/* * Copyright (C) 2016 The Android Open Source Project * * 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 <plat/inc/gpio.h> #include <plat/inc/usart.h> #include <plat/inc/pwr.h> #include <usart.h> #include <gpio.h> struct StmUsart { volatile uint16_t SR; uint8_t unused0[2]; volatile uint16_t DR; uint8_t unused1[2]; volatile uint16_t BRR; uint8_t unused2[2]; volatile uint16_t CR1; uint8_t unused3[2]; volatile uint16_t CR2; uint8_t unused4[2]; volatile uint16_t CR3; uint8_t unused5[2]; volatile uint16_t GTPR; uint8_t unused6[2]; }; static const uint32_t mUsartPorts[] = { USART1_BASE, USART2_BASE, USART3_BASE, UART4_BASE, UART5_BASE, USART6_BASE, }; static const uint32_t mUsartPeriphs[] = { PERIPH_APB2_USART1, PERIPH_APB1_USART2, PERIPH_APB1_USART3, PERIPH_APB1_UART4, PERIPH_APB1_UART5, PERIPH_APB2_USART6, }; static uint8_t mUsartBusses[] = { PERIPH_BUS_APB2, PERIPH_BUS_APB1, PERIPH_BUS_APB1, PERIPH_BUS_APB1, PERIPH_BUS_APB1, PERIPH_BUS_APB2, }; static bool mUsartHasFlowControl[] = { true, true, true, false, false, true, }; static enum StmGpioAltFunc mUsartAlt[] = { GPIO_AF_USART1, GPIO_AF_USART2, GPIO_AF00, GPIO_AF00, GPIO_AF00, GPIO_AF_USART6, }; void usartOpen(struct usart* __restrict usart, UsartPort port, uint32_t txGpioNum, uint32_t rxGpioNum, uint32_t baud, UsartDataBitsCfg data_bits, UsatStopBitsCfg stop_bits, UsartParityCfg parity, UsartFlowControlCfg flow_control) { static const uint16_t stopBitsVals[] = {0x1000, 0x0000, 0x3000, 0x2000}; // indexed by UsatStopBitsCfg static const uint16_t wordLengthVals[] = {0x0000, 0x1000}; // indexed by UsartDataBitsCfg static const uint16_t parityVals[] = {0x0000, 0x0400, 0x0600}; // indexed by UsartParityCfg static const uint16_t flowCtrlVals[] = {0x0000, 0x0100, 0x0200, 0x0300}; // indexed by UsartFlowControlCfg struct StmUsart *block = (struct StmUsart*)mUsartPorts[usart->unit = --port]; uint32_t baseClk, div, intPart, fraPart; /* configure tx/rx gpios */ usart->rx = gpioRequest(rxGpioNum); /* rx */ gpioConfigAlt(usart->rx, GPIO_SPEED_LOW, GPIO_PULL_UP, GPIO_OUT_PUSH_PULL, mUsartAlt[port]); usart->tx = gpioRequest(txGpioNum); /* tx */ gpioConfigAlt(usart->tx, GPIO_SPEED_LOW, GPIO_PULL_UP, GPIO_OUT_PUSH_PULL, mUsartAlt[port]); /* enable clock */ pwrUnitClock(mUsartBusses[port], mUsartPeriphs[port], true); /* sanity checks */ if (!mUsartHasFlowControl[port]) flow_control = USART_FLOW_CONTROL_NONE; /* basic config as required + oversample by 8, tx+rx on */ block->CR2 = (block->CR2 &~ 0x3000) | stopBitsVals[stop_bits]; block->CR1 = (block->CR1 &~ 0x1600) | wordLengthVals[data_bits] | parityVals[parity] | 0x800C; block->CR3 = (block->CR3 &~ 0x0300) | flowCtrlVals[flow_control]; /* clocking calc */ baseClk = pwrGetBusSpeed(mUsartBusses[port]); div = (baseClk * 25) / (baud * 2); intPart = div / 100; fraPart = div % 100; /* clocking munging */ intPart = intPart << 4; fraPart = ((fraPart * 8 + 50) / 100) & 7; block->BRR = intPart | fraPart; /* enable */ block->CR1 |= 0x2000; } void usartClose(const struct usart* __restrict usart) { struct StmUsart *block = (struct StmUsart*)mUsartPorts[usart->unit]; /* Disable USART */ block->CR1 &=~ 0x2000; /* Disable USART clock */ pwrUnitClock(mUsartBusses[usart->unit], mUsartPeriphs[usart->unit], false); /* Release gpios */ gpioRelease(usart->rx); gpioRelease(usart->tx); } void usartPutchar(const struct usart* __restrict usart, char c) { struct StmUsart *block = (struct StmUsart*)mUsartPorts[usart->unit]; /* wait for ready */ while (!(block->SR & 0x0080)); /* send */ block->DR = (uint8_t)c; }