1/*
2 *  Copyright (C) 2011 Paul Parsons <lost.distance@yahoo.com>
3 *
4 *  This program is free software; you can redistribute it and/or modify
5 *  it under the terms of the GNU General Public License version 2 as
6 *  published by the Free Software Foundation.
7 */
8
9#include <linux/kernel.h>
10#include <linux/platform_device.h>
11#include <linux/leds.h>
12#include <linux/slab.h>
13
14#include <linux/mfd/asic3.h>
15#include <linux/mfd/core.h>
16#include <linux/module.h>
17
18/*
19 *	The HTC ASIC3 LED GPIOs are inputs, not outputs.
20 *	Hence we turn the LEDs on/off via the TimeBase register.
21 */
22
23/*
24 *	When TimeBase is 4 the clock resolution is about 32Hz.
25 *	This driver supports hardware blinking with an on+off
26 *	period from 62ms (2 clocks) to 125s (4000 clocks).
27 */
28#define MS_TO_CLK(ms)	DIV_ROUND_CLOSEST(((ms)*1024), 32000)
29#define CLK_TO_MS(clk)	(((clk)*32000)/1024)
30#define MAX_CLK		4000            /* Fits into 12-bit Time registers */
31#define MAX_MS		CLK_TO_MS(MAX_CLK)
32
33static const unsigned int led_n_base[ASIC3_NUM_LEDS] = {
34	[0] = ASIC3_LED_0_Base,
35	[1] = ASIC3_LED_1_Base,
36	[2] = ASIC3_LED_2_Base,
37};
38
39static void brightness_set(struct led_classdev *cdev,
40	enum led_brightness value)
41{
42	struct platform_device *pdev = to_platform_device(cdev->dev->parent);
43	const struct mfd_cell *cell = mfd_get_cell(pdev);
44	struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
45	u32 timebase;
46	unsigned int base;
47
48	timebase = (value == LED_OFF) ? 0 : (LED_EN|0x4);
49
50	base = led_n_base[cell->id];
51	asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), 32);
52	asic3_write_register(asic, (base + ASIC3_LED_DutyTime), 32);
53	asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
54	asic3_write_register(asic, (base + ASIC3_LED_TimeBase), timebase);
55}
56
57static int blink_set(struct led_classdev *cdev,
58	unsigned long *delay_on,
59	unsigned long *delay_off)
60{
61	struct platform_device *pdev = to_platform_device(cdev->dev->parent);
62	const struct mfd_cell *cell = mfd_get_cell(pdev);
63	struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
64	u32 on;
65	u32 off;
66	unsigned int base;
67
68	if (*delay_on > MAX_MS || *delay_off > MAX_MS)
69		return -EINVAL;
70
71	if (*delay_on == 0 && *delay_off == 0) {
72		/* If both are zero then a sensible default should be chosen */
73		on = MS_TO_CLK(500);
74		off = MS_TO_CLK(500);
75	} else {
76		on = MS_TO_CLK(*delay_on);
77		off = MS_TO_CLK(*delay_off);
78		if ((on + off) > MAX_CLK)
79			return -EINVAL;
80	}
81
82	base = led_n_base[cell->id];
83	asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), (on + off));
84	asic3_write_register(asic, (base + ASIC3_LED_DutyTime), on);
85	asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
86	asic3_write_register(asic, (base + ASIC3_LED_TimeBase), (LED_EN|0x4));
87
88	*delay_on = CLK_TO_MS(on);
89	*delay_off = CLK_TO_MS(off);
90
91	return 0;
92}
93
94static int asic3_led_probe(struct platform_device *pdev)
95{
96	struct asic3_led *led = dev_get_platdata(&pdev->dev);
97	int ret;
98
99	ret = mfd_cell_enable(pdev);
100	if (ret < 0)
101		return ret;
102
103	led->cdev = devm_kzalloc(&pdev->dev, sizeof(struct led_classdev),
104				GFP_KERNEL);
105	if (!led->cdev) {
106		ret = -ENOMEM;
107		goto out;
108	}
109
110	led->cdev->name = led->name;
111	led->cdev->flags = LED_CORE_SUSPENDRESUME;
112	led->cdev->brightness_set = brightness_set;
113	led->cdev->blink_set = blink_set;
114	led->cdev->default_trigger = led->default_trigger;
115
116	ret = led_classdev_register(&pdev->dev, led->cdev);
117	if (ret < 0)
118		goto out;
119
120	return 0;
121
122out:
123	(void) mfd_cell_disable(pdev);
124	return ret;
125}
126
127static int asic3_led_remove(struct platform_device *pdev)
128{
129	struct asic3_led *led = dev_get_platdata(&pdev->dev);
130
131	led_classdev_unregister(led->cdev);
132
133	return mfd_cell_disable(pdev);
134}
135
136#ifdef CONFIG_PM_SLEEP
137static int asic3_led_suspend(struct device *dev)
138{
139	struct platform_device *pdev = to_platform_device(dev);
140	const struct mfd_cell *cell = mfd_get_cell(pdev);
141	int ret;
142
143	ret = 0;
144	if (cell->suspend)
145		ret = (*cell->suspend)(pdev);
146
147	return ret;
148}
149
150static int asic3_led_resume(struct device *dev)
151{
152	struct platform_device *pdev = to_platform_device(dev);
153	const struct mfd_cell *cell = mfd_get_cell(pdev);
154	int ret;
155
156	ret = 0;
157	if (cell->resume)
158		ret = (*cell->resume)(pdev);
159
160	return ret;
161}
162#endif
163
164static SIMPLE_DEV_PM_OPS(asic3_led_pm_ops, asic3_led_suspend, asic3_led_resume);
165
166static struct platform_driver asic3_led_driver = {
167	.probe		= asic3_led_probe,
168	.remove		= asic3_led_remove,
169	.driver		= {
170		.name	= "leds-asic3",
171		.pm	= &asic3_led_pm_ops,
172	},
173};
174
175module_platform_driver(asic3_led_driver);
176
177MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
178MODULE_DESCRIPTION("HTC ASIC3 LED driver");
179MODULE_LICENSE("GPL");
180MODULE_ALIAS("platform:leds-asic3");
181