On Tue, Jun 10, 2014 at 06:17:35AM +0100, Scot Doyle wrote:
> The chromeos_laptop module probes the first i2c adapter with a specific name
> for expected hardware. However, the Acer C720 Chromebook has two i2c
> adapters with the same name. This patch probes each i2c adapter with a
> specific name in turn, until locating the expected hardware.
>
> Thanks to Mika Westerberg for identifying the need for unique bus addresses
> within each set of identically-named adapters.
>
> Signed-off-by: Scot Doyle <lkm...@scotdoyle.com>
> CC: Benson Leung <ble...@chromium.org>
> CC: Mika Westerberg <mika.westerb...@linux.intel.com>
Few comments about style:
> ---
> diff --git a/drivers/platform/chrome/chromeos_laptop.c
> b/drivers/platform/chrome/chromeos_laptop.c
> index 7f3aad0..8382315 100644
> --- a/drivers/platform/chrome/chromeos_laptop.c
> +++ b/drivers/platform/chrome/chromeos_laptop.c
> @@ -29,6 +29,8 @@
> #include <linux/module.h>
> #include <linux/platform_device.h>
>
> +/* Note: Bus addresses must be unique within each set of identically-named
> + adapters on a board, otherwise device probing may fail. */
Check Documentation/CodingStyle about format of block comments.
> #define ATMEL_TP_I2C_ADDR 0x4b
> #define ATMEL_TP_I2C_BL_ADDR 0x25
> #define ATMEL_TS_I2C_ADDR 0x4a
> @@ -173,7 +175,7 @@ static struct i2c_client *__add_probed_i2c_device(
> /* 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",
> + pr_debug("%s did not add i2c device %d-%02x\n",
> __func__, bus, info->addr);
> else
> pr_debug("%s added i2c device %d-%02x\n",
> @@ -194,13 +196,14 @@ static int __find_i2c_adap(struct device *dev, void
> *data)
> return (strncmp(adapter->name, name, strlen(name)) == 0);
> }
>
> -static int find_i2c_adapter_num(enum i2c_adapter_type type)
> +static int find_i2c_next_adapter_num(enum i2c_adapter_type type,
> + struct device *start)
> {
> 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 the next adapter by name */
> + dev = bus_find_device(&i2c_bus_type, start, (void *)name,
> __find_i2c_adap);
> if (!dev) {
> /* Adapters may appear later. Deferred probing will retry */
> @@ -226,10 +229,17 @@ static struct i2c_client *add_probed_i2c_device(
> struct i2c_board_info *info,
> const unsigned short *addrs)
> {
> - return __add_probed_i2c_device(name,
> - find_i2c_adapter_num(type),
> - info,
> - addrs);
> + struct i2c_client *client = NULL;
> + struct device *start = NULL;
> + int adapter_num = 0;
Please add blank line here.
> + while (!client && adapter_num > -1) {
> + adapter_num = find_i2c_next_adapter_num(type, start);
> + client = __add_probed_i2c_device(name,
> + adapter_num,
> + info,
> + addrs);
Don't the above fit into one line, specifically if you call adapter_num
just num or something like that.
> + }
> + return client;
> }
>
> /*
> @@ -242,10 +252,10 @@ static struct i2c_client *add_i2c_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(type),
> - info,
> - addr_list);
> + return add_probed_i2c_device(name,
> + type,
> + info,
> + addr_list);
Same here.
> }
>
> static int setup_cyapa_tp(enum i2c_adapter_type type)
--
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