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 ... */
28struct 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
47static struct h2p2_dbg_fpga __iomem *fpga;
48
49static u16 fpga_led_state;
50
51struct dbg_led {
52	struct led_classdev	cdev;
53	u16			mask;
54};
55
56static 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 */
82static 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
96static 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
105static 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
139static 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
147static int fpga_resume_noirq(struct device *dev)
148{
149	writew_relaxed(~fpga_led_state, &fpga->leds);
150	return 0;
151}
152
153static const struct dev_pm_ops fpga_dev_pm_ops = {
154	.suspend_noirq = fpga_suspend_noirq,
155	.resume_noirq = fpga_resume_noirq,
156};
157
158static struct platform_driver led_driver = {
159	.driver.name	= "omap_dbg_led",
160	.driver.pm	= &fpga_dev_pm_ops,
161	.probe		= fpga_probe,
162};
163
164static 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}
174fs_initcall(fpga_init);
175