1 // SPDX-License-Identifier: GPL-2.0+
11 #include <backlight.h>
13 #include <asm/gpio.h>
17  * Private information for the PWM backlight
19  * If @num_levels is 0 then the levels are simple values with the backlight
21  * Otherwise the levels are an index into @levels (0..n-1).
23  * @reg: Regulator to enable to turn the backlight on (NULL if none)
24  * @enable, GPIO to set to enable the backlight (can be missing)
25  * @pwm: PWM to use to change the backlight brightness
27  * @period_ns: Period of the backlight in nanoseconds
28  * @levels: Levels for the backlight, or NULL if not using indexed levels
30  * @cur_level: Current level for the backlight (index or value)
31  * @default_level: Default level for the backlight (index or value)
32  * @min_level: Minimum level of the backlight (full off)
33  * @min_level: Maximum level of the backlight (full on)
34  * @enabled: true if backlight is enabled
56 	duty_cycle = priv->period_ns * (priv->cur_level - priv->min_level) /  in set_pwm()
57 		(priv->max_level - priv->min_level + 1);  in set_pwm()
58 	ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,  in set_pwm()
71 		if (priv->reg) {  in enable_sequence()
75 			plat = dev_get_uclass_platdata(priv->reg);  in enable_sequence()
77 				  dev->name, priv->reg->name, plat->name);  in enable_sequence()
78 			ret = regulator_set_enable(priv->reg, true);  in enable_sequence()
81 					  dev->name);  in enable_sequence()
89 		dm_gpio_set_value(&priv->enable, 1);  in enable_sequence()
107 	ret = pwm_set_enable(priv->pwm, priv->channel, true);  in pwm_backlight_enable()
113 	priv->enabled = true;  in pwm_backlight_enable()
125 	if (!priv->enabled) {  in pwm_backlight_set_brightness()
135 		level = priv->default_level;  in pwm_backlight_set_brightness()
137 		if (priv->levels) {  in pwm_backlight_set_brightness()
138 			level = priv->levels[percent * (priv->num_levels - 1)  in pwm_backlight_set_brightness()
141 			level = priv->min_level +  in pwm_backlight_set_brightness()
142 				(priv->max_level - priv->min_level) *  in pwm_backlight_set_brightness()
146 	priv->cur_level = level;  in pwm_backlight_set_brightness()
151 	if (!priv->enabled) {  in pwm_backlight_set_brightness()
155 		priv->enabled = true;  in pwm_backlight_set_brightness()
158 		dm_gpio_set_value(&priv->enable, 0);  in pwm_backlight_set_brightness()
159 		if (priv->reg) {  in pwm_backlight_set_brightness()
160 			ret = regulator_set_enable(priv->reg, false);  in pwm_backlight_set_brightness()
164 		priv->enabled = false;  in pwm_backlight_set_brightness()
179 					   "power-supply", &priv->reg);  in pwm_backlight_ofdata_to_platdata()
182 	ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable,  in pwm_backlight_ofdata_to_platdata()
185 		log_debug("Warning: cannot get enable GPIO: ret=%d\n", ret);  in pwm_backlight_ofdata_to_platdata()
186 		if (ret != -ENOENT)  in pwm_backlight_ofdata_to_platdata()
189 	ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0,  in pwm_backlight_ofdata_to_platdata()
196 	ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm);  in pwm_backlight_ofdata_to_platdata()
202 		return log_msg_ret("Not enough arguments to pwm\n", -EINVAL);  in pwm_backlight_ofdata_to_platdata()
203 	priv->channel = args.args[0];  in pwm_backlight_ofdata_to_platdata()
204 	priv->period_ns = args.args[1];  in pwm_backlight_ofdata_to_platdata()
206 	index = dev_read_u32_default(dev, "default-brightness-level", 255);  in pwm_backlight_ofdata_to_platdata()
207 	cell = dev_read_prop(dev, "brightness-levels", &len);  in pwm_backlight_ofdata_to_platdata()
210 		priv->levels = malloc(len);  in pwm_backlight_ofdata_to_platdata()
211 		if (!priv->levels)  in pwm_backlight_ofdata_to_platdata()
212 			return log_ret(-ENOMEM);  in pwm_backlight_ofdata_to_platdata()
213 		dev_read_u32_array(dev, "brightness-levels", priv->levels,  in pwm_backlight_ofdata_to_platdata()
215 		priv->num_levels = count;  in pwm_backlight_ofdata_to_platdata()
216 		priv->default_level = priv->levels[index];  in pwm_backlight_ofdata_to_platdata()
217 		priv->max_level = priv->levels[count - 1];  in pwm_backlight_ofdata_to_platdata()
219 		priv->default_level = index;  in pwm_backlight_ofdata_to_platdata()
220 		priv->max_level = 255;  in pwm_backlight_ofdata_to_platdata()
222 	priv->cur_level = priv->default_level;  in pwm_backlight_ofdata_to_platdata()
240 	{ .compatible = "pwm-backlight" },