From: Wolfram Sang <wsa@kernel.org>
To: Alain Volmat <alain.volmat@st.com>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: robh+dt@kernel.org, mark.rutland@arm.com,
pierre-yves.mordret@st.com, mcoquelin.stm32@gmail.com,
alexandre.torgue@st.com, linux-i2c@vger.kernel.org,
devicetree@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, fabrice.gasnier@st.com
Subject: Re: [PATCH 1/4] i2c: smbus: add core function handling SMBus host-notify
Date: Sat, 23 May 2020 12:46:25 +0200 [thread overview]
Message-ID: <20200523104624.GB3459@ninjato> (raw)
In-Reply-To: <1588657871-14747-2-git-send-email-alain.volmat@st.com>
[-- Attachment #1: Type: text/plain, Size: 2278 bytes --]
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.
> + */
> + 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?
> + 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.
> + 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?
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2020-05-23 10:46 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 [this message]
2020-05-26 10:23 ` Alain Volmat
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200523104624.GB3459@ninjato \
--to=wsa@kernel.org \
--cc=alain.volmat@st.com \
--cc=alexandre.torgue@st.com \
--cc=benjamin.tissoires@redhat.com \
--cc=devicetree@vger.kernel.org \
--cc=fabrice.gasnier@st.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-stm32@st-md-mailman.stormreply.com \
--cc=mark.rutland@arm.com \
--cc=mcoquelin.stm32@gmail.com \
--cc=pierre-yves.mordret@st.com \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).