add early uart driver so we can print debug message in SPL stage
Signed-off-by: Lin Huang hl@rock-chips.com Acked-by: Simon Glass sjg@chromium.org --- Changes in v1: None Changes in v2: None Changes in v3: - pass uart base address to rk_uart_init() function Changes in v4: None Changes in v5: None Changes in v6: - Adviced by Simon: - add some comment
arch/arm/include/asm/arch-rockchip/uart.h | 44 +++++++++++++++++++++ arch/arm/mach-rockchip/Makefile | 1 + arch/arm/mach-rockchip/rk_early_print.c | 63 +++++++++++++++++++++++++++++++ 3 files changed, 108 insertions(+) create mode 100644 arch/arm/include/asm/arch-rockchip/uart.h create mode 100644 arch/arm/mach-rockchip/rk_early_print.c
diff --git a/arch/arm/include/asm/arch-rockchip/uart.h b/arch/arm/include/asm/arch-rockchip/uart.h new file mode 100644 index 0000000..ea86ce6 --- /dev/null +++ b/arch/arm/include/asm/arch-rockchip/uart.h @@ -0,0 +1,44 @@ +/* + * (C) Copyright 2015 Rockchip Electronics Co., Ltd + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __ASM_ARCH_UART_H +#define __ASM_ARCH_UART_H +struct rk_uart { + unsigned int rbr; /* Receive buffer register. */ + unsigned int ier; /* Interrupt enable register. */ + unsigned int fcr; /* FIFO control register. */ + unsigned int lcr; /* Line control register. */ + unsigned int mcr; /* Modem control register. */ + unsigned int lsr; /* Line status register. */ + unsigned int msr; /* Modem status register. */ + unsigned int scr; + unsigned int reserved1[(0x30 - 0x20) / 4]; + unsigned int srbr[(0x70 - 0x30) / 4]; + unsigned int far; + unsigned int tfr; + unsigned int rfw; + unsigned int usr; + unsigned int tfl; + unsigned int rfl; + unsigned int srr; + unsigned int srts; + unsigned int sbcr; + unsigned int sdmam; + unsigned int sfe; + unsigned int srt; + unsigned int stet; + unsigned int htx; + unsigned int dmasa; + unsigned int reserver2[(0xf4 - 0xac) / 4]; + unsigned int cpr; + unsigned int ucv; + unsigned int ctr; +}; + +void rk_uart_init(void *base); +void print_hex(unsigned int n); +void print(char *s); +#endif diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile index 902235b..a29675d 100644 --- a/arch/arm/mach-rockchip/Makefile +++ b/arch/arm/mach-rockchip/Makefile @@ -10,5 +10,6 @@ else obj-y += board.o endif obj-y += rk_timer.o +obj-y += rk_early_print.o obj-$(CONFIG_$(SPL_)ROCKCHIP_COMMON) += common.o obj-$(CONFIG_ROCKCHIP_RK3288) += rk3288/ diff --git a/arch/arm/mach-rockchip/rk_early_print.c b/arch/arm/mach-rockchip/rk_early_print.c new file mode 100644 index 0000000..a1c14b0 --- /dev/null +++ b/arch/arm/mach-rockchip/rk_early_print.c @@ -0,0 +1,63 @@ +/* + * (C) Copyright 2015 Rockchip Electronics Co., Ltd + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm/io.h> +#include <asm/arch/uart.h> +#include <common.h> + +static struct rk_uart *uart_ptr; + +static void uart_wrtie_byte(char byte) +{ + writel(byte, &uart_ptr->rbr); + while (!(readl(&uart_ptr->lsr) & 0x40)) + ; +} + +void print(char *s) +{ + while (*s) { + if (*s == '\n') + uart_wrtie_byte('\r'); + uart_wrtie_byte(*s); + s++; + } +} + +void print_hex(unsigned int n) +{ + int i; + int temp; + + uart_wrtie_byte('0'); + uart_wrtie_byte('x'); + + for (i = 8; i > 0; i--) { + temp = (n >> (i - 1) * 4) & 0x0f; + if (temp < 10) + uart_wrtie_byte((char)(temp + '0')); + else + uart_wrtie_byte((char)(temp - 10 + 'a')); + } + uart_wrtie_byte('\n'); + uart_wrtie_byte('\r'); +} + +/* + * TODO: since rk3036 only 4K sram to use in SPL, for saving space, + * we implement uart driver this way, we should convert this to use + * ns16550 driver in future, which support DEBUG_UART in the standard way + */ +void rk_uart_init(void *base) +{ + uart_ptr = (struct rk_uart *)base; + writel(0x83, &uart_ptr->lcr); + writel(0x0d, &uart_ptr->rbr); + writel(0x03, &uart_ptr->lcr); + + /* fifo enable, sfe is shadow register of FCR[0] */ + writel(0x01, &uart_ptr->sfe); +}