* [PATCH v3 0/2] watchdog: bcm281xx: Watchdog Driver
@ 2013-11-19 1:24 Markus Mayer
2013-11-19 1:24 ` [PATCH v3 1/2] " Markus Mayer
2013-11-19 1:24 ` [PATCH v3 2/2] ARM: bcm281xx: watchdog configuration Markus Mayer
0 siblings, 2 replies; 5+ messages in thread
From: Markus Mayer @ 2013-11-19 1:24 UTC (permalink / raw)
To: linux-arm-kernel
This is version 3 of the watchdog driver for the BCM281xx family of mobile
SoCs.
Changes since version 2:
- BCM_KONA_WDT_NAME: "bcm-kona-wdt" -> "bcm_kona_wdt"
- Don't initialize static variable
- Remove '{'/'}' from single-line statements
- busy_count retains the maximum loop count of the longest loop rather
than an over-all maximum
- Use seq_puts() in lieu of seq_printf() in 2 locations
- Removed error message after devm_kzalloc()
- Added MODULE_ALIAS
Changes since version 1:
- Added module name to "help" section in Kconfig A few cosmetic code
- simplifications and fixes Removed most dev_info() calls and changed the
- remaining ones to dev_dbg() Renamed SECWDOG_WD_LOAD_FLAG_MASK to
- SECWDOG_WD_LOAD_FLAG Added some comments to secure_register_read() and
- struct bcm_kona_wdt Added delay to secure_register_read() Reduced maximum
- retry loop from 10000 to 1000 Introduced "busy_count" variable to count
- how often secure_register_read() gets stalled; this is available through
- debugfs Simplified secure_register_read() to return -ETIMEDOUT rather than
- using a variable parameter to indicate a timeout error Got rid of all uses
- of -EAGAIN Fixed return value check for debugfs_create_dir() Simplified
- bcm_kona_wdt_debugfs_init() by getting rid of goto Created new generic
- function bcm_kona_wdt_ctrl_reg_modify() The following functions now use
- bcm_kona_wdt_ctrl_reg_modify():
- bcm_kona_wdt_set_resolution_reg() bcm_kona_wdt_set_timeout_reg()
- bcm_kona_wdt_stop()
- Made bcm_kona_wdt_set_timeout_reg() more generic, so bcm_kona_wdt_start()
can use it Removed MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR)
Markus Mayer (2):
watchdog: bcm281xx: Watchdog Driver
ARM: bcm281xx: watchdog configuration
arch/arm/configs/bcm_defconfig | 3 +
drivers/watchdog/Kconfig | 22 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/bcm_kona_wdt.c | 366 +++++++++++++++++++++++++++++++++++++++
4 files changed, 392 insertions(+)
create mode 100644 drivers/watchdog/bcm_kona_wdt.c
--
1.7.9.5
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v3 1/2] watchdog: bcm281xx: Watchdog Driver
2013-11-19 1:24 [PATCH v3 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
@ 2013-11-19 1:24 ` Markus Mayer
2013-11-19 5:07 ` Guenter Roeck
2013-11-19 1:24 ` [PATCH v3 2/2] ARM: bcm281xx: watchdog configuration Markus Mayer
1 sibling, 1 reply; 5+ messages in thread
From: Markus Mayer @ 2013-11-19 1:24 UTC (permalink / raw)
To: linux-arm-kernel
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>
+#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");
--
1.7.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v3 2/2] ARM: bcm281xx: watchdog configuration
2013-11-19 1:24 [PATCH v3 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
2013-11-19 1:24 ` [PATCH v3 1/2] " Markus Mayer
@ 2013-11-19 1:24 ` Markus Mayer
2013-11-19 5:07 ` Guenter Roeck
1 sibling, 1 reply; 5+ messages in thread
From: Markus Mayer @ 2013-11-19 1:24 UTC (permalink / raw)
To: linux-arm-kernel
This commit enables the watchdog driver for the BCM281xx family of SoCs.
Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
---
arch/arm/configs/bcm_defconfig | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/configs/bcm_defconfig b/arch/arm/configs/bcm_defconfig
index 6e49310..8b98e11 100644
--- a/arch/arm/configs/bcm_defconfig
+++ b/arch/arm/configs/bcm_defconfig
@@ -130,3 +130,6 @@ CONFIG_CRC_ITU_T=y
CONFIG_CRC7=y
CONFIG_XZ_DEC=y
CONFIG_AVERAGE=y
+CONFIG_WATCHDOG=y
+CONFIG_BCM_KONA_WDT=y
+CONFIG_BCM_KONA_WDT_DEBUG=y
--
1.7.9.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v3 1/2] watchdog: bcm281xx: Watchdog Driver
2013-11-19 1:24 ` [PATCH v3 1/2] " Markus Mayer
@ 2013-11-19 5:07 ` Guenter Roeck
0 siblings, 0 replies; 5+ messages in thread
From: Guenter Roeck @ 2013-11-19 5:07 UTC (permalink / raw)
To: linux-arm-kernel
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");
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v3 2/2] ARM: bcm281xx: watchdog configuration
2013-11-19 1:24 ` [PATCH v3 2/2] ARM: bcm281xx: watchdog configuration Markus Mayer
@ 2013-11-19 5:07 ` Guenter Roeck
0 siblings, 0 replies; 5+ messages in thread
From: Guenter Roeck @ 2013-11-19 5:07 UTC (permalink / raw)
To: linux-arm-kernel
On 11/18/2013 05:24 PM, Markus Mayer wrote:
> This commit enables the watchdog driver for the BCM281xx family of SoCs.
>
> Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
> Reviewed-by: Matt Porter <matt.porter@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
> ---
> arch/arm/configs/bcm_defconfig | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm/configs/bcm_defconfig b/arch/arm/configs/bcm_defconfig
> index 6e49310..8b98e11 100644
> --- a/arch/arm/configs/bcm_defconfig
> +++ b/arch/arm/configs/bcm_defconfig
> @@ -130,3 +130,6 @@ CONFIG_CRC_ITU_T=y
> CONFIG_CRC7=y
> CONFIG_XZ_DEC=y
> CONFIG_AVERAGE=y
> +CONFIG_WATCHDOG=y
> +CONFIG_BCM_KONA_WDT=y
> +CONFIG_BCM_KONA_WDT_DEBUG=y
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-11-19 5:07 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2013-11-19 1:24 [PATCH v3 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
2013-11-19 1:24 ` [PATCH v3 1/2] " Markus Mayer
2013-11-19 5:07 ` Guenter Roeck
2013-11-19 1:24 ` [PATCH v3 2/2] ARM: bcm281xx: watchdog configuration Markus Mayer
2013-11-19 5:07 ` Guenter Roeck
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