/*
* Copyright (c) 2013 Alan Cudmore
*
* 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
*
*/
#include <libchip/sersupp.h>
#include <bsp.h>
#include <bsp/irq.h>
#include <bsp/usart.h>
#include <bsp/raspberrypi.h>
static void usart_delay(uint32_t n)
{
volatile uint32_t i = 0;
for(i = 0; i < n; i++);
}
static rtems_vector_number usart_get_irq_number(const console_tbl *ct)
{
return ct->ulIntVector;
}
static uint32_t usart_get_baud(const console_tbl *ct)
{
return ct->ulClock;
}
static void usart_set_baud(int minor, int baud)
{
/*
** Nothing for now
*/
return;
}
static void usart_initialize(int minor)
{
unsigned int gpio_reg;
/*
** Program GPIO pins for UART 0
*/
gpio_reg = BCM2835_REG(BCM2835_GPIO_GPFSEL1);
gpio_reg &= ~(7<<12); /* gpio14 */
gpio_reg |= (4<<12); /* alt0 */
gpio_reg &= ~(7<<15); /* gpio15 */
gpio_reg |= (4<<15); /* alt0 */
BCM2835_REG(BCM2835_GPIO_GPFSEL1) = gpio_reg;
BCM2835_REG(BCM2835_GPIO_GPPUD) = 0;
usart_delay(150);
BCM2835_REG(BCM2835_GPIO_GPPUDCLK0) = (1<<14)|(1<<15);
usart_delay(150);
BCM2835_REG(BCM2835_GPIO_GPPUDCLK0) = 0;
/*
** Init the PL011 UART
*/
BCM2835_REG(BCM2835_UART0_CR) = 0;
BCM2835_REG(BCM2835_UART0_ICR) = 0x7FF;
BCM2835_REG(BCM2835_UART0_IMSC) = 0;
BCM2835_REG(BCM2835_UART0_IBRD) = 1;
BCM2835_REG(BCM2835_UART0_FBRD) = 40;
BCM2835_REG(BCM2835_UART0_LCRH) = 0x70;
BCM2835_REG(BCM2835_UART0_RSRECR) = 0;
BCM2835_REG(BCM2835_UART0_CR) = 0x301;
BCM2835_REG(BCM2835_UART0_IMSC) = BCM2835_UART0_IMSC_RX;
usart_set_baud(minor, 115000);
}
static int usart_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 usart_last_close(int major, int minor, void *arg)
{
return 0;
}
static int usart_read_polled(int minor)
{
if (minor == 0)
{
if(((BCM2835_REG(BCM2835_UART0_FR)) & BCM2835_UART0_FR_RXFE) == 0)
{
return((BCM2835_REG(BCM2835_UART0_DR)) & 0xFF );
}
else
{
return -1;
}
}
else
{
printk("Unknown console minor number: %d\n", minor);
return -1;
}
}
static void usart_write_polled(int minor, char c)
{
while (1)
{
if ((BCM2835_REG(BCM2835_UART0_FR) & BCM2835_UART0_FR_TXFF) == 0) break;
}
BCM2835_REG(BCM2835_UART0_DR) = c;
}
static ssize_t usart_write_support_polled(
int minor,
const char *s,
size_t n
)
{
ssize_t i = 0;
for (i = 0; i < n; ++i)
{
usart_write_polled(minor, s [i]);
}
return n;
}
static int usart_set_attributes(int minor, const struct termios *term)
{
return -1;
}
const console_fns bcm2835_usart_fns = {
.deviceProbe = libchip_serial_default_probe,
.deviceFirstOpen = usart_first_open,
.deviceLastClose = usart_last_close,
.deviceRead = usart_read_polled,
.deviceWrite = usart_write_support_polled,
.deviceInitialize = usart_initialize,
.deviceWritePolled = usart_write_polled,
.deviceSetAttributes = usart_set_attributes,
.deviceOutputUsesInterrupts = false
};