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Message-Id: <20220118072628.1617172-10-dmitry.torokhov@gmail.com>
Date: Mon, 17 Jan 2022 23:26:25 -0800
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Jiri Kosina <jikos@...nel.org>,
Benjamin Tissoires <benjamin.tissoires@...hat.com>
Cc: Angela Czubak <acz@...ihalf.com>, linux-input@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 09/12] HID: i2c-hid: rework i2c_hid_get_report() to use i2c_hid_xfer()
Explicitly prepare command for i2c_hid_get_report() which makes the logic
clearer and allows us to get rid of __i2c_hid_command() and related command
definitions.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
drivers/hid/i2c-hid/i2c-hid-core.c | 150 ++++++++++++-----------------
1 file changed, 59 insertions(+), 91 deletions(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 1515fc892e61..433b6692f277 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -94,29 +94,6 @@ struct i2c_hid_desc {
__le32 reserved;
} __packed;
-struct i2c_hid_cmd {
- unsigned int registerIndex;
- __u8 opcode;
- unsigned int length;
-};
-
-#define I2C_HID_CMD(opcode_) \
- .opcode = opcode_, .length = 4, \
- .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
-
-/* commands */
-static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) };
-
-/*
- * These definitions are not used here, but are defined by the spec.
- * Keeping them here for documentation purposes.
- *
- * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
- * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
- * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
- * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
- */
-
/* The main device structure */
struct i2c_hid {
struct i2c_client *client; /* i2c client */
@@ -258,52 +235,62 @@ static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
return length;
}
-static int __i2c_hid_command(struct i2c_hid *ihid,
- const struct i2c_hid_cmd *command, u8 reportID,
- u8 reportType, u8 *args, int args_len,
- unsigned char *buf_recv, int data_len)
+static int i2c_hid_get_report(struct i2c_hid *ihid,
+ u8 report_type, u8 report_id,
+ u8 *recv_buf, size_t recv_len)
{
- int length = command->length;
- unsigned int registerIndex = command->registerIndex;
-
- ihid->cmdbuf[0] = ihid->hdesc_buffer[registerIndex];
- ihid->cmdbuf[1] = ihid->hdesc_buffer[registerIndex + 1];
+ size_t length = 0;
+ size_t ret_count;
+ int error;
- if (length > 2) {
- length = sizeof(__le16) + /* register */
- i2c_hid_encode_command(ihid->cmdbuf + sizeof(__le16),
- command->opcode,
- reportType, reportID);
- }
+ i2c_hid_dbg(ihid, "%s\n", __func__);
- memcpy(ihid->cmdbuf + length, args, args_len);
- length += args_len;
+ /* Command register goes first */
+ *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
+ length += sizeof(__le16);
+ /* Next is GET_REPORT command */
+ length += i2c_hid_encode_command(ihid->cmdbuf + length,
+ I2C_HID_OPCODE_GET_REPORT,
+ report_type, report_id);
+ /*
+ * Device will send report data through data register. Because
+ * command can be either 2 or 3 bytes destination for the data
+ * register may be not aligned.
+ */
+ put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
+ ihid->cmdbuf + length);
+ length += sizeof(__le16);
- return i2c_hid_xfer(ihid, ihid->cmdbuf, length, buf_recv, data_len);
-}
+ /*
+ * In addition to report data device will supply data length
+ * in the first 2 bytes of the response, so adjust .
+ */
+ error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
+ ihid->rawbuf, recv_len + sizeof(__le16));
+ if (error) {
+ dev_err(&ihid->client->dev,
+ "failed to set a report to device: %d\n", error);
+ return error;
+ }
-static int i2c_hid_get_report(struct i2c_hid *ihid, u8 reportType,
- u8 reportID, unsigned char *buf_recv, int data_len)
-{
- u8 args[2];
- int ret;
- int args_len = 0;
- u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
+ /* The buffer is sufficiently aligned */
+ ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
- i2c_hid_dbg(ihid, "%s\n", __func__);
+ /* Check for empty report response */
+ if (ret_count <= sizeof(__le16))
+ return 0;
- args[args_len++] = readRegister & 0xFF;
- args[args_len++] = readRegister >> 8;
+ recv_len = min(recv_len, ret_count - sizeof(__le16));
+ memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
- ret = __i2c_hid_command(ihid, &hid_get_report_cmd, reportID,
- reportType, args, args_len, buf_recv, data_len);
- if (ret) {
+ if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
dev_err(&ihid->client->dev,
- "failed to retrieve report from device.\n");
- return ret;
+ "device returned incorrect report (%d vs %d expected)\n",
+ recv_buf[0], report_id);
+ return -EINVAL;
}
- return 0;
+ return recv_len;
}
static size_t i2c_hid_format_report(u8 *buf, int report_id,
@@ -651,13 +638,12 @@ static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
}
static int i2c_hid_get_raw_report(struct hid_device *hid,
- unsigned char report_number, __u8 *buf, size_t count,
- unsigned char report_type)
+ u8 report_type, u8 report_id,
+ u8 *buf, size_t count)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
- size_t ret_count, ask_count;
- int ret;
+ int ret_count;
if (report_type == HID_OUTPUT_REPORT)
return -EINVAL;
@@ -667,42 +653,24 @@ static int i2c_hid_get_raw_report(struct hid_device *hid,
* not have the report ID that the upper layers expect, so we need
* to stash it the buffer ourselves and adjust the data size.
*/
- if (!report_number) {
+ if (!report_id) {
buf[0] = 0;
buf++;
count--;
}
- /* +2 bytes to include the size of the reply in the query buffer */
- ask_count = min(count + 2, (size_t)ihid->bufsize);
-
- ret = i2c_hid_get_report(ihid,
+ ret_count = i2c_hid_get_report(ihid,
report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
- report_number, ihid->rawbuf, ask_count);
-
- if (ret < 0)
- return ret;
-
- ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
-
- if (ret_count <= 2)
- return 0;
-
- ret_count = min(ret_count, ask_count);
-
- /* The query buffer contains the size, dropping it in the reply */
- count = min(count, ret_count - 2);
- memcpy(buf, ihid->rawbuf + 2, count);
+ report_id, buf, count);
- if (!report_number)
- count++;
+ if (ret_count > 0 && !report_id)
+ ret_count++;
- return count;
+ return ret_count;
}
-static int i2c_hid_output_raw_report(struct hid_device *hid,
- const u8 *buf, size_t count,
- u8 report_type, bool do_set)
+static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
+ const u8 *buf, size_t count, bool do_set)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
@@ -735,7 +703,7 @@ static int i2c_hid_output_raw_report(struct hid_device *hid,
static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
{
- return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
+ return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
false);
}
@@ -745,11 +713,11 @@ static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
{
switch (reqtype) {
case HID_REQ_GET_REPORT:
- return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
+ return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
case HID_REQ_SET_REPORT:
if (buf[0] != reportnum)
return -EINVAL;
- return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
+ return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
default:
return -EIO;
}
--
2.34.1.703.g22d0c6ccf7-goog
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