diff options
Diffstat (limited to 'bsps/or1k/generic_or1k/console/uart.c')
-rw-r--r-- | bsps/or1k/generic_or1k/console/uart.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/bsps/or1k/generic_or1k/console/uart.c b/bsps/or1k/generic_or1k/console/uart.c new file mode 100644 index 0000000000..6f8a49443d --- /dev/null +++ b/bsps/or1k/generic_or1k/console/uart.c @@ -0,0 +1,152 @@ +/** + * @file + * + * @ingroup generic_or1k_uart + * + * @brief UART support. + */ + +/* + * COPYRIGHT (c) 2014-2015 Hesham ALMatary <heshamelmatary@gmail.com> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE + */ + +#include <libchip/sersupp.h> +#include <bsp/generic_or1k.h> +#include <bsp.h> +#include <bsp/irq.h> +#include <bsp/uart.h> +#include <rtems/score/isr.h> + +static void uart_initialize(int minor); +static int uart_first_open(int major, int minor, void *arg); +static int uart_last_close(int major, int minor, void *arg); +static int uart_read_polled(int minor); +static ssize_t uart_write(int minor, const char *buf, size_t len); +static void uart_write_polled(int minor, char c); +static int uart_set_attributes(int minor, const struct termios *t); + +#if 0 +/* + * These will be useful when the driver supports interrupt driven IO. + */ +static rtems_vector_number uart_get_irq_number(const console_tbl *ct) +{ + return ct->ulIntVector; +} + +static uint32_t uart_get_baud(const console_tbl *ct) +{ + return ct->ulClock; +} +#endif + +static void uart_set_baud(int baud) +{ + uint16_t divisor = (OR1K_BSP_CLOCK_FREQ) / (16 * baud); + OR1K_REG(OR1K_BSP_UART_REG_LINE_CTRL) = + OR1K_BSP_UART_REG_LINE_CTRL_DLAB; + + OR1K_REG(OR1K_BSP_UART_REG_DEV_LATCH_LOW) = divisor & 0xff; + + OR1K_REG(OR1K_BSP_UART_REG_DEV_LATCH_HIGH) = + (divisor >> 8); +} + +static void uart_initialize(int minor) +{ + /* Set baud rate */ + uart_set_baud(OR1K_UART_DEFAULT_BAUD); + + /* Set data pattern configuration */ + OR1K_REG(OR1K_BSP_UART_REG_LINE_CTRL) = + OR1K_BSP_UART_REG_LINE_CTRL_WLEN8; + + /* Reset receiver and transmitter */ + OR1K_REG(OR1K_BSP_UART_REG_FIFO_CTRL) = + OR1K_BSP_UART_REG_FIFO_CTRL_ENABLE_FIFO | + OR1K_BSP_UART_REG_FIFO_CTRL_CLEAR_RCVR | + OR1K_BSP_UART_REG_FIFO_CTRL_TRIGGER_14; + + /* Disable all interrupts */ + OR1K_REG(OR1K_BSP_UART_REG_INT_ENABLE) = 0x00; + +} + +static int uart_first_open(int major, int minor, void *arg) +{ + rtems_libio_open_close_args_t *oc = (rtems_libio_open_close_args_t *) arg; + struct rtems_termios_tty *tty = (struct rtems_termios_tty *) oc->iop->data1; + const console_tbl *ct = Console_Port_Tbl [minor]; + console_data *cd = &Console_Port_Data [minor]; + + cd->termios_data = tty; + rtems_termios_set_initial_baud(tty, ct->ulClock); + + return 0; +} + +static int uart_last_close(int major, int minor, void *arg) +{ + return 0; +} + +static int uart_read_polled(int minor) +{ + unsigned char lsr; + + /* Get a character when avaiable */ + do { + lsr = OR1K_REG(OR1K_BSP_UART_REG_LINE_STATUS); + } while ((lsr & OR1K_BSP_UART_REG_LINE_STATUS_DR) + != OR1K_BSP_UART_REG_LINE_STATUS_DR); + + return OR1K_REG(OR1K_BSP_UART_REG_RX); +} + +static void uart_write_polled(int minor, char c) +{ + unsigned char lsr; + + /* Wait until there is no pending data in the transmitter FIFO (empty) */ + do { + lsr = OR1K_REG(OR1K_BSP_UART_REG_LINE_STATUS); + } while (!(lsr & OR1K_BSP_UART_REG_LINE_STATUS_THRE)); + + OR1K_REG(OR1K_BSP_UART_REG_TX) = c; +} + +static ssize_t uart_write( + int minor, + const char *s, + size_t n +) +{ + ssize_t i = 0; + + for (i = 0; i < n; ++i){ + uart_write_polled(minor, s [i]); + } + + return n; +} + +static int uart_set_attributes(int minor, const struct termios *term) +{ + return -1; +} + +const console_fns generic_or1k_uart_fns = { + .deviceProbe = libchip_serial_default_probe, + .deviceFirstOpen = uart_first_open, + .deviceLastClose = uart_last_close, + .deviceRead = uart_read_polled, + .deviceWrite = uart_write, + .deviceInitialize = uart_initialize, + .deviceWritePolled = uart_write_polled, + .deviceSetAttributes = uart_set_attributes, + .deviceOutputUsesInterrupts = false +}; |