[mirror_ubuntu-artful-kernel.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/module.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,
};

module_platform_driver(wm831x_backlight_driver);

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>
355b200b	14	#include <linux/module.h>
a4f3d55c MB	15	#include <linux/fb.h>
a4f3d55c MB	16	#include <linux/backlight.h>
5a0e3ad6	17	#include <linux/slab.h>
a4f3d55c MB	18
	19	#include <linux/mfd/wm831x/core.h>
	20	#include <linux/mfd/wm831x/pdata.h>
	21	#include <linux/mfd/wm831x/regulator.h>
	22
	23	struct wm831x_backlight_data {
	24	struct wm831x *wm831x;
	25	int isink_reg;
	26	int current_brightness;
	27	};
	28
	29	static int wm831x_backlight_set(struct backlight_device *bl, int brightness)
	30	{
	31	struct wm831x_backlight_data *data = bl_get_data(bl);
	32	struct wm831x *wm831x = data->wm831x;
	33	int power_up = !data->current_brightness && brightness;
	34	int power_down = data->current_brightness && !brightness;
	35	int ret;
	36
	37	if (power_up) {
	38	/* Enable the ISINK */
	39	ret = wm831x_set_bits(wm831x, data->isink_reg,
	40	WM831X_CS1_ENA, WM831X_CS1_ENA);
	41	if (ret < 0)
	42	goto err;
	43
	44	/* Enable the DC-DC */
	45	ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
	46	WM831X_DC4_ENA, WM831X_DC4_ENA);
	47	if (ret < 0)
	48	goto err;
	49	}
	50
	51	if (power_down) {
	52	/* DCDC first */
	53	ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
	54	WM831X_DC4_ENA, 0);
	55	if (ret < 0)
	56	goto err;
	57
	58	/* ISINK */
	59	ret = wm831x_set_bits(wm831x, data->isink_reg,
	60	WM831X_CS1_DRIVE \| WM831X_CS1_ENA, 0);
	61	if (ret < 0)
	62	goto err;
	63	}
	64
	65	/* Set the new brightness */
	66	ret = wm831x_set_bits(wm831x, data->isink_reg,
	67	WM831X_CS1_ISEL_MASK, brightness);
	68	if (ret < 0)
	69	goto err;
	70
	71	if (power_up) {
	72	/* Drive current through the ISINK */
	73	ret = wm831x_set_bits(wm831x, data->isink_reg,
	74	WM831X_CS1_DRIVE, WM831X_CS1_DRIVE);
	75	if (ret < 0)
	76	return ret;
	77	}
	78
	79	data->current_brightness = brightness;
	80
	81	return 0;
82
83	err:
84	/* If we were in the middle of a power transition always shut down
85	* for safety.
86	*/
87	if (power_up \|\| power_down) {
88	wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
89	wm831x_set_bits(wm831x, data->isink_reg, WM831X_CS1_ENA, 0);
90	}
91
92	return ret;
93	}
94
95	static int wm831x_backlight_update_status(struct backlight_device *bl)
96	{
97	int brightness = bl->props.brightness;
98
99	if (bl->props.power != FB_BLANK_UNBLANK)
100	brightness = 0;
101
102	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
103	brightness = 0;
104
105	if (bl->props.state & BL_CORE_SUSPENDED)
106	brightness = 0;
107
108	return wm831x_backlight_set(bl, brightness);
109	}
110
111	static int wm831x_backlight_get_brightness(struct backlight_device *bl)
112	{
113	struct wm831x_backlight_data *data = bl_get_data(bl);
114	return data->current_brightness;
115	}
116
9905a43b	117	static const struct backlight_ops wm831x_backlight_ops = {
a4f3d55c MB	118	.options = BL_CORE_SUSPENDRESUME,
	119	.update_status = wm831x_backlight_update_status,
	120	.get_brightness = wm831x_backlight_get_brightness,
	121	};
	122
	123	static int wm831x_backlight_probe(struct platform_device *pdev)
	124	{
	125	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	126	struct wm831x_pdata *wm831x_pdata;
	127	struct wm831x_backlight_pdata *pdata;
	128	struct wm831x_backlight_data *data;
	129	struct backlight_device *bl;
a19a6ee6	130	struct backlight_properties props;
a4f3d55c MB	131	int ret, i, max_isel, isink_reg, dcdc_cfg;
	132
	133	/* We need platform data */
	134	if (pdev->dev.parent->platform_data) {
	135	wm831x_pdata = pdev->dev.parent->platform_data;
	136	pdata = wm831x_pdata->backlight;
	137	} else {
	138	pdata = NULL;
	139	}
	140
	141	if (!pdata) {
	142	dev_err(&pdev->dev, "No platform data supplied\n");
	143	return -EINVAL;
	144	}
	145
	146	/* Figure out the maximum current we can use */
	147	for (i = 0; i < WM831X_ISINK_MAX_ISEL; i++) {
	148	if (wm831x_isinkv_values[i] > pdata->max_uA)
	149	break;
	150	}
	151
	152	if (i == 0) {
	153	dev_err(&pdev->dev, "Invalid max_uA: %duA\n", pdata->max_uA);
	154	return -EINVAL;
	155	}
	156	max_isel = i - 1;
	157
	158	if (pdata->max_uA != wm831x_isinkv_values[max_isel])
	159	dev_warn(&pdev->dev,
	160	"Maximum current is %duA not %duA as requested\n",
	161	wm831x_isinkv_values[max_isel], pdata->max_uA);
	162
	163	switch (pdata->isink) {
	164	case 1:
	165	isink_reg = WM831X_CURRENT_SINK_1;
	166	dcdc_cfg = 0;
	167	break;
	168	case 2:
	169	isink_reg = WM831X_CURRENT_SINK_2;
	170	dcdc_cfg = WM831X_DC4_FBSRC;
	171	break;
	172	default:
	173	dev_err(&pdev->dev, "Invalid ISINK %d\n", pdata->isink);
	174	return -EINVAL;
	175	}
	176
	177	/* Configure the ISINK to use for feedback */
	178	ret = wm831x_reg_unlock(wm831x);
	179	if (ret < 0)
	180	return ret;
	181
	182	ret = wm831x_set_bits(wm831x, WM831X_DC4_CONTROL, WM831X_DC4_FBSRC,
	183	dcdc_cfg);
	184
	185	wm831x_reg_lock(wm831x);
	186	if (ret < 0)
	187	return ret;
	188
	189	data = kzalloc(sizeof(*data), GFP_KERNEL);
	190	if (data == NULL)
	191	return -ENOMEM;
	192
	193	data->wm831x = wm831x;
	194	data->current_brightness = 0;
195	data->isink_reg = isink_reg;
196
bb7ca747	197	props.type = BACKLIGHT_RAW;
a19a6ee6 MG	198	props.max_brightness = max_isel;
	199	bl = backlight_device_register("wm831x", &pdev->dev, data,
	200	&wm831x_backlight_ops, &props);
a4f3d55c MB	201	if (IS_ERR(bl)) {
	202	dev_err(&pdev->dev, "failed to register backlight\n");
	203	kfree(data);
	204	return PTR_ERR(bl);
	205	}
	206
a4f3d55c MB	207	bl->props.brightness = max_isel;
	208
	209	platform_set_drvdata(pdev, bl);
	210
	211	/* Disable the DCDC if it was started so we can bootstrap */
	212	wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
	213
	214
	215	backlight_update_status(bl);
	216
	217	return 0;
	218	}
	219
	220	static int wm831x_backlight_remove(struct platform_device *pdev)
	221	{
	222	struct backlight_device *bl = platform_get_drvdata(pdev);
	223	struct wm831x_backlight_data *data = bl_get_data(bl);
	224
	225	backlight_device_unregister(bl);
	226	kfree(data);
	227	return 0;
	228	}
	229
	230	static struct platform_driver wm831x_backlight_driver = {
	231	.driver = {
	232	.name = "wm831x-backlight",
	233	.owner = THIS_MODULE,
	234	},
	235	.probe = wm831x_backlight_probe,
	236	.remove = wm831x_backlight_remove,
	237	};
	238
81178e02	239	module_platform_driver(wm831x_backlight_driver);
a4f3d55c MB	240
	241	MODULE_DESCRIPTION("Backlight Driver for WM831x PMICs");
	242	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com");
	243	MODULE_LICENSE("GPL");
	244	MODULE_ALIAS("platform:wm831x-backlight");