diff options
Diffstat (limited to 'c/src/lib/libcpu/arm/at91rm9200/usart/usart.c')
| -rw-r--r-- | c/src/lib/libcpu/arm/at91rm9200/usart/usart.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/c/src/lib/libcpu/arm/at91rm9200/usart/usart.c b/c/src/lib/libcpu/arm/at91rm9200/usart/usart.c new file mode 100644 index 0000000000..c26cccc1f9 --- /dev/null +++ b/c/src/lib/libcpu/arm/at91rm9200/usart/usart.c @@ -0,0 +1,274 @@ +/* + * Driver for AT91RM9200 USART ports + * + * COPYRIGHT (c) 2006-2009. + * NCB - Sistemas Embarcados Ltda. (Brazil) + * Fernando Nicodemos <fgnicodemos@terra.com.br> + * + * and + * + * COPYRIGHT (c) 1989-2009. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ +*/ + +#include <bsp.h> +#include <rtems/libio.h> +#include <termios.h> + +#include <at91rm9200.h> +#include <at91rm9200_usart.h> +#include <at91rm9200_pmc.h> +#include <rtems/bspIo.h> +#include <libchip/serial.h> +#include <libchip/sersupp.h> + +/* static function prototypes */ +static int usart_first_open(int major, int minor, void *arg); +static int usart_last_close(int major, int minor, void *arg); +static int usart_read_polled(int minor); +static int usart_write_polled_support(int minor, const char *buf, int len); +static void usart_init(int minor); +static void usart_write_polled(int minor, char c); +static int usart_set_attributes(int minor, const struct termios *t); +at91rm9200_usart_regs_t *usart_get_base(int minor); + +/* Pointers to functions for handling the UART polled. */ +console_fns usart_polling_fns = { + libchip_serial_default_probe, /* deviceProbe */ + usart_first_open, /* deviceFirstOpen */ + usart_last_close, /* deviceLastClose */ + usart_read_polled, /* deviceRead */ + usart_write_polled_support, /* deviceWrite */ + usart_init, /* deviceInitialize */ + usart_write_polled, /* deviceWritePolled */ + usart_set_attributes, /* deviceSetAttributes */ + FALSE /* TRUE if interrupt driven, FALSE if not. */ +}; + +at91rm9200_usart_regs_t *usart_get_base(int minor) +{ + console_tbl *console_entry; + at91rm9200_usart_regs_t *port; + + console_entry = BSP_get_uart_from_minor(minor); + + if (console_entry == NULL) + return 0; + + port = (at91rm9200_usart_regs_t *) console_entry->ulCtrlPort1; + //printk( "minor=%d entry=%p port=%p\n", minor, console_entry, port ); + + return port; +} + +/* + * Functions called via callbacks (i.e. the ones in uart_fns + */ + +/* + * This is called the first time each device is opened. Since + * the driver is polled, we don't have to do anything. If the driver + * were interrupt driven, we'd enable interrupts here. + */ +static int usart_first_open(int major, int minor, void *arg) +{ + at91rm9200_usart_regs_t *usart; + + usart = usart_get_base(minor); + if ( !usart ) + return -1; + + /* XXX port isn't being initialized or enabled */ + + /* XXX I hope this is enough */ + usart->cr = (US_CR_RXEN | US_CR_TXEN); + return 0; +} + +/* + * This is called the last time each device is closed. Since + * the driver is polled, we don't have to do anything. If the driver + * were interrupt driven, we'd disable interrupts here. + */ +static int usart_last_close(int major, int minor, void *arg) +{ + at91rm9200_usart_regs_t *usart; + + usart = usart_get_base(minor); + if ( !usart ) + return -1; + + return 0; +} + +/* + * Read one character from UART. + * + * return -1 if there's no data, otherwise return + * the character in lowest 8 bits of returned int. + */ +static int usart_read_polled(int minor) +{ + at91rm9200_usart_regs_t *usart; + + usart = usart_get_base(minor); + if ( !usart ) + return -1; + + /* if nothing ready return -1 */ + if ( (usart->sr & US_IER_RXBUFF) == 0 ) + return -1; + + return usart->thr; +} + + +/* + * Write character out + */ +static void usart_write_polled(int minor, char c) +{ + at91rm9200_usart_regs_t *usart; + + usart = usart_get_base(minor); + if ( !usart ) + return; + + /* delay until TX empty */ + while ( (usart->sr & US_IER_TXEMPTY) == 0 ) + ; + + usart->thr = c; +} + +/* + * Write buffer to UART + * + * return 1 on success, -1 on error + */ +static int usart_write_polled_support(int minor, const char *buf, int len) +{ + at91rm9200_usart_regs_t *usart; + int nwrite=0; + + /* + * Verify the minor number + */ + usart = usart_get_base(minor); + if ( !usart ) + return -1; + + /* + * poll each byte in the string out of the port. + */ + while (nwrite < len) { + usart_write_polled(minor, *buf++); + nwrite++; + } + + /* + * return the number of bytes written. + */ + return nwrite; + + return 1; +} + + +/* Set up the UART. */ +static void usart_init(int minor) +{ + at91rm9200_usart_regs_t *usart; + + usart = usart_get_base(minor); + if ( !usart ) + return; + +} + + +/* This is for setting baud rate, bits, etc. */ +static int usart_set_attributes(int minor, const struct termios *t) +{ + uint32_t brgr; + uint32_t mode, baud, baud_requested; + at91rm9200_usart_regs_t *usart; + + usart = usart_get_base(minor); + if ( !usart ) + return -1; + + /* Get current mode register */ + mode = usart->mr & ~(US_MR_USMODE | US_MR_USCLKS | US_MR_CHRL + | US_MR_PAR | US_MR_NBSTOP); + + /* Byte size */ + switch (t->c_cflag & CSIZE){ + case CS5: + mode |= US_MR_CHRL_5; + break; + case CS6: + mode |= US_MR_CHRL_6; + break; + case CS7: + mode |= US_MR_CHRL_7; + break; + default: + mode |= US_MR_CHRL_8; + break; + } + + /* Stop bits */ + if (t->c_cflag & CSTOPB){ + mode |= US_MR_NBSTOP_2; /* 2 stop bits */ + } else + mode |= US_MR_NBSTOP_1; /* 1 stop bits */ + + /* Parity */ + if (t->c_cflag & PARENB){ + /* Mark or Space parity */ + if (t->c_cflag & PARODD){ + mode |= US_MR_PAR_ODD; + } else + mode |= US_MR_PAR_EVEN; + } else + mode |= US_MR_PAR_NONE; + + baud_requested = t->c_cflag & CBAUD; + + /* If not, set the dbgu console baud as USART baud default */ + if (!baud_requested) + baud_requested = BSP_get_baud(); + + baud = rtems_termios_baud_to_number(baud_requested); + + brgr = (at91rm9200_get_mck() / 16) / baud; + + if (brgr > 65535){ /* BRGR is 16-bit, so switch to slower clock */ + brgr /= 8; + mode |= US_MR_USCLKS_MCK_DIV8; + } + + usart->mr = mode; + usart->brgr = brgr; +} + +/* + * The following functions are not used by TERMIOS, but other RTEMS + * functions use them instead. + */ + +/* + * Read from UART. This is used in the exit code, and can't + * rely on interrupts. + */ +int usart_poll_read(int minor) +{ + return usart_read_polled(minor); +} |