1 // SPDX-License-Identifier: GPL-2.0-only
3 * Backlight driver for Marvell Semiconductor 88PM8606
5 * Copyright (C) 2009 Marvell International Ltd.
6 * Haojian Zhuang <haojian.zhuang@marvell.com>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
12 #include <linux/platform_device.h>
13 #include <linux/slab.h>
15 #include <linux/i2c.h>
16 #include <linux/backlight.h>
17 #include <linux/mfd/88pm860x.h>
18 #include <linux/module.h>
20 #define MAX_BRIGHTNESS (0xFF)
21 #define MIN_BRIGHTNESS (0)
23 #define CURRENT_BITMASK (0x1F << 1)
25 struct pm860x_backlight_data {
26 struct pm860x_chip *chip;
27 struct i2c_client *i2c;
28 int current_brightness;
37 static int backlight_power_set(struct pm860x_chip *chip, int port,
44 ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :
45 pm8606_osc_disable(chip, WLED1_DUTY);
48 ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :
49 pm8606_osc_disable(chip, WLED2_DUTY);
52 ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :
53 pm8606_osc_disable(chip, WLED3_DUTY);
59 static int pm860x_backlight_set(struct backlight_device *bl, int brightness)
61 struct pm860x_backlight_data *data = bl_get_data(bl);
62 struct pm860x_chip *chip = data->chip;
66 if (brightness > MAX_BRIGHTNESS)
67 value = MAX_BRIGHTNESS;
72 backlight_power_set(chip, data->port, 1);
74 ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);
78 if ((data->current_brightness == 0) && brightness) {
80 ret = pm860x_set_bits(data->i2c, data->reg_current,
81 CURRENT_BITMASK, data->iset);
86 ret = pm860x_set_bits(data->i2c, PM8606_PWM,
87 PM8606_PWM_FREQ_MASK, data->pwm);
91 if (brightness == MAX_BRIGHTNESS) {
92 /* set WLED_ON bit as 100% */
93 ret = pm860x_set_bits(data->i2c, data->reg_always_on,
94 PM8606_WLED_ON, PM8606_WLED_ON);
97 if (brightness == MAX_BRIGHTNESS) {
98 /* set WLED_ON bit as 100% */
99 ret = pm860x_set_bits(data->i2c, data->reg_always_on,
100 PM8606_WLED_ON, PM8606_WLED_ON);
102 /* clear WLED_ON bit since it's not 100% */
103 ret = pm860x_set_bits(data->i2c, data->reg_always_on,
111 backlight_power_set(chip, data->port, 0);
113 dev_dbg(chip->dev, "set brightness %d\n", value);
114 data->current_brightness = value;
117 dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",
122 static int pm860x_backlight_update_status(struct backlight_device *bl)
124 int brightness = bl->props.brightness;
126 if (bl->props.power != FB_BLANK_UNBLANK)
129 if (bl->props.fb_blank != FB_BLANK_UNBLANK)
132 if (bl->props.state & BL_CORE_SUSPENDED)
135 return pm860x_backlight_set(bl, brightness);
138 static int pm860x_backlight_get_brightness(struct backlight_device *bl)
140 struct pm860x_backlight_data *data = bl_get_data(bl);
141 struct pm860x_chip *chip = data->chip;
144 ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);
147 data->current_brightness = ret;
148 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
149 return data->current_brightness;
154 static const struct backlight_ops pm860x_backlight_ops = {
155 .options = BL_CORE_SUSPENDRESUME,
156 .update_status = pm860x_backlight_update_status,
157 .get_brightness = pm860x_backlight_get_brightness,
161 static int pm860x_backlight_dt_init(struct platform_device *pdev,
162 struct pm860x_backlight_data *data,
165 struct device_node *nproot, *np;
168 nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");
170 dev_err(&pdev->dev, "failed to find backlights node\n");
173 for_each_child_of_node(nproot, np) {
174 if (of_node_name_eq(np, name)) {
175 of_property_read_u32(np, "marvell,88pm860x-iset",
177 data->iset = PM8606_WLED_CURRENT(iset);
178 of_property_read_u32(np, "marvell,88pm860x-pwm",
188 #define pm860x_backlight_dt_init(x, y, z) (-1)
191 static int pm860x_backlight_probe(struct platform_device *pdev)
193 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
194 struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
195 struct pm860x_backlight_data *data;
196 struct backlight_device *bl;
197 struct resource *res;
198 struct backlight_properties props;
199 char name[MFD_NAME_SIZE];
202 data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),
206 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");
208 dev_err(&pdev->dev, "No REG resource for duty cycle\n");
211 data->reg_duty_cycle = res->start;
212 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");
214 dev_err(&pdev->dev, "No REG resource for always on\n");
217 data->reg_always_on = res->start;
218 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");
220 dev_err(&pdev->dev, "No REG resource for current\n");
223 data->reg_current = res->start;
225 memset(name, 0, MFD_NAME_SIZE);
226 sprintf(name, "backlight-%d", pdev->id);
227 data->port = pdev->id;
229 data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;
230 data->current_brightness = MAX_BRIGHTNESS;
231 if (pm860x_backlight_dt_init(pdev, data, name)) {
233 data->pwm = pdata->pwm;
234 data->iset = pdata->iset;
238 memset(&props, 0, sizeof(struct backlight_properties));
239 props.type = BACKLIGHT_RAW;
240 props.max_brightness = MAX_BRIGHTNESS;
241 bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,
242 &pm860x_backlight_ops, &props);
244 dev_err(&pdev->dev, "failed to register backlight\n");
247 bl->props.brightness = MAX_BRIGHTNESS;
249 platform_set_drvdata(pdev, bl);
251 /* read current backlight */
252 ret = pm860x_backlight_get_brightness(bl);
256 backlight_update_status(bl);
260 static struct platform_driver pm860x_backlight_driver = {
262 .name = "88pm860x-backlight",
264 .probe = pm860x_backlight_probe,
267 module_platform_driver(pm860x_backlight_driver);
269 MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");
270 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
271 MODULE_LICENSE("GPL");
272 MODULE_ALIAS("platform:88pm860x-backlight");