From: "Edward A. James" <eajames@xxxxxxxxxx> Bus recovery should reset the engine and force clock the bus 9 times to recover most situations. Signed-off-by: Edward A. James <eajames@xxxxxxxxxx> --- drivers/i2c/busses/i2c-fsi.c | 76 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 41193be..690589e 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -469,6 +469,80 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap) return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_10BIT_ADDR; } +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; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy); + if (rc) + return rc; + + rc = fsi_i2c_dev_init(i2c); + if (rc) + return rc; + + rc = fsi_i2c_low_level_recover_bus(i2c); + if (rc) + return rc; + + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy); + + return rc; +} + +static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = { + .recover_bus = fsi_i2c_recover_bus, +}; + static const struct i2c_algorithm fsi_i2c_algorithm = { .master_xfer = fsi_i2c_xfer, .functionality = fsi_i2c_functionality, @@ -516,6 +590,8 @@ static int fsi_i2c_probe(struct device *dev) port->adapter.owner = THIS_MODULE; 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; /* number ports uniquely */ port->adapter.nr = (i2c->idx * I2C_MASTER_NR_OFFSET) + -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html