From 8399bd01026eab803d6ebb5372cf28b5e1f335f8 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 17 Jan 2022 23:26:22 -0800 Subject: [PATCH] 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: Dmitry Torokhov Tested-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- drivers/hid/i2c-hid/i2c-hid-core.c | 45 +++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 23 deletions(-) diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c index 856778d..32d275d 100644 --- a/drivers/hid/i2c-hid/i2c-hid-core.c +++ b/drivers/hid/i2c-hid/i2c-hid-core.c @@ -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; } } -- 2.7.4