drivers/marvell/uart/a3700_console.S - filogic/atf - Gitiles

 /*
  * Copyright (C) 2016 Marvell International Ltd.
  *
  * SPDX-License-Identifier:	BSD-3-Clause
  * https://spdx.org/licenses
  */

 #include <arch.h>
 #include <asm_macros.S>
 #include <console_macros.S>
 #include <drivers/marvell/uart/a3700_console.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_a3700_core_putc
 	.globl console_a3700_core_init
 	.globl console_a3700_core_getc
 	.globl console_a3700_core_flush

 	.globl console_a3700_putc
 	.globl console_a3700_getc
 	.globl console_a3700_flush

 	/* -----------------------------------------------
 	 * int console_a3700_core_init(unsigned long 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
 	 * Clobber list : x1, x2, x3, x4
 	 * -----------------------------------------------
 	 */
 func console_a3700_core_init
 	/* Check the input base address */
 	cbz	x0, init_fail
 	/* Check baud rate and uart clock for sanity */
 	cbz	w1, init_fail
 	cbz	w2, init_fail

 	/*
 	 * Wait for the TX (THR and TSR) to be empty. If wait for 3ms, the TX FIFO is
 	 * still not empty, TX FIFO will reset by all means.
 	 */
 	mov	w4, #30				/* max time out 30 * 100 us */
 2:
 	/* Check whether TX (THR and TSR) is empty */
 	ldr	w3, [x0, #UART_STATUS_REG]
 	and	w3, w3, #UARTLSR_TXEMPTY
 	cmp	w3, #0
 	b.ne	4f

 	/* Delay */
 	mov	w3, #60000	/* 60000 cycles of below 3 instructions on 1200 MHz CPU ~~ 100 us */
 3:
 	sub	w3, w3, #1
 	cmp	w3, #0
 	b.ne	3b

 	/* Check whether wait timeout expired */
 	sub	w4, w4, #1
 	cmp	w4, #0
 	b.ne	2b

 4:
 	/* Reset UART via North Bridge Peripheral */
 	mov_imm	x4, MVEBU_NB_RESET_REG
 	ldr	w3, [x4]
 	bic	w3, w3, #MVEBU_NB_RESET_UART_N
 	str	w3, [x4]
 	orr	w3, w3, #MVEBU_NB_RESET_UART_N
 	str	w3, [x4]

 	/* Reset FIFO */
 	mov	w3, #UART_CTRL_RXFIFO_RESET
 	orr	w3, w3, #UART_CTRL_TXFIFO_RESET
 	str	w3, [x0, #UART_CTRL_REG]

 	/* Delay */
 	mov	w3, #2000
 1:
 	sub	w3, w3, #1
 	cmp	w3, #0
 	b.ne	1b

 	/* Program the baudrate */
 	/* Divisor = Round(Uartclock / (16 * baudrate)) */
 	lsl	w2, w2, #4
 	add	w1, w1, w2, lsr #1
 	udiv	w2, w1, w2
 	and	w2, w2, #0x3ff /* clear all other bits to use default clock */

 	str	w2, [x0, #UART_BAUD_REG]/* set baud rate divisor */

 	/* Set UART to default 16X scheme */
 	mov	w3, #0
 	str	w3, [x0, #UART_POSSR_REG]

 	/* No Parity, 1 Stop */
 	mov	w3, #0
 	str	w3, [x0, #UART_CTRL_REG]

 	mov	w0, #1
 	ret
 init_fail:
 	mov	w0, #0
 	ret
 endfunc console_a3700_core_init

 	.globl console_a3700_register

 	/* -----------------------------------------------
 	 * int console_a3700_register(console_t *console,
 		uintptr_t base, uint32_t clk, uint32_t baud)
 	 * Function to initialize and register a new a3700
 	 * 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, x3, x4, x6, x7, x14
 	 * -----------------------------------------------
 	 */
 func console_a3700_register
 	mov	x7, x30
 	mov	x6, x3
 	cbz	x6, register_fail
 	str	x0, [x6, #CONSOLE_T_BASE]

 	bl	console_a3700_core_init
 	cbz	x0, register_fail

 	mov	x0, x6
 	mov	x30, x7
 	finish_console_register a3700, putc=1, getc=1, flush=1

 register_fail:
 	ret	x7
 endfunc console_a3700_register

 	/* --------------------------------------------------------
 	 * int console_a3700_core_putc(int c, unsigned int 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_a3700_core_putc
 	/* Check the input parameter */
 	cbz	x1, putc_error

 	/* Prepend '\r' to '\n' */
 	cmp	w0, #0xA
 	b.ne	2f
 	/* Check if the transmit FIFO is full */
 1:	ldr	w2, [x1, #UART_STATUS_REG]
 	and	w2, w2, #UARTLSR_TXFIFOFULL
 	cmp	w2, #UARTLSR_TXFIFOFULL
 	b.eq	1b
 	mov	w2, #0xD		/* '\r' */
 	str	w2, [x1, #UART_TX_REG]

 	/* Check if the transmit FIFO is full */
 2:	ldr	w2, [x1, #UART_STATUS_REG]
 	and	w2, w2, #UARTLSR_TXFIFOFULL
 	cmp	w2, #UARTLSR_TXFIFOFULL
 	b.eq	2b
 	str	w0, [x1, #UART_TX_REG]
 	ret
 putc_error:
 	mov	w0, #-1
 	ret
 endfunc console_a3700_core_putc

 	/* --------------------------------------------------------
 	 * int console_a3700_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_a3700_putc
 	ldr	x1, [x1, #CONSOLE_T_BASE]
 	b	console_a3700_core_putc
 endfunc console_a3700_putc

 	/* ---------------------------------------------
 	 * int console_a3700_core_getc(void)
 	 * Function to get a character from the console.
 	 * It returns the character grabbed on success
 	 * or -1 if no character is available.
 	 * In : w0 - console base address
 	 * Out : w0 - character if available, else -1
 	 * Clobber list : x0, x1
 	 * ---------------------------------------------
 	 */
 func console_a3700_core_getc
 	/* Check if there is a pending character */
 	ldr	w1, [x0, #UART_STATUS_REG]
 	and	w1, w1, #UARTLSR_RXRDY
 	cmp	w1, #UARTLSR_RXRDY
 	b.ne	getc_no_char
 	ldr	w0, [x0, #UART_RX_REG]
 	and	w0, w0, #0xff
 	ret
 getc_no_char:
 	mov	w0, #ERROR_NO_PENDING_CHAR
 	ret
 endfunc console_a3700_core_getc

 	/* ---------------------------------------------
 	 * int console_a3700_getc(console_t *console)
 	 * Function to get a character from the console.
 	 * It returns the character grabbed on success
 	 * or -1 on 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_a3700_getc
 	ldr	x0, [x0, #CONSOLE_T_BASE]
 	b	console_a3700_core_getc
 endfunc console_a3700_getc

 	/* ---------------------------------------------
 	 * void console_a3700_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_a3700_core_flush
 	/* Wait for the TX (THR and TSR) to be empty */
 1:	ldr	w1, [x0, #UART_STATUS_REG]
 	and	w1, w1, #UARTLSR_TXEMPTY
 	cmp	w1, #UARTLSR_TXEMPTY
 	b.ne	1b
 	ret
 endfunc console_a3700_core_flush

 	/* ---------------------------------------------
 	 * void console_a3700_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_a3700_flush
 	ldr	x0, [x0, #CONSOLE_T_BASE]
 	b	console_a3700_core_flush
 endfunc console_a3700_flush
	/*
	* Copyright (C) 2016 Marvell International Ltd.
	*
	* SPDX-License-Identifier: BSD-3-Clause
	* https://spdx.org/licenses
	*/

	#include <arch.h>
	#include <asm_macros.S>
	#include <console_macros.S>
	#include <drivers/marvell/uart/a3700_console.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_a3700_core_putc
	.globl console_a3700_core_init
	.globl console_a3700_core_getc
	.globl console_a3700_core_flush

	.globl console_a3700_putc
	.globl console_a3700_getc
	.globl console_a3700_flush

	/* -----------------------------------------------
	* int console_a3700_core_init(unsigned long 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
	* Clobber list : x1, x2, x3, x4
	* -----------------------------------------------
	*/
	func console_a3700_core_init
	/* Check the input base address */
	cbz x0, init_fail
	/* Check baud rate and uart clock for sanity */
	cbz w1, init_fail
	cbz w2, init_fail

	/*
	* Wait for the TX (THR and TSR) to be empty. If wait for 3ms, the TX FIFO is
	* still not empty, TX FIFO will reset by all means.
	*/
	mov w4, #30 /* max time out 30 * 100 us */
	2:
	/* Check whether TX (THR and TSR) is empty */
	ldr w3, [x0, #UART_STATUS_REG]
	and w3, w3, #UARTLSR_TXEMPTY
	cmp w3, #0
	b.ne 4f

	/* Delay */
	mov w3, #60000 /* 60000 cycles of below 3 instructions on 1200 MHz CPU ~~ 100 us */
	3:
	sub w3, w3, #1
	cmp w3, #0
	b.ne 3b

	/* Check whether wait timeout expired */
	sub w4, w4, #1
	cmp w4, #0
	b.ne 2b

	4:
	/* Reset UART via North Bridge Peripheral */
	mov_imm x4, MVEBU_NB_RESET_REG
	ldr w3, [x4]
	bic w3, w3, #MVEBU_NB_RESET_UART_N
	str w3, [x4]
	orr w3, w3, #MVEBU_NB_RESET_UART_N
	str w3, [x4]

	/* Reset FIFO */
	mov w3, #UART_CTRL_RXFIFO_RESET
	orr w3, w3, #UART_CTRL_TXFIFO_RESET
	str w3, [x0, #UART_CTRL_REG]

	/* Delay */
	mov w3, #2000
	1:
	sub w3, w3, #1
	cmp w3, #0
	b.ne 1b

	/* Program the baudrate */
	/* Divisor = Round(Uartclock / (16 * baudrate)) */
	lsl w2, w2, #4
	add w1, w1, w2, lsr #1
	udiv w2, w1, w2
	and w2, w2, #0x3ff /* clear all other bits to use default clock */

	str w2, [x0, #UART_BAUD_REG]/* set baud rate divisor */

	/* Set UART to default 16X scheme */
	mov w3, #0
	str w3, [x0, #UART_POSSR_REG]

	/* No Parity, 1 Stop */
	mov w3, #0
	str w3, [x0, #UART_CTRL_REG]

	mov w0, #1
	ret
	init_fail:
	mov w0, #0
	ret
	endfunc console_a3700_core_init

	.globl console_a3700_register

	/* -----------------------------------------------
	* int console_a3700_register(console_t *console,
	uintptr_t base, uint32_t clk, uint32_t baud)
	* Function to initialize and register a new a3700
	* 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, x3, x4, x6, x7, x14
	* -----------------------------------------------
	*/
	func console_a3700_register
	mov x7, x30
	mov x6, x3
	cbz x6, register_fail
	str x0, [x6, #CONSOLE_T_BASE]

	bl console_a3700_core_init
	cbz x0, register_fail

	mov x0, x6
	mov x30, x7
	finish_console_register a3700, putc=1, getc=1, flush=1

	register_fail:
	ret x7
	endfunc console_a3700_register

	/* --------------------------------------------------------
	* int console_a3700_core_putc(int c, unsigned int 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_a3700_core_putc
	/* Check the input parameter */
	cbz x1, putc_error

	/* Prepend '\r' to '\n' */
	cmp w0, #0xA
	b.ne 2f
	/* Check if the transmit FIFO is full */
	1: ldr w2, [x1, #UART_STATUS_REG]
	and w2, w2, #UARTLSR_TXFIFOFULL
	cmp w2, #UARTLSR_TXFIFOFULL
	b.eq 1b
	mov w2, #0xD /* '\r' */
	str w2, [x1, #UART_TX_REG]

	/* Check if the transmit FIFO is full */
	2: ldr w2, [x1, #UART_STATUS_REG]
	and w2, w2, #UARTLSR_TXFIFOFULL
	cmp w2, #UARTLSR_TXFIFOFULL
	b.eq 2b
	str w0, [x1, #UART_TX_REG]
	ret
	putc_error:
	mov w0, #-1
	ret
	endfunc console_a3700_core_putc

	/* --------------------------------------------------------
	* int console_a3700_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_a3700_putc
	ldr x1, [x1, #CONSOLE_T_BASE]
	b console_a3700_core_putc
	endfunc console_a3700_putc

	/* ---------------------------------------------
	* int console_a3700_core_getc(void)
	* Function to get a character from the console.
	* It returns the character grabbed on success
	* or -1 if no character is available.
	* In : w0 - console base address
	* Out : w0 - character if available, else -1
	* Clobber list : x0, x1
	* ---------------------------------------------
	*/
	func console_a3700_core_getc
	/* Check if there is a pending character */
	ldr w1, [x0, #UART_STATUS_REG]
	and w1, w1, #UARTLSR_RXRDY
	cmp w1, #UARTLSR_RXRDY
	b.ne getc_no_char
	ldr w0, [x0, #UART_RX_REG]
	and w0, w0, #0xff
	ret
	getc_no_char:
	mov w0, #ERROR_NO_PENDING_CHAR
	ret
	endfunc console_a3700_core_getc

	/* ---------------------------------------------
	* int console_a3700_getc(console_t *console)
	* Function to get a character from the console.
	* It returns the character grabbed on success
	* or -1 on 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_a3700_getc
	ldr x0, [x0, #CONSOLE_T_BASE]
	b console_a3700_core_getc
	endfunc console_a3700_getc

	/* ---------------------------------------------
	* void console_a3700_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_a3700_core_flush
	/* Wait for the TX (THR and TSR) to be empty */
	1: ldr w1, [x0, #UART_STATUS_REG]
	and w1, w1, #UARTLSR_TXEMPTY
	cmp w1, #UARTLSR_TXEMPTY
	b.ne 1b
	ret
	endfunc console_a3700_core_flush

	/* ---------------------------------------------
	* void console_a3700_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_a3700_flush
	ldr x0, [x0, #CONSOLE_T_BASE]
	b console_a3700_core_flush
	endfunc console_a3700_flush