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-rw-r--r--arch/arm/mach-omap2/timer.c801
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diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
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+++ b/arch/arm/mach-omap2/timer.c
@@ -0,0 +1,801 @@
+/*
+ * linux/arch/arm/mach-omap2/timer.c
+ *
+ * OMAP2 GP timer support.
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ *
+ * Update to use new clocksource/clockevent layers
+ * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
+ * Copyright (C) 2007 MontaVista Software, Inc.
+ *
+ * Original driver:
+ * Copyright (C) 2005 Nokia Corporation
+ * Author: Paul Mundt <paul.mundt@nokia.com>
+ * Juha Yrjölä <juha.yrjola@nokia.com>
+ * OMAP Dual-mode timer framework support by Timo Teras
+ *
+ * Some parts based off of TI's 24xx code:
+ *
+ * Copyright (C) 2004-2009 Texas Instruments, Inc.
+ *
+ * Roughly modelled after the OMAP1 MPU timer code.
+ * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/dmtimer-omap.h>
+#include <linux/sched_clock.h>
+
+#include <asm/mach/time.h>
+#include <asm/smp_twd.h>
+
+#include "omap_hwmod.h"
+#include "omap_device.h"
+#include <plat/counter-32k.h>
+#include <plat/dmtimer.h>
+#include "omap-pm.h"
+
+#include "soc.h"
+#include "common.h"
+#include "control.h"
+#include "powerdomain.h"
+#include "omap-secure.h"
+
+#define REALTIME_COUNTER_BASE 0x48243200
+#define INCREMENTER_NUMERATOR_OFFSET 0x10
+#define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14
+#define NUMERATOR_DENUMERATOR_MASK 0xfffff000
+
+/* Clockevent code */
+
+static struct omap_dm_timer clkev;
+static struct clock_event_device clockevent_gpt;
+
+#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
+static unsigned long arch_timer_freq;
+
+void set_cntfreq(void)
+{
+ omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
+}
+#endif
+
+static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &clockevent_gpt;
+
+ __omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);
+
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction omap2_gp_timer_irq = {
+ .name = "gp_timer",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = omap2_gp_timer_interrupt,
+};
+
+static int omap2_gp_timer_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ __omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
+ 0xffffffff - cycles, OMAP_TIMER_POSTED);
+
+ return 0;
+}
+
+static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ u32 period;
+
+ __omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ period = clkev.rate / HZ;
+ period -= 1;
+ /* Looks like we need to first set the load value separately */
+ __omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG,
+ 0xffffffff - period, OMAP_TIMER_POSTED);
+ __omap_dm_timer_load_start(&clkev,
+ OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
+ 0xffffffff - period, OMAP_TIMER_POSTED);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+}
+
+static struct clock_event_device clockevent_gpt = {
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 300,
+ .set_next_event = omap2_gp_timer_set_next_event,
+ .set_mode = omap2_gp_timer_set_mode,
+};
+
+static struct property device_disabled = {
+ .name = "status",
+ .length = sizeof("disabled"),
+ .value = "disabled",
+};
+
+static const struct of_device_id omap_timer_match[] __initconst = {
+ { .compatible = "ti,omap2420-timer", },
+ { .compatible = "ti,omap3430-timer", },
+ { .compatible = "ti,omap4430-timer", },
+ { .compatible = "ti,omap5430-timer", },
+ { .compatible = "ti,dm814-timer", },
+ { .compatible = "ti,dm816-timer", },
+ { .compatible = "ti,am335x-timer", },
+ { .compatible = "ti,am335x-timer-1ms", },
+ { }
+};
+
+/**
+ * omap_get_timer_dt - get a timer using device-tree
+ * @match - device-tree match structure for matching a device type
+ * @property - optional timer property to match
+ *
+ * Helper function to get a timer during early boot using device-tree for use
+ * as kernel system timer. Optionally, the property argument can be used to
+ * select a timer with a specific property. Once a timer is found then mark
+ * the timer node in device-tree as disabled, to prevent the kernel from
+ * registering this timer as a platform device and so no one else can use it.
+ */
+static struct device_node * __init omap_get_timer_dt(const struct of_device_id *match,
+ const char *property)
+{
+ struct device_node *np;
+
+ for_each_matching_node(np, match) {
+ if (!of_device_is_available(np))
+ continue;
+
+ if (property && !of_get_property(np, property, NULL))
+ continue;
+
+ if (!property && (of_get_property(np, "ti,timer-alwon", NULL) ||
+ of_get_property(np, "ti,timer-dsp", NULL) ||
+ of_get_property(np, "ti,timer-pwm", NULL) ||
+ of_get_property(np, "ti,timer-secure", NULL)))
+ continue;
+
+ of_add_property(np, &device_disabled);
+ return np;
+ }
+
+ return NULL;
+}
+
+/**
+ * omap_dmtimer_init - initialisation function when device tree is used
+ *
+ * For secure OMAP3 devices, timers with device type "timer-secure" cannot
+ * be used by the kernel as they are reserved. Therefore, to prevent the
+ * kernel registering these devices remove them dynamically from the device
+ * tree on boot.
+ */
+static void __init omap_dmtimer_init(void)
+{
+ struct device_node *np;
+
+ if (!cpu_is_omap34xx())
+ return;
+
+ /* If we are a secure device, remove any secure timer nodes */
+ if ((omap_type() != OMAP2_DEVICE_TYPE_GP)) {
+ np = omap_get_timer_dt(omap_timer_match, "ti,timer-secure");
+ if (np)
+ of_node_put(np);
+ }
+}
+
+/**
+ * omap_dm_timer_get_errata - get errata flags for a timer
+ *
+ * Get the timer errata flags that are specific to the OMAP device being used.
+ */
+static u32 __init omap_dm_timer_get_errata(void)
+{
+ if (cpu_is_omap24xx())
+ return 0;
+
+ return OMAP_TIMER_ERRATA_I103_I767;
+}
+
+static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
+ const char *fck_source,
+ const char *property,
+ const char **timer_name,
+ int posted)
+{
+ char name[10]; /* 10 = sizeof("gptXX_Xck0") */
+ const char *oh_name = NULL;
+ struct device_node *np;
+ struct omap_hwmod *oh;
+ struct resource irq, mem;
+ struct clk *src;
+ int r = 0;
+
+ if (of_have_populated_dt()) {
+ np = omap_get_timer_dt(omap_timer_match, property);
+ if (!np)
+ return -ENODEV;
+
+ of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
+ if (!oh_name)
+ return -ENODEV;
+
+ timer->irq = irq_of_parse_and_map(np, 0);
+ if (!timer->irq)
+ return -ENXIO;
+
+ timer->io_base = of_iomap(np, 0);
+
+ of_node_put(np);
+ } else {
+ if (omap_dm_timer_reserve_systimer(timer->id))
+ return -ENODEV;
+
+ sprintf(name, "timer%d", timer->id);
+ oh_name = name;
+ }
+
+ oh = omap_hwmod_lookup(oh_name);
+ if (!oh)
+ return -ENODEV;
+
+ *timer_name = oh->name;
+
+ if (!of_have_populated_dt()) {
+ r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
+ &irq);
+ if (r)
+ return -ENXIO;
+ timer->irq = irq.start;
+
+ r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
+ &mem);
+ if (r)
+ return -ENXIO;
+
+ /* Static mapping, never released */
+ timer->io_base = ioremap(mem.start, mem.end - mem.start);
+ }
+
+ if (!timer->io_base)
+ return -ENXIO;
+
+ /* After the dmtimer is using hwmod these clocks won't be needed */
+ timer->fclk = clk_get(NULL, omap_hwmod_get_main_clk(oh));
+ if (IS_ERR(timer->fclk))
+ return PTR_ERR(timer->fclk);
+
+ src = clk_get(NULL, fck_source);
+ if (IS_ERR(src))
+ return PTR_ERR(src);
+
+ r = clk_set_parent(timer->fclk, src);
+ if (r < 0) {
+ pr_warn("%s: %s cannot set source\n", __func__, oh->name);
+ clk_put(src);
+ return r;
+ }
+
+ clk_put(src);
+
+ omap_hwmod_setup_one(oh_name);
+ omap_hwmod_enable(oh);
+ __omap_dm_timer_init_regs(timer);
+
+ if (posted)
+ __omap_dm_timer_enable_posted(timer);
+
+ /* Check that the intended posted configuration matches the actual */
+ if (posted != timer->posted)
+ return -EINVAL;
+
+ timer->rate = clk_get_rate(timer->fclk);
+ timer->reserved = 1;
+
+ return r;
+}
+
+static void __init omap2_gp_clockevent_init(int gptimer_id,
+ const char *fck_source,
+ const char *property)
+{
+ int res;
+
+ clkev.id = gptimer_id;
+ clkev.errata = omap_dm_timer_get_errata();
+
+ /*
+ * For clock-event timers we never read the timer counter and
+ * so we are not impacted by errata i103 and i767. Therefore,
+ * we can safely ignore this errata for clock-event timers.
+ */
+ __omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
+
+ res = omap_dm_timer_init_one(&clkev, fck_source, property,
+ &clockevent_gpt.name, OMAP_TIMER_POSTED);
+ BUG_ON(res);
+
+ omap2_gp_timer_irq.dev_id = &clkev;
+ setup_irq(clkev.irq, &omap2_gp_timer_irq);
+
+ __omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
+
+ clockevent_gpt.cpumask = cpu_possible_mask;
+ clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
+ clockevents_config_and_register(&clockevent_gpt, clkev.rate,
+ 3, /* Timer internal resynch latency */
+ 0xffffffff);
+
+ pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
+ clkev.rate);
+}
+
+/* Clocksource code */
+static struct omap_dm_timer clksrc;
+static bool use_gptimer_clksrc __initdata;
+
+/*
+ * clocksource
+ */
+static cycle_t clocksource_read_cycles(struct clocksource *cs)
+{
+ return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
+ OMAP_TIMER_NONPOSTED);
+}
+
+static struct clocksource clocksource_gpt = {
+ .rating = 300,
+ .read = clocksource_read_cycles,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static u64 notrace dmtimer_read_sched_clock(void)
+{
+ if (clksrc.reserved)
+ return __omap_dm_timer_read_counter(&clksrc,
+ OMAP_TIMER_NONPOSTED);
+
+ return 0;
+}
+
+static const struct of_device_id omap_counter_match[] __initconst = {
+ { .compatible = "ti,omap-counter32k", },
+ { }
+};
+
+/* Setup free-running counter for clocksource */
+static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
+{
+ int ret;
+ struct device_node *np = NULL;
+ struct omap_hwmod *oh;
+ void __iomem *vbase;
+ const char *oh_name = "counter_32k";
+
+ /*
+ * If device-tree is present, then search the DT blob
+ * to see if the 32kHz counter is supported.
+ */
+ if (of_have_populated_dt()) {
+ np = omap_get_timer_dt(omap_counter_match, NULL);
+ if (!np)
+ return -ENODEV;
+
+ of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
+ if (!oh_name)
+ return -ENODEV;
+ }
+
+ /*
+ * First check hwmod data is available for sync32k counter
+ */
+ oh = omap_hwmod_lookup(oh_name);
+ if (!oh || oh->slaves_cnt == 0)
+ return -ENODEV;
+
+ omap_hwmod_setup_one(oh_name);
+
+ if (np) {
+ vbase = of_iomap(np, 0);
+ of_node_put(np);
+ } else {
+ vbase = omap_hwmod_get_mpu_rt_va(oh);
+ }
+
+ if (!vbase) {
+ pr_warn("%s: failed to get counter_32k resource\n", __func__);
+ return -ENXIO;
+ }
+
+ ret = omap_hwmod_enable(oh);
+ if (ret) {
+ pr_warn("%s: failed to enable counter_32k module (%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = omap_init_clocksource_32k(vbase);
+ if (ret) {
+ pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
+ __func__, ret);
+ omap_hwmod_idle(oh);
+ }
+
+ return ret;
+}
+
+static void __init omap2_gptimer_clocksource_init(int gptimer_id,
+ const char *fck_source,
+ const char *property)
+{
+ int res;
+
+ clksrc.id = gptimer_id;
+ clksrc.errata = omap_dm_timer_get_errata();
+
+ res = omap_dm_timer_init_one(&clksrc, fck_source, property,
+ &clocksource_gpt.name,
+ OMAP_TIMER_NONPOSTED);
+ BUG_ON(res);
+
+ __omap_dm_timer_load_start(&clksrc,
+ OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
+ OMAP_TIMER_NONPOSTED);
+ sched_clock_register(dmtimer_read_sched_clock, 32, clksrc.rate);
+
+ if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
+ pr_err("Could not register clocksource %s\n",
+ clocksource_gpt.name);
+ else
+ pr_info("OMAP clocksource: %s at %lu Hz\n",
+ clocksource_gpt.name, clksrc.rate);
+}
+
+#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
+/*
+ * The realtime counter also called master counter, is a free-running
+ * counter, which is related to real time. It produces the count used
+ * by the CPU local timer peripherals in the MPU cluster. The timer counts
+ * at a rate of 6.144 MHz. Because the device operates on different clocks
+ * in different power modes, the master counter shifts operation between
+ * clocks, adjusting the increment per clock in hardware accordingly to
+ * maintain a constant count rate.
+ */
+static void __init realtime_counter_init(void)
+{
+ void __iomem *base;
+ static struct clk *sys_clk;
+ unsigned long rate;
+ unsigned int reg;
+ unsigned long long num, den;
+
+ base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
+ if (!base) {
+ pr_err("%s: ioremap failed\n", __func__);
+ return;
+ }
+ sys_clk = clk_get(NULL, "sys_clkin");
+ if (IS_ERR(sys_clk)) {
+ pr_err("%s: failed to get system clock handle\n", __func__);
+ iounmap(base);
+ return;
+ }
+
+ rate = clk_get_rate(sys_clk);
+
+ if (soc_is_dra7xx()) {
+ /*
+ * Errata i856 says the 32.768KHz crystal does not start at
+ * power on, so the CPU falls back to an emulated 32KHz clock
+ * based on sysclk / 610 instead. This causes the master counter
+ * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
+ * (OR sysclk * 75 / 244)
+ *
+ * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
+ * Of course any board built without a populated 32.768KHz
+ * crystal would also need this fix even if the CPU is fixed
+ * later.
+ *
+ * Either case can be detected by using the two speedselect bits
+ * If they are not 0, then the 32.768KHz clock driving the
+ * coarse counter that corrects the fine counter every time it
+ * ticks is actually rate/610 rather than 32.768KHz and we
+ * should compensate to avoid the 570ppm (at 20MHz, much worse
+ * at other rates) too fast system time.
+ */
+ reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
+ if (reg & DRA7_SPEEDSELECT_MASK) {
+ num = 75;
+ den = 244;
+ goto sysclk1_based;
+ }
+ }
+
+ /* Numerator/denumerator values refer TRM Realtime Counter section */
+ switch (rate) {
+ case 12000000:
+ num = 64;
+ den = 125;
+ break;
+ case 13000000:
+ num = 768;
+ den = 1625;
+ break;
+ case 19200000:
+ num = 8;
+ den = 25;
+ break;
+ case 20000000:
+ num = 192;
+ den = 625;
+ break;
+ case 26000000:
+ num = 384;
+ den = 1625;
+ break;
+ case 27000000:
+ num = 256;
+ den = 1125;
+ break;
+ case 38400000:
+ default:
+ /* Program it for 38.4 MHz */
+ num = 4;
+ den = 25;
+ break;
+ }
+
+sysclk1_based:
+ /* Program numerator and denumerator registers */
+ reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
+ NUMERATOR_DENUMERATOR_MASK;
+ reg |= num;
+ writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);
+
+ reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
+ NUMERATOR_DENUMERATOR_MASK;
+ reg |= den;
+ writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
+
+ arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
+ set_cntfreq();
+
+ iounmap(base);
+}
+#else
+static inline void __init realtime_counter_init(void)
+{}
+#endif
+
+#define OMAP_SYS_GP_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop, \
+ clksrc_nr, clksrc_src, clksrc_prop) \
+void __init omap##name##_gptimer_timer_init(void) \
+{ \
+ omap_clk_init(); \
+ omap_dmtimer_init(); \
+ omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop); \
+ omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
+ clksrc_prop); \
+}
+
+#define OMAP_SYS_32K_TIMER_INIT(name, clkev_nr, clkev_src, clkev_prop, \
+ clksrc_nr, clksrc_src, clksrc_prop) \
+void __init omap##name##_sync32k_timer_init(void) \
+{ \
+ omap_clk_init(); \
+ omap_dmtimer_init(); \
+ omap2_gp_clockevent_init((clkev_nr), clkev_src, clkev_prop); \
+ /* Enable the use of clocksource="gp_timer" kernel parameter */ \
+ if (use_gptimer_clksrc) \
+ omap2_gptimer_clocksource_init((clksrc_nr), clksrc_src, \
+ clksrc_prop); \
+ else \
+ omap2_sync32k_clocksource_init(); \
+}
+
+#ifdef CONFIG_ARCH_OMAP2
+OMAP_SYS_32K_TIMER_INIT(2, 1, "timer_32k_ck", "ti,timer-alwon",
+ 2, "timer_sys_ck", NULL);
+#endif /* CONFIG_ARCH_OMAP2 */
+
+#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
+OMAP_SYS_32K_TIMER_INIT(3, 1, "timer_32k_ck", "ti,timer-alwon",
+ 2, "timer_sys_ck", NULL);
+OMAP_SYS_32K_TIMER_INIT(3_secure, 12, "secure_32k_fck", "ti,timer-secure",
+ 2, "timer_sys_ck", NULL);
+#endif /* CONFIG_ARCH_OMAP3 */
+
+#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX) || \
+ defined(CONFIG_SOC_AM43XX)
+OMAP_SYS_GP_TIMER_INIT(3, 2, "timer_sys_ck", NULL,
+ 1, "timer_sys_ck", "ti,timer-alwon");
+#endif
+
+#if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \
+ defined(CONFIG_SOC_DRA7XX)
+static OMAP_SYS_32K_TIMER_INIT(4, 1, "timer_32k_ck", "ti,timer-alwon",
+ 2, "sys_clkin_ck", NULL);
+#endif
+
+#ifdef CONFIG_ARCH_OMAP4
+#ifdef CONFIG_HAVE_ARM_TWD
+static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, OMAP44XX_LOCAL_TWD_BASE, 29);
+void __init omap4_local_timer_init(void)
+{
+ omap4_sync32k_timer_init();
+ /* Local timers are not supprted on OMAP4430 ES1.0 */
+ if (omap_rev() != OMAP4430_REV_ES1_0) {
+ int err;
+
+ if (of_have_populated_dt()) {
+ clocksource_of_init();
+ return;
+ }
+
+ err = twd_local_timer_register(&twd_local_timer);
+ if (err)
+ pr_err("twd_local_timer_register failed %d\n", err);
+ }
+}
+#else
+void __init omap4_local_timer_init(void)
+{
+ omap4_sync32k_timer_init();
+}
+#endif /* CONFIG_HAVE_ARM_TWD */
+#endif /* CONFIG_ARCH_OMAP4 */
+
+#if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
+void __init omap5_realtime_timer_init(void)
+{
+ omap4_sync32k_timer_init();
+ realtime_counter_init();
+
+ clocksource_of_init();
+}
+#endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
+
+/**
+ * omap_timer_init - build and register timer device with an
+ * associated timer hwmod
+ * @oh: timer hwmod pointer to be used to build timer device
+ * @user: parameter that can be passed from calling hwmod API
+ *
+ * Called by omap_hwmod_for_each_by_class to register each of the timer
+ * devices present in the system. The number of timer devices is known
+ * by parsing through the hwmod database for a given class name. At the
+ * end of function call memory is allocated for timer device and it is
+ * registered to the framework ready to be proved by the driver.
+ */
+static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
+{
+ int id;
+ int ret = 0;
+ char *name = "omap_timer";
+ struct dmtimer_platform_data *pdata;
+ struct platform_device *pdev;
+ struct omap_timer_capability_dev_attr *timer_dev_attr;
+
+ pr_debug("%s: %s\n", __func__, oh->name);
+
+ /* on secure device, do not register secure timer */
+ timer_dev_attr = oh->dev_attr;
+ if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
+ if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
+ return ret;
+
+ pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ pr_err("%s: No memory for [%s]\n", __func__, oh->name);
+ return -ENOMEM;
+ }
+
+ /*
+ * Extract the IDs from name field in hwmod database
+ * and use the same for constructing ids' for the
+ * timer devices. In a way, we are avoiding usage of
+ * static variable witin the function to do the same.
+ * CAUTION: We have to be careful and make sure the
+ * name in hwmod database does not change in which case
+ * we might either make corresponding change here or
+ * switch back static variable mechanism.
+ */
+ sscanf(oh->name, "timer%2d", &id);
+
+ if (timer_dev_attr)
+ pdata->timer_capability = timer_dev_attr->timer_capability;
+
+ pdata->timer_errata = omap_dm_timer_get_errata();
+ pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
+
+ pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));
+
+ if (IS_ERR(pdev)) {
+ pr_err("%s: Can't build omap_device for %s: %s.\n",
+ __func__, name, oh->name);
+ ret = -EINVAL;
+ }
+
+ kfree(pdata);
+
+ return ret;
+}
+
+/**
+ * omap2_dm_timer_init - top level regular device initialization
+ *
+ * Uses dedicated hwmod api to parse through hwmod database for
+ * given class name and then build and register the timer device.
+ */
+static int __init omap2_dm_timer_init(void)
+{
+ int ret;
+
+ /* If dtb is there, the devices will be created dynamically */
+ if (of_have_populated_dt())
+ return -ENODEV;
+
+ ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
+ if (unlikely(ret)) {
+ pr_err("%s: device registration failed.\n", __func__);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+omap_arch_initcall(omap2_dm_timer_init);
+
+/**
+ * omap2_override_clocksource - clocksource override with user configuration
+ *
+ * Allows user to override default clocksource, using kernel parameter
+ * clocksource="gp_timer" (For all OMAP2PLUS architectures)
+ *
+ * Note that, here we are using same standard kernel parameter "clocksource=",
+ * and not introducing any OMAP specific interface.
+ */
+static int __init omap2_override_clocksource(char *str)
+{
+ if (!str)
+ return 0;
+ /*
+ * For OMAP architecture, we only have two options
+ * - sync_32k (default)
+ * - gp_timer (sys_clk based)
+ */
+ if (!strcmp(str, "gp_timer"))
+ use_gptimer_clksrc = true;
+
+ return 0;
+}
+early_param("clocksource", omap2_override_clocksource);