From: Tang Yuantian <B29983@xxxxxxxxxxxxx>
Add support for SMBUS_READ_BLOCK_DATA to the i2c-mpc bus driver.
Signed-off-by: Tang Yuantian <Yuantian.Tang@xxxxxxxxxxxxx>
Cc: Ben Dooks <ben-linux@xxxxxxxxx>
Cc: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
---
Add Cc and resend this patch
tested on p1022ds
v2 vs v1:
-remove signature
drivers/i2c/busses/i2c-mpc.c | 63 ++++++++++++++++++++++++++++++++---------
1 files changed, 49 insertions(+), 14 deletions(-)
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 107397a..bba9a07 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -454,7 +454,7 @@ static int mpc_write(struct mpc_i2c *i2c, int target,
}
static int mpc_read(struct mpc_i2c *i2c, int target,
- u8 *data, int length, int restart)
+ u8 *data, int length, int restart, bool recv_len)
{
unsigned timeout = i2c->adap.timeout;
int i, result;
@@ -470,7 +470,7 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
return result;
if (length) {
- if (length == 1)
+ if (length == 1 && !recv_len)
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
else
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
@@ -479,17 +479,46 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
}
for (i = 0; i < length; i++) {
+ u8 byte;
+
result = i2c_wait(i2c, timeout, 0);
if (result < 0)
return result;
- /* Generate txack on next to last byte */
- if (i == length - 2)
- writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
- /* Do not generate stop on last byte */
- if (i == length - 1)
- writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
- data[i] = readb(i2c->base + MPC_I2C_DR);
+ /*
+ * For block reads, we have to know the total length (1st byte)
+ * before we can determine if we are done.
+ */
+ if (i || !recv_len) {
+ /* Generate txack on next to last byte */
+ if (i == length - 2)
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+ | CCR_TXAK);
+ /* Do not generate stop on last byte */
+ if (i == length - 1)
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+ | CCR_MTX);
+ }
+
+ byte = readb(i2c->base + MPC_I2C_DR);
+
+ /*
+ * Adjust length if first received byte is length.
+ * The length is 1 length byte plus actually data length
+ */
+ if (i == 0 && recv_len) {
+ if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
+ return -EPROTO;
+ length += byte;
+ /*
+ * For block reads, generate txack here if data length
+ * is 1 byte (total length is 2 bytes).
+ */
+ if (length == 2)
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+ | CCR_TXAK);
+ }
+ data[i] = byte;
}
return length;
@@ -532,12 +561,17 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
"Doing %s %d bytes to 0x%02x - %d of %d messages\n",
pmsg->flags & I2C_M_RD ? "read" : "write",
pmsg->len, pmsg->addr, i + 1, num);
- if (pmsg->flags & I2C_M_RD)
- ret =
- mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
- else
+ if (pmsg->flags & I2C_M_RD) {
+ bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
+
+ ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
+ recv_len);
+ if (recv_len && ret > 0)
+ pmsg->len = ret;
+ } else {
ret =
mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+ }
}
mpc_i2c_stop(i2c);
return (ret < 0) ? ret : num;
@@ -545,7 +579,8 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
static u32 mpc_functionality(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+ | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
}
static const struct i2c_algorithm mpc_algo = {
--
1.6.4
--
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