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} 119