1 files changed, 117 insertions, 3 deletions

diff --git a/uart.c b/uart.c
index f49c1cb..e53978b 100644
--- a/uart.c
+++ b/uart.c
@@ -9,18 +9,119 @@
  * for more details.
  */
 
+#include <stdio.h>
+#include <stdlib.h>
+
 #include "nios2sim-ng.h"
 #include "device.h"
 #include "uart.h"
 
+#define uart_printf(fmt, args...)	fprintf(stdout, fmt, ##args)
+
+struct uart {
+	struct io_register regs[UART_REG_COUNT];
+	bool has_rx_data;
+	bool has_tx_data;
+};
+
+static const uint32_t uart_valid_mask[UART_REG_COUNT] = {
+	0x000001FF,	/* rxdata */
+	0x000001FF,	/* txdata */
+	0x00001FFF,	/* status */
+	0x00001FFF,	/* control */
+	0x0000FFFF,	/* divisor */
+	0x000001FF,	/* endofpacket */
+};
+
+static const uint32_t uart_readonly_mask[UART_REG_COUNT] = {
+	0x000001FF,	/* rxdata */
+	0x00000000,	/* txdata */
+	0x00000000,	/* status */
+	0x00000000,	/* control */
+	0x00000000,	/* divisor */
+	0x00000000,	/* endofpacket */
+};
+
 static int uart_init(struct device *dev)
 {
+	struct uart *u;
+	struct io_register *regs;
+	unsigned int i;
+
+	u = malloc(sizeof(struct uart));
+	if (unlikely(u == NULL))
+		return -1;
+
+	regs = u->regs;
+	for (i = 0; i < UART_REG_COUNT; i++) {
+		io_register_init(&regs[i],
+				 UART_BASE + REG_TO_OFF(i),
+				 uart_valid_mask[i],
+				 uart_readonly_mask[i],
+				 0);
+	}
+
+	u->has_rx_data = false;
+	u->has_tx_data = false;
+
+	dev->priv = u;
+
 	return 0;
 }
 
-static bool uart_is_dev_addr(struct device *dev, uint32_t addr)
+static size_t uart_read(struct device *dev, uint32_t addr, uint8_t *data, size_t count)
 {
-	if (addr >= dev->base && addr < dev->base + dev->size)
+	struct uart *u = dev->priv;
+	struct io_register *regs = u->regs;
+	unsigned int reg;
+	uint32_t val;
+	size_t ret;
+
+	trace("count=%zu\n", count);
+
+	if (addr < dev->base || addr >= dev->base + dev->size)
+		return 0;
+
+	reg = OFF_TO_REG(addr - dev->base);
+	val = io_register_read(&regs[reg]);
+
+	if (reg == UART_RXDATA_REG) {
+		u->has_rx_data = false;
+		regs[UART_STATUS_REG].value &= ~UART_CONTROL_RRDY_MASK;
+	}
+
+	return count;
+}
+
+static size_t uart_write(struct device *dev, uint32_t addr, uint8_t *data, size_t count)
+{
+	struct uart *u = dev->priv;
+	struct io_register *regs = u->regs;
+	unsigned int reg;
+	uint32_t val;
+	size_t ret;
+
+	trace("count=%zu\n", count);
+
+	if (addr < dev->base || addr >= dev->base + dev->size)
+		return 0;
+
+
+	return count;
+}
+
+static bool uart_has_irq(struct device *dev)
+{
+	struct uart *u = dev->priv;
+	uint32_t ctrl = u->regs[UART_CONTROL_REG].value;
+	uint32_t status = u->regs[UART_STATUS_REG].value;
+
+	/* Check TX ready IRQ */
+	if ((ctrl & UART_CONTROL_TRDY_MASK) && (status & UART_STATUS_TRDY_MASK))
+		return true;
+
+	/* Check RX ready IRQ */
+	if ((ctrl & UART_CONTROL_RRDY_MASK) && (status & UART_STATUS_RRDY_MASK))
 		return true;
 
 	return false;
@@ -28,14 +129,27 @@ static bool uart_is_dev_addr(struct device *dev, uint32_t addr)
 
 static void uart_simulate(struct device *dev)
 {
+	struct uart *u = dev->priv;
+	struct io_register *regs = u->regs;
+
+	if (u->has_tx_data) {
+		regs[UART_STATUS_REG].value &= ~UART_STATUS_TRDY_MASK;
+	}
+
+	if (u->has_rx_data) {
+	}
 }
 
 struct device uart_core = {
 	.name		= "UART Core",
 	.base		= UART_BASE,
 	.size		= UART_SIZE,
+	.irq_mask	= IRQ_TO_MASK(IRQ_UART),
 
 	.init		= uart_init,
-	.is_dev_addr	= uart_is_dev_addr,
+	.is_dev_addr	= NULL,	/* use generic */
+	.read		= uart_read,
+	.write		= uart_write,
+	.has_irq	= uart_has_irq,
 	.simulate	= uart_simulate,
 };