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/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "jtag.h"
#include "registers.h"
int jtag_pre_init(void)
{
/* Enable clocks to GPIO block C */
LM4_SYSTEM_RCGCGPIO |= 0x0004;
/* Ensure PC0:3 are set to JTAG function. They should be set this way
* on a cold boot, but on a warm reboot a previous misbehaving image
* could have set them differently. */
if (((LM4_GPIO_PCTL(LM4_GPIO_C) & 0x0000ffff) == 0x00001111) &&
((LM4_GPIO_AFSEL(LM4_GPIO_C) & 0x0f) == 0x0f) &&
((LM4_GPIO_DEN(LM4_GPIO_C) & 0x0f) == 0x0f) &&
((LM4_GPIO_PUR(LM4_GPIO_C) & 0x0f) == 0x0f))
return EC_SUCCESS; /* Already properly configured */
/* Unlock commit register for JTAG pins */
LM4_GPIO_LOCK(LM4_GPIO_C) = LM4_GPIO_LOCK_UNLOCK;
LM4_GPIO_CR(LM4_GPIO_C) |= 0x0f;
/* Reset JTAG pins */
LM4_GPIO_PCTL(LM4_GPIO_C) =
(LM4_GPIO_PCTL(LM4_GPIO_C) & 0xffff0000) | 0x00001111;
LM4_GPIO_AFSEL(LM4_GPIO_C) |= 0x0f;
LM4_GPIO_DEN(LM4_GPIO_C) |= 0x0f;
LM4_GPIO_PUR(LM4_GPIO_C) |= 0x0f;
/* Re-lock commit register */
LM4_GPIO_CR(LM4_GPIO_C) &= ~0x0f;
LM4_GPIO_LOCK(LM4_GPIO_C) = 0;
return EC_SUCCESS;
}
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