[U-Boot] [PATCH 09/11] imx: system counter driver for imx7d and mx6ul

[Nikolay Dimitrov]

Hi Adrian,

On 07/21/2015 01:11 AM, Alonso Adrian wrote:
> Hi Nikolay,
>
>> -----Original Message-----
>> From: Nikolay Dimitrov [mailto:picmaster at mail.bg]
>> Sent: Monday, July 20, 2015 3:43 PM
>> To: Alonso Lazcano Adrian-B38018
>> Cc: u-boot at lists.denx.de; sbabic at denx.de; Estevam Fabio-R49496;
>> otavio at ossystems.com.br
>> Subject: Re: [U-Boot] [PATCH 09/11] imx: system counter driver for imx7d and
>> mx6ul
>>
>> Hi Adrian,
>>
>> On 07/16/2015 01:49 AM, Adrian Alonso wrote:
>>> * The system counter driver for imx7d abd mx6ul, move
>>>     this timer driver to imx-common and rename it as syscounter.c
>>>
>>>     For mx6ul and mx7, configurations are used for choose the GPT timer
>>>     or system counter timer (default).
>>>
>>>     GPT timer:              CONFIG_GPT_TIMER
>>>     System counter timer:   CONFIG_SYSCOUNTER_TIMER
>>>
>>>     For mx6dqp GPT timer is the default setting.
>>>
>>> Signed-off-by: Adrian Alonso <aalonso at freescale.com>
>>> Signed-off-by: Ye.Li <B37916 at freescale.com>
>>> ---
>>>    arch/arm/imx-common/syscounter.c             | 126
>> +++++++++++++++++++++++++++
>>>    arch/arm/include/asm/imx-common/syscounter.h |  29 ++++++
>>>    include/configs/mx6_common.h                 |   1 +
>>>    3 files changed, 156 insertions(+)
>>>    create mode 100644 arch/arm/imx-common/syscounter.c
>>>    create mode 100644 arch/arm/include/asm/imx-common/syscounter.h
>>>
>>> diff --git a/arch/arm/imx-common/syscounter.c
>>> b/arch/arm/imx-common/syscounter.c
>>> new file mode 100644
>>> index 0000000..f5e5cdc
>>> --- /dev/null
>>> +++ b/arch/arm/imx-common/syscounter.c
>>> @@ -0,0 +1,126 @@
>>> +/*
>>> + * Copyright (C) 2014-2015 Freescale Semiconductor, Inc.
>>> + *
>>> + * SPDX-License-Identifier:	GPL-2.0+
>>> + *
>>> + * The file use ls102xa/timer.c as a reference.
>>> + */
>>> +
>>> +#include <common.h>
>>> +#include <asm/io.h>
>>> +#include <div64.h>
>>> +#include <asm/arch/imx-regs.h>
>>> +#include <asm/arch/sys_proto.h>
>>> +#include <asm/imx-common/syscounter.h>
>>> +
>>> +DECLARE_GLOBAL_DATA_PTR;
>>> +
>>> +/*
>>> + * This function is intended for SHORT delays only.
>>> + * It will overflow at around 10 seconds @ 400MHz,
>>> + * or 20 seconds @ 200MHz.
>>> + */
>>> +unsigned long usec2ticks(unsigned long usec) {
>>> +	ulong ticks;
>>> +
>>> +	if (usec < 1000)
>>> +		ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
>>> +	else
>>> +		ticks = ((usec / 10) * (get_tbclk() / 100000));
>>> +
>>> +	return ticks;
>>> +}
>>> +
>>> +static inline unsigned long long tick_to_time(unsigned long long
>>> +tick) {
>>> +	unsigned long freq;
>>> +
>>> +	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
>>> +
>>> +	tick *= CONFIG_SYS_HZ;
>>> +	do_div(tick, freq);
>>> +
>>> +	return tick;
>>> +}
>>> +
>>> +static inline unsigned long long us_to_tick(unsigned long long usec)
>>> +{
>>> +	unsigned long freq;
>>> +
>>> +	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
>>> +
>>> +	usec = usec * freq  + 999999;
>>> +	do_div(usec, 1000000);
>>> +
>>> +	return usec;
>>> +}
>>
>> Is it possible to use the same naming convention for usec2ticks(),
>> tick_to_time() and us_to_tick() (e.g. choose either "2" or "_to_")?
>> Thanks.
>
>   [Adrian] usec2ticks follows the definition of prototype function in header file "include/common.h"
> the comment in the header /* arch/$(ARCH)/lib/time.c */ implies that each platform should provide
> that function; For iMX SoC's case usec2ticks is only used in drivers/crypto/fsl/jr.c and drivers/i2c/fsl_i2c.c
> IMHO we should keep the same naming convention defined in the "include/common.h" file.

I see. Thanks for explaining!

>
>>
>>> +
>>> +int timer_init(void)
>>> +{
>>> +	struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
>>> +	unsigned long val, freq;
>>> +
>>> +	freq = CONFIG_SC_TIMER_CLK;
>>> +	asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
>>> +
>>> +	writel(freq, &sctr->cntfid0);
>>> +
>>> +	/* Enable system counter */
>>> +	val = readl(&sctr->cntcr);
>>> +	val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1);
>>> +	val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG;
>>> +	writel(val, &sctr->cntcr);
>>> +
>>> +	gd->arch.tbl = 0;
>>> +	gd->arch.tbu = 0;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +unsigned long long get_ticks(void)
>>> +{
>>> +	unsigned long long now;
>>> +
>>> +	asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
>>> +
>>> +	gd->arch.tbl = (unsigned long)(now & 0xffffffff);
>>> +	gd->arch.tbu = (unsigned long)(now >> 32);
>>> +
>>> +	return now;
>>> +}
>>> +
>>> +ulong get_timer_masked(void)
>>> +{
>>> +	return tick_to_time(get_ticks());
>>> +}
>>> +
>>> +ulong get_timer(ulong base)
>>> +{
>>> +	return get_timer_masked() - base;
>>> +}
>>> +
>>> +void __udelay(unsigned long usec)
>>> +{
>>> +	unsigned long long tmp;
>>> +	ulong tmo;
>>> +
>>> +	tmo = us_to_tick(usec);
>>> +	tmp = get_ticks() + tmo;	/* get current timestamp */
>>> +
>>> +	while (get_ticks() < tmp)	/* loop till event */
>>> +		 /*NOP*/;
>>> +}
>>> +
>>> +/*
>>> + * This function is derived from PowerPC code (timebase clock frequency).
>>> + * On ARM it returns the number of timer ticks per second.
>>> + */
>>> +ulong get_tbclk(void)
>>> +{
>>> +	unsigned long freq;
>>> +
>>> +	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
>>> +
>>> +	return freq;
>>> +}
>>> diff --git a/arch/arm/include/asm/imx-common/syscounter.h
>>> b/arch/arm/include/asm/imx-common/syscounter.h
>>> new file mode 100644
>>> index 0000000..ddb412e
>>> --- /dev/null
>>> +++ b/arch/arm/include/asm/imx-common/syscounter.h
>>> @@ -0,0 +1,29 @@
>>> +/*
>>> + * Copyright (C) 2014-2015 Freescale Semiconductor, Inc.
>>> + *
>>> + * SPDX-License-Identifier:	GPL-2.0+
>>> + */
>>> +
>>> +#ifndef _ASM_ARCH_SYSTEM_COUNTER_H
>>> +#define _ASM_ARCH_SYSTEM_COUNTER_H
>>> +
>>> +/* System Counter */
>>> +struct sctr_regs {
>>> +	u32 cntcr;
>>> +	u32 cntsr;
>>> +	u32 cntcv1;
>>> +	u32 cntcv2;
>>> +	u32 resv1[4];
>>> +	u32 cntfid0;
>>> +	u32 cntfid1;
>>> +	u32 cntfid2;
>>> +	u32 resv2[1001];
>>> +	u32 counterid[1];
>>> +};
>>> +
>>> +#define SC_CNTCR_ENABLE		(1 << 0)
>>> +#define SC_CNTCR_HDBG		(1 << 1)
>>> +#define SC_CNTCR_FREQ0		(1 << 8)
>>> +#define SC_CNTCR_FREQ1		(1 << 9)
>>> +
>>> +#endif
>>> diff --git a/include/configs/mx6_common.h
>>> b/include/configs/mx6_common.h index 86d7b16..690038d 100644
>>> --- a/include/configs/mx6_common.h
>>> +++ b/include/configs/mx6_common.h
>>> @@ -30,6 +30,7 @@
>>>
>>>    #define CONFIG_MP
>>>    #define CONFIG_MXC_GPT_HCLK
>>> +#define CONFIG_GPT_TIMER
>>>
>>>    #define CONFIG_SYS_NO_FLASH
>>>
>>>
>>
>> Regards,
>> Nikolay
>
>
>

Regards,
Nikolay