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i2c: mpc: Add support for SMBUS_READ_BLOCK_DATA

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Add support for SMBUS_READ_BLOCK_DATA to the i2c-mpc bus driver.

Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Tang Yuantian 2012-02-23 17:42:45 +08:00 committed by Wolfram Sang
parent 237ab4062d
commit 3f0e1e4bb6
1 changed files with 49 additions and 14 deletions
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63
drivers/i2c/busses/i2c-mpc.c
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@ -454,7 +454,7 @@ static int mpc_write(struct mpc_i2c *i2c, int target,
} }
static int mpc_read(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; unsigned timeout = i2c->adap.timeout;
int i, result; int i, result;
@ -470,7 +470,7 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
return result; return result;
if (length) { if (length) {
if (length == 1) if (length == 1 && !recv_len)
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK); writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
else else
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA); 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++) { for (i = 0; i < length; i++) {
u8 byte;
result = i2c_wait(i2c, timeout, 0); result = i2c_wait(i2c, timeout, 0);
if (result < 0) if (result < 0)
return result; return result;
/* Generate txack on next to last byte */ /*
if (i == length - 2) * For block reads, we have to know the total length (1st byte)
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK); * before we can determine if we are done.
/* Do not generate stop on last byte */ */
if (i == length - 1) if (i || !recv_len) {
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX); /* Generate txack on next to last byte */
data[i] = readb(i2c->base + MPC_I2C_DR); 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; 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", "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
pmsg->flags & I2C_M_RD ? "read" : "write", pmsg->flags & I2C_M_RD ? "read" : "write",
pmsg->len, pmsg->addr, i + 1, num); pmsg->len, pmsg->addr, i + 1, num);
if (pmsg->flags & I2C_M_RD) if (pmsg->flags & I2C_M_RD) {
ret = bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
else ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
recv_len);
if (recv_len && ret > 0)
pmsg->len = ret;
} else {
ret = ret =
mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i); mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
}
} }
mpc_i2c_stop(i2c); mpc_i2c_stop(i2c);
return (ret < 0) ? ret : num; 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) 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 = { static const struct i2c_algorithm mpc_algo = {