drivers/arm/pl011/aarch64/pl011_console.S - filogic/atf - Gitiles

 /*
  * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #include <arch.h>
 #include <asm_macros.S>
 #include <assert_macros.S>
 #include <console_macros.S>
 #include <drivers/arm/pl011.h>

 	/*
 	 * "core" functions are low-level implementations that don't require
 	 * writable memory and are thus safe to call in BL1 crash context.
 	 */
 	.globl console_pl011_core_init
 	.globl console_pl011_core_putc
 	.globl console_pl011_core_getc
 	.globl console_pl011_core_flush

 	.globl	console_pl011_putc
 	.globl	console_pl011_getc
 	.globl	console_pl011_flush

 	/* -----------------------------------------------
 	 * int console_pl011_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_pl011_core_init
 	/* Check the input base address */
 	cbz	x0, core_init_fail
 #if !PL011_GENERIC_UART
 	/* Check baud rate and uart clock for sanity */
 	cbz	w1, core_init_fail
 	cbz	w2, core_init_fail
 	/* Disable uart before programming */
 	ldr	w3, [x0, #UARTCR]
 	mov	w4, #PL011_UARTCR_UARTEN
 	bic	w3, w3, w4
 	str	w3, [x0, #UARTCR]
 	/* Program the baudrate */
 	/* Divisor =  (Uart clock * 4) / baudrate */
 	lsl	w1, w1, #2
 	udiv	w2, w1, w2
 	/* IBRD = Divisor >> 6 */
 	lsr	w1, w2, #6
 	/* Write the IBRD */
 	str	w1, [x0, #UARTIBRD]
 	/* FBRD = Divisor & 0x3F */
 	and	w1, w2, #0x3f
 	/* Write the FBRD */
 	str	w1, [x0, #UARTFBRD]
 	mov	w1, #PL011_LINE_CONTROL
 	str	w1, [x0, #UARTLCR_H]
 	/* Clear any pending errors */
 	str	wzr, [x0, #UARTECR]
 	/* Enable tx, rx, and uart overall */
 	mov	w1, #(PL011_UARTCR_RXE | PL011_UARTCR_TXE | PL011_UARTCR_UARTEN)
 	str	w1, [x0, #UARTCR]
 #endif
 	mov	w0, #1
 	ret
 core_init_fail:
 	mov	w0, wzr
 	ret
 endfunc console_pl011_core_init

 	.globl console_pl011_register

 	/* -----------------------------------------------
 	 * int console_pl011_register(uintptr_t baseaddr,
 	 *     uint32_t clock, uint32_t baud,
 	 *     console_t *console);
 	 * Function to initialize and register a new PL011
 	 * 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_pl011_register
 	mov	x7, x30
 	mov	x6, x3
 	cbz	x6, register_fail
 	str	x0, [x6, #CONSOLE_T_BASE]

 	bl	console_pl011_core_init
 	cbz	x0, register_fail

 	mov	x0, x6
 	mov	x30, x7
 	finish_console_register pl011 putc=1, getc=ENABLE_CONSOLE_GETC, flush=1

 register_fail:
 	ret	x7
 endfunc console_pl011_register

 	/* --------------------------------------------------------
 	 * int console_pl011_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_pl011_core_putc
 #if ENABLE_ASSERTIONS
 	cmp	x1, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */

 	/* Prepend '\r' to '\n' */
 	cmp	w0, #0xA
 	b.ne	2f
 1:
 	/* Check if the transmit FIFO is full */
 	ldr	w2, [x1, #UARTFR]
 	tbnz	w2, #PL011_UARTFR_TXFF_BIT, 1b
 	mov	w2, #0xD
 	str	w2, [x1, #UARTDR]
 2:
 	/* Check if the transmit FIFO is full */
 	ldr	w2, [x1, #UARTFR]
 	tbnz	w2, #PL011_UARTFR_TXFF_BIT, 2b
 	str	w0, [x1, #UARTDR]
 	ret
 endfunc console_pl011_core_putc

 	/* --------------------------------------------------------
 	 * int console_pl011_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_pl011_putc
 #if ENABLE_ASSERTIONS
 	cmp	x1, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */
 	ldr	x1, [x1, #CONSOLE_T_BASE]
 	b	console_pl011_core_putc
 endfunc console_pl011_putc

 	/* ---------------------------------------------
 	 * int console_pl011_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_pl011_core_getc
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */

 	/* Check if the receive FIFO is empty */
 	ldr	w1, [x0, #UARTFR]
 	tbnz	w1, #PL011_UARTFR_RXFE_BIT, no_char
 	ldr	w1, [x0, #UARTDR]
 	mov	w0, w1
 	ret
 no_char:
 	mov	w0, #ERROR_NO_PENDING_CHAR
 	ret
 endfunc console_pl011_core_getc

 	/* ---------------------------------------------
 	 * int console_pl011_getc(console_t *console)
 	 * Function to get a character from the console.
 	 * It returns the character grabbed on success
 	 * or -1 if no character is available.
 	 * In : x0 - pointer to console_t structure
 	 * Out: w0 - character if available, else -1
 	 * Clobber list : x0, x1
 	 * ---------------------------------------------
 	 */
 func console_pl011_getc
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */
 	ldr	x0, [x0, #CONSOLE_T_BASE]
 	b	console_pl011_core_getc
 endfunc console_pl011_getc

 	/* ---------------------------------------------
 	 * void console_pl011_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 : void.
 	 * Clobber list : x0, x1
 	 * ---------------------------------------------
 	 */
 func console_pl011_core_flush
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */
 1:
 	/* Loop until the transmit FIFO is empty */
 	ldr	w1, [x0, #UARTFR]
 	tbnz	w1, #PL011_UARTFR_BUSY_BIT, 1b
 	ret
 endfunc console_pl011_core_flush

 	/* ---------------------------------------------
 	 * void console_pl011_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 : void
 	 * Clobber list : x0, x1
 	 * ---------------------------------------------
 	 */
 func console_pl011_flush
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */
 	ldr	x0, [x0, #CONSOLE_T_BASE]
 	b	console_pl011_core_flush
 endfunc console_pl011_flush
	/*
	* Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
	*
	* SPDX-License-Identifier: BSD-3-Clause
	*/
	#include <arch.h>
	#include <asm_macros.S>
	#include <assert_macros.S>
	#include <console_macros.S>
	#include <drivers/arm/pl011.h>

	/*
	* "core" functions are low-level implementations that don't require
	* writable memory and are thus safe to call in BL1 crash context.
	*/
	.globl console_pl011_core_init
	.globl console_pl011_core_putc
	.globl console_pl011_core_getc
	.globl console_pl011_core_flush

	.globl console_pl011_putc
	.globl console_pl011_getc
	.globl console_pl011_flush

	/* -----------------------------------------------
	* int console_pl011_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_pl011_core_init
	/* Check the input base address */
	cbz x0, core_init_fail
	#if !PL011_GENERIC_UART
	/* Check baud rate and uart clock for sanity */
	cbz w1, core_init_fail
	cbz w2, core_init_fail
	/* Disable uart before programming */
	ldr w3, [x0, #UARTCR]
	mov w4, #PL011_UARTCR_UARTEN
	bic w3, w3, w4
	str w3, [x0, #UARTCR]
	/* Program the baudrate */
	/* Divisor = (Uart clock * 4) / baudrate */
	lsl w1, w1, #2
	udiv w2, w1, w2
	/* IBRD = Divisor >> 6 */
	lsr w1, w2, #6
	/* Write the IBRD */
	str w1, [x0, #UARTIBRD]
	/* FBRD = Divisor & 0x3F */
	and w1, w2, #0x3f
	/* Write the FBRD */
	str w1, [x0, #UARTFBRD]
	mov w1, #PL011_LINE_CONTROL
	str w1, [x0, #UARTLCR_H]
	/* Clear any pending errors */
	str wzr, [x0, #UARTECR]
	/* Enable tx, rx, and uart overall */
	mov w1, #(PL011_UARTCR_RXE \| PL011_UARTCR_TXE \| PL011_UARTCR_UARTEN)
	str w1, [x0, #UARTCR]
	#endif
	mov w0, #1
	ret
	core_init_fail:
	mov w0, wzr
	ret
	endfunc console_pl011_core_init

	.globl console_pl011_register

	/* -----------------------------------------------
	* int console_pl011_register(uintptr_t baseaddr,
	* uint32_t clock, uint32_t baud,
	* console_t *console);
	* Function to initialize and register a new PL011
	* 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_pl011_register
	mov x7, x30
	mov x6, x3
	cbz x6, register_fail
	str x0, [x6, #CONSOLE_T_BASE]

	bl console_pl011_core_init
	cbz x0, register_fail

	mov x0, x6
	mov x30, x7
	finish_console_register pl011 putc=1, getc=ENABLE_CONSOLE_GETC, flush=1

	register_fail:
	ret x7
	endfunc console_pl011_register

	/* --------------------------------------------------------
	* int console_pl011_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_pl011_core_putc
	#if ENABLE_ASSERTIONS
	cmp x1, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */

	/* Prepend '\r' to '\n' */
	cmp w0, #0xA
	b.ne 2f
	1:
	/* Check if the transmit FIFO is full */
	ldr w2, [x1, #UARTFR]
	tbnz w2, #PL011_UARTFR_TXFF_BIT, 1b
	mov w2, #0xD
	str w2, [x1, #UARTDR]
	2:
	/* Check if the transmit FIFO is full */
	ldr w2, [x1, #UARTFR]
	tbnz w2, #PL011_UARTFR_TXFF_BIT, 2b
	str w0, [x1, #UARTDR]
	ret
	endfunc console_pl011_core_putc

	/* --------------------------------------------------------
	* int console_pl011_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_pl011_putc
	#if ENABLE_ASSERTIONS
	cmp x1, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */
	ldr x1, [x1, #CONSOLE_T_BASE]
	b console_pl011_core_putc
	endfunc console_pl011_putc

	/* ---------------------------------------------
	* int console_pl011_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_pl011_core_getc
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */

	/* Check if the receive FIFO is empty */
	ldr w1, [x0, #UARTFR]
	tbnz w1, #PL011_UARTFR_RXFE_BIT, no_char
	ldr w1, [x0, #UARTDR]
	mov w0, w1
	ret
	no_char:
	mov w0, #ERROR_NO_PENDING_CHAR
	ret
	endfunc console_pl011_core_getc

	/* ---------------------------------------------
	* int console_pl011_getc(console_t *console)
	* Function to get a character from the console.
	* It returns the character grabbed on success
	* or -1 if no character is available.
	* In : x0 - pointer to console_t structure
	* Out: w0 - character if available, else -1
	* Clobber list : x0, x1
	* ---------------------------------------------
	*/
	func console_pl011_getc
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */
	ldr x0, [x0, #CONSOLE_T_BASE]
	b console_pl011_core_getc
	endfunc console_pl011_getc

	/* ---------------------------------------------
	* void console_pl011_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 : void.
	* Clobber list : x0, x1
	* ---------------------------------------------
	*/
	func console_pl011_core_flush
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */
	1:
	/* Loop until the transmit FIFO is empty */
	ldr w1, [x0, #UARTFR]
	tbnz w1, #PL011_UARTFR_BUSY_BIT, 1b
	ret
	endfunc console_pl011_core_flush

	/* ---------------------------------------------
	* void console_pl011_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 : void
	* Clobber list : x0, x1
	* ---------------------------------------------
	*/
	func console_pl011_flush
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */
	ldr x0, [x0, #CONSOLE_T_BASE]
	b console_pl011_core_flush
	endfunc console_pl011_flush