Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-22 20:22:09 +00:00
Code Issues Packages Projects Releases Wiki Activity

i2c: i801: Call i2c_register_spd for muxed child segments

Browse Source 
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 i2c 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>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
This commit is contained in:
Heiner Kallweit 2024-03-26 21:42:44 +01:00 committed by Andi Shyti
parent 5bffbda7ad
commit 893fef0bc6
1 changed files with 23 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/i2c/busses/i2c-i801.c
View File

@ -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);
}