* [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver
@ 2013-11-22 22:56 Markus Mayer
2013-11-22 22:56 ` [PATCH v5 1/2] " Markus Mayer
` (3 more replies)
0 siblings, 4 replies; 6+ messages in thread
From: Markus Mayer @ 2013-11-22 22:56 UTC (permalink / raw)
To: linux-arm-kernel
This is version 5 of the watchdog driver for the BCM281xx family of mobile
SoCs.
Changes since version 4:
- Fixed whitespace issue in Kconfig "help" section
- Rebased onto 3.13-rc1 (due to merge conflict in Makefile)
Changes since version 3:
- Removed #include <linux/miscdevice.h>
- Added Reviewed-by:/Acked-by: Guenter Roeck
Changes since version 2:
- BCM_KONA_WDT_NAME: "bcm-kona-wdt" -> "bcm_kona_wdt"
- Don't initialize static variable
- Removed '{'/'}' 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 | 365 +++++++++++++++++++++++++++++++++++++++
4 files changed, 391 insertions(+)
create mode 100644 drivers/watchdog/bcm_kona_wdt.c
--
1.7.9.5
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v5 1/2] watchdog: bcm281xx: Watchdog Driver
2013-11-22 22:56 [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
@ 2013-11-22 22:56 ` Markus Mayer
2013-12-17 21:24 ` Markus Mayer
2013-11-22 22:56 ` [PATCH v5 2/2] ARM: bcm281xx: watchdog configuration Markus Mayer
` (2 subsequent siblings)
3 siblings, 1 reply; 6+ messages in thread
From: Markus Mayer @ 2013-11-22 22:56 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>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
drivers/watchdog/Kconfig | 22 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/bcm_kona_wdt.c | 365 +++++++++++++++++++++++++++++++++++++++
3 files changed, 388 insertions(+)
create mode 100644 drivers/watchdog/bcm_kona_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 5be6e91..24bc93a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1139,6 +1139,28 @@ 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 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..9fe174b
--- /dev/null
+++ b/drivers/watchdog/bcm_kona_wdt.c
@@ -0,0 +1,365 @@
+/*
+ * 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/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] 6+ messages in thread
* [PATCH v5 2/2] ARM: bcm281xx: watchdog configuration
2013-11-22 22:56 [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
2013-11-22 22:56 ` [PATCH v5 1/2] " Markus Mayer
@ 2013-11-22 22:56 ` Markus Mayer
2013-12-06 22:23 ` [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
[not found] ` <20131228204039.GA19982@spo001.leaseweb.com>
3 siblings, 0 replies; 6+ messages in thread
From: Markus Mayer @ 2013-11-22 22:56 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>
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 287ac1d..d4d0083 100644
--- a/arch/arm/configs/bcm_defconfig
+++ b/arch/arm/configs/bcm_defconfig
@@ -126,3 +126,6 @@ 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] 6+ messages in thread
* [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver
2013-11-22 22:56 [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
2013-11-22 22:56 ` [PATCH v5 1/2] " Markus Mayer
2013-11-22 22:56 ` [PATCH v5 2/2] ARM: bcm281xx: watchdog configuration Markus Mayer
@ 2013-12-06 22:23 ` Markus Mayer
[not found] ` <20131228204039.GA19982@spo001.leaseweb.com>
3 siblings, 0 replies; 6+ messages in thread
From: Markus Mayer @ 2013-12-06 22:23 UTC (permalink / raw)
To: linux-arm-kernel
On 22 November 2013 14:56, Markus Mayer <markus.mayer@linaro.org> wrote:
> This is version 5 of the watchdog driver for the BCM281xx family of mobile
> SoCs.
>
> Changes since version 4:
> - Fixed whitespace issue in Kconfig "help" section
> - Rebased onto 3.13-rc1 (due to merge conflict in Makefile)
>
> Changes since version 3:
> - Removed #include <linux/miscdevice.h>
> - Added Reviewed-by:/Acked-by: Guenter Roeck
>
> Changes since version 2:
>
> - BCM_KONA_WDT_NAME: "bcm-kona-wdt" -> "bcm_kona_wdt"
> - Don't initialize static variable
> - Removed '{'/'}' 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 | 365 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 391 insertions(+)
> create mode 100644 drivers/watchdog/bcm_kona_wdt.c
>
> --
> 1.7.9.5
Hi,
This series seems approved and ready to go. I just wanted to
double-check that my understanding is correct and that it will be
queued for 3.14. However, if there is anything you need from me,
please let me know.
Thanks,
-Markus
--
Markus Mayer
Broadcom Landing Team
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v5 1/2] watchdog: bcm281xx: Watchdog Driver
2013-11-22 22:56 ` [PATCH v5 1/2] " Markus Mayer
@ 2013-12-17 21:24 ` Markus Mayer
0 siblings, 0 replies; 6+ messages in thread
From: Markus Mayer @ 2013-12-17 21:24 UTC (permalink / raw)
To: linux-arm-kernel
Hi Wim,
Would you be able to pull v5 of this patch series into
linux-watchdog-next? There haven't been any negative comments for
several weeks.
Thanks,
-Markus
On 22 November 2013 14:56, Markus Mayer <markus.mayer@linaro.org> 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>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> ---
> drivers/watchdog/Kconfig | 22 +++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/bcm_kona_wdt.c | 365 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 388 insertions(+)
> create mode 100644 drivers/watchdog/bcm_kona_wdt.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 5be6e91..24bc93a 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -1139,6 +1139,28 @@ 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 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..9fe174b
> --- /dev/null
> +++ b/drivers/watchdog/bcm_kona_wdt.c
> @@ -0,0 +1,365 @@
> +/*
> + * 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/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
--
Markus Mayer
Broadcom Landing Team
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver
[not found] ` <20131228204039.GA19982@spo001.leaseweb.com>
@ 2013-12-31 18:03 ` Markus Mayer
0 siblings, 0 replies; 6+ messages in thread
From: Markus Mayer @ 2013-12-31 18:03 UTC (permalink / raw)
To: linux-arm-kernel
Hi Wim,
Thanks for your comments. I addressed them and will be sending out the
resulting patches shortly.
> Questions/remarks I still have:
> 1) *debugfs is defined in the bcm_kona_wdt struct, but busy_count isn't.
> Seems odd to me. What's the reason?
secure_register_read() only took a void __iomem * argument, but I
changed that to struct bcm_kona_wdt * and offset. With that change,
busy_count can be part of struct bcm_kona_wdt.
> 2) I don't like the #ifdef pieces in the probe and remove functions.
> The preferred method is to not have the #ifdefs there, but to have an
> init and exit function that is defined in a similar way:
I took care of those. However I opted to pass a struct platform_device
* to the new functions bcm_kona_wdt_debug_init() and
bcm_kona_wdt_debug_exit(). The reason being that bcm_kona_wdt_remove()
didn't have a struct bcm_kona_wdt * outside the #ifdef that I was
about to remove. For consistency, I then used struct platform_device *
for bcm_kona_wdt_debug_init(), as well.
> #ifdef CONFIG_BCM_KONA_WDT_DEBUG
> ...
> static void bcm_kona_wdt_debug_init(struct bcm_kona_wdt *wdt)
> {
> wdt->debugfs = bcm_kona_wdt_debugfs_init(wdt, &bcm_kona_wdt_wdd);
> }
> ...
> #else /* !CONFIG_BCM_KONA_WDT_DEBUG */
> static void bcm_kona_wdt_debug_init(struct bcm_kona_wdt *wdt) {}
> ...
> #endif /* CONFIG_BCM_KONA_WDT_DEBUG */
Now I have a question (or rather a comment) of my own. I noticed that
you "squashed" my two original patches into a single patch before
breaking out the debugfs related code. The side-effect of this was
that two lines of my bcm_defconfig change (CONFIG_WATCHDOG=y and
CONFIG_BCM_KONA_WDT=y) were included in the patch you took into
linux-watchdog-next.
If I understand correctly (and this is why I had broken out the
bcm_defconfig change into a separate patch), a defconfig change would
normally go through the platform maintainer's tree, in this case
Christian, whereas the actual driver would go upstream through your
tree.
I don't think it makes too much of a difference with regards to this
driver where the defconfig change goes. In fact, taking it all through
one tree might even be slightly easier and reduce the chance of
conflicts, but I still think Christian needs to at least be aware of
this change going through the watchdog tree. He owns bcm_defconfig,
after all.
A loosely related comment: gitweb for linux-watchdog-next seems to be
broken: http://www.linux-watchdog.org/cgi-bin/gitweb.cgi?p=linux-watchdog-next.git;a=summary.
I stumbled upon this yesterday when I was trying to look at the
current status of this tree.
In case readers of this e-mail are interested in taking a quick peek
at the parts of the Kona watchdog driver that were already accepted,
without cloning the entire repo, I created a temporary watchdog mirror
with the commit in question available for in-browser viewing at
http://git.linaro.org/people/markus.mayer/watchdog-next-mirror.git/commit/bd90ccd42c5d6317979c62919ba1c79fd34fa785
Regards,
-Markus
--
Markus Mayer
Broadcom Landing Team
^ permalink raw reply [flat|nested] 6+ messages in thread
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2013-11-22 22:56 [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
2013-11-22 22:56 ` [PATCH v5 1/2] " Markus Mayer
2013-12-17 21:24 ` Markus Mayer
2013-11-22 22:56 ` [PATCH v5 2/2] ARM: bcm281xx: watchdog configuration Markus Mayer
2013-12-06 22:23 ` [PATCH v5 0/2] watchdog: bcm281xx: Watchdog Driver Markus Mayer
[not found] ` <20131228204039.GA19982@spo001.leaseweb.com>
2013-12-31 18:03 ` Markus Mayer
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