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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/include/debug_uart.h | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/include/debug_uart.h')
-rw-r--r-- | roms/u-boot/include/debug_uart.h | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/roms/u-boot/include/debug_uart.h b/roms/u-boot/include/debug_uart.h new file mode 100644 index 000000000..714b369e6 --- /dev/null +++ b/roms/u-boot/include/debug_uart.h @@ -0,0 +1,200 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Early debug UART support + * + * (C) Copyright 2014 Google, Inc + * Writte by Simon Glass <sjg@chromium.org> + */ + +#ifndef _DEBUG_UART_H +#define _DEBUG_UART_H + +/* + * The debug UART is intended for use very early in U-Boot to debug problems + * when an ICE or other debug mechanism is not available. + * + * To use it you should: + * - Make sure your UART supports this interface + * - Enable CONFIG_DEBUG_UART + * - Enable the CONFIG for your UART to tell it to provide this interface + * (e.g. CONFIG_DEBUG_UART_NS16550) + * - Define the required settings as needed (see below) + * - Call debug_uart_init() before use + * - Call printch() to output a character + * + * Depending on your platform it may be possible to use this UART before a + * stack is available. + * + * If your UART does not support this interface you can probably add support + * quite easily. Remember that you cannot use driver model and it is preferred + * to use no stack. + * + * You must not use this UART once driver model is working and the serial + * drivers are up and running (done in serial_init()). Otherwise the drivers + * may conflict and you will get strange output. + * + * + * To enable the debug UART in your serial driver: + * + * - #include <debug_uart.h> + * - Define _debug_uart_init(), trying to avoid using the stack + * - Define _debug_uart_putc() as static inline (avoiding stack usage) + * - Immediately afterwards, add DEBUG_UART_FUNCS to define the rest of the + * functionality (printch(), etc.) + * + * If your board needs additional init for the UART to work, enable + * CONFIG_DEBUG_UART_BOARD_INIT and write a function called + * board_debug_uart_init() to perform that init. When debug_uart_init() is + * called, the init will happen automatically. + */ + +/** + * debug_uart_init() - Set up the debug UART ready for use + * + * This sets up the UART with the correct baud rate, etc. + * + * Available CONFIG is: + * + * - CONFIG_DEBUG_UART_BASE: Base address of UART + * - CONFIG_BAUDRATE: Requested baud rate + * - CONFIG_DEBUG_UART_CLOCK: Input clock for UART + */ +void debug_uart_init(void); + +#ifdef CONFIG_DEBUG_UART_BOARD_INIT +void board_debug_uart_init(void); +#else +static inline void board_debug_uart_init(void) +{ +} +#endif + +/** + * printch() - Output a character to the debug UART + * + * @ch: Character to output + */ +void printch(int ch); + +/** + * printascii() - Output an ASCII string to the debug UART + * + * @str: String to output + */ +void printascii(const char *str); + +/** + * printhex2() - Output a 2-digit hex value + * + * @value: Value to output + */ +void printhex2(unsigned int value); + +/** + * printhex4() - Output a 4-digit hex value + * + * @value: Value to output + */ +void printhex4(unsigned int value); + +/** + * printhex8() - Output a 8-digit hex value + * + * @value: Value to output + */ +void printhex8(unsigned int value); + +/** + * printdec() - Output a decimalism value + * + * @value: Value to output + */ +void printdec(unsigned int value); + +#ifdef CONFIG_DEBUG_UART_ANNOUNCE +#define _DEBUG_UART_ANNOUNCE printascii("\n<debug_uart>\n"); +#else +#define _DEBUG_UART_ANNOUNCE +#endif + +#define serial_dout(reg, value) \ + serial_out_shift((char *)com_port + \ + ((char *)reg - (char *)com_port) * \ + (1 << CONFIG_DEBUG_UART_SHIFT), \ + CONFIG_DEBUG_UART_SHIFT, value) +#define serial_din(reg) \ + serial_in_shift((char *)com_port + \ + ((char *)reg - (char *)com_port) * \ + (1 << CONFIG_DEBUG_UART_SHIFT), \ + CONFIG_DEBUG_UART_SHIFT) + +/* + * Now define some functions - this should be inserted into the serial driver + */ +#define DEBUG_UART_FUNCS \ +\ + static inline void _printch(int ch) \ + { \ + if (ch == '\n') \ + _debug_uart_putc('\r'); \ + _debug_uart_putc(ch); \ + } \ +\ + void printch(int ch) \ + { \ + _printch(ch); \ + } \ +\ + void printascii(const char *str) \ + { \ + while (*str) \ + _printch(*str++); \ + } \ +\ + static inline void printhex1(unsigned int digit) \ + { \ + digit &= 0xf; \ + _debug_uart_putc(digit > 9 ? digit - 10 + 'a' : digit + '0'); \ + } \ +\ + static inline void printhex(unsigned int value, int digits) \ + { \ + while (digits-- > 0) \ + printhex1(value >> (4 * digits)); \ + } \ +\ + void printhex2(unsigned int value) \ + { \ + printhex(value, 2); \ + } \ +\ + void printhex4(unsigned int value) \ + { \ + printhex(value, 4); \ + } \ +\ + void printhex8(unsigned int value) \ + { \ + printhex(value, 8); \ + } \ +\ + void printdec(unsigned int value) \ + { \ + if (value > 10) { \ + printdec(value / 10); \ + value %= 10; \ + } else if (value == 10) { \ + _debug_uart_putc('1'); \ + value = 0; \ + } \ + _debug_uart_putc('0' + value); \ + } \ +\ + void debug_uart_init(void) \ + { \ + board_debug_uart_init(); \ + _debug_uart_init(); \ + _DEBUG_UART_ANNOUNCE \ + } \ + +#endif |