Replace UART with that from amaranth-soc RFC

Signed-off-by: gatecat <[email protected]>

Author: gatecat

chipflow_lib/software/drivers/uart.c

@@ -1,12 +1,21 @@
 /* SPDX-License-Identifier: BSD-2-Clause */
 #include "uart.h"
 
+void uart_init(volatile uart_regs_t *uart, uint32_t divisor) {
+	uart->tx.config = 0;
+	uart->tx.phy_config = divisor & 0x00FFFFFF;
+	uart->tx.config = 1;
+	uart->rx.config = 0;
+	uart->rx.phy_config = divisor & 0x00FFFFFF;
+	uart->rx.config = 1;
+};
+
 void uart_putc(volatile uart_regs_t *uart, char c) {
 	if (c == '\n')
 		uart_putc(uart, '\r');
-	while (!uart->tx_ready)
+	while (!(uart->tx.status & 0x1))
 		;
-	uart->tx_data = c;
+	uart->tx.data = c;
 }
 
 void uart_puts(volatile uart_regs_t *uart, const char *s) {

chipflow_lib/software/drivers/uart.h

@@ -5,12 +5,20 @@
 #include <stdint.h>
 
 typedef struct __attribute__((packed, aligned(4))) {
-	uint32_t tx_data;
-	uint32_t rx_data;
-	uint32_t tx_ready;
-	uint32_t rx_avail;
+    uint8_t config;
+    uint8_t padding_0[3];
+    uint32_t phy_config;
+    uint8_t status;
+    uint8_t data;
+    uint8_t padding_1[6];
+} uart_mod_regs_t;
+
+typedef struct __attribute__((packed, aligned(4))) {
+    uart_mod_regs_t rx;
+    uart_mod_regs_t tx;
 } uart_regs_t;
 
+void uart_init(volatile uart_regs_t *uart, uint32_t divisor);
 void uart_putc(volatile uart_regs_t *uart, char c);
 void uart_puts(volatile uart_regs_t *uart, const char *s);
 void uart_puthex(volatile uart_regs_t *uart, uint32_t x);