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 ... */
 25struct 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
 44static struct h2p2_dbg_fpga __iomem *fpga;
 45
 46static u16 fpga_led_state;
 47
 48struct dbg_led {
 49	struct led_classdev	cdev;
 50	u16			mask;
 51};
 52
 53static 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 */
 79static 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
 93static 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
102static 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
136static 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
144static int fpga_resume_noirq(struct device *dev)
145{
146	writew_relaxed(~fpga_led_state, &fpga->leds);
147	return 0;
148}
149
150static const struct dev_pm_ops fpga_dev_pm_ops = {
151	.suspend_noirq = fpga_suspend_noirq,
152	.resume_noirq = fpga_resume_noirq,
153};
154
155static struct platform_driver led_driver = {
156	.driver.name	= "omap_dbg_led",
157	.driver.pm	= &fpga_dev_pm_ops,
158	.probe		= fpga_probe,
159};
160
161static 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}
171fs_initcall(fpga_init);