Hi Guo,
On 18/03/2018 20:51, Guo Ren wrote:
This patch is a new driver. Please add the hardware details of this
timer and optionally a link to the documentation. No need to write a
book, just a quick summary of it.
> Signed-off-by: Guo Ren <ren_...@c-sky.com>
> ---
> drivers/clocksource/Makefile | 1 +
> drivers/clocksource/timer-nationalchip.c | 149
> +++++++++++++++++++++++++++++++
> 2 files changed, 150 insertions(+)
> create mode 100644 drivers/clocksource/timer-nationalchip.c
>
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index d6dec44..d091712 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -76,3 +76,4 @@ obj-$(CONFIG_H8300_TMR16) += h8300_timer16.o
> obj-$(CONFIG_H8300_TPU) += h8300_tpu.o
> obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o
> obj-$(CONFIG_X86_NUMACHIP) += numachip.o
> +obj-$(CONFIG_CSKY) += timer-nationalchip.o
> diff --git a/drivers/clocksource/timer-nationalchip.c
> b/drivers/clocksource/timer-nationalchip.c
> new file mode 100644
> index 0000000..1279d64
> --- /dev/null
> +++ b/drivers/clocksource/timer-nationalchip.c
> @@ -0,0 +1,149 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2018 Hangzhou NationalChip Science & Technology Co.,Ltd.
> +#include <linux/kernel.h>
> +#include <linux/sched.h>
> +#include <linux/param.h>
sched ? param ?
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/profile.h>
profile ?
> +#include <linux/irq.h>
> +#include <linux/rtc.h>
> +#include <linux/sizes.h>
rtc ? sizes ?
> +#include <linux/clocksource.h>
> +#include <linux/clockchips.h>
> +#include <asm/irq.h>
> +#include <asm/io.h>
> +#include <asm/delay.h>
Is the delay API defined for this architecture ? I don't see it used below.
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/sched_clock.h>
> +
> +#define NC_VA_COUNTER_1_STATUS (void *)(timer_reg + 0x00)
> +#define NC_VA_COUNTER_1_VALUE (void *)(timer_reg + 0x04)
> +#define NC_VA_COUNTER_1_CONTROL (void *)(timer_reg + 0x10)
> +#define NC_VA_COUNTER_1_CONFIG (void *)(timer_reg + 0x20)
> +#define NC_VA_COUNTER_1_PRE (void *)(timer_reg + 0x24)
> +#define NC_VA_COUNTER_1_INI (void *)(timer_reg + 0x28)
> +#define NC_VA_COUNTER_2_STATUS (void *)(timer_reg + 0x40)
> +#define NC_VA_COUNTER_2_VALUE (void *)(timer_reg + 0x44)
> +#define NC_VA_COUNTER_2_CONTROL (void *)(timer_reg + 0x50)
> +#define NC_VA_COUNTER_2_CONFIG (void *)(timer_reg + 0x60)
> +#define NC_VA_COUNTER_2_PRE (void *)(timer_reg + 0x64)
> +#define NC_VA_COUNTER_2_INI (void *)(timer_reg + 0x68)
> +#define NC_VA_COUNTER_3_STATUS (void *)(timer_reg + 0x80)
> +#define NC_VA_COUNTER_3_VALUE (void *)(timer_reg + 0x84)
> +#define NC_VA_COUNTER_3_CONTROL (void *)(timer_reg + 0x90)
> +#define NC_VA_COUNTER_3_CONFIG (void *)(timer_reg + 0xa0)
> +#define NC_VA_COUNTER_3_PRE (void *)(timer_reg + 0xa4)
> +#define NC_VA_COUNTER_3_INI (void *)(timer_reg + 0xa8)
> +
> +static unsigned int timer_reg;
> +
> +static inline void timer_reset(void)
> +{
> + __raw_writel(0x1, NC_VA_COUNTER_1_CONTROL);
> + __raw_writel(0x0, NC_VA_COUNTER_1_CONTROL);
> + __raw_writel(0x3, NC_VA_COUNTER_1_CONFIG);
> + __raw_writel(26, NC_VA_COUNTER_1_PRE);
Why are you using the __raw_writel instead of writel ?
No values, explicit macros please.
> +}
> +
> +static irqreturn_t timer_interrupt(int irq, void *dev_id)
timer_interrupt is a too generic name, at least nc_timer_interrupt would
be more accurate.
> +{
> + struct clock_event_device *dev = (struct clock_event_device *) dev_id;
> +
> + __raw_writel(1, NC_VA_COUNTER_1_STATUS);
> +
> + dev->event_handler(dev);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int nc_timer_set_periodic(struct clock_event_device *dev)
> +{
> + timer_reset();
> +
> + __raw_writel(0xFFFFD8EF, NC_VA_COUNTER_1_INI);
> + __raw_writel(0x2, NC_VA_COUNTER_1_CONTROL);
> +
> + return 0;
> +}
> +
> +static int nc_timer_set_next_event(unsigned long delta, struct
> clock_event_device *evt)
> +{
> + __raw_writel(0x1, NC_VA_COUNTER_1_CONTROL);
> + __raw_writel(ULONG_MAX - delta, NC_VA_COUNTER_1_INI);
> + __raw_writel(0x2, NC_VA_COUNTER_1_CONTROL);
> + return 0;
> +}
> +
> +static int nc_timer_shutdown(struct clock_event_device *dev)
> +{
> + __raw_writel(0x0, NC_VA_COUNTER_1_CONTROL);
> + __raw_writel(0x0, NC_VA_COUNTER_1_CONFIG);
> +
> + return 0;
> +}
> +
> +static struct clock_event_device nc_ced = {
> + .name = "nationalchip-clkevent",
> + .features = CLOCK_EVT_FEAT_PERIODIC
> + | CLOCK_EVT_FEAT_ONESHOT,
> + .rating = 200,
> + .set_state_shutdown = nc_timer_shutdown,
> + .set_state_periodic = nc_timer_set_periodic,
> + .set_next_event = nc_timer_set_next_event,
> +};
> +
> +static u64 notrace nc_sched_clock_read(void)
> +{
> + return (u64) __raw_readl(NC_VA_COUNTER_2_VALUE);
> +}
> +
> +static void nc_csd_enable(void)
Can you choose a more explicit name than 'csd'?
> +{
> + __raw_writel(0x1, NC_VA_COUNTER_2_CONTROL);
> + __raw_writel(0x0, NC_VA_COUNTER_2_CONTROL);
> + __raw_writel(0x1, NC_VA_COUNTER_2_CONFIG);
> +
> + __raw_writel(26,NC_VA_COUNTER_2_PRE);
> + __raw_writel(0, NC_VA_COUNTER_2_INI);
> + __raw_writel(0x2, NC_VA_COUNTER_2_CONTROL);
> +}
> +
> +static int __init nc_timer_init(struct device_node *np)
> +{
> + unsigned int irq;
> + unsigned int freq;
> +
> + /* parse from devicetree */
> + timer_reg = (unsigned int) of_iomap(np, 0);
> + if (!timer_reg)
> + panic("%s, of_iomap err.\n", __func__);
> +
> + irq = irq_of_parse_and_map(np, 0);
> + if (!irq)
> + panic("%s, irq_parse err.\n", __func__);
> +
> + if (of_property_read_u32(np, "clock-frequency", &freq))
> + panic("%s, clock-frequency error.\n", __func__);
>
> + pr_info("Nationalchip Timer Init, reg: %x, irq: %d, freq: %d.\n",
> + timer_reg, irq, freq);
> +
> + /* setup irq */
> + if (request_irq(irq, timer_interrupt, IRQF_TIMER, np->name, &nc_ced))
> + panic("%s timer_interrupt error.\n", __func__);
Replace the "clock-frequency" property to a clock phandle and use the
timer-of API.
That will result on something like that:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/timer-sprd.c#n124
No panic in init function.
> + /* register */
> + clockevents_config_and_register(&nc_ced, freq, 1, ULONG_MAX);
> +
> + nc_csd_enable();
> + clocksource_mmio_init(NC_VA_COUNTER_2_VALUE, "nationalchip-clksource",
> freq, 200, 32, clocksource_mmio_readl_up);
s/nationalchip-clksource/nationalchip/
line wrap
> + sched_clock_register(nc_sched_clock_read, 32, freq);
> +
> + return 0;
> +}
> +CLOCKSOURCE_OF_DECLARE(nc_timer, "nationalchip,timer-v1", nc_timer_init);
s/CLOCKSOURCE_OF_DECLARE/TIMER_OF_DECLARE/
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
