On Tue, Oct 18, 2022 at 08:38:19AM +0200, Thomas Kastner wrote: > This patch adds the 'advantech_ec_wdt' kernel module which provides > WDT support for Advantech platforms with ITE based Embedded Controller. > > Signed-off-by: Thomas Kastner <thomas.kastner@xxxxxxxxxxxxx> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> > --- > > v3: > - removed author email and disclaimer in file header > - changed EC_ADDR_DATA/CMD to be based on EC_BASE_ADDR instead of fixed > - fixed checkpatch.pl reported issues > long line preferred over "quoted strings split across lines" due to grep > > v2: > - added accessor function for EC IO access to remove unnecessary waits > - moved EC probe to adv_ec_wdt_init() > - implemented cosmetic changes found in the code review > - removed debug output and unnecessary error messages > > v1: > - initial version > > drivers/watchdog/Kconfig | 7 + > drivers/watchdog/Makefile | 1 + > drivers/watchdog/advantech_ec_wdt.c | 205 ++++++++++++++++++++++++++++ > 3 files changed, 213 insertions(+) > create mode 100644 drivers/watchdog/advantech_ec_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 688922fc4edb..a990016f791c 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -1055,6 +1055,13 @@ config ADVANTECH_WDT > feature. More information can be found at > <https://www.advantech.com.tw/products/> > > +config ADVANTECH_EC_WDT > + tristate "Advantech Embedded Controller Watchdog Timer" > + depends on X86 > + help > + This driver supports Advantech products with ITE based Embedded Controller. > + It does not support Advantech products with other ECs or without EC. > + > config ALIM1535_WDT > tristate "ALi M1535 PMU Watchdog Timer" > depends on X86 && PCI > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index cdeb119e6e61..2768dc2348af 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -102,6 +102,7 @@ obj-$(CONFIG_SUNPLUS_WATCHDOG) += sunplus_wdt.o > # X86 (i386 + ia64 + x86_64) Architecture > obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o > obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o > +obj-$(CONFIG_ADVANTECH_EC_WDT) += advantech_ec_wdt.o > obj-$(CONFIG_ALIM1535_WDT) += alim1535_wdt.o > obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o > obj-$(CONFIG_EBC_C384_WDT) += ebc-c384_wdt.o > diff --git a/drivers/watchdog/advantech_ec_wdt.c b/drivers/watchdog/advantech_ec_wdt.c > new file mode 100644 > index 000000000000..d6dfc1347ca5 > --- /dev/null > +++ b/drivers/watchdog/advantech_ec_wdt.c > @@ -0,0 +1,205 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Advantech Embedded Controller Watchdog Driver > + * > + * This driver supports Advantech products with ITE based Embedded Controller. > + * It does not support Advantech products with other ECs or without EC. > + * > + * Copyright (C) 2022 Advantech Europe B.V. > + */ > + > +#include <linux/delay.h> > +#include <linux/io.h> > +#include <linux/isa.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/watchdog.h> > + > +#define DRIVER_NAME "advantech_ec_wdt" > + > +/* EC IO region */ > +#define EC_BASE_ADDR 0x299 > +#define EC_ADDR_EXTENT 2 > + > +/* EC minimum IO access delay in ms */ > +#define EC_MIN_DELAY 10 > + > +/* EC interface definitions */ > +#define EC_ADDR_CMD (EC_BASE_ADDR + 1) > +#define EC_ADDR_DATA EC_BASE_ADDR > +#define EC_CMD_EC_PROBE 0x30 > +#define EC_CMD_COMM 0x89 > +#define EC_CMD_WDT_START 0x28 > +#define EC_CMD_WDT_STOP 0x29 > +#define EC_CMD_WDT_RESET 0x2A > +#define EC_DAT_EN_DLY_H 0x58 > +#define EC_DAT_EN_DLY_L 0x59 > +#define EC_DAT_RST_DLY_H 0x5E > +#define EC_DAT_RST_DLY_L 0x5F > +#define EC_MAGIC 0x95 > + > +/* module parameters */ > +#define MIN_TIME 1 > +#define MAX_TIME 6000 /* 100 minutes */ > +#define DEFAULT_TIME 60 > + > +static unsigned int timeout; > +static ktime_t ec_timestamp; > + > +module_param(timeout, uint, 0); > +MODULE_PARM_DESC(timeout, > + "Default Watchdog timer setting (" __MODULE_STRING(DEFAULT_TIME) "s). The range is from " __MODULE_STRING(MIN_TIME) " to " __MODULE_STRING(MAX_TIME) "."); > + > +static void adv_ec_wdt_timing_gate(void) > +{ > + ktime_t time_cur, time_delta; > + > + /* ensure minimum delay between IO accesses*/ > + time_cur = ktime_get(); > + time_delta = ktime_to_ms(ktime_sub(time_cur, ec_timestamp)); > + if (time_delta < EC_MIN_DELAY) { > + time_delta = EC_MIN_DELAY - time_delta; > + usleep_range(time_delta * 1000, (time_delta + 1) * 1000); > + } > + ec_timestamp = ktime_get(); > +} > + > +static void adv_ec_wdt_outb(unsigned char value, unsigned short port) > +{ > + adv_ec_wdt_timing_gate(); > + outb(value, port); > +} > + > +static unsigned char adv_ec_wdt_inb(unsigned short port) > +{ > + adv_ec_wdt_timing_gate(); > + return inb(port); > +} > + > +static int adv_ec_wdt_ping(struct watchdog_device *wdd) > +{ > + adv_ec_wdt_outb(EC_CMD_WDT_RESET, EC_ADDR_CMD); > + return 0; > +} > + > +static int adv_ec_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) > +{ > + unsigned int val; > + > + /* scale time to EC 100 ms base */ > + val = t * 10; > + > + /* reset enable delay, just in case it was set by BIOS etc. */ > + adv_ec_wdt_outb(EC_CMD_COMM, EC_ADDR_CMD); > + adv_ec_wdt_outb(EC_DAT_EN_DLY_H, EC_ADDR_DATA); > + adv_ec_wdt_outb(0, EC_ADDR_DATA); > + > + adv_ec_wdt_outb(EC_CMD_COMM, EC_ADDR_CMD); > + adv_ec_wdt_outb(EC_DAT_EN_DLY_L, EC_ADDR_DATA); > + adv_ec_wdt_outb(0, EC_ADDR_DATA); > + > + /* set reset delay */ > + adv_ec_wdt_outb(EC_CMD_COMM, EC_ADDR_CMD); > + adv_ec_wdt_outb(EC_DAT_RST_DLY_H, EC_ADDR_DATA); > + adv_ec_wdt_outb(val >> 8, EC_ADDR_DATA); > + > + adv_ec_wdt_outb(EC_CMD_COMM, EC_ADDR_CMD); > + adv_ec_wdt_outb(EC_DAT_RST_DLY_L, EC_ADDR_DATA); > + adv_ec_wdt_outb(val & 0xFF, EC_ADDR_DATA); > + > + wdd->timeout = t; > + return 0; > +} > + > +static int adv_ec_wdt_start(struct watchdog_device *wdd) > +{ > + adv_ec_wdt_set_timeout(wdd, wdd->timeout); > + adv_ec_wdt_outb(EC_CMD_WDT_START, EC_ADDR_CMD); > + > + return 0; > +} > + > +static int adv_ec_wdt_stop(struct watchdog_device *wdd) > +{ > + adv_ec_wdt_outb(EC_CMD_WDT_STOP, EC_ADDR_CMD); > + > + return 0; > +} > + > +static const struct watchdog_info adv_ec_wdt_info = { > + .identity = DRIVER_NAME, > + .options = WDIOF_SETTIMEOUT | > + WDIOF_MAGICCLOSE | > + WDIOF_KEEPALIVEPING, > +}; > + > +static const struct watchdog_ops adv_ec_wdt_ops = { > + .owner = THIS_MODULE, > + .start = adv_ec_wdt_start, > + .stop = adv_ec_wdt_stop, > + .ping = adv_ec_wdt_ping, > + .set_timeout = adv_ec_wdt_set_timeout, > +}; > + > +static struct watchdog_device adv_ec_wdt_dev = { > + .info = &adv_ec_wdt_info, > + .ops = &adv_ec_wdt_ops, > + .min_timeout = MIN_TIME, > + .max_timeout = MAX_TIME, > + .timeout = DEFAULT_TIME, > +}; > + > +static int adv_ec_wdt_probe(struct device *dev, unsigned int id) > +{ > + if (!devm_request_region(dev, EC_BASE_ADDR, EC_ADDR_EXTENT, dev_name(dev))) { > + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", > + EC_BASE_ADDR, EC_BASE_ADDR + EC_ADDR_EXTENT); > + return -EBUSY; > + } > + > + watchdog_init_timeout(&adv_ec_wdt_dev, timeout, dev); > + watchdog_stop_on_reboot(&adv_ec_wdt_dev); > + watchdog_stop_on_unregister(&adv_ec_wdt_dev); > + > + return devm_watchdog_register_device(dev, &adv_ec_wdt_dev); > +} > + > +static struct isa_driver adv_ec_wdt_driver = { > + .probe = adv_ec_wdt_probe, > + .driver = { > + .name = DRIVER_NAME, > + }, > +}; > + > +static int __init adv_ec_wdt_init(void) > +{ > + unsigned int val; > + > + /* quick probe for EC */ > + if (!request_region(EC_BASE_ADDR, EC_ADDR_EXTENT, DRIVER_NAME)) > + return -EBUSY; > + > + adv_ec_wdt_outb(EC_CMD_EC_PROBE, EC_ADDR_CMD); > + val = adv_ec_wdt_inb(EC_ADDR_DATA); > + release_region(EC_BASE_ADDR, EC_ADDR_EXTENT); > + > + if (val != EC_MAGIC) > + return -ENODEV; > + > + return isa_register_driver(&adv_ec_wdt_driver, 1); > +} > + > +static void __exit adv_ec_wdt_exit(void) > +{ > + isa_unregister_driver(&adv_ec_wdt_driver); > +} > + > +module_init(adv_ec_wdt_init); > +module_exit(adv_ec_wdt_exit); > + > +MODULE_AUTHOR("Thomas Kastner <thomas.kastne@xxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Advantech Embedded Controller Watchdog Device Driver"); > +MODULE_LICENSE("GPL"); > +MODULE_VERSION("20221018"); > +MODULE_ALIAS("isa:" DRIVER_NAME); > -- > 2.34.1 >
