| // SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later |
| /* Copyright 2013-2018 IBM Corp. */ |
| |
| #include <skiboot.h> |
| #include <opal-api.h> |
| #include <i2c.h> |
| |
| #include "tpm_i2c_interface.h" |
| #include "../status_codes.h" |
| |
| /* TPMs can clock strech I2C operations for a LOOOOOOONG */ |
| #define I2C_BYTE_TIMEOUT_MS 2000 /* 2000ms/byte timeout */ |
| |
| /** |
| * tpm_i2c_request_send - send request to i2c bus |
| * @tpm_bus_id: i2c bus id |
| * @tpm_dev_addr: address of the tpm device |
| * @read_write: SMBUS_READ or SMBUS_WRITE |
| * @offset: any of the I2C interface offset defined |
| * @offset_bytes: offset size in bytes |
| * @buf: data to be read or written |
| * @buflen: buf length |
| * |
| * This interacts with skiboot i2c API to send an I2C request to the tpm |
| * device |
| * |
| * Returns: Zero on success otherwise a negative error code |
| */ |
| int tpm_i2c_request_send(struct tpm_dev *tpm_device, int read_write, |
| uint32_t offset, uint32_t offset_bytes, void* buf, |
| size_t buflen) |
| { |
| int rc, timeout; |
| |
| /* |
| * Set the request timeout to 30ms per byte. Otherwise, we get |
| * an I2C master timeout for all requests sent to the device |
| * since the I2C master's timeout is too short (1ms per byte). |
| */ |
| timeout = (buflen + offset_bytes + 2) * I2C_BYTE_TIMEOUT_MS; |
| |
| rc = i2c_request_send(tpm_device->bus_id, tpm_device->i2c_addr, |
| read_write, offset, offset_bytes, buf, buflen, |
| timeout); |
| if (rc == OPAL_PARAMETER) |
| return STB_ARG_ERROR; |
| else if (rc < 0) |
| return STB_DRIVER_ERROR; |
| return 0; |
| } |