da903x_bl.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Backlight driver for Dialog Semiconductor DA9030/DA9034
  4 *
  5 * Copyright (C) 2008 Compulab, Ltd.
  6 *	Mike Rapoport <mike@compulab.co.il>
  7 *
  8 * Copyright (C) 2006-2008 Marvell International Ltd.
  9 *	Eric Miao <eric.miao@marvell.com>
 10 */
 11
 12#include <linux/kernel.h>
 13#include <linux/init.h>
 14#include <linux/platform_device.h>
 15#include <linux/backlight.h>
 16#include <linux/mfd/da903x.h>
 17#include <linux/slab.h>
 18#include <linux/module.h>
 19
 20#define DA9030_WLED_CONTROL	0x25
 21#define DA9030_WLED_CP_EN	(1 << 6)
 22#define DA9030_WLED_TRIM(x)	((x) & 0x7)
 23
 24#define DA9034_WLED_CONTROL1	0x3C
 25#define DA9034_WLED_CONTROL2	0x3D
 26#define DA9034_WLED_ISET(x)	((x) & 0x1f)
 27
 28#define DA9034_WLED_BOOST_EN	(1 << 5)
 29
 30#define DA9030_MAX_BRIGHTNESS	7
 31#define DA9034_MAX_BRIGHTNESS	0x7f
 32
 33struct da903x_backlight_data {
 34	struct device *da903x_dev;
 35	int id;
 36	int current_brightness;
 37};
 38
 39static int da903x_backlight_set(struct backlight_device *bl, int brightness)
 40{
 41	struct da903x_backlight_data *data = bl_get_data(bl);
 42	struct device *dev = data->da903x_dev;
 43	uint8_t val;
 44	int ret = 0;
 45
 46	switch (data->id) {
 47	case DA9034_ID_WLED:
 48		ret = da903x_update(dev, DA9034_WLED_CONTROL1,
 49				brightness, 0x7f);
 50		if (ret)
 51			return ret;
 52
 53		if (data->current_brightness && brightness == 0)
 54			ret = da903x_clr_bits(dev,
 55					DA9034_WLED_CONTROL2,
 56					DA9034_WLED_BOOST_EN);
 57
 58		if (data->current_brightness == 0 && brightness)
 59			ret = da903x_set_bits(dev,
 60					DA9034_WLED_CONTROL2,
 61					DA9034_WLED_BOOST_EN);
 62		break;
 63	case DA9030_ID_WLED:
 64		val = DA9030_WLED_TRIM(brightness);
 65		val |= brightness ? DA9030_WLED_CP_EN : 0;
 66		ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
 67		break;
 68	}
 69
 70	if (ret)
 71		return ret;
 72
 73	data->current_brightness = brightness;
 74	return 0;
 75}
 76
 77static int da903x_backlight_update_status(struct backlight_device *bl)
 78{
 79	return da903x_backlight_set(bl, backlight_get_brightness(bl));
 80}
 81
 82static int da903x_backlight_get_brightness(struct backlight_device *bl)
 83{
 84	struct da903x_backlight_data *data = bl_get_data(bl);
 85
 86	return data->current_brightness;
 87}
 88
 89static const struct backlight_ops da903x_backlight_ops = {
 90	.options	= BL_CORE_SUSPENDRESUME,
 91	.update_status	= da903x_backlight_update_status,
 92	.get_brightness	= da903x_backlight_get_brightness,
 93};
 94
 95static int da903x_backlight_probe(struct platform_device *pdev)
 96{
 97	struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev);
 98	struct da903x_backlight_data *data;
 99	struct backlight_device *bl;
100	struct backlight_properties props;
101	int max_brightness;
102
103	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
104	if (data == NULL)
105		return -ENOMEM;
106
107	switch (pdev->id) {
108	case DA9030_ID_WLED:
109		max_brightness = DA9030_MAX_BRIGHTNESS;
110		break;
111	case DA9034_ID_WLED:
112		max_brightness = DA9034_MAX_BRIGHTNESS;
113		break;
114	default:
115		dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
116				pdev->id);
117		return -EINVAL;
118	}
119
120	data->id = pdev->id;
121	data->da903x_dev = pdev->dev.parent;
122	data->current_brightness = 0;
123
124	/* adjust the WLED output current */
125	if (pdata)
126		da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
127				DA9034_WLED_ISET(pdata->output_current));
128
129	memset(&props, 0, sizeof(props));
130	props.type = BACKLIGHT_RAW;
131	props.max_brightness = max_brightness;
132	bl = devm_backlight_device_register(&pdev->dev, pdev->name,
133					data->da903x_dev, data,
134					&da903x_backlight_ops, &props);
135	if (IS_ERR(bl)) {
136		dev_err(&pdev->dev, "failed to register backlight\n");
137		return PTR_ERR(bl);
138	}
139
140	bl->props.brightness = max_brightness;
141
142	platform_set_drvdata(pdev, bl);
143	backlight_update_status(bl);
144	return 0;
145}
146
147static struct platform_driver da903x_backlight_driver = {
148	.driver		= {
149		.name	= "da903x-backlight",
150	},
151	.probe		= da903x_backlight_probe,
152};
153
154module_platform_driver(da903x_backlight_driver);
155
156MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
157MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
158MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
159MODULE_LICENSE("GPL");
160MODULE_ALIAS("platform:da903x-backlight");