--- /dev/null
+/*
+ * Allwinner SoCs hstimer driver.
+ *
+ * Copyright (C) 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqreturn.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define TIMER_IRQ_EN_REG 0x00
+#define TIMER_IRQ_EN(val) BIT(val)
+#define TIMER_IRQ_ST_REG 0x04
+#define TIMER_CTL_REG(val) (0x20 * (val) + 0x10)
+#define TIMER_CTL_ENABLE BIT(0)
+#define TIMER_CTL_RELOAD BIT(1)
+#define TIMER_CTL_CLK_PRES(val) (((val) & 0x7) << 4)
+#define TIMER_CTL_ONESHOT BIT(7)
+#define TIMER_INTVAL_LO_REG(val) (0x20 * (val) + 0x14)
+#define TIMER_INTVAL_HI_REG(val) (0x20 * (val) + 0x18)
+#define TIMER_CNTVAL_LO_REG(val) (0x20 * (val) + 0x1c)
+#define TIMER_CNTVAL_HI_REG(val) (0x20 * (val) + 0x20)
+
+#define TIMER_SYNC_TICKS 3
+
+struct sun5i_timer {
+ void __iomem *base;
+ struct clk *clk;
+ struct notifier_block clk_rate_cb;
+ u32 ticks_per_jiffy;
+};
+
+#define to_sun5i_timer(x) \
+ container_of(x, struct sun5i_timer, clk_rate_cb)
+
+struct sun5i_timer_clksrc {
+ struct sun5i_timer timer;
+ struct clocksource clksrc;
+};
+
+#define to_sun5i_timer_clksrc(x) \
+ container_of(x, struct sun5i_timer_clksrc, clksrc)
+
+struct sun5i_timer_clkevt {
+ struct sun5i_timer timer;
+ struct clock_event_device clkevt;
+};
+
+#define to_sun5i_timer_clkevt(x) \
+ container_of(x, struct sun5i_timer_clkevt, clkevt)
+
+/*
+ * When we disable a timer, we need to wait at least for 2 cycles of
+ * the timer source clock. We will use for that the clocksource timer
+ * that is already setup and runs at the same frequency than the other
+ * timers, and we never will be disabled.
+ */
+static void sun5i_clkevt_sync(struct sun5i_timer_clkevt *ce)
+{
+ u32 old = readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1));
+
+ while ((old - readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1))) < TIMER_SYNC_TICKS)
+ cpu_relax();
+}
+
+static void sun5i_clkevt_time_stop(struct sun5i_timer_clkevt *ce, u8 timer)
+{
+ u32 val = readl(ce->timer.base + TIMER_CTL_REG(timer));
+ writel(val & ~TIMER_CTL_ENABLE, ce->timer.base + TIMER_CTL_REG(timer));
+
+ sun5i_clkevt_sync(ce);
+}
+
+static void sun5i_clkevt_time_setup(struct sun5i_timer_clkevt *ce, u8 timer, u32 delay)
+{
+ writel(delay, ce->timer.base + TIMER_INTVAL_LO_REG(timer));
+}
+
+static void sun5i_clkevt_time_start(struct sun5i_timer_clkevt *ce, u8 timer, bool periodic)
+{
+ u32 val = readl(ce->timer.base + TIMER_CTL_REG(timer));
+
+ if (periodic)
+ val &= ~TIMER_CTL_ONESHOT;
+ else
+ val |= TIMER_CTL_ONESHOT;
+
+ writel(val | TIMER_CTL_ENABLE | TIMER_CTL_RELOAD,
+ ce->timer.base + TIMER_CTL_REG(timer));
+}
+
+static void sun5i_clkevt_mode(enum clock_event_mode mode,
+ struct clock_event_device *clkevt)
+{
+ struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ sun5i_clkevt_time_stop(ce, 0);
+ sun5i_clkevt_time_setup(ce, 0, ce->timer.ticks_per_jiffy);
+ sun5i_clkevt_time_start(ce, 0, true);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ sun5i_clkevt_time_stop(ce, 0);
+ sun5i_clkevt_time_start(ce, 0, false);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ default:
+ sun5i_clkevt_time_stop(ce, 0);
+ break;
+ }
+}
+
+static int sun5i_clkevt_next_event(unsigned long evt,
+ struct clock_event_device *clkevt)
+{
+ struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt);
+
+ sun5i_clkevt_time_stop(ce, 0);
+ sun5i_clkevt_time_setup(ce, 0, evt - TIMER_SYNC_TICKS);
+ sun5i_clkevt_time_start(ce, 0, false);
+
+ return 0;
+}
+
+static irqreturn_t sun5i_timer_interrupt(int irq, void *dev_id)
+{
+ struct sun5i_timer_clkevt *ce = (struct sun5i_timer_clkevt *)dev_id;
+
+ writel(0x1, ce->timer.base + TIMER_IRQ_ST_REG);
+ ce->clkevt.event_handler(&ce->clkevt);
+
+ return IRQ_HANDLED;
+}
+
+static cycle_t sun5i_clksrc_read(struct clocksource *clksrc)
+{
+ struct sun5i_timer_clksrc *cs = to_sun5i_timer_clksrc(clksrc);
+
+ return ~readl(cs->timer.base + TIMER_CNTVAL_LO_REG(1));
+}
+
+static int sun5i_rate_cb_clksrc(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct sun5i_timer *timer = to_sun5i_timer(nb);
+ struct sun5i_timer_clksrc *cs = container_of(timer, struct sun5i_timer_clksrc, timer);
+
+ switch (event) {
+ case PRE_RATE_CHANGE:
+ clocksource_unregister(&cs->clksrc);
+ break;
+
+ case POST_RATE_CHANGE:
+ clocksource_register_hz(&cs->clksrc, ndata->new_rate);
+ break;
+
+ default:
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int __init sun5i_setup_clocksource(struct device_node *node,
+ void __iomem *base,
+ struct clk *clk, int irq)
+{
+ struct sun5i_timer_clksrc *cs;
+ unsigned long rate;
+ int ret;
+
+ cs = kzalloc(sizeof(*cs), GFP_KERNEL);
+ if (!cs)
+ return -ENOMEM;
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("Couldn't enable parent clock\n");
+ goto err_free;
+ }
+
+ rate = clk_get_rate(clk);
+
+ cs->timer.base = base;
+ cs->timer.clk = clk;
+ cs->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clksrc;
+ cs->timer.clk_rate_cb.next = NULL;
+
+ ret = clk_notifier_register(clk, &cs->timer.clk_rate_cb);
+ if (ret) {
+ pr_err("Unable to register clock notifier.\n");
+ goto err_disable_clk;
+ }
+
+ writel(~0, base + TIMER_INTVAL_LO_REG(1));
+ writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD,
+ base + TIMER_CTL_REG(1));
+
+ cs->clksrc.name = node->name;
+ cs->clksrc.rating = 340;
+ cs->clksrc.read = sun5i_clksrc_read;
+ cs->clksrc.mask = CLOCKSOURCE_MASK(32);
+ cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+ ret = clocksource_register_hz(&cs->clksrc, rate);
+ if (ret) {
+ pr_err("Couldn't register clock source.\n");
+ goto err_remove_notifier;
+ }
+
+ return 0;
+
+err_remove_notifier:
+ clk_notifier_unregister(clk, &cs->timer.clk_rate_cb);
+err_disable_clk:
+ clk_disable_unprepare(clk);
+err_free:
+ kfree(cs);
+ return ret;
+}
+
+static int sun5i_rate_cb_clkevt(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct sun5i_timer *timer = to_sun5i_timer(nb);
+ struct sun5i_timer_clkevt *ce = container_of(timer, struct sun5i_timer_clkevt, timer);
+
+ if (event == POST_RATE_CHANGE) {
+ clockevents_update_freq(&ce->clkevt, ndata->new_rate);
+ ce->timer.ticks_per_jiffy = DIV_ROUND_UP(ndata->new_rate, HZ);
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int __init sun5i_setup_clockevent(struct device_node *node, void __iomem *base,
+ struct clk *clk, int irq)
+{
+ struct sun5i_timer_clkevt *ce;
+ unsigned long rate;
+ int ret;
+ u32 val;
+
+ ce = kzalloc(sizeof(*ce), GFP_KERNEL);
+ if (!ce)
+ return -ENOMEM;
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("Couldn't enable parent clock\n");
+ goto err_free;
+ }
+
+ rate = clk_get_rate(clk);
+
+ ce->timer.base = base;
+ ce->timer.ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);
+ ce->timer.clk = clk;
+ ce->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clkevt;
+ ce->timer.clk_rate_cb.next = NULL;
+
+ ret = clk_notifier_register(clk, &ce->timer.clk_rate_cb);
+ if (ret) {
+ pr_err("Unable to register clock notifier.\n");
+ goto err_disable_clk;
+ }
+
+ ce->clkevt.name = node->name;
+ ce->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+ ce->clkevt.set_next_event = sun5i_clkevt_next_event;
+ ce->clkevt.set_mode = sun5i_clkevt_mode;
+ ce->clkevt.rating = 340;
+ ce->clkevt.irq = irq;
+ ce->clkevt.cpumask = cpu_possible_mask;
+
+ /* Enable timer0 interrupt */
+ val = readl(base + TIMER_IRQ_EN_REG);
+ writel(val | TIMER_IRQ_EN(0), base + TIMER_IRQ_EN_REG);
+
+ clockevents_config_and_register(&ce->clkevt, rate,
+ TIMER_SYNC_TICKS, 0xffffffff);
+
+ ret = request_irq(irq, sun5i_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
+ "sun5i_timer0", ce);
+ if (ret) {
+ pr_err("Unable to register interrupt\n");
+ goto err_remove_notifier;
+ }
+
+ return 0;
+
+err_remove_notifier:
+ clk_notifier_unregister(clk, &ce->timer.clk_rate_cb);
+err_disable_clk:
+ clk_disable_unprepare(clk);
+err_free:
+ kfree(ce);
+ return ret;
+}
+
+static void __init sun5i_timer_init(struct device_node *node)
+{
+ struct reset_control *rstc;
+ void __iomem *timer_base;
+ struct clk *clk;
+ int irq;
+
+ timer_base = of_io_request_and_map(node, 0, of_node_full_name(node));
+ if (!timer_base)
+ panic("Can't map registers");
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0)
+ panic("Can't parse IRQ");
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk))
+ panic("Can't get timer clock");
+
+ rstc = of_reset_control_get(node, NULL);
+ if (!IS_ERR(rstc))
+ reset_control_deassert(rstc);
+
+ sun5i_setup_clocksource(node, timer_base, clk, irq);
+ sun5i_setup_clockevent(node, timer_base, clk, irq);
+}
+CLOCKSOURCE_OF_DECLARE(sun5i_a13, "allwinner,sun5i-a13-hstimer",
+ sun5i_timer_init);
+CLOCKSOURCE_OF_DECLARE(sun7i_a20, "allwinner,sun7i-a20-hstimer",
+ sun5i_timer_init);
Code Review / kvmfornfv.git / blobdiff