| Message ID | 1384824250-16727-2-git-send-email-markus.mayer@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 11/18/2013 05:24 PM, Markus Mayer wrote: > This commit adds support for the watchdog timer used on the BCM281xx > family of SoCs. > > Signed-off-by: Markus Mayer <markus.mayer@linaro.org> > Reviewed-by: Matt Porter <matt.porter@linaro.org> > --- > drivers/watchdog/Kconfig | 22 +++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/bcm_kona_wdt.c | 366 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 389 insertions(+) > create mode 100644 drivers/watchdog/bcm_kona_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index d1d53f3..fe8bd21 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -1121,6 +1121,28 @@ config BCM2835_WDT > To compile this driver as a loadable module, choose M here. > The module will be called bcm2835_wdt. > > +config BCM_KONA_WDT > + tristate "BCM Kona Watchdog" > + depends on ARCH_BCM > + select WATCHDOG_CORE > + help > + Support for the watchdog timer on the following Broadcom BCM281xx > + family, which includes BCM11130, BCM11140, BCM11351, BCM28145 and > + BCM28155 variants. > + > + Say 'Y' or 'M' here to enable the driver. The module will be called > + bcm_kona_wdt. > + > +config BCM_KONA_WDT_DEBUG > + bool "DEBUGFS support for BCM Kona Watchdog" > + depends on BCM_KONA_WDT > + help > + If enabled, adds /sys/kernel/debug/bcm-kona-wdt/info which provides > + access to the driver's internal data structures as well as watchdog > + timer hardware registres. > + > + If in doubt, say 'N'. > + > config LANTIQ_WDT > tristate "Lantiq SoC watchdog" > depends on LANTIQ > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 6c5bb27..7c860ca 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -55,6 +55,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o > obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o > obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o > obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o > +obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/bcm_kona_wdt.c b/drivers/watchdog/bcm_kona_wdt.c > new file mode 100644 > index 0000000..f43687f > --- /dev/null > +++ b/drivers/watchdog/bcm_kona_wdt.c > @@ -0,0 +1,366 @@ > +/* > + * Copyright (C) 2013 Broadcom Corporation > + * > + * 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 version 2. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/debugfs.h> > +#include <linux/delay.h> > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/miscdevice.h> This include should no longer be needed. Otherwise, Reviewed-by: Guenter Roeck <linux@roeck-us.net> > +#include <linux/module.h> > +#include <linux/of_address.h> > +#include <linux/platform_device.h> > +#include <linux/watchdog.h> > + > +#define SECWDOG_CTRL_REG 0x00000000 > +#define SECWDOG_COUNT_REG 0x00000004 > + > +#define SECWDOG_RESERVED_MASK 0x1dffffff > +#define SECWDOG_WD_LOAD_FLAG 0x10000000 > +#define SECWDOG_EN_MASK 0x08000000 > +#define SECWDOG_SRSTEN_MASK 0x04000000 > +#define SECWDOG_RES_MASK 0x00f00000 > +#define SECWDOG_COUNT_MASK 0x000fffff > + > +#define SECWDOG_MAX_COUNT SECWDOG_COUNT_MASK > +#define SECWDOG_CLKS_SHIFT 20 > +#define SECWDOG_MAX_RES 15 > +#define SECWDOG_DEFAULT_RESOLUTION 4 > +#define SECWDOG_MAX_TRY 1000 > + > +#define SECS_TO_TICKS(x, w) ((x) << (w)->resolution) > +#define TICKS_TO_SECS(x, w) ((x) >> (w)->resolution) > + > +#define BCM_KONA_WDT_NAME "bcm_kona_wdt" > + > +struct bcm_kona_wdt { > + void __iomem *base; > + /* > + * One watchdog tick is 1/(2^resolution) seconds. Resolution can take > + * the values 0-15, meaning one tick can be 1s to 30.52us. Our default > + * resolution of 4 means one tick is 62.5ms. > + * > + * The watchdog counter is 20 bits. Depending on resolution, the maximum > + * counter value of 0xfffff expires after about 12 days (resolution 0) > + * down to only 32s (resolution 15). The default resolution of 4 gives > + * us a maximum of about 18 hours and 12 minutes before the watchdog > + * times out. > + */ > + int resolution; > + spinlock_t lock; > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG > + struct dentry *debugfs; > +#endif > +}; > + > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG > +static unsigned long busy_count; > +#endif > + > +static int secure_register_read(void __iomem *addr) > +{ > + uint32_t val; > + unsigned count = 0; > + > + /* > + * If the WD_LOAD_FLAG is set, the watchdog counter field is being > + * updated in hardware. Once the WD timer is updated in hardware, it > + * gets cleared. > + */ > + do { > + if (unlikely(count > 1)) > + udelay(5); > + val = readl_relaxed(addr); > + count++; > + } while ((val & SECWDOG_WD_LOAD_FLAG) && count < SECWDOG_MAX_TRY); > + > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG > + /* Remember the maximum number iterations due to WD_LOAD_FLAG */ > + if (count > busy_count) > + busy_count = count; > +#endif > + > + /* This is the only place we return a negative value. */ > + if (val & SECWDOG_WD_LOAD_FLAG) > + return -ETIMEDOUT; > + > + /* We always mask out reserved bits. */ > + val &= SECWDOG_RESERVED_MASK; > + > + return val; > +} > + > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG > + > +static int bcm_kona_wdt_dbg_show(struct seq_file *s, void *data) > +{ > + int ctl_val, cur_val, ret; > + unsigned long flags; > + struct bcm_kona_wdt *wdt = s->private; > + > + if (!wdt) > + return seq_puts(s, "No device pointer\n"); > + > + spin_lock_irqsave(&wdt->lock, flags); > + ctl_val = secure_register_read(wdt->base + SECWDOG_CTRL_REG); > + cur_val = secure_register_read(wdt->base + SECWDOG_COUNT_REG); > + spin_unlock_irqrestore(&wdt->lock, flags); > + > + if (ctl_val < 0 || cur_val < 0) { > + ret = seq_puts(s, "Error accessing hardware\n"); > + } else { > + int ctl, cur, ctl_sec, cur_sec, res; > + > + ctl = ctl_val & SECWDOG_COUNT_MASK; > + res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT; > + cur = cur_val & SECWDOG_COUNT_MASK; > + ctl_sec = TICKS_TO_SECS(ctl, wdt); > + cur_sec = TICKS_TO_SECS(cur, wdt); > + ret = seq_printf(s, "Resolution: %d / %d\n" > + "Control: %d s / %d (%#x) ticks\n" > + "Current: %d s / %d (%#x) ticks\n" > + "Busy count: %lu\n", res, > + wdt->resolution, ctl_sec, ctl, ctl, cur_sec, > + cur, cur, busy_count); > + } > + > + return ret; > +} > + > +static int bcm_kona_dbg_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, bcm_kona_wdt_dbg_show, inode->i_private); > +} > + > +static const struct file_operations bcm_kona_dbg_operations = { > + .open = bcm_kona_dbg_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > +}; > + > +static struct dentry *bcm_kona_wdt_debugfs_init(struct bcm_kona_wdt *wdt, > + struct watchdog_device *wdd) > +{ > + struct dentry *dir; > + > + dir = debugfs_create_dir(BCM_KONA_WDT_NAME, NULL); > + if (IS_ERR_OR_NULL(dir)) > + return NULL; > + > + if (debugfs_create_file("info", S_IFREG | S_IRUGO, dir, wdt, > + &bcm_kona_dbg_operations)) > + return dir; > + > + /* Clean up */ > + debugfs_remove_recursive(dir); > + return NULL; > +} > + > +static void bcm_kona_debugfs_exit(struct dentry *dir) > +{ > + debugfs_remove_recursive(dir); > +} > + > +#endif /* CONFIG_BCM_KONA_WDT_DEBUG */ > + > +static int bcm_kona_wdt_ctrl_reg_modify(struct bcm_kona_wdt *wdt, > + unsigned mask, unsigned newval) > +{ > + int val; > + unsigned long flags; > + int ret = 0; > + > + spin_lock_irqsave(&wdt->lock, flags); > + > + val = secure_register_read(wdt->base + SECWDOG_CTRL_REG); > + if (val < 0) { > + ret = val; > + } else { > + val &= ~mask; > + val |= newval; > + writel_relaxed(val, wdt->base + SECWDOG_CTRL_REG); > + } > + > + spin_unlock_irqrestore(&wdt->lock, flags); > + > + return ret; > +} > + > +static int bcm_kona_wdt_set_resolution_reg(struct bcm_kona_wdt *wdt) > +{ > + if (wdt->resolution > SECWDOG_MAX_RES) > + return -EINVAL; > + > + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_RES_MASK, > + wdt->resolution << SECWDOG_CLKS_SHIFT); > +} > + > +static int bcm_kona_wdt_set_timeout_reg(struct watchdog_device *wdog, > + unsigned watchdog_flags) > +{ > + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); > + > + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_COUNT_MASK, > + SECS_TO_TICKS(wdog->timeout, wdt) | > + watchdog_flags); > +} > + > +static int bcm_kona_wdt_set_timeout(struct watchdog_device *wdog, > + unsigned int t) > +{ > + wdog->timeout = t; > + return 0; > +} > + > +static unsigned int bcm_kona_wdt_get_timeleft(struct watchdog_device *wdog) > +{ > + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); > + int val; > + unsigned long flags; > + > + spin_lock_irqsave(&wdt->lock, flags); > + val = secure_register_read(wdt->base + SECWDOG_COUNT_REG); > + spin_unlock_irqrestore(&wdt->lock, flags); > + > + if (val < 0) > + return val; > + > + return TICKS_TO_SECS(val & SECWDOG_COUNT_MASK, wdt); > +} > + > +static int bcm_kona_wdt_start(struct watchdog_device *wdog) > +{ > + return bcm_kona_wdt_set_timeout_reg(wdog, > + SECWDOG_EN_MASK | SECWDOG_SRSTEN_MASK); > +} > + > +static int bcm_kona_wdt_stop(struct watchdog_device *wdog) > +{ > + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); > + > + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_EN_MASK | > + SECWDOG_SRSTEN_MASK, 0); > +} > + > +static struct watchdog_ops bcm_kona_wdt_ops = { > + .owner = THIS_MODULE, > + .start = bcm_kona_wdt_start, > + .stop = bcm_kona_wdt_stop, > + .set_timeout = bcm_kona_wdt_set_timeout, > + .get_timeleft = bcm_kona_wdt_get_timeleft, > +}; > + > +static struct watchdog_info bcm_kona_wdt_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | > + WDIOF_KEEPALIVEPING, > + .identity = "Broadcom Kona Watchdog Timer", > +}; > + > +static struct watchdog_device bcm_kona_wdt_wdd = { > + .info = &bcm_kona_wdt_info, > + .ops = &bcm_kona_wdt_ops, > + .min_timeout = 1, > + .max_timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION, > + .timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION, > +}; > + > +static void bcm_kona_wdt_shutdown(struct platform_device *pdev) > +{ > + bcm_kona_wdt_stop(&bcm_kona_wdt_wdd); > +} > + > +static int bcm_kona_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct bcm_kona_wdt *wdt; > + struct resource *res; > + int ret; > + > + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); > + if (!wdt) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + wdt->base = devm_ioremap_resource(dev, res); > + if (IS_ERR(wdt->base)) > + return -ENODEV; > + > + wdt->resolution = SECWDOG_DEFAULT_RESOLUTION; > + ret = bcm_kona_wdt_set_resolution_reg(wdt); > + if (ret) { > + dev_err(dev, "Failed to set resolution (error: %d)", ret); > + return ret; > + } > + > + spin_lock_init(&wdt->lock); > + platform_set_drvdata(pdev, wdt); > + watchdog_set_drvdata(&bcm_kona_wdt_wdd, wdt); > + > + ret = bcm_kona_wdt_set_timeout_reg(&bcm_kona_wdt_wdd, 0); > + if (ret) { > + dev_err(dev, "Failed set watchdog timeout"); > + return ret; > + } > + > + ret = watchdog_register_device(&bcm_kona_wdt_wdd); > + if (ret) { > + dev_err(dev, "Failed to register watchdog device"); > + return ret; > + } > + > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG > + wdt->debugfs = bcm_kona_wdt_debugfs_init(wdt, &bcm_kona_wdt_wdd); > +#endif > + dev_dbg(dev, "Broadcom Kona Watchdog Timer"); > + > + return 0; > +} > + > +static int bcm_kona_wdt_remove(struct platform_device *pdev) > +{ > +#ifdef CONFIG_BCM_KONA_WDT_DEBUG > + struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev); > + > + if (wdt->debugfs) > + bcm_kona_debugfs_exit(wdt->debugfs); > +#endif /* CONFIG_BCM_KONA_WDT_DEBUG */ > + bcm_kona_wdt_shutdown(pdev); > + watchdog_unregister_device(&bcm_kona_wdt_wdd); > + dev_dbg(&pdev->dev, "Watchdog driver disabled"); > + > + return 0; > +} > + > +static const struct of_device_id bcm_kona_wdt_of_match[] = { > + { .compatible = "brcm,kona-wdt", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, bcm_kona_wdt_of_match); > + > +static struct platform_driver bcm_kona_wdt_driver = { > + .driver = { > + .name = BCM_KONA_WDT_NAME, > + .owner = THIS_MODULE, > + .of_match_table = bcm_kona_wdt_of_match, > + }, > + .probe = bcm_kona_wdt_probe, > + .remove = bcm_kona_wdt_remove, > + .shutdown = bcm_kona_wdt_shutdown, > +}; > + > +module_platform_driver(bcm_kona_wdt_driver); > + > +MODULE_ALIAS("platform:" BCM_KONA_WDT_NAME); > +MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>"); > +MODULE_DESCRIPTION("Broadcom Kona Watchdog Driver"); > +MODULE_LICENSE("GPL v2"); >
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index d1d53f3..fe8bd21 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1121,6 +1121,28 @@ config BCM2835_WDT To compile this driver as a loadable module, choose M here. The module will be called bcm2835_wdt. +config BCM_KONA_WDT + tristate "BCM Kona Watchdog" + depends on ARCH_BCM + select WATCHDOG_CORE + help + Support for the watchdog timer on the following Broadcom BCM281xx + family, which includes BCM11130, BCM11140, BCM11351, BCM28145 and + BCM28155 variants. + + Say 'Y' or 'M' here to enable the driver. The module will be called + bcm_kona_wdt. + +config BCM_KONA_WDT_DEBUG + bool "DEBUGFS support for BCM Kona Watchdog" + depends on BCM_KONA_WDT + help + If enabled, adds /sys/kernel/debug/bcm-kona-wdt/info which provides + access to the driver's internal data structures as well as watchdog + timer hardware registres. + + If in doubt, say 'N'. + config LANTIQ_WDT tristate "Lantiq SoC watchdog" depends on LANTIQ diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 6c5bb27..7c860ca 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -55,6 +55,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o +obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/bcm_kona_wdt.c b/drivers/watchdog/bcm_kona_wdt.c new file mode 100644 index 0000000..f43687f --- /dev/null +++ b/drivers/watchdog/bcm_kona_wdt.c @@ -0,0 +1,366 @@ +/* + * Copyright (C) 2013 Broadcom Corporation + * + * 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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/debugfs.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> + +#define SECWDOG_CTRL_REG 0x00000000 +#define SECWDOG_COUNT_REG 0x00000004 + +#define SECWDOG_RESERVED_MASK 0x1dffffff +#define SECWDOG_WD_LOAD_FLAG 0x10000000 +#define SECWDOG_EN_MASK 0x08000000 +#define SECWDOG_SRSTEN_MASK 0x04000000 +#define SECWDOG_RES_MASK 0x00f00000 +#define SECWDOG_COUNT_MASK 0x000fffff + +#define SECWDOG_MAX_COUNT SECWDOG_COUNT_MASK +#define SECWDOG_CLKS_SHIFT 20 +#define SECWDOG_MAX_RES 15 +#define SECWDOG_DEFAULT_RESOLUTION 4 +#define SECWDOG_MAX_TRY 1000 + +#define SECS_TO_TICKS(x, w) ((x) << (w)->resolution) +#define TICKS_TO_SECS(x, w) ((x) >> (w)->resolution) + +#define BCM_KONA_WDT_NAME "bcm_kona_wdt" + +struct bcm_kona_wdt { + void __iomem *base; + /* + * One watchdog tick is 1/(2^resolution) seconds. Resolution can take + * the values 0-15, meaning one tick can be 1s to 30.52us. Our default + * resolution of 4 means one tick is 62.5ms. + * + * The watchdog counter is 20 bits. Depending on resolution, the maximum + * counter value of 0xfffff expires after about 12 days (resolution 0) + * down to only 32s (resolution 15). The default resolution of 4 gives + * us a maximum of about 18 hours and 12 minutes before the watchdog + * times out. + */ + int resolution; + spinlock_t lock; +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + struct dentry *debugfs; +#endif +}; + +#ifdef CONFIG_BCM_KONA_WDT_DEBUG +static unsigned long busy_count; +#endif + +static int secure_register_read(void __iomem *addr) +{ + uint32_t val; + unsigned count = 0; + + /* + * If the WD_LOAD_FLAG is set, the watchdog counter field is being + * updated in hardware. Once the WD timer is updated in hardware, it + * gets cleared. + */ + do { + if (unlikely(count > 1)) + udelay(5); + val = readl_relaxed(addr); + count++; + } while ((val & SECWDOG_WD_LOAD_FLAG) && count < SECWDOG_MAX_TRY); + +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + /* Remember the maximum number iterations due to WD_LOAD_FLAG */ + if (count > busy_count) + busy_count = count; +#endif + + /* This is the only place we return a negative value. */ + if (val & SECWDOG_WD_LOAD_FLAG) + return -ETIMEDOUT; + + /* We always mask out reserved bits. */ + val &= SECWDOG_RESERVED_MASK; + + return val; +} + +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + +static int bcm_kona_wdt_dbg_show(struct seq_file *s, void *data) +{ + int ctl_val, cur_val, ret; + unsigned long flags; + struct bcm_kona_wdt *wdt = s->private; + + if (!wdt) + return seq_puts(s, "No device pointer\n"); + + spin_lock_irqsave(&wdt->lock, flags); + ctl_val = secure_register_read(wdt->base + SECWDOG_CTRL_REG); + cur_val = secure_register_read(wdt->base + SECWDOG_COUNT_REG); + spin_unlock_irqrestore(&wdt->lock, flags); + + if (ctl_val < 0 || cur_val < 0) { + ret = seq_puts(s, "Error accessing hardware\n"); + } else { + int ctl, cur, ctl_sec, cur_sec, res; + + ctl = ctl_val & SECWDOG_COUNT_MASK; + res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT; + cur = cur_val & SECWDOG_COUNT_MASK; + ctl_sec = TICKS_TO_SECS(ctl, wdt); + cur_sec = TICKS_TO_SECS(cur, wdt); + ret = seq_printf(s, "Resolution: %d / %d\n" + "Control: %d s / %d (%#x) ticks\n" + "Current: %d s / %d (%#x) ticks\n" + "Busy count: %lu\n", res, + wdt->resolution, ctl_sec, ctl, ctl, cur_sec, + cur, cur, busy_count); + } + + return ret; +} + +static int bcm_kona_dbg_open(struct inode *inode, struct file *file) +{ + return single_open(file, bcm_kona_wdt_dbg_show, inode->i_private); +} + +static const struct file_operations bcm_kona_dbg_operations = { + .open = bcm_kona_dbg_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static struct dentry *bcm_kona_wdt_debugfs_init(struct bcm_kona_wdt *wdt, + struct watchdog_device *wdd) +{ + struct dentry *dir; + + dir = debugfs_create_dir(BCM_KONA_WDT_NAME, NULL); + if (IS_ERR_OR_NULL(dir)) + return NULL; + + if (debugfs_create_file("info", S_IFREG | S_IRUGO, dir, wdt, + &bcm_kona_dbg_operations)) + return dir; + + /* Clean up */ + debugfs_remove_recursive(dir); + return NULL; +} + +static void bcm_kona_debugfs_exit(struct dentry *dir) +{ + debugfs_remove_recursive(dir); +} + +#endif /* CONFIG_BCM_KONA_WDT_DEBUG */ + +static int bcm_kona_wdt_ctrl_reg_modify(struct bcm_kona_wdt *wdt, + unsigned mask, unsigned newval) +{ + int val; + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&wdt->lock, flags); + + val = secure_register_read(wdt->base + SECWDOG_CTRL_REG); + if (val < 0) { + ret = val; + } else { + val &= ~mask; + val |= newval; + writel_relaxed(val, wdt->base + SECWDOG_CTRL_REG); + } + + spin_unlock_irqrestore(&wdt->lock, flags); + + return ret; +} + +static int bcm_kona_wdt_set_resolution_reg(struct bcm_kona_wdt *wdt) +{ + if (wdt->resolution > SECWDOG_MAX_RES) + return -EINVAL; + + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_RES_MASK, + wdt->resolution << SECWDOG_CLKS_SHIFT); +} + +static int bcm_kona_wdt_set_timeout_reg(struct watchdog_device *wdog, + unsigned watchdog_flags) +{ + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); + + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_COUNT_MASK, + SECS_TO_TICKS(wdog->timeout, wdt) | + watchdog_flags); +} + +static int bcm_kona_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int t) +{ + wdog->timeout = t; + return 0; +} + +static unsigned int bcm_kona_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); + int val; + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + val = secure_register_read(wdt->base + SECWDOG_COUNT_REG); + spin_unlock_irqrestore(&wdt->lock, flags); + + if (val < 0) + return val; + + return TICKS_TO_SECS(val & SECWDOG_COUNT_MASK, wdt); +} + +static int bcm_kona_wdt_start(struct watchdog_device *wdog) +{ + return bcm_kona_wdt_set_timeout_reg(wdog, + SECWDOG_EN_MASK | SECWDOG_SRSTEN_MASK); +} + +static int bcm_kona_wdt_stop(struct watchdog_device *wdog) +{ + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); + + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_EN_MASK | + SECWDOG_SRSTEN_MASK, 0); +} + +static struct watchdog_ops bcm_kona_wdt_ops = { + .owner = THIS_MODULE, + .start = bcm_kona_wdt_start, + .stop = bcm_kona_wdt_stop, + .set_timeout = bcm_kona_wdt_set_timeout, + .get_timeleft = bcm_kona_wdt_get_timeleft, +}; + +static struct watchdog_info bcm_kona_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING, + .identity = "Broadcom Kona Watchdog Timer", +}; + +static struct watchdog_device bcm_kona_wdt_wdd = { + .info = &bcm_kona_wdt_info, + .ops = &bcm_kona_wdt_ops, + .min_timeout = 1, + .max_timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION, + .timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION, +}; + +static void bcm_kona_wdt_shutdown(struct platform_device *pdev) +{ + bcm_kona_wdt_stop(&bcm_kona_wdt_wdd); +} + +static int bcm_kona_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bcm_kona_wdt *wdt; + struct resource *res; + int ret; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + wdt->base = devm_ioremap_resource(dev, res); + if (IS_ERR(wdt->base)) + return -ENODEV; + + wdt->resolution = SECWDOG_DEFAULT_RESOLUTION; + ret = bcm_kona_wdt_set_resolution_reg(wdt); + if (ret) { + dev_err(dev, "Failed to set resolution (error: %d)", ret); + return ret; + } + + spin_lock_init(&wdt->lock); + platform_set_drvdata(pdev, wdt); + watchdog_set_drvdata(&bcm_kona_wdt_wdd, wdt); + + ret = bcm_kona_wdt_set_timeout_reg(&bcm_kona_wdt_wdd, 0); + if (ret) { + dev_err(dev, "Failed set watchdog timeout"); + return ret; + } + + ret = watchdog_register_device(&bcm_kona_wdt_wdd); + if (ret) { + dev_err(dev, "Failed to register watchdog device"); + return ret; + } + +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + wdt->debugfs = bcm_kona_wdt_debugfs_init(wdt, &bcm_kona_wdt_wdd); +#endif + dev_dbg(dev, "Broadcom Kona Watchdog Timer"); + + return 0; +} + +static int bcm_kona_wdt_remove(struct platform_device *pdev) +{ +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev); + + if (wdt->debugfs) + bcm_kona_debugfs_exit(wdt->debugfs); +#endif /* CONFIG_BCM_KONA_WDT_DEBUG */ + bcm_kona_wdt_shutdown(pdev); + watchdog_unregister_device(&bcm_kona_wdt_wdd); + dev_dbg(&pdev->dev, "Watchdog driver disabled"); + + return 0; +} + +static const struct of_device_id bcm_kona_wdt_of_match[] = { + { .compatible = "brcm,kona-wdt", }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm_kona_wdt_of_match); + +static struct platform_driver bcm_kona_wdt_driver = { + .driver = { + .name = BCM_KONA_WDT_NAME, + .owner = THIS_MODULE, + .of_match_table = bcm_kona_wdt_of_match, + }, + .probe = bcm_kona_wdt_probe, + .remove = bcm_kona_wdt_remove, + .shutdown = bcm_kona_wdt_shutdown, +}; + +module_platform_driver(bcm_kona_wdt_driver); + +MODULE_ALIAS("platform:" BCM_KONA_WDT_NAME); +MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>"); +MODULE_DESCRIPTION("Broadcom Kona Watchdog Driver"); +MODULE_LICENSE("GPL v2");