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authorEddie James <eajames@linux.vnet.ibm.com>2018-07-17 10:31:05 -0500
committerWolfram Sang <wsa@the-dreams.de>2018-07-21 00:07:09 +0200
commit720d5ce9309d5503b2c29b621f5490e961f5953c (patch)
tree5ef5882d3d83fcafd819f24a86453a1afb91ca04 /drivers/i2c/busses
parentf4cdc319cff88eb83564a5466c15af8128dd8284 (diff)
downloadlinux-stericsson-720d5ce9309d5503b2c29b621f5490e961f5953c.tar.gz
i2c: fsi: Add bus recovery
Bus recovery should reset the bus with the standard i2c recovery procedure. Populate the necessary fields so that the standard procedure can perform the reset. Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com> Tested-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses')
-rw-r--r--drivers/i2c/busses/i2c-fsi.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c
index 27d74a944c72..1e2be2219a60 100644
--- a/drivers/i2c/busses/i2c-fsi.c
+++ b/drivers/i2c/busses/i2c-fsi.c
@@ -326,6 +326,115 @@ static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg,
return 0;
}
+static int fsi_i2c_get_scl(struct i2c_adapter *adap)
+{
+ u32 stat = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+
+ return !!(stat & I2C_STAT_SCL_IN);
+}
+
+static void fsi_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ u32 dummy = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ if (val)
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);
+ else
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);
+}
+
+static int fsi_i2c_get_sda(struct i2c_adapter *adap)
+{
+ u32 stat = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+
+ return !!(stat & I2C_STAT_SDA_IN);
+}
+
+static void fsi_i2c_set_sda(struct i2c_adapter *adap, int val)
+{
+ u32 dummy = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ if (val)
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy);
+ else
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy);
+}
+
+static void fsi_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ int rc;
+ u32 mode;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return;
+
+ mode |= I2C_MODE_DIAG;
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+}
+
+static void fsi_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ int rc;
+ u32 mode;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return;
+
+ mode &= ~I2C_MODE_DIAG;
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+}
+
+static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c,
+ struct fsi_i2c_port *port)
+{
+ int rc;
+ u32 stat, dummy = 0;
+
+ /* force bus reset, ignore errors */
+ i2c_recover_bus(&port->adapter);
+
+ /* reset errors */
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy);
+ if (rc)
+ return rc;
+
+ /* wait for command complete */
+ usleep_range(I2C_RESET_SLEEP_MIN_US, I2C_RESET_SLEEP_MAX_US);
+
+ 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 */
+ return fsi_i2c_dev_init(i2c);
+}
+
static int fsi_i2c_reset_engine(struct fsi_i2c_master *i2c, u16 port)
{
int rc;
@@ -368,6 +477,7 @@ static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status)
int rc;
unsigned long start;
u32 cmd = I2C_CMD_WITH_STOP;
+ u32 stat;
struct fsi_i2c_master *i2c = port->master;
struct fsi_device *fsi = i2c->fsi;
@@ -375,6 +485,17 @@ static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status)
if (rc)
return rc;
+ rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &stat);
+ if (rc)
+ return rc;
+
+ /* if sda is low, peform full bus reset */
+ if (!(stat & I2C_STAT_SDA_IN)) {
+ rc = fsi_i2c_reset_bus(i2c, 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;
@@ -522,6 +643,16 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
}
+static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = {
+ .recover_bus = i2c_generic_scl_recovery,
+ .get_scl = fsi_i2c_get_scl,
+ .set_scl = fsi_i2c_set_scl,
+ .get_sda = fsi_i2c_get_sda,
+ .set_sda = fsi_i2c_set_sda,
+ .prepare_recovery = fsi_i2c_prepare_recovery,
+ .unprepare_recovery = fsi_i2c_unprepare_recovery,
+};
+
static const struct i2c_algorithm fsi_i2c_algorithm = {
.master_xfer = fsi_i2c_xfer,
.functionality = fsi_i2c_functionality,
@@ -564,6 +695,7 @@ static int fsi_i2c_probe(struct device *dev)
port->adapter.dev.of_node = np;
port->adapter.dev.parent = dev;
port->adapter.algo = &fsi_i2c_algorithm;
+ port->adapter.bus_recovery_info = &fsi_i2c_bus_recovery_info;
port->adapter.algo_data = port;
snprintf(port->adapter.name, sizeof(port->adapter.name),