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