drivers/amlogic/console/aarch64/meson_console.S - filogic/atf - Gitiles

 /*
  * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */

 #include <asm_macros.S>
 #include <assert_macros.S>
 #include <console_macros.S>
 #include <drivers/amlogic/meson_console.h>

 	.globl console_meson_register
 	.globl console_meson_init
 	.globl console_meson_putc
 	.globl console_meson_getc
 	.globl console_meson_flush
 	.globl console_meson_core_putc
 	.globl console_meson_core_getc
 	.globl console_meson_core_flush

 	/* -----------------------------------------------
 	 * Hardware definitions
 	 * -----------------------------------------------
 	 */
 #define MESON_WFIFO_OFFSET			0x0
 #define MESON_RFIFO_OFFSET			0x4
 #define MESON_CONTROL_OFFSET			0x8
 #define MESON_STATUS_OFFSET			0xC
 #define MESON_MISC_OFFSET			0x10
 #define MESON_REG5_OFFSET			0x14

 #define MESON_CONTROL_CLR_ERROR_BIT		24
 #define MESON_CONTROL_RX_RESET_BIT		23
 #define MESON_CONTROL_TX_RESET_BIT		22
 #define MESON_CONTROL_RX_ENABLE_BIT		13
 #define MESON_CONTROL_TX_ENABLE_BIT		12

 #define MESON_STATUS_RX_EMPTY_BIT		20
 #define MESON_STATUS_TX_FULL_BIT		21
 #define MESON_STATUS_TX_EMPTY_BIT		22

 #define MESON_REG5_USE_XTAL_CLK_BIT		24
 #define MESON_REG5_USE_NEW_RATE_BIT		23
 #define MESON_REG5_NEW_BAUD_RATE_MASK		0x7FFFFF

 	/* -----------------------------------------------
 	 * int console_meson_register(uintptr_t base,
 	 *     uint32_t clk, uint32_t baud,
 	 *     console_t *console);
 	 * Function to initialize and register a new MESON
 	 * 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_meson_register
 	mov	x7, x30
 	mov	x6, x3
 	cbz	x6, register_fail
 	str	x0, [x6, #CONSOLE_T_BASE]

 	bl	console_meson_init
 	cbz	x0, register_fail

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

 register_fail:
 	ret	x7
 endfunc console_meson_register

 	/* -----------------------------------------------
 	 * int console_meson_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 : x0-x3
 	 * -----------------------------------------------
 	 */
 func console_meson_init
 	cmp	w0, #0
 	beq	init_fail
 	mov_imm	w3, 24000000 /* TODO: This only works with a 24 MHz clock. */
 	cmp	w1, w3
 	bne	init_fail
 	cmp	w2, #0
 	beq	init_fail
 	/* Set baud rate: value = ((clock / 3) / baudrate) - 1 */
 	mov	w3, #3
 	udiv	w3, w1, w3
 	udiv	w3, w3, w2
 	sub	w3, w3, #1
 	orr	w3, w3, #((1 << MESON_REG5_USE_XTAL_CLK_BIT) | \
 			  (1 << MESON_REG5_USE_NEW_RATE_BIT))
 	str	w3, [x0, #MESON_REG5_OFFSET]
 	/* Reset UART and clear error flag */
 	ldr	w3, [x0, #MESON_CONTROL_OFFSET]
 	orr	w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \
 			  (1 << MESON_CONTROL_RX_RESET_BIT) | \
 			  (1 << MESON_CONTROL_TX_RESET_BIT))
 	str	w3, [x0, #MESON_CONTROL_OFFSET]
 	bic	w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) | \
 			  (1 << MESON_CONTROL_RX_RESET_BIT) | \
 			  (1 << MESON_CONTROL_TX_RESET_BIT))
 	str	w3, [x0, #MESON_CONTROL_OFFSET]
 	/* Enable transfer and receive FIFO */
 	orr	w3, w3, #((1 << MESON_CONTROL_RX_ENABLE_BIT) | \
 			  (1 << MESON_CONTROL_TX_ENABLE_BIT))
 	str	w3, [x0, #MESON_CONTROL_OFFSET]
 	/* Success */
 	mov	w0, #1
 	ret
 init_fail:
 	mov	w0, wzr
 	ret
 endfunc console_meson_init

 	/* --------------------------------------------------------
 	 * int console_meson_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_meson_putc
 #if ENABLE_ASSERTIONS
 	cmp	x1, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */
 	ldr	x1, [x1, #CONSOLE_T_BASE]
 	b	console_meson_core_putc
 endfunc console_meson_putc

 	/* --------------------------------------------------------
 	 * int console_meson_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_meson_core_putc
 #if ENABLE_ASSERTIONS
 	cmp	x1, #0
 	ASM_ASSERT(ne)
 #endif
 	/* Prepend '\r' to '\n' */
 	cmp	w0, #0xA
 	b.ne	2f
 	/* Wait until the transmit FIFO isn't full */
 1:	ldr	w2, [x1, #MESON_STATUS_OFFSET]
 	tbnz	w2, #MESON_STATUS_TX_FULL_BIT, 1b
 	/* Write '\r' if needed */
 	mov	w2, #0xD
 	str	w2, [x1, #MESON_WFIFO_OFFSET]
 	/* Wait until the transmit FIFO isn't full */
 2:	ldr	w2, [x1, #MESON_STATUS_OFFSET]
 	tbnz	w2, #MESON_STATUS_TX_FULL_BIT, 2b
 	/* Write input character */
 	str	w0, [x1, #MESON_WFIFO_OFFSET]
 	ret
 endfunc console_meson_core_putc

 	/* ---------------------------------------------
 	 * int console_meson_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_meson_getc
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */
 	ldr	x0, [x0, #CONSOLE_T_BASE]
 	b	console_meson_core_getc
 endfunc console_meson_getc

 	/* ---------------------------------------------
 	 * int console_meson_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_meson_core_getc
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif
 	/* Is the receive FIFO empty? */
 	ldr	w1, [x0, #MESON_STATUS_OFFSET]
 	tbnz	w1, #MESON_STATUS_RX_EMPTY_BIT, 1f
 	/* Read one character from the RX FIFO */
 	ldr	w0, [x0, #MESON_RFIFO_OFFSET]
 	ret
 1:
 	mov	w0, #ERROR_NO_PENDING_CHAR
 	ret
 endfunc console_meson_core_getc

 	/* ---------------------------------------------
 	 * int console_meson_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_meson_flush
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif /* ENABLE_ASSERTIONS */
 	ldr	x0, [x0, #CONSOLE_T_BASE]
 	b	console_meson_core_flush
 endfunc console_meson_flush

 	/* ---------------------------------------------
 	 * int console_meson_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_meson_core_flush
 #if ENABLE_ASSERTIONS
 	cmp	x0, #0
 	ASM_ASSERT(ne)
 #endif
 	/* Wait until the transmit FIFO is empty */
 1:	ldr	w1, [x0, #MESON_STATUS_OFFSET]
 	tbz	w1, #MESON_STATUS_TX_EMPTY_BIT, 1b
 	mov	w0, #0
 	ret
 endfunc console_meson_core_flush
	/*
	* Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
	*
	* SPDX-License-Identifier: BSD-3-Clause
	*/

	#include <asm_macros.S>
	#include <assert_macros.S>
	#include <console_macros.S>
	#include <drivers/amlogic/meson_console.h>

	.globl console_meson_register
	.globl console_meson_init
	.globl console_meson_putc
	.globl console_meson_getc
	.globl console_meson_flush
	.globl console_meson_core_putc
	.globl console_meson_core_getc
	.globl console_meson_core_flush

	/* -----------------------------------------------
	* Hardware definitions
	* -----------------------------------------------
	*/
	#define MESON_WFIFO_OFFSET 0x0
	#define MESON_RFIFO_OFFSET 0x4
	#define MESON_CONTROL_OFFSET 0x8
	#define MESON_STATUS_OFFSET 0xC
	#define MESON_MISC_OFFSET 0x10
	#define MESON_REG5_OFFSET 0x14

	#define MESON_CONTROL_CLR_ERROR_BIT 24
	#define MESON_CONTROL_RX_RESET_BIT 23
	#define MESON_CONTROL_TX_RESET_BIT 22
	#define MESON_CONTROL_RX_ENABLE_BIT 13
	#define MESON_CONTROL_TX_ENABLE_BIT 12

	#define MESON_STATUS_RX_EMPTY_BIT 20
	#define MESON_STATUS_TX_FULL_BIT 21
	#define MESON_STATUS_TX_EMPTY_BIT 22

	#define MESON_REG5_USE_XTAL_CLK_BIT 24
	#define MESON_REG5_USE_NEW_RATE_BIT 23
	#define MESON_REG5_NEW_BAUD_RATE_MASK 0x7FFFFF

	/* -----------------------------------------------
	* int console_meson_register(uintptr_t base,
	* uint32_t clk, uint32_t baud,
	* console_t *console);
	* Function to initialize and register a new MESON
	* 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_meson_register
	mov x7, x30
	mov x6, x3
	cbz x6, register_fail
	str x0, [x6, #CONSOLE_T_BASE]

	bl console_meson_init
	cbz x0, register_fail

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

	register_fail:
	ret x7
	endfunc console_meson_register

	/* -----------------------------------------------
	* int console_meson_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 : x0-x3
	* -----------------------------------------------
	*/
	func console_meson_init
	cmp w0, #0
	beq init_fail
	mov_imm w3, 24000000 /* TODO: This only works with a 24 MHz clock. */
	cmp w1, w3
	bne init_fail
	cmp w2, #0
	beq init_fail
	/* Set baud rate: value = ((clock / 3) / baudrate) - 1 */
	mov w3, #3
	udiv w3, w1, w3
	udiv w3, w3, w2
	sub w3, w3, #1
	orr w3, w3, #((1 << MESON_REG5_USE_XTAL_CLK_BIT) \| \
	(1 << MESON_REG5_USE_NEW_RATE_BIT))
	str w3, [x0, #MESON_REG5_OFFSET]
	/* Reset UART and clear error flag */
	ldr w3, [x0, #MESON_CONTROL_OFFSET]
	orr w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) \| \
	(1 << MESON_CONTROL_RX_RESET_BIT) \| \
	(1 << MESON_CONTROL_TX_RESET_BIT))
	str w3, [x0, #MESON_CONTROL_OFFSET]
	bic w3, w3, #((1 << MESON_CONTROL_CLR_ERROR_BIT) \| \
	(1 << MESON_CONTROL_RX_RESET_BIT) \| \
	(1 << MESON_CONTROL_TX_RESET_BIT))
	str w3, [x0, #MESON_CONTROL_OFFSET]
	/* Enable transfer and receive FIFO */
	orr w3, w3, #((1 << MESON_CONTROL_RX_ENABLE_BIT) \| \
	(1 << MESON_CONTROL_TX_ENABLE_BIT))
	str w3, [x0, #MESON_CONTROL_OFFSET]
	/* Success */
	mov w0, #1
	ret
	init_fail:
	mov w0, wzr
	ret
	endfunc console_meson_init

	/* --------------------------------------------------------
	* int console_meson_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_meson_putc
	#if ENABLE_ASSERTIONS
	cmp x1, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */
	ldr x1, [x1, #CONSOLE_T_BASE]
	b console_meson_core_putc
	endfunc console_meson_putc

	/* --------------------------------------------------------
	* int console_meson_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_meson_core_putc
	#if ENABLE_ASSERTIONS
	cmp x1, #0
	ASM_ASSERT(ne)
	#endif
	/* Prepend '\r' to '\n' */
	cmp w0, #0xA
	b.ne 2f
	/* Wait until the transmit FIFO isn't full */
	1: ldr w2, [x1, #MESON_STATUS_OFFSET]
	tbnz w2, #MESON_STATUS_TX_FULL_BIT, 1b
	/* Write '\r' if needed */
	mov w2, #0xD
	str w2, [x1, #MESON_WFIFO_OFFSET]
	/* Wait until the transmit FIFO isn't full */
	2: ldr w2, [x1, #MESON_STATUS_OFFSET]
	tbnz w2, #MESON_STATUS_TX_FULL_BIT, 2b
	/* Write input character */
	str w0, [x1, #MESON_WFIFO_OFFSET]
	ret
	endfunc console_meson_core_putc

	/* ---------------------------------------------
	* int console_meson_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_meson_getc
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */
	ldr x0, [x0, #CONSOLE_T_BASE]
	b console_meson_core_getc
	endfunc console_meson_getc

	/* ---------------------------------------------
	* int console_meson_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_meson_core_getc
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif
	/* Is the receive FIFO empty? */
	ldr w1, [x0, #MESON_STATUS_OFFSET]
	tbnz w1, #MESON_STATUS_RX_EMPTY_BIT, 1f
	/* Read one character from the RX FIFO */
	ldr w0, [x0, #MESON_RFIFO_OFFSET]
	ret
	1:
	mov w0, #ERROR_NO_PENDING_CHAR
	ret
	endfunc console_meson_core_getc

	/* ---------------------------------------------
	* int console_meson_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_meson_flush
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif /* ENABLE_ASSERTIONS */
	ldr x0, [x0, #CONSOLE_T_BASE]
	b console_meson_core_flush
	endfunc console_meson_flush

	/* ---------------------------------------------
	* int console_meson_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_meson_core_flush
	#if ENABLE_ASSERTIONS
	cmp x0, #0
	ASM_ASSERT(ne)
	#endif
	/* Wait until the transmit FIFO is empty */
	1: ldr w1, [x0, #MESON_STATUS_OFFSET]
	tbz w1, #MESON_STATUS_TX_EMPTY_BIT, 1b
	mov w0, #0
	ret
	endfunc console_meson_core_flush