175 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			175 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * Copyright (C) 2004-2007 ARM Limited.
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|  * Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
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|  * Copyright (C) 2015 - 2016 Xilinx, Inc, Michal Simek
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|  *
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|  * As a special exception, if other files instantiate templates or use macros
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|  * or inline functions from this file, or you compile this file and link it
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|  * with other works to produce a work based on this file, this file does not
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|  * by itself cause the resulting work to be covered by the GNU General Public
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|  * License. However the source code for this file must still be made available
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|  * in accordance with section (3) of the GNU General Public License.
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| 
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|  * This exception does not invalidate any other reasons why a work based on
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|  * this file might be covered by the GNU General Public License.
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|  */
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| 
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| #include <common.h>
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| #include <dm.h>
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| #include <serial.h>
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| 
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| #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V7A) || defined(CONFIG_CPU_V7R)
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| /*
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|  * ARMV6 & ARMV7
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|  */
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| #define DCC_RBIT	(1 << 30)
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| #define DCC_WBIT	(1 << 29)
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| 
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| #define write_dcc(x)	\
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| 		__asm__ volatile ("mcr p14, 0, %0, c0, c5, 0\n" : : "r" (x))
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| 
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| #define read_dcc(x)	\
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| 		__asm__ volatile ("mrc p14, 0, %0, c0, c5, 0\n" : "=r" (x))
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| 
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| #define status_dcc(x)	\
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| 		__asm__ volatile ("mrc p14, 0, %0, c0, c1, 0\n" : "=r" (x))
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| 
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| #elif defined(CONFIG_CPU_XSCALE)
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| /*
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|  * XSCALE
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|  */
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| #define DCC_RBIT	(1 << 31)
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| #define DCC_WBIT	(1 << 28)
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| 
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| #define write_dcc(x)	\
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| 		__asm__ volatile ("mcr p14, 0, %0, c8, c0, 0\n" : : "r" (x))
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| 
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| #define read_dcc(x)	\
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| 		__asm__ volatile ("mrc p14, 0, %0, c9, c0, 0\n" : "=r" (x))
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| 
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| #define status_dcc(x)	\
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| 		__asm__ volatile ("mrc p14, 0, %0, c14, c0, 0\n" : "=r" (x))
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| 
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| #elif defined(CONFIG_ARM64)
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| /*
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|  * ARMV8
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|  */
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| #define DCC_RBIT	(1 << 30)
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| #define DCC_WBIT	(1 << 29)
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| 
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| #define write_dcc(x)   \
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| 		__asm__ volatile ("msr dbgdtrtx_el0, %0\n" : : "r" (x))
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| 
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| #define read_dcc(x)    \
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| 		__asm__ volatile ("mrs %0, dbgdtrrx_el0\n" : "=r" (x))
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| 
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| #define status_dcc(x)  \
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| 		__asm__ volatile ("mrs %0, mdccsr_el0\n" : "=r" (x))
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| 
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| #else
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| #define DCC_RBIT	(1 << 0)
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| #define DCC_WBIT	(1 << 1)
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| 
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| #define write_dcc(x)	\
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| 		__asm__ volatile ("mcr p14, 0, %0, c1, c0, 0\n" : : "r" (x))
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| 
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| #define read_dcc(x)	\
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| 		__asm__ volatile ("mrc p14, 0, %0, c1, c0, 0\n" : "=r" (x))
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| 
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| #define status_dcc(x)	\
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| 		__asm__ volatile ("mrc p14, 0, %0, c0, c0, 0\n" : "=r" (x))
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| 
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| #endif
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| 
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| #define can_read_dcc(x)	do {	\
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| 		status_dcc(x);	\
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| 		x &= DCC_RBIT;	\
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| 		} while (0);
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| 
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| #define can_write_dcc(x) do {	\
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| 		status_dcc(x);	\
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| 		x &= DCC_WBIT;	\
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| 		x = (x == 0);	\
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| 		} while (0);
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| 
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| #define TIMEOUT_COUNT 0x4000000
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| 
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| static int arm_dcc_getc(struct udevice *dev)
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| {
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| 	int ch;
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| 	register unsigned int reg;
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| 
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| 	do {
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| 		can_read_dcc(reg);
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| 	} while (!reg);
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| 	read_dcc(ch);
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| 
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| 	return ch;
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| }
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| 
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| static int arm_dcc_putc(struct udevice *dev, char ch)
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| {
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| 	register unsigned int reg;
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| 	unsigned int timeout_count = TIMEOUT_COUNT;
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| 
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| 	while (--timeout_count) {
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| 		can_write_dcc(reg);
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| 		if (reg)
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| 			break;
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| 	}
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| 	if (timeout_count == 0)
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| 		return -EAGAIN;
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| 	else
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| 		write_dcc(ch);
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| 
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| 	return 0;
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| }
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| 
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| static int arm_dcc_pending(struct udevice *dev, bool input)
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| {
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| 	register unsigned int reg;
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| 
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| 	if (input) {
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| 		can_read_dcc(reg);
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| 	} else {
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| 		can_write_dcc(reg);
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| 	}
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| 
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| 	return reg;
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| }
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| 
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| static const struct dm_serial_ops arm_dcc_ops = {
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| 	.putc = arm_dcc_putc,
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| 	.pending = arm_dcc_pending,
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| 	.getc = arm_dcc_getc,
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| };
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| 
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| static const struct udevice_id arm_dcc_ids[] = {
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| 	{ .compatible = "arm,dcc", },
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| 	{ }
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| };
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| 
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| U_BOOT_DRIVER(serial_dcc) = {
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| 	.name	= "arm_dcc",
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| 	.id	= UCLASS_SERIAL,
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| 	.of_match = arm_dcc_ids,
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| 	.ops	= &arm_dcc_ops,
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| };
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| 
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| #ifdef CONFIG_DEBUG_UART_ARM_DCC
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| 
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| #include <debug_uart.h>
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| 
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| static inline void _debug_uart_init(void)
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| {
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| }
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| 
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| static inline void _debug_uart_putc(int ch)
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| {
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| 	arm_dcc_putc(NULL, ch);
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| }
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| 
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| DEBUG_UART_FUNCS
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| #endif
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