sparc: leon3: Add debug_uart support to LEON3 serial driver.

Signed-off-by: Francois Retief <fgretief@spaceteq.co.za>

arch/sparc/cpu/leon3/cpu_init.c

@@ -13,6 +13,7 @@
 #include <ambapp.h>
 #include <grlib/irqmp.h>
 #include <grlib/gptimer.h>
+#include <debug_uart.h>
 
 #include <config.h>
 
@@ -50,7 +51,9 @@ struct {
  */
 void cpu_init_f(void)
 {
-
+#ifdef CONFIG_DEBUG_UART
+	debug_uart_init();
+#endif
 }
 
 /* Routine called from start.S,

arch/sparc/cpu/leon3/serial.c

@@ -28,8 +28,10 @@ static int leon3_serial_init(void)
 
 	/* find UART */
 	if (ambapp_apb_find(&ambapp_plb, VENDOR_GAISLER, GAISLER_APBUART,
-		CONFIG_SYS_GRLIB_APBUART_INDEX, &apbdev) != 1)
+		CONFIG_SYS_GRLIB_APBUART_INDEX, &apbdev) != 1) {
+		panic("%s: apbuart not found!\n", __func__);
 		return -1; /* didn't find hardware */
+	}
 
 	/* found apbuart, let's init .. */
 	uart = (ambapp_dev_apbuart *) apbdev.address;
@@ -145,3 +147,26 @@ __weak struct serial_device *default_serial_console(void)
 {
 	return &leon3_serial_drv;
 }
+
+#ifdef CONFIG_DEBUG_UART_APBUART
+
+#include <debug_uart.h>
+
+static inline void _debug_uart_init(void)
+{
+	ambapp_dev_apbuart *uart = (ambapp_dev_apbuart *)CONFIG_DEBUG_UART_BASE;
+	uart->scaler = (((CONFIG_DEBUG_UART_CLOCK*10) / (CONFIG_BAUDRATE*8)) - 5)/10;
+	uart->ctrl = APBUART_CTRL_RE | APBUART_CTRL_TE;
+}
+
+static inline void _debug_uart_putc(int ch)
+{
+	ambapp_dev_apbuart *uart = (ambapp_dev_apbuart *)CONFIG_DEBUG_UART_BASE;
+	while (!(readl(&uart->status) & APBUART_STATUS_THE))
+		WATCHDOG_RESET();
+	writel(ch, &uart->data);
+}
+
+DEBUG_UART_FUNCS
+
+#endif

configs/grsim_defconfig

@@ -14,3 +14,7 @@ CONFIG_SYS_TEXT_BASE=0x00000000
 # CONFIG_CMD_NET is not set
 # CONFIG_CMD_NFS is not set
 CONFIG_SYS_AMBAPP_PRINT_ON_STARTUP=y
+CONFIG_DEBUG_UART=y
+CONFIG_DEBUG_UART_APBUART=y
+CONFIG_DEBUG_UART_BASE=0x80000100
+CONFIG_DEBUG_UART_CLOCK=40000000

drivers/serial/Kconfig

@@ -98,6 +98,14 @@ config DEBUG_UART_ZYNQ
 	  will need to provide parameters to make this work. The driver will
 	  be available until the real driver-model serial is running.
 
+config DEBUG_UART_APBUART
+	depends on LEON3
+	bool "Gaisler APBUART"
+	help
+	  Select this to enable a debug UART using the serial_leon3 driver. You
+	  will need to provide parameters to make this work. The driver will
+	  be available until the real driver model serial is running.
+
 endchoice
 
 config DEBUG_UART_BASE