From 215c8bed126313afd8c3b978c95b35ce7252c9c7 Mon Sep 17 00:00:00 2001 From: Patrick Delaunay Date: Thu, 17 May 2018 14:50:42 +0200 Subject: [PATCH] serial: stm32: Add debug uart support Add support for early debug printf, before the availability of driver model and device tree support. Signed-off-by: Patrick Delaunay Signed-off-by: Patrice Chotard Reviewed-by: Simon Glass --- drivers/serial/Kconfig | 9 +++ drivers/serial/serial_stm32.c | 105 +++++++++++++++++++++++++++------- 2 files changed, 92 insertions(+), 22 deletions(-) diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 8777909860..2940bd05dc 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -324,6 +324,15 @@ config DEBUG_UART_MXC will need to provide parameters to make this work. The driver will be available until the real driver model serial is running. +config DEBUG_UART_STM32 + bool "STMicroelectronics STM32" + depends on STM32_SERIAL + help + Select this to enable a debug UART using the serial_stm32 driver + You will need to provide parameters to make this work. + The driver will be available until the real driver model + serial is running. + config DEBUG_UART_UNIPHIER bool "UniPhier on-chip UART" depends on ARCH_UNIPHIER diff --git a/drivers/serial/serial_stm32.c b/drivers/serial/serial_stm32.c index 6717ffaaa5..724d6f9672 100644 --- a/drivers/serial/serial_stm32.c +++ b/drivers/serial/serial_stm32.c @@ -7,19 +7,21 @@ #include #include #include -#include #include +#include +#include #include #include "serial_stm32.h" -static int stm32_serial_setbrg(struct udevice *dev, int baudrate) +static void _stm32_serial_setbrg(fdt_addr_t base, + struct stm32_uart_info *uart_info, + u32 clock_rate, + int baudrate) { - struct stm32x7_serial_platdata *plat = dev_get_platdata(dev); - bool stm32f4 = plat->uart_info->stm32f4; - fdt_addr_t base = plat->base; + bool stm32f4 = uart_info->stm32f4; u32 int_div, mantissa, fraction, oversampling; - int_div = DIV_ROUND_CLOSEST(plat->clock_rate, baudrate); + int_div = DIV_ROUND_CLOSEST(clock_rate, baudrate); if (int_div < 16) { oversampling = 8; @@ -33,6 +35,14 @@ static int stm32_serial_setbrg(struct udevice *dev, int baudrate) fraction = int_div % oversampling; writel(mantissa | fraction, base + BRR_OFFSET(stm32f4)); +} + +static int stm32_serial_setbrg(struct udevice *dev, int baudrate) +{ + struct stm32x7_serial_platdata *plat = dev_get_platdata(dev); + + _stm32_serial_setbrg(plat->base, plat->uart_info, + plat->clock_rate, baudrate); return 0; } @@ -58,11 +68,11 @@ static int stm32_serial_getc(struct udevice *dev) return readl(base + RDR_OFFSET(stm32f4)); } -static int stm32_serial_putc(struct udevice *dev, const char c) +static int _stm32_serial_putc(fdt_addr_t base, + struct stm32_uart_info *uart_info, + const char c) { - struct stm32x7_serial_platdata *plat = dev_get_platdata(dev); - bool stm32f4 = plat->uart_info->stm32f4; - fdt_addr_t base = plat->base; + bool stm32f4 = uart_info->stm32f4; if ((readl(base + ISR_OFFSET(stm32f4)) & USART_ISR_FLAG_TXE) == 0) return -EAGAIN; @@ -72,6 +82,13 @@ static int stm32_serial_putc(struct udevice *dev, const char c) return 0; } +static int stm32_serial_putc(struct udevice *dev, const char c) +{ + struct stm32x7_serial_platdata *plat = dev_get_platdata(dev); + + return _stm32_serial_putc(plat->base, plat->uart_info, c); +} + static int stm32_serial_pending(struct udevice *dev, bool input) { struct stm32x7_serial_platdata *plat = dev_get_platdata(dev); @@ -86,18 +103,28 @@ static int stm32_serial_pending(struct udevice *dev, bool input) USART_ISR_FLAG_TXE ? 0 : 1; } +static void _stm32_serial_init(fdt_addr_t base, + struct stm32_uart_info *uart_info) +{ + bool stm32f4 = uart_info->stm32f4; + u8 uart_enable_bit = uart_info->uart_enable_bit; + + /* Disable uart-> enable fifo -> enable uart */ + clrbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE | + BIT(uart_enable_bit)); + if (uart_info->has_fifo) + setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_FIFOEN); + setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE | + BIT(uart_enable_bit)); +} + static int stm32_serial_probe(struct udevice *dev) { struct stm32x7_serial_platdata *plat = dev_get_platdata(dev); struct clk clk; - fdt_addr_t base = plat->base; int ret; - bool stm32f4; - u8 uart_enable_bit; plat->uart_info = (struct stm32_uart_info *)dev_get_driver_data(dev); - stm32f4 = plat->uart_info->stm32f4; - uart_enable_bit = plat->uart_info->uart_enable_bit; ret = clk_get_by_index(dev, 0, &clk); if (ret < 0) @@ -115,13 +142,7 @@ static int stm32_serial_probe(struct udevice *dev) return plat->clock_rate; }; - /* Disable uart-> enable fifo-> enable uart */ - clrbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE | - BIT(uart_enable_bit)); - if (plat->uart_info->has_fifo) - setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_FIFOEN); - setbits_le32(base + CR1_OFFSET(stm32f4), USART_CR1_RE | USART_CR1_TE | - BIT(uart_enable_bit)); + _stm32_serial_init(plat->base, plat->uart_info); return 0; } @@ -161,3 +182,43 @@ U_BOOT_DRIVER(serial_stm32) = { .probe = stm32_serial_probe, .flags = DM_FLAG_PRE_RELOC, }; + +#ifdef CONFIG_DEBUG_UART_STM32 +#include +static inline struct stm32_uart_info *_debug_uart_info(void) +{ + struct stm32_uart_info *uart_info; + +#if defined(CONFIG_STM32F4) + uart_info = &stm32f4_info; +#elif defined(CONFIG_STM32F7) + uart_info = &stm32f7_info; +#else + uart_info = &stm32h7_info; +#endif + return uart_info; +} + +static inline void _debug_uart_init(void) +{ + fdt_addr_t base = CONFIG_DEBUG_UART_BASE; + struct stm32_uart_info *uart_info = _debug_uart_info(); + + _stm32_serial_init(base, uart_info); + _stm32_serial_setbrg(base, uart_info, + CONFIG_DEBUG_UART_CLOCK, + CONFIG_BAUDRATE); + printf("DEBUG done\n"); +} + +static inline void _debug_uart_putc(int c) +{ + fdt_addr_t base = CONFIG_DEBUG_UART_BASE; + struct stm32_uart_info *uart_info = _debug_uart_info(); + + while (_stm32_serial_putc(base, uart_info, c) == -EAGAIN) + WATCHDOG_RESET(); +} + +DEBUG_UART_FUNCS +#endif -- 2.25.1