Re: [PATCH v2] HID: i2c-hid: add ACPI support
From: Benjamin Tissoires
Date: Wed Jan 09 2013 - 09:49:12 EST
Hi Mika,
On Wed, Jan 9, 2013 at 3:43 PM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> The HID over I2C protocol specification states that when the device is
> enumerated from ACPI the HID descriptor address can be obtained by
> executing "_DSM" for the device with function 1. Enable this.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
I'm eager to test it (hopefully next week).
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Thanks,
Benjamin
> ---
> Changes to previous version:
>
> * platform data is embedded into struct i2c_hid
> * i2c_hid_acpi_pdata() returns error codes or 0 on success
> * i2c_hid_acpi_pdata() prints out errors if _DSM execution fails or
> returns something we don't understand
> * constify i2c_hid_acpi_match
> * set the hid device ACPI handle
>
> We still don't handle the GpioInt in case client->irq is not set but I
> didn't want to implement it now as I'm unable to test it. So this only
> works if the ACPI device has an Interrupt or IRQ resource set.
>
> drivers/hid/i2c-hid/i2c-hid.c | 87 ++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 81 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> index 9ef22244..9e46e42 100644
> --- a/drivers/hid/i2c-hid/i2c-hid.c
> +++ b/drivers/hid/i2c-hid/i2c-hid.c
> @@ -34,6 +34,7 @@
> #include <linux/kernel.h>
> #include <linux/hid.h>
> #include <linux/mutex.h>
> +#include <linux/acpi.h>
>
> #include <linux/i2c/i2c-hid.h>
>
> @@ -139,6 +140,8 @@ struct i2c_hid {
> unsigned long flags; /* device flags */
>
> wait_queue_head_t wait; /* For waiting the interrupt */
> +
> + struct i2c_hid_platform_data pdata;
> };
>
> static int __i2c_hid_command(struct i2c_client *client,
> @@ -810,6 +813,70 @@ static int __devinit i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
> return 0;
> }
>
> +#ifdef CONFIG_ACPI
> +static int i2c_hid_acpi_pdata(struct i2c_client *client,
> + struct i2c_hid_platform_data *pdata)
> +{
> + static u8 i2c_hid_guid[] = {
> + 0xF7, 0xF6, 0xDF, 0x3C, 0x67, 0x42, 0x55, 0x45,
> + 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE,
> + };
> + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
> + union acpi_object params[4], *obj;
> + struct acpi_object_list input;
> + struct acpi_device *adev;
> + acpi_handle handle;
> +
> + handle = ACPI_HANDLE(&client->dev);
> + if (!handle || acpi_bus_get_device(handle, &adev))
> + return -ENODEV;
> +
> + input.count = ARRAY_SIZE(params);
> + input.pointer = params;
> +
> + params[0].type = ACPI_TYPE_BUFFER;
> + params[0].buffer.length = sizeof(i2c_hid_guid);
> + params[0].buffer.pointer = i2c_hid_guid;
> + params[1].type = ACPI_TYPE_INTEGER;
> + params[1].integer.value = 1;
> + params[2].type = ACPI_TYPE_INTEGER;
> + params[2].integer.value = 1; /* HID function */
> + params[3].type = ACPI_TYPE_INTEGER;
> + params[3].integer.value = 0;
> +
> + if (ACPI_FAILURE(acpi_evaluate_object(handle, "_DSM", &input, &buf))) {
> + dev_err(&client->dev, "device _DSM execution failed\n");
> + return -ENODEV;
> + }
> +
> + obj = (union acpi_object *)buf.pointer;
> + if (obj->type != ACPI_TYPE_INTEGER) {
> + dev_err(&client->dev, "device _DSM returned invalid type: %d\n",
> + obj->type);
> + kfree(buf.pointer);
> + return -EINVAL;
> + }
> +
> + pdata->hid_descriptor_address = obj->integer.value;
> +
> + kfree(buf.pointer);
> + return 0;
> +}
> +
> +static const struct acpi_device_id i2c_hid_acpi_match[] = {
> + {"ACPI0C50", 0 },
> + {"PNP0C50", 0 },
> + { },
> +};
> +MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
> +#else
> +static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
> + struct i2c_hid_platform_data *pdata)
> +{
> + return -ENODEV;
> +}
> +#endif
> +
> static int __devinit i2c_hid_probe(struct i2c_client *client,
> const struct i2c_device_id *dev_id)
> {
> @@ -821,11 +888,6 @@ static int __devinit i2c_hid_probe(struct i2c_client *client,
>
> dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
>
> - if (!platform_data) {
> - dev_err(&client->dev, "HID register address not provided\n");
> - return -EINVAL;
> - }
> -
> if (!client->irq) {
> dev_err(&client->dev,
> "HID over i2c has not been provided an Int IRQ\n");
> @@ -836,11 +898,22 @@ static int __devinit i2c_hid_probe(struct i2c_client *client,
> if (!ihid)
> return -ENOMEM;
>
> + if (!platform_data) {
> + ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
> + if (ret) {
> + dev_err(&client->dev,
> + "HID register address not provided\n");
> + goto err;
> + }
> + } else {
> + ihid->pdata = *platform_data;
> + }
> +
> i2c_set_clientdata(client, ihid);
>
> ihid->client = client;
>
> - hidRegister = platform_data->hid_descriptor_address;
> + hidRegister = ihid->pdata.hid_descriptor_address;
> ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
>
> init_waitqueue_head(&ihid->wait);
> @@ -873,6 +946,7 @@ static int __devinit i2c_hid_probe(struct i2c_client *client,
> hid->hid_get_raw_report = i2c_hid_get_raw_report;
> hid->hid_output_raw_report = i2c_hid_output_raw_report;
> hid->dev.parent = &client->dev;
> + ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
> hid->bus = BUS_I2C;
> hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
> hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
> @@ -964,6 +1038,7 @@ static struct i2c_driver i2c_hid_driver = {
> .name = "i2c_hid",
> .owner = THIS_MODULE,
> .pm = &i2c_hid_pm,
> + .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
> },
>
> .probe = i2c_hid_probe,
> --
> 1.7.10.4
>
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