GNU Linux-libre 4.19.264-gnu1
[releases.git] / arch / arm / plat-omap / debug-leds.c
1 /*
2  * linux/arch/arm/plat-omap/debug-leds.c
3  *
4  * Copyright 2011 by Bryan Wu <bryan.wu@canonical.com>
5  * Copyright 2003 by Texas Instruments Incorporated
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/leds.h>
16 #include <linux/io.h>
17 #include <linux/platform_data/gpio-omap.h>
18 #include <linux/slab.h>
19
20 #include <asm/mach-types.h>
21
22 /* Many OMAP development platforms reuse the same "debug board"; these
23  * platforms include H2, H3, H4, and Perseus2.  There are 16 LEDs on the
24  * debug board (all green), accessed through FPGA registers.
25  */
26
27 /* NOTE:  most boards don't have a static mapping for the FPGA ... */
28 struct h2p2_dbg_fpga {
29         /* offset 0x00 */
30         u16             smc91x[8];
31         /* offset 0x10 */
32         u16             fpga_rev;
33         u16             board_rev;
34         u16             gpio_outputs;
35         u16             leds;
36         /* offset 0x18 */
37         u16             misc_inputs;
38         u16             lan_status;
39         u16             lan_reset;
40         u16             reserved0;
41         /* offset 0x20 */
42         u16             ps2_data;
43         u16             ps2_ctrl;
44         /* plus also 4 rs232 ports ... */
45 };
46
47 static struct h2p2_dbg_fpga __iomem *fpga;
48
49 static u16 fpga_led_state;
50
51 struct dbg_led {
52         struct led_classdev     cdev;
53         u16                     mask;
54 };
55
56 static const struct {
57         const char *name;
58         const char *trigger;
59 } dbg_leds[] = {
60         { "dbg:d4", "heartbeat", },
61         { "dbg:d5", "cpu0", },
62         { "dbg:d6", "default-on", },
63         { "dbg:d7", },
64         { "dbg:d8", },
65         { "dbg:d9", },
66         { "dbg:d10", },
67         { "dbg:d11", },
68         { "dbg:d12", },
69         { "dbg:d13", },
70         { "dbg:d14", },
71         { "dbg:d15", },
72         { "dbg:d16", },
73         { "dbg:d17", },
74         { "dbg:d18", },
75         { "dbg:d19", },
76 };
77
78 /*
79  * The triggers lines up below will only be used if the
80  * LED triggers are compiled in.
81  */
82 static void dbg_led_set(struct led_classdev *cdev,
83                               enum led_brightness b)
84 {
85         struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
86         u16 reg;
87
88         reg = readw_relaxed(&fpga->leds);
89         if (b != LED_OFF)
90                 reg |= led->mask;
91         else
92                 reg &= ~led->mask;
93         writew_relaxed(reg, &fpga->leds);
94 }
95
96 static enum led_brightness dbg_led_get(struct led_classdev *cdev)
97 {
98         struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
99         u16 reg;
100
101         reg = readw_relaxed(&fpga->leds);
102         return (reg & led->mask) ? LED_FULL : LED_OFF;
103 }
104
105 static int fpga_probe(struct platform_device *pdev)
106 {
107         struct resource *iomem;
108         int i;
109
110         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
111         if (!iomem)
112                 return -ENODEV;
113
114         fpga = ioremap(iomem->start, resource_size(iomem));
115         writew_relaxed(0xff, &fpga->leds);
116
117         for (i = 0; i < ARRAY_SIZE(dbg_leds); i++) {
118                 struct dbg_led *led;
119
120                 led = kzalloc(sizeof(*led), GFP_KERNEL);
121                 if (!led)
122                         break;
123
124                 led->cdev.name = dbg_leds[i].name;
125                 led->cdev.brightness_set = dbg_led_set;
126                 led->cdev.brightness_get = dbg_led_get;
127                 led->cdev.default_trigger = dbg_leds[i].trigger;
128                 led->mask = BIT(i);
129
130                 if (led_classdev_register(NULL, &led->cdev) < 0) {
131                         kfree(led);
132                         break;
133                 }
134         }
135
136         return 0;
137 }
138
139 static int fpga_suspend_noirq(struct device *dev)
140 {
141         fpga_led_state = readw_relaxed(&fpga->leds);
142         writew_relaxed(0xff, &fpga->leds);
143
144         return 0;
145 }
146
147 static int fpga_resume_noirq(struct device *dev)
148 {
149         writew_relaxed(~fpga_led_state, &fpga->leds);
150         return 0;
151 }
152
153 static const struct dev_pm_ops fpga_dev_pm_ops = {
154         .suspend_noirq = fpga_suspend_noirq,
155         .resume_noirq = fpga_resume_noirq,
156 };
157
158 static struct platform_driver led_driver = {
159         .driver.name    = "omap_dbg_led",
160         .driver.pm      = &fpga_dev_pm_ops,
161         .probe          = fpga_probe,
162 };
163
164 static int __init fpga_init(void)
165 {
166         if (machine_is_omap_h4()
167                         || machine_is_omap_h3()
168                         || machine_is_omap_h2()
169                         || machine_is_omap_perseus2()
170                         )
171                 return platform_driver_register(&led_driver);
172         return 0;
173 }
174 fs_initcall(fpga_init);