Re: [PATCH v6 1/4] i2c: add a protocol parameter to the alert callback

[Corey Minyard <minyard@acm.org>]

Looks ok to me.  For IPMI:

Acked-by: Corey Minyard <cminyard@mvista.com>

On 03/16/2016 11:39 AM, Benjamin Tissoires wrote:
> .alert() is meant to be generic, but there is currently no way
> for the device driver to know which protocol generated the alert.
> Add a parameter in .alert() to help the device driver to understand
> what is given in data.
>
> This patch is required to have the support of SMBus Host Notify protocol
> through .alert().
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> ---
>
> new in v2
>
> changes in v3:
> - added also lm90.c to support the new API
>
> no changes in v4
>
> no changes in v5
>
> changes in v6:
> - made sure lm90 also checks for the type of alert first
>
>   drivers/char/ipmi/ipmi_ssif.c | 6 +++++-
>   drivers/hwmon/lm90.c          | 6 +++++-
>   drivers/i2c/i2c-smbus.c       | 3 ++-
>   include/linux/i2c.h           | 7 ++++++-
>   4 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
> index 5f1c3d0..1d67fa3 100644
> --- a/drivers/char/ipmi/ipmi_ssif.c
> +++ b/drivers/char/ipmi/ipmi_ssif.c
> @@ -568,12 +568,16 @@ static void retry_timeout(unsigned long data)
>   }
>   
>   
> -static void ssif_alert(struct i2c_client *client, unsigned int data)
> +static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
> +		       unsigned int data)
>   {
>   	struct ssif_info *ssif_info = i2c_get_clientdata(client);
>   	unsigned long oflags, *flags;
>   	bool do_get = false;
>   
> +	if (type != I2C_PROTOCOL_SMBUS_ALERT)
> +		return;
> +
>   	ssif_inc_stat(ssif_info, alerts);
>   
>   	flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
> diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
> index c9ff08d..a00fd38 100644
> --- a/drivers/hwmon/lm90.c
> +++ b/drivers/hwmon/lm90.c
> @@ -1624,10 +1624,14 @@ static int lm90_remove(struct i2c_client *client)
>   	return 0;
>   }
>   
> -static void lm90_alert(struct i2c_client *client, unsigned int flag)
> +static void lm90_alert(struct i2c_client *client, enum i2c_alert_protocol type,
> +		       unsigned int flag)
>   {
>   	u16 alarms;
>   
> +	if (type != I2C_PROTOCOL_SMBUS_ALERT)
> +		return;
> +
>   	if (lm90_is_tripped(client, &alarms)) {
>   		/*
>   		 * Disable ALERT# output, because these chips don't implement
> diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
> index abb55d3..3b6765a 100644
> --- a/drivers/i2c/i2c-smbus.c
> +++ b/drivers/i2c/i2c-smbus.c
> @@ -56,7 +56,8 @@ static int smbus_do_alert(struct device *dev, void *addrp)
>   	if (client->dev.driver) {
>   		driver = to_i2c_driver(client->dev.driver);
>   		if (driver->alert)
> -			driver->alert(client, data->flag);
> +			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT,
> +				      data->flag);
>   		else
>   			dev_warn(&client->dev, "no driver alert()!\n");
>   	} else
> diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> index 200cf13b..baae02a 100644
> --- a/include/linux/i2c.h
> +++ b/include/linux/i2c.h
> @@ -126,6 +126,10 @@ i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
>   					  u8 command, u8 length, u8 *values);
>   #endif /* I2C */
>   
> +enum i2c_alert_protocol {
> +	I2C_PROTOCOL_SMBUS_ALERT,
> +};
> +
>   /**
>    * struct i2c_driver - represent an I2C device driver
>    * @class: What kind of i2c device we instantiate (for detect)
> @@ -181,7 +185,8 @@ struct i2c_driver {
>   	 * For the SMBus alert protocol, there is a single bit of data passed
>   	 * as the alert response's low bit ("event flag").
>   	 */
> -	void (*alert)(struct i2c_client *, unsigned int data);
> +	void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol,
> +		      unsigned int data);
>   
>   	/* a ioctl like command that can be used to perform specific functions
>   	 * with the device.