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path: root/drivers/hid/hid-mcp2221.c
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Diffstat (limited to 'drivers/hid/hid-mcp2221.c')
-rw-r--r--drivers/hid/hid-mcp2221.c72
1 files changed, 50 insertions, 22 deletions
diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c
index aef0785c91..f9cceaeffd 100644
--- a/drivers/hid/hid-mcp2221.c
+++ b/drivers/hid/hid-mcp2221.c
@@ -49,6 +49,7 @@ enum {
MCP2221_I2C_MASK_ADDR_NACK = 0x40,
MCP2221_I2C_WRADDRL_SEND = 0x21,
MCP2221_I2C_ADDR_NACK = 0x25,
+ MCP2221_I2C_READ_PARTIAL = 0x54,
MCP2221_I2C_READ_COMPL = 0x55,
MCP2221_ALT_F_NOT_GPIOV = 0xEE,
MCP2221_ALT_F_NOT_GPIOD = 0xEF,
@@ -187,6 +188,25 @@ static int mcp_cancel_last_cmd(struct mcp2221 *mcp)
return mcp_send_data_req_status(mcp, mcp->txbuf, 8);
}
+/* Check if the last command succeeded or failed and return the result.
+ * If the command did fail, cancel that command which will free the i2c bus.
+ */
+static int mcp_chk_last_cmd_status_free_bus(struct mcp2221 *mcp)
+{
+ int ret;
+
+ ret = mcp_chk_last_cmd_status(mcp);
+ if (ret) {
+ /* The last command was a failure.
+ * Send a cancel which will also free the bus.
+ */
+ usleep_range(980, 1000);
+ mcp_cancel_last_cmd(mcp);
+ }
+
+ return ret;
+}
+
static int mcp_set_i2c_speed(struct mcp2221 *mcp)
{
int ret;
@@ -241,7 +261,7 @@ static int mcp_i2c_write(struct mcp2221 *mcp,
usleep_range(980, 1000);
if (last_status) {
- ret = mcp_chk_last_cmd_status(mcp);
+ ret = mcp_chk_last_cmd_status_free_bus(mcp);
if (ret)
return ret;
}
@@ -278,6 +298,7 @@ static int mcp_i2c_smbus_read(struct mcp2221 *mcp,
{
int ret;
u16 total_len;
+ int retries = 0;
mcp->txbuf[0] = type;
if (msg) {
@@ -301,20 +322,31 @@ static int mcp_i2c_smbus_read(struct mcp2221 *mcp,
mcp->rxbuf_idx = 0;
do {
+ /* Wait for the data to be read by the device */
+ usleep_range(980, 1000);
+
memset(mcp->txbuf, 0, 4);
mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
- if (ret)
- return ret;
-
- ret = mcp_chk_last_cmd_status(mcp);
- if (ret)
- return ret;
-
- usleep_range(980, 1000);
+ if (ret) {
+ if (retries < 5) {
+ /* The data wasn't ready to read.
+ * Wait a bit longer and try again.
+ */
+ usleep_range(90, 100);
+ retries++;
+ } else {
+ return ret;
+ }
+ } else {
+ retries = 0;
+ }
} while (mcp->rxbuf_idx < total_len);
+ usleep_range(980, 1000);
+ ret = mcp_chk_last_cmd_status_free_bus(mcp);
+
return ret;
}
@@ -328,11 +360,6 @@ static int mcp_i2c_xfer(struct i2c_adapter *adapter,
mutex_lock(&mcp->lock);
- /* Setting speed before every transaction is required for mcp2221 */
- ret = mcp_set_i2c_speed(mcp);
- if (ret)
- goto exit;
-
if (num == 1) {
if (msgs->flags & I2C_M_RD) {
ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA,
@@ -417,9 +444,7 @@ static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr,
if (last_status) {
usleep_range(980, 1000);
- ret = mcp_chk_last_cmd_status(mcp);
- if (ret)
- return ret;
+ ret = mcp_chk_last_cmd_status_free_bus(mcp);
}
return ret;
@@ -437,10 +462,6 @@ static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
mutex_lock(&mcp->lock);
- ret = mcp_set_i2c_speed(mcp);
- if (ret)
- goto exit;
-
switch (size) {
case I2C_SMBUS_QUICK:
@@ -791,7 +812,8 @@ static int mcp2221_raw_event(struct hid_device *hdev,
mcp->status = -EIO;
break;
}
- if (data[2] == MCP2221_I2C_READ_COMPL) {
+ if (data[2] == MCP2221_I2C_READ_COMPL ||
+ data[2] == MCP2221_I2C_READ_PARTIAL) {
buf = mcp->rxbuf;
memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]);
mcp->rxbuf_idx = mcp->rxbuf_idx + data[3];
@@ -1150,12 +1172,18 @@ static int mcp2221_probe(struct hid_device *hdev,
if (i2c_clk_freq < 50)
i2c_clk_freq = 50;
mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3;
+ ret = mcp_set_i2c_speed(mcp);
+ if (ret) {
+ hid_err(hdev, "can't set i2c speed: %d\n", ret);
+ return ret;
+ }
mcp->adapter.owner = THIS_MODULE;
mcp->adapter.class = I2C_CLASS_HWMON;
mcp->adapter.algo = &mcp_i2c_algo;
mcp->adapter.retries = 1;
mcp->adapter.dev.parent = &hdev->dev;
+ ACPI_COMPANION_SET(&mcp->adapter.dev, ACPI_COMPANION(hdev->dev.parent));
snprintf(mcp->adapter.name, sizeof(mcp->adapter.name),
"MCP2221 usb-i2c bridge");