dev, "new brightness/ratio: %d/32\n", brightness);  in ktd253_backlight_update_status()
91 		gpiod_set_value_cansleep(ktd253->gpiod, 0);  in ktd253_backlight_update_status()
94 		 * to actually switch the KTD253 off.  in ktd253_backlight_update_status()
97 		ktd253->ratio = 0;  in ktd253_backlight_update_status()
102 		ktd253_backlight_set_max_ratio(ktd253);  in ktd253_backlight_update_status()
112 		ret = ktd253_backlight_stepdown(ktd253);  in ktd253_backlight_update_status()
119 			gpiod_set_value_cansleep(ktd253->gpiod, 0);  in ktd253_backlight_update_status()
121 			ktd253_backlight_set_max_ratio(ktd253);  in ktd253_backlight_update_status()
130 	ktd253->ratio = current_ratio;  in ktd253_backlight_update_status()
132 	dev_dbg(ktd253->dev, "new ratio set to %d/32\n", target_ratio);  in ktd253_backlight_update_status()
146 	struct ktd253_backlight *ktd253;  in ktd253_backlight_probe()  local
151 	ktd253 = devm_kzalloc(dev, sizeof(*ktd253), GFP_KERNEL);  in ktd253_backlight_probe()
152 	if (!ktd253)  in ktd253_backlight_probe()
154 	ktd253->dev = dev;  in ktd253_backlight_probe()
174 	ktd253->gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);  in ktd253_backlight_probe()
175 	if (IS_ERR(ktd253->gpiod))  in ktd253_backlight_probe()
176 		return dev_err_probe(dev, PTR_ERR(ktd253->gpiod),  in ktd253_backlight_probe()
178 	gpiod_set_consumer_name(ktd253->gpiod, dev_name(dev));  in ktd253_backlight_probe()
182 	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ktd253,  in ktd253_backlight_probe()
198 	ktd253->bl = bl;  in ktd253_backlight_probe()
206 	{ .compatible = "kinetic,ktd253" },
214 		.name = "ktd253-backlight",
222 MODULE_DESCRIPTION("Kinetic KTD253 Backlight Driver");
224 MODULE_ALIAS("platform:ktd253-backlight");