clocksource/drivers/rda: Add clock driver for RDA8810PL SoC

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>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index a4ae339..a9e26f6 100644 (file)
--- 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 f475927..cdd210f 100644 (file)
--- 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 (file)
index 0000000..fd1199c
--- /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);