From: Eddie James <eajames@linux.vnet.ibm.com>
To: openbmc@lists.ozlabs.org
Cc: joel@jms.id.au, andrew@aj.id.au, "Edward A. James" <eajames@us.ibm.com>
Subject: [PATCH linux dev-4.10] drivers: i2c: fsi: Add proper abort method
Date: Thu, 12 Oct 2017 15:42:24 -0500 [thread overview]
Message-ID: <1507840944-421-1-git-send-email-eajames@linux.vnet.ibm.com> (raw)
From: "Edward A. James" <eajames@us.ibm.com>
Driver wasn't cleaning up on timeout or in an error situation properly.
Need to do a full reset if we fail in order to re-stablish a good state
of the engine.
Signed-off-by: Edward A. James <eajames@us.ibm.com>
---
drivers/i2c/busses/i2c-fsi.c | 259 +++++++++++++++++++++++++++++++------------
1 file changed, 191 insertions(+), 68 deletions(-)
diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c
index 1af9c01..6c582d8 100644
--- a/drivers/i2c/busses/i2c-fsi.c
+++ b/drivers/i2c/busses/i2c-fsi.c
@@ -133,6 +133,11 @@
#define I2C_ESTAT_SELF_BUSY 0x00000040
#define I2C_ESTAT_VERSION 0x0000001f
+#define I2C_PORT_BUSY_RESET 0x80000000
+
+#define I2C_LOCAL_WAIT_TIMEOUT 2 /* jiffies */
+#define I2C_ABORT_TIMEOUT msecs_to_jiffies(100)
+
struct fsi_i2c_master {
struct fsi_device *fsi;
u8 fifo_size;
@@ -351,22 +356,185 @@ static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg,
return rc;
}
+static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c)
+{
+ int i, rc;
+ u32 mode, dummy = 0;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ mode |= I2C_MODE_DIAG;
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < 9; ++i) {
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);
+ if (rc)
+ return rc;
+ }
+
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy);
+ if (rc)
+ return rc;
+
+ mode &= ~I2C_MODE_DIAG;
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+
+ return rc;
+}
+
+static int fsi_i2c_reset(struct fsi_i2c_master *i2c, u16 port)
+{
+ int rc;
+ u32 mode, stat, dummy = 0;
+
+ /* reset engine */
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);
+ if (rc)
+ return rc;
+
+ /* re-init engine */
+ rc = fsi_i2c_dev_init(i2c);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ /* set port; default after reset is 0 */
+ if (port) {
+ mode = SETFIELD(I2C_MODE_PORT, mode, port);
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+ }
+
+ /* reset busy register; hw workaround */
+ dummy = I2C_PORT_BUSY_RESET;
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_PORT_BUSY, &dummy);
+ if (rc)
+ return rc;
+
+ /* force bus reset */
+ rc = fsi_i2c_reset_bus(i2c);
+ if (rc)
+ return rc;
+
+ /* reset errors */
+ dummy = 0;
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy);
+ if (rc)
+ return rc;
+
+ /* wait for command complete */
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(I2C_LOCAL_WAIT_TIMEOUT);
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+ if (rc)
+ return rc;
+
+ if (stat & I2C_STAT_CMD_COMP)
+ return 0;
+
+ /* failed to get command complete; reset engine again */
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);
+ if (rc)
+ return rc;
+
+ /* re-init engine again */
+ rc = fsi_i2c_dev_init(i2c);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
+static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status)
+{
+ int rc;
+ unsigned long start;
+ u32 cmd = I2C_CMD_WITH_STOP;
+ struct fsi_device *fsi = port->master->fsi;
+
+ rc = fsi_i2c_reset(port->master, port->port);
+ if (rc)
+ return rc;
+
+ /* skip final stop command for these errors */
+ if (status & (I2C_STAT_PARITY | I2C_STAT_LOST_ARB | I2C_STAT_STOP_ERR))
+ return 0;
+
+ rc = fsi_i2c_write_reg(fsi, I2C_FSI_CMD, &cmd);
+ if (rc)
+ return rc;
+
+ start = jiffies;
+
+ do {
+ rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &status);
+ if (rc)
+ return rc;
+
+ if (status & I2C_STAT_CMD_COMP)
+ return 0;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (schedule_timeout(I2C_LOCAL_WAIT_TIMEOUT) > 0)
+ return -EINTR;
+
+ } while (time_after(start + I2C_ABORT_TIMEOUT, jiffies));
+
+ return -ETIME;
+}
+
static int fsi_i2c_handle_status(struct fsi_i2c_port *port,
struct i2c_msg *msg, u32 status)
{
int rc;
u8 fifo_count;
- struct fsi_i2c_master *i2c = port->master;
- u32 dummy = 0;
if (status & I2C_STAT_ERR) {
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy);
+ rc = fsi_i2c_abort(port, status);
if (rc)
return rc;
+ if (status & I2C_STAT_INV_CMD)
+ return -EINVAL;
+
+ if (status & (I2C_STAT_PARITY | I2C_STAT_BE_OVERRUN |
+ I2C_STAT_BE_ACCESS))
+ return -EPROTO;
+
if (status & I2C_STAT_NACK)
return -EFAULT;
+ if (status & I2C_STAT_LOST_ARB)
+ return -ECANCELED;
+
+ if (status & I2C_STAT_STOP_ERR)
+ return -EBADMSG;
+
return -EIO;
}
@@ -396,9 +564,9 @@ static int fsi_i2c_handle_status(struct fsi_i2c_port *port,
static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg,
unsigned long timeout)
{
- const unsigned long local_timeout = 2; /* jiffies */
u32 status = 0;
- int rc;
+ int rc, rc_abort;
+ unsigned long start = jiffies;
do {
rc = fsi_i2c_read_reg(port->master->fsi, I2C_FSI_STAT,
@@ -419,13 +587,21 @@ static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg,
continue;
}
- set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(local_timeout);
- timeout = (timeout < local_timeout) ? 0 :
- timeout - local_timeout;
- } while (timeout);
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (schedule_timeout(I2C_LOCAL_WAIT_TIMEOUT) > 0) {
+ rc = -EINTR;
+ goto abort;
+ }
+ } while (time_after(start + timeout, jiffies));
- return -ETIME;
+ rc = -ETIME;
+
+abort:
+ rc_abort = fsi_i2c_abort(port, status);
+ if (rc_abort)
+ return rc_abort;
+
+ return rc;
}
static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
@@ -469,72 +645,19 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
| I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
}
-static int fsi_i2c_low_level_recover_bus(struct fsi_i2c_master *i2c)
-{
- int i, rc;
- u32 mode, dummy = 0;
-
- rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
- if (rc)
- return rc;
-
- mode |= I2C_MODE_DIAG;
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
- if (rc)
- return rc;
-
- for (i = 0; i < 9; ++i) {
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);
- if (rc)
- return rc;
-
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);
- if (rc)
- return rc;
- }
-
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);
- if (rc)
- return rc;
-
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy);
- if (rc)
- return rc;
-
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);
- if (rc)
- return rc;
-
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy);
- if (rc)
- return rc;
-
- mode &= ~I2C_MODE_DIAG;
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
-
- return rc;
-}
-
static int fsi_i2c_recover_bus(struct i2c_adapter *adap)
{
int rc;
- u32 dummy = 0;
struct fsi_i2c_port *port = adap->algo_data;
- struct fsi_i2c_master *i2c = port->master;
+ struct fsi_i2c_master *master = port->master;
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);
+ rc = fsi_i2c_lock_master(master, adap->timeout);
if (rc)
return rc;
- rc = fsi_i2c_dev_init(i2c);
- if (rc)
- return rc;
+ rc = fsi_i2c_reset(master, port->port);
- rc = fsi_i2c_low_level_recover_bus(i2c);
- if (rc)
- return rc;
-
- rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy);
+ fsi_i2c_unlock_master(master);
return rc;
}
--
1.8.3.1
next reply other threads:[~2017-10-12 20:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-12 20:42 Eddie James [this message]
2017-10-13 6:18 ` [PATCH linux dev-4.10] drivers: i2c: fsi: Add proper abort method Andrew Jeffery
2017-10-13 15:20 ` Eddie James
2017-10-20 4:45 ` Andrew Jeffery
2017-10-20 14:07 ` Eddie James
2017-10-20 5:15 ` Andrew Jeffery
2017-10-20 14:00 ` Eddie James
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