drivers/platform/x86/chromeos_laptop.c

   1 /*
   2  *  chromeos_laptop.c - Driver to instantiate Chromebook i2c/smbus devices.
   3  *
   4  *  Author : Benson Leung <bleung@chromium.org>
   5  *
   6  *  Copyright (C) 2012 Google, Inc.
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  */
  23
  24 #include <linux/dmi.h>
  25 #include <linux/i2c.h>
  26 #include <linux/module.h>
  27
  28 #define CYAPA_TP_I2C_ADDR       0x67
  29 #define ISL_ALS_I2C_ADDR        0x44
  30
  31 static struct i2c_client *als;
  32 static struct i2c_client *tp;
  33
  34 const char *i2c_adapter_names[] = {
  35         "SMBus I801 adapter",
  36 };
  37
  38 /* Keep this enum consistent with i2c_adapter_names */
  39 enum i2c_adapter_type {
  40         I2C_ADAPTER_SMBUS = 0,
  41 };
  42
  43 static struct i2c_board_info __initdata cyapa_device = {
  44         I2C_BOARD_INFO("cyapa", CYAPA_TP_I2C_ADDR),
  45         .flags          = I2C_CLIENT_WAKE,
  46 };
  47
  48 static struct i2c_board_info __initdata isl_als_device = {
  49         I2C_BOARD_INFO("isl29018", ISL_ALS_I2C_ADDR),
  50 };
  51
  52 static struct i2c_client __init *__add_probed_i2c_device(
  53                 const char *name,
  54                 int bus,
  55                 struct i2c_board_info *info,
  56                 const unsigned short *addrs)
  57 {
  58         const struct dmi_device *dmi_dev;
  59         const struct dmi_dev_onboard *dev_data;
  60         struct i2c_adapter *adapter;
  61         struct i2c_client *client;
  62
  63         if (bus < 0)
  64                 return NULL;
  65         /*
  66          * If a name is specified, look for irq platform information stashed
  67          * in DMI_DEV_TYPE_DEV_ONBOARD by the Chrome OS custom system firmware.
  68          */
  69         if (name) {
  70                 dmi_dev = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, name, NULL);
  71                 if (!dmi_dev) {
  72                         pr_err("%s failed to dmi find device %s.\n",
  73                                __func__,
  74                                name);
  75                         return NULL;
  76                 }
  77                 dev_data = (struct dmi_dev_onboard *)dmi_dev->device_data;
  78                 if (!dev_data) {
  79                         pr_err("%s failed to get data from dmi for %s.\n",
  80                                __func__, name);
  81                         return NULL;
  82                 }
  83                 info->irq = dev_data->instance;
  84         }
  85
  86         adapter = i2c_get_adapter(bus);
  87         if (!adapter) {
  88                 pr_err("%s failed to get i2c adapter %d.\n", __func__, bus);
  89                 return NULL;
  90         }
  91
  92         /* add the i2c device */
  93         client = i2c_new_probed_device(adapter, info, addrs, NULL);
  94         if (!client)
  95                 pr_err("%s failed to register device %d-%02x\n",
  96                        __func__, bus, info->addr);
  97         else
  98                 pr_debug("%s added i2c device %d-%02x\n",
  99                          __func__, bus, info->addr);
 100
 101         i2c_put_adapter(adapter);
 102         return client;
 103 }
 104
 105 static int __init __find_i2c_adap(struct device *dev, void *data)
 106 {
 107         const char *name = data;
 108         static const char *prefix = "i2c-";
 109         struct i2c_adapter *adapter;
 110         if (strncmp(dev_name(dev), prefix, strlen(prefix)) != 0)
 111                 return 0;
 112         adapter = to_i2c_adapter(dev);
 113         return (strncmp(adapter->name, name, strlen(name)) == 0);
 114 }
 115
 116 static int __init find_i2c_adapter_num(enum i2c_adapter_type type)
 117 {
 118         struct device *dev = NULL;
 119         struct i2c_adapter *adapter;
 120         const char *name = i2c_adapter_names[type];
 121         /* find the adapter by name */
 122         dev = bus_find_device(&i2c_bus_type, NULL, (void *)name,
 123                               __find_i2c_adap);
 124         if (!dev) {
 125                 pr_err("%s: i2c adapter %s not found on system.\n", __func__,
 126                        name);
 127                 return -ENODEV;
 128         }
 129         adapter = to_i2c_adapter(dev);
 130         return adapter->nr;
 131 }
 132
 133 /*
 134  * Probes for a device at a single address, the one provided by
 135  * info->addr.
 136  * Returns NULL if no device found.
 137  */
 138 static struct i2c_client __init *add_smbus_device(const char *name,
 139                                                   struct i2c_board_info *info)
 140 {
 141         const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
 142         return __add_probed_i2c_device(name,
 143                                        find_i2c_adapter_num(I2C_ADAPTER_SMBUS),
 144                                        info,
 145                                        addr_list);
 146 }
 147
 148 static int __init setup_cyapa_smbus_tp(const struct dmi_system_id *id)
 149 {
 150         /* add cyapa touchpad on smbus */
 151         tp = add_smbus_device("trackpad", &cyapa_device);
 152         return 0;
 153 }
 154
 155 static int __init setup_isl29018_als(const struct dmi_system_id *id)
 156 {
 157         /* add isl29018 light sensor */
 158         als = add_smbus_device("lightsensor", &isl_als_device);
 159         return 0;
 160 }
 161
 162 static struct dmi_system_id __initdata chromeos_laptop_dmi_table[] = {
 163         {
 164                 .ident = "Samsung Series 5 550 - Touchpad",
 165                 .matches = {
 166                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG"),
 167                         DMI_MATCH(DMI_PRODUCT_NAME, "Lumpy"),
 168                 },
 169                 .callback = setup_cyapa_smbus_tp,
 170         },
 171         {
 172                 .ident = "Samsung Series 5 550 - Light Sensor",
 173                 .matches = {
 174                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG"),
 175                         DMI_MATCH(DMI_PRODUCT_NAME, "Lumpy"),
 176                 },
 177                 .callback = setup_isl29018_als,
 178         },
 179         {
 180                 .ident = "Acer C7 Chromebook - Touchpad",
 181                 .matches = {
 182                         DMI_MATCH(DMI_PRODUCT_NAME, "Parrot"),
 183                 },
 184                 .callback = setup_cyapa_smbus_tp,
 185         },
 186         { }
 187 };
 188 MODULE_DEVICE_TABLE(dmi, chromeos_laptop_dmi_table);
 189
 190 static int __init chromeos_laptop_init(void)
 191 {
 192         if (!dmi_check_system(chromeos_laptop_dmi_table)) {
 193                 pr_debug("%s unsupported system.\n", __func__);
 194                 return -ENODEV;
 195         }
 196         return 0;
 197 }
 198
 199 static void __exit chromeos_laptop_exit(void)
 200 {
 201         if (als)
 202                 i2c_unregister_device(als);
 203         if (tp)
 204                 i2c_unregister_device(tp);
 205 }
 206
 207 module_init(chromeos_laptop_init);
 208 module_exit(chromeos_laptop_exit);
 209
 210 MODULE_DESCRIPTION("Chrome OS Laptop driver");
 211 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
 212 MODULE_LICENSE("GPL");