/* Copyright 2013-2014 IBM Corp. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or * implied. * See the License for the specific language governing permissions and * limitations under the License. */ #undef DEBUG #include #include #include #include #include #include #include #include #include #include #include #include DEFINE_LOG_ENTRY(OPAL_RC_I2C_INIT, OPAL_PLATFORM_ERR_EVT, OPAL_I2C, OPAL_IO_SUBSYSTEM, OPAL_PREDICTIVE_ERR_DEGRADED_PERF, OPAL_NA); DEFINE_LOG_ENTRY(OPAL_RC_I2C_START_REQ, OPAL_INPUT_OUTPUT_ERR_EVT, OPAL_I2C, OPAL_IO_SUBSYSTEM, OPAL_INFO, OPAL_NA); DEFINE_LOG_ENTRY(OPAL_RC_I2C_TIMEOUT, OPAL_INPUT_OUTPUT_ERR_EVT, OPAL_I2C, OPAL_IO_SUBSYSTEM, OPAL_INFO, OPAL_NA); DEFINE_LOG_ENTRY(OPAL_RC_I2C_TRANSFER, OPAL_INPUT_OUTPUT_ERR_EVT, OPAL_I2C, OPAL_IO_SUBSYSTEM, OPAL_INFO, OPAL_NA); DEFINE_LOG_ENTRY(OPAL_RC_I2C_RESET, OPAL_INPUT_OUTPUT_ERR_EVT, OPAL_I2C, OPAL_IO_SUBSYSTEM, OPAL_INFO, OPAL_NA); #ifdef DEBUG #define DBG(fmt...) prlog(PR_ERR, "I2C: " fmt) #define I2C_TIMEOUT_IRQ_MS 100 /* 100ms/byte timeout */ #define I2C_TIMEOUT_POLL_MS 4000 /* 4s/byte timeout */ #else #define DBG(fmt...) prlog(PR_TRACE, "I2C: " fmt) #define I2C_TIMEOUT_IRQ_MS 1 /* 1ms/byte timeout */ #define I2C_TIMEOUT_POLL_MS 4000 /* 4s/byte timeout */ #endif /* How long to keep the sensor cache disabled after an access * in milliseconds */ #define SENSOR_CACHE_EN_DELAY 10 #define USEC_PER_SEC 1000000 #define USEC_PER_MSEC 1000 #define I2C_RESET_DELAY_MS 5 /* 5 msecs */ #define I2C_FIFO_HI_LVL 4 #define I2C_FIFO_LO_LVL 4 /* * I2C registers set. * Below is the offset of registers from base which is stored in the * 'struct p8_i2c_master' */ /* I2C FIFO register */ #define I2C_FIFO_REG 0x4 #define I2C_FIFO PPC_BITMASK(0, 7) /* I2C command register */ #define I2C_CMD_REG 0x5 #define I2C_CMD_WITH_START PPC_BIT(0) #define I2C_CMD_WITH_ADDR PPC_BIT(1) #define I2C_CMD_READ_CONT PPC_BIT(2) #define I2C_CMD_WITH_STOP PPC_BIT(3) #define I2C_CMD_DEV_ADDR PPC_BITMASK(8, 14) #define I2C_CMD_READ_NOT_WRITE PPC_BIT(15) #define I2C_CMD_LEN_BYTES PPC_BITMASK(16, 31) #define I2C_MAX_TFR_LEN 0xfff0ull /* I2C mode register */ #define I2C_MODE_REG 0x6 #define I2C_MODE_BIT_RATE_DIV PPC_BITMASK(0, 15) #define I2C_MODE_PORT_NUM PPC_BITMASK(16, 21) #define I2C_MODE_ENHANCED PPC_BIT(28) #define I2C_MODE_DIAGNOSTIC PPC_BIT(29) #define I2C_MODE_PACING_ALLOW PPC_BIT(30) #define I2C_MODE_WRAP PPC_BIT(31) /* I2C watermark register */ #define I2C_WATERMARK_REG 0x7 #define I2C_WATERMARK_HIGH PPC_BITMASK(16, 19) #define I2C_WATERMARK_LOW PPC_BITMASK(24, 27) /* I2C interrupt mask, condition and interrupt registers */ #define I2C_INTR_MASK_REG 0x8 #define I2C_INTR_COND_REG 0x9 #define I2C_INTR_REG 0xa #define I2C_INTR_ALL PPC_BITMASK(16, 31) #define I2C_INTR_INVALID_CMD PPC_BIT(16) #define I2C_INTR_LBUS_PARITY_ERR PPC_BIT(17) #define I2C_INTR_BKEND_OVERRUN_ERR PPC_BIT(18) #define I2C_INTR_BKEND_ACCESS_ERR PPC_BIT(19) #define I2C_INTR_ARBT_LOST_ERR PPC_BIT(20) #define I2C_INTR_NACK_RCVD_ERR PPC_BIT(21) #define I2C_INTR_DATA_REQ PPC_BIT(22) #define I2C_INTR_CMD_COMP PPC_BIT(23) #define I2C_INTR_STOP_ERR PPC_BIT(24) #define I2C_INTR_I2C_BUSY PPC_BIT(25) #define I2C_INTR_NOT_I2C_BUSY PPC_BIT(26) #define I2C_INTR_SCL_EQ_1 PPC_BIT(28) #define I2C_INTR_SCL_EQ_0 PPC_BIT(29) #define I2C_INTR_SDA_EQ_1 PPC_BIT(30) #define I2C_INTR_SDA_EQ_0 PPC_BIT(31) /* I2C status register */ #define I2C_RESET_I2C_REG 0xb #define I2C_RESET_ERRORS 0xc #define I2C_STAT_REG 0xb #define I2C_STAT_INVALID_CMD PPC_BIT(0) #define I2C_STAT_LBUS_PARITY_ERR PPC_BIT(1) #define I2C_STAT_BKEND_OVERRUN_ERR PPC_BIT(2) #define I2C_STAT_BKEND_ACCESS_ERR PPC_BIT(3) #define I2C_STAT_ARBT_LOST_ERR PPC_BIT(4) #define I2C_STAT_NACK_RCVD_ERR PPC_BIT(5) #define I2C_STAT_DATA_REQ PPC_BIT(6) #define I2C_STAT_CMD_COMP PPC_BIT(7) #define I2C_STAT_STOP_ERR PPC_BIT(8) #define I2C_STAT_UPPER_THRS PPC_BITMASK(9, 15) #define I2C_STAT_ANY_I2C_INTR PPC_BIT(16) #define I2C_STAT_PORT_HISTORY_BUSY PPC_BIT(19) #define I2C_STAT_SCL_INPUT_LEVEL PPC_BIT(20) #define I2C_STAT_SDA_INPUT_LEVEL PPC_BIT(21) #define I2C_STAT_PORT_BUSY PPC_BIT(22) #define I2C_STAT_INTERFACE_BUSY PPC_BIT(23) #define I2C_STAT_FIFO_ENTRY_COUNT PPC_BITMASK(24, 31) #define I2C_STAT_ANY_ERR (I2C_STAT_INVALID_CMD | I2C_STAT_LBUS_PARITY_ERR | \ I2C_STAT_BKEND_OVERRUN_ERR | \ I2C_STAT_BKEND_ACCESS_ERR | I2C_STAT_ARBT_LOST_ERR | \ I2C_STAT_NACK_RCVD_ERR | I2C_STAT_STOP_ERR) /* Pseudo-status used for timeouts */ #define I2C_STAT_PSEUDO_TIMEOUT PPC_BIT(63) /* I2C extended status register */ #define I2C_EXTD_STAT_REG 0xc #define I2C_EXTD_STAT_FIFO_SIZE PPC_BITMASK(0, 7) #define I2C_EXTD_STAT_MSM_CURSTATE PPC_BITMASK(11, 15) #define I2C_EXTD_STAT_SCL_IN_SYNC PPC_BIT(16) #define I2C_EXTD_STAT_SDA_IN_SYNC PPC_BIT(17) #define I2C_EXTD_STAT_S_SCL PPC_BIT(18) #define I2C_EXTD_STAT_S_SDA PPC_BIT(19) #define I2C_EXTD_STAT_M_SCL PPC_BIT(20) #define I2C_EXTD_STAT_M_SDA PPC_BIT(21) #define I2C_EXTD_STAT_HIGH_WATER PPC_BIT(22) #define I2C_EXTD_STAT_LOW_WATER PPC_BIT(23) #define I2C_EXTD_STAT_I2C_BUSY PPC_BIT(24) #define I2C_EXTD_STAT_SELF_BUSY PPC_BIT(25) #define I2C_EXTD_STAT_I2C_VERSION PPC_BITMASK(27, 31) /* I2C residual front end/back end length */ #define I2C_RESIDUAL_LEN_REG 0xd #define I2C_RESIDUAL_FRONT_END PPC_BITMASK(0, 15) #define I2C_RESIDUAL_BACK_END PPC_BITMASK(16, 31) /* Port busy register */ #define I2C_PORT_BUYS_REG 0xe enum p8_i2c_master_type { I2C_POWER8, I2C_CENTAUR, MAX_I2C_TYPE, }; struct p8_i2c_master { struct lock lock; /* Lock to guard the members */ enum p8_i2c_master_type type; /* P8 vs. Centaur */ uint64_t poll_interval; /* Polling interval */ uint64_t byte_timeout; /* Timeout per byte */ uint64_t xscom_base; /* xscom base of i2cm */ uint32_t fifo_size; /* Maximum size of FIFO */ uint32_t chip_id; /* Chip the i2cm sits on */ uint32_t engine_id; /* Engine# on chip */ uint8_t obuf[4]; /* Offset buffer */ uint32_t bytes_sent; bool irq_ok; /* Interrupt working ? */ bool occ_cache_dis; /* I have disabled the cache */ enum request_state { state_idle, state_occache_dis, state_offset, state_data, state_error, state_recovery, } state; struct list_head req_list; /* Request queue head */ struct timer poller; struct timer timeout; struct timer recovery; struct timer sensor_cache; uint8_t recovery_pass; struct list_node link; }; struct p8_i2c_master_port { struct i2c_bus bus; /* Abstract bus struct for the client */ struct p8_i2c_master *master; uint32_t port_num; uint32_t bit_rate_div; /* Divisor to set bus speed*/ }; struct p8_i2c_request { struct i2c_request req; uint32_t port_num; uint64_t timeout; }; static void p8_i2c_print_debug_info(struct p8_i2c_master_port *port, struct i2c_request *req) { struct p8_i2c_master *master = port->master; uint64_t cmd, mode, stat, estat, intr; int rc; /* Print master and request structure bits */ log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Chip %08x Eng. %d Port %d--\n" " xscom_base=0x%016llx\tstate=%d\tbytes_sent=%d\n", master->chip_id, master->engine_id, port->port_num, master->xscom_base, master->state, master->bytes_sent); log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Request info--\n" " addr=0x%04x\toffset_bytes=%d\toffset=%d\tlen=%d\n", req->dev_addr, req->offset_bytes, req->offset, req->rw_len); /* Dump the current state of i2c registers */ rc = xscom_read(master->chip_id, master->xscom_base + I2C_CMD_REG, &cmd); if (rc) { prlog(PR_DEBUG, "I2C: Failed to read CMD_REG\n"); cmd = 0ull; } rc = xscom_read(master->chip_id, master->xscom_base + I2C_MODE_REG, &mode); if (rc) { prlog(PR_DEBUG, "I2C: Failed to read MODE_REG\n"); mode = 0ull; } rc = xscom_read(master->chip_id, master->xscom_base + I2C_STAT_REG, &stat); if (rc) { prlog(PR_DEBUG, "I2C: Failed to read STAT_REG\n"); stat = 0ull; } rc = xscom_read(master->chip_id, master->xscom_base + I2C_EXTD_STAT_REG, &estat); if (rc) { prlog(PR_DEBUG, "I2C: Failed to read EXTD_STAT_REG\n"); estat = 0ull; } rc = xscom_read(master->chip_id, master->xscom_base + I2C_INTR_MASK_REG, &intr); if (rc) { prlog(PR_DEBUG, "I2C: Failed to read INTR_MASK_REG\n"); intr = 0ull; } log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Register dump--\n" "cmd:0x%016llx\tmode:0x%016llx\tstat:0x%016llx\n" "estat:0x%016llx\tintr:0x%016llx\n", cmd, mode, stat, estat, intr); } static bool p8_i2c_has_irqs(struct p8_i2c_master *master) { struct proc_chip *chip; /* Centaur I2C doesn't have interrupts */ if (master->type == I2C_CENTAUR) return false; chip = get_chip(master->chip_id); /* The i2c interrurpt was only added to Murano DD2.1 and Venice * DD2.0. When operating without interrupts, we need to bump the * timeouts as we rely solely on the polls from Linux which can * be up to 2s apart ! * * Also we don't have interrupts for the Centaur i2c. */ switch (chip->type) { case PROC_CHIP_P8_MURANO: return chip->ec_level >= 0x21; case PROC_CHIP_P8_VENICE: return chip->ec_level >= 0x20; case PROC_CHIP_P8_NAPLES: return true; default: return false; } } static int p8_i2c_enable_irqs(struct p8_i2c_master *master) { int rc; /* Enable the interrupts */ rc = xscom_write(master->chip_id, master->xscom_base + I2C_INTR_COND_REG, I2C_STAT_ANY_ERR >> 16 | I2C_INTR_CMD_COMP | I2C_INTR_DATA_REQ); if (rc) prlog(PR_ERR, "I2C: Failed to enable the interrupts\n"); return rc; } static int p8_i2c_prog_watermark(struct p8_i2c_master *master) { uint64_t watermark; int rc; rc = xscom_read(master->chip_id, master->xscom_base + I2C_WATERMARK_REG, &watermark); if (rc) { prlog(PR_ERR, "I2C: Failed to read the WATERMARK_REG\n"); return rc; } /* Set the high/low watermark */ watermark = SETFIELD(I2C_WATERMARK_HIGH, watermark, I2C_FIFO_HI_LVL); watermark = SETFIELD(I2C_WATERMARK_LOW, watermark, I2C_FIFO_LO_LVL); rc = xscom_write(master->chip_id, master->xscom_base + I2C_WATERMARK_REG, watermark); if (rc) prlog(PR_ERR, "I2C: Failed to set high/low watermark level\n"); return rc; } static int p8_i2c_prog_mode(struct p8_i2c_master_port *port, bool enhanced_mode) { struct p8_i2c_master *master = port->master; struct i2c_request *req = list_top(&master->req_list, struct i2c_request, link); struct p8_i2c_request *request = container_of(req, struct p8_i2c_request, req); uint64_t mode, omode; int rc; rc = xscom_read(master->chip_id, master->xscom_base + I2C_MODE_REG, &mode); if (rc) { prlog(PR_ERR, "I2C: Failed to read the MODE_REG\n"); return rc; } omode = mode; mode = SETFIELD(I2C_MODE_PORT_NUM, mode, request->port_num); mode = SETFIELD(I2C_MODE_BIT_RATE_DIV, mode, port->bit_rate_div); if (enhanced_mode) mode |= I2C_MODE_ENHANCED; else mode &= ~I2C_MODE_ENHANCED; if (mode == omode) return 0; rc = xscom_write(master->chip_id, master->xscom_base + I2C_MODE_REG, mode); if (rc) prlog(PR_ERR, "I2C: Failed to write the MODE_REG\n"); return rc; } static void p8_i2c_complete_request(struct p8_i2c_master *master, struct i2c_request *req, int ret) { struct p8_i2c_request *request = container_of(req, struct p8_i2c_request, req); /* We only complete the current top level request */ assert(req == list_top(&master->req_list, struct i2c_request, link)); cancel_timer_async(&master->timeout); request->timeout = 0ul; list_del(&req->link); master->state = state_idle; req->result = ret; /* Schedule re-enabling of sensor cache */ if (master->occ_cache_dis) schedule_timer(&master->sensor_cache, msecs_to_tb(SENSOR_CACHE_EN_DELAY)); unlock(&master->lock); if (req->completion) req->completion(ret, req); /* req might have been freed at this point */ lock(&master->lock); } static int p8_i2c_engine_reset(struct p8_i2c_master_port *port) { struct p8_i2c_master *master = port->master; int rc; /* Reset the i2c engine */ rc = xscom_write(master->chip_id, master->xscom_base + I2C_RESET_I2C_REG, 0); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_RESET), "I2C: Failed " "to reset the i2c engine\n"); return rc; } /* Reprogram the watermark and mode */ rc = p8_i2c_prog_watermark(port->master); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_RESET), "I2C: Failed to" "program the WATERMARK_REG\n"); return rc; } rc = p8_i2c_prog_mode(port, false); if (rc) log_simple_error(&e_info(OPAL_RC_I2C_RESET), "I2C: Failed to" "program the MODE_REG\n"); return rc; } static void p8_i2c_translate_error(struct i2c_request *req, uint64_t status) { /* Assuming there are not more than one type of error simultaneously */ if (status & I2C_STAT_NACK_RCVD_ERR) req->result = OPAL_I2C_NACK_RCVD; else if (status & I2C_STAT_INVALID_CMD) req->result = OPAL_I2C_INVALID_CMD; else if (status & I2C_STAT_LBUS_PARITY_ERR) req->result = OPAL_I2C_LBUS_PARITY; else if (status & I2C_STAT_BKEND_OVERRUN_ERR) req->result = OPAL_I2C_BKEND_OVERRUN; else if (status & I2C_STAT_BKEND_ACCESS_ERR) req->result = OPAL_I2C_BKEND_ACCESS; else if (status & I2C_STAT_ARBT_LOST_ERR) req->result = OPAL_I2C_ARBT_LOST; else if (status & I2C_STAT_STOP_ERR) req->result = OPAL_I2C_STOP_ERR; else if (status & I2C_STAT_PSEUDO_TIMEOUT) req->result = OPAL_I2C_TIMEOUT; } static void p8_i2c_status_error(struct p8_i2c_master_port *port, struct i2c_request *req, uint64_t status) { struct p8_i2c_master *master = port->master; int rc; /* Display any error other than I2C_INTR_NACK_RCVD_ERR or * timeout since getting NACK's is normal if Linux is probing * the bus and timeouts will have already logged something. */ if (!(status & (I2C_STAT_NACK_RCVD_ERR | I2C_STAT_PSEUDO_TIMEOUT))) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Transfer error occurred\n"); p8_i2c_print_debug_info(port, req); } p8_i2c_translate_error(req, status); rc = p8_i2c_engine_reset(port); if (rc) goto exit; if (status & (I2C_STAT_LBUS_PARITY_ERR | I2C_STAT_ARBT_LOST_ERR | I2C_STAT_STOP_ERR)) { /* * Don't bother issuing a STOP command for those errors * just get rid of the current request and start off with * the fresh one in the list */ p8_i2c_complete_request(master, req, req->result); } else { /* * Reset the bus by issuing a STOP command to slave. * * Reprogram the mode register with 'enhanced bit' set */ rc = p8_i2c_prog_mode(port, true); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_RESET), "I2C: " "Failed to program the MODE_REG\n"); goto exit; } /* Enable the interrupt */ p8_i2c_enable_irqs(master); /* Send an immediate stop */ master->state = state_error; rc = xscom_write(master->chip_id, master->xscom_base + I2C_CMD_REG, I2C_CMD_WITH_STOP); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_RESET), "I2C: " "Failed to issue immediate STOP\n"); goto exit; } } return; exit: p8_i2c_complete_request(master, req, req->result); } static int p8_i2c_fifo_read(struct p8_i2c_master *master, uint8_t *buf, uint32_t count) { uint64_t fifo; uint32_t i; int rc = 0; for (i = 0; i < count; i++, buf++) { rc = xscom_read(master->chip_id, master->xscom_base + I2C_FIFO_REG, &fifo); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Failed to read the fifo\n"); break; } *buf = GETFIELD(I2C_FIFO, fifo); } return rc; } static int p8_i2c_fifo_write(struct p8_i2c_master *master, uint8_t *buf, uint32_t count) { uint64_t fifo; uint32_t i; int rc = 0; for (i = 0; i < count; i++, buf++) { fifo = SETFIELD(I2C_FIFO, 0ull, *buf); rc = xscom_write(master->chip_id, master->xscom_base + I2C_FIFO_REG, fifo); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Failed to write the fifo\n"); break; } } return rc; } static void p8_i2c_status_data_request(struct p8_i2c_master *master, struct i2c_request *req, uint64_t status) { uint32_t fifo_count, fifo_free, count; uint8_t *buf; int rc = 0; fifo_count = GETFIELD(I2C_STAT_FIFO_ENTRY_COUNT, status); fifo_free = master->fifo_size - fifo_count; DBG("Data request, state=%d fifo_count=%d/%d bytes_sent=%d\n", master->state, fifo_count, master->fifo_size, master->bytes_sent); switch(master->state) { case state_offset: /* We assume the offset can always be written in one go */ if (fifo_free < req->offset_bytes) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Fifo too small for offset !\n"); rc = OPAL_HARDWARE; } else { rc = p8_i2c_fifo_write(master, master->obuf, req->offset_bytes); } /* For read, wait address phase to complete */ if (rc || req->op != SMBUS_WRITE) break; /* For writes, transition to data phase now */ master->state = state_data; fifo_free -= req->offset_bytes; /* Fall through */ case state_data: /* Sanity check */ if (master->bytes_sent >= req->rw_len) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: " "Data req with no data to send sent=%d " "req=%d\n", master->bytes_sent, req->rw_len); rc = OPAL_HARDWARE; break; } /* Get next chunk */ buf = req->rw_buf + master->bytes_sent; count = req->rw_len - master->bytes_sent; /* Check direction */ if (req->op == I2C_READ || req->op == SMBUS_READ) { if (count > fifo_count) count = fifo_count; rc = p8_i2c_fifo_read(master, buf, count); } else { if (count > fifo_free) count = fifo_free; rc = p8_i2c_fifo_write(master, buf, count); } if (rc == 0) master->bytes_sent += count; break; default: log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Invalid " "state %d in data req !\n", master->state); rc = OPAL_WRONG_STATE; } if (rc) p8_i2c_complete_request(master, req, rc); else p8_i2c_enable_irqs(master); } static void p8_i2c_complete_offset(struct p8_i2c_master *master, struct i2c_request *req) { uint64_t cmd; int rc = 0; DBG("Completing offset phase\n"); /* If it's a write, we should only get here for empty * write commands */ if (req->op == SMBUS_WRITE && req->rw_len != 0) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Write " "completion in offset state !\n"); rc = OPAL_HARDWARE; goto complete; } /* Switch to data phase */ master->state = state_data; /* If it's not a read command, or there are no data to read, * then we complete the command */ if (req->op != SMBUS_READ || req->rw_len == 0) goto complete; /* Otherwise, let's start the data phase */ cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR | I2C_CMD_WITH_STOP | I2C_CMD_READ_NOT_WRITE; cmd = SETFIELD(I2C_CMD_DEV_ADDR, cmd, req->dev_addr); cmd = SETFIELD(I2C_CMD_LEN_BYTES, cmd, req->rw_len); DBG("Command: %016llx, state: %d\n", cmd, master->state); /* Send command */ rc = xscom_write(master->chip_id, master->xscom_base + I2C_CMD_REG, cmd); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Failed " "to write the CMD_REG\n"); goto complete; } /* Enable the interrupts */ p8_i2c_enable_irqs(master); return; complete: p8_i2c_complete_request(master, req, rc); } static void p8_i2c_status_cmd_completion(struct p8_i2c_master *master, struct i2c_request *req) { int rc; DBG("Command completion, state=%d bytes_sent=%d\n", master->state, master->bytes_sent); /* If we complete an offset, we probably need to transition * do a data read, check if that all makes sense */ if (master->state == state_offset) { p8_i2c_complete_offset(master, req); return; } /* If we are not already in error state, check if we have * completed our data transfer properly */ if (master->state != state_error && master->bytes_sent != req->rw_len) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Request " "complete with residual data req=%d done=%d\n", req->rw_len, master->bytes_sent); /* Should we error out here ? */ } rc = master->state == state_error ? req->result : OPAL_SUCCESS; p8_i2c_complete_request(master, req, rc); } static void p8_i2c_check_status(struct p8_i2c_master *master) { struct p8_i2c_master_port *port; struct i2c_request *req; uint64_t status; int rc; /* If we are idle, just return, we'll catch error conditions * when we next try to enqueue a request */ if (master->state == state_idle) return; /* Read status register */ rc = xscom_read(master->chip_id, master->xscom_base + I2C_STAT_REG, &status); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Failed " "to read the STAT_REG\n"); return; } /* Nothing happened ? Go back */ if (!(status & (I2C_STAT_ANY_ERR | I2C_STAT_DATA_REQ | I2C_STAT_CMD_COMP))) return; DBG("Non-0 status: %016llx\n", status); /* Mask the interrupts for this engine */ rc = xscom_write(master->chip_id, master->xscom_base + I2C_INTR_REG, ~I2C_INTR_ALL); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Failed " "to disable the interrupts\n"); return; } /* No request ? That's not normal ! Bail out without re-enabling * the interrupt */ req = list_top(&master->req_list, struct i2c_request, link); if (req == NULL) { log_simple_error(&e_info(OPAL_RC_I2C_TRANSFER), "I2C: Interrupt with no request" ", status=0x%016llx\n", status); return; } /* Get port for current request */ port = container_of(req->bus, struct p8_i2c_master_port, bus); /* Handle the status in that order: errors, data requests and * command completion. */ if (status & I2C_STAT_ANY_ERR) { /* Mask status to avoid some unrelated bit overwriting * our pseudo-status "timeout" bit 63 */ p8_i2c_status_error(port, req, status & I2C_STAT_ANY_ERR); } else if (status & I2C_STAT_DATA_REQ) p8_i2c_status_data_request(master, req, status); else if (status & I2C_STAT_CMD_COMP) p8_i2c_status_cmd_completion(master, req); } static int p8_i2c_check_initial_status(struct p8_i2c_master_port *port) { struct p8_i2c_master *master = port->master; uint64_t status, estat; int rc; master->recovery_pass++; /* Read status register */ rc = xscom_read(master->chip_id, master->xscom_base + I2C_STAT_REG, &status); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: Failed " "to read the STAT_REG\n"); return rc; } rc = xscom_read(master->chip_id, master->xscom_base + I2C_EXTD_STAT_REG, &estat); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: Failed " "to read the EXTD_STAT_REG\n"); return rc; } if (estat & (I2C_EXTD_STAT_I2C_BUSY | I2C_EXTD_STAT_SELF_BUSY)) { DBG("Initial estat busy ! %016llx\n", estat); /* Just a warning for now */ } /* Nothing happened ? Go back */ if (status & I2C_STAT_ANY_ERR) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: " "Initial error status 0x%016llx\n", status); if (master->recovery_pass > 1) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: " "Error stuck, aborting !!\n"); return OPAL_HARDWARE; } /* Mark state as "recovery" to block any other activity */ master->state = state_recovery; /* Reset the engine */ p8_i2c_engine_reset(port); /* Delay 5ms for bus to settle */ schedule_timer(&master->recovery, msecs_to_tb(5)); unlock(&master->lock); return OPAL_BUSY; } /* Still busy ? */ if (!(status & I2C_STAT_CMD_COMP)) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: Initial " "command complete not set\n"); if (master->recovery_pass > 5) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: " "Command stuck, aborting !!\n"); return OPAL_HARDWARE; } master->state = state_recovery; /* Delay 5ms for bus to settle */ schedule_timer(&master->recovery, msecs_to_tb(5)); unlock(&master->lock); return OPAL_BUSY; } master->recovery_pass = 0; return 0; } static int p8_i2c_start_request(struct p8_i2c_master *master, struct i2c_request *req) { struct p8_i2c_master_port *port; struct p8_i2c_request *request = container_of(req, struct p8_i2c_request, req); uint64_t cmd, now, poll_interval; int64_t rc, tbytes; DBG("Starting req %d len=%d addr=%02x (offset=%x)\n", req->op, req->rw_len, req->dev_addr, req->offset); /* Get port */ port = container_of(req->bus, struct p8_i2c_master_port, bus); /* Check if we need to disable the OCC cache first */ if (master->type == I2C_CENTAUR && !master->occ_cache_dis) { DBG("Disabling OCC cache...\n"); rc = centaur_disable_sensor_cache(master->chip_id); if (rc < 0) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: Failed " "to disable the sensor cache\n"); return rc; } master->occ_cache_dis = true; /* Do we need to wait ? */ if (rc > 0) { DBG("Waiting %lld\n", rc); master->state = state_occache_dis; schedule_timer(&master->recovery, rc); return 0; } } /* Convert the offset if needed */ if (req->offset_bytes) { int i; for (i = 0; i < req->offset_bytes; i++) { uint8_t b; b = req->offset >> (8 * (req->offset_bytes - i - 1)); master->obuf[i] = b; } DBG("Offset %d bytes: %02x %02x %02x %02x\n", req->offset_bytes, master->obuf[0], master->obuf[1], master->obuf[2], master->obuf[3]); } /* Program mode register */ rc = p8_i2c_prog_mode(port, false); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: Failed " "to program the MODE_REG\n"); return rc; } /* Check status */ rc = p8_i2c_check_initial_status(port); if (rc != OPAL_BUSY) master->recovery_pass = 0; if (rc) return rc; /* Initialize bytes_sent */ master->bytes_sent = 0; /* Set up the command register */ cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR; cmd = SETFIELD(I2C_CMD_DEV_ADDR, cmd, req->dev_addr); switch (req->op) { case I2C_READ: cmd |= I2C_CMD_READ_NOT_WRITE; /* Fall through */ case I2C_WRITE: cmd |= I2C_CMD_WITH_STOP; cmd = SETFIELD(I2C_CMD_LEN_BYTES, cmd, req->rw_len); master->state = state_data; break; case SMBUS_READ: cmd = SETFIELD(I2C_CMD_LEN_BYTES, cmd, req->offset_bytes); master->state = state_offset; break; case SMBUS_WRITE: cmd |= I2C_CMD_WITH_STOP; cmd = SETFIELD(I2C_CMD_LEN_BYTES, cmd, req->rw_len + req->offset_bytes); master->state = state_offset; break; default: return OPAL_PARAMETER; } DBG("Command: %016llx, state: %d\n", cmd, master->state); /* Send command */ rc = xscom_write(master->chip_id, master->xscom_base + I2C_CMD_REG, cmd); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_START_REQ), "I2C: Failed " "to write the CMD_REG\n"); return rc; } /* Enable the interrupts */ p8_i2c_enable_irqs(master); /* Run a poll timer for boot cases or non-working interrupts * cases */ if (!opal_booting() && master->irq_ok) poll_interval = TIMER_POLL; else poll_interval = master->poll_interval; now = schedule_timer(&master->poller, poll_interval); /* Calculate and start timeout */ if (request->timeout) { request->timeout += now; } else { tbytes = req->rw_len + req->offset_bytes + 2; request->timeout = now + tbytes * master->byte_timeout; } /* Start the timeout */ schedule_timer_at(&master->timeout, request->timeout); return OPAL_SUCCESS; } static void p8_i2c_check_work(struct p8_i2c_master *master) { struct i2c_request *req; int rc; while (master->state == state_idle && !list_empty(&master->req_list)) { req = list_top(&master->req_list, struct i2c_request, link); rc = p8_i2c_start_request(master, req); if (rc && rc != OPAL_BUSY) p8_i2c_complete_request(master, req, rc); } } static int p8_i2c_queue_request(struct i2c_request *req) { struct i2c_bus *bus = req->bus; struct p8_i2c_master_port *port = container_of(bus, struct p8_i2c_master_port, bus); struct p8_i2c_master *master = port->master; int rc = 0; /* Parameter check */ if (req->rw_len > I2C_MAX_TFR_LEN) { prlog(PR_ERR, "I2C: Too large transfer %d bytes\n", req->rw_len); return OPAL_PARAMETER; } if (req->offset_bytes > 4) { prlog(PR_ERR, "I2C: Invalid offset size %d\n", req->offset_bytes); return OPAL_PARAMETER; } lock(&master->lock); list_add_tail(&master->req_list, &req->link); p8_i2c_check_work(master); unlock(&master->lock); return rc; } static struct i2c_request *p8_i2c_alloc_request(struct i2c_bus *bus) { struct p8_i2c_master_port *port = container_of(bus, struct p8_i2c_master_port, bus); struct p8_i2c_request *request; request = zalloc(sizeof(*request)); if (!request) { prlog(PR_ERR, "I2C: Failed to allocate i2c request\n"); return NULL; } request->port_num = port->port_num; request->req.bus = bus; return &request->req; } static void p8_i2c_free_request(struct i2c_request *req) { struct p8_i2c_request *request = container_of(req, struct p8_i2c_request, req); free(request); } static void p8_i2c_set_request_timeout(struct i2c_request *req, uint64_t duration) { struct p8_i2c_request *request = container_of(req, struct p8_i2c_request, req); request->timeout = msecs_to_tb(duration); } static uint64_t p8_i2c_run_request(struct i2c_request *req) { struct i2c_bus *bus = req->bus; struct p8_i2c_master_port *port = container_of(bus, struct p8_i2c_master_port, bus); struct p8_i2c_master *master = port->master; uint64_t poll_interval = 0; lock(&master->lock); p8_i2c_check_status(master); p8_i2c_check_work(master); poll_interval = master->poll_interval; unlock(&master->lock); return poll_interval; } static inline uint32_t p8_i2c_get_bit_rate_divisor(uint32_t lb_freq, uint32_t bus_speed) { assert(bus_speed > 0); return (((lb_freq / bus_speed) - 1) / 4); } static inline uint64_t p8_i2c_get_poll_interval(uint32_t bus_speed) { uint64_t usec; assert(bus_speed > 0); /* Polling Interval = 8 * (1/bus_speed) * (1/10) -> convert to uSec */ usec = ((8 * USEC_PER_SEC) / (10 * bus_speed)); return usecs_to_tb(usec); } static void p8_i2c_timeout(struct timer *t __unused, void *data, uint64_t now) { struct p8_i2c_master_port *port; struct p8_i2c_master *master = data; struct p8_i2c_request *request; struct i2c_request *req; lock(&master->lock); /* This could be spurrious ... */ if (master->state == state_idle) { DBG("I2C: Timeout in idle state\n"); goto exit; } /* We might still be spurrious timer, we need to ensure that the * head request is indeed old enough to be the one timing out */ req = list_top(&master->req_list, struct i2c_request, link); if (req == NULL) { DBG("I2C: Timeout with no" " pending request state=%d\n", master->state); goto exit; } request = container_of(req, struct p8_i2c_request, req); if (tb_compare(now, request->timeout) == TB_ABEFOREB) { DBG("I2C: Timeout with request not expired\n"); goto exit; } request->timeout = 0ul; port = container_of(req->bus, struct p8_i2c_master_port, bus); /* Allright, we have a request and it has timed out ... */ log_simple_error(&e_info(OPAL_RC_I2C_TIMEOUT), "I2C: Request timeout !\n"); p8_i2c_print_debug_info(port, req); /* Use the standard error path */ p8_i2c_status_error(port, req, I2C_STAT_PSEUDO_TIMEOUT); exit: unlock(&master->lock); } static void p8_i2c_recover(struct timer *t __unused, void *data, uint64_t now __unused) { struct p8_i2c_master *master = data; lock(&master->lock); assert(master->state == state_recovery || master->state == state_occache_dis); master->state = state_idle; /* We may or may not still have work pending, re-enable the sensor cache * immediately if we don't (we just waited the recovery time so there is * little point waiting longer). */ if (master->occ_cache_dis && list_empty(&master->req_list)) { DBG("Re-enabling OCC cache after recovery\n"); centaur_enable_sensor_cache(master->chip_id); master->occ_cache_dis = false; } /* Re-check for new work */ p8_i2c_check_work(master); unlock(&master->lock); } static void p8_i2c_enable_scache(struct timer *t __unused, void *data, uint64_t now __unused) { struct p8_i2c_master *master = data; lock(&master->lock); /* Check if we are still idle */ if (master->state == state_idle && master->occ_cache_dis) { DBG("Re-enabling OCC cache\n"); centaur_enable_sensor_cache(master->chip_id); master->occ_cache_dis = false; } unlock(&master->lock); } static void p8_i2c_poll(struct timer *t __unused, void *data, uint64_t now) { struct p8_i2c_master *master = data; /* * This is called when the interrupt isn't functional or * generally from the opal pollers, so fast while booting * and slowly when Linux is up. */ /* Lockless fast bailout */ if (master->state == state_idle) return; lock(&master->lock); p8_i2c_check_status(master); if (master->state != state_idle) schedule_timer_at(&master->poller, now + master->poll_interval); p8_i2c_check_work(master); unlock(&master->lock); } void p8_i2c_interrupt(uint32_t chip_id) { struct proc_chip *chip = get_chip(chip_id); struct p8_i2c_master *master = NULL; assert(chip); list_for_each(&chip->i2cms, master, link) { /* Lockless fast bailout (shared interrupt) */ if (master->state == state_idle) continue; lock(&master->lock); /* Run the state machine */ p8_i2c_check_status(master); /* Check for new work */ p8_i2c_check_work(master); unlock(&master->lock); } } static const char *compat[] = { "ibm,power8-i2cm", "ibm,centaur-i2cm" }; static void p8_i2c_add_bus_prop(struct p8_i2c_master_port *port) { const struct dt_property *c, *p; struct dt_node *np = port->bus.dt_node; char name[32]; c = dt_find_property(np, "compatible"); p = dt_find_property(np, "ibm,port-name"); if (!c) { if (port->master->type == I2C_POWER8) dt_add_property_strings(np, "compatible", "ibm,power8-i2c-port", "ibm,opal-i2c"); else if (port->master->type == I2C_CENTAUR) dt_add_property_strings(np, "compatible", "ibm,centaur-i2c-port", "ibm,opal-i2c"); } if (!p) { if (port->master->type == I2C_POWER8) snprintf(name, sizeof(name), "p8_%08x_e%dp%d", port->master->chip_id, port->master->engine_id, port->port_num); else if (port->master->type == I2C_CENTAUR) snprintf(name, sizeof(name), "cen_%08x_e%dp%d", port->master->chip_id, port->master->engine_id, port->port_num); dt_add_property_string(np, "ibm,port-name", name); } } static void p8_i2c_init_one(struct dt_node *i2cm, enum p8_i2c_master_type type) { struct p8_i2c_master_port *port; uint32_t lb_freq, count, max_bus_speed; struct dt_node *i2cm_port; struct p8_i2c_master *master; struct list_head *chip_list; uint64_t ex_stat; static bool irq_printed; int64_t rc; master = zalloc(sizeof(*master)); if (!master) { log_simple_error(&e_info(OPAL_RC_I2C_INIT), "I2C: Failed to allocate master " "structure\n"); return; } master->type = type; /* Local bus speed in Hz */ lb_freq = dt_prop_get_u32(i2cm, "clock-frequency"); /* XXX HACK for bad HB value */ if (lb_freq == 600000000) { prlog(PR_ERR, "I2C: Fixing up HB bad clock freq !\n"); lb_freq = 50000000; } /* Initialise the i2c master structure */ master->state = state_idle; master->chip_id = dt_get_chip_id(i2cm); master->engine_id = dt_prop_get_u32(i2cm, "chip-engine#"); master->xscom_base = dt_get_address(i2cm, 0, NULL); if (master->type == I2C_CENTAUR) { struct centaur_chip *centaur = get_centaur(master->chip_id); if (centaur == NULL) { log_simple_error(&e_info(OPAL_RC_I2C_INIT), "I2C: Failed to get centaur 0x%x ", master->chip_id); free(master); return; } chip_list = ¢aur->i2cms; /* Detect bad device-tree from HostBoot giving us bogus * i2c masters */ if (master->engine_id > 0) { prlog(PR_ERR, "I2C: Skipping Centaur Master #1\n"); free(master); return; } } else { struct proc_chip *chip = get_chip(master->chip_id); assert(chip); chip_list = &chip->i2cms; } init_timer(&master->timeout, p8_i2c_timeout, master); init_timer(&master->poller, p8_i2c_poll, master); init_timer(&master->recovery, p8_i2c_recover, master); init_timer(&master->sensor_cache, p8_i2c_enable_scache, master); prlog(PR_INFO, "I2C: Chip %08x Eng. %d\n", master->chip_id, master->engine_id); /* Disable OCC cache during inits */ if (master->type == I2C_CENTAUR) { rc = centaur_disable_sensor_cache(master->chip_id); if (rc < 0) { log_simple_error(&e_info(OPAL_RC_I2C_INIT), "I2C: " "Error %lld disabling sensor cache\n", rc); /* Ignore error and move on ... */ } else time_wait(rc); } rc = xscom_read(master->chip_id, master->xscom_base + I2C_EXTD_STAT_REG, &ex_stat); if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_INIT), "I2C: " "Failed to read EXTD_STAT_REG\n"); if (master->type == I2C_CENTAUR) centaur_enable_sensor_cache(master->chip_id); free(master); return; } master->fifo_size = GETFIELD(I2C_EXTD_STAT_FIFO_SIZE, ex_stat); list_head_init(&master->req_list); /* Check if interrupt is usable */ master->irq_ok = p8_i2c_has_irqs(master); if (!irq_printed) { irq_printed = true; prlog(PR_INFO, "I2C: Interrupts %sfunctional\n", master->irq_ok ? "" : "non-"); } /* Program the watermark register */ rc = p8_i2c_prog_watermark(master); /* Re-enable the sensor cache, we aren't touching HW anymore */ if (master->type == I2C_CENTAUR) centaur_enable_sensor_cache(master->chip_id); /* Handle errors from p8_i2c_prog_watermark */ if (rc) { log_simple_error(&e_info(OPAL_RC_I2C_INIT), "I2C: Failed to program the " "WATERMARK_REG\n"); free(master); return; } /* Allocate ports driven by this master */ count = 0; dt_for_each_child(i2cm, i2cm_port) count++; port = zalloc(sizeof(*port) * count); if (!port) { log_simple_error(&e_info(OPAL_RC_I2C_INIT), "I2C: Insufficient memory\n"); free(master); return; } /* Add master to chip's list */ list_add_tail(chip_list, &master->link); max_bus_speed = 0; dt_for_each_child(i2cm, i2cm_port) { uint32_t speed; port->port_num = dt_prop_get_u32(i2cm_port, "reg"); port->master = master; speed = dt_prop_get_u32(i2cm_port, "bus-frequency"); if (speed > max_bus_speed) max_bus_speed = speed; port->bit_rate_div = p8_i2c_get_bit_rate_divisor(lb_freq, speed); port->bus.dt_node = i2cm_port; port->bus.queue_req = p8_i2c_queue_request; port->bus.alloc_req = p8_i2c_alloc_request; port->bus.free_req = p8_i2c_free_request; port->bus.set_req_timeout = p8_i2c_set_request_timeout; port->bus.run_req = p8_i2c_run_request; i2c_add_bus(&port->bus); /* Add OPAL properties to the bus node */ p8_i2c_add_bus_prop(port); prlog(PR_INFO, " P%d: <%s> %d kHz\n", port->port_num, (char *)dt_prop_get(i2cm_port, "ibm,port-name"), speed/1000); port++; } /* When at runtime and we have the i2c irq, we just use it * (see p8_i2c_start_request), but in the situation where * one of those isn't the case (e.g. during boot), we need * a better poll interval to efficiently crank the i2c machine. * poll_interval is that interval. */ master->poll_interval = (max_bus_speed) ? p8_i2c_get_poll_interval(max_bus_speed) : TIMER_POLL; master->byte_timeout = master->irq_ok ? msecs_to_tb(I2C_TIMEOUT_IRQ_MS) : msecs_to_tb(I2C_TIMEOUT_POLL_MS); } void p8_i2c_init(void) { struct dt_node *i2cm; int i; for (i = 0; i < MAX_I2C_TYPE; i++) { dt_for_each_compatible(dt_root, i2cm, compat[i]) p8_i2c_init_one(i2cm, i); } }