video/backlight/da903x_bl.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Backlight driver for Dialog Semiconductor DA9030/DA9034
0004  *
0005  * Copyright (C) 2008 Compulab, Ltd.
0006  *  Mike Rapoport <mike@compulab.co.il>
0007  *
0008  * Copyright (C) 2006-2008 Marvell International Ltd.
0009  *  Eric Miao <eric.miao@marvell.com>
0010  */
0011
0012 #include <linux/kernel.h>
0013 #include <linux/init.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/fb.h>
0016 #include <linux/backlight.h>
0017 #include <linux/mfd/da903x.h>
0018 #include <linux/slab.h>
0019 #include <linux/module.h>
0020
0021 #define DA9030_WLED_CONTROL 0x25
0022 #define DA9030_WLED_CP_EN   (1 << 6)
0023 #define DA9030_WLED_TRIM(x) ((x) & 0x7)
0024
0025 #define DA9034_WLED_CONTROL1    0x3C
0026 #define DA9034_WLED_CONTROL2    0x3D
0027 #define DA9034_WLED_ISET(x) ((x) & 0x1f)
0028
0029 #define DA9034_WLED_BOOST_EN    (1 << 5)
0030
0031 #define DA9030_MAX_BRIGHTNESS   7
0032 #define DA9034_MAX_BRIGHTNESS   0x7f
0033
0034 struct da903x_backlight_data {
0035     struct device *da903x_dev;
0036     int id;
0037     int current_brightness;
0038 };
0039
0040 static int da903x_backlight_set(struct backlight_device *bl, int brightness)
0041 {
0042     struct da903x_backlight_data *data = bl_get_data(bl);
0043     struct device *dev = data->da903x_dev;
0044     uint8_t val;
0045     int ret = 0;
0046
0047     switch (data->id) {
0048     case DA9034_ID_WLED:
0049         ret = da903x_update(dev, DA9034_WLED_CONTROL1,
0050                 brightness, 0x7f);
0051         if (ret)
0052             return ret;
0053
0054         if (data->current_brightness && brightness == 0)
0055             ret = da903x_clr_bits(dev,
0056                     DA9034_WLED_CONTROL2,
0057                     DA9034_WLED_BOOST_EN);
0058
0059         if (data->current_brightness == 0 && brightness)
0060             ret = da903x_set_bits(dev,
0061                     DA9034_WLED_CONTROL2,
0062                     DA9034_WLED_BOOST_EN);
0063         break;
0064     case DA9030_ID_WLED:
0065         val = DA9030_WLED_TRIM(brightness);
0066         val |= brightness ? DA9030_WLED_CP_EN : 0;
0067         ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
0068         break;
0069     }
0070
0071     if (ret)
0072         return ret;
0073
0074     data->current_brightness = brightness;
0075     return 0;
0076 }
0077
0078 static int da903x_backlight_update_status(struct backlight_device *bl)
0079 {
0080     return da903x_backlight_set(bl, backlight_get_brightness(bl));
0081 }
0082
0083 static int da903x_backlight_get_brightness(struct backlight_device *bl)
0084 {
0085     struct da903x_backlight_data *data = bl_get_data(bl);
0086
0087     return data->current_brightness;
0088 }
0089
0090 static const struct backlight_ops da903x_backlight_ops = {
0091     .options    = BL_CORE_SUSPENDRESUME,
0092     .update_status  = da903x_backlight_update_status,
0093     .get_brightness = da903x_backlight_get_brightness,
0094 };
0095
0096 static int da903x_backlight_probe(struct platform_device *pdev)
0097 {
0098     struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
0099     struct da903x_backlight_data *data;
0100     struct backlight_device *bl;
0101     struct backlight_properties props;
0102     int max_brightness;
0103
0104     data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
0105     if (data == NULL)
0106         return -ENOMEM;
0107
0108     switch (pdev->id) {
0109     case DA9030_ID_WLED:
0110         max_brightness = DA9030_MAX_BRIGHTNESS;
0111         break;
0112     case DA9034_ID_WLED:
0113         max_brightness = DA9034_MAX_BRIGHTNESS;
0114         break;
0115     default:
0116         dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
0117                 pdev->id);
0118         return -EINVAL;
0119     }
0120
0121     data->id = pdev->id;
0122     data->da903x_dev = pdev->dev.parent;
0123     data->current_brightness = 0;
0124
0125     /* adjust the WLED output current */
0126     if (pdata)
0127         da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
0128                 DA9034_WLED_ISET(pdata->output_current));
0129
0130     memset(&props, 0, sizeof(props));
0131     props.type = BACKLIGHT_RAW;
0132     props.max_brightness = max_brightness;
0133     bl = devm_backlight_device_register(&pdev->dev, pdev->name,
0134                     data->da903x_dev, data,
0135                     &da903x_backlight_ops, &props);
0136     if (IS_ERR(bl)) {
0137         dev_err(&pdev->dev, "failed to register backlight\n");
0138         return PTR_ERR(bl);
0139     }
0140
0141     bl->props.brightness = max_brightness;
0142
0143     platform_set_drvdata(pdev, bl);
0144     backlight_update_status(bl);
0145     return 0;
0146 }
0147
0148 static struct platform_driver da903x_backlight_driver = {
0149     .driver     = {
0150         .name   = "da903x-backlight",
0151     },
0152     .probe      = da903x_backlight_probe,
0153 };
0154
0155 module_platform_driver(da903x_backlight_driver);
0156
0157 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
0158 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
0159 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
0160 MODULE_LICENSE("GPL");
0161 MODULE_ALIAS("platform:da903x-backlight");