/* SPDX-License-Identifier: GPL-2.0-only */ #include #include #include #include #include #include #define SMU_MESG_RESP_TIMEOUT 0x00 #define SMU_MESG_RESP_OK 0x01 /* returns SMU_MESG_RESP_OK, SMU_MESG_RESP_TIMEOUT or a negative number */ static int32_t smu_poll_response(bool print_command_duration) { struct stopwatch sw; const long timeout_ms = 10 * MSECS_PER_SEC; int32_t result; stopwatch_init_msecs_expire(&sw, timeout_ms); do { result = smn_read32(SMN_SMU_MESG_RESP); if (result) { if (print_command_duration) printk(BIOS_SPEW, "SMU command consumed %ld usecs\n", stopwatch_duration_usecs(&sw)); return result; } } while (!stopwatch_expired(&sw)); printk(BIOS_ERR, "Error: timeout sending SMU message\n"); return SMU_MESG_RESP_TIMEOUT; } /* * Send a message and bi-directional payload to the SMU. SMU response, if any, is returned via * *arg. */ enum cb_err send_smu_message(enum smu_message_id message_id, struct smu_payload *arg) { size_t i; /* wait until SMU can process a new request; don't care if an old request failed */ if (smu_poll_response(false) == SMU_MESG_RESP_TIMEOUT) return CB_ERR; /* clear response register */ smn_write32(SMN_SMU_MESG_RESP, 0); /* populate arguments */ for (i = 0 ; i < SMU_NUM_ARGS ; i++) smn_write32(SMN_SMU_MESG_ARG(i), arg->msg[i]); /* send message to SMU */ smn_write32(SMN_SMU_MESG_ID, message_id); /* wait until SMU has processed the message and check if it was successful */ if (smu_poll_response(true) != SMU_MESG_RESP_OK) return CB_ERR; /* copy returned values */ for (i = 0 ; i < SMU_NUM_ARGS ; i++) arg->msg[i] = smn_read32(SMN_SMU_MESG_ARG(i)); return CB_SUCCESS; }