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James" Subject: [PATCH linux dev-4.10] drivers: i2c: fsi: Add proper abort method Date: Thu, 12 Oct 2017 15:42:24 -0500 X-Mailer: git-send-email 1.8.3.1 X-TM-AS-GCONF: 00 x-cbid: 17101220-0008-0000-0000-000008B478B9 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007886; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000236; SDB=6.00930223; UDB=6.00468256; IPR=6.00710489; BA=6.00005635; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017512; XFM=3.00000015; UTC=2017-10-12 20:42:28 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17101220-0009-0000-0000-000044568828 Message-Id: <1507840944-421-1-git-send-email-eajames@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-10-12_10:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710120293 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Oct 2017 20:42:36 -0000 From: "Edward A. James" 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 --- 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