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7d9e7e9f PP |
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/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 | ||
33 | static 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 | ||
39 | static 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 | ||
57 | static 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 | ||
94 | static 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 | ||
120 | ret2: | |
121 | kfree(led->cdev); | |
122 | ret1: | |
123 | (void) mfd_cell_disable(pdev); | |
124 | ret0: | |
125 | return ret; | |
126 | } | |
127 | ||
128 | static 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 | ||
139 | static 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 | ||
148 | MODULE_ALIAS("platform:leds-asic3"); | |
149 | ||
150 | static int __init asic3_led_init(void) | |
151 | { | |
152 | return platform_driver_register(&asic3_led_driver); | |
153 | } | |
154 | ||
155 | static void __exit asic3_led_exit(void) | |
156 | { | |
157 | platform_driver_unregister(&asic3_led_driver); | |
158 | } | |
159 | ||
160 | module_init(asic3_led_init); | |
161 | module_exit(asic3_led_exit); | |
162 | ||
163 | MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>"); | |
164 | MODULE_DESCRIPTION("HTC ASIC3 LED driver"); | |
165 | MODULE_LICENSE("GPL"); |