[nrf52] First commit for platform support

platform/nrf52xxx/uart.c

@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2015 Eric Holland
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <stdarg.h>
+#include <reg.h>
+#include <debug.h>
+#include <stdio.h>
+#include <assert.h>
+#include <err.h>
+#include <lib/cbuf.h>
+#include <arch/arm/cm.h>
+#include <arch/ops.h>
+#include <dev/uart.h>
+#include <dev/gpio.h>
+#include <kernel/thread.h>
+#include <platform/debug.h>
+#include <platform/gpio.h>
+#include <target/debugconfig.h>
+#include <target/gpioconfig.h>
+
+#define RXBUF_SIZE 16
+
+//cbuf_t uart0_rx_buf;
+
+
+
+void uart_init_early(void)
+{
+#ifdef ENABLE_UART0
+
+#ifdef  UART0_TX_PIN
+    gpio_config(UART0_TX_PIN,GPIO_OUTPUT);
+    NRF_UART0->PSELTXD =   UART0_TX_PIN;
+#endif
+#ifdef  UART0_RX_PIN
+    gpio_config(UART0_RX_PIN,GPIO_INPUT);
+    NRF_UART0->PSELRXD =   UART0_RX_PIN;
+#endif
+
+    NRF_UART0->BAUDRATE =   UART_BAUDRATE_BAUDRATE_Baud115200   <<  UART_BAUDRATE_BAUDRATE_Pos;
+    NRF_UART0->CONFIG   =   UART_CONFIG_HWFC_Disabled << UART_CONFIG_HWFC_Pos | \
+                            UART_CONFIG_PARITY_Excluded << UART_CONFIG_PARITY_Pos;
+    NVIC_DisableIRQ(UART0_IRQn);
+    NRF_UART0->ENABLE   =   UART_ENABLE_ENABLE_Enabled << UART_ENABLE_ENABLE_Pos;
+    NRF_UART0->TXD      = 'E';
+    NRF_UART0->TASKS_STARTTX=1;
+    NRF_UART0->TASKS_STARTRX=1;
+#endif //ENABLE_UART0
+}
+
+void uart_init(void)
+{
+#ifdef ENABLE_UART0
+//    cbuf_initialize(&uart0_rx_buf, RXBUF_SIZE);
+//    NRF_UART0->INTENSET = UART_INTENSET_RXDRDY_Enabled << UART_INTENSET_RXDRDY_Pos;
+    NRF_UART0->EVENTS_RXDRDY = 0;
+//    NVIC_EnableIRQ(UART0_IRQn);
+    char c = NRF_UART0->RXD;
+    (void)c;
+#endif //ENABLE_UART0
+}
+
+void nrf52_UART0_IRQ(void)
+{
+//  char c;
+    arm_cm_irq_entry();
+    /*
+        bool resched = false;
+        while ( NRF_UART0->EVENTS_RXDRDY > 0 ) {
+            NRF_UART0->EVENTS_RXDRDY = 0;
+            c = NRF_UART0->RXD;
+            if (!cbuf_space_avail(&uart0_rx_buf)) {
+                break;
+            }
+            cbuf_write_char(&uart0_rx_buf, c, false);
+            resched = true;
+        }
+    */
+    arm_cm_irq_exit(false);
+}
+
+int uart_putc(int port, char c)
+{
+    while (NRF_UART0->EVENTS_TXDRDY == 0);
+    NRF_UART0->EVENTS_TXDRDY = 0;
+    NRF_UART0->TXD = c;
+    return 1;
+}
+
+int uart_getc(int port, bool wait)
+{
+    do {
+        if (NRF_UART0->EVENTS_RXDRDY > 0) {
+            NRF_UART0->EVENTS_RXDRDY=0;
+            return NRF_UART0->RXD;
+        }
+    } while (wait);
+    return -1;
+}
+
+void uart_flush_tx(int port) {}
+
+void uart_flush_rx(int port) {}
+
+void uart_init_port(int port, uint baud)
+{
+    // TODO - later
+    PANIC_UNIMPLEMENTED;
+}