Signed-off-by: Kamil Lulko rev13@wp.pl --- drivers/serial/Makefile | 1 + drivers/serial/serial.c | 2 + drivers/serial/serial_stm32.c | 117 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 120 insertions(+) create mode 100644 drivers/serial/serial_stm32.c
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 63b0cbf..eb935bf 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -45,6 +45,7 @@ obj-$(CONFIG_TEGRA_SERIAL) += serial_tegra.o obj-$(CONFIG_UNIPHIER_SERIAL) += serial_uniphier.o obj-$(CONFIG_OMAP_SERIAL) += serial_omap.o obj-$(CONFIG_X86_SERIAL) += serial_x86.o +obj-$(CONFIG_STM32_SERIAL) += serial_stm32.o
ifndef CONFIG_SPL_BUILD obj-$(CONFIG_USB_TTY) += usbtty.o diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c index 95c992a..9249a77 100644 --- a/drivers/serial/serial.c +++ b/drivers/serial/serial.c @@ -155,6 +155,7 @@ serial_initfunc(sa1100_serial_initialize); serial_initfunc(sandbox_serial_initialize); serial_initfunc(sconsole_serial_initialize); serial_initfunc(sh_serial_initialize); +serial_initfunc(stm32_serial_initialize); serial_initfunc(uartlite_serial_initialize); serial_initfunc(zynq_serial_initialize);
@@ -248,6 +249,7 @@ void serial_initialize(void) sandbox_serial_initialize(); sconsole_serial_initialize(); sh_serial_initialize(); + stm32_serial_initialize(); uartlite_serial_initialize(); zynq_serial_initialize();
diff --git a/drivers/serial/serial_stm32.c b/drivers/serial/serial_stm32.c new file mode 100644 index 0000000..3c80096 --- /dev/null +++ b/drivers/serial/serial_stm32.c @@ -0,0 +1,117 @@ +/* + * (C) Copyright 2015 + * Kamil Lulko, rev13@wp.pl + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <serial.h> +#include <asm/arch/stm32.h> + +#define STM32_USART1_BASE (STM32_APB2PERIPH_BASE + 0x1000) +#define RCC_APB2ENR_USART1EN (1 << 4) + +#define USART_BASE STM32_USART1_BASE +#define RCC_USART_ENABLE RCC_APB2ENR_USART1EN + +struct stm32_serial { + u32 sr; + u32 dr; + u32 brr; + u32 cr1; + u32 cr2; + u32 cr3; + u32 gtpr; +}; + +#define USART_CR1_RE (1 << 2) +#define USART_CR1_TE (1 << 3) +#define USART_CR1_UE (1 << 13) + +#define USART_SR_FLAG_RXNE (1 << 5) +#define USART_SR_FLAG_TXE (1 << 7) + +#define USART_BRR_F_MASK 0xF +#define USART_BRR_M_SHIFT 4 +#define USART_BRR_M_MASK 0xFFF0 + +DECLARE_GLOBAL_DATA_PTR; + +static void stm32_serial_setbrg(void) +{ + serial_init(); +} + +static int stm32_serial_init(void) +{ + struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; + u32 clock, int_div, frac_div, tmp; + + if ((USART_BASE & STM32_BUS_MASK) == STM32_APB1PERIPH_BASE) { + setbits_le32(&STM32_RCC->apb1enr, RCC_USART_ENABLE); + clock = clock_get(CLOCK_APB1); + } else if ((USART_BASE & STM32_BUS_MASK) == STM32_APB2PERIPH_BASE) { + setbits_le32(&STM32_RCC->apb2enr, RCC_USART_ENABLE); + clock = clock_get(CLOCK_APB2); + } else { + return -1; + } + + int_div = (25 * clock) / (4 * gd->baudrate); + tmp = ((int_div / 100) << USART_BRR_M_SHIFT) & USART_BRR_M_MASK; + frac_div = int_div - (100 * (tmp >> USART_BRR_M_SHIFT)); + tmp |= (((frac_div * 16) + 50) / 100) & USART_BRR_F_MASK; + + writel(tmp, &usart->brr); + setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE); + + return 0; +} + +static int stm32_serial_getc(void) +{ + struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; + while ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0) + ; + return readl(&usart->dr); +} + +static void stm32_serial_putc(const char c) +{ + struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; + while ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0) + ; + writel(c, &usart->dr); +} + +static int stm32_serial_tstc(void) +{ + struct stm32_serial *usart = (struct stm32_serial *)USART_BASE; + u8 ret; + + ret = readl(&usart->sr) & USART_SR_FLAG_RXNE; + return ret; +} + +static struct serial_device stm32_serial_drv = { + .name = "stm32_serial", + .start = stm32_serial_init, + .stop = NULL, + .setbrg = stm32_serial_setbrg, + .putc = stm32_serial_putc, + .puts = default_serial_puts, + .getc = stm32_serial_getc, + .tstc = stm32_serial_tstc, +}; + +void stm32_serial_initialize(void) +{ + serial_register(&stm32_serial_drv); +} + +__weak struct serial_device *default_serial_console(void) +{ + return &stm32_serial_drv; +}