| From patchwork Wed May 10 15:52:41 2017 |
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| Subject: [linux, dev-4.10, v2, |
| 5/6] drivers: i2c: Add bus recovery for FSI algorithm |
| From: eajames@linux.vnet.ibm.com |
| X-Patchwork-Id: 760701 |
| Message-Id: <1494431562-25101-6-git-send-email-eajames@linux.vnet.ibm.com> |
| To: openbmc@lists.ozlabs.org |
| Cc: "Edward A. James" <eajames@us.ibm.com>, cbostic@linux.vnet.ibm.com |
| Date: Wed, 10 May 2017 10:52:41 -0500 |
| |
| From: "Edward A. James" <eajames@us.ibm.com> |
| |
| Bus recovery should reset the engine and force block the bus 9 times |
| to recover most situations. |
| |
| Signed-off-by: Edward A. James <eajames@us.ibm.com> |
| --- |
| 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 d757aee..4689479 100644 |
| --- a/drivers/i2c/busses/i2c-fsi.c |
| +++ b/drivers/i2c/busses/i2c-fsi.c |
| @@ -467,6 +467,80 @@ 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, |
| @@ -514,6 +588,8 @@ 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) + |