99 lines
3.2 KiB
C
99 lines
3.2 KiB
C
|
/*
|
||
|
|
* OMAP IP block custom reset and preprogramming stubs
|
||
|
|
*
|
||
|
|
* Copyright (C) 2012 Texas Instruments, Inc.
|
||
|
|
* Paul Walmsley
|
||
|
|
*
|
||
|
|
* A small number of IP blocks need custom reset and preprogramming
|
||
|
|
* functions. The stubs in this file provide a standard way for the
|
||
|
|
* hwmod code to call these functions, which are to be located under
|
||
|
|
* drivers/.
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU General Public License as
|
||
|
|
* published by the Free Software Foundation version 2.
|
||
|
|
*
|
||
|
|
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
|
||
|
|
* kind, whether express or implied; without even the implied warranty
|
||
|
|
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with this program; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
|
||
|
|
* 02110-1301 USA
|
||
|
|
*/
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/errno.h>
|
||
|
|
|
||
|
|
#include "omap_hwmod.h"
|
||
|
|
#include "common.h"
|
||
|
|
|
||
|
|
#define OMAP_RTC_STATUS_REG 0x44
|
||
|
|
#define OMAP_RTC_KICK0_REG 0x6c
|
||
|
|
#define OMAP_RTC_KICK1_REG 0x70
|
||
|
|
|
||
|
|
#define OMAP_RTC_KICK0_VALUE 0x83E70B13
|
||
|
|
#define OMAP_RTC_KICK1_VALUE 0x95A4F1E0
|
||
|
|
#define OMAP_RTC_STATUS_BUSY BIT(0)
|
||
|
|
#define OMAP_RTC_MAX_READY_TIME 50
|
||
|
|
|
||
|
|
/**
|
||
|
|
* omap_rtc_wait_not_busy - Wait for the RTC BUSY flag
|
||
|
|
* @oh: struct omap_hwmod *
|
||
|
|
*
|
||
|
|
* For updating certain RTC registers, the MPU must wait
|
||
|
|
* for the BUSY status in OMAP_RTC_STATUS_REG to become zero.
|
||
|
|
* Once the BUSY status is zero, there is a 15 microseconds access
|
||
|
|
* period in which the MPU can program.
|
||
|
|
*/
|
||
|
|
static void omap_rtc_wait_not_busy(struct omap_hwmod *oh)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
/* BUSY may stay active for 1/32768 second (~30 usec) */
|
||
|
|
omap_test_timeout(omap_hwmod_read(oh, OMAP_RTC_STATUS_REG)
|
||
|
|
& OMAP_RTC_STATUS_BUSY, OMAP_RTC_MAX_READY_TIME, i);
|
||
|
|
/* now we have ~15 microseconds to read/write various registers */
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* omap_hwmod_rtc_unlock - Unlock the Kicker mechanism.
|
||
|
|
* @oh: struct omap_hwmod *
|
||
|
|
*
|
||
|
|
* RTC IP have kicker feature. This prevents spurious writes to its registers.
|
||
|
|
* In order to write into any of the RTC registers, KICK values has te be
|
||
|
|
* written in respective KICK registers. This is needed for hwmod to write into
|
||
|
|
* sysconfig register.
|
||
|
|
*/
|
||
|
|
void omap_hwmod_rtc_unlock(struct omap_hwmod *oh)
|
||
|
|
{
|
||
|
|
unsigned long flags;
|
||
|
|
|
||
|
|
local_irq_save(flags);
|
||
|
|
omap_rtc_wait_not_busy(oh);
|
||
|
|
omap_hwmod_write(OMAP_RTC_KICK0_VALUE, oh, OMAP_RTC_KICK0_REG);
|
||
|
|
omap_hwmod_write(OMAP_RTC_KICK1_VALUE, oh, OMAP_RTC_KICK1_REG);
|
||
|
|
local_irq_restore(flags);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* omap_hwmod_rtc_lock - Lock the Kicker mechanism.
|
||
|
|
* @oh: struct omap_hwmod *
|
||
|
|
*
|
||
|
|
* RTC IP have kicker feature. This prevents spurious writes to its registers.
|
||
|
|
* Once the RTC registers are written, KICK mechanism needs to be locked,
|
||
|
|
* in order to prevent any spurious writes. This function locks back the RTC
|
||
|
|
* registers once hwmod completes its write into sysconfig register.
|
||
|
|
*/
|
||
|
|
void omap_hwmod_rtc_lock(struct omap_hwmod *oh)
|
||
|
|
{
|
||
|
|
unsigned long flags;
|
||
|
|
|
||
|
|
local_irq_save(flags);
|
||
|
|
omap_rtc_wait_not_busy(oh);
|
||
|
|
omap_hwmod_write(0x0, oh, OMAP_RTC_KICK0_REG);
|
||
|
|
omap_hwmod_write(0x0, oh, OMAP_RTC_KICK1_REG);
|
||
|
|
local_irq_restore(flags);
|
||
|
|
}
|