summaryrefslogtreecommitdiffstats
path: root/c/src/lib/libbsp/arm/raspberrypi/console/usart.c
diff options
context:
space:
mode:
authorAlan Cudmore <alan.cudmore@gmail.com>2013-03-23 19:13:07 +0100
committerSebastian Huber <sebastian.huber@embedded-brains.de>2013-03-24 12:57:44 +0100
commitc32b1efa43e31bd9a8a7eae3623664d00c34d842 (patch)
treee301796d2fb132b0fab24c752072cc2a7ba6e074 /c/src/lib/libbsp/arm/raspberrypi/console/usart.c
parentlibfs: Always use geteuid() and getegid() (diff)
downloadrtems-c32b1efa43e31bd9a8a7eae3623664d00c34d842.tar.bz2
bsp/raspberrypi: New BSP
Diffstat (limited to 'c/src/lib/libbsp/arm/raspberrypi/console/usart.c')
-rw-r--r--c/src/lib/libbsp/arm/raspberrypi/console/usart.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/raspberrypi/console/usart.c b/c/src/lib/libbsp/arm/raspberrypi/console/usart.c
new file mode 100644
index 0000000000..8c64b5fca6
--- /dev/null
+++ b/c/src/lib/libbsp/arm/raspberrypi/console/usart.c
@@ -0,0 +1,160 @@
+/*
+ * 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
+};