1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/plat-omap/debug-leds.c
4 *
5 * Copyright 2011 by Bryan Wu <bryan.wu@canonical.com>
6 * Copyright 2003 by Texas Instruments Incorporated
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/io.h>
14 #include <linux/platform_data/gpio-omap.h>
15 #include <linux/slab.h>
16
17 #include <asm/mach-types.h>
18
19 /* Many OMAP development platforms reuse the same "debug board"; these
20 * platforms include H2, H3, H4, and Perseus2. There are 16 LEDs on the
21 * debug board (all green), accessed through FPGA registers.
22 */
23
24 /* NOTE: most boards don't have a static mapping for the FPGA ... */
25 struct h2p2_dbg_fpga {
26 /* offset 0x00 */
27 u16 smc91x[8];
28 /* offset 0x10 */
29 u16 fpga_rev;
30 u16 board_rev;
31 u16 gpio_outputs;
32 u16 leds;
33 /* offset 0x18 */
34 u16 misc_inputs;
35 u16 lan_status;
36 u16 lan_reset;
37 u16 reserved0;
38 /* offset 0x20 */
39 u16 ps2_data;
40 u16 ps2_ctrl;
41 /* plus also 4 rs232 ports ... */
42 };
43
44 static struct h2p2_dbg_fpga __iomem *fpga;
45
46 static u16 fpga_led_state;
47
48 struct dbg_led {
49 struct led_classdev cdev;
50 u16 mask;
51 };
52
53 static const struct {
54 const char *name;
55 const char *trigger;
56 } dbg_leds[] = {
57 { "dbg:d4", "heartbeat", },
58 { "dbg:d5", "cpu0", },
59 { "dbg:d6", "default-on", },
60 { "dbg:d7", },
61 { "dbg:d8", },
62 { "dbg:d9", },
63 { "dbg:d10", },
64 { "dbg:d11", },
65 { "dbg:d12", },
66 { "dbg:d13", },
67 { "dbg:d14", },
68 { "dbg:d15", },
69 { "dbg:d16", },
70 { "dbg:d17", },
71 { "dbg:d18", },
72 { "dbg:d19", },
73 };
74
75 /*
76 * The triggers lines up below will only be used if the
77 * LED triggers are compiled in.
78 */
dbg_led_set(struct led_classdev * cdev,enum led_brightness b)79 static void dbg_led_set(struct led_classdev *cdev,
80 enum led_brightness b)
81 {
82 struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
83 u16 reg;
84
85 reg = readw_relaxed(&fpga->leds);
86 if (b != LED_OFF)
87 reg |= led->mask;
88 else
89 reg &= ~led->mask;
90 writew_relaxed(reg, &fpga->leds);
91 }
92
dbg_led_get(struct led_classdev * cdev)93 static enum led_brightness dbg_led_get(struct led_classdev *cdev)
94 {
95 struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
96 u16 reg;
97
98 reg = readw_relaxed(&fpga->leds);
99 return (reg & led->mask) ? LED_FULL : LED_OFF;
100 }
101
fpga_probe(struct platform_device * pdev)102 static int fpga_probe(struct platform_device *pdev)
103 {
104 struct resource *iomem;
105 int i;
106
107 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
108 if (!iomem)
109 return -ENODEV;
110
111 fpga = ioremap(iomem->start, resource_size(iomem));
112 writew_relaxed(0xff, &fpga->leds);
113
114 for (i = 0; i < ARRAY_SIZE(dbg_leds); i++) {
115 struct dbg_led *led;
116
117 led = kzalloc(sizeof(*led), GFP_KERNEL);
118 if (!led)
119 break;
120
121 led->cdev.name = dbg_leds[i].name;
122 led->cdev.brightness_set = dbg_led_set;
123 led->cdev.brightness_get = dbg_led_get;
124 led->cdev.default_trigger = dbg_leds[i].trigger;
125 led->mask = BIT(i);
126
127 if (led_classdev_register(NULL, &led->cdev) < 0) {
128 kfree(led);
129 break;
130 }
131 }
132
133 return 0;
134 }
135
fpga_suspend_noirq(struct device * dev)136 static int fpga_suspend_noirq(struct device *dev)
137 {
138 fpga_led_state = readw_relaxed(&fpga->leds);
139 writew_relaxed(0xff, &fpga->leds);
140
141 return 0;
142 }
143
fpga_resume_noirq(struct device * dev)144 static int fpga_resume_noirq(struct device *dev)
145 {
146 writew_relaxed(~fpga_led_state, &fpga->leds);
147 return 0;
148 }
149
150 static const struct dev_pm_ops fpga_dev_pm_ops = {
151 .suspend_noirq = fpga_suspend_noirq,
152 .resume_noirq = fpga_resume_noirq,
153 };
154
155 static struct platform_driver led_driver = {
156 .driver.name = "omap_dbg_led",
157 .driver.pm = &fpga_dev_pm_ops,
158 .probe = fpga_probe,
159 };
160
fpga_init(void)161 static int __init fpga_init(void)
162 {
163 if (machine_is_omap_h4()
164 || machine_is_omap_h3()
165 || machine_is_omap_h2()
166 || machine_is_omap_perseus2()
167 )
168 return platform_driver_register(&led_driver);
169 return 0;
170 }
171 fs_initcall(fpga_init);
172