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
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
brightness_set(struct led_classdev * cdev,enum led_brightness value)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
blink_set(struct led_classdev * cdev,unsigned long * delay_on,unsigned long * delay_off)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
asic3_led_probe(struct platform_device * pdev)94 static 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
122 out:
123 (void) mfd_cell_disable(pdev);
124 return ret;
125 }
126
asic3_led_remove(struct platform_device * pdev)127 static 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
asic3_led_suspend(struct device * dev)137 static 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
asic3_led_resume(struct device * dev)150 static 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
164 static SIMPLE_DEV_PM_OPS(asic3_led_pm_ops, asic3_led_suspend, asic3_led_resume);
165
166 static 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
175 module_platform_driver(asic3_led_driver);
176
177 MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
178 MODULE_DESCRIPTION("HTC ASIC3 LED driver");
179 MODULE_LICENSE("GPL");
180 MODULE_ALIAS("platform:leds-asic3");
181