Re: [PATCH] Improve Alps HID Touchpad code

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Jun 21, 2016 at 07:28:32PM +0900, Masaki Ota wrote:
> From Masaki Ota <masaki.ota@jp.alps.com>
> 
> Remove the unnecessary codes.
> Add the device ID of "HID_DEVICE_ID_ALPS_U1_DUAL" to hid-ids.h
> 
> Signed-off-by: Masaki Ota <masaki.ota@jp.alps.com>
> ---
>  drivers/hid/hid-alps.c | 98 +++++++++++++++++++++-----------------------------
>  drivers/hid/hid-core.c |  3 +-
>  drivers/hid/hid-ids.h  |  1 +
>  3 files changed, 44 insertions(+), 58 deletions(-)
> 
> diff --git a/drivers/hid/hid-alps.c b/drivers/hid/hid-alps.c
> index ff64c929..e6a0e88 100644
> --- a/drivers/hid/hid-alps.c
> +++ b/drivers/hid/hid-alps.c
> @@ -15,6 +15,9 @@
>  #include <asm/unaligned.h>
>  #include "hid-ids.h"
>  
> +#define STATUS_SUCCESS	0

O is the standard success code, please use it directly.

> +#define STATUS_FAIL	1

I do not see it being used anywhere.

> +
>  /* ALPS Device Product ID */
>  #define HID_PRODUCT_ID_T3_BTNLESS	0xD0C0
>  #define HID_PRODUCT_ID_COSMO		0x1202
> @@ -98,8 +101,6 @@ struct u1_dev {
>  	u32	sp_btn_cnt;
>  };
>  
> -static struct u1_dev *priv;
> -
>  static int u1_read_write_register(struct hid_device *hdev, u32 address,
>  	u8 *read_val, u8 write_val, bool read_flag)
>  {
> @@ -108,16 +109,10 @@ static int u1_read_write_register(struct hid_device *hdev, u32 address,
>  	u8 *input;
>  	u8 *readbuf;
>  
> -	input = kzalloc(sizeof(u8)*U1_FEATURE_REPORT_LEN, GFP_KERNEL);
> +	input = kzalloc(U1_FEATURE_REPORT_LEN, GFP_KERNEL);
>  	if (!input)
>  		return -ENOMEM;
>  
> -	readbuf = kzalloc(sizeof(u8)*U1_FEATURE_REPORT_LEN, GFP_KERNEL);
> -	if (!readbuf) {
> -		kfree(input);
> -		return -ENOMEM;
> -	}
> -
>  	input[0] = U1_FEATURE_REPORT_ID;
>  	if (read_flag) {
>  		input[1] = U1_CMD_REGISTER_READ;
> @@ -136,8 +131,8 @@ static int u1_read_write_register(struct hid_device *hdev, u32 address,
>  
>  	input[7] = check_sum;
>  	ret = hid_hw_raw_request(hdev, U1_FEATURE_REPORT_ID, input,
> -			sizeof(u8)*U1_FEATURE_REPORT_LEN, HID_FEATURE_REPORT,
> -			HID_REQ_SET_REPORT);
> +			U1_FEATURE_REPORT_LEN,
> +			HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
>  
>  	if (ret < 0) {
>  		dev_err(&hdev->dev, "failed to read command (%d)\n", ret);
> @@ -145,8 +140,14 @@ static int u1_read_write_register(struct hid_device *hdev, u32 address,
>  	}
>  
>  	if (read_flag) {
> +		readbuf = kzalloc(U1_FEATURE_REPORT_LEN, GFP_KERNEL);
> +		if (!readbuf) {
> +			kfree(input);
> +			return -ENOMEM;
> +		}
> +
>  		ret = hid_hw_raw_request(hdev, U1_FEATURE_REPORT_ID, readbuf,
> -				sizeof(u8)*U1_FEATURE_REPORT_LEN,
> +				U1_FEATURE_REPORT_LEN,
>  				HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
>  
>  		if (ret < 0) {
> @@ -155,15 +156,14 @@ static int u1_read_write_register(struct hid_device *hdev, u32 address,
>  		}
>  
>  		*read_val = readbuf[6];
> +
> +		kfree(readbuf);
>  	}
>  
> -	kfree(input);
> -	kfree(readbuf);
> -	return 0;
> +	ret = STATUS_SUCCESS;
>  
>  exit:
>  	kfree(input);
> -	kfree(readbuf);
>  	return ret;
>  }
>  
> @@ -171,7 +171,7 @@ static int alps_raw_event(struct hid_device *hdev,
>  		struct hid_report *report, u8 *data, int size)
>  {
>  	int x[MAX_TOUCHES], y[MAX_TOUCHES], z[MAX_TOUCHES];

Should be unsigned I think.

> -	int i, left, right, middle;
> +	int i;
>  	short sp_x, sp_y, sp_z;
>  	struct u1_dev *hdata = hid_get_drvdata(hdev);
>  
> @@ -182,12 +182,9 @@ static int alps_raw_event(struct hid_device *hdev,
>  		break;
>  	case U1_ABSOLUTE_REPORT_ID:
>  		for (i = 0; i < MAX_TOUCHES; i++) {
> -			x[i] = (data[3+(5*i)] | (data[4+(5*i)] << 8));
> -			y[i] = (data[5+(5*i)] | (data[6+(5*i)] << 8));
> +			x[i] = get_unaligned_le16(data+3+(5*i));
> +			y[i] = get_unaligned_le16(data+5+(5*i));
>  			z[i] = data[7+(5*i)] & 0x7F;

Could use some spaces around operations. You also do not need to have
arrays for coordinates. I'd do:

			u8 *contact = &data[i * 5];
			x = get_unaligned_le16(contact + 3);
			y = get_unaligned_le16(contact + 5);
			x = contact[7] & 0x7f;


> -			left = data[1] & 0x1;
> -			right = (data[1] & 0x2) >> 1;
> -			middle = (data[1] & 0x4) >> 2;
>  
>  			input_mt_slot(hdata->input, i);
>  
> @@ -209,33 +206,37 @@ static int alps_raw_event(struct hid_device *hdev,
>  		}
>  
>  		input_mt_sync_frame(hdata->input);
> -		input_sync(hdata->input);
>  
> -		input_event(hdata->input, EV_KEY, BTN_LEFT, left);
> -		input_event(hdata->input, EV_KEY, BTN_RIGHT, right);
> -		input_event(hdata->input, EV_KEY, BTN_MIDDLE, middle);
> +		input_event(hdata->input, EV_KEY, BTN_LEFT,
> +			data[1] & 0x1);
> +		input_event(hdata->input, EV_KEY, BTN_RIGHT,
> +			(data[1] & 0x2) >> 1);
> +		input_event(hdata->input, EV_KEY, BTN_MIDDLE,
> +			(data[1] & 0x4) >> 2);

I'd rather you did:

		input_report_key(hdata->input, BTN_LEFT, data[1] & 0x1);
		input_report_key(hdata->input, BTN_RIGHT, data[1] & 0x2);
		input_report_key(hdata->input, BTN_MIDDLE, data[1] & 0x4);

and use input_report_abs() for absolute events.

> +
> +		input_sync(hdata->input);
>  
>  		return 1;
>  
>  	case U1_SP_ABSOLUTE_REPORT_ID:
> -		sp_x = (data[2] | (data[3] << 8));
> -		sp_y = (data[4] | (data[5] << 8));
> +		sp_x = get_unaligned_le16(data+2);
> +		sp_y = get_unaligned_le16(data+4);
>  		sp_z = (data[6] | data[7]) & 0x7FFF;

Where do we use sp_z?

> -		left = data[1] & 0x1;
> -		right = (data[1] & 0x2) >> 1;
> -		middle = (data[1] & 0x4) >> 2;
>  
>  		sp_x = sp_x / 8;
>  		sp_y = sp_y / 8;
>  
> -		input_event(priv->input2, EV_REL, REL_X, sp_x);
> -		input_event(priv->input2, EV_REL, REL_Y, sp_y);
> +		input_event(hdata->input2, EV_REL, REL_X, sp_x);
> +		input_event(hdata->input2, EV_REL, REL_Y, sp_y);

		input_report_rel(...);

>  
> -		input_event(priv->input2, EV_KEY, BTN_LEFT, left);
> -		input_event(priv->input2, EV_KEY, BTN_RIGHT, right);
> -		input_event(priv->input2, EV_KEY, BTN_MIDDLE, middle);
> +		input_event(hdata->input2, EV_KEY, BTN_LEFT,
> +			data[1] & 0x1);
> +		input_event(hdata->input2, EV_KEY, BTN_RIGHT,
> +			(data[1] & 0x2) >> 1);
> +		input_event(hdata->input2, EV_KEY, BTN_MIDDLE,
> +			(data[1] & 0x4) >> 2);

		input_report_key().

>  
> -		input_sync(priv->input2);
> +		input_sync(hdata->input2);
>  
>  		return 1;
>  	}
> @@ -265,15 +266,6 @@ static int alps_input_configured(struct hid_device *hdev, struct hid_input *hi)
>  	int ret;
>  	int res_x, res_y, i;
>  
> -	/* Check device product ID */
> -	switch (hdev->product) {
> -	case HID_PRODUCT_ID_U1:
> -	case HID_PRODUCT_ID_U1_DUAL:
> -		break;
> -	default:
> -		return 0;
> -	}
> -
>  	data->input = input;
>  
>  	hid_dbg(hdev, "Opening low level driver\n");
> @@ -393,20 +385,13 @@ static int alps_input_configured(struct hid_device *hdev, struct hid_input *hi)
>  	/* Stick device initialization */
>  	if (devInfo.dev_type & U1_DEVTYPE_SP_SUPPORT) {
>  
> -		priv = kzalloc(sizeof(struct u1_dev), GFP_KERNEL);
> -		if (!priv) {
> -			hid_device_io_stop(hdev);
> -			hid_hw_close(hdev);
> -			return -ENOMEM;
> -		}
> -
>  		input2 = input_allocate_device();
>  		if (!input2) {
>  			input_free_device(input2);
>  			goto exit;
>  		}
>  
> -		priv->input2 = input2;
> +		data->input2 = input2;
>  
>  		devInfo.dev_ctrl |= U1_SP_ABS_MODE;
>  		ret = u1_read_write_register(hdev, ADDRESS_U1_DEV_CTRL_1,
> @@ -444,7 +429,7 @@ static int alps_input_configured(struct hid_device *hdev, struct hid_input *hi)
>  		__set_bit(INPUT_PROP_POINTER, input2->propbit);
>  		__set_bit(INPUT_PROP_POINTING_STICK, input2->propbit);
>  
> -		if (input_register_device(priv->input2)) {
> +		if (input_register_device(data->input2)) {
>  			input_free_device(input2);
>  			goto exit;
>  		}
> @@ -495,12 +480,11 @@ static int alps_probe(struct hid_device *hdev, const struct hid_device_id *id)
>  static void alps_remove(struct hid_device *hdev)
>  {
>  	hid_hw_stop(hdev);
> -	kfree(priv);
>  }
>  
>  static const struct hid_device_id alps_id[] = {
>  	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY,
> -		USB_VENDOR_ID_ALPS_JP, HID_ANY_ID) },
> +		USB_VENDOR_ID_ALPS_JP, HID_DEVICE_ID_ALPS_U1_DUAL) },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(hid, alps_id);
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 3cdbc4b..678d8bd 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -1772,7 +1772,8 @@ static const struct hid_device_id hid_have_special_driver[] = {
>  	{ HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_RP_649) },
>  	{ HID_USB_DEVICE(USB_VENDOR_ID_ACRUX, 0x0802) },
>  	{ HID_USB_DEVICE(USB_VENDOR_ID_ACRUX, 0xf705) },
> -	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, USB_VENDOR_ID_ALPS_JP, HID_ANY_ID) },
> +	{ HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, USB_VENDOR_ID_ALPS_JP,
> +	HID_DEVICE_ID_ALPS_U1_DUAL) },
>  	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MIGHTYMOUSE) },
>  	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGICMOUSE) },
>  	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGICTRACKPAD) },
> diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> index a5a429c..c4f665d 100644
> --- a/drivers/hid/hid-ids.h
> +++ b/drivers/hid/hid-ids.h
> @@ -71,6 +71,7 @@
>  #define USB_DEVICE_ID_IBM_GAMEPAD	0x1101
>  
>  #define USB_VENDOR_ID_ALPS_JP		0x044E
> +#define HID_DEVICE_ID_ALPS_U1_DUAL	0x120B
>  
>  #define USB_VENDOR_ID_ANTON		0x1130
>  #define USB_DEVICE_ID_ANTON_TOUCH_PAD	0x3101
> -- 
> 2.7.4
> 

Thanks.

-- 
Dmitry