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Subject[PATCH v3 11/15] clocksource: Add clock driver for RDA8810PL SoC
Date
Add clock driver for RDA Micro RDA8810PL SoC supporting OSTIMER
and HWTIMER.

RDA8810PL has two independent timers: OSTIMER (56 bit) and HWTIMER
(64 bit). Each timer provides optional interrupt support. In this
driver, OSTIMER is used for clockevents and HWTIMER is used for
clocksource.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
arch/arm/mach-rda/Kconfig | 1 +
drivers/clocksource/Kconfig | 8 ++
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-rda.c | 195 ++++++++++++++++++++++++++++++++
4 files changed, 205 insertions(+)
create mode 100644 drivers/clocksource/timer-rda.c

diff --git a/arch/arm/mach-rda/Kconfig b/arch/arm/mach-rda/Kconfig
index 29012bc68ca4..1ea753f57b2d 100644
--- a/arch/arm/mach-rda/Kconfig
+++ b/arch/arm/mach-rda/Kconfig
@@ -4,5 +4,6 @@ menuconfig ARCH_RDA
select COMMON_CLK
select GENERIC_IRQ_CHIP
select RDA_INTC
+ select RDA_TIMER
help
This enables support for the RDA Micro 8810PL SoC family.
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 55c77e44bb2d..598b592e03d7 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -105,6 +105,14 @@ config OWL_TIMER
help
Enables the support for the Actions Semi Owl timer driver.

+config RDA_TIMER
+ bool "RDA timer driver" if COMPILE_TEST
+ depends on GENERIC_CLOCKEVENTS
+ select CLKSRC_MMIO
+ select TIMER_OF
+ help
+ Enables the support for the RDA Micro timer driver.
+
config SUN4I_TIMER
bool "Sun4i timer driver" if COMPILE_TEST
depends on HAS_IOMEM
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index dd9138104568..150020a90707 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_OXNAS_RPS_TIMER) += timer-oxnas-rps.o
obj-$(CONFIG_OWL_TIMER) += timer-owl.o
obj-$(CONFIG_SPRD_TIMER) += timer-sprd.o
obj-$(CONFIG_NPCM7XX_TIMER) += timer-npcm7xx.o
+obj-$(CONFIG_RDA_TIMER) += timer-rda.o

obj-$(CONFIG_ARC_TIMERS) += arc_timer.o
obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o
diff --git a/drivers/clocksource/timer-rda.c b/drivers/clocksource/timer-rda.c
new file mode 100644
index 000000000000..fd1199c189bf
--- /dev/null
+++ b/drivers/clocksource/timer-rda.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RDA8810PL SoC timer driver
+ *
+ * Copyright RDA Microelectronics Company Limited
+ * Copyright (c) 2017 Andreas Färber
+ * Copyright (c) 2018 Manivannan Sadhasivam
+ *
+ * RDA8810PL has two independent timers: OSTIMER (56 bit) and HWTIMER (64 bit).
+ * Each timer provides optional interrupt support. In this driver, OSTIMER is
+ * used for clockevents and HWTIMER is used for clocksource.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+
+#include "timer-of.h"
+
+#define RDA_OSTIMER_LOADVAL_L 0x000
+#define RDA_OSTIMER_CTRL 0x004
+#define RDA_HWTIMER_LOCKVAL_L 0x024
+#define RDA_HWTIMER_LOCKVAL_H 0x028
+#define RDA_TIMER_IRQ_MASK_SET 0x02c
+#define RDA_TIMER_IRQ_MASK_CLR 0x030
+#define RDA_TIMER_IRQ_CLR 0x034
+
+#define RDA_OSTIMER_CTRL_ENABLE BIT(24)
+#define RDA_OSTIMER_CTRL_REPEAT BIT(28)
+#define RDA_OSTIMER_CTRL_LOAD BIT(30)
+
+#define RDA_TIMER_IRQ_MASK_OSTIMER BIT(0)
+
+#define RDA_TIMER_IRQ_CLR_OSTIMER BIT(0)
+
+static int rda_ostimer_start(void __iomem *base, bool periodic, u64 cycles)
+{
+ u32 ctrl, load_l;
+
+ load_l = (u32)cycles;
+ ctrl = ((cycles >> 32) & 0xffffff);
+ ctrl |= RDA_OSTIMER_CTRL_LOAD | RDA_OSTIMER_CTRL_ENABLE;
+ if (periodic)
+ ctrl |= RDA_OSTIMER_CTRL_REPEAT;
+
+ /* Enable ostimer interrupt first */
+ writel_relaxed(RDA_TIMER_IRQ_MASK_OSTIMER,
+ base + RDA_TIMER_IRQ_MASK_SET);
+
+ /* Write low 32 bits first, high 24 bits are with ctrl */
+ writel_relaxed(load_l, base + RDA_OSTIMER_LOADVAL_L);
+ writel_relaxed(ctrl, base + RDA_OSTIMER_CTRL);
+
+ return 0;
+}
+
+static int rda_ostimer_stop(void __iomem *base)
+{
+ /* Disable ostimer interrupt first */
+ writel_relaxed(RDA_TIMER_IRQ_MASK_OSTIMER,
+ base + RDA_TIMER_IRQ_MASK_CLR);
+
+ writel_relaxed(0, base + RDA_OSTIMER_CTRL);
+
+ return 0;
+}
+
+static int rda_ostimer_set_state_shutdown(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+
+ rda_ostimer_stop(timer_of_base(to));
+
+ return 0;
+}
+
+static int rda_ostimer_set_state_oneshot(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+
+ rda_ostimer_stop(timer_of_base(to));
+
+ return 0;
+}
+
+static int rda_ostimer_set_state_periodic(struct clock_event_device *evt)
+{
+ struct timer_of *to = to_timer_of(evt);
+ unsigned long cycles_per_jiffy;
+
+ rda_ostimer_stop(timer_of_base(to));
+
+ cycles_per_jiffy = ((unsigned long long)NSEC_PER_SEC / HZ *
+ evt->mult) >> evt->shift;
+ rda_ostimer_start(timer_of_base(to), true, cycles_per_jiffy);
+
+ return 0;
+}
+
+static int rda_ostimer_tick_resume(struct clock_event_device *evt)
+{
+ return 0;
+}
+
+static int rda_ostimer_set_next_event(unsigned long evt,
+ struct clock_event_device *ev)
+{
+ struct timer_of *to = to_timer_of(ev);
+
+ rda_ostimer_start(timer_of_base(to), false, evt);
+
+ return 0;
+}
+
+static irqreturn_t rda_ostimer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+ struct timer_of *to = to_timer_of(evt);
+
+ /* clear timer int */
+ writel_relaxed(RDA_TIMER_IRQ_CLR_OSTIMER,
+ timer_of_base(to) + RDA_TIMER_IRQ_CLR);
+
+ if (evt->event_handler)
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct timer_of rda_ostimer_of = {
+ .flags = TIMER_OF_IRQ | TIMER_OF_BASE,
+
+ .clkevt = {
+ .name = "rda-ostimer",
+ .rating = 250,
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
+ CLOCK_EVT_FEAT_DYNIRQ,
+ .set_state_shutdown = rda_ostimer_set_state_shutdown,
+ .set_state_oneshot = rda_ostimer_set_state_oneshot,
+ .set_state_periodic = rda_ostimer_set_state_periodic,
+ .tick_resume = rda_ostimer_tick_resume,
+ .set_next_event = rda_ostimer_set_next_event,
+ },
+
+ .of_base = {
+ .name = "rda-timer",
+ .index = 0,
+ },
+
+ .of_irq = {
+ .name = "ostimer",
+ .handler = rda_ostimer_interrupt,
+ .flags = IRQF_TIMER,
+ },
+};
+
+static u64 rda_hwtimer_read(struct clocksource *cs)
+{
+ void __iomem *base = timer_of_base(&rda_ostimer_of);
+ u32 lo, hi;
+
+ /* Always read low 32 bits first */
+ do {
+ lo = readl_relaxed(base + RDA_HWTIMER_LOCKVAL_L);
+ hi = readl_relaxed(base + RDA_HWTIMER_LOCKVAL_H);
+ } while (hi != readl_relaxed(base + RDA_HWTIMER_LOCKVAL_H));
+
+ return ((u64)hi << 32) | lo;
+}
+
+static struct clocksource rda_hwtimer_clocksource = {
+ .name = "rda-timer",
+ .rating = 400,
+ .read = rda_hwtimer_read,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init rda_timer_init(struct device_node *np)
+{
+ unsigned long rate = 2000000;
+ int ret;
+
+ ret = timer_of_init(np, &rda_ostimer_of);
+ if (ret)
+ return ret;
+
+ clocksource_register_hz(&rda_hwtimer_clocksource, rate);
+
+ clockevents_config_and_register(&rda_ostimer_of.clkevt, rate,
+ 0x2, UINT_MAX);
+
+ return 0;
+}
+
+TIMER_OF_DECLARE(rda8810pl, "rda,8810pl-timer", rda_timer_init);
--
2.17.1
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