[PATCH] watchdog: Add MAX6370 watchdog timer driver

Fri May 6 07:09:37 CEST 2022

On 05.05.22 19:15, Pali Rohár wrote:
> On Thursday 05 May 2022 11:36:09 Pali Rohár wrote:
>> On Tuesday 03 May 2022 07:16:34 Stefan Roese wrote:
>>> On 02.05.22 18:41, Pali Rohár wrote:
>>>> MAX6370 watchdog is available e.g. on Freescale P1/P2 RDB-PC boards.
>>>>
>>>> Signed-off-by: Pali Rohár <pali at kernel.org>
>>>> ---
>>>>    drivers/watchdog/Kconfig       |   7 ++
>>>>    drivers/watchdog/Makefile      |   1 +
>>>>    drivers/watchdog/max6370_wdt.c | 119 +++++++++++++++++++++++++++++++++
>>>>    3 files changed, 127 insertions(+)
>>>>    create mode 100644 drivers/watchdog/max6370_wdt.c
>>>>
>>>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>>>> index f90f0ca02bce..1801698ac512 100644
>>>> --- a/drivers/watchdog/Kconfig
>>>> +++ b/drivers/watchdog/Kconfig
>>>> @@ -167,6 +167,13 @@ config WDT_GPIO
>>>>    	  doc/device-tree-bindings/watchdog/gpio-wdt.txt for
>>>>    	  information on how to describe the watchdog in device tree.
>>>> +config WDT_MAX6370
>>>> +	bool "MAX6370 watchdog timer support"
>>>> +	depends on WDT
>>>> +	select DM_GPIO
>>>> +	help
>>>> +	  Select this to enable max6370 watchdog timer.
>>>> +
>>>>    config WDT_MPC8xx
>>>>    	bool "MPC8xx watchdog timer support"
>>>>    	depends on WDT && MPC8xx
>>>> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
>>>> index a35bd559f51b..f999e4126b4f 100644
>>>> --- a/drivers/watchdog/Makefile
>>>> +++ b/drivers/watchdog/Makefile
>>>> @@ -27,6 +27,7 @@ obj-$(CONFIG_WDT_CORTINA) += cortina_wdt.o
>>>>    obj-$(CONFIG_WDT_ORION) += orion_wdt.o
>>>>    obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o
>>>>    obj-$(CONFIG_WDT_GPIO) += gpio_wdt.o
>>>> +obj-$(CONFIG_WDT_MAX6370) += max6370_wdt.o
>>>>    obj-$(CONFIG_WDT_MPC8xx) += mpc8xx_wdt.o
>>>>    obj-$(CONFIG_WDT_MT7620) += mt7620_wdt.o
>>>>    obj-$(CONFIG_WDT_MT7621) += mt7621_wdt.o
>>>> diff --git a/drivers/watchdog/max6370_wdt.c b/drivers/watchdog/max6370_wdt.c
>>>> new file mode 100644
>>>> index 000000000000..556c6a4b6d6b
>>>> --- /dev/null
>>>> +++ b/drivers/watchdog/max6370_wdt.c
>>>> @@ -0,0 +1,119 @@
>>>> +// SPDX-License-Identifier: GPL-2.0+
>>>> +// (C) 2022 Pali Rohár <pali at kernel.org>
>>>> +
>>>> +#include <common.h>
>>>
>>> AFAIK, it's not recommended any more to include "common.h" in general.
>>
>> Hello! I checked that driver compiles without any errors/warnings also
>> when common.h is removed. So it can be dropped.
> 
> I have tested this driver on P2020 board. Together with P2020 board code
> workaround which I sent in separate patch, watchdog is working correctly
> https://patchwork.ozlabs.org/project/uboot/patch/20220501122314.32626-2-pali@kernel.org/

Good. I'll send a pull request for the MAX6370 watchdog driver later
today. I've removed including "common.h" here.

Thanks,
Stefan

>>> Looks good, other than this:
>>>
>>> Reviewed-by: Stefan Roese <sr at denx.de>
>>>
>>> Thanks,
>>> Stefan
>>>
>>>> +#include <asm/io.h>
>>>> +#include <asm-generic/gpio.h>
>>>> +#include <dm.h>
>>>> +#include <linux/delay.h>
>>>> +#include <wdt.h>
>>>> +
>>>> +#define MAX6370_SET_MASK	0x7
>>>> +#define MAX6370_SET_1MS		0x0
>>>> +#define MAX6370_SET_10MS	0x1
>>>> +#define MAX6370_SET_30MS	0x2
>>>> +#define MAX6370_SET_DISABLE	0x3
>>>> +#define MAX6370_SET_100MS	0x4
>>>> +#define MAX6370_SET_1S		0x5
>>>> +#define MAX6370_SET_10S		0x6
>>>> +#define MAX6370_SET_60S		0x7
>>>> +
>>>> +#define MAX6370_WDI		0x8
>>>> +
>>>> +struct max6370_wdt {
>>>> +	void __iomem *reg;
>>>> +	struct gpio_desc gpio_wdi;
>>>> +};
>>>> +
>>>> +static int max6370_wdt_start(struct udevice *dev, u64 ms, ulong flags)
>>>> +{
>>>> +	struct max6370_wdt *wdt = dev_get_priv(dev);
>>>> +	u8 val;
>>>> +
>>>> +	val = readb(wdt->reg);
>>>> +	val &= ~MAX6370_SET_MASK;
>>>> +
>>>> +	if (ms <= 1)
>>>> +		val |= MAX6370_SET_1MS;
>>>> +	else if (ms <= 10)
>>>> +		val |= MAX6370_SET_10MS;
>>>> +	else if (ms <= 30)
>>>> +		val |= MAX6370_SET_30MS;
>>>> +	else if (ms <= 100)
>>>> +		val |= MAX6370_SET_100MS;
>>>> +	else if (ms <= 1000)
>>>> +		val |= MAX6370_SET_1S;
>>>> +	else if (ms <= 10000)
>>>> +		val |= MAX6370_SET_10S;
>>>> +	else
>>>> +		val |= MAX6370_SET_60S;
>>>> +
>>>> +	writeb(val, wdt->reg);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static int max6370_wdt_stop(struct udevice *dev)
>>>> +{
>>>> +	struct max6370_wdt *wdt = dev_get_priv(dev);
>>>> +	u8 val;
>>>> +
>>>> +	val = readb(wdt->reg);
>>>> +	val &= ~MAX6370_SET_MASK;
>>>> +	val |= MAX6370_SET_DISABLE;
>>>> +	writeb(val, wdt->reg);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static int max6370_wdt_reset(struct udevice *dev)
>>>> +{
>>>> +	struct max6370_wdt *wdt = dev_get_priv(dev);
>>>> +	u8 val;
>>>> +
>>>> +	if (dm_gpio_is_valid(&wdt->gpio_wdi)) {
>>>> +		dm_gpio_set_value(&wdt->gpio_wdi, 1);
>>>> +		udelay(1);
>>>> +		dm_gpio_set_value(&wdt->gpio_wdi, 0);
>>>> +	} else {
>>>> +		val = readb(wdt->reg);
>>>> +		writeb(val | MAX6370_WDI, wdt->reg);
>>>> +		writeb(val & ~MAX6370_WDI, wdt->reg);
>>>> +	}
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static int max6370_wdt_probe(struct udevice *dev)
>>>> +{
>>>> +	struct max6370_wdt *wdt = dev_get_priv(dev);
>>>> +
>>>> +	wdt->reg = dev_read_addr_ptr(dev);
>>>> +	if (!wdt->reg)
>>>> +		return -EINVAL;
>>>> +
>>>> +	/* WDI gpio is optional */
>>>> +	gpio_request_by_name(dev, "gpios", 0, &wdt->gpio_wdi, GPIOD_IS_OUT);
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static const struct wdt_ops max6370_wdt_ops = {
>>>> +	.start = max6370_wdt_start,
>>>> +	.stop = max6370_wdt_stop,
>>>> +	.reset = max6370_wdt_reset,
>>>> +};
>>>> +
>>>> +static const struct udevice_id max6370_wdt_ids[] = {
>>>> +	{ .compatible = "maxim,max6370" },
>>>> +	{}
>>>> +};
>>>> +
>>>> +U_BOOT_DRIVER(max6370_wdt) = {
>>>> +	.name = "max6370_wdt",
>>>> +	.id = UCLASS_WDT,
>>>> +	.of_match = max6370_wdt_ids,
>>>> +	.probe = max6370_wdt_probe,
>>>> +	.priv_auto = sizeof(struct max6370_wdt),
>>>> +	.ops = &max6370_wdt_ops,
>>>> +};
>>>
>>> Viele Grüße,
>>> Stefan Roese
>>>
>>> -- 
>>> DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
>>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>>> Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr at denx.de

Viele Grüße,
Stefan Roese

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-51 Fax: (+49)-8142-66989-80 Email: sr at denx.de