Edward A. James | 7bd8637 | 2017-05-15 12:28:44 -0500 | [diff] [blame] | 1 | From patchwork Wed May 10 15:52:41 2017 |
| 2 | Content-Type: text/plain; charset="utf-8" |
| 3 | MIME-Version: 1.0 |
| 4 | Content-Transfer-Encoding: 7bit |
| 5 | Subject: [linux, dev-4.10, v2, |
| 6 | 5/6] drivers: i2c: Add bus recovery for FSI algorithm |
| 7 | From: eajames@linux.vnet.ibm.com |
| 8 | X-Patchwork-Id: 760701 |
| 9 | Message-Id: <1494431562-25101-6-git-send-email-eajames@linux.vnet.ibm.com> |
| 10 | To: openbmc@lists.ozlabs.org |
| 11 | Cc: "Edward A. James" <eajames@us.ibm.com>, cbostic@linux.vnet.ibm.com |
| 12 | Date: Wed, 10 May 2017 10:52:41 -0500 |
| 13 | |
| 14 | From: "Edward A. James" <eajames@us.ibm.com> |
| 15 | |
| 16 | Bus recovery should reset the engine and force block the bus 9 times |
| 17 | to recover most situations. |
| 18 | |
| 19 | Signed-off-by: Edward A. James <eajames@us.ibm.com> |
| 20 | --- |
| 21 | drivers/i2c/busses/i2c-fsi.c | 76 ++++++++++++++++++++++++++++++++++++++++++++ |
| 22 | 1 file changed, 76 insertions(+) |
| 23 | |
| 24 | diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c |
| 25 | index d757aee..4689479 100644 |
| 26 | --- a/drivers/i2c/busses/i2c-fsi.c |
| 27 | +++ b/drivers/i2c/busses/i2c-fsi.c |
| 28 | @@ -467,6 +467,80 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap) |
| 29 | return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_10BIT_ADDR; |
| 30 | } |
| 31 | |
| 32 | +static int fsi_i2c_low_level_recover_bus(struct fsi_i2c_master *i2c) |
| 33 | +{ |
| 34 | + int i, rc; |
| 35 | + u32 mode, dummy = 0; |
| 36 | + |
| 37 | + rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 38 | + if (rc) |
| 39 | + return rc; |
| 40 | + |
| 41 | + mode |= I2C_MODE_DIAG; |
| 42 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 43 | + if (rc) |
| 44 | + return rc; |
| 45 | + |
| 46 | + for (i = 0; i < 9; ++i) { |
| 47 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy); |
| 48 | + if (rc) |
| 49 | + return rc; |
| 50 | + |
| 51 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy); |
| 52 | + if (rc) |
| 53 | + return rc; |
| 54 | + } |
| 55 | + |
| 56 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy); |
| 57 | + if (rc) |
| 58 | + return rc; |
| 59 | + |
| 60 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy); |
| 61 | + if (rc) |
| 62 | + return rc; |
| 63 | + |
| 64 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy); |
| 65 | + if (rc) |
| 66 | + return rc; |
| 67 | + |
| 68 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy); |
| 69 | + if (rc) |
| 70 | + return rc; |
| 71 | + |
| 72 | + mode &= ~I2C_MODE_DIAG; |
| 73 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); |
| 74 | + |
| 75 | + return rc; |
| 76 | +} |
| 77 | + |
| 78 | +static int fsi_i2c_recover_bus(struct i2c_adapter *adap) |
| 79 | +{ |
| 80 | + int rc; |
| 81 | + u32 dummy = 0; |
| 82 | + struct fsi_i2c_port *port = adap->algo_data; |
| 83 | + struct fsi_i2c_master *i2c = port->master; |
| 84 | + |
| 85 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy); |
| 86 | + if (rc) |
| 87 | + return rc; |
| 88 | + |
| 89 | + rc = fsi_i2c_dev_init(i2c); |
| 90 | + if (rc) |
| 91 | + return rc; |
| 92 | + |
| 93 | + rc = fsi_i2c_low_level_recover_bus(i2c); |
| 94 | + if (rc) |
| 95 | + return rc; |
| 96 | + |
| 97 | + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy); |
| 98 | + |
| 99 | + return rc; |
| 100 | +} |
| 101 | + |
| 102 | +static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = { |
| 103 | + .recover_bus = fsi_i2c_recover_bus, |
| 104 | +}; |
| 105 | + |
| 106 | static const struct i2c_algorithm fsi_i2c_algorithm = { |
| 107 | .master_xfer = fsi_i2c_xfer, |
| 108 | .functionality = fsi_i2c_functionality, |
| 109 | @@ -514,6 +588,8 @@ static int fsi_i2c_probe(struct device *dev) |
| 110 | port->adapter.owner = THIS_MODULE; |
| 111 | port->adapter.dev.parent = dev; |
| 112 | port->adapter.algo = &fsi_i2c_algorithm; |
| 113 | + port->adapter.bus_recovery_info = |
| 114 | + &fsi_i2c_bus_recovery_info; |
| 115 | port->adapter.algo_data = port; |
| 116 | /* number ports uniquely */ |
| 117 | port->adapter.nr = (i2c->idx * I2C_MASTER_NR_OFFSET) + |