From: Heiner Kallweit <hkallweit1@gmail.com>
To: Wolfram Sang <wsa@kernel.org>, Andi Shyti <andi.shyti@kernel.org>,
Jean Delvare <jdelvare@suse.com>
Cc: "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>
Subject: [PATCH] i2c: i801: Call i2c_register_spd for muxed child segments
Date: Tue, 26 Mar 2024 21:42:44 +0100 [thread overview]
Message-ID: <f9df04f6-9dc2-4874-bc6c-473dc3d692b9@gmail.com> (raw)
Once the gpio mux driver binds to the "i2c-mux-gpio" platform device,
this creates the i2c adapters for the muxed child segments.
We can use the bus notifier mechanism to check for creation of the
child i2d adapters, and call i2c_register_spd() for them. This allows
to detect all DIMM's on systems with more than 8 memory slots.
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
- Rebased version of a RFC patch
- Sent as RFT to lkml, but no feedback after 3 weeks.
So give it enough time in linux-next before 6.10-rc1.
---
drivers/i2c/busses/i2c-i801.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 79870dd7a..4294c0c63 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -105,6 +105,7 @@
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
#include <linux/i2c-smbus.h>
#include <linux/acpi.h>
#include <linux/io.h>
@@ -291,6 +292,7 @@ struct i801_priv {
#if IS_ENABLED(CONFIG_I2C_MUX_GPIO) && defined CONFIG_DMI
struct platform_device *mux_pdev;
struct gpiod_lookup_table *lookup;
+ struct notifier_block mux_notifier_block;
#endif
struct platform_device *tco_pdev;
@@ -1394,6 +1396,23 @@ static const struct dmi_system_id mux_dmi_table[] = {
{ }
};
+static int i801_notifier_call(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct i801_priv *priv = container_of(nb, struct i801_priv, mux_notifier_block);
+ struct device *dev = data;
+
+ if (action != BUS_NOTIFY_ADD_DEVICE ||
+ dev->type != &i2c_adapter_type ||
+ i2c_root_adapter(dev) != &priv->adapter)
+ return NOTIFY_DONE;
+
+ /* Call i2c_register_spd for muxed child segments */
+ i2c_register_spd(to_i2c_adapter(dev));
+
+ return NOTIFY_OK;
+}
+
/* Setup multiplexing if needed */
static void i801_add_mux(struct i801_priv *priv)
{
@@ -1430,6 +1449,9 @@ static void i801_add_mux(struct i801_priv *priv)
mux_config->gpios[i], "mux", 0);
gpiod_add_lookup_table(lookup);
+ priv->mux_notifier_block.notifier_call = i801_notifier_call;
+ if (bus_register_notifier(&i2c_bus_type, &priv->mux_notifier_block))
+ return;
/*
* Register the mux device, we use PLATFORM_DEVID_NONE here
* because since we are referring to the GPIO chip by name we are
@@ -1451,6 +1473,7 @@ static void i801_add_mux(struct i801_priv *priv)
static void i801_del_mux(struct i801_priv *priv)
{
+ bus_unregister_notifier(&i2c_bus_type, &priv->mux_notifier_block);
platform_device_unregister(priv->mux_pdev);
gpiod_remove_lookup_table(priv->lookup);
}
--
2.44.0
next reply other threads:[~2024-03-26 20:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-26 20:42 Heiner Kallweit [this message]
2024-03-31 0:27 ` [PATCH] i2c: i801: Call i2c_register_spd for muxed child segments Andi Shyti
2024-04-03 19:18 ` Heiner Kallweit
2024-04-03 23:24 ` Andi Shyti
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=f9df04f6-9dc2-4874-bc6c-473dc3d692b9@gmail.com \
--to=hkallweit1@gmail.com \
--cc=andi.shyti@kernel.org \
--cc=jdelvare@suse.com \
--cc=linux-i2c@vger.kernel.org \
--cc=wsa@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 read-only IMAP folder(s) and NNTP newsgroup(s).