Re: [PATCH v2] ACPI: surface3_power: MSHW0011 rev-eng implementation

From: Hans de Goede
Date: Fri Jun 30 2017 - 11:44:09 EST


Hi,

On 30-06-17 17:26, Benjamin Tissoires wrote:
On Jun 30 2017 or thereabouts, Hans de Goede wrote:

<snip>

+static int mshw0011_i2c_resource_lookup(struct mshw0011_data *cdata,
+ unsigned int index)
+{
+ struct i2c_client *client = cdata->adp1;
+ struct acpi_device *adev = ACPI_COMPANION(&client->dev);
+ struct mshw0011_lookup lookup = {
+ .cdata = cdata,
+ .index = index,
+ };
+ struct list_head res_list;
+ int ret;
+
+ INIT_LIST_HEAD(&res_list);
+
+ ret = acpi_dev_get_resources(adev, &res_list, acpi_find_i2c, &lookup);
+ if (ret < 0)
+ return ret;
+
+ acpi_dev_free_resource_list(&res_list);
+
+ if (!lookup.addr)
+ return -ENOENT;
+
+ return lookup.addr;
+}

Strange you have above functions here. It's a copy paste from I2C > core. Please, think about way of deduplicating it.

Right, this is something I can actually help with. When implementing the
INT33FE support (*) I also was dealing with an ACPI node with more then 1
I2cSerialBus type resource and I needed not just an i2c-client for the
first one (which the i2c-core gives us) but also for the others.

In 4.12 there is an i2c_acpi_new_device function which you can use
to create an i2c-client for the second i2c address you want to communicate
with, here is an example usage:

struct i2c_board_info board_info;

memset(&board_info, 0, sizeof(board_info));
strlcpy(board_info.type, "MSHW0011-bat0", I2C_NAME_SIZE);
bat0 = i2c_acpi_new_device(dev, 1, &board_info);

And then you can use bat0 to communicate to the other address,
as before, while dropping a whole bunch of copy-pasted code :)

Thanks for the tip. I wrote this code more than a year ago IIRC, and
there might not be those facilities at the time.

Correct I hit the same problem with the INT33FE device and decided
to fix this properly :) The i2c_acpi_new_device function is new
in 4.12 .

Regards,

Hans