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Start writing USART driver of STM32.

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This commit is contained in:
NIIBE Yutaka
2017-12-14 20:34:24 +09:00
parent 69677aecd4
commit 022666402c
3 changed files with 162 additions and 33 deletions
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123
contrib/usart-stm32.c Normal file
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/*
* usart-stm32.c - USART driver for STM32F103 (USART2 and USART3)
*
* Copyright (C) 2017 g10 Code GmbH
* Author: NIIBE Yutaka <gniibe@fsij.org>
*
* This file is a part of Chopstx, a thread library for embedded.
*
* Chopstx is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Chopstx is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As additional permission under GNU GPL version 3 section 7, you may
* distribute non-source form of the Program without the copy of the
* GNU GPL normally required by section 4, provided you inform the
* receipents of GNU GPL by a written offer.
*
*/
#include <stdint.h>
#include <stdlib.h>
#include <chopstx.h>
#include <mcu/stm32.h>
struct USART {
volatile uint32_t SR;
volatile uint32_t DR;
volatile uint32_t BRR;
volatile uint32_t CR1;
volatile uint32_t CR2;
volatile uint32_t CR3;
volatile uint32_t GTPR;
};
#define USART2_BASE (APB1PERIPH_BASE + 0x4400)
#define USART3_BASE (APB1PERIPH_BASE + 0x4800)
static struct USART *const USART2 = (struct SYSCFG *)USART2_BASE;
static struct USART *const USART3 = (struct SYSCFG *)USART3_BASE;
#define USART_SR_CTS 0x0200
#define USART_SR_LBD 0x0100
#define USART_SR_TXE 0x0080
#define USART_SR_TC 0x0040
#define USART_SR_RXNE 0x0020
#define USART_SR_IDLE 0x0010
#define USART_SR_ORE 0x0008
#define USART_SR_NE 0x0004
#define USART_SR_FE 0x0002
#define USART_SR_PE 0x0001
static struct USART *
get_usart_dev (uint8_t dev_no)
{
if (dev_no == 2)
return USART2;
else if (dev_no == 3)
return USART3;
return NULL;
}
/* We assume 36MHz f_PCLK */
struct brr_setting { uint8_t baud_spec, uint16_t brr_value };
#define NUM_BAUD (sizeof (brr_table) / sizeof (struct brr_setting))
static const struct brr_setting brr_table[] = {
{ B600, (3750 << 4)},
{ B1200, (1875 << 4)},
{ B2400, ( 937 << 4)|8},
{ B9600, ( 234 << 4)|6},
{ B19200, ( 117 << 4)|3},
{ B57600, ( 39 << 4)|1},
{ B115200, ( 19 << 4)|8},
{ B230400, ( 9 << 4)|12},
{ B460800, ( 4 << 4)|14},
{ B921600, ( 2 << 4)|7},
};
void
usart_init (void)
{
RCC->APB1ENR |= ((1 << 18) | (1 << 17));
RCC->APB1RSTR = ((1 << 18) | (1 << 17));
RCC->APB1RSTR = 0;
}
/*
* CONFIG_BITS includes
* baud_rate
* char-bit size
* stop-bit
* parity
* mode: Normal, LIN, Smartcard, etc.
* flow_ctrl
*/
int
usart_config (uint8_t dev_no, uint32_t config_bits)
{
struct USART *dev = get_usart_dev (dev_no);
uint8_t baud_spec = (config & 0x3f);
int i;
for (i = 0; i < NUM_BAUD; i++)
if (brr_table[i].baud_spec == baud_spec)
break;
if (i >= NUM_BAUD)
return -1;
dev->BRR = brr_table[i].brr_value;
return 0;
}

33
contrib/usart-stm32f103.c
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@@ -1,33 +0,0 @@
/*
* usart-stm32f103.c - USART driver for STM32F103
*
* Copyright (C) 2017 g10 Code GmbH
* Author: NIIBE Yutaka <gniibe@fsij.org>
*
* This file is a part of Chopstx, a thread library for embedded.
*
* Chopstx is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Chopstx is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As additional permission under GNU GPL version 3 section 7, you may
* distribute non-source form of the Program without the copy of the
* GNU GPL normally required by section 4, provided you inform the
* receipents of GNU GPL by a written offer.
*
*/
#include <stdint.h>
#include <stdlib.h>
#include <chopstx.h>
#include <mcu/stm32.h>
#include <mcu/stm32f103.h>

39
contrib/usart.h Normal file
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#define B0 0 /* POSIX to hang up */
/* POSIX supports B75 to B300 */
#define B600 16
#define B1200 17
#define B2400 19
#define B9600 21
#define B19200 22
#define B57600 24
#define B115200 25
#define B230400 26
#define B460800 27
#define B921600 28
/* POSIX supports 5, 6. USB suppots 16 */
#define CS7 (2 << 6)
#define CS8 (3 << 6)
#define STOP0B5 (0 << 9) /* Driver only */
#define STOP1B (1 << 9) /* USB, POSIX */
#define STOP1B5 (2 << 9) /* USB */
#define STOP2B (3 << 9) /* USB, POSIX */
#define PARENB (1 << 11)
#define PARODD (2 << 11)
/* USB 0: none, 1: odd, 2: even, 3: mark, 4: space */
#define CRTSCTS (1 << 14)
/*
BAUD_BITS 6
CS_BITS 3
STOP_BITS 2
PAR_BITS 3
*/
/* USB: SET_CONTROL_LINE_STATE
DTR RTS */
/* USB: SERIAL_STATE
DSR DCD RI */