This driver provides access to RAVE SP watchdog functionality. Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-watchdog@xxxxxxxxxxxxxxx Cc: cphealy@xxxxxxxxx Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Cc: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx> Cc: Lee Jones <lee.jones@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Pavel Machek <pavel@xxxxxx> Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Cc: Rob Herring <robh@xxxxxxxxxx> Cc: Johan Hovold <johan@xxxxxxxxxx> Signed-off-by: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx> --- Guenter: In our previous discussion you noted that relying on the state of WDOG_HW_RUNNING was not correct (that should be fixed now), please let me know if using watchdog_hw_running() the way I do in rave_sp_wdt_set_timeout() is incorrect as well. Thanks, Andrey Smirnov drivers/watchdog/Kconfig | 7 + drivers/watchdog/Makefile | 1 + drivers/watchdog/rave-sp-wdt.c | 343 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 351 insertions(+) create mode 100644 drivers/watchdog/rave-sp-wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index c722cbfdc7e6..533a72248cd1 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -223,6 +223,13 @@ config ZIIRAVE_WATCHDOG To compile this driver as a module, choose M here: the module will be called ziirave_wdt. +config RAVE_SP_WATCHDOG + tristate "RAVE SP Watchdog timer" + depends on RAVE_SP_CORE + select WATCHDOG_CORE + help + Support for the watchdog on RAVE SP device. + # ALPHA Architecture # ARM Architecture diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 56adf9fa67d0..5c9556c09f6e 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -223,3 +223,4 @@ obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o +obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o diff --git a/drivers/watchdog/rave-sp-wdt.c b/drivers/watchdog/rave-sp-wdt.c new file mode 100644 index 000000000000..c8e263f0cad1 --- /dev/null +++ b/drivers/watchdog/rave-sp-wdt.c @@ -0,0 +1,343 @@ +/* + * rave-sp-wdt.c - Watchdog driver present in RAVE SP + * + * Copyright (C) 2017 Zodiac Inflight Innovation + * + * Driver for parent device can be found in drivers/mfd/rave-sp.c + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/nvmem-consumer.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/rave-sp.h> +#include <linux/reboot.h> +#include <linux/slab.h> +#include <linux/watchdog.h> + +enum { + RAVE_SP_RESET_BYTE = 1, + RAVE_SP_RESET_REASON_NORMAL = 0, + RAVE_SP_RESET_DELAY_MS = 500, +}; + +/** + * struct rave_sp_wdt_variant - RAVE SP watchdog variant + * + * @max_timeout: Largest possible watchdog timeout setting + * @min_timeout: Smallest possible watchdog timeout setting + * + * @configure: Function to send configuration command + * @restart: Function to send "restart" command + */ +struct rave_sp_wdt_variant { + unsigned int max_timeout; + unsigned int min_timeout; + + int (*configure)(struct watchdog_device *, bool); + int (*restart)(struct watchdog_device *); +}; + +/** + * struct rave_sp_wdt - RAVE SP watchdog + * + * @wdd: Underlying watchdog device + * @sp: Pointer to parent RAVE SP device + * @variant: Device specific variant information + * @reboot_notifier: Reboot notifier implementing machine reset + */ +struct rave_sp_wdt { + struct watchdog_device wdd; + struct rave_sp *sp; + const struct rave_sp_wdt_variant *variant; + struct notifier_block reboot_notifier; +}; + +static struct rave_sp_wdt *to_rave_sp_wdt(struct watchdog_device *wdd) +{ + return container_of(wdd, struct rave_sp_wdt, wdd); +} + +static int rave_sp_wdt_exec(struct watchdog_device *wdd, void *data, + size_t data_size) +{ + return rave_sp_exec(to_rave_sp_wdt(wdd)->sp, + data, data_size, NULL, 0); +} + +static int rave_sp_wdt_legacy_configure(struct watchdog_device *wdd, bool on) +{ + u8 cmd[] = { + [0] = RAVE_SP_CMD_SW_WDT, + [1] = 0, + [2] = 0, + [3] = on, + [4] = on ? wdd->timeout : 0, + }; + + return rave_sp_wdt_exec(wdd, cmd, sizeof(cmd)); +} + +static int rave_sp_wdt_rdu_configure(struct watchdog_device *wdd, bool on) +{ + u8 cmd[] = { + [0] = RAVE_SP_CMD_SW_WDT, + [1] = 0, + [2] = on, + [3] = (u8)wdd->timeout, + [4] = (u8)(wdd->timeout >> 8), + }; + + return rave_sp_wdt_exec(wdd, cmd, sizeof(cmd)); +} + +/** + * rave_sp_wdt_configure - Configure watchdog device + * + * @wdd: Device to configure + * @on: Desired state of the watchdog timer (ON/OFF) + * + * This function configures two aspects of the watchdog timer: + * + * - Wheither it is ON or OFF + * - Its timeout duration + * + * with first aspect specified via function argument and second via + * the value of 'wdd->timeout'. + */ +static int rave_sp_wdt_configure(struct watchdog_device *wdd, bool on) +{ + return to_rave_sp_wdt(wdd)->variant->configure(wdd, on); +} + +static int rave_sp_wdt_legacy_restart(struct watchdog_device *wdd) +{ + u8 cmd[] = { + [0] = RAVE_SP_CMD_RESET, + [1] = 0, + [2] = RAVE_SP_RESET_BYTE + }; + + return rave_sp_wdt_exec(wdd, cmd, sizeof(cmd)); +} + +static int rave_sp_wdt_rdu_restart(struct watchdog_device *wdd) +{ + u8 cmd[] = { + [0] = RAVE_SP_CMD_RESET, + [1] = 0, + [2] = RAVE_SP_RESET_BYTE, + [3] = RAVE_SP_RESET_REASON_NORMAL + }; + + return rave_sp_wdt_exec(wdd, cmd, sizeof(cmd)); +} + +static int rave_sp_wdt_reboot_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + /* + * Restart handler is called in atomic context which means we + * can't communicate to SP via UART. Luckily for use SP will + * wait 500ms before actually resetting us, so we ask it to do + * so here and let the rest of the system go on wrapping + * things up. + */ + if (action == SYS_DOWN || action == SYS_HALT) { + struct rave_sp_wdt *sp_wd = + container_of(nb, struct rave_sp_wdt, reboot_notifier); + + const int ret = sp_wd->variant->restart(&sp_wd->wdd); + + if (ret < 0) + dev_err(sp_wd->wdd.parent, + "Failed to issue restart command (%d)", ret); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static int rave_sp_wdt_restart(struct watchdog_device *wdd, + unsigned long action, void *data) +{ + /* + * The actual work was done by reboot notifier above. SP + * firmware waits 500 ms before issuing reset, so let's hang + * here for twice that delay and hopefuly we'd never reach + * the return statement. + */ + mdelay(2 * RAVE_SP_RESET_DELAY_MS); + + return -EIO; +} + +static int rave_sp_wdt_start(struct watchdog_device *wdd) +{ + set_bit(WDOG_HW_RUNNING, &wdd->status); + + return rave_sp_wdt_configure(wdd, true); +} + +static int rave_sp_wdt_stop(struct watchdog_device *wdd) +{ + return rave_sp_wdt_configure(wdd, false); +} + +static int rave_sp_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + wdd->timeout = timeout; + + return rave_sp_wdt_configure(wdd, watchdog_hw_running(wdd)); +} + +static int rave_sp_wdt_ping(struct watchdog_device *wdd) +{ + u8 cmd[] = { + [0] = RAVE_SP_CMD_PET_WDT, + [1] = 0, + }; + + return rave_sp_wdt_exec(wdd, cmd, sizeof(cmd)); +} + +static const struct watchdog_info rave_sp_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "RAVE SP Watchdog", +}; + +static const struct watchdog_ops rave_sp_wdt_ops = { + .owner = THIS_MODULE, + .start = rave_sp_wdt_start, + .stop = rave_sp_wdt_stop, + .ping = rave_sp_wdt_ping, + .set_timeout = rave_sp_wdt_set_timeout, + .restart = rave_sp_wdt_restart, +}; + +static const struct of_device_id rave_sp_wdt_of_match[] = { + { .compatible = "zii,rave-sp-watchdog" }, + {} +}; + +static const struct rave_sp_wdt_variant rave_sp_wdt_legacy = { + .max_timeout = 255, + .min_timeout = 1, + .configure = rave_sp_wdt_legacy_configure, + .restart = rave_sp_wdt_legacy_restart, +}; + +static const struct rave_sp_wdt_variant rave_sp_wdt_rdu = { + .max_timeout = 180, + .min_timeout = 60, + .configure = rave_sp_wdt_rdu_configure, + .restart = rave_sp_wdt_rdu_restart, +}; + +static const struct of_device_id rave_sp_wdt_variants[] = { + { .compatible = COMPATIBLE_RAVE_SP_NIU, .data = &rave_sp_wdt_legacy }, + { .compatible = COMPATIBLE_RAVE_SP_MEZZ, .data = &rave_sp_wdt_legacy }, + { .compatible = COMPATIBLE_RAVE_SP_ESB, .data = &rave_sp_wdt_legacy }, + { .compatible = COMPATIBLE_RAVE_SP_RDU1, .data = &rave_sp_wdt_rdu }, + { .compatible = COMPATIBLE_RAVE_SP_RDU2, .data = &rave_sp_wdt_rdu }, + { /* sentinel */ } +}; + +static int rave_sp_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct of_device_id *id; + struct watchdog_device *wdd; + struct rave_sp_wdt *sp_wd; + struct nvmem_cell *cell; + __le16 timeout = 0; + int ret; + + id = of_match_device(rave_sp_wdt_variants, dev->parent); + if (WARN_ON(!id)) + return -ENODEV; + + sp_wd = devm_kzalloc(dev, sizeof(*sp_wd), GFP_KERNEL); + if (!sp_wd) + return -ENOMEM; + + sp_wd->variant = id->data; + sp_wd->sp = dev_get_drvdata(dev->parent); + + wdd = &sp_wd->wdd; + wdd->parent = dev; + wdd->info = &rave_sp_wdt_info; + wdd->ops = &rave_sp_wdt_ops; + wdd->min_timeout = sp_wd->variant->min_timeout; + wdd->max_timeout = sp_wd->variant->max_timeout; + wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS; + wdd->timeout = 60; + + cell = nvmem_cell_get(dev, "wdt-timeout"); + if (!IS_ERR(cell)) { + size_t len; + void *value = nvmem_cell_read(cell, &len); + + if (!IS_ERR(value)) { + memcpy(&timeout, value, min(len, sizeof(timeout))); + kfree(value); + } + nvmem_cell_put(cell); + } + watchdog_init_timeout(wdd, le16_to_cpu(timeout), dev); + watchdog_set_restart_priority(wdd, 255); + + sp_wd->reboot_notifier.notifier_call = rave_sp_wdt_reboot_notifier; + ret = devm_register_reboot_notifier(dev, &sp_wd->reboot_notifier); + if (ret) { + dev_err(dev, "Failed to register reboot notifier\n"); + return ret; + } + + /* + * We don't know if watchdog is running now. To be sure, let's + * start it and depend on watchdog core to ping it + */ + wdd->max_hw_heartbeat_ms = wdd->max_timeout * 1000; + ret = rave_sp_wdt_start(wdd); + if (ret) { + dev_err(dev, "Watchdog didn't start\n"); + return ret; + } + + return devm_watchdog_register_device(dev, wdd); +} + +static struct platform_driver rave_sp_wdt_driver = { + .probe = rave_sp_wdt_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = rave_sp_wdt_of_match, + }, +}; + +module_platform_driver(rave_sp_wdt_driver); + +MODULE_DEVICE_TABLE(of, rave_sp_wdt_of_match); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@xxxxxxxxxxxxxxxxxx>"); +MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>"); +MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@xxxxxxxxx>"); +MODULE_DESCRIPTION("RAVE SP Watchdog driver"); +MODULE_ALIAS("platform:rave-sp-watchdog"); -- 2.13.5 -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
