16b1baefeSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2fe851f56SFelipe Balbi /** 3fe851f56SFelipe Balbi * timer-ti-32k.c - OMAP2 32k Timer Support 4fe851f56SFelipe Balbi * 5fe851f56SFelipe Balbi * Copyright (C) 2009 Nokia Corporation 6fe851f56SFelipe Balbi * 7fe851f56SFelipe Balbi * Update to use new clocksource/clockevent layers 8fe851f56SFelipe Balbi * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com> 9fe851f56SFelipe Balbi * Copyright (C) 2007 MontaVista Software, Inc. 10fe851f56SFelipe Balbi * 11fe851f56SFelipe Balbi * Original driver: 12fe851f56SFelipe Balbi * Copyright (C) 2005 Nokia Corporation 13fe851f56SFelipe Balbi * Author: Paul Mundt <paul.mundt@nokia.com> 14fe851f56SFelipe Balbi * Juha Yrjölä <juha.yrjola@nokia.com> 15fe851f56SFelipe Balbi * OMAP Dual-mode timer framework support by Timo Teras 16fe851f56SFelipe Balbi * 17fe851f56SFelipe Balbi * Some parts based off of TI's 24xx code: 18fe851f56SFelipe Balbi * 19fe851f56SFelipe Balbi * Copyright (C) 2004-2009 Texas Instruments, Inc. 20fe851f56SFelipe Balbi * 21fe851f56SFelipe Balbi * Roughly modelled after the OMAP1 MPU timer code. 22fe851f56SFelipe Balbi * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com> 23fe851f56SFelipe Balbi * 24fe851f56SFelipe Balbi * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com 25fe851f56SFelipe Balbi */ 26fe851f56SFelipe Balbi 27fe851f56SFelipe Balbi #include <linux/init.h> 28fe851f56SFelipe Balbi #include <linux/time.h> 29fe851f56SFelipe Balbi #include <linux/sched_clock.h> 30fe851f56SFelipe Balbi #include <linux/clocksource.h> 31fe851f56SFelipe Balbi #include <linux/of.h> 32fe851f56SFelipe Balbi #include <linux/of_address.h> 33fe851f56SFelipe Balbi 34fe851f56SFelipe Balbi /* 35fe851f56SFelipe Balbi * 32KHz clocksource ... always available, on pretty most chips except 36fe851f56SFelipe Balbi * OMAP 730 and 1510. Other timers could be used as clocksources, with 37fe851f56SFelipe Balbi * higher resolution in free-running counter modes (e.g. 12 MHz xtal), 38fe851f56SFelipe Balbi * but systems won't necessarily want to spend resources that way. 39fe851f56SFelipe Balbi */ 40fe851f56SFelipe Balbi 41fe851f56SFelipe Balbi #define OMAP2_32KSYNCNT_REV_OFF 0x0 42fe851f56SFelipe Balbi #define OMAP2_32KSYNCNT_REV_SCHEME (0x3 << 30) 43fe851f56SFelipe Balbi #define OMAP2_32KSYNCNT_CR_OFF_LOW 0x10 44fe851f56SFelipe Balbi #define OMAP2_32KSYNCNT_CR_OFF_HIGH 0x30 45fe851f56SFelipe Balbi 46fe851f56SFelipe Balbi struct ti_32k { 47fe851f56SFelipe Balbi void __iomem *base; 48fe851f56SFelipe Balbi void __iomem *counter; 49fe851f56SFelipe Balbi struct clocksource cs; 50fe851f56SFelipe Balbi }; 51fe851f56SFelipe Balbi 52fe851f56SFelipe Balbi static inline struct ti_32k *to_ti_32k(struct clocksource *cs) 53fe851f56SFelipe Balbi { 54fe851f56SFelipe Balbi return container_of(cs, struct ti_32k, cs); 55fe851f56SFelipe Balbi } 56fe851f56SFelipe Balbi 57a5a1d1c2SThomas Gleixner static u64 notrace ti_32k_read_cycles(struct clocksource *cs) 58fe851f56SFelipe Balbi { 59fe851f56SFelipe Balbi struct ti_32k *ti = to_ti_32k(cs); 60fe851f56SFelipe Balbi 61a5a1d1c2SThomas Gleixner return (u64)readl_relaxed(ti->counter); 62fe851f56SFelipe Balbi } 63fe851f56SFelipe Balbi 64fe851f56SFelipe Balbi static struct ti_32k ti_32k_timer = { 65fe851f56SFelipe Balbi .cs = { 66fe851f56SFelipe Balbi .name = "32k_counter", 67fe851f56SFelipe Balbi .rating = 250, 68fe851f56SFelipe Balbi .read = ti_32k_read_cycles, 69fe851f56SFelipe Balbi .mask = CLOCKSOURCE_MASK(32), 70c77aee71SKeerthy .flags = CLOCK_SOURCE_IS_CONTINUOUS, 71fe851f56SFelipe Balbi }, 72fe851f56SFelipe Balbi }; 73fe851f56SFelipe Balbi 74fe851f56SFelipe Balbi static u64 notrace omap_32k_read_sched_clock(void) 75fe851f56SFelipe Balbi { 76fe851f56SFelipe Balbi return ti_32k_read_cycles(&ti_32k_timer.cs); 77fe851f56SFelipe Balbi } 78fe851f56SFelipe Balbi 790a8e7d49SDaniel Lezcano static int __init ti_32k_timer_init(struct device_node *np) 80fe851f56SFelipe Balbi { 81fe851f56SFelipe Balbi int ret; 82fe851f56SFelipe Balbi 83fe851f56SFelipe Balbi ti_32k_timer.base = of_iomap(np, 0); 84fe851f56SFelipe Balbi if (!ti_32k_timer.base) { 85fe851f56SFelipe Balbi pr_err("Can't ioremap 32k timer base\n"); 860a8e7d49SDaniel Lezcano return -ENXIO; 87fe851f56SFelipe Balbi } 88fe851f56SFelipe Balbi 893b7d96a0SKeerthy if (!of_machine_is_compatible("ti,am43")) 903b7d96a0SKeerthy ti_32k_timer.cs.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP; 913b7d96a0SKeerthy 92fe851f56SFelipe Balbi ti_32k_timer.counter = ti_32k_timer.base; 93fe851f56SFelipe Balbi 94fe851f56SFelipe Balbi /* 95fe851f56SFelipe Balbi * 32k sync Counter IP register offsets vary between the highlander 96fe851f56SFelipe Balbi * version and the legacy ones. 97fe851f56SFelipe Balbi * 98fe851f56SFelipe Balbi * The 'SCHEME' bits(30-31) of the revision register is used to identify 99fe851f56SFelipe Balbi * the version. 100fe851f56SFelipe Balbi */ 101fe851f56SFelipe Balbi if (readl_relaxed(ti_32k_timer.base + OMAP2_32KSYNCNT_REV_OFF) & 102fe851f56SFelipe Balbi OMAP2_32KSYNCNT_REV_SCHEME) 103fe851f56SFelipe Balbi ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_HIGH; 104fe851f56SFelipe Balbi else 105fe851f56SFelipe Balbi ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_LOW; 106fe851f56SFelipe Balbi 107fe851f56SFelipe Balbi ret = clocksource_register_hz(&ti_32k_timer.cs, 32768); 108fe851f56SFelipe Balbi if (ret) { 109fe851f56SFelipe Balbi pr_err("32k_counter: can't register clocksource\n"); 1100a8e7d49SDaniel Lezcano return ret; 111fe851f56SFelipe Balbi } 112fe851f56SFelipe Balbi 113fe851f56SFelipe Balbi sched_clock_register(omap_32k_read_sched_clock, 32, 32768); 114fe851f56SFelipe Balbi pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n"); 1150a8e7d49SDaniel Lezcano 1160a8e7d49SDaniel Lezcano return 0; 117fe851f56SFelipe Balbi } 11817273395SDaniel Lezcano TIMER_OF_DECLARE(ti_32k_timer, "ti,omap-counter32k", 119fe851f56SFelipe Balbi ti_32k_timer_init); 120