test_src/uart_i.c

   1 /* uart_i.c */
   2 /*
   3     This file is part of the OpenARMWare.
   4     Copyright (C) 2010 Daniel Otte (daniel.otte@rub.de)
   5
   6     This program is free software: you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation, either version 3 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include <stdint.h>
  21 #include "sysclock.h"
  22 #include "hw_regs.h"
  23 #include "hw_uart_regs.h"
  24 #include "uart_defines.h"
  25 #include "circularbytebuffer.h"
  26
  27
  28 static const
  29 uint32_t uart_base[] = { UART0_BASE, UART1_BASE, UART2_BASE };
  30
  31 static const
  32 uint32_t gpio_base[] =
  33         { GPIOA_BASE, GPIOB_BASE, GPIOC_BASE, GPIOD_BASE,
  34           GPIOE_BASE, GPIOF_BASE, GPIOG_BASE, GPIOH_BASE,
  35           GPIOJ_BASE,
  36         };
  37
  38 static const
  39 uint8_t uart_tx_gpio[] = { GPIOA, GPIOD, GPIOG };
  40 static const
  41 uint8_t uart_rx_gpio[] = { GPIOA, GPIOD, GPIOG };
  42 static const
  43 uint8_t uart_tx_pin[] = { 1, 1, 1 };
  44 static const
  45 uint8_t uart_rx_pin[] = { 0, 0, 0 };
  46 static const
  47 uint8_t uart_tx_pctl[] = {1, 5, 1};
  48 static const
  49 uint8_t uart_rx_pctl[] = {1, 5, 1};
  50 static const
  51 uint8_t uart_isr_vector[] = {5, 6, 33};
  52
  53 static const
  54 uint32_t uart_rx_buffersize[] = {128, 128, 128};
  55 static const
  56 uint32_t uart_tx_buffersize[] = {256, 256, 256};
  57
  58 static
  59 circularbytebuffer_t uart_rx_buffer[3];
  60 static
  61 circularbytebuffer_t uart_tx_buffer[3];
  62
  63
  64 static
  65 void uart_tx_isr(uint8_t uartno);
  66 static
  67 void uart_rx_isr(uint8_t uartno);
  68
  69 void uart0_isr(void){
  70
  71         if(HW_REG(UART0_BASE+UARTMIS_OFFSET)&_BV(UART_TXMIS)){
  72 //              HW_REG(uart_base[0]+UARTDR_OFFSET) = 'X';
  73                 uart_tx_isr(UART_0);
  74         }
  75         if(HW_REG(UART0_BASE+UARTMIS_OFFSET)&_BV(UART_RXMIS)){
  76                 uart_rx_isr(UART_0);
  77         }
  78 }
  79
  80 static
  81 void uart_tx_isr(uint8_t uartno){
  82         uint32_t tmp;
  83         tmp = circularbytebuffer_cnt(&(uart_tx_buffer[uartno]));
  84         while(tmp-- && (!(HW_REG(uart_base[uartno]+UARTFR_OFFSET)&_BV(UART_TXFF)))){
  85                 HW_REG(uart_base[uartno]+UARTDR_OFFSET)
  86                                 = (uint32_t)circularbytebuffer_get_fifo(&(uart_tx_buffer[uartno]));
  87         }
  88         HW_REG(uart_base[uartno]+UARTICR_OFFSET) |= _BV(UART_TXIC);
  89 }
  90
  91 static
  92 void uart_rx_isr(uint8_t uartno){
  93         uint8_t c;
  94         while(!HW_REG(uart_base[uartno]+UARTFR_OFFSET)&_BV(UART_RXFE)){
  95                 c = HW_REG(uart_base[uartno]+UARTDR_OFFSET);
  96                 circularbytebuffer_append(c, &(uart_rx_buffer[uartno]));
  97         }
  98         HW_REG(uart_base[uartno]+UARTICR_OFFSET) |= _BV(UART_RXIC);
  99 }
 100
 101 void calc_baud_values(uint32_t baudrate, uint16_t* intdivider, uint8_t* fracdivider, uint8_t* highspeed){
 102         uint32_t tmp;
 103         uint32_t uart_freq;
 104         uart_freq = sysclk_get_freq();
 105         *highspeed = (baudrate*16>uart_freq)?1:0;
 106         tmp = (uint64_t)uart_freq*128/((*highspeed?8:16)*baudrate);
 107         tmp++;
 108         tmp>>=1;
 109         *fracdivider = (uint8_t)(tmp&0x3f);
 110         *intdivider = tmp>>6;
 111 }
 112
 113 uint8_t uart_init(uint8_t uartno, uint32_t baudrate, uint8_t databits, uint8_t paraty, uint8_t stopbits){
 114         uint32_t tmp;
 115         if(databits>=5){
 116                 databits-=5;
 117         }
 118         if(uartno>UART_MAX){
 119                 return UART_ERROR_WRONG_UART;
 120         }
 121         if(databits>UART_DATABITS_8){
 122                 return UART_ERROR_WRONG_DATABITS;
 123         }
 124         if(paraty>UART_PARATY_SPACE){
 125                 return UART_ERROR_WRONG_PARATY;
 126         }
 127         if(stopbits>UART_STOPBITS_TWO){
 128                 return UART_ERROR_WRONG_STOPBITS;
 129         }
 130         if(0==circularbytebuffer_init(uart_rx_buffersize[uartno], &(uart_rx_buffer[uartno]))){
 131                 return UART_ERROR_RX_BUFFER_INIT;
 132         }
 133         if(0==circularbytebuffer_init(uart_tx_buffersize[uartno], &(uart_tx_buffer[uartno]))){
 134                 return UART_ERROR_TX_BUFFER_INIT;
 135         }
 136         /* enable clock for uart */
 137         HW_REG(SYSCTL_BASE+RCGC1_OFFSET) |= _BV(uartno);
 138         /* enable clock for gpio*/
 139         HW_REG(SYSCTL_BASE+RCGC2_OFFSET) |= _BV(uart_rx_gpio[uartno]) | _BV(uart_tx_gpio[uartno]);
 140     HW_REG(SYSCTL_BASE+RCGC2_OFFSET) |= 1;
 141
 142     HW_REG(gpio_base[uart_rx_gpio[uartno]] + GPIO_ODR_OFFSET) &= ~_BV(uart_rx_pin[uartno]); /* open drain */
 143     HW_REG(gpio_base[uart_tx_gpio[uartno]] + GPIO_ODR_OFFSET) &= ~_BV(uart_tx_pin[uartno]); /* open drain */
 144     HW_REG(gpio_base[uart_rx_gpio[uartno]] + GPIO_PUR_OFFSET) &= ~_BV(uart_rx_pin[uartno]); /* pull-up */
 145     HW_REG(gpio_base[uart_tx_gpio[uartno]] + GPIO_PUR_OFFSET) &= ~_BV(uart_tx_pin[uartno]); /* pull-up */
 146     HW_REG(gpio_base[uart_rx_gpio[uartno]] + GPIO_PDR_OFFSET) &= ~_BV(uart_rx_pin[uartno]); /* pull-down*/
 147     HW_REG(gpio_base[uart_tx_gpio[uartno]] + GPIO_PDR_OFFSET) &= ~_BV(uart_tx_pin[uartno]); /* pull-down*/
 148     HW_REG(gpio_base[uart_rx_gpio[uartno]] + GPIO_DEN_OFFSET) |=  _BV(uart_rx_pin[uartno]); /* digital enable */
 149     HW_REG(gpio_base[uart_tx_gpio[uartno]] + GPIO_DEN_OFFSET) |=  _BV(uart_tx_pin[uartno]); /* digital enable */
 150
 151         /* switch to alternate function for rx */
 152         HW_REG(gpio_base[uart_rx_gpio[uartno]]+GPIO_AFSEL_OFFSET) |= _BV(uart_rx_pin[uartno]);
 153          /* switch to alternate function for tx */
 154         HW_REG(gpio_base[uart_tx_gpio[uartno]]+GPIO_AFSEL_OFFSET) |= _BV(uart_tx_pin[uartno]);
 155         /* switch multiplexer to uart for rx */
 156         HW_REG(gpio_base[uart_rx_gpio[uartno]]+GPIO_PCTL_OFFSET) &= ~(0x0f<<(uart_rx_pin[uartno]*4));
 157         HW_REG(gpio_base[uart_rx_gpio[uartno]]+GPIO_PCTL_OFFSET) |= ((uart_rx_pctl[uartno])<<(uart_rx_pin[uartno]*4));
 158         /* switch multiplexer to uart for tx */
 159         HW_REG(gpio_base[uart_tx_gpio[uartno]]+GPIO_PCTL_OFFSET) &= ~(0x0f<<(uart_tx_pin[uartno]*4));
 160         HW_REG(gpio_base[uart_tx_gpio[uartno]]+GPIO_PCTL_OFFSET) |= ((uart_tx_pctl[uartno])<<(uart_tx_pin[uartno]*4));
 161         /* set pins to be 2mA */
 162         HW_REG(gpio_base[uart_rx_gpio[uartno]]+GPIO_DR2R_OFFSET) |= _BV(uart_rx_pin[uartno]);
 163         HW_REG(gpio_base[uart_tx_gpio[uartno]]+GPIO_DR2R_OFFSET) |= _BV(uart_tx_pin[uartno]);
 164         /* configure rx pin as input */
 165         HW_REG(gpio_base[uart_rx_gpio[uartno]]+GPIO_DIR_OFFSET) &= ~_BV(uart_rx_pin[uartno]);
 166         /* configure tx pin as output */
 167         HW_REG(gpio_base[uart_tx_gpio[uartno]]+GPIO_DIR_OFFSET) |= _BV(uart_tx_pin[uartno]);
 168
 169         /* disable uart */
 170         HW_REG(uart_base[uartno]+UARTCTL_OFFSET) &= ~_BV(UART_UARTEN);
 171         /* set baudrate parameters */
 172         uint8_t highspeed;
 173         calc_baud_values(baudrate,
 174                                  (uint16_t*)&HW_REG(uart_base[uartno]+UARTIBRD_OFFSET),
 175                                  (uint8_t*)&HW_REG(uart_base[uartno]+UARTFBRD_OFFSET),
 176                                  &highspeed);
 177         /* wait until uart is no longer busy */
 178         while(HW_REG(uart_base[uartno]+UARTFR_OFFSET)&_BV(UART_BUSY))
 179                 ;
 180         /* flush FIFOs */
 181         HW_REG(uart_base[uartno]+UARTLCRH_OFFSET) &= ~_BV(UART_FEN);
 182         /* set line parameters (bits, paraty, stopbits*/
 183         tmp = HW_REG(uart_base[uartno]+UARTLCRH_OFFSET);
 184         tmp &= ~0xff;
 185         tmp |= (paraty==UART_PARATY_MARK||paraty==UART_PARATY_SPACE)?_BV(7):0; /* set flag for mark or space paraty*/
 186         tmp |= databits<<5;
 187         tmp |= _BV(UART_FEN); /* enable FIFOs */
 188         tmp |= (stopbits==UART_STOPBITS_TWO)?_BV(3):0;
 189         tmp |= (paraty==UART_PARATY_EVEN || paraty==UART_PARATY_MARK)?_BV(2):0;
 190         tmp |= (paraty!=UART_PARATY_NONE)?_BV(1):0;
 191         HW_REG(uart_base[uartno]+UARTLCRH_OFFSET) = tmp;
 192         /* set the highspeed bit accordingly */
 193         if(highspeed){
 194                 HW_REG(uart_base[uartno]+UARTCTL_OFFSET) |= _BV(UART_HSE);
 195         } else {
 196                 HW_REG(uart_base[uartno]+UARTCTL_OFFSET) &= ~_BV(UART_HSE);
 197         }
 198         /* uart interrupt enable */
 199         HW_REG(uart_base[uartno]+UARTIM_OFFSET) |= _BV(UART_TXIM) | _BV(UART_RXIM);
 200         HW_REG(ISR_ENABLE_VECTOR+uart_isr_vector[uartno]/32) |=
 201                         _BV(uart_isr_vector[uartno]%32);
 202
 203         HW_REG(uart_base[uartno]+UARTCTL_OFFSET) |= _BV(UART_EOT);
 204         HW_REG(uart_base[uartno]+UARTFR_OFFSET) = 0;
 205         HW_REG(uart_base[uartno]+UARTCTL_OFFSET) |= _BV(UART_RXE) | _BV(UART_TXE);
 206         HW_REG(uart_base[uartno]+UARTCTL_OFFSET) |= _BV(UART_UARTEN);
 207
 208         return UART_ERROR_OK;
 209 }
 210
 211
 212 void uart_putc(uint8_t uartno, uint8_t byte){
 213         if(uartno>UART_MAX){
 214                 return;
 215         }
 216         /* wait while buffer is full */
 217         while(circularbytebuffer_cnt(&(uart_tx_buffer[uartno]))==uart_tx_buffersize[uartno]){
 218         }
 219         if(circularbytebuffer_cnt(&(uart_tx_buffer[uartno]))>0){
 220                 circularbytebuffer_append(byte, &(uart_tx_buffer[uartno]));
 221                 return;
 222         }
 223         /* if we have a full uart, append to buffer */
 224         if(HW_REG(uart_base[uartno]+UARTFR_OFFSET)&_BV(UART_TXFF)){
 225                 circularbytebuffer_append(byte, &(uart_tx_buffer[uartno]));
 226                 return;
 227         }
 228         HW_REG(uart_base[uartno]+UARTDR_OFFSET) = (uint32_t)byte;
 229 }
 230
 231 uint16_t uart_getc(uint8_t uartno){
 232         if(uartno>UART_MAX){
 233                 return 0xffff;
 234         }
 235         if(circularbytebuffer_cnt(&(uart_rx_buffer[uartno]))){
 236                 return circularbytebuffer_get_fifo(&(uart_rx_buffer[uartno]));
 237         }
 238         /* wait while the FIFO is empty */
 239         while(HW_REG(uart_base[uartno]+UARTFR_OFFSET)&_BV(UART_RXFE))
 240                 ;
 241         return (uint16_t)HW_REG(uart_base[uartno]+UARTDR_OFFSET);
 242 }
 243
 244 uint32_t uart_dataavail(uint8_t uartno){
 245         if(uartno>UART_MAX){
 246                 return 0;
 247         }
 248         /* wait while the FIFO is empty */
 249         if(circularbytebuffer_cnt(&(uart_rx_buffer[uartno]))){
 250                 return 1;
 251         }
 252         return(HW_REG(uart_base[uartno]+UARTFR_OFFSET)&_BV(UART_RXFE))?0:1;
 253 }