[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / video / backlight / wm831x_bl.c

/*
 * Backlight driver for Wolfson Microelectronics WM831x PMICs
 *
 * Copyright 2009 Wolfson Microelectonics plc
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/slab.h>

#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/regulator.h>

struct wm831x_backlight_data {
	struct wm831x *wm831x;
	int isink_reg;
	int current_brightness;
};

static int wm831x_backlight_set(struct backlight_device *bl, int brightness)
{
	struct wm831x_backlight_data *data = bl_get_data(bl);
	struct wm831x *wm831x = data->wm831x;
	int power_up = !data->current_brightness && brightness;
	int power_down = data->current_brightness && !brightness;
	int ret;

	if (power_up) {
		/* Enable the ISINK */
		ret = wm831x_set_bits(wm831x, data->isink_reg,
				      WM831X_CS1_ENA, WM831X_CS1_ENA);
		if (ret < 0)
			goto err;

		/* Enable the DC-DC */
		ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
				      WM831X_DC4_ENA, WM831X_DC4_ENA);
		if (ret < 0)
			goto err;
	}

	if (power_down) {
		/* DCDC first */
		ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
				      WM831X_DC4_ENA, 0);
		if (ret < 0)
			goto err;

		/* ISINK */
		ret = wm831x_set_bits(wm831x, data->isink_reg,
				      WM831X_CS1_DRIVE | WM831X_CS1_ENA, 0);
		if (ret < 0)
			goto err;
	}

	/* Set the new brightness */
	ret = wm831x_set_bits(wm831x, data->isink_reg,
			      WM831X_CS1_ISEL_MASK, brightness);
	if (ret < 0)
		goto err;

	if (power_up) {
		/* Drive current through the ISINK */
		ret = wm831x_set_bits(wm831x, data->isink_reg,
				      WM831X_CS1_DRIVE, WM831X_CS1_DRIVE);
		if (ret < 0)
			return ret;
	}

	data->current_brightness = brightness;

	return 0;

err:
	/* If we were in the middle of a power transition always shut down
	 * for safety.
	 */
	if (power_up || power_down) {
		wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
		wm831x_set_bits(wm831x, data->isink_reg, WM831X_CS1_ENA, 0);
	}

	return ret;
}

static int wm831x_backlight_update_status(struct backlight_device *bl)
{
	int brightness = bl->props.brightness;

	if (bl->props.power != FB_BLANK_UNBLANK)
		brightness = 0;

	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
		brightness = 0;

	if (bl->props.state & BL_CORE_SUSPENDED)
		brightness = 0;

	return wm831x_backlight_set(bl, brightness);
}

static int wm831x_backlight_get_brightness(struct backlight_device *bl)
{
	struct wm831x_backlight_data *data = bl_get_data(bl);
	return data->current_brightness;
}

static const struct backlight_ops wm831x_backlight_ops = {
	.options = BL_CORE_SUSPENDRESUME,
	.update_status	= wm831x_backlight_update_status,
	.get_brightness	= wm831x_backlight_get_brightness,
};

static int wm831x_backlight_probe(struct platform_device *pdev)
{
	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	struct wm831x_pdata *wm831x_pdata;
	struct wm831x_backlight_pdata *pdata;
	struct wm831x_backlight_data *data;
	struct backlight_device *bl;
	struct backlight_properties props;
	int ret, i, max_isel, isink_reg, dcdc_cfg;

	/* We need platform data */
	if (pdev->dev.parent->platform_data) {
		wm831x_pdata = pdev->dev.parent->platform_data;
		pdata = wm831x_pdata->backlight;
	} else {
		pdata = NULL;
	}

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

	/* Figure out the maximum current we can use */
	for (i = 0; i < WM831X_ISINK_MAX_ISEL; i++) {
		if (wm831x_isinkv_values[i] > pdata->max_uA)
			break;
	}

	if (i == 0) {
		dev_err(&pdev->dev, "Invalid max_uA: %duA\n", pdata->max_uA);
		return -EINVAL;
	}
	max_isel = i - 1;

	if (pdata->max_uA != wm831x_isinkv_values[max_isel])
		dev_warn(&pdev->dev,
			 "Maximum current is %duA not %duA as requested\n",
			 wm831x_isinkv_values[max_isel], pdata->max_uA);

	switch (pdata->isink) {
	case 1:
		isink_reg = WM831X_CURRENT_SINK_1;
		dcdc_cfg = 0;
		break;
	case 2:
		isink_reg = WM831X_CURRENT_SINK_2;
		dcdc_cfg = WM831X_DC4_FBSRC;
		break;
	default:
		dev_err(&pdev->dev, "Invalid ISINK %d\n", pdata->isink);
		return -EINVAL;
	}

	/* Configure the ISINK to use for feedback */
	ret = wm831x_reg_unlock(wm831x);
	if (ret < 0)
		return ret;

	ret = wm831x_set_bits(wm831x, WM831X_DC4_CONTROL, WM831X_DC4_FBSRC,
			      dcdc_cfg);

	wm831x_reg_lock(wm831x);
	if (ret < 0)
		return ret;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (data == NULL)
		return -ENOMEM;

	data->wm831x = wm831x;
	data->current_brightness = 0;
	data->isink_reg = isink_reg;

	props.type = BACKLIGHT_RAW;
	props.max_brightness = max_isel;
	bl = backlight_device_register("wm831x", &pdev->dev, data,
				       &wm831x_backlight_ops, &props);
	if (IS_ERR(bl)) {
		dev_err(&pdev->dev, "failed to register backlight\n");
		kfree(data);
		return PTR_ERR(bl);
	}

	bl->props.brightness = max_isel;

	platform_set_drvdata(pdev, bl);

	/* Disable the DCDC if it was started so we can bootstrap */
	wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);


	backlight_update_status(bl);

	return 0;
}

static int wm831x_backlight_remove(struct platform_device *pdev)
{
	struct backlight_device *bl = platform_get_drvdata(pdev);
	struct wm831x_backlight_data *data = bl_get_data(bl);

	backlight_device_unregister(bl);
	kfree(data);
	return 0;
}

static struct platform_driver wm831x_backlight_driver = {
	.driver		= {
		.name	= "wm831x-backlight",
		.owner	= THIS_MODULE,
	},
	.probe		= wm831x_backlight_probe,
	.remove		= wm831x_backlight_remove,
};

static int __init wm831x_backlight_init(void)
{
	return platform_driver_register(&wm831x_backlight_driver);
}
module_init(wm831x_backlight_init);

static void __exit wm831x_backlight_exit(void)
{
	platform_driver_unregister(&wm831x_backlight_driver);
}
module_exit(wm831x_backlight_exit);

MODULE_DESCRIPTION("Backlight Driver for WM831x PMICs");
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-backlight");
Commit	Line	Data
a4f3d55c MB	1	/*
	2	* Backlight driver for Wolfson Microelectronics WM831x PMICs
	3	*
	4	* Copyright 2009 Wolfson Microelectonics plc
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/init.h>
	13	#include <linux/platform_device.h>
	14	#include <linux/fb.h>
	15	#include <linux/backlight.h>
5a0e3ad6	16	#include <linux/slab.h>
a4f3d55c MB	17
	18	#include <linux/mfd/wm831x/core.h>
	19	#include <linux/mfd/wm831x/pdata.h>
	20	#include <linux/mfd/wm831x/regulator.h>
	21
	22	struct wm831x_backlight_data {
	23	struct wm831x *wm831x;
	24	int isink_reg;
	25	int current_brightness;
	26	};
	27
	28	static int wm831x_backlight_set(struct backlight_device *bl, int brightness)
	29	{
	30	struct wm831x_backlight_data *data = bl_get_data(bl);
	31	struct wm831x *wm831x = data->wm831x;
	32	int power_up = !data->current_brightness && brightness;
	33	int power_down = data->current_brightness && !brightness;
	34	int ret;
	35
	36	if (power_up) {
	37	/* Enable the ISINK */
	38	ret = wm831x_set_bits(wm831x, data->isink_reg,
	39	WM831X_CS1_ENA, WM831X_CS1_ENA);
	40	if (ret < 0)
	41	goto err;
	42
	43	/* Enable the DC-DC */
	44	ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
	45	WM831X_DC4_ENA, WM831X_DC4_ENA);
	46	if (ret < 0)
	47	goto err;
	48	}
	49
	50	if (power_down) {
	51	/* DCDC first */
	52	ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
	53	WM831X_DC4_ENA, 0);
	54	if (ret < 0)
	55	goto err;
	56
	57	/* ISINK */
	58	ret = wm831x_set_bits(wm831x, data->isink_reg,
	59	WM831X_CS1_DRIVE \| WM831X_CS1_ENA, 0);
	60	if (ret < 0)
	61	goto err;
	62	}
	63
	64	/* Set the new brightness */
	65	ret = wm831x_set_bits(wm831x, data->isink_reg,
	66	WM831X_CS1_ISEL_MASK, brightness);
	67	if (ret < 0)
	68	goto err;
	69
	70	if (power_up) {
	71	/* Drive current through the ISINK */
	72	ret = wm831x_set_bits(wm831x, data->isink_reg,
	73	WM831X_CS1_DRIVE, WM831X_CS1_DRIVE);
	74	if (ret < 0)
	75	return ret;
	76	}
	77
	78	data->current_brightness = brightness;
	79
	80	return 0;
81
82	err:
83	/* If we were in the middle of a power transition always shut down
84	* for safety.
85	*/
86	if (power_up \|\| power_down) {
87	wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
88	wm831x_set_bits(wm831x, data->isink_reg, WM831X_CS1_ENA, 0);
89	}
90
91	return ret;
92	}
93
94	static int wm831x_backlight_update_status(struct backlight_device *bl)
95	{
96	int brightness = bl->props.brightness;
97
98	if (bl->props.power != FB_BLANK_UNBLANK)
99	brightness = 0;
100
101	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
102	brightness = 0;
103
104	if (bl->props.state & BL_CORE_SUSPENDED)
105	brightness = 0;
106
107	return wm831x_backlight_set(bl, brightness);
108	}
109
110	static int wm831x_backlight_get_brightness(struct backlight_device *bl)
111	{
112	struct wm831x_backlight_data *data = bl_get_data(bl);
113	return data->current_brightness;
114	}
115
9905a43b	116	static const struct backlight_ops wm831x_backlight_ops = {
a4f3d55c MB	117	.options = BL_CORE_SUSPENDRESUME,
	118	.update_status = wm831x_backlight_update_status,
	119	.get_brightness = wm831x_backlight_get_brightness,
	120	};
	121
	122	static int wm831x_backlight_probe(struct platform_device *pdev)
	123	{
	124	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	125	struct wm831x_pdata *wm831x_pdata;
	126	struct wm831x_backlight_pdata *pdata;
	127	struct wm831x_backlight_data *data;
	128	struct backlight_device *bl;
a19a6ee6	129	struct backlight_properties props;
a4f3d55c MB	130	int ret, i, max_isel, isink_reg, dcdc_cfg;
	131
	132	/* We need platform data */
	133	if (pdev->dev.parent->platform_data) {
	134	wm831x_pdata = pdev->dev.parent->platform_data;
	135	pdata = wm831x_pdata->backlight;
	136	} else {
	137	pdata = NULL;
	138	}
	139
	140	if (!pdata) {
	141	dev_err(&pdev->dev, "No platform data supplied\n");
	142	return -EINVAL;
	143	}
	144
	145	/* Figure out the maximum current we can use */
	146	for (i = 0; i < WM831X_ISINK_MAX_ISEL; i++) {
	147	if (wm831x_isinkv_values[i] > pdata->max_uA)
	148	break;
	149	}
	150
	151	if (i == 0) {
	152	dev_err(&pdev->dev, "Invalid max_uA: %duA\n", pdata->max_uA);
	153	return -EINVAL;
	154	}
	155	max_isel = i - 1;
	156
	157	if (pdata->max_uA != wm831x_isinkv_values[max_isel])
	158	dev_warn(&pdev->dev,
	159	"Maximum current is %duA not %duA as requested\n",
	160	wm831x_isinkv_values[max_isel], pdata->max_uA);
	161
	162	switch (pdata->isink) {
	163	case 1:
	164	isink_reg = WM831X_CURRENT_SINK_1;
	165	dcdc_cfg = 0;
	166	break;
	167	case 2:
	168	isink_reg = WM831X_CURRENT_SINK_2;
	169	dcdc_cfg = WM831X_DC4_FBSRC;
	170	break;
	171	default:
	172	dev_err(&pdev->dev, "Invalid ISINK %d\n", pdata->isink);
	173	return -EINVAL;
	174	}
	175
	176	/* Configure the ISINK to use for feedback */
	177	ret = wm831x_reg_unlock(wm831x);
	178	if (ret < 0)
	179	return ret;
	180
	181	ret = wm831x_set_bits(wm831x, WM831X_DC4_CONTROL, WM831X_DC4_FBSRC,
	182	dcdc_cfg);
	183
	184	wm831x_reg_lock(wm831x);
	185	if (ret < 0)
	186	return ret;
	187
	188	data = kzalloc(sizeof(*data), GFP_KERNEL);
	189	if (data == NULL)
	190	return -ENOMEM;
	191
	192	data->wm831x = wm831x;
	193	data->current_brightness = 0;
194	data->isink_reg = isink_reg;
195
bb7ca747	196	props.type = BACKLIGHT_RAW;
a19a6ee6 MG	197	props.max_brightness = max_isel;
	198	bl = backlight_device_register("wm831x", &pdev->dev, data,
	199	&wm831x_backlight_ops, &props);
a4f3d55c MB	200	if (IS_ERR(bl)) {
	201	dev_err(&pdev->dev, "failed to register backlight\n");
	202	kfree(data);
	203	return PTR_ERR(bl);
	204	}
	205
a4f3d55c MB	206	bl->props.brightness = max_isel;
	207
	208	platform_set_drvdata(pdev, bl);
	209
	210	/* Disable the DCDC if it was started so we can bootstrap */
	211	wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
	212
	213
	214	backlight_update_status(bl);
	215
	216	return 0;
	217	}
	218
	219	static int wm831x_backlight_remove(struct platform_device *pdev)
	220	{
	221	struct backlight_device *bl = platform_get_drvdata(pdev);
	222	struct wm831x_backlight_data *data = bl_get_data(bl);
	223
	224	backlight_device_unregister(bl);
	225	kfree(data);
	226	return 0;
	227	}
	228
	229	static struct platform_driver wm831x_backlight_driver = {
	230	.driver = {
	231	.name = "wm831x-backlight",
	232	.owner = THIS_MODULE,
	233	},
	234	.probe = wm831x_backlight_probe,
	235	.remove = wm831x_backlight_remove,
	236	};
	237
	238	static int __init wm831x_backlight_init(void)
	239	{
	240	return platform_driver_register(&wm831x_backlight_driver);
	241	}
	242	module_init(wm831x_backlight_init);
	243
	244	static void __exit wm831x_backlight_exit(void)
	245	{
	246	platform_driver_unregister(&wm831x_backlight_driver);
	247	}
	248	module_exit(wm831x_backlight_exit);
	249
	250	MODULE_DESCRIPTION("Backlight Driver for WM831x PMICs");
	251	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com");
	252	MODULE_LICENSE("GPL");
	253	MODULE_ALIAS("platform:wm831x-backlight");