[PATCH v5 06/10] ARM: clocksource: add asm9260_timer driver
Matthias Brugger
matthias.bgg at gmail.com
Thu Oct 16 07:49:37 PDT 2014
Hi Oleksij,
2014-10-16 12:46 GMT+02:00 Oleksij Rempel <linux at rempel-privat.de>:
> Hi Matthias,
>
> of_io_request_and_map should use "const char *name" instead of "char *name".
You are right, I will provide a patch for it these days.
Cheers,
Matthias
>
> And thank you for your feed back. Well for all suggestions of all of you :)
>
> Am 15.10.2014 um 23:31 schrieb Matthias Brugger:
>>
>>
>> On 14/10/14 10:03, Oleksij Rempel wrote:
>>> In some cases asm9260 looks similar to iMX2x. One of exceptions is
>>> timer controller. So this patch introduces new driver for this special case.
>>>
>>> Signed-off-by: Oleksij Rempel <linux at rempel-privat.de>
>>> ---
>>> drivers/clocksource/Kconfig | 4 +
>>> drivers/clocksource/Makefile | 1 +
>>> drivers/clocksource/asm9260_timer.c | 234 ++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 239 insertions(+)
>>> create mode 100644 drivers/clocksource/asm9260_timer.c
>>>
>>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
>>> index cfd6519..6a03d34 100644
>>> --- a/drivers/clocksource/Kconfig
>>> +++ b/drivers/clocksource/Kconfig
>>> @@ -216,4 +216,8 @@ config CLKSRC_VERSATILE
>>> ARM Versatile, RealView and Versatile Express reference
>>> platforms.
>>>
>>> +config ASM9260_TIMER
>>> + select CLKSRC_MMIO
>>> + bool
>>> +
>>> endmenu
>>> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
>>> index 7fd9fd1..fc93854 100644
>>> --- a/drivers/clocksource/Makefile
>>> +++ b/drivers/clocksource/Makefile
>>> @@ -44,3 +44,4 @@ obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o
>>> obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o
>>> obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o
>>> obj-$(CONFIG_CLKSRC_VERSATILE) += versatile.o
>>> +obj-$(CONFIG_ASM9260_TIMER) += asm9260_timer.o
>>> diff --git a/drivers/clocksource/asm9260_timer.c b/drivers/clocksource/asm9260_timer.c
>>> new file mode 100644
>>> index 0000000..1b16e00
>>> --- /dev/null
>>> +++ b/drivers/clocksource/asm9260_timer.c
>>> @@ -0,0 +1,234 @@
>>> +/*
>>> + * Copyright (C) 2014 Oleksij Rempel <linux at rempel-privat.de>
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License
>>> + * as published by the Free Software Foundation; either version 2
>>> + * of the License, or (at your option) any later version.
>>> + */
>>> +
>>> +#include <linux/kernel.h>
>>> +#include <linux/init.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/sched.h>
>>> +#include <linux/clk.h>
>>> +#include <linux/clocksource.h>
>>> +#include <linux/clockchips.h>
>>> +#include <linux/io.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/of_irq.h>
>>> +#include <linux/bitops.h>
>>> +
>>> +
>>> +/*
>>> + * this device provide 4 offsets for each register:
>>> + * 0x0 - plain read write mode
>>> + * 0x4 - set mode, OR logic.
>>> + * 0x8 - clr mode, XOR logic.
>>> + * 0xc - togle mode.
>>> + */
>>> +#define SET_REG 4
>>> +#define CLR_REG 8
>>> +
>>> +#define HW_IR 0x0000 /* RW. Interrupt */
>>> +#define BM_IR_CR0 BIT(4)
>>> +#define BM_IR_MR3 BIT(3)
>>> +#define BM_IR_MR2 BIT(2)
>>> +#define BM_IR_MR1 BIT(1)
>>> +#define BM_IR_MR0 BIT(0)
>>> +
>>> +#define HW_TCR 0x0010 /* RW. Timer controller */
>>> +/* BM_C*_RST
>>> + * Timer Counter and the Prescale Counter are synchronously reset on the
>>> + * next positive edge of PCLK. The counters remain reset until TCR[1] is
>>> + * returned to zero. */
>>> +#define BM_C3_RST BIT(7)
>>> +#define BM_C2_RST BIT(6)
>>> +#define BM_C1_RST BIT(5)
>>> +#define BM_C0_RST BIT(4)
>>> +/* BM_C*_EN
>>> + * 1 - Timer Counter and Prescale Counter are enabled for counting
>>> + * 0 - counters are disabled */
>>> +#define BM_C3_EN BIT(3)
>>> +#define BM_C2_EN BIT(2)
>>> +#define BM_C1_EN BIT(1)
>>> +#define BM_C0_EN BIT(0)
>>> +
>>> +#define HW_DIR 0x0020 /* RW. Direction? */
>>> +/* 00 - count up
>>> + * 01 - count down
>>> + * 10 - ?? 2^n/2 */
>>> +#define BM_DIR0_SHIFT 0
>>> +#define BM_DIR1_SHIFT 4
>>> +#define BM_DIR2_SHIFT 8
>>> +#define BM_DIR3_SHIFT 12
>>> +
>>> +#define HW_TC0 0x0030 /* RO. Timer counter 0 */
>>> +/* HW_TC*. Timer counter owerflow (0xffff.ffff to 0x0000.0000) do not generate
>>> + * interrupt. This registers can be used to detect overflow */
>>> +#define HW_TC1 0x0040
>>> +#define HW_TC2 0x0050
>>> +#define HW_TC3 0x0060
>>> +
>>> +#define HW_PR 0x0070 /* RW. prescaler */
>>> +#define HW_PC 0x0080 /* RO. Prescaler counter */
>>> +#define HW_MCR 0x0090 /* RW. Match control */
>>> +/* enable interrupt on match */
>>> +#define BM_MCR_INT_EN(n) (1 << (n * 3 + 0))
>>> +/* enable TC reset on match */
>>> +#define BM_MCR_RES_EN(n) (1 << (n * 3 + 1))
>>> +/* enable stop TC on match */
>>> +#define BM_MCR_STOP_EN(n) (1 << (n * 3 + 2))
>>> +
>>> +#define HW_MR0 0x00a0 /* RW. Match reg */
>>> +#define HW_MR1 0x00b0
>>> +#define HW_MR2 0x00C0
>>> +#define HW_MR3 0x00D0
>>> +#define HW_CCR 0x00E0 /* RW. Capture control */
>>> +#define HW_CR0 0x00F0 /* RO. Capture reg */
>>> +#define HW_CR1 0x0100
>>> +#define HW_CR2 0x0110
>>> +#define HW_CR3 0x0120
>>> +#define HW_EMR 0x0130 /* RW. External Match */
>>> +#define HW_PWMTH0 0x0140 /* RW. PWM width */
>>> +#define HW_PWMTH1 0x0150
>>> +#define HW_PWMTH2 0x0160
>>> +#define HW_PWMTH3 0x0170
>>> +#define HW_CTCR 0x0180 /* Counter control */
>>> +#define HW_PWMC 0x0190 /* PWM control */
>>
>> Please delete unused defines.
>>
>>> +
>>> +static void __iomem *base;
>>> +static unsigned long ticks_per_jiffy;
>>
>> More elegant would be to put this in a struct which you pass to the
>> functions.
>>
>>> +
>>> +static int asm9260_timer_set_next_event(unsigned long delta,
>>> + struct clock_event_device *dev)
>>> +{
>>> + /* configure match count for TC0 */
>>> + writel_relaxed(delta, base + HW_MR0);
>>> + /* enable TC0 */
>>> + writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
>>> + return 0;
>>> +}
>>> +
>>> +static void asm9260_timer_set_mode(enum clock_event_mode mode,
>>> + struct clock_event_device *evt)
>>> +{
>>> + /* stop timer0 */
>>> + writel_relaxed(BM_C0_EN, base + HW_TCR + CLR_REG);
>>> +
>>> + switch (mode) {
>>> + case CLOCK_EVT_MODE_PERIODIC:
>>> + /* disable reset and stop on match */
>>> + writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
>>> + base + HW_MCR + CLR_REG);
>>> + /* configure match count for TC0 */
>>> + writel_relaxed(ticks_per_jiffy, base + HW_MR0);
>>> + /* enable TC0 */
>>> + writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
>>> + break;
>>> + case CLOCK_EVT_MODE_ONESHOT:
>>> + /* enable reset and stop on match */
>>> + writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
>>> + base + HW_MCR + SET_REG);
>>> + break;
>>> + default:
>>> + break;
>>> + }
>>> +}
>>> +
>>> +static struct clock_event_device asm9260_clockevent_device = {
>>> + .name = "asm9260-clockevent-dev",
>>> + .rating = 200,
>>> + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
>>> + .set_next_event = asm9260_timer_set_next_event,
>>> + .set_mode = asm9260_timer_set_mode,
>>> +};
>>> +
>>> +static irqreturn_t asm9260_timer_interrupt(int irq, void *dev_id)
>>> +{
>>> + struct clock_event_device *evt = &asm9260_clockevent_device;
>>> +
>>> + evt->event_handler(evt);
>>> +
>>> + writel_relaxed(BM_IR_MR0, base + HW_IR);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> +static struct irqaction asm9260_timer_irq = {
>>> + .name = "asm9260-clockevent-dev",
>>> + .flags = IRQF_TIMER | IRQF_IRQPOLL,
>>> + .handler = asm9260_timer_interrupt,
>>> +};
>>> +
>>> +/*
>>> + * ---------------------------------------------------------------------------
>>> + * Timer initialization
>>> + * ---------------------------------------------------------------------------
>>> + */
>>> +
>>> +static void __init asm9260_clockevent_init(struct clk *clk)
>>> +{
>>> + unsigned long rate = clk_get_rate(clk);
>>> +
>>> + ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
>>> + asm9260_clockevent_device.cpumask = cpumask_of(0);
>>> + clockevents_config_and_register(&asm9260_clockevent_device,
>>> + rate, 0x2c00, 0xfffffffe);
>>> +}
>>> +
>>> +static void __init asm9260_clocksource_init(struct clk *clk)
>>> +{
>>> + unsigned long hz = clk_get_rate(clk);
>>
>> Why not call this in the asm9260_timer_init functions and pass the rate
>> to clockevent_init and clocksource_init?
>>
>>> +
>>> + clocksource_mmio_init(base + HW_TC1,
>>> + "asm9260-clocksource", hz,
>>> + 200, 32, clocksource_mmio_readl_up);
>>> +
>>> + /* Seems like we can't use counter without match register even if
>>> + * actions for MR are disabled. */
>>> + writel_relaxed(0xffffffff, base + HW_MR1);
>>> + /* enable TC1 */
>>> + writel_relaxed(BM_C1_EN, base + HW_TCR + SET_REG);
>>> +}
>>> +
>>> +static void __init asm9260_timer_init(struct device_node *np)
>>> +{
>>> + int irq;
>>> + struct clk *clk;
>>> + struct resource res;
>>> + int ret;
>>> +
>>> + of_address_to_resource(np, 0, &res);
>>> + if (!request_mem_region(res.start, resource_size(&res),
>>> + "asm9260-timer"))
>>> + panic("%s: unable to request mem region", np->name);
>>> +
>>> + base = ioremap_nocache(res.start, resource_size(&res));
>>> + if (!base)
>>> + panic("%s: unable to map resource", np->name);
>>
>> Why don't you use of_io_request_and_map instead of this block?
>>
>>> +
>>> + clk = of_clk_get(np, 0);
>>> +
>>> + ret = clk_prepare_enable(clk);
>>> + if (ret)
>>> + panic("Failed to enable clk!\n");
>>> +
>>> + irq = irq_of_parse_and_map(np, 0);
>>> + setup_irq(irq, &asm9260_timer_irq);
>>
>> Please use request_irq instead.
>>
>>> +
>>> + /* set all timers for count-up */
>>> + writel_relaxed(0, base + HW_DIR);
>>> + /* disable divider */
>>> + writel_relaxed(0, base + HW_PR);
>>> + /* make sure all timers use every rising PCLK edge. */
>>> + writel_relaxed(0, base + HW_CTCR);
>>
>> Please use a define for this.
>>
>>> + /* enable interrupt for TC0 and clean setting for all other lines */
>>> + writel_relaxed(BM_MCR_INT_EN(0) , base + HW_MCR);
>>> +
>>> + asm9260_clocksource_init(clk);
>>> + asm9260_clockevent_init(clk);
>>> +}
>>> +CLOCKSOURCE_OF_DECLARE(asm9260_timer, "alphascale,asm9260-timer",
>>> + asm9260_timer_init);
>>>
>
>
> --
> Regards,
> Oleksij
>
--
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