drivers/leds/leds-alix2.c

   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
  16 static int force = 0;
  17 module_param(force, bool, 0444);
  18 MODULE_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
  23 static u32 gpio_base;
  24
  25 static 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 };
  30 MODULE_DEVICE_TABLE(pci, divil_pci);
  31
  32 struct alix_led {
  33         struct led_classdev cdev;
  34         unsigned short port;
  35         unsigned int on_value;
  36         unsigned int off_value;
  37 };
  38
  39 static 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
  51 static 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
  81 static 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
  94 fail:
  95         while (--i >= 0)
  96                 led_classdev_unregister(&alix_leds[i].cdev);
  97         return ret;
  98 }
  99
 100 static 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
 109 static struct platform_driver alix_led_driver = {
 110         .remove = alix_led_remove,
 111         .driver = {
 112                 .name = KBUILD_MODNAME,
 113                 .owner = THIS_MODULE,
 114         },
 115 };
 116
 117 static 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
 167 static struct platform_device *pdev;
 168
 169 static 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
 203 static 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
 227 static 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
 234 module_init(alix_led_init);
 235 module_exit(alix_led_exit);
 236
 237 MODULE_AUTHOR("Constantin Baranov <const@mimas.ru>");
 238 MODULE_DESCRIPTION("PCEngines ALIX.2 and ALIX.3 LED driver");
 239 MODULE_LICENSE("GPL");