1/*
  2 * OMAP IP block custom reset and preprogramming stubs
  3 *
  4 * Copyright (C) 2012 Texas Instruments, Inc.
  5 * Paul Walmsley
  6 *
  7 * A small number of IP blocks need custom reset and preprogramming
  8 * functions.  The stubs in this file provide a standard way for the
  9 * hwmod code to call these functions, which are to be located under
 10 * drivers/.
 11 *
 12 * This program is free software; you can redistribute it and/or
 13 * modify it under the terms of the GNU General Public License as
 14 * published by the Free Software Foundation version 2.
 15 *
 16 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 17 * kind, whether express or implied; without even the implied warranty
 18 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 19 * GNU General Public License for more details.
 20 *
 21 * You should have received a copy of the GNU General Public License
 22 * along with this program; if not, write to the Free Software
 23 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 24 * 02110-1301 USA
 25 */
 26#include <linux/kernel.h>
 27#include <linux/errno.h>
 28
 29#include <sound/aess.h>
 30
 31#include "omap_hwmod.h"
 32#include "common.h"
 33
 34#define OMAP_RTC_STATUS_REG	0x44
 35#define OMAP_RTC_KICK0_REG	0x6c
 36#define OMAP_RTC_KICK1_REG	0x70
 37
 38#define OMAP_RTC_KICK0_VALUE	0x83E70B13
 39#define OMAP_RTC_KICK1_VALUE	0x95A4F1E0
 40#define OMAP_RTC_STATUS_BUSY	BIT(0)
 41#define OMAP_RTC_MAX_READY_TIME	50
 42
 43/**
 44 * omap_hwmod_aess_preprogram - enable AESS internal autogating
 45 * @oh: struct omap_hwmod *
 46 *
 47 * The AESS will not IdleAck to the PRCM until its internal autogating
 48 * is enabled.  Since internal autogating is disabled by default after
 49 * AESS reset, we must enable autogating after the hwmod code resets
 50 * the AESS.  Returns 0.
 51 */
 52int omap_hwmod_aess_preprogram(struct omap_hwmod *oh)
 53{
 54	void __iomem *va;
 55
 56	va = omap_hwmod_get_mpu_rt_va(oh);
 57	if (!va)
 58		return -EINVAL;
 59
 60	aess_enable_autogating(va);
 61
 62	return 0;
 63}
 64
 65/**
 66 * omap_rtc_wait_not_busy - Wait for the RTC BUSY flag
 67 * @oh: struct omap_hwmod *
 68 *
 69 * For updating certain RTC registers, the MPU must wait
 70 * for the BUSY status in OMAP_RTC_STATUS_REG to become zero.
 71 * Once the BUSY status is zero, there is a 15 microseconds access
 72 * period in which the MPU can program.
 73 */
 74static void omap_rtc_wait_not_busy(struct omap_hwmod *oh)
 75{
 76	int i;
 77
 78	/* BUSY may stay active for 1/32768 second (~30 usec) */
 79	omap_test_timeout(omap_hwmod_read(oh, OMAP_RTC_STATUS_REG)
 80			  & OMAP_RTC_STATUS_BUSY, OMAP_RTC_MAX_READY_TIME, i);
 81	/* now we have ~15 microseconds to read/write various registers */
 82}
 83
 84/**
 85 * omap_hwmod_rtc_unlock - Unlock the Kicker mechanism.
 86 * @oh: struct omap_hwmod *
 87 *
 88 * RTC IP have kicker feature. This prevents spurious writes to its registers.
 89 * In order to write into any of the RTC registers, KICK values has te be
 90 * written in respective KICK registers. This is needed for hwmod to write into
 91 * sysconfig register.
 92 */
 93void omap_hwmod_rtc_unlock(struct omap_hwmod *oh)
 94{
 95	local_irq_disable();
 96	omap_rtc_wait_not_busy(oh);
 97	omap_hwmod_write(OMAP_RTC_KICK0_VALUE, oh, OMAP_RTC_KICK0_REG);
 98	omap_hwmod_write(OMAP_RTC_KICK1_VALUE, oh, OMAP_RTC_KICK1_REG);
 99	local_irq_enable();
100}
101
102/**
103 * omap_hwmod_rtc_lock - Lock the Kicker mechanism.
104 * @oh: struct omap_hwmod *
105 *
106 * RTC IP have kicker feature. This prevents spurious writes to its registers.
107 * Once the RTC registers are written, KICK mechanism needs to be locked,
108 * in order to prevent any spurious writes. This function locks back the RTC
109 * registers once hwmod completes its write into sysconfig register.
110 */
111void omap_hwmod_rtc_lock(struct omap_hwmod *oh)
112{
113	local_irq_disable();
114	omap_rtc_wait_not_busy(oh);
115	omap_hwmod_write(0x0, oh, OMAP_RTC_KICK0_REG);
116	omap_hwmod_write(0x0, oh, OMAP_RTC_KICK1_REG);
117	local_irq_enable();
118}