1/*
  2 * drivers/leds/leds-apu.c
  3 * Copyright (C) 2017 Alan Mizrahi, alan at mizrahi dot com dot ve
  4 *
  5 * Redistribution and use in source and binary forms, with or without
  6 * modification, are permitted provided that the following conditions are met:
  7 *
  8 * 1. Redistributions of source code must retain the above copyright
  9 *    notice, this list of conditions and the following disclaimer.
 10 * 2. Redistributions in binary form must reproduce the above copyright
 11 *    notice, this list of conditions and the following disclaimer in the
 12 *    documentation and/or other materials provided with the distribution.
 13 * 3. Neither the names of the copyright holders nor the names of its
 14 *    contributors may be used to endorse or promote products derived from
 15 *    this software without specific prior written permission.
 16 *
 17 * Alternatively, this software may be distributed under the terms of the
 18 * GNU General Public License ("GPL") version 2 as published by the Free
 19 * Software Foundation.
 20 *
 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 31 * POSSIBILITY OF SUCH DAMAGE.
 32 */
 33
 34#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 35
 36#include <linux/dmi.h>
 37#include <linux/err.h>
 38#include <linux/init.h>
 39#include <linux/io.h>
 40#include <linux/kernel.h>
 41#include <linux/leds.h>
 42#include <linux/module.h>
 43#include <linux/platform_device.h>
 44
 45#define APU1_FCH_ACPI_MMIO_BASE 0xFED80000
 46#define APU1_FCH_GPIO_BASE      (APU1_FCH_ACPI_MMIO_BASE + 0x01BD)
 47#define APU1_LEDON              0x08
 48#define APU1_LEDOFF             0xC8
 49#define APU1_NUM_GPIO           3
 50#define APU1_IOSIZE             sizeof(u8)
 51
 52/* LED access parameters */
 53struct apu_param {
 54	void __iomem *addr; /* for ioread/iowrite */
 55};
 56
 57/* LED private data */
 58struct apu_led_priv {
 59	struct led_classdev cdev;
 60	struct apu_param param;
 61};
 62#define cdev_to_priv(c) container_of(c, struct apu_led_priv, cdev)
 63
 64/* LED profile */
 65struct apu_led_profile {
 66	const char *name;
 67	enum led_brightness brightness;
 68	unsigned long offset; /* for devm_ioremap */
 69};
 70
 71struct apu_led_pdata {
 72	struct platform_device *pdev;
 73	struct apu_led_priv *pled;
 74	spinlock_t lock;
 75};
 76
 77static struct apu_led_pdata *apu_led;
 78
 79static const struct apu_led_profile apu1_led_profile[] = {
 80	{ "apu:green:1", LED_ON,  APU1_FCH_GPIO_BASE + 0 * APU1_IOSIZE },
 81	{ "apu:green:2", LED_OFF, APU1_FCH_GPIO_BASE + 1 * APU1_IOSIZE },
 82	{ "apu:green:3", LED_OFF, APU1_FCH_GPIO_BASE + 2 * APU1_IOSIZE },
 83};
 84
 85static const struct dmi_system_id apu_led_dmi_table[] __initconst = {
 86	{
 87		.ident = "apu",
 88		.matches = {
 89			DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"),
 90			DMI_MATCH(DMI_PRODUCT_NAME, "APU")
 91		}
 92	},
 93	{}
 94};
 95MODULE_DEVICE_TABLE(dmi, apu_led_dmi_table);
 96
 97static void apu1_led_brightness_set(struct led_classdev *led, enum led_brightness value)
 98{
 99	struct apu_led_priv *pled = cdev_to_priv(led);
100
101	spin_lock(&apu_led->lock);
102	iowrite8(value ? APU1_LEDON : APU1_LEDOFF, pled->param.addr);
103	spin_unlock(&apu_led->lock);
104}
105
106static int apu_led_config(struct device *dev, struct apu_led_pdata *apuld)
107{
108	int i;
109	int err;
110
111	apu_led->pled = devm_kcalloc(dev,
112		ARRAY_SIZE(apu1_led_profile), sizeof(struct apu_led_priv),
113		GFP_KERNEL);
114
115	if (!apu_led->pled)
116		return -ENOMEM;
117
118	for (i = 0; i < ARRAY_SIZE(apu1_led_profile); i++) {
119		struct apu_led_priv *pled = &apu_led->pled[i];
120		struct led_classdev *led_cdev = &pled->cdev;
121
122		led_cdev->name = apu1_led_profile[i].name;
123		led_cdev->brightness = apu1_led_profile[i].brightness;
124		led_cdev->max_brightness = 1;
125		led_cdev->flags = LED_CORE_SUSPENDRESUME;
126		led_cdev->brightness_set = apu1_led_brightness_set;
127
128		pled->param.addr = devm_ioremap(dev,
129				apu1_led_profile[i].offset, APU1_IOSIZE);
130		if (!pled->param.addr) {
131			err = -ENOMEM;
132			goto error;
133		}
134
135		err = led_classdev_register(dev, led_cdev);
136		if (err)
137			goto error;
138
139		apu1_led_brightness_set(led_cdev, apu1_led_profile[i].brightness);
140	}
141
142	return 0;
143
144error:
145	while (i-- > 0)
146		led_classdev_unregister(&apu_led->pled[i].cdev);
147
148	return err;
149}
150
151static int __init apu_led_probe(struct platform_device *pdev)
152{
153	apu_led = devm_kzalloc(&pdev->dev, sizeof(*apu_led), GFP_KERNEL);
154
155	if (!apu_led)
156		return -ENOMEM;
157
158	apu_led->pdev = pdev;
159
160	spin_lock_init(&apu_led->lock);
161	return apu_led_config(&pdev->dev, apu_led);
162}
163
164static struct platform_driver apu_led_driver = {
165	.driver = {
166		.name = KBUILD_MODNAME,
167	},
168};
169
170static int __init apu_led_init(void)
171{
172	struct platform_device *pdev;
173	int err;
174
175	if (!(dmi_match(DMI_SYS_VENDOR, "PC Engines") &&
176	      dmi_match(DMI_PRODUCT_NAME, "APU"))) {
177		pr_err("No PC Engines APUv1 board detected. For APUv2,3 support, enable CONFIG_PCENGINES_APU2\n");
178		return -ENODEV;
179	}
180
181	pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
182	if (IS_ERR(pdev)) {
183		pr_err("Device allocation failed\n");
184		return PTR_ERR(pdev);
185	}
186
187	err = platform_driver_probe(&apu_led_driver, apu_led_probe);
188	if (err) {
189		pr_err("Probe platform driver failed\n");
190		platform_device_unregister(pdev);
191	}
192
193	return err;
194}
195
196static void __exit apu_led_exit(void)
197{
198	int i;
199
200	for (i = 0; i < ARRAY_SIZE(apu1_led_profile); i++)
201		led_classdev_unregister(&apu_led->pled[i].cdev);
202
203	platform_device_unregister(apu_led->pdev);
204	platform_driver_unregister(&apu_led_driver);
205}
206
207module_init(apu_led_init);
208module_exit(apu_led_exit);
209
210MODULE_AUTHOR("Alan Mizrahi");
211MODULE_DESCRIPTION("PC Engines APU1 front LED driver");
212MODULE_LICENSE("GPL v2");
213MODULE_ALIAS("platform:leds_apu");