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![Uwe Kleine-König](/assets/img/avatar_default.png)
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230303213716.2123717-30-u.kleine-koenig@pengutronix.de Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
252 lines
6.3 KiB
C
252 lines
6.3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Watchdog driver for the SA11x0/PXA2xx
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*
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* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
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* Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
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*
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* Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
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* warranty for any of this software. This material is provided
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* "AS-IS" and at no charge.
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*
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* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
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*
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* 27/11/2000 Initial release
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/clk.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/platform_device.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/bitops.h>
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#include <linux/uaccess.h>
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#include <linux/timex.h>
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#define REG_OSMR0 0x0000 /* OS timer Match Reg. 0 */
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#define REG_OSMR1 0x0004 /* OS timer Match Reg. 1 */
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#define REG_OSMR2 0x0008 /* OS timer Match Reg. 2 */
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#define REG_OSMR3 0x000c /* OS timer Match Reg. 3 */
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#define REG_OSCR 0x0010 /* OS timer Counter Reg. */
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#define REG_OSSR 0x0014 /* OS timer Status Reg. */
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#define REG_OWER 0x0018 /* OS timer Watch-dog Enable Reg. */
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#define REG_OIER 0x001C /* OS timer Interrupt Enable Reg. */
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#define OSSR_M3 (1 << 3) /* Match status channel 3 */
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#define OSSR_M2 (1 << 2) /* Match status channel 2 */
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#define OSSR_M1 (1 << 1) /* Match status channel 1 */
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#define OSSR_M0 (1 << 0) /* Match status channel 0 */
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#define OWER_WME (1 << 0) /* Watchdog Match Enable */
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#define OIER_E3 (1 << 3) /* Interrupt enable channel 3 */
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#define OIER_E2 (1 << 2) /* Interrupt enable channel 2 */
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#define OIER_E1 (1 << 1) /* Interrupt enable channel 1 */
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#define OIER_E0 (1 << 0) /* Interrupt enable channel 0 */
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static unsigned long oscr_freq;
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static unsigned long sa1100wdt_users;
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static unsigned int pre_margin;
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static int boot_status;
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static void __iomem *reg_base;
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static inline void sa1100_wr(u32 val, u32 offset)
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{
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writel_relaxed(val, reg_base + offset);
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}
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static inline u32 sa1100_rd(u32 offset)
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{
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return readl_relaxed(reg_base + offset);
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}
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/*
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* Allow only one person to hold it open
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*/
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static int sa1100dog_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(1, &sa1100wdt_users))
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return -EBUSY;
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/* Activate SA1100 Watchdog timer */
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sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
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sa1100_wr(OSSR_M3, REG_OSSR);
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sa1100_wr(OWER_WME, REG_OWER);
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sa1100_wr(sa1100_rd(REG_OIER) | OIER_E3, REG_OIER);
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return stream_open(inode, file);
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}
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/*
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* The watchdog cannot be disabled.
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*
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* Previous comments suggested that turning off the interrupt by
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* clearing REG_OIER[E3] would prevent the watchdog timing out but this
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* does not appear to be true (at least on the PXA255).
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*/
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static int sa1100dog_release(struct inode *inode, struct file *file)
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{
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pr_crit("Device closed - timer will not stop\n");
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clear_bit(1, &sa1100wdt_users);
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return 0;
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}
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static ssize_t sa1100dog_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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if (len)
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/* Refresh OSMR3 timer. */
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sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
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return len;
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}
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static const struct watchdog_info ident = {
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.options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
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| WDIOF_KEEPALIVEPING,
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.identity = "SA1100/PXA255 Watchdog",
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.firmware_version = 1,
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};
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static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret = -ENOTTY;
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int time;
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = copy_to_user(argp, &ident,
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sizeof(ident)) ? -EFAULT : 0;
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break;
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case WDIOC_GETSTATUS:
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ret = put_user(0, p);
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break;
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(boot_status, p);
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break;
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case WDIOC_KEEPALIVE:
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sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
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ret = 0;
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(time, p);
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if (ret)
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break;
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if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) {
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ret = -EINVAL;
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break;
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}
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pre_margin = oscr_freq * time;
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sa1100_wr(sa1100_rd(REG_OSCR) + pre_margin, REG_OSMR3);
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fallthrough;
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case WDIOC_GETTIMEOUT:
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ret = put_user(pre_margin / oscr_freq, p);
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break;
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}
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return ret;
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}
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static const struct file_operations sa1100dog_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = sa1100dog_write,
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.unlocked_ioctl = sa1100dog_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = sa1100dog_open,
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.release = sa1100dog_release,
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};
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static struct miscdevice sa1100dog_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &sa1100dog_fops,
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};
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static int margin = 60; /* (secs) Default is 1 minute */
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static struct clk *clk;
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static int sa1100dog_probe(struct platform_device *pdev)
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{
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int ret;
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int *platform_data;
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struct resource *res;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENXIO;
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reg_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
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ret = PTR_ERR_OR_ZERO(reg_base);
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if (ret)
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return ret;
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clk = clk_get(NULL, "OSTIMER0");
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if (IS_ERR(clk)) {
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pr_err("SA1100/PXA2xx Watchdog Timer: clock not found: %d\n",
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(int) PTR_ERR(clk));
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return PTR_ERR(clk);
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}
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ret = clk_prepare_enable(clk);
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if (ret) {
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pr_err("SA1100/PXA2xx Watchdog Timer: clock failed to prepare+enable: %d\n",
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ret);
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goto err;
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}
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oscr_freq = clk_get_rate(clk);
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platform_data = pdev->dev.platform_data;
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if (platform_data && *platform_data)
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boot_status = WDIOF_CARDRESET;
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pre_margin = oscr_freq * margin;
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ret = misc_register(&sa1100dog_miscdev);
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if (ret == 0) {
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pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
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margin);
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return 0;
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}
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clk_disable_unprepare(clk);
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err:
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clk_put(clk);
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return ret;
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}
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static void sa1100dog_remove(struct platform_device *pdev)
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{
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misc_deregister(&sa1100dog_miscdev);
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clk_disable_unprepare(clk);
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clk_put(clk);
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}
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static struct platform_driver sa1100dog_driver = {
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.driver.name = "sa1100_wdt",
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.probe = sa1100dog_probe,
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.remove_new = sa1100dog_remove,
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};
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module_platform_driver(sa1100dog_driver);
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MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
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MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
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module_param(margin, int, 0);
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MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
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MODULE_LICENSE("GPL");
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