From: Alain Volmat <alain.volmat@st.com>
To: Wolfram Sang <wsa@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
Pierre Yves MORDRET <pierre-yves.mordret@st.com>,
"mcoquelin.stm32@gmail.com" <mcoquelin.stm32@gmail.com>,
Alexandre TORGUE <alexandre.torgue@st.com>,
"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-stm32@st-md-mailman.stormreply.com"
<linux-stm32@st-md-mailman.stormreply.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Fabrice GASNIER <fabrice.gasnier@st.com>
Subject: Re: [PATCH 1/4] i2c: smbus: add core function handling SMBus host-notify
Date: Tue, 26 May 2020 12:23:01 +0200 [thread overview]
Message-ID: <20200526102301.GA14423@gnbcxd0016.gnb.st.com> (raw)
In-Reply-To: <20200523104624.GB3459@ninjato>
On Sat, May 23, 2020 at 10:46:25AM +0000, Wolfram Sang wrote:
>
> Adding Benjamin who mainly implemented this.
>
> On Tue, May 05, 2020 at 07:51:08AM +0200, Alain Volmat wrote:
> > SMBus Host-Notify protocol, from the adapter point of view
> > consist of receiving a message from a client, including the
> > client address and some other data.
> >
> > It can be simply handled by creating a new slave device
> > and registering a callback performing the parsing of the
> > message received from the client.
> >
> > This commit introduces two new core functions
> > * i2c_new_smbus_host_notify_device
> > * i2c_free_smbus_host_notify_device
> > that take care of registration of the new slave device and
> > callback and will call i2c_handle_smbus_host_notify once a
> > Host-Notify event is received.
>
> Yay, cool idea to use the slave interface. I like it a lot!
>
> > +static int i2c_smbus_host_notify_cb(struct i2c_client *client,
> > + enum i2c_slave_event event, u8 *val)
> > +{
> > + struct i2c_smbus_host_notify_status *status = client->dev.platform_data;
> > + int ret;
> > +
> > + switch (event) {
> > + case I2C_SLAVE_WRITE_REQUESTED:
> > + status->notify_start = true;
> > + break;
> > + case I2C_SLAVE_WRITE_RECEIVED:
> > + /* We only retrieve the first byte received (addr)
> > + * since there is currently no way to retrieve the data
> > + * parameter from the client.
>
> Maybe s/no way/no support/ ? I still wonder if we couldn't add it
> somehow. Once we find a device which needs this, of course.
Indeed. Such support can be added later on once such device is found. For the
time being I will state "no support"
>
> > + */
> > + if (!status->notify_start)
> > + break;
> > + status->addr = *val;
> > + status->notify_start = false;
> > + break;
> > + case I2C_SLAVE_STOP:
>
> What about setting 'notify_start' to false here as well? In the case of
> an incomplete write?
Ok. I will check that notify_start is false before calling host_notify
(since otherwise it will call i2c_handle_smbus_host_notify with a bad addr
value) and reset notify_start to false if it is still true.
>
> > + ret = i2c_handle_smbus_host_notify(client->adapter,
> > + status->addr);
> > + if (ret < 0) {
> > + dev_warn(&client->adapter->dev, "failed to handle host_notify (%d)\n",
> > + ret);
>
> I think we should rather add such error strings to the core if we think
> they are needed. I am not convinced they are, though.
Agreed, this error can be removed.
>
> > + return ret;
> > + }
> > + break;
> > + default:
> > + /* Only handle necessary events */
> > + break;
> > + }
> > +
> > + return 0;
> > +}
> > +
>
> Rest of the code looks good. Maybe we should compile all this only when
> I2C_SLAVE is enabled?
>
Yes, I will enclose that around I2C_SLAVE support check.
next prev parent reply other threads:[~2020-05-26 10:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 5:51 [PATCH 0/4] stm32-f7: Addition of SMBus Alert / Host-notify features Alain Volmat
2020-05-05 5:51 ` [PATCH 1/4] i2c: smbus: add core function handling SMBus host-notify Alain Volmat
2020-05-11 8:26 ` Pierre Yves MORDRET
2020-05-23 10:46 ` Wolfram Sang
2020-05-26 10:23 ` Alain Volmat [this message]
2020-05-05 5:51 ` [PATCH 2/4] i2c: addition of client reg/unreg callbacks Alain Volmat
2020-05-11 8:28 ` Pierre Yves MORDRET
2020-05-23 10:49 ` Wolfram Sang
2020-05-05 5:51 ` [PATCH 3/4] dt-bindings: i2c-stm32: add SMBus Alert bindings Alain Volmat
2020-05-13 2:19 ` Rob Herring
2020-05-13 5:42 ` Alain Volmat
2020-05-18 10:53 ` Alain Volmat
2020-05-23 10:36 ` wsa
2020-05-26 10:31 ` Alain Volmat
2020-05-05 5:51 ` [PATCH 4/4] i2c: stm32f7: Add SMBus-specific protocols support Alain Volmat
2020-05-11 8:27 ` Pierre Yves MORDRET
2020-05-23 11:01 ` Wolfram Sang
2020-05-26 10:39 ` Alain Volmat
2020-06-30 6:40 ` Wolfram Sang
2020-06-30 9:31 ` Alain Volmat
2020-06-30 15:11 ` Wolfram Sang
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