diff options
| -rw-r--r-- | arch/arm/configs/bcm_defconfig | 2 | ||||
| -rw-r--r-- | drivers/watchdog/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/bcm_kona_wdt.c | 268 |
4 files changed, 283 insertions, 0 deletions
diff --git a/arch/arm/configs/bcm_defconfig b/arch/arm/configs/bcm_defconfig index 2c38fdf..fc3afd8 100644 --- a/arch/arm/configs/bcm_defconfig +++ b/arch/arm/configs/bcm_defconfig @@ -126,3 +126,5 @@ CONFIG_CRC7=y CONFIG_XZ_DEC=y CONFIG_AVERAGE=y CONFIG_PINCTRL_CAPRI=y +CONFIG_WATCHDOG=y +CONFIG_BCM_KONA_WDT=y diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 5be6e91..042e452 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1139,6 +1139,18 @@ 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 LANTIQ_WDT tristate "Lantiq SoC watchdog" depends on LANTIQ diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 91bd95a..af22516 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -57,6 +57,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_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..7e41a83 --- /dev/null +++ b/drivers/watchdog/bcm_kona_wdt.c @@ -0,0 +1,268 @@ +/* + * 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/delay.h> +#include <linux/err.h> +#include <linux/io.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; +}; + +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); + + /* 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; +} + +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; + } + + dev_dbg(dev, "Broadcom Kona Watchdog Timer"); + + return 0; +} + +static int bcm_kona_wdt_remove(struct platform_device *pdev) +{ + 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"); |
