Re: [PATCH] Platform: x86: Add Chrome OS Laptop driver

[Corentin Chary]

On Wed, Jul 11, 2012 at 1:03 AM, Benson Leung <bleung@xxxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxxx>
> ---
>  drivers/platform/x86/Kconfig           |   11 ++
>  drivers/platform/x86/Makefile          |    1 +
>  drivers/platform/x86/chromeos_laptop.c |  202 ++++++++++++++++++++++++++++++++
>  3 files changed, 214 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/platform/x86/chromeos_laptop.c
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 2a262f5..42a177b 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -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 (EXPERIMENTAL)"
>         depends on X86
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index bf7e4f9..ace2b38 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -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
> index 0000000..c5486f0
> --- /dev/null
> +++ b/drivers/platform/x86/chromeos_laptop.c
> @@ -0,0 +1,202 @@
> +/*
> + *  chromeos_laptop.c - Driver to instantiate Chromebook i2c/smbus devices.
> + *
> + *  Author : Benson Leung <bleung@xxxxxxxxxxxx>
> + *
> + *  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 __init struct i2c_client *__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;
> +       const char *prefix = "i2c-";
> +       struct i2c_adapter *adapter;
> +       if (strncmp(dev_name(dev), prefix, strlen(prefix)))
> +               return 0;
> +       adapter = to_i2c_adapter(dev);
> +       return !strncmp(adapter->name, name, strlen(name));
> +}
> +
> +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 __init struct i2c_client *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 const struct __initdata dmi_system_id chromeos_laptop_dmi_table[] = {
> +       {
> +               .ident = "Samsung Series 5 550 - Touchpad",
> +               .matches = {
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "Lumpy"),
> +               },
> +               .callback = setup_lumpy_tp,
> +       },
> +       {
> +               .ident = "Samsung Series 5 550 - Light Sensor",
> +               .matches = {
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "Lumpy"),
> +               },
> +               .callback = setup_isl29018_als,
> +       },
> +       { }
> +};
> +
> +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@xxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 1.7.7.3
>
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Maybe you'd like to add this for autoloading ?

MODULE_DEVICE_TABLE(dmi, chromeos_laptop_dmi_table);

-- 
Corentin Chary
http://xf.iksaif.net
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