Re: [PATCH 2/3] HID: steam: add serial number information.

From: Benjamin Tissoires
Date: Wed Feb 14 2018 - 09:51:37 EST


On Tue, Feb 13, 2018 at 1:03 PM, Rodrigo Rivas Costa
<rodrigorivascosta@xxxxxxxxx> wrote:
> This device has a feature report to send and receive commands.
> Use it to get the serial number and set the device's uniq value.
>
> Signed-off-by: Rodrigo Rivas Costa <rodrigorivascosta@xxxxxxxxx>
> ---
> drivers/hid/hid-steam.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 86 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
> index 03f912ab5484..f269a986e2be 100644
> --- a/drivers/hid/hid-steam.c
> +++ b/drivers/hid/hid-steam.c
> @@ -34,12 +34,17 @@ struct steam_device {
> unsigned long quirks;
> struct work_struct work_connect;
> bool connected;
> + char serial_no[11];
> };
>
> static int steam_register(struct steam_device *steam);
> static void steam_unregister(struct steam_device *steam);
> static void steam_do_connect_event(struct steam_device *steam, bool connected);
> static void steam_do_input_event(struct steam_device *steam, u8 *data);
> +static int steam_send_report(struct steam_device *steam,
> + u8 *cmd, int size);
> +static int steam_recv_report(struct steam_device *steam,
> + u8 *data, int size);
>
> static int steam_input_open(struct input_dev *dev)
> {
> @@ -55,6 +60,78 @@ static void steam_input_close(struct input_dev *dev)
> hid_hw_close(steam->hid_dev);
> }
>
> +#define STEAM_FEATURE_REPORT_SIZE 65
> +
> +static int steam_send_report(struct steam_device *steam,
> + u8 *cmd, int size)
> +{
> + int retry;
> + int ret;
> + u8 *buf = kzalloc(STEAM_FEATURE_REPORT_SIZE, GFP_KERNEL);

Please use hid_alloc_report_buf() as sometimes we need to allocate a
slightly bigger report.

> +
> + if (!buf)
> + return -ENOMEM;
> +
> + /* The report ID is always 0 */
> + memcpy(buf + 1, cmd, size);
> +
> + /* Sometimes the wireless controller fails with EPIPE
> + * when sending a feature report.
> + * Doing a HID_REQ_GET_REPORT and waiting for a while
> + * seems to fix that.
> + */
> + for (retry = 0; retry < 10; ++retry) {
> + ret = hid_hw_raw_request(steam->hid_dev, 0,
> + buf, size + 1,
> + HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
> + if (ret != -EPIPE)
> + break;
> + dbg_hid("%s: failed, retrying (%d times)\n", __func__, retry+1);
> + steam_recv_report(steam, NULL, 0);
> + msleep(50);
> + }
> + kfree(buf);
> + return ret;
> +}
> +
> +static int steam_recv_report(struct steam_device *steam,
> + u8 *data, int size)
> +{
> + int ret;
> + u8 *buf = kzalloc(STEAM_FEATURE_REPORT_SIZE, GFP_KERNEL);

same her hid_alloc_report_buf should be used

> +
> + if (!buf)
> + return -ENOMEM;
> +
> + /* The report ID is always 0 */
> + ret = hid_hw_raw_request(steam->hid_dev, 0x00,
> + buf, STEAM_FEATURE_REPORT_SIZE,
> + HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
> + memcpy(data, buf + 1, size);
> + kfree(buf);
> + return ret;
> +}
> +
> +static int steam_get_serial(struct steam_device *steam)
> +{
> + /* Send: 0xae 0x15 0x01
> + * Recv: 0xae 0x15 0x01 serialnumber (10 chars)
> + */
> + int ret;
> + u8 cmd[] = {0xae, 0x15, 0x01};
> + u8 reply[14];
> +
> + ret = steam_send_report(steam, cmd, sizeof(cmd));
> + if (ret < 0)
> + return ret;
> + ret = steam_recv_report(steam, reply, sizeof(reply));
> + if (ret < 0)
> + return ret;
> + reply[13] = 0;
> + strcpy(steam->serial_no, reply + 3);
> + return 0;
> +}
> +
> static void steam_work_connect_cb(struct work_struct *work)
> {
> struct steam_device *steam = container_of(work, struct steam_device,
> @@ -385,7 +462,12 @@ static int steam_register(struct steam_device *steam)
>
> dbg_hid("%s\n", __func__);
>
> - hid_info(hdev, "Steam Controller connected");
> + ret = steam_get_serial(steam);
> + if (ret)
> + return ret;
> +
> + hid_info(hdev, "Steam Controller SN: '%s' connected",
> + steam->serial_no);
>
> input = input_allocate_device();
> if (!input)
> @@ -398,7 +480,7 @@ static int steam_register(struct steam_device *steam)
>
> input->name = "Steam Controller";
> input->phys = hdev->phys;
> - input->uniq = hdev->uniq;
> + input->uniq = steam->serial_no;
> input->id.bustype = hdev->bus;
> input->id.vendor = hdev->vendor;
> input->id.product = hdev->product;
> @@ -447,7 +529,8 @@ static void steam_unregister(struct steam_device *steam)
> dbg_hid("%s\n", __func__);
>
> if (steam->input_dev) {
> - hid_info(steam->hid_dev, "Steam Controller disconnected");
> + hid_info(steam->hid_dev, "Steam Controller SN: '%s' disconnected",
> + steam->serial_no);
> input_unregister_device(steam->input_dev);
> steam->input_dev = NULL;
> }
> --
> 2.16.1
>

Rest is OK (minus the multi lines comments as pointed in 1/3)

Cheers,
Benjamin