1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-digicolor.c b/drivers/clocksource/timer-digicolor.c
new file mode 100644
index 000000000..1e984a4d8
--- /dev/null
+++ b/drivers/clocksource/timer-digicolor.c
@@ -0,0 +1,207 @@
+/*
+ * Conexant Digicolor timer driver
+ *
+ * Author: Baruch Siach <baruch@tkos.co.il>
+ *
+ * Copyright (C) 2014 Paradox Innovation Ltd.
+ *
+ * Based on:
+ *	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.
+ */
+
+/*
+ * Conexant Digicolor SoCs have 8 configurable timers, named from "Timer A" to
+ * "Timer H". Timer A is the only one with watchdog support, so it is dedicated
+ * to the watchdog driver. This driver uses Timer B for sched_clock(), and
+ * Timer C for clockevents.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqreturn.h>
+#include <linux/sched/clock.h>
+#include <linux/sched_clock.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+enum {
+	TIMER_A,
+	TIMER_B,
+	TIMER_C,
+	TIMER_D,
+	TIMER_E,
+	TIMER_F,
+	TIMER_G,
+	TIMER_H,
+};
+
+#define CONTROL(t)	((t)*8)
+#define COUNT(t)	((t)*8 + 4)
+
+#define CONTROL_DISABLE		0
+#define CONTROL_ENABLE		BIT(0)
+#define CONTROL_MODE(m)		((m) << 4)
+#define CONTROL_MODE_ONESHOT	CONTROL_MODE(1)
+#define CONTROL_MODE_PERIODIC	CONTROL_MODE(2)
+
+struct digicolor_timer {
+	struct clock_event_device ce;
+	void __iomem *base;
+	u32 ticks_per_jiffy;
+	int timer_id; /* one of TIMER_* */
+};
+
+static struct digicolor_timer *dc_timer(struct clock_event_device *ce)
+{
+	return container_of(ce, struct digicolor_timer, ce);
+}
+
+static inline void dc_timer_disable(struct clock_event_device *ce)
+{
+	struct digicolor_timer *dt = dc_timer(ce);
+	writeb(CONTROL_DISABLE, dt->base + CONTROL(dt->timer_id));
+}
+
+static inline void dc_timer_enable(struct clock_event_device *ce, u32 mode)
+{
+	struct digicolor_timer *dt = dc_timer(ce);
+	writeb(CONTROL_ENABLE | mode, dt->base + CONTROL(dt->timer_id));
+}
+
+static inline void dc_timer_set_count(struct clock_event_device *ce,
+				      unsigned long count)
+{
+	struct digicolor_timer *dt = dc_timer(ce);
+	writel(count, dt->base + COUNT(dt->timer_id));
+}
+
+static int digicolor_clkevt_shutdown(struct clock_event_device *ce)
+{
+	dc_timer_disable(ce);
+	return 0;
+}
+
+static int digicolor_clkevt_set_oneshot(struct clock_event_device *ce)
+{
+	dc_timer_disable(ce);
+	dc_timer_enable(ce, CONTROL_MODE_ONESHOT);
+	return 0;
+}
+
+static int digicolor_clkevt_set_periodic(struct clock_event_device *ce)
+{
+	struct digicolor_timer *dt = dc_timer(ce);
+
+	dc_timer_disable(ce);
+	dc_timer_set_count(ce, dt->ticks_per_jiffy);
+	dc_timer_enable(ce, CONTROL_MODE_PERIODIC);
+	return 0;
+}
+
+static int digicolor_clkevt_next_event(unsigned long evt,
+				       struct clock_event_device *ce)
+{
+	dc_timer_disable(ce);
+	dc_timer_set_count(ce, evt);
+	dc_timer_enable(ce, CONTROL_MODE_ONESHOT);
+
+	return 0;
+}
+
+static struct digicolor_timer dc_timer_dev = {
+	.ce = {
+		.name = "digicolor_tick",
+		.rating = 340,
+		.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+		.set_state_shutdown = digicolor_clkevt_shutdown,
+		.set_state_periodic = digicolor_clkevt_set_periodic,
+		.set_state_oneshot = digicolor_clkevt_set_oneshot,
+		.tick_resume = digicolor_clkevt_shutdown,
+		.set_next_event = digicolor_clkevt_next_event,
+	},
+	.timer_id = TIMER_C,
+};
+
+static irqreturn_t digicolor_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static u64 notrace digicolor_timer_sched_read(void)
+{
+	return ~readl(dc_timer_dev.base + COUNT(TIMER_B));
+}
+
+static int __init digicolor_timer_init(struct device_node *node)
+{
+	unsigned long rate;
+	struct clk *clk;
+	int ret, irq;
+
+	/*
+	 * timer registers are shared with the watchdog timer;
+	 * don't map exclusively
+	 */
+	dc_timer_dev.base = of_iomap(node, 0);
+	if (!dc_timer_dev.base) {
+		pr_err("Can't map registers\n");
+		return -ENXIO;
+	}
+
+	irq = irq_of_parse_and_map(node, dc_timer_dev.timer_id);
+	if (irq <= 0) {
+		pr_err("Can't parse IRQ\n");
+		return -EINVAL;
+	}
+
+	clk = of_clk_get(node, 0);
+	if (IS_ERR(clk)) {
+		pr_err("Can't get timer clock\n");
+		return PTR_ERR(clk);
+	}
+	clk_prepare_enable(clk);
+	rate = clk_get_rate(clk);
+	dc_timer_dev.ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);
+
+	writeb(CONTROL_DISABLE, dc_timer_dev.base + CONTROL(TIMER_B));
+	writel(UINT_MAX, dc_timer_dev.base + COUNT(TIMER_B));
+	writeb(CONTROL_ENABLE, dc_timer_dev.base + CONTROL(TIMER_B));
+
+	sched_clock_register(digicolor_timer_sched_read, 32, rate);
+	clocksource_mmio_init(dc_timer_dev.base + COUNT(TIMER_B), node->name,
+			      rate, 340, 32, clocksource_mmio_readl_down);
+
+	ret = request_irq(irq, digicolor_timer_interrupt,
+			  IRQF_TIMER | IRQF_IRQPOLL, "digicolor_timerC",
+			  &dc_timer_dev.ce);
+	if (ret) {
+		pr_warn("request of timer irq %d failed (%d)\n", irq, ret);
+		return ret;
+	}
+
+	dc_timer_dev.ce.cpumask = cpu_possible_mask;
+	dc_timer_dev.ce.irq = irq;
+
+	clockevents_config_and_register(&dc_timer_dev.ce, rate, 0, 0xffffffff);
+
+	return 0;
+}
+TIMER_OF_DECLARE(conexant_digicolor, "cnxt,cx92755-timer",
+		       digicolor_timer_init);