Commit 8399bd01 authored by Dmitry Torokhov's avatar Dmitry Torokhov Committed by Jiri Kosina
Browse files

HID: i2c-hid: define i2c_hid_read_register() and use it 



Handling simple read of device registers in __i2c_hid_command() makes it
too complicated and the need of special handling for the HID descriptor
register adds even more complexity. Instead, let's create simple
i2c_hid_read_register() helper on base of i2c_hid_xfer() and use it.

Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent dbe0dd5f

drivers/hid/i2c-hid/i2c-hid-core.c

+22 −23
Original line number Diff line number Diff line
@@ -104,14 +104,6 @@ struct i2c_hid_cmd { 
	.opcode = opcode_, .length = 4, \

	.registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)



/* fetch HID descriptor */

static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };

/* fetch report descriptors */

static const struct i2c_hid_cmd hid_report_descr_cmd = {

		.registerIndex = offsetof(struct i2c_hid_desc,

			wReportDescRegister),

		.opcode = 0x00,

		.length = 2 };

/* commands */

static const struct i2c_hid_cmd hid_reset_cmd =		{ I2C_HID_CMD(0x01) };

static const struct i2c_hid_cmd hid_get_report_cmd =	{ I2C_HID_CMD(0x02) };
@@ -243,6 +235,14 @@ static int i2c_hid_xfer(struct i2c_hid *ihid, 
	return 0;

}



static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,

				 void *buf, size_t len)

{

	*(__le16 *)ihid->cmdbuf = reg;



	return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);

}



static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,

				     int report_type, int report_id)

{
@@ -268,13 +268,8 @@ static int __i2c_hid_command(struct i2c_hid *ihid, 
	int length = command->length;

	unsigned int registerIndex = command->registerIndex;



	/* special case for hid_descr_cmd */

	if (command == &hid_descr_cmd) {

		*(__le16 *)ihid->cmdbuf = ihid->wHIDDescRegister;

	} else {

	ihid->cmdbuf[0] = ihid->hdesc_buffer[registerIndex];

	ihid->cmdbuf[1] = ihid->hdesc_buffer[registerIndex + 1];

	}



	if (length > 2) {

		length = sizeof(__le16) + /* register */
@@ -794,7 +789,8 @@ static int i2c_hid_parse(struct hid_device *hid) 


		i2c_hid_dbg(ihid, "asking HID report descriptor\n");



		ret = i2c_hid_command(ihid, &hid_report_descr_cmd,

		ret = i2c_hid_read_register(ihid,

					    ihid->hdesc.wReportDescRegister,

					    rdesc, rsize);

		if (ret) {

			hid_err(hid, "reading report descriptor failed\n");
@@ -905,7 +901,7 @@ static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 
	struct i2c_client *client = ihid->client;

	struct i2c_hid_desc *hdesc = &ihid->hdesc;

	unsigned int dsize;

	int ret;

	int error;



	/* i2c hid fetch using a fixed descriptor size (30 bytes) */

	if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
@@ -914,11 +910,14 @@ static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 
			*i2c_hid_get_dmi_i2c_hid_desc_override(client->name);

	} else {

		i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");

		ret = i2c_hid_command(ihid, &hid_descr_cmd,

				      ihid->hdesc_buffer,

				      sizeof(struct i2c_hid_desc));

		if (ret) {

			dev_err(&ihid->client->dev, "hid_descr_cmd failed\n");

		error = i2c_hid_read_register(ihid,

					      ihid->wHIDDescRegister,

					      &ihid->hdesc,

					      sizeof(ihid->hdesc));

		if (error) {

			dev_err(&ihid->client->dev,

				"failed to fetch HID descriptor: %d\n",

				error);

			return -ENODEV;

		}

	}