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

[Peng Fan <van.freenix@gmail.com>]

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@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@nxp.com>
>> Signed-off-by: Ye Li <ye.li@nxp.com>
>> Cc: Stefano Babic <sbabic@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.
>
>Best regards,
>Stefano Babic
>
>-- 
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