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Diffstat (limited to 'core/i2c.c')
| -rw-r--r-- | core/i2c.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/core/i2c.c b/core/i2c.c new file mode 100644 index 0000000..2eb77db --- /dev/null +++ b/core/i2c.c @@ -0,0 +1,116 @@ +/* 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. + */ + +#include <skiboot.h> +#include <i2c.h> +#include <opal.h> +#include <device.h> +#include <opal-msg.h> + +LIST_HEAD(i2c_bus_list); + +/* Used to assign OPAL IDs */ +static uint32_t i2c_next_bus; + +void i2c_add_bus(struct i2c_bus *bus) +{ + bus->opal_id = ++i2c_next_bus; + dt_add_property_cells(bus->dt_node, "ibm,opal-id", bus->opal_id); + + list_add_tail(&i2c_bus_list, &bus->link); +} + +struct i2c_bus *i2c_find_bus_by_id(uint32_t opal_id) +{ + struct i2c_bus *bus; + + list_for_each(&i2c_bus_list, bus, link) { + if (bus->opal_id == opal_id) + return bus; + } + return NULL; +} + +static void opal_i2c_request_complete(int rc, struct i2c_request *req) +{ + uint64_t token = (uint64_t)(unsigned long)req->user_data; + + opal_queue_msg(OPAL_MSG_ASYNC_COMP, NULL, NULL, token, rc); + i2c_free_req(req); +} + +static int opal_i2c_request(uint64_t async_token, uint32_t bus_id, + struct opal_i2c_request *oreq) +{ + struct i2c_bus *bus = NULL; + struct i2c_request *req; + int rc; + + if (oreq->flags & OPAL_I2C_ADDR_10) + return OPAL_UNSUPPORTED; + + bus = i2c_find_bus_by_id(bus_id); + if (!bus) { + prlog(PR_ERR, "I2C: Invalid 'bus_id' passed to the OPAL\n"); + return OPAL_PARAMETER; + } + + req = i2c_alloc_req(bus); + if (!req) { + prlog(PR_ERR, "I2C: Failed to allocate 'i2c_request'\n"); + return OPAL_NO_MEM; + } + + switch(oreq->type) { + case OPAL_I2C_RAW_READ: + req->op = I2C_READ; + break; + case OPAL_I2C_RAW_WRITE: + req->op = I2C_WRITE; + break; + case OPAL_I2C_SM_READ: + req->op = SMBUS_READ; + req->offset = oreq->subaddr; + req->offset_bytes = oreq->subaddr_sz; + break; + case OPAL_I2C_SM_WRITE: + req->op = SMBUS_WRITE; + req->offset = oreq->subaddr; + req->offset_bytes = oreq->subaddr_sz; + break; + default: + bus->free_req(req); + return OPAL_PARAMETER; + } + req->dev_addr = oreq->addr; + req->rw_len = oreq->size; + req->rw_buf = (void *)oreq->buffer_ra; + req->completion = opal_i2c_request_complete; + req->user_data = (void *)(unsigned long)async_token; + req->bus = bus; + + /* Finally, queue the OPAL i2c request and return */ + rc = i2c_queue_req(req); + if (rc) { + i2c_free_req(req); + return rc; + } + + return OPAL_ASYNC_COMPLETION; +} +opal_call(OPAL_I2C_REQUEST, opal_i2c_request, 3); + + |