2023-06-01 03:54:19

by David Wu

[permalink] [raw]
Subject: [PATCH] i2c: Devices which have some i2c addr can work in same i2c bus

From: Zhang aihui <[email protected]>

If i2c slave devices don't work at the same time, which have
the same i2c addr, it would register two devices, can make them
working.

Change-Id: I1bfb7783924b08bdc6e12bf47c2de01bdac7c2e2
Signed-off-by: Zhang aihui <[email protected]>
Signed-off-by: David Wu <[email protected]>
---
drivers/i2c/i2c-core-base.c | 51 +++++++++++++++++++++++++++++--------
1 file changed, 41 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index ae3af738b03f..53a8141e6238 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -62,6 +62,7 @@
static DEFINE_MUTEX(core_lock);
static DEFINE_IDR(i2c_adapter_idr);

+static int i2c_check_addr_ex(struct i2c_adapter *adapter, int addr);
static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);

static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
@@ -849,7 +850,8 @@ static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,

static void i2c_dev_set_name(struct i2c_adapter *adap,
struct i2c_client *client,
- struct i2c_board_info const *info)
+ struct i2c_board_info const *info,
+ int status)
{
struct acpi_device *adev = ACPI_COMPANION(&client->dev);

@@ -863,8 +865,12 @@ static void i2c_dev_set_name(struct i2c_adapter *adap,
return;
}

- dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
- i2c_encode_flags_to_addr(client));
+ if (status == 0)
+ dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
+ i2c_encode_flags_to_addr(client));
+ else
+ dev_set_name(&client->dev, "%d-%04x-%01x", i2c_adapter_id(adap),
+ i2c_encode_flags_to_addr(client), status);
}

int i2c_dev_irq_from_resources(const struct resource *resources,
@@ -940,9 +946,11 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
}

/* Check for address business */
- status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
+ status = i2c_check_addr_ex(adap, i2c_encode_flags_to_addr(client));
if (status)
- goto out_err;
+ dev_err(&adap->dev,
+ "%d i2c clients have been registered at 0x%02x",
+ status, client->addr);

client->dev.parent = &client->adapter->dev;
client->dev.bus = &i2c_bus_type;
@@ -951,7 +959,7 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
client->dev.fwnode = info->fwnode;

device_enable_async_suspend(&client->dev);
- i2c_dev_set_name(adap, client, info);
+ i2c_dev_set_name(adap, client, info, status);

if (info->swnode) {
status = device_add_software_node(&client->dev, info->swnode);
@@ -976,10 +984,6 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
device_remove_software_node(&client->dev);
out_err_put_of_node:
of_node_put(info->of_node);
-out_err:
- dev_err(&adap->dev,
- "Failed to register i2c client %s at 0x%02x (%d)\n",
- client->name, client->addr, status);
out_err_silent:
kfree(client);
return ERR_PTR(status);
@@ -1988,6 +1992,33 @@ EXPORT_SYMBOL(i2c_del_driver);

/* ------------------------------------------------------------------------- */

+struct i2c_addr_cnt {
+ int addr;
+ int cnt;
+};
+
+static int __i2c_check_addr_ex(struct device *dev, void *addrp)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_addr_cnt *addrinfo = (struct i2c_addr_cnt *)addrp;
+ int addr = addrinfo->addr;
+
+ if (client && client->addr == addr)
+ addrinfo->cnt++;
+
+ return 0;
+}
+
+static int i2c_check_addr_ex(struct i2c_adapter *adapter, int addr)
+{
+ struct i2c_addr_cnt addrinfo;
+
+ addrinfo.addr = addr;
+ addrinfo.cnt = 0;
+ device_for_each_child(&adapter->dev, &addrinfo, __i2c_check_addr_ex);
+ return addrinfo.cnt;
+}
+
struct i2c_cmd_arg {
unsigned cmd;
void *arg;
--
2.25.1



2023-06-05 21:02:15

by Andi Shyti

[permalink] [raw]
Subject: Re: [PATCH] i2c: Devices which have some i2c addr can work in same i2c bus

Hi David,

On Thu, Jun 01, 2023 at 11:34:23AM +0800, David Wu wrote:
> From: Zhang aihui <[email protected]>
>
> If i2c slave devices don't work at the same time, which have
> the same i2c addr, it would register two devices, can make them
> working.

can you please rephrase this?

I understand you want to register multiple devices, how is this
going to work in hardware?

> Change-Id: I1bfb7783924b08bdc6e12bf47c2de01bdac7c2e2

please drop the Change-Id

> Signed-off-by: Zhang aihui <[email protected]>
> Signed-off-by: David Wu <[email protected]>
> ---
> drivers/i2c/i2c-core-base.c | 51 +++++++++++++++++++++++++++++--------
> 1 file changed, 41 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> index ae3af738b03f..53a8141e6238 100644
> --- a/drivers/i2c/i2c-core-base.c
> +++ b/drivers/i2c/i2c-core-base.c
> @@ -62,6 +62,7 @@
> static DEFINE_MUTEX(core_lock);
> static DEFINE_IDR(i2c_adapter_idr);
>
> +static int i2c_check_addr_ex(struct i2c_adapter *adapter, int addr);
> static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
>
> static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);
> @@ -849,7 +850,8 @@ static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
>
> static void i2c_dev_set_name(struct i2c_adapter *adap,
> struct i2c_client *client,
> - struct i2c_board_info const *info)
> + struct i2c_board_info const *info,
> + int status)

what exactly is status, is it a counter? If so, please call it
count or similar.

> {
> struct acpi_device *adev = ACPI_COMPANION(&client->dev);
>
> @@ -863,8 +865,12 @@ static void i2c_dev_set_name(struct i2c_adapter *adap,
> return;
> }
>
> - dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
> - i2c_encode_flags_to_addr(client));
> + if (status == 0)
> + dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
> + i2c_encode_flags_to_addr(client));
> + else
> + dev_set_name(&client->dev, "%d-%04x-%01x", i2c_adapter_id(adap),
> + i2c_encode_flags_to_addr(client), status);
> }
>
> int i2c_dev_irq_from_resources(const struct resource *resources,
> @@ -940,9 +946,11 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
> }
>
> /* Check for address business */
> - status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
> + status = i2c_check_addr_ex(adap, i2c_encode_flags_to_addr(client));

"status" as such was indicating that the device is busy, i.e. the
device exists. If you want to use it as a counter, then make
another variable, u8, possibly.

> if (status)
> - goto out_err;
> + dev_err(&adap->dev,
> + "%d i2c clients have been registered at 0x%02x",

I think rather than dev_err() it should be a dev_warn() (or
dev_info() as the message doesn't sound very threatening).

dev_err() should be normally followed by a failure. Perhaps to
make it sound more as a warning the message should be:

"client %d is already registere in 0x%02x\n"

Andi

> + status, client->addr);