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

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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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Dmitry Torokhov 2022-01-17 23:26:22 -08:00 committed by Jiri Kosina
parent dbe0dd5fd2
commit 8399bd0102
1 changed files with 22 additions and 23 deletions
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45
drivers/hid/i2c-hid/i2c-hid-core.c
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@ -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];
}
ihid->cmdbuf[0] = ihid->hdesc_buffer[registerIndex];
ihid->cmdbuf[1] = ihid->hdesc_buffer[registerIndex + 1];
if (length > 2) {
length = sizeof(__le16) + /* register */
@ -794,8 +789,9 @@ 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,
rdesc, rsize);
ret = i2c_hid_read_register(ihid,
ihid->hdesc.wReportDescRegister,
rdesc, rsize);
if (ret) {
hid_err(hid, "reading report descriptor failed\n");
kfree(rdesc);
@ -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;
}
}