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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Backlight driver for Marvell Semiconductor 88PM86064 *5 * Copyright (C) 2009 Marvell International Ltd.6 * Haojian Zhuang <haojian.zhuang@marvell.com>7 */8 9#include <linux/init.h>10#include <linux/kernel.h>11#include <linux/of.h>12#include <linux/platform_device.h>13#include <linux/slab.h>14#include <linux/fb.h>15#include <linux/i2c.h>16#include <linux/backlight.h>17#include <linux/mfd/88pm860x.h>18#include <linux/module.h>19 20#define MAX_BRIGHTNESS (0xFF)21#define MIN_BRIGHTNESS (0)22 23#define CURRENT_BITMASK (0x1F << 1)24 25struct pm860x_backlight_data {26 struct pm860x_chip *chip;27 struct i2c_client *i2c;28 int current_brightness;29 int port;30 int pwm;31 int iset;32 int reg_duty_cycle;33 int reg_always_on;34 int reg_current;35};36 37static int backlight_power_set(struct pm860x_chip *chip, int port,38 int on)39{40 int ret = -EINVAL;41 42 switch (port) {43 case 0:44 ret = on ? pm8606_osc_enable(chip, WLED1_DUTY) :45 pm8606_osc_disable(chip, WLED1_DUTY);46 break;47 case 1:48 ret = on ? pm8606_osc_enable(chip, WLED2_DUTY) :49 pm8606_osc_disable(chip, WLED2_DUTY);50 break;51 case 2:52 ret = on ? pm8606_osc_enable(chip, WLED3_DUTY) :53 pm8606_osc_disable(chip, WLED3_DUTY);54 break;55 }56 return ret;57}58 59static int pm860x_backlight_set(struct backlight_device *bl, int brightness)60{61 struct pm860x_backlight_data *data = bl_get_data(bl);62 struct pm860x_chip *chip = data->chip;63 unsigned char value;64 int ret;65 66 if (brightness > MAX_BRIGHTNESS)67 value = MAX_BRIGHTNESS;68 else69 value = brightness;70 71 if (brightness)72 backlight_power_set(chip, data->port, 1);73 74 ret = pm860x_reg_write(data->i2c, data->reg_duty_cycle, value);75 if (ret < 0)76 goto out;77 78 if ((data->current_brightness == 0) && brightness) {79 if (data->iset) {80 ret = pm860x_set_bits(data->i2c, data->reg_current,81 CURRENT_BITMASK, data->iset);82 if (ret < 0)83 goto out;84 }85 if (data->pwm) {86 ret = pm860x_set_bits(data->i2c, PM8606_PWM,87 PM8606_PWM_FREQ_MASK, data->pwm);88 if (ret < 0)89 goto out;90 }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);95 }96 } else {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);101 } else {102 /* clear WLED_ON bit since it's not 100% */103 ret = pm860x_set_bits(data->i2c, data->reg_always_on,104 PM8606_WLED_ON, 0);105 }106 }107 if (ret < 0)108 goto out;109 110 if (brightness == 0)111 backlight_power_set(chip, data->port, 0);112 113 dev_dbg(chip->dev, "set brightness %d\n", value);114 data->current_brightness = value;115 return 0;116out:117 dev_dbg(chip->dev, "set brightness %d failure with return value: %d\n",118 value, ret);119 return ret;120}121 122static int pm860x_backlight_update_status(struct backlight_device *bl)123{124 return pm860x_backlight_set(bl, backlight_get_brightness(bl));125}126 127static int pm860x_backlight_get_brightness(struct backlight_device *bl)128{129 struct pm860x_backlight_data *data = bl_get_data(bl);130 struct pm860x_chip *chip = data->chip;131 int ret;132 133 ret = pm860x_reg_read(data->i2c, data->reg_duty_cycle);134 if (ret < 0)135 goto out;136 data->current_brightness = ret;137 dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);138 return data->current_brightness;139out:140 return -EINVAL;141}142 143static const struct backlight_ops pm860x_backlight_ops = {144 .options = BL_CORE_SUSPENDRESUME,145 .update_status = pm860x_backlight_update_status,146 .get_brightness = pm860x_backlight_get_brightness,147};148 149#ifdef CONFIG_OF150static int pm860x_backlight_dt_init(struct platform_device *pdev,151 struct pm860x_backlight_data *data,152 char *name)153{154 struct device_node *nproot, *np;155 int iset = 0;156 157 nproot = of_get_child_by_name(pdev->dev.parent->of_node, "backlights");158 if (!nproot) {159 dev_err(&pdev->dev, "failed to find backlights node\n");160 return -ENODEV;161 }162 for_each_child_of_node(nproot, np) {163 if (of_node_name_eq(np, name)) {164 of_property_read_u32(np, "marvell,88pm860x-iset",165 &iset);166 data->iset = PM8606_WLED_CURRENT(iset);167 of_property_read_u32(np, "marvell,88pm860x-pwm",168 &data->pwm);169 of_node_put(np);170 break;171 }172 }173 of_node_put(nproot);174 return 0;175}176#else177#define pm860x_backlight_dt_init(x, y, z) (-1)178#endif179 180static int pm860x_backlight_probe(struct platform_device *pdev)181{182 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);183 struct pm860x_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);184 struct pm860x_backlight_data *data;185 struct backlight_device *bl;186 struct resource *res;187 struct backlight_properties props;188 char name[MFD_NAME_SIZE];189 int ret = 0;190 191 data = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_backlight_data),192 GFP_KERNEL);193 if (data == NULL)194 return -ENOMEM;195 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "duty cycle");196 if (!res) {197 dev_err(&pdev->dev, "No REG resource for duty cycle\n");198 return -ENXIO;199 }200 data->reg_duty_cycle = res->start;201 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "always on");202 if (!res) {203 dev_err(&pdev->dev, "No REG resource for always on\n");204 return -ENXIO;205 }206 data->reg_always_on = res->start;207 res = platform_get_resource_byname(pdev, IORESOURCE_REG, "current");208 if (!res) {209 dev_err(&pdev->dev, "No REG resource for current\n");210 return -ENXIO;211 }212 data->reg_current = res->start;213 214 memset(name, 0, MFD_NAME_SIZE);215 sprintf(name, "backlight-%d", pdev->id);216 data->port = pdev->id;217 data->chip = chip;218 data->i2c = (chip->id == CHIP_PM8606) ? chip->client : chip->companion;219 data->current_brightness = MAX_BRIGHTNESS;220 if (pm860x_backlight_dt_init(pdev, data, name)) {221 if (pdata) {222 data->pwm = pdata->pwm;223 data->iset = pdata->iset;224 }225 }226 227 memset(&props, 0, sizeof(struct backlight_properties));228 props.type = BACKLIGHT_RAW;229 props.max_brightness = MAX_BRIGHTNESS;230 bl = devm_backlight_device_register(&pdev->dev, name, &pdev->dev, data,231 &pm860x_backlight_ops, &props);232 if (IS_ERR(bl)) {233 dev_err(&pdev->dev, "failed to register backlight\n");234 return PTR_ERR(bl);235 }236 bl->props.brightness = MAX_BRIGHTNESS;237 238 platform_set_drvdata(pdev, bl);239 240 /* read current backlight */241 ret = pm860x_backlight_get_brightness(bl);242 if (ret < 0)243 return ret;244 245 backlight_update_status(bl);246 return 0;247}248 249static struct platform_driver pm860x_backlight_driver = {250 .driver = {251 .name = "88pm860x-backlight",252 },253 .probe = pm860x_backlight_probe,254};255 256module_platform_driver(pm860x_backlight_driver);257 258MODULE_DESCRIPTION("Backlight Driver for Marvell Semiconductor 88PM8606");259MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");260MODULE_LICENSE("GPL");261MODULE_ALIAS("platform:88pm860x-backlight");262