[PATCH v3 6/6] mfd: ahc1ec0-wdt: Add sub-device watchdog for Advantech embedded controller

From: Shihlun Lin
Date: Mon Nov 02 2020 - 02:48:02 EST


This is one of sub-device driver for Advantech embedded controller
AHC1EC0. This driver provide watchdog functionality for Advantech
related applications to restart the system.

Signed-off-by: Shihlun Lin <shihlun.lin@xxxxxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
---
drivers/mfd/Kconfig | 4 +
drivers/mfd/Makefile | 1 +
drivers/mfd/ahc1ec0-wdt.c | 502 ++++++++++++++++++++++++++++++++++++++
3 files changed, 507 insertions(+)
create mode 100644 drivers/mfd/ahc1ec0-wdt.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 52ca49b211fc..b6b2122fb757 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2183,5 +2183,9 @@ config MFD_AHC1EC0_HWMON
driver provides the sysfs attribues for applications to monitor
the system status.

+config MFD_AHC1EC0_WDT
+ tristate "Advantech EC Watchdog Function"
+ depends on MFD_AHC1EC0
+
endmenu
endif
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index eb645db817b5..263e6273729c 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -270,3 +270,4 @@ obj-$(CONFIG_MFD_INTEL_M10_BMC) += intel-m10-bmc.o

obj-$(CONFIG_MFD_AHC1EC0) += ahc1ec0.o
obj-$(CONFIG_MFD_AHC1EC0_HWMON) += ahc1ec0-hwmon.o
+obj-$(CONFIG_MFD_AHC1EC0_WDT) += ahc1ec0-wdt.o
diff --git a/drivers/mfd/ahc1ec0-wdt.c b/drivers/mfd/ahc1ec0-wdt.c
new file mode 100644
index 000000000000..c275b41d873b
--- /dev/null
+++ b/drivers/mfd/ahc1ec0-wdt.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*****************************************************************************
+ * Copyright (c) 2018, Advantech Automation Corp.
+ * THIS IS AN UNPUBLISHED WORK CONTAINING CONFIDENTIAL AND PROPRIETARY
+ * INFORMATION WHICH IS THE PROPERTY OF ADVANTECH AUTOMATION CORP.
+ *
+ * ANY DISCLOSURE, USE, OR REPRODUCTION, WITHOUT WRITTEN AUTHORIZATION FROM
+ * ADVANTECH AUTOMATION CORP., IS STRICTLY PROHIBITED.
+ *****************************************************************************
+ *
+ * File: ahc1ec0-wdt.c
+ * Version: 1.00 <10/10/2014>
+ * Author: Sun.Lang
+ *
+ * Description: The ahc1ec0-wdt is driver for controlling EC watchdog.
+ *
+ *
+ * Status: working
+ *
+ * Change Log:
+ * Version 1.00 <10/10/2014> Sun.Lang
+ * - Initial version
+ * Version 1.01 <12/30/2015> Jiangwei.Zhu
+ * - Modify adv_watchdog_init function to install the driver to
+ * - the support devices.
+ * Version 1.02 <03/04/2016> Jiangwei.Zhu
+ * - Support UNO-1372G-E3AE, TPC-1782H-433AE, APAX-5580-433AE
+ * Version 1.03 <05/09/2016> Ji.Xu
+ * - Support EC watchdog mini-board on UNO-3083G/3085G-D44E/D64E
+ * - APAX-5580-473AE/4C3AE.
+ * - Modify the timeout unit to 1 second.
+ * - Modify the device name check method to fuzzy matching.
+ * Version 1.04 <06/28/2017> Ji.Xu
+ * - Support EC UNO-2271G-E2xAE.
+ * - Support EC UNO-2271G-E02xAE.
+ * - Support EC UNO-2473G-JxAE.
+ * - Support proc filesystem.
+ * Version 1.05 <09/20/2017> Ji.Xu
+ * - Support EC UNO-2484G-633xAE.
+ * - Support EC UNO-2484G-653xAE.
+ * - Support EC UNO-2484G-673xAE.
+ * - Support EC UNO-2484G-733xAE.
+ * - Support EC UNO-2484G-753xAE.
+ * - Support EC UNO-2484G-773xAE.
+ * Version 1.06 <10/26/2017> Ji.Xu
+ * - Support EC UNO-3283G-674AE
+ * - Support EC UNO-3285G-674AE
+ * Version 1.07 <11/16/2017> Zhang.Yang
+ * - Support EC UNO-1372G-J021AE/J031AE
+ * - Support EC UNO-2372G
+ * Version 1.08 <02/02/2018> Ji.Xu
+ * - Support EC TPC-B500-6??AE
+ * - Support EC TPC-5???T-6??AE
+ * - Support EC TPC-5???W-6??AE
+ * Version 1.09 <03/20/2018> Ji.Xu
+ * - Support for compiling in kernel-4.10 and below.
+ * Version 1.10 <02/20/2019> Ji.Xu
+ * - Support EC UNO-420
+ * - Support EC TPC-B200-???AE
+ * - Support EC TPC-2???T-???AE
+ * - Support EC TPC-2???W-???AE
+ * Version 1.11 <08/30/2019> Yao.Kang
+ * - Support 32-bit programs on 64-bit kernel
+ * Version 1.12 <12/03/2019> Jianfeng.dai
+ * - Support support UNO-2372G watchdog
+ * Version 1.13 <04/24/2020> Yao.Kang
+ * - Support support UNO-2473G
+ ******************************************************************************/
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <linux/version.h>
+#include <linux/ioctl.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/uaccess.h>
+#include <asm/switch_to.h>
+#include <linux/platform_device.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/mfd/ahc1ec0.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+
+#define ADVANTECH_EC_WDT_VER "1.12"
+#define ADVANTECH_EC_WDT_DATE "04/24/2020"
+
+#define PROCFS_MAX_SIZE 128
+
+static char adv_expect_close;
+static unsigned long advwdt_is_open;
+static unsigned short timeout = 450;
+static unsigned int major;
+struct mutex lock_ioctl;
+
+struct adv_wdt_info {
+ unsigned char chip_name[32];
+ unsigned char is_enable[8];
+ unsigned long current_timeout;
+};
+
+static struct adv_wdt_info wdt_data = {
+ .chip_name = "Advantech Embedded Controller",
+ .is_enable = "No",
+ .current_timeout = 45,
+};
+
+static int wdt_proc_read(struct seq_file *m, void *p);
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+ return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ ++*pos;
+ return NULL;
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+ /*nothing to do*/
+}
+
+static int c_show(struct seq_file *m, void *p)
+{
+ wdt_proc_read(m, p);
+ return 0;
+}
+
+static const struct seq_operations proc_seq_ops = {
+ .show = c_show,
+ .start = c_start,
+ .next = c_next,
+ .stop = c_stop
+};
+
+static int wdt_proc_open(struct inode *inode, struct file *file)
+{
+ int ret;
+ struct seq_file *m;
+
+ ret = seq_open(file, &proc_seq_ops);
+ m = file->private_data;
+ m->private = file->f_path.dentry->d_iname;
+
+ return ret;
+}
+
+static int wdt_proc_read(struct seq_file *m, void *p)
+{
+ unsigned char *chip_name, *is_enable;
+ unsigned long current_timeout = 0;
+
+ chip_name = wdt_data.chip_name;
+ current_timeout = wdt_data.current_timeout;
+ is_enable = wdt_data.is_enable;
+
+ seq_printf(m, "name : %s\n", chip_name);
+ seq_printf(m, "timeout : %ld\n", current_timeout);
+ seq_printf(m, "is_enable : %s\n", is_enable);
+
+ return 0;
+}
+
+static const struct proc_ops fops = {
+ .proc_open = wdt_proc_open,
+ .proc_read = seq_read,
+};
+
+static int wdt_create_proc(char *name)
+{
+ struct proc_dir_entry *wdt_proc_entries;
+ unsigned char proc_name[64] = {0};
+
+ sprintf(proc_name, "%s", name);
+
+ wdt_proc_entries = proc_create(proc_name, 0644, NULL, &fops);
+ if (wdt_proc_entries == NULL) {
+ remove_proc_entry(proc_name, NULL);
+ pr_err("Error: Could not initialize /proc/%s", proc_name);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void wdt_remove_proc(char *name)
+{
+ unsigned char proc_name[64] = {0};
+
+ sprintf(proc_name, "%s", name);
+ remove_proc_entry(proc_name, NULL);
+}
+
+static int set_delay(unsigned short delay_timeout)
+{
+ if (write_hw_ram(EC_RESET_DELAY_TIME_L, delay_timeout & 0x00FF)) {
+ pr_err("Failed to set Watchdog Retset Time Low byte.");
+ return -EINVAL;
+ }
+
+ if (write_hw_ram(EC_RESET_DELAY_TIME_H, (delay_timeout & 0xFF00) >> 8)) {
+ pr_err("Failed to set Watchdog Retset Time Hight byte.");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int advwdt_set_heartbeat(unsigned long t)
+{
+ if (t < 1 || t > 6553)
+ return -EINVAL;
+
+ timeout = (t * 10);
+
+ return 0;
+}
+
+static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ unsigned long new_timeout;
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ int options;
+ static struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = "Advantech WDT"
+ };
+
+ mutex_lock(&lock_ioctl);
+ if (advwdt_is_open < 1) {
+ pr_err("watchdog does not open.");
+ mutex_unlock(&lock_ioctl);
+ return -1;
+ }
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident))) {
+ mutex_unlock(&lock_ioctl);
+ return -EFAULT;
+ }
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ mutex_unlock(&lock_ioctl);
+ return put_user(0, p);
+
+ case WDIOC_KEEPALIVE:
+ if (write_hwram_command(EC_WDT_RESET)) {
+ pr_err("Failed to set Watchdog reset.");
+ return -EINVAL;
+ }
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, (unsigned long *)arg)) {
+ mutex_unlock(&lock_ioctl);
+ return -EFAULT;
+ }
+
+ if (advwdt_set_heartbeat(new_timeout)) {
+ pr_err("Advantch WDT: the input timeout is out of range.");
+ pr_err("Please choose valid data between 1 ~ 6553.");
+ mutex_unlock(&lock_ioctl);
+ return -EINVAL;
+ }
+
+ if (set_delay((unsigned short)(timeout - 1))) {
+ pr_err("Failed to set Watchdog delay.");
+ return -EINVAL;
+ }
+
+ if (write_hwram_command(EC_WDT_START)) {
+ pr_err("Failed to set Watchdog start.");
+ return -EINVAL;
+ }
+
+ wdt_data.is_enable[0] = 'Y';
+ wdt_data.is_enable[1] = 'e';
+ wdt_data.is_enable[2] = 's';
+ wdt_data.current_timeout = timeout / 10;
+ break;
+
+ case WDIOC_GETTIMEOUT:
+ if (timeout == 0) {
+ mutex_unlock(&lock_ioctl);
+ return -EFAULT;
+ }
+ mutex_unlock(&lock_ioctl);
+
+ return put_user(timeout / 10, (unsigned long *)arg);
+
+ case WDIOC_SETOPTIONS:
+ if (get_user(options, p)) {
+ mutex_unlock(&lock_ioctl);
+ return -EFAULT;
+ }
+
+ if (options & WDIOS_DISABLECARD) {
+ if (write_hwram_command(EC_WDT_STOP)) {
+ pr_err("Failed to set Watchdog stop.");
+ return -EINVAL;
+ }
+
+ wdt_data.is_enable[0] = 'N';
+ wdt_data.is_enable[1] = 'o';
+ wdt_data.is_enable[2] = '\0';
+ }
+
+ if (options & WDIOS_ENABLECARD) {
+ if (write_hwram_command(EC_WDT_STOP)) {
+ pr_err("Failed to set Watchdog stop");
+ return -EINVAL;
+ }
+
+ if (set_delay((unsigned short)(timeout-1))) {
+ pr_err("Failed to set Watchdog delay.");
+ return -EINVAL;
+ }
+
+ if (write_hwram_command(EC_WDT_START)) {
+ pr_err("Failed to set Watchdog start.");
+ return -EINVAL;
+ }
+
+ wdt_data.is_enable[0] = 'Y';
+ wdt_data.is_enable[1] = 'e';
+ wdt_data.is_enable[2] = 's';
+ }
+ mutex_unlock(&lock_ioctl);
+
+ return 0;
+
+ default:
+ mutex_unlock(&lock_ioctl);
+ return -ENOTTY;
+ }
+
+ mutex_unlock(&lock_ioctl);
+ return 0;
+}
+
+static int advwdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &advwdt_is_open))
+ return -EBUSY;
+
+ if (write_hwram_command(EC_WDT_STOP)) {
+ pr_err("Failed to set Watchdog stop.");
+ return -EINVAL;
+ }
+ wdt_data.is_enable[0] = 'N';
+ wdt_data.is_enable[1] = 'o';
+ wdt_data.is_enable[2] = '\0';
+ return 0;
+}
+
+static int advwdt_close(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &advwdt_is_open);
+ adv_expect_close = 0;
+
+ return 0;
+}
+
+/* Notifier for system down */
+static int advwdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT) {
+ /* Turn the WDT off */
+ if (write_hwram_command(EC_WDT_STOP)) {
+ pr_err("Failed to set Watchdog stop.");
+ return -EINVAL;
+ }
+ wdt_data.is_enable[0] = 'N';
+ wdt_data.is_enable[1] = 'o';
+ wdt_data.is_enable[2] = '\0';
+ pr_info("%s: notify sys shutdown", __func__);
+ }
+
+ return NOTIFY_DONE;
+}
+
+/* Kernel Interfaces */
+static const struct file_operations advwdt_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = advwdt_ioctl,
+ .compat_ioctl = advwdt_ioctl,
+ .open = advwdt_open,
+ .release = advwdt_close,
+};
+
+/*
+ * The WDT needs to learn about soft shutdowns in order to
+ * turn the timebomb registers off.
+ */
+static struct notifier_block advwdt_notifier = {
+ advwdt_notify_sys,
+ NULL,
+ 0
+};
+
+static struct class *adv_ec_class;
+static dev_t devno;
+
+static int adv_ec_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev;
+
+ mutex_init(&lock_ioctl);
+
+ major = register_chrdev(0, "adv_watchdog", &advwdt_fops);
+ if (major < 0) {
+ pr_err("Advwdt register chrdev failed!");
+ return major;
+ }
+ devno = MKDEV(major, 0);
+ register_reboot_notifier(&advwdt_notifier);
+
+ /* Create /dev/watchdog for userspace access */
+ adv_ec_class = class_create(THIS_MODULE, "adv_watchdog");
+ if (IS_ERR(adv_ec_class)) {
+ pr_err("%s: can't create class", __func__);
+ unregister_chrdev_region(devno, 1);
+ return -1;
+ }
+
+ dev = device_create(adv_ec_class, NULL, devno, NULL, "watchdog");
+ if (IS_ERR(dev)) {
+ pr_err("%s: can't create device watchdog", __func__);
+ unregister_chrdev_region(devno, 1);
+ class_destroy(adv_ec_class);
+ return -1;
+ }
+
+ wdt_create_proc("advwdtinfo");
+ wdt_data.current_timeout = timeout / 10;
+ wdt_data.is_enable[0] = 'N';
+ wdt_data.is_enable[1] = 'o';
+ wdt_data.is_enable[2] = '\0';
+
+ dev_info(&pdev->dev, "Ver:%s, Data:%s, probe done",
+ ADVANTECH_EC_WDT_VER, ADVANTECH_EC_WDT_DATE);
+
+ return 0;
+}
+
+static int adv_ec_wdt_remove(struct platform_device *pdev)
+{
+ int ret;
+
+ ret = write_hwram_command(EC_WDT_STOP);
+ if (ret) {
+ pr_err("Failed to set Watchdog stop.");
+ return ret;
+ }
+
+ wdt_data.is_enable[0] = 'N';
+ wdt_data.is_enable[1] = 'o';
+ wdt_data.is_enable[2] = '\0';
+ clear_bit(0, &advwdt_is_open);
+ adv_expect_close = 0;
+ pr_info("Driver uninstall, set Watchdog stop.");
+
+ device_destroy(adv_ec_class, devno);
+ unregister_chrdev_region(devno, 1);
+ class_destroy(adv_ec_class);
+
+ unregister_reboot_notifier(&advwdt_notifier);
+ unregister_chrdev(major, "adv_watchdog");
+
+ wdt_remove_proc("advwdtinfo");
+
+ return 0;
+}
+
+static struct platform_driver adv_wdt_drv = {
+ .driver = {
+ .name = "adv-ec-wdt",
+ },
+ .probe = adv_ec_wdt_probe,
+ .remove = adv_ec_wdt_remove,
+};
+module_platform_driver(adv_wdt_drv);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Advantech EC Watchdog Driver.");
--
2.17.1