video/backlight/da9052_bl.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Backlight Driver for Dialog DA9052 PMICs
0004  *
0005  * Copyright(c) 2012 Dialog Semiconductor Ltd.
0006  *
0007  * Author: David Dajun Chen <dchen@diasemi.com>
0008  */
0009
0010 #include <linux/backlight.h>
0011 #include <linux/delay.h>
0012 #include <linux/fb.h>
0013 #include <linux/module.h>
0014 #include <linux/platform_device.h>
0015
0016 #include <linux/mfd/da9052/da9052.h>
0017 #include <linux/mfd/da9052/reg.h>
0018
0019 #define DA9052_MAX_BRIGHTNESS       0xFF
0020
0021 enum {
0022     DA9052_WLEDS_OFF,
0023     DA9052_WLEDS_ON,
0024 };
0025
0026 enum {
0027     DA9052_TYPE_WLED1,
0028     DA9052_TYPE_WLED2,
0029     DA9052_TYPE_WLED3,
0030 };
0031
0032 static const unsigned char wled_bank[] = {
0033     DA9052_LED1_CONF_REG,
0034     DA9052_LED2_CONF_REG,
0035     DA9052_LED3_CONF_REG,
0036 };
0037
0038 struct da9052_bl {
0039     struct da9052 *da9052;
0040     uint brightness;
0041     uint state;
0042     uint led_reg;
0043 };
0044
0045 static int da9052_adjust_wled_brightness(struct da9052_bl *wleds)
0046 {
0047     unsigned char boost_en;
0048     unsigned char i_sink;
0049     int ret;
0050
0051     boost_en = 0x3F;
0052     i_sink = 0xFF;
0053     if (wleds->state == DA9052_WLEDS_OFF) {
0054         boost_en = 0x00;
0055         i_sink = 0x00;
0056     }
0057
0058     ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en);
0059     if (ret < 0)
0060         return ret;
0061
0062     ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink);
0063     if (ret < 0)
0064         return ret;
0065
0066     ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0);
0067     if (ret < 0)
0068         return ret;
0069
0070     usleep_range(10000, 11000);
0071
0072     if (wleds->brightness) {
0073         ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg],
0074                        wleds->brightness);
0075         if (ret < 0)
0076             return ret;
0077     }
0078
0079     return 0;
0080 }
0081
0082 static int da9052_backlight_update_status(struct backlight_device *bl)
0083 {
0084     int brightness = bl->props.brightness;
0085     struct da9052_bl *wleds = bl_get_data(bl);
0086
0087     wleds->brightness = brightness;
0088     wleds->state = DA9052_WLEDS_ON;
0089
0090     return da9052_adjust_wled_brightness(wleds);
0091 }
0092
0093 static int da9052_backlight_get_brightness(struct backlight_device *bl)
0094 {
0095     struct da9052_bl *wleds = bl_get_data(bl);
0096
0097     return wleds->brightness;
0098 }
0099
0100 static const struct backlight_ops da9052_backlight_ops = {
0101     .update_status = da9052_backlight_update_status,
0102     .get_brightness = da9052_backlight_get_brightness,
0103 };
0104
0105 static int da9052_backlight_probe(struct platform_device *pdev)
0106 {
0107     struct backlight_device *bl;
0108     struct backlight_properties props;
0109     struct da9052_bl *wleds;
0110
0111     wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL);
0112     if (!wleds)
0113         return -ENOMEM;
0114
0115     wleds->da9052 = dev_get_drvdata(pdev->dev.parent);
0116     wleds->brightness = 0;
0117     wleds->led_reg = platform_get_device_id(pdev)->driver_data;
0118     wleds->state = DA9052_WLEDS_OFF;
0119
0120     props.type = BACKLIGHT_RAW;
0121     props.max_brightness = DA9052_MAX_BRIGHTNESS;
0122
0123     bl = devm_backlight_device_register(&pdev->dev, pdev->name,
0124                     wleds->da9052->dev, wleds,
0125                     &da9052_backlight_ops, &props);
0126     if (IS_ERR(bl)) {
0127         dev_err(&pdev->dev, "Failed to register backlight\n");
0128         return PTR_ERR(bl);
0129     }
0130
0131     bl->props.max_brightness = DA9052_MAX_BRIGHTNESS;
0132     bl->props.brightness = 0;
0133     platform_set_drvdata(pdev, bl);
0134
0135     return da9052_adjust_wled_brightness(wleds);
0136 }
0137
0138 static int da9052_backlight_remove(struct platform_device *pdev)
0139 {
0140     struct backlight_device *bl = platform_get_drvdata(pdev);
0141     struct da9052_bl *wleds = bl_get_data(bl);
0142
0143     wleds->brightness = 0;
0144     wleds->state = DA9052_WLEDS_OFF;
0145     da9052_adjust_wled_brightness(wleds);
0146
0147     return 0;
0148 }
0149
0150 static const struct platform_device_id da9052_wled_ids[] = {
0151     {
0152         .name       = "da9052-wled1",
0153         .driver_data    = DA9052_TYPE_WLED1,
0154     },
0155     {
0156         .name       = "da9052-wled2",
0157         .driver_data    = DA9052_TYPE_WLED2,
0158     },
0159     {
0160         .name       = "da9052-wled3",
0161         .driver_data    = DA9052_TYPE_WLED3,
0162     },
0163     { },
0164 };
0165 MODULE_DEVICE_TABLE(platform, da9052_wled_ids);
0166
0167 static struct platform_driver da9052_wled_driver = {
0168     .probe      = da9052_backlight_probe,
0169     .remove     = da9052_backlight_remove,
0170     .id_table   = da9052_wled_ids,
0171     .driver = {
0172         .name   = "da9052-wled",
0173     },
0174 };
0175
0176 module_platform_driver(da9052_wled_driver);
0177
0178 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
0179 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
0180 MODULE_LICENSE("GPL");