1/*
  2 * LEDs driver for PCEngines ALIX.2 and ALIX.3
  3 *
  4 * Copyright (C) 2008 Constantin Baranov <const@mimas.ru>
  5 */
  6
  7#include <linux/err.h>
  8#include <linux/io.h>
  9#include <linux/kernel.h>
 10#include <linux/leds.h>
 11#include <linux/module.h>
 12#include <linux/platform_device.h>
 13#include <linux/string.h>
 14#include <linux/pci.h>
 15
 16static int force = 0;
 17module_param(force, bool, 0444);
 18MODULE_PARM_DESC(force, "Assume system has ALIX.2/ALIX.3 style LEDs");
 19
 20#define MSR_LBAR_GPIO		0x5140000C
 21#define CS5535_GPIO_SIZE	256
 22
 23static u32 gpio_base;
 24
 25static struct pci_device_id divil_pci[] = {
 26	{ PCI_DEVICE(PCI_VENDOR_ID_NS,  PCI_DEVICE_ID_NS_CS5535_ISA) },
 27	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
 28	{ } /* NULL entry */
 29};
 30MODULE_DEVICE_TABLE(pci, divil_pci);
 31
 32struct alix_led {
 33	struct led_classdev cdev;
 34	unsigned short port;
 35	unsigned int on_value;
 36	unsigned int off_value;
 37};
 38
 39static void alix_led_set(struct led_classdev *led_cdev,
 40			 enum led_brightness brightness)
 41{
 42	struct alix_led *led_dev =
 43		container_of(led_cdev, struct alix_led, cdev);
 44
 45	if (brightness)
 46		outl(led_dev->on_value, gpio_base + led_dev->port);
 47	else
 48		outl(led_dev->off_value, gpio_base + led_dev->port);
 49}
 50
 51static struct alix_led alix_leds[] = {
 52	{
 53		.cdev = {
 54			.name = "alix:1",
 55			.brightness_set = alix_led_set,
 56		},
 57		.port = 0x00,
 58		.on_value = 1 << 22,
 59		.off_value = 1 << 6,
 60	},
 61	{
 62		.cdev = {
 63			.name = "alix:2",
 64			.brightness_set = alix_led_set,
 65		},
 66		.port = 0x80,
 67		.on_value = 1 << 25,
 68		.off_value = 1 << 9,
 69	},
 70	{
 71		.cdev = {
 72			.name = "alix:3",
 73			.brightness_set = alix_led_set,
 74		},
 75		.port = 0x80,
 76		.on_value = 1 << 27,
 77		.off_value = 1 << 11,
 78	},
 79};
 80
 81static int __init alix_led_probe(struct platform_device *pdev)
 82{
 83	int i;
 84	int ret;
 85
 86	for (i = 0; i < ARRAY_SIZE(alix_leds); i++) {
 87		alix_leds[i].cdev.flags |= LED_CORE_SUSPENDRESUME;
 88		ret = led_classdev_register(&pdev->dev, &alix_leds[i].cdev);
 89		if (ret < 0)
 90			goto fail;
 91	}
 92	return 0;
 93
 94fail:
 95	while (--i >= 0)
 96		led_classdev_unregister(&alix_leds[i].cdev);
 97	return ret;
 98}
 99
100static int alix_led_remove(struct platform_device *pdev)
101{
102	int i;
103
104	for (i = 0; i < ARRAY_SIZE(alix_leds); i++)
105		led_classdev_unregister(&alix_leds[i].cdev);
106	return 0;
107}
108
109static struct platform_driver alix_led_driver = {
110	.remove = alix_led_remove,
111	.driver = {
112		.name = KBUILD_MODNAME,
113		.owner = THIS_MODULE,
114	},
115};
116
117static int __init alix_present(unsigned long bios_phys,
118				const char *alix_sig,
119				size_t alix_sig_len)
120{
121	const size_t bios_len = 0x00010000;
122	const char *bios_virt;
123	const char *scan_end;
124	const char *p;
125	char name[64];
126
127	if (force) {
128		printk(KERN_NOTICE "%s: forced to skip BIOS test, "
129		       "assume system has ALIX.2 style LEDs\n",
130		       KBUILD_MODNAME);
131		return 1;
132	}
133
134	bios_virt = phys_to_virt(bios_phys);
135	scan_end = bios_virt + bios_len - (alix_sig_len + 2);
136	for (p = bios_virt; p < scan_end; p++) {
137		const char *tail;
138		char *a;
139
140		if (memcmp(p, alix_sig, alix_sig_len) != 0)
141			continue;
142
143		memcpy(name, p, sizeof(name));
144
145		/* remove the first \0 character from string */
146		a = strchr(name, '\0');
147		if (a)
148			*a = ' ';
149
150		/* cut the string at a newline */
151		a = strchr(name, '\r');
152		if (a)
153			*a = '\0';
154
155		tail = p + alix_sig_len;
156		if ((tail[0] == '2' || tail[0] == '3')) {
157			printk(KERN_INFO
158			       "%s: system is recognized as \"%s\"\n",
159			       KBUILD_MODNAME, name);
160			return 1;
161		}
162	}
163
164	return 0;
165}
166
167static struct platform_device *pdev;
168
169static int __init alix_pci_led_init(void)
170{
171	u32 low, hi;
172
173	if (pci_dev_present(divil_pci) == 0) {
174		printk(KERN_WARNING KBUILD_MODNAME": DIVIL not found\n");
175		return -ENODEV;
176	}
177
178	/* Grab the GPIO I/O range */
179	rdmsr(MSR_LBAR_GPIO, low, hi);
180
181	/* Check the mask and whether GPIO is enabled (sanity check) */
182	if (hi != 0x0000f001) {
183		printk(KERN_WARNING KBUILD_MODNAME": GPIO not enabled\n");
184		return -ENODEV;
185	}
186
187	/* Mask off the IO base address */
188	gpio_base = low & 0x0000ff00;
189
190	if (!request_region(gpio_base, CS5535_GPIO_SIZE, KBUILD_MODNAME)) {
191		printk(KERN_ERR KBUILD_MODNAME": can't allocate I/O for GPIO\n");
192		return -ENODEV;
193	}
194
195	/* Set GPIO function to output */
196	outl(1 << 6, gpio_base + 0x04);
197	outl(1 << 9, gpio_base + 0x84);
198	outl(1 << 11, gpio_base + 0x84);
199
200	return 0;
201}
202
203static int __init alix_led_init(void)
204{
205	int ret = -ENODEV;
206	const char tinybios_sig[] = "PC Engines ALIX.";
207	const char coreboot_sig[] = "PC Engines\0ALIX.";
208
209	if (alix_present(0xf0000, tinybios_sig, sizeof(tinybios_sig) - 1) ||
210	    alix_present(0x500, coreboot_sig, sizeof(coreboot_sig) - 1))
211		ret = alix_pci_led_init();
212
213	if (ret < 0)
214		return ret;
215
216	pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
217	if (!IS_ERR(pdev)) {
218		ret = platform_driver_probe(&alix_led_driver, alix_led_probe);
219		if (ret)
220			platform_device_unregister(pdev);
221	} else
222		ret = PTR_ERR(pdev);
223
224	return ret;
225}
226
227static void __exit alix_led_exit(void)
228{
229	platform_device_unregister(pdev);
230	platform_driver_unregister(&alix_led_driver);
231	release_region(gpio_base, CS5535_GPIO_SIZE);
232}
233
234module_init(alix_led_init);
235module_exit(alix_led_exit);
236
237MODULE_AUTHOR("Constantin Baranov <const@mimas.ru>");
238MODULE_DESCRIPTION("PCEngines ALIX.2 and ALIX.3 LED driver");
239MODULE_LICENSE("GPL");