[PATCH 06/25] clocksource/drivers/meson6_timer: Use register names from the datasheet

[PATCH 06/25] clocksource/drivers/meson6_timer: Use register names from the datasheet

[Daniel Lezcano]

From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

This makes the driver use the names from S805 datasheet for the
preprocessor #defines. This makes it easier to spot that the driver
currently only supports Timer A (as clockevent with interrupt support)
and Timer E (as clocksource without interrupts). Timer B, C and D (which
are similar to Timer A) are currently not supported by the driver.

While here, this also removes the internal "CED_ID" and "CSD_ID" defines
which are used to identify the timer. These IDs are not described in the
datasheet and thus make it harder to compare the code to what's written
in the datasheet.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/meson6_timer.c | 108 +++++++++++++++++------------
 1 file changed, 64 insertions(+), 44 deletions(-)

diff --git a/drivers/clocksource/meson6_timer.c b/drivers/clocksource/meson6_timer.c
index 92f20991a937..23c7638e2bb3 100644
--- a/drivers/clocksource/meson6_timer.c
+++ b/drivers/clocksource/meson6_timer.c
@@ -10,6 +10,8 @@
  * warranty of any kind, whether express or implied.
  */
 
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
@@ -20,80 +22,96 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 
-#define CED_ID			0
-#define CSD_ID			4
-
-#define TIMER_ISA_MUX		0
-#define TIMER_ISA_VAL(t)	(((t) + 1) << 2)
-
-#define TIMER_INPUT_BIT(t)	(2 * (t))
-#define TIMER_ENABLE_BIT(t)	(16 + (t))
-#define TIMER_PERIODIC_BIT(t)	(12 + (t))
-
-#define TIMER_CED_INPUT_MASK	(3UL << TIMER_INPUT_BIT(CED_ID))
-#define TIMER_CSD_INPUT_MASK	(7UL << TIMER_INPUT_BIT(CSD_ID))
-
-#define TIMER_CED_UNIT_1US	0
-#define TIMER_CSD_UNIT_1US	1
+#define MESON_ISA_TIMER_MUX					0x00
+#define MESON_ISA_TIMER_MUX_TIMERD_EN				BIT(19)
+#define MESON_ISA_TIMER_MUX_TIMERC_EN				BIT(18)
+#define MESON_ISA_TIMER_MUX_TIMERB_EN				BIT(17)
+#define MESON_ISA_TIMER_MUX_TIMERA_EN				BIT(16)
+#define MESON_ISA_TIMER_MUX_TIMERD_MODE				BIT(15)
+#define MESON_ISA_TIMER_MUX_TIMERC_MODE				BIT(14)
+#define MESON_ISA_TIMER_MUX_TIMERB_MODE				BIT(13)
+#define MESON_ISA_TIMER_MUX_TIMERA_MODE				BIT(12)
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK		GENMASK(10, 8)
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_SYSTEM_CLOCK	0x0
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1US		0x1
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_10US		0x2
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_100US		0x3
+#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1MS		0x4
+#define MESON_ISA_TIMER_MUX_TIMERD_INPUT_CLOCK_MASK		GENMASK(7, 6)
+#define MESON_ISA_TIMER_MUX_TIMERC_INPUT_CLOCK_MASK		GENMASK(5, 4)
+#define MESON_ISA_TIMER_MUX_TIMERB_INPUT_CLOCK_MASK		GENMASK(3, 2)
+#define MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK		GENMASK(1, 0)
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1US		0x0
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_10US		0x1
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_100US		0x0
+#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1MS		0x3
+
+#define MESON_ISA_TIMERA					0x04
+#define MESON_ISA_TIMERB					0x08
+#define MESON_ISA_TIMERC					0x0c
+#define MESON_ISA_TIMERD					0x10
+#define MESON_ISA_TIMERE					0x14
 
 static void __iomem *timer_base;
 
 static u64 notrace meson6_timer_sched_read(void)
 {
-	return (u64)readl(timer_base + TIMER_ISA_VAL(CSD_ID));
+	return (u64)readl(timer_base + MESON_ISA_TIMERE);
 }
 
-static void meson6_clkevt_time_stop(unsigned char timer)
+static void meson6_clkevt_time_stop(void)
 {
-	u32 val = readl(timer_base + TIMER_ISA_MUX);
+	u32 val = readl(timer_base + MESON_ISA_TIMER_MUX);
 
-	writel(val & ~TIMER_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
+	writel(val & ~MESON_ISA_TIMER_MUX_TIMERA_EN,
+	       timer_base + MESON_ISA_TIMER_MUX);
 }
 
-static void meson6_clkevt_time_setup(unsigned char timer, unsigned long delay)
+static void meson6_clkevt_time_setup(unsigned long delay)
 {
-	writel(delay, timer_base + TIMER_ISA_VAL(timer));
+	writel(delay, timer_base + MESON_ISA_TIMERA);
 }
 
-static void meson6_clkevt_time_start(unsigned char timer, bool periodic)
+static void meson6_clkevt_time_start(bool periodic)
 {
-	u32 val = readl(timer_base + TIMER_ISA_MUX);
+	u32 val = readl(timer_base + MESON_ISA_TIMER_MUX);
 
 	if (periodic)
-		val |= TIMER_PERIODIC_BIT(timer);
+		val |= MESON_ISA_TIMER_MUX_TIMERA_MODE;
 	else
-		val &= ~TIMER_PERIODIC_BIT(timer);
+		val &= ~MESON_ISA_TIMER_MUX_TIMERA_MODE;
 
-	writel(val | TIMER_ENABLE_BIT(timer), timer_base + TIMER_ISA_MUX);
+	writel(val | MESON_ISA_TIMER_MUX_TIMERA_EN,
+	       timer_base + MESON_ISA_TIMER_MUX);
 }
 
 static int meson6_shutdown(struct clock_event_device *evt)
 {
-	meson6_clkevt_time_stop(CED_ID);
+	meson6_clkevt_time_stop();
 	return 0;
 }
 
 static int meson6_set_oneshot(struct clock_event_device *evt)
 {
-	meson6_clkevt_time_stop(CED_ID);
-	meson6_clkevt_time_start(CED_ID, false);
+	meson6_clkevt_time_stop();
+	meson6_clkevt_time_start(false);
 	return 0;
 }
 
 static int meson6_set_periodic(struct clock_event_device *evt)
 {
-	meson6_clkevt_time_stop(CED_ID);
-	meson6_clkevt_time_setup(CED_ID, USEC_PER_SEC / HZ - 1);
-	meson6_clkevt_time_start(CED_ID, true);
+	meson6_clkevt_time_stop();
+	meson6_clkevt_time_setup(USEC_PER_SEC / HZ - 1);
+	meson6_clkevt_time_start(true);
 	return 0;
 }
 
 static int meson6_clkevt_next_event(unsigned long evt,
 				    struct clock_event_device *unused)
 {
-	meson6_clkevt_time_stop(CED_ID);
-	meson6_clkevt_time_setup(CED_ID, evt);
-	meson6_clkevt_time_start(CED_ID, false);
+	meson6_clkevt_time_stop();
+	meson6_clkevt_time_setup(evt);
+	meson6_clkevt_time_start(false);
 
 	return 0;
 }
@@ -144,22 +162,24 @@ static int __init meson6_timer_init(struct device_node *node)
 	}
 
 	/* Set 1us for timer E */
-	val = readl(timer_base + TIMER_ISA_MUX);
-	val &= ~TIMER_CSD_INPUT_MASK;
-	val |= TIMER_CSD_UNIT_1US << TIMER_INPUT_BIT(CSD_ID);
-	writel(val, timer_base + TIMER_ISA_MUX);
+	val = readl(timer_base + MESON_ISA_TIMER_MUX);
+	val &= ~MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK;
+	val |= FIELD_PREP(MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK,
+			  MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1US);
+	writel(val, timer_base + MESON_ISA_TIMER_MUX);
 
 	sched_clock_register(meson6_timer_sched_read, 32, USEC_PER_SEC);
-	clocksource_mmio_init(timer_base + TIMER_ISA_VAL(CSD_ID), node->name,
+	clocksource_mmio_init(timer_base + MESON_ISA_TIMERE, node->name,
 			      1000 * 1000, 300, 32, clocksource_mmio_readl_up);
 
 	/* Timer A base 1us */
-	val &= ~TIMER_CED_INPUT_MASK;
-	val |= TIMER_CED_UNIT_1US << TIMER_INPUT_BIT(CED_ID);
-	writel(val, timer_base + TIMER_ISA_MUX);
+	val &= ~MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK;
+	val |= FIELD_PREP(MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK,
+			  MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1US);
+	writel(val, timer_base + MESON_ISA_TIMER_MUX);
 
 	/* Stop the timer A */
-	meson6_clkevt_time_stop(CED_ID);
+	meson6_clkevt_time_stop();
 
 	ret = setup_irq(irq, &meson6_timer_irq);
 	if (ret) {
-- 
2.17.1


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[PATCH 07/25] clocksource/drivers/meson6_timer: Implement the ARM delay timer

[Daniel Lezcano]

From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

Implement an ARM delay timer to be used for udelay(). This allows us to
skip the delay loop calibration at boot.

With this patch udelay() is now independent of CPU frequency changes.
This is a good thing on Meson8, Meson8b and Meson8m2 because changing
the CPU frequency requires running the CPU clock off the XTAL while
changing the PLL or it's dividers. After changing the CPU clocks we need
to wait a few usecs for the clock to become stable. So having an
udelay() implementation that doesn't depend on the CPU frequency is
beneficial.

Suggested-by: Jianxin Pan <jianxin.pan@amlogic.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 drivers/clocksource/meson6_timer.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/clocksource/meson6_timer.c b/drivers/clocksource/meson6_timer.c
index 23c7638e2bb3..84bd9479c3f8 100644
--- a/drivers/clocksource/meson6_timer.c
+++ b/drivers/clocksource/meson6_timer.c
@@ -22,6 +22,10 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 
+#ifdef CONFIG_ARM
+#include <linux/delay.h>
+#endif
+
 #define MESON_ISA_TIMER_MUX					0x00
 #define MESON_ISA_TIMER_MUX_TIMERD_EN				BIT(19)
 #define MESON_ISA_TIMER_MUX_TIMERC_EN				BIT(18)
@@ -54,6 +58,18 @@
 
 static void __iomem *timer_base;
 
+#ifdef CONFIG_ARM
+static unsigned long meson6_read_current_timer(void)
+{
+	return readl_relaxed(timer_base + MESON_ISA_TIMERE);
+}
+
+static struct delay_timer meson6_delay_timer = {
+	.read_current_timer = meson6_read_current_timer,
+	.freq = 1000 * 1000,
+};
+#endif
+
 static u64 notrace meson6_timer_sched_read(void)
 {
 	return (u64)readl(timer_base + MESON_ISA_TIMERE);
@@ -192,6 +208,12 @@ static int __init meson6_timer_init(struct device_node *node)
 
 	clockevents_config_and_register(&meson6_clockevent, USEC_PER_SEC,
 					1, 0xfffe);
+
+#ifdef CONFIG_ARM
+	/* Also use MESON_ISA_TIMERE for delays */
+	register_current_timer_delay(&meson6_delay_timer);
+#endif
+
 	return 0;
 }
 TIMER_OF_DECLARE(meson6, "amlogic,meson6-timer",
-- 
2.17.1


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