uart: Add rounded clocking for 1 mbaud

bootloader/soc/clock.c

@@ -128,6 +128,29 @@ void clock_enable_uart(u32 idx)
 	clock_enable(&_clock_uart[idx]);
 }
 
+void clock_disable_uart(u32 idx)
+{
+	clock_disable(&_clock_uart[idx]);
+}
+
+#define UART_SRC_CLK_DIV_EN (1 << 24)
+
+int clock_uart_use_src_div(u32 idx, u32 baud)
+{
+	u32 clk_src_div = CLOCK(_clock_uart[idx].source) & 0xE0000000;
+
+	if (baud == 1000000)
+		CLOCK(_clock_uart[idx].source) = clk_src_div | UART_SRC_CLK_DIV_EN | 49;
+	else
+	{
+		CLOCK(_clock_uart[idx].source) = clk_src_div | 2;
+
+		return 1;
+	}
+
+	return 0;
+}
+
 void clock_enable_i2c(u32 idx)
 {
 	clock_enable(&_clock_i2c[idx]);

bootloader/soc/clock.h

@@ -169,6 +169,8 @@ void clock_disable(const clock_t *clk);
 /*! Clock control for specific hardware portions. */
 void clock_enable_fuse(bool enable);
 void clock_enable_uart(u32 idx);
+void clock_disable_uart(u32 idx);
+int  clock_uart_use_src_div(u32 idx, u32 baud);
 void clock_enable_i2c(u32 idx);
 void clock_disable_i2c(u32 idx);
 void clock_enable_se();

bootloader/soc/uart.c

@@ -15,6 +15,7 @@
 */
 
 #include "../soc/uart.h"
+#include "../soc/clock.h"
 #include "../soc/t210.h"
 #include "../utils/util.h"
 
@@ -28,12 +29,15 @@ void uart_init(u32 idx, u32 baud)
 	// Make sure no data is being sent.
 	uart_wait_idle(idx, UART_TX_IDLE);
 
+	// Set clock.
+	bool clk_type = clock_uart_use_src_div(idx, baud);
+
 	// Misc settings.
-	u32 rate = (8 * baud + 408000000) / (16 * baud);
+	u32 div = clk_type ? ((8 * baud + 408000000) / (16 * baud)) : 1; // DIV_ROUND_CLOSEST.
 	uart->UART_IER_DLAB = 0; // Disable interrupts.
 	uart->UART_LCR = UART_LCR_DLAB | UART_LCR_WORD_LENGTH_8; // Enable DLAB & set 8n1 mode.
-	uart->UART_THR_DLAB = (u8)rate; // Divisor latch LSB.
+	uart->UART_THR_DLAB = (u8)div; // Divisor latch LSB.
-	uart->UART_IER_DLAB = (u8)(rate >> 8); // Divisor latch MSB.
+	uart->UART_IER_DLAB = (u8)(div >> 8); // Divisor latch MSB.
 	uart->UART_LCR = UART_LCR_WORD_LENGTH_8; // Disable DLAB.
 	(void)uart->UART_SPR;
 

nyx/nyx_gui/soc/clock.c

@@ -128,6 +128,29 @@ void clock_enable_uart(u32 idx)
 	clock_enable(&_clock_uart[idx]);
 }
 
+void clock_disable_uart(u32 idx)
+{
+	clock_disable(&_clock_uart[idx]);
+}
+
+#define UART_SRC_CLK_DIV_EN (1 << 24)
+
+int clock_uart_use_src_div(u32 idx, u32 baud)
+{
+	u32 clk_src_div = CLOCK(_clock_uart[idx].source) & 0xE0000000;
+
+	if (baud == 1000000)
+		CLOCK(_clock_uart[idx].source) = clk_src_div | UART_SRC_CLK_DIV_EN | 49;
+	else
+	{
+		CLOCK(_clock_uart[idx].source) = clk_src_div | 2;
+
+		return 1;
+	}
+
+	return 0;
+}
+
 void clock_enable_i2c(u32 idx)
 {
 	clock_enable(&_clock_i2c[idx]);

nyx/nyx_gui/soc/uart.c

@@ -15,6 +15,7 @@
 */
 
 #include "../soc/uart.h"
+#include "../soc/clock.h"
 #include "../soc/t210.h"
 #include "../utils/util.h"
 
@@ -28,12 +29,15 @@ void uart_init(u32 idx, u32 baud)
 	// Make sure no data is being sent.
 	uart_wait_idle(idx, UART_TX_IDLE);
 
+	// Set clock.
+	bool clk_type = clock_uart_use_src_div(idx, baud);
+
 	// Misc settings.
-	u32 rate = (8 * baud + 408000000) / (16 * baud);
+	u32 div = clk_type ? ((8 * baud + 408000000) / (16 * baud)) : 1; // DIV_ROUND_CLOSEST.
 	uart->UART_IER_DLAB = 0; // Disable interrupts.
 	uart->UART_LCR = UART_LCR_DLAB | UART_LCR_WORD_LENGTH_8; // Enable DLAB & set 8n1 mode.
-	uart->UART_THR_DLAB = (u8)rate; // Divisor latch LSB.
+	uart->UART_THR_DLAB = (u8)div; // Divisor latch LSB.
-	uart->UART_IER_DLAB = (u8)(rate >> 8); // Divisor latch MSB.
+	uart->UART_IER_DLAB = (u8)(div >> 8); // Divisor latch MSB.
 	uart->UART_LCR = UART_LCR_WORD_LENGTH_8; // Disable DLAB.
 	(void)uart->UART_SPR;