blob: 22f847c890c9bfc23fb5a2f5d7b7658d5551773e [file] [log] [blame]
Paul Parsons7d9e7e92011-05-13 18:52:56 +00001/*
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/init.h>
11#include <linux/platform_device.h>
12#include <linux/leds.h>
13#include <linux/slab.h>
14
15#include <linux/mfd/asic3.h>
16#include <linux/mfd/core.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 __devinit asic3_led_probe(struct platform_device *pdev)
95{
96 struct asic3_led *led = pdev->dev.platform_data;
97 int ret;
98
99 ret = mfd_cell_enable(pdev);
100 if (ret < 0)
101 goto ret0;
102
103 led->cdev = kzalloc(sizeof(struct led_classdev), GFP_KERNEL);
104 if (!led->cdev) {
105 ret = -ENOMEM;
106 goto ret1;
107 }
108
109 led->cdev->name = led->name;
110 led->cdev->default_trigger = led->default_trigger;
111 led->cdev->brightness_set = brightness_set;
112 led->cdev->blink_set = blink_set;
113
114 ret = led_classdev_register(&pdev->dev, led->cdev);
115 if (ret < 0)
116 goto ret2;
117
118 return 0;
119
120ret2:
121 kfree(led->cdev);
122ret1:
123 (void) mfd_cell_disable(pdev);
124ret0:
125 return ret;
126}
127
128static int __devexit asic3_led_remove(struct platform_device *pdev)
129{
130 struct asic3_led *led = pdev->dev.platform_data;
131
132 led_classdev_unregister(led->cdev);
133
134 kfree(led->cdev);
135
136 return mfd_cell_disable(pdev);
137}
138
139static struct platform_driver asic3_led_driver = {
140 .probe = asic3_led_probe,
141 .remove = __devexit_p(asic3_led_remove),
142 .driver = {
143 .name = "leds-asic3",
144 .owner = THIS_MODULE,
145 },
146};
147
148MODULE_ALIAS("platform:leds-asic3");
149
150static int __init asic3_led_init(void)
151{
152 return platform_driver_register(&asic3_led_driver);
153}
154
155static void __exit asic3_led_exit(void)
156{
157 platform_driver_unregister(&asic3_led_driver);
158}
159
160module_init(asic3_led_init);
161module_exit(asic3_led_exit);
162
163MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
164MODULE_DESCRIPTION("HTC ASIC3 LED driver");
165MODULE_LICENSE("GPL");