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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:13:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:13:47 +0000 |
commit | 102b0d2daa97dae68d3eed54d8fe37a9cc38a892 (patch) | |
tree | bcf648efac40ca6139842707f0eba5a4496a6dd2 /drivers/imx/uart/imx_crash_uart.S | |
parent | Initial commit. (diff) | |
download | arm-trusted-firmware-upstream.tar.xz arm-trusted-firmware-upstream.zip |
Adding upstream version 2.8.0+dfsg.upstream/2.8.0+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/imx/uart/imx_crash_uart.S | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/imx/uart/imx_crash_uart.S b/drivers/imx/uart/imx_crash_uart.S new file mode 100644 index 0000000..aa987b3 --- /dev/null +++ b/drivers/imx/uart/imx_crash_uart.S @@ -0,0 +1,131 @@ +/* + * Copyright (c) Linaro 2018 Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ +#include <arch.h> +#include <asm_macros.S> +#include <assert_macros.S> +#include <imx_uart.h> +#include <platform_def.h> + + .globl imx_crash_uart_init + .globl imx_crash_uart_putc + + /* ----------------------------------------------- + * int imx_crash_uart_init(uintptr_t base_addr, + * unsigned int uart_clk, unsigned int baud_rate) + * Function to initialize the console without a + * C Runtime to print debug information. This + * function will be accessed by console_init and + * crash reporting. + * In: r0 - console base address + * r1 - Uart clock in Hz + * r2 - Baud rate + * Out: return 1 on success else 0 on error + * Clobber list : r1, r2, r3, r4 + * ----------------------------------------------- + */ +func imx_crash_uart_init + /* Free up r1 as a scratch reg */ + mov r4, r0 + mov r0, r1 + + /* Reset UART via CR2 */ + add r1, r4, #IMX_UART_CR2_OFFSET + movs r3, #0 + str r3, [r4, #IMX_UART_CR2_OFFSET] + + /* Wait for reset complete */ +__wait_cr2_reset: + ldr r3, [r1, #0] + ands r3, #IMX_UART_CR2_SRST + beq __wait_cr2_reset + + /* Enable UART */ + movs r3, #IMX_UART_CR1_UARTEN + mov r1, r2 + str r3, [r4, #IMX_UART_CR1_OFFSET] + + /* + * Ignore RTC/CTS - disable reset + * Magic value #16423 => + * IMX_UART_CR2_IRTS | IMX_UART_CR2_WS | IMX_UART_CR2_TXEN | IMX_UART_CR2_RXEN | IMX_UART_CR2_SRST + */ + movw r3, #16423 + str r3, [r4, #IMX_UART_CR2_OFFSET] + + /* + * No parity, autobaud detect-old, rxdmuxsel=1 (fixed i.mx7) + * Magic value => #132 + * IMX_UART_CR3_ADNIMP | IMX_UART_CR3_RXDMUXSEL + */ + movs r3, #132 + str r3, [r4, #IMX_UART_CR3_OFFSET] + + /* + * Set CTS FIFO trigger to 32 bytes bits 15:10 + * Magic value => #32768 + * FIFO trigger bitmask 100000 + * */ + mov r3, #32768 + str r3, [r4, #IMX_UART_CR4_OFFSET] + + /* + * TX/RX-thresh = 2 bytes, DCE (bit6 = 0), refclk @24MHz / 4 + * Magic value #2562 + * IMX_UART_FCR_TXTL(TX_RX_THRESH) | IMX_UART_FCR_RXTL(TX_RX_THRESH) | IMX_UART_FCR_RFDIV2 + */ + #ifdef IMX_UART_DTE + movw r3, #2626 + #else + movw r3, #2562 + #endif + str r3, [r4, #IMX_UART_FCR_OFFSET] + + /* This BIR should be set to 0x0F prior to writing the BMR */ + movs r3, #15 + str r3, [r4, #IMX_UART_BIR_OFFSET] + + /* Hard-code to 115200 @ 24 MHz */ + movs r0, #104 + str r0, [r4, #IMX_UART_BMR_OFFSET] + + /* Indicate success */ + movs r0, #1 + bx lr +endfunc imx_crash_uart_init + + /* -------------------------------------------------------- + * int imx_crash_uart_putc(int c, uintptr_t base_addr) + * Function to output a character over the console. It + * returns the character printed on success or -1 on error. + * In : r0 - character to be printed + * r1 - console base address + * Out : return -1 on error else return character. + * Clobber list : r2 + * -------------------------------------------------------- + */ +func imx_crash_uart_putc + /* Output specified character to UART shift-register */ + str r0, [r1, #IMX_UART_TXD_OFFSET] + + /* Wait for transmit IMX_UART_STAT2_OFFSET.IMX_UART_STAT2_TXDC == 1 */ +__putc_spin_ready: + ldr r2, [r1, #IMX_UART_STAT2_OFFSET] + ands r2, #IMX_UART_STAT2_TXDC + beq __putc_spin_ready + + /* Transmit complete do we need to fixup \n to \n\r */ + cmp r0, #10 + beq __putc_fixup_lf + + /* No fixup necessary - exit here */ + movs r0, #0 + bx lr + + /* Fixup \n to \n\r */ +__putc_fixup_lf: + movs r0, #13 + b imx_crash_uart_putc +endfunc imx_crash_uart_putc |