pkarashchenko commented on code in PR #10483: URL: https://github.com/apache/nuttx/pull/10483#discussion_r1316402885
########## arch/risc-v/src/mpfs/mpfs_dsn.c: ########## @@ -0,0 +1,154 @@ +/**************************************************************************** + * arch/risc-v/src/mpfs/mpfs_dsn.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> +#include <errno.h> +#include <unistd.h> +#include "mpfs_dsn.h" +#include "riscv_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#define MPFS_SCBCTRL_BASE 0x37020000ul +#define SERVICES_CR_OFFSET 0x50 +#define SERVICES_SR_OFFSET 0x54 + +#define SERVICES_CR (MPFS_SCBCTRL_BASE + SERVICES_CR_OFFSET) +#define SERVICES_SR (MPFS_SCBCTRL_BASE + SERVICES_SR_OFFSET) + +/* Command bits */ + +#define SCBCTRL_SERVICESCR_REQ (1 << 0) + +/* Status bits */ + +#define SCBCTRL_SERVICESSR_BUSY (1 << 1) + +/* 2kB long mailbox. */ + +#define MSS_SCBMAILBOX 0x37020800ul + +/* Retry count */ + +#define RETRIES 500 + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: mpfs_read_dsn + * + * Description: + * Read n bytes of the device serial number. Full serial number is 16 bytes + * + * Parameters: + * dsn - A pointer to the destination buffer + * len - Number of bytes to read + * + * Returned Value: + * Number of bytes read, -ETIMEDOUT on error + * + ****************************************************************************/ + +int mpfs_read_dsn(uint8_t *dsn, size_t len) +{ + uint32_t reg; + uint8_t *p = (uint8_t *)MSS_SCBMAILBOX; + irqstate_t flags = enter_critical_section(); + unsigned retries = RETRIES; + + /* Wait until the system controller is not busy. + * Read the SN inside critical section, just in case someone else is + * using the system controller services + */ + + while ((getreg32(SERVICES_SR) & SCBCTRL_SERVICESSR_BUSY) && --retries > 0) + { + leave_critical_section(flags); + usleep(1000); + flags = enter_critical_section(); Review Comment: I need to double check, but I think it should be fine jus to ```suggestion usleep(1000); ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
