Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-17 22:05:08 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

i2c: cadence: Split cdns_i2c_master_xfer for Atomic Mode

Browse Source 
The cdns_i2c_master_xfer function has been refactored to separate
the common code. This change facilitates better support for atomic
mode operations by isolating the shared logic.

Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
This commit is contained in:
Manikanta Guntupalli 2024-09-11 16:08:51 +05:30 committed by Andi Shyti
parent ae8ec9dd19
commit ed866f4161
1 changed files with 77 additions and 71 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

148
drivers/i2c/busses/i2c-cadence.c
View File

@ -866,6 +866,78 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
return 0;
}
static int cdns_i2c_master_common_xfer(struct i2c_adapter *adap,
struct i2c_msg *msgs,
int num)
{
int ret, count;
u32 reg;
struct cdns_i2c *id = adap->algo_data;
bool hold_quirk;
/* Check if the bus is free */
ret = readl_relaxed_poll_timeout(id->membase + CDNS_I2C_SR_OFFSET,
reg,
!(reg & CDNS_I2C_SR_BA),
CDNS_I2C_POLL_US, CDNS_I2C_TIMEOUT_US);
if (ret) {
ret = -EAGAIN;
if (id->adap.bus_recovery_info)
i2c_recover_bus(adap);
return ret;
}
hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);
/*
* Set the flag to one when multiple messages are to be
* processed with a repeated start.
*/
if (num > 1) {
/*
* This controller does not give completion interrupt after a
* master receive message if HOLD bit is set (repeated start),
* resulting in SW timeout. Hence, if a receive message is
* followed by any other message, an error is returned
* indicating that this sequence is not supported.
*/
for (count = 0; (count < num - 1 && hold_quirk); count++) {
if (msgs[count].flags & I2C_M_RD) {
dev_warn(adap->dev.parent,
"Can't do repeated start after a receive message\n");
return -EOPNOTSUPP;
}
}
id->bus_hold_flag = 1;
reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
reg |= CDNS_I2C_CR_HOLD;
cdns_i2c_writereg(reg, CDNS_I2C_CR_OFFSET);
} else {
id->bus_hold_flag = 0;
}
/* Process the msg one by one */
for (count = 0; count < num; count++, msgs++) {
if (count == (num - 1))
id->bus_hold_flag = 0;
ret = cdns_i2c_process_msg(id, msgs, adap);
if (ret)
return ret;
/* Report the other error interrupts to application */
if (id->err_status) {
cdns_i2c_master_reset(adap);
if (id->err_status & CDNS_I2C_IXR_NACK)
return -ENXIO;
return -EIO;
}
}
return 0;
}
/**
* cdns_i2c_master_xfer - The main i2c transfer function
* @adap: pointer to the i2c adapter driver instance
@ -879,10 +951,8 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num)
{
int ret, count;
u32 reg;
int ret;
struct cdns_i2c *id = adap->algo_data;
bool hold_quirk;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
bool change_role = false;
#endif
@ -907,75 +977,11 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
}
#endif
/* Check if the bus is free */
ret = readl_relaxed_poll_timeout(id->membase + CDNS_I2C_SR_OFFSET,
reg,
!(reg & CDNS_I2C_SR_BA),
CDNS_I2C_POLL_US, CDNS_I2C_TIMEOUT_US);
if (ret) {
ret = -EAGAIN;
if (id->adap.bus_recovery_info)
i2c_recover_bus(adap);
goto out;
}
hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);
/*
* Set the flag to one when multiple messages are to be
* processed with a repeated start.
*/
if (num > 1) {
/*
* This controller does not give completion interrupt after a
* master receive message if HOLD bit is set (repeated start),
* resulting in SW timeout. Hence, if a receive message is
* followed by any other message, an error is returned
* indicating that this sequence is not supported.
*/
for (count = 0; (count < num - 1 && hold_quirk); count++) {
if (msgs[count].flags & I2C_M_RD) {
dev_warn(adap->dev.parent,
"Can't do repeated start after a receive message\n");
ret = -EOPNOTSUPP;
goto out;
}
}
id->bus_hold_flag = 1;
reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
reg |= CDNS_I2C_CR_HOLD;
cdns_i2c_writereg(reg, CDNS_I2C_CR_OFFSET);
} else {
id->bus_hold_flag = 0;
}
/* Process the msg one by one */
for (count = 0; count < num; count++, msgs++) {
if (count == (num - 1))
id->bus_hold_flag = 0;
ret = cdns_i2c_process_msg(id, msgs, adap);
if (ret)
goto out;
/* Report the other error interrupts to application */
if (id->err_status) {
cdns_i2c_master_reset(adap);
if (id->err_status & CDNS_I2C_IXR_NACK) {
ret = -ENXIO;
goto out;
}
ret = -EIO;
goto out;
}
}
ret = num;
out:
ret = cdns_i2c_master_common_xfer(adap, msgs, num);
if (!ret)
ret = num;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
out:
/* Switch i2c mode to slave */
if (change_role)
cdns_i2c_set_mode(CDNS_I2C_MODE_SLAVE, id);