[U-Boot] [PATCH V2 11/20] wdog: Add the watchdog driver for MX7ULP.

[Stefano Babic]

On 22/02/2017 07:59, Peng Fan wrote:
> On Sun, Feb 12, 2017 at 10:25:02AM +0100, Stefano Babic wrote:
>>
>>
>> On 27/12/2016 11:04, Peng Fan wrote:
>>> From: Ye Li <ye.li at nxp.com>
>>>
>>> This driver implements the HW WATCHDOG functions. Which needs
>>> to set CONFIG_HW_WATCHDOG to use them. This is disabled by default for
>>> mx7ulp.
>>>
>>> Use watchdog for reset cpu. Implement this in the driver.
>>> Need to define CONFIG_ULP_WATCHDOG to build it.
>>>
>>> Signed-off-by: Peng Fan <peng.fan at nxp.com>
>>> Signed-off-by: Ye Li <ye.li at nxp.com>
>>> Cc: Stefano Babic <sbabic at denx.de>
>>> ---
>>>
>>> V2:
>>>  Add License
>>>
>>>  drivers/watchdog/Kconfig    |  8 ++++
>>>  drivers/watchdog/Makefile   |  1 +
>>>  drivers/watchdog/ulp_wdog.c | 98 +++++++++++++++++++++++++++++++++++++++++++++
>>>  3 files changed, 107 insertions(+)
>>>  create mode 100644 drivers/watchdog/ulp_wdog.c
>>>
>>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>>> index e69de29..dbdaafc 100644
>>> --- a/drivers/watchdog/Kconfig
>>> +++ b/drivers/watchdog/Kconfig
>>> @@ -0,0 +1,8 @@
>>> +menu "WATCHDOG support"
>>> +
>>> +config ULP_WATCHDOG
>>> +	bool "i.MX7ULP watchdog"
>>> +	help
>>> +	  Say Y here to enable i.MX7ULP watchdog driver.
>>> +
>>> +endmenu
>>> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
>>> index a007ae8..dea1836 100644
>>> --- a/drivers/watchdog/Makefile
>>> +++ b/drivers/watchdog/Makefile
>>> @@ -15,3 +15,4 @@ obj-$(CONFIG_XILINX_TB_WATCHDOG) += xilinx_tb_wdt.o
>>>  obj-$(CONFIG_BFIN_WATCHDOG)  += bfin_wdt.o
>>>  obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
>>>  obj-$(CONFIG_DESIGNWARE_WATCHDOG) += designware_wdt.o
>>> +obj-$(CONFIG_ULP_WATCHDOG) += ulp_wdog.o
>>> diff --git a/drivers/watchdog/ulp_wdog.c b/drivers/watchdog/ulp_wdog.c
>>> new file mode 100644
>>> index 0000000..72ec694
>>> --- /dev/null
>>> +++ b/drivers/watchdog/ulp_wdog.c
>>> @@ -0,0 +1,98 @@
>>> +/*
>>> + * Copyright (C) 2016 Freescale Semiconductor, Inc.
>>> + *
>>> + * SPDX-License-Identifier:	GPL-2.0+
>>> + */
>>> +
>>> +#include <common.h>
>>> +#include <asm/io.h>
>>> +#include <asm/arch/imx-regs.h>
>>> +
>>> +/*
>>> + * MX7ULP WDOG Register Map
>>> + */
>>> +struct wdog_regs {
>>> +	u8 cs1;
>>> +	u8 cs2;
>>> +	u16 reserve0;
>>> +	u32 cnt;
>>> +	u32 toval;
>>> +	u32 win;
>>> +};
>>> +
>>> +#ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
>>> +#define CONFIG_WATCHDOG_TIMEOUT_MSECS 0x1500
>>> +#endif
>>> +
>>> +#define REFRESH_WORD0 0xA602 /* 1st refresh word */
>>> +#define REFRESH_WORD1 0xB480 /* 2nd refresh word */
>>> +
>>> +#define UNLOCK_WORD0 0xC520 /* 1st unlock word */
>>> +#define UNLOCK_WORD1 0xD928 /* 2nd unlock word */
>>> +
>>> +#define WDGCS1_WDGE                      (1<<7)
>>> +#define WDGCS1_WDGUPDATE                 (1<<5)
>>> +
>>> +#define WDGCS2_FLG                       (1<<6)
>>> +
>>> +#define WDG_BUS_CLK                      (0x0)
>>> +#define WDG_LPO_CLK                      (0x1)
>>> +#define WDG_32KHZ_CLK                    (0x2)
>>> +#define WDG_EXT_CLK                      (0x3)
>>> +
>>> +DECLARE_GLOBAL_DATA_PTR;
>>> +
>>> +void hw_watchdog_set_timeout(u16 val)
>>> +{
>>> +	/* setting timeout value */
>>> +	struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
>>> +
>>> +	writel(val, &wdog->toval);
>>> +}
>>> +
>>> +void hw_watchdog_reset(void)
>>> +{
>>> +	struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
>>> +
>>> +	writel(REFRESH_WORD0, &wdog->cnt);
>>> +	writel(REFRESH_WORD1, &wdog->cnt);
>>> +}
>>> +
>>> +void hw_watchdog_init(void)
>>> +{
>>> +	u8 val;
>>> +	struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
>>> +
>>> +	writel(UNLOCK_WORD0, &wdog->cnt);
>>> +	writel(UNLOCK_WORD1, &wdog->cnt);
>>> +
>>> +	val = readb(&wdog->cs2);
>>> +	val |= WDGCS2_FLG;
>>> +	writeb(val, &wdog->cs2);
>>> +
>>> +	hw_watchdog_set_timeout(CONFIG_WATCHDOG_TIMEOUT_MSECS);
>>> +	writel(0, &wdog->win);
>>> +
>>> +	writeb(WDG_LPO_CLK, &wdog->cs2);/* setting 1-kHz clock source */
>>> +	writeb((WDGCS1_WDGE | WDGCS1_WDGUPDATE), &wdog->cs1);/* enable counter running */
>>> +
>>> +	hw_watchdog_reset();
>>> +}
>>> +
>>> +void reset_cpu(ulong addr)
>>> +{
>>> +	struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE_ADDR;
>>> +
>>> +	writel(UNLOCK_WORD0, &wdog->cnt);
>>> +	writel(UNLOCK_WORD1, &wdog->cnt);
>>> +
>>> +	hw_watchdog_set_timeout(5); /* 5ms timeout */
>>> +	writel(0, &wdog->win);
>>> +
>>> +	writeb(WDG_LPO_CLK, &wdog->cs2);/* setting 1-kHz clock source */
>>> +	writeb(WDGCS1_WDGE, &wdog->cs1);/* enable counter running */
>>> +
>>> +	hw_watchdog_reset();
>>> +
>>> +	while (1);
>>> +}
>>>
>>
>> This goes into drivers/watchdog, and it slightly differs from the
>> implementation in imx-watchdog.c. Code is quite simple, too, I think it
>> could be merged into the same file.
> 
> I prefer to keep it in different files, the watchdog ip on i.MX7ULP is a different one.

Ok, fine, I do not insist. Then let this into a separate file

Best regards,
Stefano Babic

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