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

[Andrew Duggan]

On Wed, Mar 16, 2016 at 9:39 AM, Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> 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@xxxxxxxxxx>

Tested-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>

> ---
>
> 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.
> --
> 2.5.0
>
> --
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