rpi3: console: Use same "clock-less" setup scheme as RPi4

In the wake of the upcoming unification of the console setup code
between RPi3 and RPi4, extend the "clock-less" setup scheme to the
RPi3. This avoid programming any clocks or baud rate registers,
which makes the port more robust against GPU firmware changes.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Change-Id: Ida83a963bb18a878997e9cbd55f8ceac6a2e1c1f

plat/rpi/common/include/rpi_shared.h

@@ -14,7 +14,7 @@
  ******************************************************************************/
 
 /* Utility functions */
-void rpi3_console_init(unsigned int base_clk_rate);
+void rpi3_console_init(void);
 void rpi3_setup_page_tables(uintptr_t total_base, size_t total_size,
 			    uintptr_t code_start, uintptr_t code_limit,
 			    uintptr_t rodata_start, uintptr_t rodata_limit

plat/rpi/common/rpi3_common.c

@@ -104,16 +104,19 @@ static const mmap_region_t plat_rpi3_mmap[] = {
  ******************************************************************************/
 static console_t rpi3_console;
 
-void rpi3_console_init(unsigned int base_clk_rate)
+void rpi3_console_init(void)
 {
 	int console_scope = CONSOLE_FLAG_BOOT;
-#if RPI3_RUNTIME_UART != -1
+	int rc;
+
+	if (RPI3_RUNTIME_UART != -1)
 		console_scope |= CONSOLE_FLAG_RUNTIME;
-#endif
-	int rc = console_16550_register(PLAT_RPI3_UART_BASE,
-					base_clk_rate,
-					PLAT_RPI3_UART_BAUDRATE,
+
+	rc = console_16550_register(PLAT_RPI_MINI_UART_BASE,
+				    0,
+				    PLAT_RPI_UART_BAUDRATE,
 				    &rpi3_console);
+
 	if (rc == 0) {
 		/*
 		 * The crash console doesn't use the multi console API, it uses

plat/rpi/rpi3/aarch64/plat_helpers.S

@@ -9,8 +9,6 @@
 #include <assert_macros.S>
 #include <platform_def.h>
 
-#include "../include/rpi_hw.h"
-
 	.globl	plat_crash_console_flush
 	.globl	plat_crash_console_init
 	.globl	plat_crash_console_putc
@@ -133,9 +131,9 @@ endfunc platform_mem_init
 	 * ---------------------------------------------
 	 */
 func plat_crash_console_init
-	mov_imm	x0, PLAT_RPI3_UART_BASE
-	mov_imm	x1, PLAT_RPI3_UART_CLK_IN_HZ
-	mov_imm	x2, PLAT_RPI3_UART_BAUDRATE
+	mov_imm	x0, PLAT_RPI_MINI_UART_BASE
+	mov	x1, xzr
+	mov	x2, xzr
 	b	console_16550_core_init
 endfunc plat_crash_console_init
 
@@ -147,7 +145,7 @@ endfunc plat_crash_console_init
 	 * ---------------------------------------------
 	 */
 func plat_crash_console_putc
-	mov_imm	x1, PLAT_RPI3_UART_BASE
+	mov_imm	x1, PLAT_RPI_MINI_UART_BASE
 	b	console_16550_core_putc
 endfunc plat_crash_console_putc
 
@@ -160,6 +158,6 @@ endfunc plat_crash_console_putc
 	 * ---------------------------------------------
 	 */
 func plat_crash_console_flush
-	mov_imm	x0, PLAT_RPI3_UART_BASE
+	mov_imm	x0, PLAT_RPI_MINI_UART_BASE
 	b	console_16550_core_flush
 endfunc plat_crash_console_flush

plat/rpi/rpi3/include/platform_def.h

@@ -249,9 +249,8 @@
 /*
  * Serial-related constants.
  */
-#define PLAT_RPI3_UART_BASE		RPI3_MINI_UART_BASE
-#define PLAT_RPI3_UART_CLK_IN_HZ	RPI3_MINI_UART_CLK_IN_HZ
-#define PLAT_RPI3_UART_BAUDRATE		ULL(115200)
+#define PLAT_RPI_MINI_UART_BASE		RPI3_MINI_UART_BASE
+#define PLAT_RPI_UART_BAUDRATE		ULL(115200)
 
 /*
  * System counter

plat/rpi/rpi3/include/rpi_hw.h

@@ -81,7 +81,6 @@
  */
 #define RPI3_IO_MINI_UART_OFFSET	ULL(0x00215040)
 #define RPI3_MINI_UART_BASE		(RPI_IO_BASE + RPI3_IO_MINI_UART_OFFSET)
-#define RPI3_MINI_UART_CLK_IN_HZ	ULL(500000000)
 
 /*
  * GPIO controller

plat/rpi/rpi3/rpi3_bl1_setup.c

@@ -35,7 +35,7 @@ void bl1_early_platform_setup(void)
 		      0x80000000);
 
 	/* Initialize the console to provide early debug support */
-	rpi3_console_init(PLAT_RPI3_UART_CLK_IN_HZ);
+	rpi3_console_init();
 
 	/* Allow BL1 to see the whole Trusted RAM */
 	bl1_tzram_layout.total_base = BL_RAM_BASE;

plat/rpi/rpi3/rpi3_bl2_setup.c

@@ -51,7 +51,7 @@ void bl2_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 	meminfo_t *mem_layout = (meminfo_t *) arg1;
 
 	/* Initialize the console to provide early debug support */
-	rpi3_console_init(PLAT_RPI3_UART_CLK_IN_HZ);
+	rpi3_console_init();
 
 	/* Enable arch timer */
 	generic_delay_timer_init();

plat/rpi/rpi3/rpi3_bl31_setup.c

@@ -72,7 +72,7 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 
 {
 	/* Initialize the console to provide early debug support */
-	rpi3_console_init(PLAT_RPI3_UART_CLK_IN_HZ);
+	rpi3_console_init();
 
 	/*
 	 * In debug builds, a special value is passed in 'arg1' to verify

plat/rpi/rpi4/aarch64/plat_helpers.S

@@ -10,8 +10,6 @@
 #include <platform_def.h>
 #include <cortex_a72.h>
 
-#include "../include/rpi_hw.h"
-
 	.globl	plat_crash_console_flush
 	.globl	plat_crash_console_init
 	.globl	plat_crash_console_putc
@@ -135,7 +133,7 @@ endfunc platform_mem_init
 	 * ---------------------------------------------
 	 */
 func plat_crash_console_init
-	mov_imm	x0, PLAT_RPI3_UART_BASE
+	mov_imm	x0, PLAT_RPI_MINI_UART_BASE
 	mov	x1, xzr
 	mov	x2, xzr
 	b	console_16550_core_init
@@ -149,7 +147,7 @@ endfunc plat_crash_console_init
 	 * ---------------------------------------------
 	 */
 func plat_crash_console_putc
-	mov_imm	x1, PLAT_RPI3_UART_BASE
+	mov_imm	x1, PLAT_RPI_MINI_UART_BASE
 	b	console_16550_core_putc
 endfunc plat_crash_console_putc
 
@@ -162,7 +160,7 @@ endfunc plat_crash_console_putc
 	 * ---------------------------------------------
 	 */
 func plat_crash_console_flush
-	mov_imm	x0, PLAT_RPI3_UART_BASE
+	mov_imm	x0, PLAT_RPI_MINI_UART_BASE
 	b	console_16550_core_flush
 endfunc plat_crash_console_flush
 

plat/rpi/rpi4/include/platform_def.h

@@ -126,8 +126,8 @@
 /*
  * Serial-related constants.
  */
-#define PLAT_RPI3_UART_BASE		RPI3_MINI_UART_BASE
-#define PLAT_RPI3_UART_BAUDRATE		ULL(115200)
+#define PLAT_RPI_MINI_UART_BASE		RPI4_MINI_UART_BASE
+#define PLAT_RPI_UART_BAUDRATE          ULL(115200)
 
 /*
  * System counter

plat/rpi/rpi4/include/rpi_hw.h

@@ -79,8 +79,8 @@
 /*
  * Serial port (called 'Mini UART' in the Broadcom documentation).
  */
-#define RPI3_IO_MINI_UART_OFFSET	ULL(0x00215040)
-#define RPI3_MINI_UART_BASE		(RPI_IO_BASE + RPI3_IO_MINI_UART_OFFSET)
+#define RPI4_IO_MINI_UART_OFFSET	ULL(0x00215040)
+#define RPI4_MINI_UART_BASE		(RPI_IO_BASE + RPI4_IO_MINI_UART_OFFSET)
 
 /*
  * GPIO controller

plat/rpi/rpi4/rpi4_bl31_setup.c

@@ -132,14 +132,8 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 	/* Early GPU firmware revisions need a little break here. */
 	ldelay(100000);
 
-	/*
-	 * Initialize the console to provide early debug support.
-	 * We rely on the GPU firmware to have initialised the UART correctly,
-	 * as the baud base clock rate differs across GPU firmware revisions.
-	 * Providing a base clock of 0 lets the 16550 UART init routine skip
-	 * the initial enablement and baud rate setup.
-	 */
-	rpi3_console_init(0);
+	/* Initialize the console to provide early debug support. */
+	rpi3_console_init();
 
 	bl33_image_ep_info.pc = plat_get_ns_image_entrypoint();
 	bl33_image_ep_info.spsr = rpi3_get_spsr_for_bl33_entry();