feat(st-uart): add AARCH64 stm32_console driver
It is an adaptation for AARCH64 of the already existing AARCH32 driver.
Change-Id: Ifabf716a6bd188d2249650a34bbec1a602bcb017
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/drivers/st/uart/aarch64/stm32_console.S b/drivers/st/uart/aarch64/stm32_console.S
new file mode 100644
index 0000000..312b35d
--- /dev/null
+++ b/drivers/st/uart/aarch64/stm32_console.S
@@ -0,0 +1,255 @@
+/*
+ * Copyright (C) 2023, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <asm_macros.S>
+#include <assert_macros.S>
+#include <console_macros.S>
+#include <drivers/st/stm32_console.h>
+#include <drivers/st/stm32_uart_regs.h>
+
+#define USART_TIMEOUT 0x1000
+
+ /*
+ * "core" functions are low-level implementations that don't require
+ * writeable memory and are thus safe to call in BL1 crash context.
+ */
+ .globl console_stm32_core_init
+ .globl console_stm32_core_putc
+ .globl console_stm32_core_getc
+ .globl console_stm32_core_flush
+
+ .globl console_stm32_putc
+ .globl console_stm32_flush
+
+
+
+ /* -----------------------------------------------------------------
+ * int console_core_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: x0 - console base address
+ * w1 - Uart clock in Hz
+ * w2 - Baud rate
+ * Out: return 1 on success else 0 on error
+ * Clobber list : x1, x2, x3, x4
+ * -----------------------------------------------
+ */
+func console_stm32_core_init
+ /* Check the input base address */
+ cbz x0, core_init_fail
+#if !defined(IMAGE_BL2)
+#if STM32MP_RECONFIGURE_CONSOLE
+ /* UART clock rate is set to 0 in BL32, skip init in that case */
+ cbz x1, 1f
+#else /* STM32MP_RECONFIGURE_CONSOLE */
+ /* Skip UART initialization if it is already enabled */
+ ldr w3, [x0, #USART_CR1]
+ tst w3, #USART_CR1_UE
+ b.ne 1f
+#endif /* STM32MP_RECONFIGURE_CONSOLE */
+#endif /* IMAGE_BL2 */
+ /* Check baud rate and uart clock for sanity */
+ cbz w1, core_init_fail
+ cbz w2, core_init_fail
+ /* Disable UART */
+ ldr w3, [x0, #USART_CR1]
+ mov w4, #USART_CR1_UE
+ bic w3, w3, w4
+ str w3, [x0, #USART_CR1]
+ /* Configure UART */
+ mov w4, #(USART_CR1_TE)
+ orr w4, w4, #(USART_CR1_FIFOEN)
+ orr w3, w3, w4
+ str w3, [x0, #USART_CR1]
+ ldr w3, [x0, #USART_CR2]
+ mov w4, #USART_CR2_STOP
+ bic w3, w3, w4
+ str w3, [x0, #USART_CR2]
+ /* Divisor = (Uart clock + (baudrate / 2)) / baudrate */
+ lsr w3, w2, #1
+ add w3, w1, w3
+ udiv w3, w3, w2
+ cmp w3, #16
+ b.hi 2f
+ /* Oversampling 8 */
+ /* Divisor = (2 * Uart clock + (baudrate / 2)) / baudrate */
+ lsr w3, w2, #1
+ add w3, w3, w1, lsl #1
+ udiv w3, w3, w2
+ and w1, w3, #USART_BRR_DIV_FRACTION
+ lsr w1, w1, #1
+ bic w3, w3, #USART_BRR_DIV_FRACTION
+ orr w3, w3, w1
+ ldr w1, [x0, #USART_CR1]
+ orr w1, w1, #USART_CR1_OVER8
+ str w1, [x0, #USART_CR1]
+2:
+ str w3, [x0, #USART_BRR]
+ /* Enable UART */
+ ldr w3, [x0, #USART_CR1]
+ mov w4, #USART_CR1_UE
+ orr w3, w3, w4
+ str w3, [x0, #USART_CR1]
+ /* Check TEACK bit */
+ mov w2, #USART_TIMEOUT
+teack_loop:
+ subs w2, w2, #1
+ beq core_init_fail
+ ldr w3, [x0, #USART_ISR]
+ tst w3, #USART_ISR_TEACK
+ beq teack_loop
+1:
+ mov w0, #1
+ ret
+core_init_fail:
+ mov w0, wzr
+ ret
+endfunc console_stm32_core_init
+
+ .globl console_stm32_register
+
+ /* -------------------------------------------------------
+ * int console_stm32_register(uintptr_t baseaddr,
+ * uint32_t clock, uint32_t baud,
+ * console_t *console);
+ * Function to initialize and register a new STM32
+ * console. Storage passed in for the console struct
+ * *must* be persistent (i.e. not from the stack).
+ * In: x0 - UART register base address
+ * w1 - UART clock in Hz
+ * w2 - Baud rate
+ * x3 - pointer to empty console_t struct
+ * Out: return 1 on success, 0 on error
+ * Clobber list : x0, x1, x2, x6, x7, x14
+ * -------------------------------------------------------
+ */
+func console_stm32_register
+ mov x7, x30
+ mov x6, x3
+ cbz x6, register_fail
+ str x0, [x6, #CONSOLE_T_BASE]
+
+ bl console_stm32_core_init
+ cbz x0, register_fail
+
+ mov x0, x6
+ mov x30, x7
+ finish_console_register stm32 putc=1, getc=0, flush=1
+
+register_fail:
+ ret x7
+endfunc console_stm32_register
+
+ /* --------------------------------------------------------
+ * int console_stm32_core_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 : w0 - character to be printed
+ * x1 - console base address
+ * Out : return -1 on error else return character.
+ * Clobber list : x2
+ * --------------------------------------------------------
+ */
+func console_stm32_core_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+
+ /* Check Transmit Data Register Empty */
+txe_loop:
+ ldr w2, [x1, #USART_ISR]
+ tst w2, #USART_ISR_TXE
+ beq txe_loop
+ str w0, [x1, #USART_TDR]
+ /* Check transmit complete flag */
+tc_loop:
+ ldr w2, [x1, #USART_ISR]
+ tst w2, #USART_ISR_TC
+ beq tc_loop
+ ret
+endfunc console_stm32_core_putc
+
+ /* --------------------------------------------------------
+ * int console_stm32_putc(int c, console_t *console)
+ * Function to output a character over the console. It
+ * returns the character printed on success or -1 on error.
+ * In : w0 - character to be printed
+ * x1 - pointer to console_t structure
+ * Out : return -1 on error else return character.
+ * Clobber list : x2
+ * --------------------------------------------------------
+ */
+func console_stm32_putc
+#if ENABLE_ASSERTIONS
+ cmp x1, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x1, [x1, #CONSOLE_T_BASE]
+ b console_stm32_core_putc
+endfunc console_stm32_putc
+
+ /* ---------------------------------------------
+ * int console_stm32_core_getc(uintptr_t base_addr)
+ * Function to get a character from the console.
+ * It returns the character grabbed on success
+ * or -1 if no character is available.
+ * In : x0 - console base address
+ * Out: w0 - character if available, else -1
+ * Clobber list : x0, x1
+ * ---------------------------------------------
+ */
+func console_stm32_core_getc
+ /* Not supported */
+ mov w0, #-1
+ ret
+endfunc console_stm32_core_getc
+
+ /* ---------------------------------------------
+ * int console_stm32_core_flush(uintptr_t base_addr)
+ * Function to force a write of all buffered
+ * data that hasn't been output.
+ * In : x0 - console base address
+ * Out : return -1 on error else return 0.
+ * Clobber list : x0, x1
+ * ---------------------------------------------
+ */
+func console_stm32_core_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ /* Check Transmit Data Register Empty */
+txe_loop_3:
+ ldr w1, [x0, #USART_ISR]
+ tst w1, #USART_ISR_TXE
+ beq txe_loop_3
+ mov w0, #0
+ ret
+endfunc console_stm32_core_flush
+
+ /* ---------------------------------------------
+ * int console_stm32_flush(console_t *console)
+ * Function to force a write of all buffered
+ * data that hasn't been output.
+ * In : x0 - pointer to console_t structure
+ * Out : return -1 on error else return 0.
+ * Clobber list : x0, x1
+ * ---------------------------------------------
+ */
+func console_stm32_flush
+#if ENABLE_ASSERTIONS
+ cmp x0, #0
+ ASM_ASSERT(ne)
+#endif /* ENABLE_ASSERTIONS */
+ ldr x0, [x0, #CONSOLE_T_BASE]
+ b console_stm32_core_flush
+endfunc console_stm32_flush