Unverified Commit ab89fb5f authored by Marek Behún's avatar Marek Behún Committed by Arnd Bergmann
Browse files

platform: cznic: turris-omnia-mcu: Add support for MCU watchdog 



Add support for the watchdog mechanism provided by the MCU.

Signed-off-by: default avatarMarek Behún <kabel@kernel.org>
Reviewed-by: default avatarAndy Shevchenko <andy@kernel.org>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Acked-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20240701113010.16447-6-kabel@kernel.org


Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 90e700fd

drivers/platform/cznic/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ config TURRIS_OMNIA_MCU 
	select GPIOLIB

	select GPIOLIB_IRQCHIP

	select RTC_CLASS

	select WATCHDOG_CORE

	help

	  Say Y here to add support for the features implemented by the

	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.
@@ -26,6 +27,7 @@ config TURRIS_OMNIA_MCU 
	  - board poweroff into true low power mode (with voltage regulators

	    disabled) and the ability to configure wake up from this mode (via

	    rtcwake)

	  - MCU watchdog

	  - GPIO pins

	    - to get front button press events (the front button can be

	      configured either to generate press events to the CPU or to change

drivers/platform/cznic/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,3 +4,4 @@ obj-$(CONFIG_TURRIS_OMNIA_MCU) += turris-omnia-mcu.o 
turris-omnia-mcu-y		:= turris-omnia-mcu-base.o

turris-omnia-mcu-y		+= turris-omnia-mcu-gpio.o

turris-omnia-mcu-y		+= turris-omnia-mcu-sys-off-wakeup.o

turris-omnia-mcu-y		+= turris-omnia-mcu-watchdog.o

drivers/platform/cznic/turris-omnia-mcu-base.c

+4 −0
Original line number Diff line number Diff line
@@ -377,6 +377,10 @@ static int omnia_mcu_probe(struct i2c_client *client) 
	if (err)

		return err;



	err = omnia_mcu_register_watchdog(mcu);

	if (err)

		return err;



	return omnia_mcu_register_gpiochip(mcu);

}

drivers/platform/cznic/turris-omnia-mcu-watchdog.c

0 → 100644
+130 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * CZ.NIC's Turris Omnia MCU watchdog driver

 *

 * 2024 by Marek Behún <kabel@kernel.org>

 */



#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/i2c.h>

#include <linux/moduleparam.h>

#include <linux/types.h>

#include <linux/units.h>

#include <linux/watchdog.h>



#include <linux/turris-omnia-mcu-interface.h>

#include "turris-omnia-mcu.h"



#define WATCHDOG_TIMEOUT		120



static unsigned int timeout;

module_param(timeout, int, 0);

MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");



static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="

			   __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");



static int omnia_wdt_start(struct watchdog_device *wdt)

{

	struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);



	return omnia_cmd_write_u8(mcu->client, OMNIA_CMD_SET_WATCHDOG_STATE, 1);

}



static int omnia_wdt_stop(struct watchdog_device *wdt)

{

	struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);



	return omnia_cmd_write_u8(mcu->client, OMNIA_CMD_SET_WATCHDOG_STATE, 0);

}



static int omnia_wdt_ping(struct watchdog_device *wdt)

{

	struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);



	return omnia_cmd_write_u8(mcu->client, OMNIA_CMD_SET_WATCHDOG_STATE, 1);

}



static int omnia_wdt_set_timeout(struct watchdog_device *wdt,

				 unsigned int timeout)

{

	struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);



	return omnia_cmd_write_u16(mcu->client, OMNIA_CMD_SET_WDT_TIMEOUT,

				   timeout * DECI);

}



static unsigned int omnia_wdt_get_timeleft(struct watchdog_device *wdt)

{

	struct omnia_mcu *mcu = watchdog_get_drvdata(wdt);

	u16 timeleft;

	int err;



	err = omnia_cmd_read_u16(mcu->client, OMNIA_CMD_GET_WDT_TIMELEFT,

				 &timeleft);

	if (err) {

		dev_err(&mcu->client->dev, "Cannot get watchdog timeleft: %d\n",

			err);

		return 0;

	}



	return timeleft / DECI;

}



static const struct watchdog_info omnia_wdt_info = {

	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,

	.identity = "Turris Omnia MCU Watchdog",

};



static const struct watchdog_ops omnia_wdt_ops = {

	.owner		= THIS_MODULE,

	.start		= omnia_wdt_start,

	.stop		= omnia_wdt_stop,

	.ping		= omnia_wdt_ping,

	.set_timeout	= omnia_wdt_set_timeout,

	.get_timeleft	= omnia_wdt_get_timeleft,

};



int omnia_mcu_register_watchdog(struct omnia_mcu *mcu)

{

	struct device *dev = &mcu->client->dev;

	u8 state;

	int err;



	if (!(mcu->features & OMNIA_FEAT_WDT_PING))

		return 0;



	mcu->wdt.info = &omnia_wdt_info;

	mcu->wdt.ops = &omnia_wdt_ops;

	mcu->wdt.parent = dev;

	mcu->wdt.min_timeout = 1;

	mcu->wdt.max_timeout = 65535 / DECI;



	mcu->wdt.timeout = WATCHDOG_TIMEOUT;

	watchdog_init_timeout(&mcu->wdt, timeout, dev);



	watchdog_set_drvdata(&mcu->wdt, mcu);



	omnia_wdt_set_timeout(&mcu->wdt, mcu->wdt.timeout);



	err = omnia_cmd_read_u8(mcu->client, OMNIA_CMD_GET_WATCHDOG_STATE,

				&state);

	if (err)

		return dev_err_probe(dev, err,

				     "Cannot get MCU watchdog state\n");



	if (state)

		set_bit(WDOG_HW_RUNNING, &mcu->wdt.status);



	watchdog_set_nowayout(&mcu->wdt, nowayout);

	watchdog_stop_on_reboot(&mcu->wdt);

	err = devm_watchdog_register_device(dev, &mcu->wdt);

	if (err)

		return dev_err_probe(dev, err,

				     "Cannot register MCU watchdog\n");



	return 0;

}

drivers/platform/cznic/turris-omnia-mcu.h

+24 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/if_ether.h>

#include <linux/mutex.h>

#include <linux/types.h>

#include <linux/watchdog.h>

#include <linux/workqueue.h>

#include <asm/byteorder.h>

#include <asm/unaligned.h>
@@ -43,6 +44,9 @@ struct omnia_mcu { 
	struct rtc_device *rtcdev;

	u32 rtc_alarm;

	bool front_button_poweron;



	/* MCU watchdog */

	struct watchdog_device wdt;

};



int omnia_cmd_write_read(const struct i2c_client *client,
@@ -55,6 +59,25 @@ static inline int omnia_cmd_write(const struct i2c_client *client, void *cmd, 
	return omnia_cmd_write_read(client, cmd, len, NULL, 0);

}



static inline int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd,

				     u8 val)

{

	u8 buf[2] = { cmd, val };



	return omnia_cmd_write(client, buf, sizeof(buf));

}



static inline int omnia_cmd_write_u16(const struct i2c_client *client, u8 cmd,

				      u16 val)

{

	u8 buf[3];



	buf[0] = cmd;

	put_unaligned_le16(val, &buf[1]);



	return omnia_cmd_write(client, buf, sizeof(buf));

}



static inline int omnia_cmd_write_u32(const struct i2c_client *client, u8 cmd,

				      u32 val)

{
@@ -158,5 +181,6 @@ extern const struct attribute_group omnia_mcu_poweroff_group; 


int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu);

int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu);

int omnia_mcu_register_watchdog(struct omnia_mcu *mcu);



#endif /* __TURRIS_OMNIA_MCU_H */