On 19/11/2018 17:09, Manivannan Sadhasivam wrote: > Add clock driver for RDA Micro RDA8810PL SoC supporting OSTIMER > and HWTIMER. > > Signed-off-by: Andreas Färber <afaerber@xxxxxxx> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> > --- > arch/arm/mach-rda/Kconfig | 1 + > drivers/clocksource/Kconfig | 7 ++ > drivers/clocksource/Makefile | 1 + > drivers/clocksource/timer-rda.c | 187 ++++++++++++++++++++++++++++++++ > 4 files changed, 196 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..f51eee3a72ea 100644 > --- a/drivers/clocksource/Kconfig > +++ b/drivers/clocksource/Kconfig > @@ -105,6 +105,13 @@ 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 > + 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..3aa684d92c5d > --- /dev/null > +++ b/drivers/clocksource/timer-rda.c > @@ -0,0 +1,187 @@ > +// 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 > + */ > + > +#include <linux/clockchips.h> > +#include <linux/interrupt.h> > +#include <linux/irq.h> > +#include <linux/irqreturn.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/of_irq.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_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_SET_OSTIMER BIT(0) > + > +#define RDA_TIMER_IRQ_CLR_OSTIMER BIT(0) > + > +static void __iomem *rda_timer_base; > + > +static u64 rda_hwtimer_read(struct clocksource *cs) > +{ > + u32 lo, hi; > + > + /* Always read low 32 bits first */ > + lo = readl(rda_timer_base + RDA_HWTIMER_LOCKVAL_L); > + hi = readl(rda_timer_base + RDA_HWTIMER_LOCKVAL_H); Please use the relaxed accessors throughout this driver. There is zero reason to use the non-relaxed versions here. Now, I'm pretty sure this thing isn't correct. <timer = 0x00000000ffffffff> lo = 0xffffffff; <tick, timer = 0x0000000100000000> hi = 0x00000001; Bingo. You cannot read a 64bit counter with only two 32bit accesses. > + > + return ((u64)hi << 32) | lo; > +} > + > +static struct clocksource rda_clocksource = { > + .name = "rda-timer", > + .rating = 400, > + .read = rda_hwtimer_read, > + .mask = CLOCKSOURCE_MASK(64), This is a 64bit counter? See below. > + .flags = CLOCK_SOURCE_IS_CONTINUOUS, > +}; > + > +static int rda_ostimer_start(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(RDA_TIMER_IRQ_MASK_SET_OSTIMER, > + rda_timer_base + RDA_TIMER_IRQ_MASK_SET); Is it masking or enabling the interrupt? > + > + /* Write low 32 bits first, high 24 bits are with ctrl */ You're saying that you can only write 56 bits? This contradicts the 64bt counter thing above. > + writel(load_l, rda_timer_base + RDA_OSTIMER_LOADVAL_L); > + writel(ctrl, rda_timer_base + RDA_OSTIMER_CTRL); > + > + return 0; > +} > + > +static int rda_ostimer_stop(void) > +{ > + /* Disable ostimer interrupt first */ > + writel(0, rda_timer_base + RDA_TIMER_IRQ_MASK_SET); > + > + writel(0, rda_timer_base + RDA_OSTIMER_CTRL); > + > + return 0; > +} > + > +static int rda_ostimer_set_state_shutdown(struct clock_event_device *evt) > +{ > + rda_ostimer_stop(); > + > + return 0; > +} > + > +static int rda_ostimer_set_state_oneshot(struct clock_event_device *evt) > +{ > + rda_ostimer_stop(); > + > + return 0; > +} > + > +static int rda_ostimer_set_state_periodic(struct clock_event_device *evt) > +{ > + unsigned long cycles_per_jiffy; > + > + rda_ostimer_stop(); > + > + cycles_per_jiffy = ((unsigned long long)NSEC_PER_SEC / HZ * > + evt->mult) >> evt->shift; > + rda_ostimer_start(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) > +{ > + rda_ostimer_start(false, evt); > + > + return 0; > +} > + > +static struct clock_event_device rda_clockevent = { > + .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, > +}; > + > +static irqreturn_t rda_ostimer_interrupt(int irq, void *dev_id) > +{ > + struct clock_event_device *evt = dev_id; > + > + /* clear timer int */ > + writel(RDA_TIMER_IRQ_CLR_OSTIMER, rda_timer_base + RDA_TIMER_IRQ_CLR); > + > + if (evt->event_handler) > + evt->event_handler(evt); > + > + return IRQ_HANDLED; > +} > + > +static int __init rda_timer_init(struct device_node *node) > +{ > + unsigned long rate = 2000000; > + int ostimer_irq, ret; > + > + rda_timer_base = of_io_request_and_map(node, 0, "rda-timer"); > + if (IS_ERR(rda_timer_base)) { > + pr_err("Can't map timer registers"); > + return PTR_ERR(rda_timer_base); > + } > + > + ostimer_irq = of_irq_get_byname(node, "ostimer"); > + if (ostimer_irq <= 0) { > + pr_err("Can't parse ostimer IRQ"); > + return -EINVAL; Leaking IO space. > + } > + > + clocksource_register_hz(&rda_clocksource, rate); > + > + ret = request_irq(ostimer_irq, rda_ostimer_interrupt, IRQF_TIMER, > + "rda-ostimer", &rda_clockevent); > + if (ret) { > + pr_err("failed to request irq %d\n", ostimer_irq); > + return ret; Same here. > + } > + > + irq_force_affinity(ostimer_irq, cpumask_of(0)); Why? > + > + rda_clockevent.cpumask = cpumask_of(0); > + rda_clockevent.irq = ostimer_irq; > + clockevents_config_and_register(&rda_clockevent, rate, > + 0x2, 0xffffffff); > + > + return 0; > +} > + > +TIMER_OF_DECLARE(rda8810pl, "rda,8810pl-timer", rda_timer_init); > Thanks, M. -- Jazz is not dead. It just smells funny...