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![Pratyush Anand](/assets/img/avatar_default.png)
/sys/class/watchdog/watchdogn/device/modalias can help to identify the driver/module for a given watchdog node. However, many wdt devices do not set their parent and so, we do not see an entry for device in sysfs for such devices. This patch fixes parent of watchdog_device so that /sys/class/watchdog/watchdogn/device is populated. Exceptions: booke, diag288, octeon, softdog and w83627hf -- They do not have any parent. Not sure, how we can identify driver for these devices. Signed-off-by: Pratyush Anand <panand@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-by: Lee Jones <lee.jones@linaro.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> Acked-by: Maxime Coquelin <maxime.coquelin@st.com> Acked-by: Thierry Reding <treding@nvidia.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
373 lines
9.4 KiB
C
373 lines
9.4 KiB
C
/*
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* Copyright (C) 2013 Broadcom Corporation
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/debugfs.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#define SECWDOG_CTRL_REG 0x00000000
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#define SECWDOG_COUNT_REG 0x00000004
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#define SECWDOG_RESERVED_MASK 0x1dffffff
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#define SECWDOG_WD_LOAD_FLAG 0x10000000
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#define SECWDOG_EN_MASK 0x08000000
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#define SECWDOG_SRSTEN_MASK 0x04000000
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#define SECWDOG_RES_MASK 0x00f00000
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#define SECWDOG_COUNT_MASK 0x000fffff
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#define SECWDOG_MAX_COUNT SECWDOG_COUNT_MASK
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#define SECWDOG_CLKS_SHIFT 20
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#define SECWDOG_MAX_RES 15
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#define SECWDOG_DEFAULT_RESOLUTION 4
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#define SECWDOG_MAX_TRY 1000
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#define SECS_TO_TICKS(x, w) ((x) << (w)->resolution)
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#define TICKS_TO_SECS(x, w) ((x) >> (w)->resolution)
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#define BCM_KONA_WDT_NAME "bcm_kona_wdt"
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struct bcm_kona_wdt {
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void __iomem *base;
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/*
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* One watchdog tick is 1/(2^resolution) seconds. Resolution can take
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* the values 0-15, meaning one tick can be 1s to 30.52us. Our default
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* resolution of 4 means one tick is 62.5ms.
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*
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* The watchdog counter is 20 bits. Depending on resolution, the maximum
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* counter value of 0xfffff expires after about 12 days (resolution 0)
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* down to only 32s (resolution 15). The default resolution of 4 gives
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* us a maximum of about 18 hours and 12 minutes before the watchdog
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* times out.
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*/
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int resolution;
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spinlock_t lock;
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#ifdef CONFIG_BCM_KONA_WDT_DEBUG
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unsigned long busy_count;
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struct dentry *debugfs;
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#endif
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};
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static int secure_register_read(struct bcm_kona_wdt *wdt, uint32_t offset)
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{
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uint32_t val;
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unsigned count = 0;
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/*
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* If the WD_LOAD_FLAG is set, the watchdog counter field is being
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* updated in hardware. Once the WD timer is updated in hardware, it
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* gets cleared.
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*/
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do {
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if (unlikely(count > 1))
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udelay(5);
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val = readl_relaxed(wdt->base + offset);
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count++;
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} while ((val & SECWDOG_WD_LOAD_FLAG) && count < SECWDOG_MAX_TRY);
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#ifdef CONFIG_BCM_KONA_WDT_DEBUG
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/* Remember the maximum number iterations due to WD_LOAD_FLAG */
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if (count > wdt->busy_count)
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wdt->busy_count = count;
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#endif
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/* This is the only place we return a negative value. */
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if (val & SECWDOG_WD_LOAD_FLAG)
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return -ETIMEDOUT;
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/* We always mask out reserved bits. */
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val &= SECWDOG_RESERVED_MASK;
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return val;
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}
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#ifdef CONFIG_BCM_KONA_WDT_DEBUG
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static int bcm_kona_wdt_dbg_show(struct seq_file *s, void *data)
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{
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int ctl_val, cur_val;
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unsigned long flags;
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struct bcm_kona_wdt *wdt = s->private;
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if (!wdt) {
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seq_puts(s, "No device pointer\n");
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return 0;
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}
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spin_lock_irqsave(&wdt->lock, flags);
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ctl_val = secure_register_read(wdt, SECWDOG_CTRL_REG);
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cur_val = secure_register_read(wdt, SECWDOG_COUNT_REG);
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spin_unlock_irqrestore(&wdt->lock, flags);
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if (ctl_val < 0 || cur_val < 0) {
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seq_puts(s, "Error accessing hardware\n");
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} else {
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int ctl, cur, ctl_sec, cur_sec, res;
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ctl = ctl_val & SECWDOG_COUNT_MASK;
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res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT;
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cur = cur_val & SECWDOG_COUNT_MASK;
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ctl_sec = TICKS_TO_SECS(ctl, wdt);
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cur_sec = TICKS_TO_SECS(cur, wdt);
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seq_printf(s,
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"Resolution: %d / %d\n"
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"Control: %d s / %d (%#x) ticks\n"
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"Current: %d s / %d (%#x) ticks\n"
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"Busy count: %lu\n",
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res, wdt->resolution,
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ctl_sec, ctl, ctl,
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cur_sec, cur, cur,
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wdt->busy_count);
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}
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return 0;
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}
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static int bcm_kona_dbg_open(struct inode *inode, struct file *file)
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{
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return single_open(file, bcm_kona_wdt_dbg_show, inode->i_private);
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}
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static const struct file_operations bcm_kona_dbg_operations = {
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.open = bcm_kona_dbg_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static void bcm_kona_wdt_debug_init(struct platform_device *pdev)
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{
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struct dentry *dir;
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struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev);
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if (!wdt)
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return;
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wdt->debugfs = NULL;
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dir = debugfs_create_dir(BCM_KONA_WDT_NAME, NULL);
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if (IS_ERR_OR_NULL(dir))
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return;
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if (debugfs_create_file("info", S_IFREG | S_IRUGO, dir, wdt,
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&bcm_kona_dbg_operations))
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wdt->debugfs = dir;
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else
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debugfs_remove_recursive(dir);
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}
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static void bcm_kona_wdt_debug_exit(struct platform_device *pdev)
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{
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struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev);
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if (wdt && wdt->debugfs) {
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debugfs_remove_recursive(wdt->debugfs);
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wdt->debugfs = NULL;
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}
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}
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#else
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static void bcm_kona_wdt_debug_init(struct platform_device *pdev) {}
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static void bcm_kona_wdt_debug_exit(struct platform_device *pdev) {}
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#endif /* CONFIG_BCM_KONA_WDT_DEBUG */
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static int bcm_kona_wdt_ctrl_reg_modify(struct bcm_kona_wdt *wdt,
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unsigned mask, unsigned newval)
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{
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int val;
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unsigned long flags;
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int ret = 0;
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spin_lock_irqsave(&wdt->lock, flags);
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val = secure_register_read(wdt, SECWDOG_CTRL_REG);
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if (val < 0) {
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ret = val;
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} else {
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val &= ~mask;
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val |= newval;
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writel_relaxed(val, wdt->base + SECWDOG_CTRL_REG);
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}
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spin_unlock_irqrestore(&wdt->lock, flags);
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return ret;
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}
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static int bcm_kona_wdt_set_resolution_reg(struct bcm_kona_wdt *wdt)
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{
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if (wdt->resolution > SECWDOG_MAX_RES)
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return -EINVAL;
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return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_RES_MASK,
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wdt->resolution << SECWDOG_CLKS_SHIFT);
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}
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static int bcm_kona_wdt_set_timeout_reg(struct watchdog_device *wdog,
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unsigned watchdog_flags)
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{
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struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog);
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return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_COUNT_MASK,
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SECS_TO_TICKS(wdog->timeout, wdt) |
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watchdog_flags);
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}
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static int bcm_kona_wdt_set_timeout(struct watchdog_device *wdog,
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unsigned int t)
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{
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wdog->timeout = t;
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return 0;
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}
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static unsigned int bcm_kona_wdt_get_timeleft(struct watchdog_device *wdog)
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{
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struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog);
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int val;
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unsigned long flags;
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spin_lock_irqsave(&wdt->lock, flags);
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val = secure_register_read(wdt, SECWDOG_COUNT_REG);
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spin_unlock_irqrestore(&wdt->lock, flags);
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if (val < 0)
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return val;
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return TICKS_TO_SECS(val & SECWDOG_COUNT_MASK, wdt);
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}
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static int bcm_kona_wdt_start(struct watchdog_device *wdog)
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{
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return bcm_kona_wdt_set_timeout_reg(wdog,
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SECWDOG_EN_MASK | SECWDOG_SRSTEN_MASK);
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}
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static int bcm_kona_wdt_stop(struct watchdog_device *wdog)
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{
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struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog);
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return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_EN_MASK |
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SECWDOG_SRSTEN_MASK, 0);
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}
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static struct watchdog_ops bcm_kona_wdt_ops = {
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.owner = THIS_MODULE,
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.start = bcm_kona_wdt_start,
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.stop = bcm_kona_wdt_stop,
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.set_timeout = bcm_kona_wdt_set_timeout,
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.get_timeleft = bcm_kona_wdt_get_timeleft,
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};
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static struct watchdog_info bcm_kona_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
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WDIOF_KEEPALIVEPING,
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.identity = "Broadcom Kona Watchdog Timer",
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};
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static struct watchdog_device bcm_kona_wdt_wdd = {
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.info = &bcm_kona_wdt_info,
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.ops = &bcm_kona_wdt_ops,
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.min_timeout = 1,
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.max_timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION,
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.timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION,
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};
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static void bcm_kona_wdt_shutdown(struct platform_device *pdev)
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{
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bcm_kona_wdt_stop(&bcm_kona_wdt_wdd);
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}
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static int bcm_kona_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct bcm_kona_wdt *wdt;
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struct resource *res;
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int ret;
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wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
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if (!wdt)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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wdt->base = devm_ioremap_resource(dev, res);
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if (IS_ERR(wdt->base))
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return -ENODEV;
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wdt->resolution = SECWDOG_DEFAULT_RESOLUTION;
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ret = bcm_kona_wdt_set_resolution_reg(wdt);
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if (ret) {
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dev_err(dev, "Failed to set resolution (error: %d)", ret);
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return ret;
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}
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spin_lock_init(&wdt->lock);
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platform_set_drvdata(pdev, wdt);
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watchdog_set_drvdata(&bcm_kona_wdt_wdd, wdt);
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bcm_kona_wdt_wdd.parent = &pdev->dev;
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ret = bcm_kona_wdt_set_timeout_reg(&bcm_kona_wdt_wdd, 0);
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if (ret) {
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dev_err(dev, "Failed set watchdog timeout");
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return ret;
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}
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ret = watchdog_register_device(&bcm_kona_wdt_wdd);
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if (ret) {
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dev_err(dev, "Failed to register watchdog device");
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return ret;
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}
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bcm_kona_wdt_debug_init(pdev);
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dev_dbg(dev, "Broadcom Kona Watchdog Timer");
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return 0;
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}
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static int bcm_kona_wdt_remove(struct platform_device *pdev)
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{
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bcm_kona_wdt_debug_exit(pdev);
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bcm_kona_wdt_shutdown(pdev);
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watchdog_unregister_device(&bcm_kona_wdt_wdd);
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dev_dbg(&pdev->dev, "Watchdog driver disabled");
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return 0;
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}
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static const struct of_device_id bcm_kona_wdt_of_match[] = {
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{ .compatible = "brcm,kona-wdt", },
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{},
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};
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MODULE_DEVICE_TABLE(of, bcm_kona_wdt_of_match);
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static struct platform_driver bcm_kona_wdt_driver = {
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.driver = {
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.name = BCM_KONA_WDT_NAME,
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.of_match_table = bcm_kona_wdt_of_match,
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},
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.probe = bcm_kona_wdt_probe,
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.remove = bcm_kona_wdt_remove,
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.shutdown = bcm_kona_wdt_shutdown,
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};
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module_platform_driver(bcm_kona_wdt_driver);
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MODULE_ALIAS("platform:" BCM_KONA_WDT_NAME);
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MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
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MODULE_DESCRIPTION("Broadcom Kona Watchdog Driver");
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MODULE_LICENSE("GPL v2");
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