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

/*
 * Backlight driver for Pandora handheld.
 * Pandora uses TWL4030 PWM0 -> TPS61161 combo for control backlight.
 * Based on pwm_bl.c
 *
 * Copyright 2009,2012 Gražvydas Ignotas <notasas@gmail.com>
 *
 * 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/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/i2c/twl.h>
#include <linux/err.h>

#define TWL_PWM0_ON		0x00
#define TWL_PWM0_OFF		0x01

#define TWL_INTBR_GPBR1		0x0c
#define TWL_INTBR_PMBR1		0x0d

#define TWL_PMBR1_PWM0_MUXMASK	0x0c
#define TWL_PMBR1_PWM0		0x04
#define PWM0_CLK_ENABLE		BIT(0)
#define PWM0_ENABLE		BIT(2)

/* range accepted by hardware */
#define MIN_VALUE 9
#define MAX_VALUE 63
#define MAX_USER_VALUE (MAX_VALUE - MIN_VALUE)

#define PANDORABL_WAS_OFF BL_CORE_DRIVER1

static int pandora_backlight_update_status(struct backlight_device *bl)
{
	int brightness = bl->props.brightness;
	u8 r;

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

	if ((unsigned int)brightness > MAX_USER_VALUE)
		brightness = MAX_USER_VALUE;

	if (brightness == 0) {
		if (bl->props.state & PANDORABL_WAS_OFF)
			goto done;

		/* first disable PWM0 output, then clock */
		twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_GPBR1);
		r &= ~PWM0_ENABLE;
		twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);
		r &= ~PWM0_CLK_ENABLE;
		twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);

		goto done;
	}

	if (bl->props.state & PANDORABL_WAS_OFF) {
		/*
		 * set PWM duty cycle to max. TPS61161 seems to use this
		 * to calibrate it's PWM sensitivity when it starts.
		 */
		twl_i2c_write_u8(TWL_MODULE_PWM, MAX_VALUE, TWL_PWM0_OFF);

		/* first enable clock, then PWM0 out */
		twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_GPBR1);
		r &= ~PWM0_ENABLE;
		r |= PWM0_CLK_ENABLE;
		twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);
		r |= PWM0_ENABLE;
		twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);

		/*
		 * TI made it very easy to enable digital control, so easy that
		 * it often triggers unintentionally and disabes PWM control,
		 * so wait until 1 wire mode detection window ends.
		 */
		usleep_range(2000, 10000);
	}

	twl_i2c_write_u8(TWL_MODULE_PWM, MIN_VALUE + brightness, TWL_PWM0_OFF);

done:
	if (brightness != 0)
		bl->props.state &= ~PANDORABL_WAS_OFF;
	else
		bl->props.state |= PANDORABL_WAS_OFF;

	return 0;
}

static const struct backlight_ops pandora_backlight_ops = {
	.options	= BL_CORE_SUSPENDRESUME,
	.update_status	= pandora_backlight_update_status,
};

static int pandora_backlight_probe(struct platform_device *pdev)
{
	struct backlight_properties props;
	struct backlight_device *bl;
	u8 r;

	memset(&props, 0, sizeof(props));
	props.max_brightness = MAX_USER_VALUE;
	props.type = BACKLIGHT_RAW;
	bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev,
					NULL, &pandora_backlight_ops, &props);
	if (IS_ERR(bl)) {
		dev_err(&pdev->dev, "failed to register backlight\n");
		return PTR_ERR(bl);
	}

	platform_set_drvdata(pdev, bl);

	/* 64 cycle period, ON position 0 */
	twl_i2c_write_u8(TWL_MODULE_PWM, 0x80, TWL_PWM0_ON);

	bl->props.state |= PANDORABL_WAS_OFF;
	bl->props.brightness = MAX_USER_VALUE;
	backlight_update_status(bl);

	/* enable PWM function in pin mux */
	twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_PMBR1);
	r &= ~TWL_PMBR1_PWM0_MUXMASK;
	r |= TWL_PMBR1_PWM0;
	twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_PMBR1);

	return 0;
}

static struct platform_driver pandora_backlight_driver = {
	.driver		= {
		.name	= "pandora-backlight",
	},
	.probe		= pandora_backlight_probe,
};

module_platform_driver(pandora_backlight_driver);

MODULE_AUTHOR("Gražvydas Ignotas <notasas@gmail.com>");
MODULE_DESCRIPTION("Pandora Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pandora-backlight");
Commit	Line	Data
35c1682c GI	1	/*
	2	* Backlight driver for Pandora handheld.
	3	* Pandora uses TWL4030 PWM0 -> TPS61161 combo for control backlight.
	4	* Based on pwm_bl.c
	5	*
	6	* Copyright 2009,2012 Gražvydas Ignotas <notasas@gmail.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/kernel.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/delay.h>
	17	#include <linux/fb.h>
	18	#include <linux/backlight.h>
	19	#include <linux/i2c/twl.h>
	20	#include <linux/err.h>
	21
	22	#define TWL_PWM0_ON 0x00
	23	#define TWL_PWM0_OFF 0x01
	24
	25	#define TWL_INTBR_GPBR1 0x0c
	26	#define TWL_INTBR_PMBR1 0x0d
	27
	28	#define TWL_PMBR1_PWM0_MUXMASK 0x0c
	29	#define TWL_PMBR1_PWM0 0x04
	30	#define PWM0_CLK_ENABLE BIT(0)
	31	#define PWM0_ENABLE BIT(2)
	32
	33	/* range accepted by hardware */
	34	#define MIN_VALUE 9
	35	#define MAX_VALUE 63
	36	#define MAX_USER_VALUE (MAX_VALUE - MIN_VALUE)
	37
	38	#define PANDORABL_WAS_OFF BL_CORE_DRIVER1
	39
	40	static int pandora_backlight_update_status(struct backlight_device *bl)
	41	{
	42	int brightness = bl->props.brightness;
	43	u8 r;
	44
	45	if (bl->props.power != FB_BLANK_UNBLANK)
	46	brightness = 0;
	47	if (bl->props.state & BL_CORE_FBBLANK)
	48	brightness = 0;
	49	if (bl->props.state & BL_CORE_SUSPENDED)
	50	brightness = 0;
	51
	52	if ((unsigned int)brightness > MAX_USER_VALUE)
	53	brightness = MAX_USER_VALUE;
	54
	55	if (brightness == 0) {
	56	if (bl->props.state & PANDORABL_WAS_OFF)
	57	goto done;
	58
	59	/* first disable PWM0 output, then clock */
	60	twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_GPBR1);
	61	r &= ~PWM0_ENABLE;
	62	twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);
	63	r &= ~PWM0_CLK_ENABLE;
	64	twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);
65
66	goto done;
67	}
68
69	if (bl->props.state & PANDORABL_WAS_OFF) {
70	/*
71	* set PWM duty cycle to max. TPS61161 seems to use this
72	* to calibrate it's PWM sensitivity when it starts.
73	*/
b444df2f	74	twl_i2c_write_u8(TWL_MODULE_PWM, MAX_VALUE, TWL_PWM0_OFF);
35c1682c GI	75
	76	/* first enable clock, then PWM0 out */
	77	twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_GPBR1);
	78	r &= ~PWM0_ENABLE;
	79	r \|= PWM0_CLK_ENABLE;
	80	twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);
	81	r \|= PWM0_ENABLE;
	82	twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_GPBR1);
	83
	84	/*
	85	* TI made it very easy to enable digital control, so easy that
	86	* it often triggers unintentionally and disabes PWM control,
	87	* so wait until 1 wire mode detection window ends.
	88	*/
	89	usleep_range(2000, 10000);
	90	}
	91
b444df2f	92	twl_i2c_write_u8(TWL_MODULE_PWM, MIN_VALUE + brightness, TWL_PWM0_OFF);
35c1682c GI	93
	94	done:
	95	if (brightness != 0)
	96	bl->props.state &= ~PANDORABL_WAS_OFF;
	97	else
	98	bl->props.state \|= PANDORABL_WAS_OFF;
	99
	100	return 0;
	101	}
	102
35c1682c GI	103	static const struct backlight_ops pandora_backlight_ops = {
	104	.options = BL_CORE_SUSPENDRESUME,
	105	.update_status = pandora_backlight_update_status,
35c1682c GI	106	};
	107
	108	static int pandora_backlight_probe(struct platform_device *pdev)
	109	{
	110	struct backlight_properties props;
	111	struct backlight_device *bl;
	112	u8 r;
	113
	114	memset(&props, 0, sizeof(props));
	115	props.max_brightness = MAX_USER_VALUE;
	116	props.type = BACKLIGHT_RAW;
75d4baec JH	117	bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev,
75d4baec JH	118	NULL, &pandora_backlight_ops, &props);
35c1682c GI	119	if (IS_ERR(bl)) {
	120	dev_err(&pdev->dev, "failed to register backlight\n");
	121	return PTR_ERR(bl);
	122	}
	123
	124	platform_set_drvdata(pdev, bl);
	125
	126	/* 64 cycle period, ON position 0 */
b444df2f	127	twl_i2c_write_u8(TWL_MODULE_PWM, 0x80, TWL_PWM0_ON);
35c1682c GI	128
	129	bl->props.state \|= PANDORABL_WAS_OFF;
	130	bl->props.brightness = MAX_USER_VALUE;
	131	backlight_update_status(bl);
	132
	133	/* enable PWM function in pin mux */
	134	twl_i2c_read_u8(TWL4030_MODULE_INTBR, &r, TWL_INTBR_PMBR1);
	135	r &= ~TWL_PMBR1_PWM0_MUXMASK;
	136	r \|= TWL_PMBR1_PWM0;
	137	twl_i2c_write_u8(TWL4030_MODULE_INTBR, r, TWL_INTBR_PMBR1);
	138
	139	return 0;
	140	}
	141
35c1682c GI	142	static struct platform_driver pandora_backlight_driver = {
	143	.driver = {
	144	.name = "pandora-backlight",
35c1682c GI	145	},
35c1682c GI	146	.probe = pandora_backlight_probe,
35c1682c GI	147	};
	148
	149	module_platform_driver(pandora_backlight_driver);
	150
	151	MODULE_AUTHOR("Gražvydas Ignotas <notasas@gmail.com>");
	152	MODULE_DESCRIPTION("Pandora Backlight Driver");
	153	MODULE_LICENSE("GPL");
	154	MODULE_ALIAS("platform:pandora-backlight");