[linux-2.6-block.git] / drivers / video / backlight / as3711_bl.c

/*
 * AS3711 PMIC backlight driver, using DCDC Step Up Converters
 *
 * Copyright (C) 2012 Renesas Electronics Corporation
 * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the version 2 of the GNU General Public License as
 * published by the Free Software Foundation
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/fb.h>
#include <linux/kernel.h>
#include <linux/mfd/as3711.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

enum as3711_bl_type {
	AS3711_BL_SU1,
	AS3711_BL_SU2,
};

struct as3711_bl_data {
	bool powered;
	const char *fb_name;
	struct device *fb_dev;
	enum as3711_bl_type type;
	int brightness;
	struct backlight_device *bl;
};

struct as3711_bl_supply {
	struct as3711_bl_data su1;
	struct as3711_bl_data su2;
	const struct as3711_bl_pdata *pdata;
	struct as3711 *as3711;
};

static struct as3711_bl_supply *to_supply(struct as3711_bl_data *su)
{
	switch (su->type) {
	case AS3711_BL_SU1:
		return container_of(su, struct as3711_bl_supply, su1);
	case AS3711_BL_SU2:
		return container_of(su, struct as3711_bl_supply, su2);
	}
	return NULL;
}

static int as3711_set_brightness_auto_i(struct as3711_bl_data *data,
					unsigned int brightness)
{
	struct as3711_bl_supply *supply = to_supply(data);
	struct as3711 *as3711 = supply->as3711;
	const struct as3711_bl_pdata *pdata = supply->pdata;
	int ret = 0;

	/* Only all equal current values are supported */
	if (pdata->su2_auto_curr1)
		ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
				   brightness);
	if (!ret && pdata->su2_auto_curr2)
		ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
				   brightness);
	if (!ret && pdata->su2_auto_curr3)
		ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
				   brightness);

	return ret;
}

static int as3711_set_brightness_v(struct as3711 *as3711,
				   unsigned int brightness,
				   unsigned int reg)
{
	if (brightness > 31)
		return -EINVAL;

	return regmap_update_bits(as3711->regmap, reg, 0xf0,
				  brightness << 4);
}

static int as3711_bl_su2_reset(struct as3711_bl_supply *supply)
{
	struct as3711 *as3711 = supply->as3711;
	int ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_5,
				     3, supply->pdata->su2_fbprot);
	if (!ret)
		ret = regmap_update_bits(as3711->regmap,
					 AS3711_STEPUP_CONTROL_2, 1, 0);
	if (!ret)
		ret = regmap_update_bits(as3711->regmap,
					 AS3711_STEPUP_CONTROL_2, 1, 1);
	return ret;
}

/*
 * Someone with less fragile or less expensive hardware could try to simplify
 * the brightness adjustment procedure.
 */
static int as3711_bl_update_status(struct backlight_device *bl)
{
	struct as3711_bl_data *data = bl_get_data(bl);
	struct as3711_bl_supply *supply = to_supply(data);
	struct as3711 *as3711 = supply->as3711;
	int brightness = bl->props.brightness;
	int ret = 0;

	dev_dbg(&bl->dev, "%s(): brightness %u, pwr %x, blank %x, state %x\n",
		__func__, bl->props.brightness, bl->props.power,
		bl->props.fb_blank, bl->props.state);

	if (bl->props.power != FB_BLANK_UNBLANK ||
	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
		brightness = 0;

	if (data->type == AS3711_BL_SU1) {
		ret = as3711_set_brightness_v(as3711, brightness,
					      AS3711_STEPUP_CONTROL_1);
	} else {
		const struct as3711_bl_pdata *pdata = supply->pdata;

		switch (pdata->su2_feedback) {
		case AS3711_SU2_VOLTAGE:
			ret = as3711_set_brightness_v(as3711, brightness,
						      AS3711_STEPUP_CONTROL_2);
			break;
		case AS3711_SU2_CURR_AUTO:
			ret = as3711_set_brightness_auto_i(data, brightness / 4);
			if (ret < 0)
				return ret;
			if (brightness) {
				ret = as3711_bl_su2_reset(supply);
				if (ret < 0)
					return ret;
				udelay(500);
				ret = as3711_set_brightness_auto_i(data, brightness);
			} else {
				ret = regmap_update_bits(as3711->regmap,
						AS3711_STEPUP_CONTROL_2, 1, 0);
			}
			break;
		/* Manual one current feedback pin below */
		case AS3711_SU2_CURR1:
			ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
					   brightness);
			break;
		case AS3711_SU2_CURR2:
			ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
					   brightness);
			break;
		case AS3711_SU2_CURR3:
			ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
					   brightness);
			break;
		default:
			ret = -EINVAL;
		}
	}
	if (!ret)
		data->brightness = brightness;

	return ret;
}

static int as3711_bl_get_brightness(struct backlight_device *bl)
{
	struct as3711_bl_data *data = bl_get_data(bl);

	return data->brightness;
}

static const struct backlight_ops as3711_bl_ops = {
	.update_status	= as3711_bl_update_status,
	.get_brightness	= as3711_bl_get_brightness,
};

static int as3711_bl_init_su2(struct as3711_bl_supply *supply)
{
	struct as3711 *as3711 = supply->as3711;
	const struct as3711_bl_pdata *pdata = supply->pdata;
	u8 ctl = 0;
	int ret;

	dev_dbg(as3711->dev, "%s(): use %u\n", __func__, pdata->su2_feedback);

	/* Turn SU2 off */
	ret = regmap_write(as3711->regmap, AS3711_STEPUP_CONTROL_2, 0);
	if (ret < 0)
		return ret;

	switch (pdata->su2_feedback) {
	case AS3711_SU2_VOLTAGE:
		ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 0);
		break;
	case AS3711_SU2_CURR1:
		ctl = 1;
		ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 1);
		break;
	case AS3711_SU2_CURR2:
		ctl = 4;
		ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 2);
		break;
	case AS3711_SU2_CURR3:
		ctl = 0x10;
		ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 3);
		break;
	case AS3711_SU2_CURR_AUTO:
		if (pdata->su2_auto_curr1)
			ctl = 2;
		if (pdata->su2_auto_curr2)
			ctl |= 8;
		if (pdata->su2_auto_curr3)
			ctl |= 0x20;
		ret = 0;
		break;
	default:
		return -EINVAL;
	}

	if (!ret)
		ret = regmap_write(as3711->regmap, AS3711_CURR_CONTROL, ctl);

	return ret;
}

static int as3711_bl_register(struct platform_device *pdev,
			      unsigned int max_brightness, struct as3711_bl_data *su)
{
	struct backlight_properties props = {.type = BACKLIGHT_RAW,};
	struct backlight_device *bl;

	/* max tuning I = 31uA for voltage- and 38250uA for current-feedback */
	props.max_brightness = max_brightness;

	bl = devm_backlight_device_register(&pdev->dev,
				       su->type == AS3711_BL_SU1 ?
				       "as3711-su1" : "as3711-su2",
				       &pdev->dev, su,
				       &as3711_bl_ops, &props);
	if (IS_ERR(bl)) {
		dev_err(&pdev->dev, "failed to register backlight\n");
		return PTR_ERR(bl);
	}

	bl->props.brightness = props.max_brightness;

	backlight_update_status(bl);

	su->bl = bl;

	return 0;
}

static int as3711_backlight_parse_dt(struct device *dev)
{
	struct as3711_bl_pdata *pdata = dev_get_platdata(dev);
	struct device_node *bl =
		of_find_node_by_name(dev->parent->of_node, "backlight"), *fb;
	int ret;

	if (!bl) {
		dev_dbg(dev, "backlight node not found\n");
		return -ENODEV;
	}

	fb = of_parse_phandle(bl, "su1-dev", 0);
	if (fb) {
		pdata->su1_fb = fb->full_name;

		ret = of_property_read_u32(bl, "su1-max-uA", &pdata->su1_max_uA);
		if (pdata->su1_max_uA <= 0)
			ret = -EINVAL;
		if (ret < 0)
			return ret;
	}

	fb = of_parse_phandle(bl, "su2-dev", 0);
	if (fb) {
		int count = 0;

		pdata->su2_fb = fb->full_name;

		ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA);
		if (pdata->su2_max_uA <= 0)
			ret = -EINVAL;
		if (ret < 0)
			return ret;

		if (of_find_property(bl, "su2-feedback-voltage", NULL)) {
			pdata->su2_feedback = AS3711_SU2_VOLTAGE;
			count++;
		}
		if (of_find_property(bl, "su2-feedback-curr1", NULL)) {
			pdata->su2_feedback = AS3711_SU2_CURR1;
			count++;
		}
		if (of_find_property(bl, "su2-feedback-curr2", NULL)) {
			pdata->su2_feedback = AS3711_SU2_CURR2;
			count++;
		}
		if (of_find_property(bl, "su2-feedback-curr3", NULL)) {
			pdata->su2_feedback = AS3711_SU2_CURR3;
			count++;
		}
		if (of_find_property(bl, "su2-feedback-curr-auto", NULL)) {
			pdata->su2_feedback = AS3711_SU2_CURR_AUTO;
			count++;
		}
		if (count != 1)
			return -EINVAL;

		count = 0;
		if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) {
			pdata->su2_fbprot = AS3711_SU2_LX_SD4;
			count++;
		}
		if (of_find_property(bl, "su2-fbprot-gpio2", NULL)) {
			pdata->su2_fbprot = AS3711_SU2_GPIO2;
			count++;
		}
		if (of_find_property(bl, "su2-fbprot-gpio3", NULL)) {
			pdata->su2_fbprot = AS3711_SU2_GPIO3;
			count++;
		}
		if (of_find_property(bl, "su2-fbprot-gpio4", NULL)) {
			pdata->su2_fbprot = AS3711_SU2_GPIO4;
			count++;
		}
		if (count != 1)
			return -EINVAL;

		count = 0;
		if (of_find_property(bl, "su2-auto-curr1", NULL)) {
			pdata->su2_auto_curr1 = true;
			count++;
		}
		if (of_find_property(bl, "su2-auto-curr2", NULL)) {
			pdata->su2_auto_curr2 = true;
			count++;
		}
		if (of_find_property(bl, "su2-auto-curr3", NULL)) {
			pdata->su2_auto_curr3 = true;
			count++;
		}

		/*
		 * At least one su2-auto-curr* must be specified iff
		 * AS3711_SU2_CURR_AUTO is used
		 */
		if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO))
			return -EINVAL;
	}

	return 0;
}

static int as3711_backlight_probe(struct platform_device *pdev)
{
	struct as3711_bl_pdata *pdata = dev_get_platdata(&pdev->dev);
	struct as3711 *as3711 = dev_get_drvdata(pdev->dev.parent);
	struct as3711_bl_supply *supply;
	struct as3711_bl_data *su;
	unsigned int max_brightness;
	int ret;

	if (!pdata) {
		dev_err(&pdev->dev, "No platform data, exiting...\n");
		return -ENODEV;
	}

	if (pdev->dev.parent->of_node) {
		ret = as3711_backlight_parse_dt(&pdev->dev);
		if (ret < 0) {
			dev_err(&pdev->dev, "DT parsing failed: %d\n", ret);
			return ret;
		}
	}

	if (!pdata->su1_fb && !pdata->su2_fb) {
		dev_err(&pdev->dev, "No framebuffer specified\n");
		return -EINVAL;
	}

	/*
	 * Due to possible hardware damage I chose to block all modes,
	 * unsupported on my hardware. Anyone, wishing to use any of those modes
	 * will have to first review the code, then activate and test it.
	 */
	if (pdata->su1_fb ||
	    pdata->su2_fbprot != AS3711_SU2_GPIO4 ||
	    pdata->su2_feedback != AS3711_SU2_CURR_AUTO) {
		dev_warn(&pdev->dev,
			 "Attention! An untested mode has been chosen!\n"
			 "Please, review the code, enable, test, and report success:-)\n");
		return -EINVAL;
	}

	supply = devm_kzalloc(&pdev->dev, sizeof(*supply), GFP_KERNEL);
	if (!supply)
		return -ENOMEM;

	supply->as3711 = as3711;
	supply->pdata = pdata;

	if (pdata->su1_fb) {
		su = &supply->su1;
		su->fb_name = pdata->su1_fb;
		su->type = AS3711_BL_SU1;

		max_brightness = min(pdata->su1_max_uA, 31);
		ret = as3711_bl_register(pdev, max_brightness, su);
		if (ret < 0)
			return ret;
	}

	if (pdata->su2_fb) {
		su = &supply->su2;
		su->fb_name = pdata->su2_fb;
		su->type = AS3711_BL_SU2;

		switch (pdata->su2_fbprot) {
		case AS3711_SU2_GPIO2:
		case AS3711_SU2_GPIO3:
		case AS3711_SU2_GPIO4:
		case AS3711_SU2_LX_SD4:
			break;
		default:
			return -EINVAL;
		}

		switch (pdata->su2_feedback) {
		case AS3711_SU2_VOLTAGE:
			max_brightness = min(pdata->su2_max_uA, 31);
			break;
		case AS3711_SU2_CURR1:
		case AS3711_SU2_CURR2:
		case AS3711_SU2_CURR3:
		case AS3711_SU2_CURR_AUTO:
			max_brightness = min(pdata->su2_max_uA / 150, 255);
			break;
		default:
			return -EINVAL;
		}

		ret = as3711_bl_init_su2(supply);
		if (ret < 0)
			return ret;

		ret = as3711_bl_register(pdev, max_brightness, su);
		if (ret < 0)
			return ret;
	}

	platform_set_drvdata(pdev, supply);

	return 0;
}

static struct platform_driver as3711_backlight_driver = {
	.driver		= {
		.name	= "as3711-backlight",
	},
	.probe		= as3711_backlight_probe,
};

module_platform_driver(as3711_backlight_driver);

MODULE_DESCRIPTION("Backlight Driver for AS3711 PMICs");
MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:as3711-backlight");
Commit	Line	Data
de474b5b GL	1	/*
	2	* AS3711 PMIC backlight driver, using DCDC Step Up Converters
	3	*
	4	* Copyright (C) 2012 Renesas Electronics Corporation
	5	* Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the version 2 of the GNU General Public License as
	9	* published by the Free Software Foundation
	10	*/
	11
	12	#include <linux/backlight.h>
	13	#include <linux/delay.h>
	14	#include <linux/device.h>
	15	#include <linux/err.h>
	16	#include <linux/fb.h>
	17	#include <linux/kernel.h>
	18	#include <linux/mfd/as3711.h>
	19	#include <linux/module.h>
	20	#include <linux/platform_device.h>
	21	#include <linux/regmap.h>
	22	#include <linux/slab.h>
	23
	24	enum as3711_bl_type {
	25	AS3711_BL_SU1,
	26	AS3711_BL_SU2,
	27	};
	28
	29	struct as3711_bl_data {
	30	bool powered;
	31	const char *fb_name;
	32	struct device *fb_dev;
	33	enum as3711_bl_type type;
	34	int brightness;
	35	struct backlight_device *bl;
	36	};
	37
	38	struct as3711_bl_supply {
	39	struct as3711_bl_data su1;
	40	struct as3711_bl_data su2;
	41	const struct as3711_bl_pdata *pdata;
	42	struct as3711 *as3711;
	43	};
	44
	45	static struct as3711_bl_supply to_supply(struct as3711_bl_data su)
	46	{
	47	switch (su->type) {
	48	case AS3711_BL_SU1:
	49	return container_of(su, struct as3711_bl_supply, su1);
	50	case AS3711_BL_SU2:
	51	return container_of(su, struct as3711_bl_supply, su2);
	52	}
	53	return NULL;
	54	}
	55
	56	static int as3711_set_brightness_auto_i(struct as3711_bl_data *data,
	57	unsigned int brightness)
	58	{
	59	struct as3711_bl_supply *supply = to_supply(data);
	60	struct as3711 *as3711 = supply->as3711;
	61	const struct as3711_bl_pdata *pdata = supply->pdata;
	62	int ret = 0;
	63
	64	/* Only all equal current values are supported */
65	if (pdata->su2_auto_curr1)
66	ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
67	brightness);
68	if (!ret && pdata->su2_auto_curr2)
69	ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
70	brightness);
71	if (!ret && pdata->su2_auto_curr3)
72	ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
73	brightness);
74
75	return ret;
76	}
77
78	static int as3711_set_brightness_v(struct as3711 *as3711,
79	unsigned int brightness,
80	unsigned int reg)
81	{
82	if (brightness > 31)
83	return -EINVAL;
84
85	return regmap_update_bits(as3711->regmap, reg, 0xf0,
86	brightness << 4);
87	}
88
89	static int as3711_bl_su2_reset(struct as3711_bl_supply *supply)
90	{
91	struct as3711 *as3711 = supply->as3711;
92	int ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_5,
93	3, supply->pdata->su2_fbprot);
94	if (!ret)
95	ret = regmap_update_bits(as3711->regmap,
96	AS3711_STEPUP_CONTROL_2, 1, 0);
97	if (!ret)
98	ret = regmap_update_bits(as3711->regmap,
99	AS3711_STEPUP_CONTROL_2, 1, 1);
100	return ret;
101	}
102
103	/*
104	* Someone with less fragile or less expensive hardware could try to simplify
105	* the brightness adjustment procedure.
106	*/
107	static int as3711_bl_update_status(struct backlight_device *bl)
108	{
109	struct as3711_bl_data *data = bl_get_data(bl);
110	struct as3711_bl_supply *supply = to_supply(data);
111	struct as3711 *as3711 = supply->as3711;
112	int brightness = bl->props.brightness;
113	int ret = 0;
114
115	dev_dbg(&bl->dev, "%s(): brightness %u, pwr %x, blank %x, state %x\n",
116	__func__, bl->props.brightness, bl->props.power,
117	bl->props.fb_blank, bl->props.state);
118
119	if (bl->props.power != FB_BLANK_UNBLANK \|\|
120	bl->props.fb_blank != FB_BLANK_UNBLANK \|\|
121	bl->props.state & (BL_CORE_SUSPENDED \| BL_CORE_FBBLANK))
122	brightness = 0;
123
124	if (data->type == AS3711_BL_SU1) {
125	ret = as3711_set_brightness_v(as3711, brightness,
126	AS3711_STEPUP_CONTROL_1);
127	} else {
128	const struct as3711_bl_pdata *pdata = supply->pdata;
129
130	switch (pdata->su2_feedback) {
131	case AS3711_SU2_VOLTAGE:
132	ret = as3711_set_brightness_v(as3711, brightness,
133	AS3711_STEPUP_CONTROL_2);
134	break;
135	case AS3711_SU2_CURR_AUTO:
136	ret = as3711_set_brightness_auto_i(data, brightness / 4);
137	if (ret < 0)
138	return ret;
139	if (brightness) {
140	ret = as3711_bl_su2_reset(supply);
141	if (ret < 0)
142	return ret;
143	udelay(500);
144	ret = as3711_set_brightness_auto_i(data, brightness);
145	} else {
146	ret = regmap_update_bits(as3711->regmap,
147	AS3711_STEPUP_CONTROL_2, 1, 0);
148	}
149	break;
150	/* Manual one current feedback pin below */
151	case AS3711_SU2_CURR1:
152	ret = regmap_write(as3711->regmap, AS3711_CURR1_VALUE,
153	brightness);
154	break;
155	case AS3711_SU2_CURR2:
156	ret = regmap_write(as3711->regmap, AS3711_CURR2_VALUE,
157	brightness);
158	break;
159	case AS3711_SU2_CURR3:
160	ret = regmap_write(as3711->regmap, AS3711_CURR3_VALUE,
161	brightness);
162	break;
163	default:
164	ret = -EINVAL;
165	}
166	}
167	if (!ret)
168	data->brightness = brightness;
169
170	return ret;
171	}
172
173	static int as3711_bl_get_brightness(struct backlight_device *bl)
174	{
175	struct as3711_bl_data *data = bl_get_data(bl);
176
177	return data->brightness;
178	}
179
180	static const struct backlight_ops as3711_bl_ops = {
181	.update_status = as3711_bl_update_status,
182	.get_brightness = as3711_bl_get_brightness,
183	};
184
185	static int as3711_bl_init_su2(struct as3711_bl_supply *supply)
186	{
187	struct as3711 *as3711 = supply->as3711;
188	const struct as3711_bl_pdata *pdata = supply->pdata;
189	u8 ctl = 0;
190	int ret;
191
192	dev_dbg(as3711->dev, "%s(): use %u\n", __func__, pdata->su2_feedback);
193
194	/* Turn SU2 off */
195	ret = regmap_write(as3711->regmap, AS3711_STEPUP_CONTROL_2, 0);
196	if (ret < 0)
197	return ret;
198
199	switch (pdata->su2_feedback) {
200	case AS3711_SU2_VOLTAGE:
201	ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 0);
202	break;
203	case AS3711_SU2_CURR1:
204	ctl = 1;
205	ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 1);
206	break;
207	case AS3711_SU2_CURR2:
208	ctl = 4;
209	ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 2);
210	break;
211	case AS3711_SU2_CURR3:
212	ctl = 0x10;
213	ret = regmap_update_bits(as3711->regmap, AS3711_STEPUP_CONTROL_4, 3, 3);
214	break;
215	case AS3711_SU2_CURR_AUTO:
216	if (pdata->su2_auto_curr1)
217	ctl = 2;
218	if (pdata->su2_auto_curr2)
219	ctl \|= 8;
220	if (pdata->su2_auto_curr3)
221	ctl \|= 0x20;
222	ret = 0;
223	break;
224	default:
225	return -EINVAL;
226	}
227
228	if (!ret)
229	ret = regmap_write(as3711->regmap, AS3711_CURR_CONTROL, ctl);
230
231	return ret;
232	}
233
234	static int as3711_bl_register(struct platform_device *pdev,
235	unsigned int max_brightness, struct as3711_bl_data *su)
236	{
237	struct backlight_properties props = {.type = BACKLIGHT_RAW,};
238	struct backlight_device *bl;
239
240	/* max tuning I = 31uA for voltage- and 38250uA for current-feedback */
241	props.max_brightness = max_brightness;
242
83dedc05 JH	243	bl = devm_backlight_device_register(&pdev->dev,
83dedc05 JH	244	su->type == AS3711_BL_SU1 ?
de474b5b GL	245	"as3711-su1" : "as3711-su2",
	246	&pdev->dev, su,
	247	&as3711_bl_ops, &props);
	248	if (IS_ERR(bl)) {
	249	dev_err(&pdev->dev, "failed to register backlight\n");
	250	return PTR_ERR(bl);
	251	}
	252
	253	bl->props.brightness = props.max_brightness;
	254
	255	backlight_update_status(bl);
	256
	257	su->bl = bl;
	258
	259	return 0;
	260	}
	261
59eb2b5e GL	262	static int as3711_backlight_parse_dt(struct device *dev)
	263	{
	264	struct as3711_bl_pdata *pdata = dev_get_platdata(dev);
	265	struct device_node *bl =
	266	of_find_node_by_name(dev->parent->of_node, "backlight"), *fb;
	267	int ret;
	268
	269	if (!bl) {
	270	dev_dbg(dev, "backlight node not found\n");
	271	return -ENODEV;
	272	}
	273
	274	fb = of_parse_phandle(bl, "su1-dev", 0);
	275	if (fb) {
	276	pdata->su1_fb = fb->full_name;
	277
	278	ret = of_property_read_u32(bl, "su1-max-uA", &pdata->su1_max_uA);
	279	if (pdata->su1_max_uA <= 0)
	280	ret = -EINVAL;
	281	if (ret < 0)
	282	return ret;
	283	}
	284
	285	fb = of_parse_phandle(bl, "su2-dev", 0);
	286	if (fb) {
	287	int count = 0;
	288
	289	pdata->su2_fb = fb->full_name;
	290
	291	ret = of_property_read_u32(bl, "su2-max-uA", &pdata->su2_max_uA);
	292	if (pdata->su2_max_uA <= 0)
	293	ret = -EINVAL;
	294	if (ret < 0)
	295	return ret;
	296
	297	if (of_find_property(bl, "su2-feedback-voltage", NULL)) {
	298	pdata->su2_feedback = AS3711_SU2_VOLTAGE;
	299	count++;
	300	}
	301	if (of_find_property(bl, "su2-feedback-curr1", NULL)) {
	302	pdata->su2_feedback = AS3711_SU2_CURR1;
	303	count++;
	304	}
	305	if (of_find_property(bl, "su2-feedback-curr2", NULL)) {
	306	pdata->su2_feedback = AS3711_SU2_CURR2;
	307	count++;
	308	}
	309	if (of_find_property(bl, "su2-feedback-curr3", NULL)) {
	310	pdata->su2_feedback = AS3711_SU2_CURR3;
	311	count++;
	312	}
	313	if (of_find_property(bl, "su2-feedback-curr-auto", NULL)) {
	314	pdata->su2_feedback = AS3711_SU2_CURR_AUTO;
	315	count++;
	316	}
	317	if (count != 1)
	318	return -EINVAL;
	319
	320	count = 0;
	321	if (of_find_property(bl, "su2-fbprot-lx-sd4", NULL)) {
	322	pdata->su2_fbprot = AS3711_SU2_LX_SD4;
	323	count++;
	324	}
	325	if (of_find_property(bl, "su2-fbprot-gpio2", NULL)) {
326	pdata->su2_fbprot = AS3711_SU2_GPIO2;
327	count++;
328	}
329	if (of_find_property(bl, "su2-fbprot-gpio3", NULL)) {
330	pdata->su2_fbprot = AS3711_SU2_GPIO3;
331	count++;
332	}
333	if (of_find_property(bl, "su2-fbprot-gpio4", NULL)) {
334	pdata->su2_fbprot = AS3711_SU2_GPIO4;
335	count++;
336	}
337	if (count != 1)
338	return -EINVAL;
339
340	count = 0;
341	if (of_find_property(bl, "su2-auto-curr1", NULL)) {
342	pdata->su2_auto_curr1 = true;
343	count++;
344	}
345	if (of_find_property(bl, "su2-auto-curr2", NULL)) {
346	pdata->su2_auto_curr2 = true;
347	count++;
348	}
349	if (of_find_property(bl, "su2-auto-curr3", NULL)) {
350	pdata->su2_auto_curr3 = true;
351	count++;
352	}
353
354	/*
355	* At least one su2-auto-curr* must be specified iff
356	* AS3711_SU2_CURR_AUTO is used
357	*/
358	if (!count ^ (pdata->su2_feedback != AS3711_SU2_CURR_AUTO))
359	return -EINVAL;
360	}
361
362	return 0;
363	}
364
de474b5b GL	365	static int as3711_backlight_probe(struct platform_device *pdev)
	366	{
	367	struct as3711_bl_pdata *pdata = dev_get_platdata(&pdev->dev);
	368	struct as3711 *as3711 = dev_get_drvdata(pdev->dev.parent);
	369	struct as3711_bl_supply *supply;
	370	struct as3711_bl_data *su;
	371	unsigned int max_brightness;
	372	int ret;
	373
59eb2b5e	374	if (!pdata) {
de474b5b GL	375	dev_err(&pdev->dev, "No platform data, exiting...\n");
	376	return -ENODEV;
	377	}
	378
59eb2b5e GL	379	if (pdev->dev.parent->of_node) {
	380	ret = as3711_backlight_parse_dt(&pdev->dev);
	381	if (ret < 0) {
	382	dev_err(&pdev->dev, "DT parsing failed: %d\n", ret);
	383	return ret;
	384	}
	385	}
	386
	387	if (!pdata->su1_fb && !pdata->su2_fb) {
	388	dev_err(&pdev->dev, "No framebuffer specified\n");
	389	return -EINVAL;
	390	}
	391
de474b5b GL	392	/*
	393	* Due to possible hardware damage I chose to block all modes,
	394	* unsupported on my hardware. Anyone, wishing to use any of those modes
	395	* will have to first review the code, then activate and test it.
	396	*/
	397	if (pdata->su1_fb \|\|
	398	pdata->su2_fbprot != AS3711_SU2_GPIO4 \|\|
	399	pdata->su2_feedback != AS3711_SU2_CURR_AUTO) {
	400	dev_warn(&pdev->dev,
	401	"Attention! An untested mode has been chosen!\n"
	402	"Please, review the code, enable, test, and report success:-)\n");
	403	return -EINVAL;
	404	}
	405
	406	supply = devm_kzalloc(&pdev->dev, sizeof(*supply), GFP_KERNEL);
	407	if (!supply)
	408	return -ENOMEM;
	409
	410	supply->as3711 = as3711;
	411	supply->pdata = pdata;
	412
	413	if (pdata->su1_fb) {
	414	su = &supply->su1;
	415	su->fb_name = pdata->su1_fb;
	416	su->type = AS3711_BL_SU1;
	417
	418	max_brightness = min(pdata->su1_max_uA, 31);
	419	ret = as3711_bl_register(pdev, max_brightness, su);
	420	if (ret < 0)
	421	return ret;
	422	}
	423
	424	if (pdata->su2_fb) {
	425	su = &supply->su2;
	426	su->fb_name = pdata->su2_fb;
	427	su->type = AS3711_BL_SU2;
	428
	429	switch (pdata->su2_fbprot) {
	430	case AS3711_SU2_GPIO2:
	431	case AS3711_SU2_GPIO3:
	432	case AS3711_SU2_GPIO4:
	433	case AS3711_SU2_LX_SD4:
	434	break;
	435	default:
83dedc05	436	return -EINVAL;
de474b5b GL	437	}
	438
	439	switch (pdata->su2_feedback) {
	440	case AS3711_SU2_VOLTAGE:
	441	max_brightness = min(pdata->su2_max_uA, 31);
	442	break;
	443	case AS3711_SU2_CURR1:
	444	case AS3711_SU2_CURR2:
	445	case AS3711_SU2_CURR3:
	446	case AS3711_SU2_CURR_AUTO:
	447	max_brightness = min(pdata->su2_max_uA / 150, 255);
	448	break;
	449	default:
83dedc05	450	return -EINVAL;
de474b5b GL	451	}
	452
	453	ret = as3711_bl_init_su2(supply);
	454	if (ret < 0)
	455	return ret;
	456
	457	ret = as3711_bl_register(pdev, max_brightness, su);
	458	if (ret < 0)
83dedc05	459	return ret;
de474b5b GL	460	}
	461
	462	platform_set_drvdata(pdev, supply);
	463
de474b5b GL	464	return 0;
	465	}
	466
	467	static struct platform_driver as3711_backlight_driver = {
	468	.driver = {
	469	.name = "as3711-backlight",
de474b5b GL	470	},
de474b5b GL	471	.probe = as3711_backlight_probe,
de474b5b GL	472	};
	473
	474	module_platform_driver(as3711_backlight_driver);
	475
	476	MODULE_DESCRIPTION("Backlight Driver for AS3711 PMICs");
	477	MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de");
	478	MODULE_LICENSE("GPL");
	479	MODULE_ALIAS("platform:as3711-backlight");