Platform: x86: Add Chrome OS Laptop driver
authorBenson Leung <bleung@chromium.org>
Thu, 25 Oct 2012 21:21:21 +0000 (14:21 -0700)
committerMatthew Garrett <matthew.garrett@nebula.com>
Sun, 24 Feb 2013 22:49:57 +0000 (14:49 -0800)
This adds the chromeos_laptop driver. It supports
the Cypress APA SMBUS touchpad as well as the isl29018 i2c ambient
light sensor on the Samsung Series 5 550 Chromebook.

Signed-off-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
drivers/platform/x86/Kconfig
drivers/platform/x86/Makefile
drivers/platform/x86/chromeos_laptop.c [new file with mode: 0644]

index 7ab0b2f..585db6f 100644 (file)
@@ -79,6 +79,17 @@ config ASUS_LAPTOP
 
          If you have an ACPI-compatible ASUS laptop, say Y or M here.
 
+config CHROMEOS_LAPTOP
+       tristate "Chrome OS Laptop"
+       depends on I2C
+       depends on DMI
+       ---help---
+         This driver instantiates i2c and smbus devices such as
+         light sensors and touchpads.
+
+         If you have a supported Chromebook, choose Y or M here.
+         The module will be called chromeos_laptop.
+
 config DELL_LAPTOP
        tristate "Dell Laptop Extras"
        depends on X86
index bf7e4f9..ace2b38 100644 (file)
@@ -50,3 +50,4 @@ obj-$(CONFIG_INTEL_MID_POWER_BUTTON)  += intel_mid_powerbtn.o
 obj-$(CONFIG_INTEL_OAKTRAIL)   += intel_oaktrail.o
 obj-$(CONFIG_SAMSUNG_Q10)      += samsung-q10.o
 obj-$(CONFIG_APPLE_GMUX)       += apple-gmux.o
+obj-$(CONFIG_CHROMEOS_LAPTOP)  += chromeos_laptop.o
diff --git a/drivers/platform/x86/chromeos_laptop.c b/drivers/platform/x86/chromeos_laptop.c
new file mode 100644 (file)
index 0000000..a8329c3
--- /dev/null
@@ -0,0 +1,205 @@
+/*
+ *  chromeos_laptop.c - Driver to instantiate Chromebook i2c/smbus devices.
+ *
+ *  Author : Benson Leung <bleung@chromium.org>
+ *
+ *  Copyright (C) 2012 Google, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/dmi.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#define CYAPA_TP_I2C_ADDR      0x67
+#define ISL_ALS_I2C_ADDR       0x44
+
+static struct i2c_client *als;
+static struct i2c_client *tp;
+
+const char *i2c_adapter_names[] = {
+       "SMBus I801 adapter",
+};
+
+/* Keep this enum consistent with i2c_adapter_names */
+enum i2c_adapter_type {
+       I2C_ADAPTER_SMBUS = 0,
+};
+
+static struct i2c_board_info __initdata cyapa_device = {
+       I2C_BOARD_INFO("cyapa", CYAPA_TP_I2C_ADDR),
+       .flags          = I2C_CLIENT_WAKE,
+};
+
+static struct i2c_board_info __initdata isl_als_device = {
+       I2C_BOARD_INFO("isl29018", ISL_ALS_I2C_ADDR),
+};
+
+static struct i2c_client __init *__add_probed_i2c_device(
+               const char *name,
+               int bus,
+               struct i2c_board_info *info,
+               const unsigned short *addrs)
+{
+       const struct dmi_device *dmi_dev;
+       const struct dmi_dev_onboard *dev_data;
+       struct i2c_adapter *adapter;
+       struct i2c_client *client;
+
+       if (bus < 0)
+               return NULL;
+       /*
+        * If a name is specified, look for irq platform information stashed
+        * in DMI_DEV_TYPE_DEV_ONBOARD by the Chrome OS custom system firmware.
+        */
+       if (name) {
+               dmi_dev = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, name, NULL);
+               if (!dmi_dev) {
+                       pr_err("%s failed to dmi find device %s.\n",
+                              __func__,
+                              name);
+                       return NULL;
+               }
+               dev_data = (struct dmi_dev_onboard *)dmi_dev->device_data;
+               if (!dev_data) {
+                       pr_err("%s failed to get data from dmi for %s.\n",
+                              __func__, name);
+                       return NULL;
+               }
+               info->irq = dev_data->instance;
+       }
+
+       adapter = i2c_get_adapter(bus);
+       if (!adapter) {
+               pr_err("%s failed to get i2c adapter %d.\n", __func__, bus);
+               return NULL;
+       }
+
+       /* add the i2c device */
+       client = i2c_new_probed_device(adapter, info, addrs, NULL);
+       if (!client)
+               pr_err("%s failed to register device %d-%02x\n",
+                      __func__, bus, info->addr);
+       else
+               pr_debug("%s added i2c device %d-%02x\n",
+                        __func__, bus, info->addr);
+
+       i2c_put_adapter(adapter);
+       return client;
+}
+
+static int __init __find_i2c_adap(struct device *dev, void *data)
+{
+       const char *name = data;
+       static const char *prefix = "i2c-";
+       struct i2c_adapter *adapter;
+       if (strncmp(dev_name(dev), prefix, strlen(prefix)) != 0)
+               return 0;
+       adapter = to_i2c_adapter(dev);
+       return (strncmp(adapter->name, name, strlen(name)) == 0);
+}
+
+static int __init find_i2c_adapter_num(enum i2c_adapter_type type)
+{
+       struct device *dev = NULL;
+       struct i2c_adapter *adapter;
+       const char *name = i2c_adapter_names[type];
+       /* find the adapter by name */
+       dev = bus_find_device(&i2c_bus_type, NULL, (void *)name,
+                             __find_i2c_adap);
+       if (!dev) {
+               pr_err("%s: i2c adapter %s not found on system.\n", __func__,
+                      name);
+               return -ENODEV;
+       }
+       adapter = to_i2c_adapter(dev);
+       return adapter->nr;
+}
+
+/*
+ * Probes for a device at a single address, the one provided by
+ * info->addr.
+ * Returns NULL if no device found.
+ */
+static struct i2c_client __init *add_smbus_device(const char *name,
+                                                 struct i2c_board_info *info)
+{
+       const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
+       return __add_probed_i2c_device(name,
+                                      find_i2c_adapter_num(I2C_ADAPTER_SMBUS),
+                                      info,
+                                      addr_list);
+}
+
+static int __init setup_lumpy_tp(const struct dmi_system_id *id)
+{
+       /* add cyapa touchpad on smbus */
+       tp = add_smbus_device("trackpad", &cyapa_device);
+       return 0;
+}
+
+static int __init setup_isl29018_als(const struct dmi_system_id *id)
+{
+       /* add isl29018 light sensor */
+       als = add_smbus_device("lightsensor", &isl_als_device);
+       return 0;
+}
+
+static struct dmi_system_id __initdata chromeos_laptop_dmi_table[] = {
+       {
+               .ident = "Samsung Series 5 550 - Touchpad",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG"),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Lumpy"),
+               },
+               .callback = setup_lumpy_tp,
+       },
+       {
+               .ident = "Samsung Series 5 550 - Light Sensor",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG"),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Lumpy"),
+               },
+               .callback = setup_isl29018_als,
+       },
+       { }
+};
+MODULE_DEVICE_TABLE(dmi, chromeos_laptop_dmi_table);
+
+static int __init chromeos_laptop_init(void)
+{
+       if (!dmi_check_system(chromeos_laptop_dmi_table)) {
+               pr_debug("%s unsupported system.\n", __func__);
+               return -ENODEV;
+       }
+       return 0;
+}
+
+static void __exit chromeos_laptop_exit(void)
+{
+       if (als)
+               i2c_unregister_device(als);
+       if (tp)
+               i2c_unregister_device(tp);
+}
+
+module_init(chromeos_laptop_init);
+module_exit(chromeos_laptop_exit);
+
+MODULE_DESCRIPTION("Chrome OS Laptop driver");
+MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
+MODULE_LICENSE("GPL");