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From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Sekhar Nori <nsekhar@ti.com>, Kevin Hilman <khilman@kernel.org>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	David Lechner <david@lechnology.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [RFC v2 2/2] clocksource: timer-davinci: add support for clocksource
Date: Thu, 23 May 2019 14:58:13 +0200	[thread overview]
Message-ID: <20190523125813.29506-3-brgl@bgdev.pl> (raw)
In-Reply-To: <20190523125813.29506-1-brgl@bgdev.pl>

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Extend the davinci-timer driver to also register a clock source.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/clocksource/timer-davinci.c | 70 +++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/drivers/clocksource/timer-davinci.c b/drivers/clocksource/timer-davinci.c
index a8fc7b3805c9..c478991da253 100644
--- a/drivers/clocksource/timer-davinci.c
+++ b/drivers/clocksource/timer-davinci.c
@@ -42,6 +42,8 @@
 #define DAVINCI_TIMER_MIN_DELTA			0x01
 #define DAVINCI_TIMER_MAX_DELTA			0xfffffffe
 
+#define DAVINCI_TIMER_CLKSRC_BITS		32
+
 #define DAVINCI_TIMER_TGCR_DEFAULT \
 		(DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED | DAVINCI_TIMER_UNRESET)
 
@@ -61,6 +63,16 @@ struct davinci_clockevent {
 	unsigned int enamode_mask;
 };
 
+/*
+ * This must be globally accessible by davinci_timer_read_sched_clock(), so
+ * let's keep it here.
+ */
+static struct {
+	struct clocksource dev;
+	void __iomem *base;
+	unsigned int tim_off;
+} davinci_clocksource;
+
 static struct davinci_clockevent *
 to_davinci_clockevent(struct clock_event_device *clockevent)
 {
@@ -159,6 +171,32 @@ static irqreturn_t davinci_timer_irq_timer(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static u64 notrace davinci_timer_read_sched_clock(void)
+{
+	return readl_relaxed(davinci_clocksource.base +
+			     davinci_clocksource.tim_off);
+}
+
+static u64 davinci_clocksource_read(struct clocksource *dev)
+{
+	return davinci_timer_read_sched_clock();
+}
+
+static void davinci_clocksource_init(void __iomem *base, unsigned int tim_off,
+				     unsigned int prd_off, unsigned int shift)
+{
+	davinci_tcr_update(base,
+			   DAVINCI_TIMER_ENAMODE_MASK << shift,
+			   DAVINCI_TIMER_ENAMODE_DISABLED << shift);
+
+	writel_relaxed(0x0, base + tim_off);
+	writel_relaxed(UINT_MAX, base + prd_off);
+
+	davinci_tcr_update(base,
+			   DAVINCI_TIMER_ENAMODE_MASK << shift,
+			   DAVINCI_TIMER_ENAMODE_ONESHOT << shift);
+}
+
 static void davinci_timer_init(void __iomem *base)
 {
 	/* Set clock to internal mode and disable it. */
@@ -248,6 +286,38 @@ int __init davinci_timer_register(struct clk *clk,
 					DAVINCI_TIMER_MIN_DELTA,
 					DAVINCI_TIMER_MAX_DELTA);
 
+	davinci_clocksource.dev.rating = 300;
+	davinci_clocksource.dev.read = davinci_clocksource_read;
+	davinci_clocksource.dev.mask =
+			CLOCKSOURCE_MASK(DAVINCI_TIMER_CLKSRC_BITS);
+	davinci_clocksource.dev.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+	davinci_clocksource.base = base;
+
+	if (timer_cfg->cmp_off) {
+		davinci_clocksource.dev.name = "tim12";
+		davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM12;
+		davinci_clocksource_init(base,
+					 DAVINCI_TIMER_REG_TIM12,
+					 DAVINCI_TIMER_REG_PRD12,
+					 DAVINCI_TIMER_ENAMODE_SHIFT_TIM12);
+	} else {
+		davinci_clocksource.dev.name = "tim34";
+		davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM34;
+		davinci_clocksource_init(base,
+					 DAVINCI_TIMER_REG_TIM34,
+					 DAVINCI_TIMER_REG_PRD34,
+					 DAVINCI_TIMER_ENAMODE_SHIFT_TIM34);
+	}
+
+	rv = clocksource_register_hz(&davinci_clocksource.dev, tick_rate);
+	if (rv) {
+		pr_err("Unable to register clocksource");
+		return rv;
+	}
+
+	sched_clock_register(davinci_timer_read_sched_clock,
+			     DAVINCI_TIMER_CLKSRC_BITS, tick_rate);
+
 	return 0;
 }
 
-- 
2.21.0


      parent reply	other threads:[~2019-05-23 12:58 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23 12:58 [RFC v2 0/2] clocksource: davinci-timer: new driver Bartosz Golaszewski
2019-05-23 12:58 ` [RFC v2 1/2] clocksource: davinci-timer: add support for clockevents Bartosz Golaszewski
2019-05-23 16:38   ` Daniel Lezcano
2019-05-24  7:28     ` Bartosz Golaszewski
2019-05-24  8:59       ` Daniel Lezcano
2019-05-24 11:53         ` Bartosz Golaszewski
2019-05-25 14:16           ` Daniel Lezcano
2019-05-26  8:16             ` Bartosz Golaszewski
2019-05-31 12:21               ` Bartosz Golaszewski
2019-05-23 12:58 ` Bartosz Golaszewski [this message]

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