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 #include <linux/module.h>
18
19 /*
20 * The HTC ASIC3 LED GPIOs are inputs, not outputs.
21 * Hence we turn the LEDs on/off via the TimeBase register.
22 */
23
24 /*
25 * When TimeBase is 4 the clock resolution is about 32Hz.
26 * This driver supports hardware blinking with an on+off
27 * period from 62ms (2 clocks) to 125s (4000 clocks).
28 */
29 #define MS_TO_CLK(ms) DIV_ROUND_CLOSEST(((ms)*1024), 32000)
30 #define CLK_TO_MS(clk) (((clk)*32000)/1024)
31 #define MAX_CLK 4000 /* Fits into 12-bit Time registers */
32 #define MAX_MS CLK_TO_MS(MAX_CLK)
33
34 static const unsigned int led_n_base[ASIC3_NUM_LEDS] = {
35 [0] = ASIC3_LED_0_Base,
36 [1] = ASIC3_LED_1_Base,
37 [2] = ASIC3_LED_2_Base,
38 };
39
brightness_set(struct led_classdev * cdev,enum led_brightness value)40 static void brightness_set(struct led_classdev *cdev,
41 enum led_brightness value)
42 {
43 struct platform_device *pdev = to_platform_device(cdev->dev->parent);
44 const struct mfd_cell *cell = mfd_get_cell(pdev);
45 struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
46 u32 timebase;
47 unsigned int base;
48
49 timebase = (value == LED_OFF) ? 0 : (LED_EN|0x4);
50
51 base = led_n_base[cell->id];
52 asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), 32);
53 asic3_write_register(asic, (base + ASIC3_LED_DutyTime), 32);
54 asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
55 asic3_write_register(asic, (base + ASIC3_LED_TimeBase), timebase);
56 }
57
blink_set(struct led_classdev * cdev,unsigned long * delay_on,unsigned long * delay_off)58 static int blink_set(struct led_classdev *cdev,
59 unsigned long *delay_on,
60 unsigned long *delay_off)
61 {
62 struct platform_device *pdev = to_platform_device(cdev->dev->parent);
63 const struct mfd_cell *cell = mfd_get_cell(pdev);
64 struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
65 u32 on;
66 u32 off;
67 unsigned int base;
68
69 if (*delay_on > MAX_MS || *delay_off > MAX_MS)
70 return -EINVAL;
71
72 if (*delay_on == 0 && *delay_off == 0) {
73 /* If both are zero then a sensible default should be chosen */
74 on = MS_TO_CLK(500);
75 off = MS_TO_CLK(500);
76 } else {
77 on = MS_TO_CLK(*delay_on);
78 off = MS_TO_CLK(*delay_off);
79 if ((on + off) > MAX_CLK)
80 return -EINVAL;
81 }
82
83 base = led_n_base[cell->id];
84 asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), (on + off));
85 asic3_write_register(asic, (base + ASIC3_LED_DutyTime), on);
86 asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
87 asic3_write_register(asic, (base + ASIC3_LED_TimeBase), (LED_EN|0x4));
88
89 *delay_on = CLK_TO_MS(on);
90 *delay_off = CLK_TO_MS(off);
91
92 return 0;
93 }
94
asic3_led_probe(struct platform_device * pdev)95 static int __devinit asic3_led_probe(struct platform_device *pdev)
96 {
97 struct asic3_led *led = pdev->dev.platform_data;
98 int ret;
99
100 ret = mfd_cell_enable(pdev);
101 if (ret < 0)
102 goto ret0;
103
104 led->cdev = kzalloc(sizeof(struct led_classdev), GFP_KERNEL);
105 if (!led->cdev) {
106 ret = -ENOMEM;
107 goto ret1;
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 ret2;
119
120 return 0;
121
122 ret2:
123 kfree(led->cdev);
124 ret1:
125 (void) mfd_cell_disable(pdev);
126 ret0:
127 return ret;
128 }
129
asic3_led_remove(struct platform_device * pdev)130 static int __devexit asic3_led_remove(struct platform_device *pdev)
131 {
132 struct asic3_led *led = pdev->dev.platform_data;
133
134 led_classdev_unregister(led->cdev);
135
136 kfree(led->cdev);
137
138 return mfd_cell_disable(pdev);
139 }
140
asic3_led_suspend(struct device * dev)141 static int asic3_led_suspend(struct device *dev)
142 {
143 struct platform_device *pdev = to_platform_device(dev);
144 const struct mfd_cell *cell = mfd_get_cell(pdev);
145 int ret;
146
147 ret = 0;
148 if (cell->suspend)
149 ret = (*cell->suspend)(pdev);
150
151 return ret;
152 }
153
asic3_led_resume(struct device * dev)154 static int asic3_led_resume(struct device *dev)
155 {
156 struct platform_device *pdev = to_platform_device(dev);
157 const struct mfd_cell *cell = mfd_get_cell(pdev);
158 int ret;
159
160 ret = 0;
161 if (cell->resume)
162 ret = (*cell->resume)(pdev);
163
164 return ret;
165 }
166
167 static const struct dev_pm_ops asic3_led_pm_ops = {
168 .suspend = asic3_led_suspend,
169 .resume = asic3_led_resume,
170 };
171
172 static struct platform_driver asic3_led_driver = {
173 .probe = asic3_led_probe,
174 .remove = __devexit_p(asic3_led_remove),
175 .driver = {
176 .name = "leds-asic3",
177 .owner = THIS_MODULE,
178 .pm = &asic3_led_pm_ops,
179 },
180 };
181
182 module_platform_driver(asic3_led_driver);
183
184 MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
185 MODULE_DESCRIPTION("HTC ASIC3 LED driver");
186 MODULE_LICENSE("GPL");
187 MODULE_ALIAS("platform:leds-asic3");
188