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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /drivers/clocksource/timer-sp804.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'drivers/clocksource/timer-sp804.c')
-rw-r--r--drivers/clocksource/timer-sp804.c310
1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c
new file mode 100644
index 000000000..ca02503f1
--- /dev/null
+++ b/drivers/clocksource/timer-sp804.c
@@ -0,0 +1,310 @@
+/*
+ * linux/drivers/clocksource/timer-sp.c
+ *
+ * Copyright (C) 1999 - 2003 ARM Limited
+ * Copyright (C) 2000 Deep Blue Solutions Ltd
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <clocksource/timer-sp804.h>
+
+#include "timer-sp.h"
+
+static long __init sp804_get_clock_rate(struct clk *clk)
+{
+ long rate;
+ int err;
+
+ err = clk_prepare(clk);
+ if (err) {
+ pr_err("sp804: clock failed to prepare: %d\n", err);
+ clk_put(clk);
+ return err;
+ }
+
+ err = clk_enable(clk);
+ if (err) {
+ pr_err("sp804: clock failed to enable: %d\n", err);
+ clk_unprepare(clk);
+ clk_put(clk);
+ return err;
+ }
+
+ rate = clk_get_rate(clk);
+ if (rate < 0) {
+ pr_err("sp804: clock failed to get rate: %ld\n", rate);
+ clk_disable(clk);
+ clk_unprepare(clk);
+ clk_put(clk);
+ }
+
+ return rate;
+}
+
+static void __iomem *sched_clock_base;
+
+static u64 notrace sp804_read(void)
+{
+ return ~readl_relaxed(sched_clock_base + TIMER_VALUE);
+}
+
+void __init sp804_timer_disable(void __iomem *base)
+{
+ writel(0, base + TIMER_CTRL);
+}
+
+void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
+ const char *name,
+ struct clk *clk,
+ int use_sched_clock)
+{
+ long rate;
+
+ if (!clk) {
+ clk = clk_get_sys("sp804", name);
+ if (IS_ERR(clk)) {
+ pr_err("sp804: clock not found: %d\n",
+ (int)PTR_ERR(clk));
+ return;
+ }
+ }
+
+ rate = sp804_get_clock_rate(clk);
+
+ if (rate < 0)
+ return;
+
+ /* setup timer 0 as free-running clocksource */
+ writel(0, base + TIMER_CTRL);
+ writel(0xffffffff, base + TIMER_LOAD);
+ writel(0xffffffff, base + TIMER_VALUE);
+ writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
+ base + TIMER_CTRL);
+
+ clocksource_mmio_init(base + TIMER_VALUE, name,
+ rate, 200, 32, clocksource_mmio_readl_down);
+
+ if (use_sched_clock) {
+ sched_clock_base = base;
+ sched_clock_register(sp804_read, 32, rate);
+ }
+}
+
+
+static void __iomem *clkevt_base;
+static unsigned long clkevt_reload;
+
+/*
+ * IRQ handler for the timer
+ */
+static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+
+ /* clear the interrupt */
+ writel(1, clkevt_base + TIMER_INTCLR);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static void sp804_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE;
+
+ writel(ctrl, clkevt_base + TIMER_CTRL);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ writel(clkevt_reload, clkevt_base + TIMER_LOAD);
+ ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
+ break;
+
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* period set, and timer enabled in 'next_event' hook */
+ ctrl |= TIMER_CTRL_ONESHOT;
+ break;
+
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ default:
+ break;
+ }
+
+ writel(ctrl, clkevt_base + TIMER_CTRL);
+}
+
+static int sp804_set_next_event(unsigned long next,
+ struct clock_event_device *evt)
+{
+ unsigned long ctrl = readl(clkevt_base + TIMER_CTRL);
+
+ writel(next, clkevt_base + TIMER_LOAD);
+ writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL);
+
+ return 0;
+}
+
+static struct clock_event_device sp804_clockevent = {
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
+ CLOCK_EVT_FEAT_DYNIRQ,
+ .set_mode = sp804_set_mode,
+ .set_next_event = sp804_set_next_event,
+ .rating = 300,
+};
+
+static struct irqaction sp804_timer_irq = {
+ .name = "timer",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = sp804_timer_interrupt,
+ .dev_id = &sp804_clockevent,
+};
+
+void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
+{
+ struct clock_event_device *evt = &sp804_clockevent;
+ long rate;
+
+ if (!clk)
+ clk = clk_get_sys("sp804", name);
+ if (IS_ERR(clk)) {
+ pr_err("sp804: %s clock not found: %d\n", name,
+ (int)PTR_ERR(clk));
+ return;
+ }
+
+ rate = sp804_get_clock_rate(clk);
+ if (rate < 0)
+ return;
+
+ clkevt_base = base;
+ clkevt_reload = DIV_ROUND_CLOSEST(rate, HZ);
+ evt->name = name;
+ evt->irq = irq;
+ evt->cpumask = cpu_possible_mask;
+
+ writel(0, base + TIMER_CTRL);
+
+ setup_irq(irq, &sp804_timer_irq);
+ clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
+}
+
+static void __init sp804_of_init(struct device_node *np)
+{
+ static bool initialized = false;
+ void __iomem *base;
+ int irq;
+ u32 irq_num = 0;
+ struct clk *clk1, *clk2;
+ const char *name = of_get_property(np, "compatible", NULL);
+
+ base = of_iomap(np, 0);
+ if (WARN_ON(!base))
+ return;
+
+ /* Ensure timers are disabled */
+ writel(0, base + TIMER_CTRL);
+ writel(0, base + TIMER_2_BASE + TIMER_CTRL);
+
+ if (initialized || !of_device_is_available(np))
+ goto err;
+
+ clk1 = of_clk_get(np, 0);
+ if (IS_ERR(clk1))
+ clk1 = NULL;
+
+ /* Get the 2nd clock if the timer has 3 timer clocks */
+ if (of_count_phandle_with_args(np, "clocks", "#clock-cells") == 3) {
+ clk2 = of_clk_get(np, 1);
+ if (IS_ERR(clk2)) {
+ pr_err("sp804: %s clock not found: %d\n", np->name,
+ (int)PTR_ERR(clk2));
+ clk2 = NULL;
+ }
+ } else
+ clk2 = clk1;
+
+ irq = irq_of_parse_and_map(np, 0);
+ if (irq <= 0)
+ goto err;
+
+ of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
+ if (irq_num == 2) {
+ __sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
+ __sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
+ } else {
+ __sp804_clockevents_init(base, irq, clk1 , name);
+ __sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
+ name, clk2, 1);
+ }
+ initialized = true;
+
+ return;
+err:
+ iounmap(base);
+}
+CLOCKSOURCE_OF_DECLARE(sp804, "arm,sp804", sp804_of_init);
+
+static void __init integrator_cp_of_init(struct device_node *np)
+{
+ static int init_count = 0;
+ void __iomem *base;
+ int irq;
+ const char *name = of_get_property(np, "compatible", NULL);
+ struct clk *clk;
+
+ base = of_iomap(np, 0);
+ if (WARN_ON(!base))
+ return;
+ clk = of_clk_get(np, 0);
+ if (WARN_ON(IS_ERR(clk)))
+ return;
+
+ /* Ensure timer is disabled */
+ writel(0, base + TIMER_CTRL);
+
+ if (init_count == 2 || !of_device_is_available(np))
+ goto err;
+
+ if (!init_count)
+ __sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
+ else {
+ irq = irq_of_parse_and_map(np, 0);
+ if (irq <= 0)
+ goto err;
+
+ __sp804_clockevents_init(base, irq, clk, name);
+ }
+
+ init_count++;
+ return;
+err:
+ iounmap(base);
+}
+CLOCKSOURCE_OF_DECLARE(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);