[PATCH 9/10] watchdog: bcm63xx_wdt: Use bcm63xx_timer interrupt directly

Simon Arlott
2015-11-22T14:12:55Z

There is only one user of bcm63xx_timer and that is the watchdog.
To allow the watchdog driver to be used on machine types other than
mach-bcm63xx, it needs to use an interrupt instead of a custom register
function.

Modify bcm63xx_timer to only disable the timers (so that they don't
interfere with the watchdog if an interrupt occurs) and remove its
exported functions.

Use the timer interrupt directly in bcm63xx_wdt.

Signed-off-by: Simon Arlott <simon-A6De1vDTPLDsq35pWSNszA@public.gmane.org>
---
arch/mips/bcm63xx/dev-wdt.c | 7 +
arch/mips/bcm63xx/timer.c | 181 +--------------------
arch/mips/include/asm/mach-bcm63xx/bcm63xx_timer.h | 11 --
drivers/watchdog/bcm63xx_wdt.c | 45 +++--
4 files changed, 38 insertions(+), 206 deletions(-)
delete mode 100644 arch/mips/include/asm/mach-bcm63xx/bcm63xx_timer.h

diff --git a/arch/mips/bcm63xx/dev-wdt.c b/arch/mips/bcm63xx/dev-wdt.c
index 2a2346a..a7a5497 100644
--- a/arch/mips/bcm63xx/dev-wdt.c
+++ b/arch/mips/bcm63xx/dev-wdt.c
@@ -17,6 +17,11 @@ static struct resource wdt_resources[] = {
.end = -1, /* filled at runtime */
.flags = IORESOURCE_MEM,
},
+ {
+ .start = -1, /* filled at runtime */
+ .end = -1, /* filled at runtime */
+ .flags = IORESOURCE_IRQ,
+ },
};

static struct platform_device bcm63xx_wdt_device = {
@@ -32,6 +37,8 @@ int __init bcm63xx_wdt_register(void)
wdt_resources[0].end = wdt_resources[0].start;
wdt_resources[0].end += RSET_WDT_SIZE - 1;

+ wdt_resources[1].start = bcm63xx_get_irq_number(IRQ_TIMER);
+
return platform_device_register(&bcm63xx_wdt_device);
}
arch_initcall(bcm63xx_wdt_register);
diff --git a/arch/mips/bcm63xx/timer.c b/arch/mips/bcm63xx/timer.c
index 5f11359..9c7b41a6 100644
--- a/arch/mips/bcm63xx/timer.c
+++ b/arch/mips/bcm63xx/timer.c
@@ -9,196 +9,23 @@
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/interrupt.h>
-#include <linux/clk.h>
#include <bcm63xx_cpu.h>
#include <bcm63xx_io.h>
-#include <bcm63xx_timer.h>
#include <bcm63xx_regs.h>

-static DEFINE_RAW_SPINLOCK(timer_reg_lock);
-static DEFINE_RAW_SPINLOCK(timer_data_lock);
-static struct clk *periph_clk;
-
-static struct timer_data {
- void (*cb)(void *);
- void *data;
-} timer_data[BCM63XX_TIMER_COUNT];
-
-static irqreturn_t timer_interrupt(int irq, void *dev_id)
-{
- u32 stat;
- int i;
-
- raw_spin_lock(&timer_reg_lock);
- stat = bcm_timer_readl(TIMER_IRQSTAT_REG);
- bcm_timer_writel(stat, TIMER_IRQSTAT_REG);
- raw_spin_unlock(&timer_reg_lock);
-
- for (i = 0; i < BCM63XX_TIMER_COUNT; i++) {
- if (!(stat & TIMER_IRQSTAT_TIMER_CAUSE(i)))
- continue;
-
- raw_spin_lock(&timer_data_lock);
- if (!timer_data[i].cb) {
- raw_spin_unlock(&timer_data_lock);
- continue;
- }
-
- timer_data[i].cb(timer_data[i].data);
- raw_spin_unlock(&timer_data_lock);
- }
-
- return IRQ_HANDLED;
-}
-
-int bcm63xx_timer_enable(int id)
-{
- u32 reg;
- unsigned long flags;
-
- if (id >= BCM63XX_TIMER_COUNT)
- return -EINVAL;
-
- raw_spin_lock_irqsave(&timer_reg_lock, flags);
-
- reg = bcm_timer_readl(TIMER_CTLx_REG(id));
- reg |= TIMER_CTL_ENABLE_MASK;
- bcm_timer_writel(reg, TIMER_CTLx_REG(id));
-
- reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
- reg |= TIMER_IRQSTAT_TIMER_IR_EN(id);
- bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
-
- raw_spin_unlock_irqrestore(&timer_reg_lock, flags);
- return 0;
-}
-
-EXPORT_SYMBOL(bcm63xx_timer_enable);
-
-int bcm63xx_timer_disable(int id)
+static int bcm63xx_timer_init(void)
{
u32 reg;
- unsigned long flags;
-
- if (id >= BCM63XX_TIMER_COUNT)
- return -EINVAL;
-
- raw_spin_lock_irqsave(&timer_reg_lock, flags);
-
- reg = bcm_timer_readl(TIMER_CTLx_REG(id));
- reg &= ~TIMER_CTL_ENABLE_MASK;
- bcm_timer_writel(reg, TIMER_CTLx_REG(id));
-
- reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
- reg &= ~TIMER_IRQSTAT_TIMER_IR_EN(id);
- bcm_timer_writel(reg, TIMER_IRQSTAT_REG);
-
- raw_spin_unlock_irqrestore(&timer_reg_lock, flags);
- return 0;
-}
-
-EXPORT_SYMBOL(bcm63xx_timer_disable);
-
-int bcm63xx_timer_register(int id, void (*callback)(void *data), void *data)
-{
- unsigned long flags;
- int ret;
-
- if (id >= BCM63XX_TIMER_COUNT || !callback)
- return -EINVAL;
-
- ret = 0;
- raw_spin_lock_irqsave(&timer_data_lock, flags);
- if (timer_data[id].cb) {
- ret = -EBUSY;
- goto out;
- }
-
- timer_data[id].cb = callback;
- timer_data[id].data = data;
-
-out:
- raw_spin_unlock_irqrestore(&timer_data_lock, flags);
- return ret;
-}
-
-EXPORT_SYMBOL(bcm63xx_timer_register);
-
-void bcm63xx_timer_unregister(int id)
-{
- unsigned long flags;
-
- if (id >= BCM63XX_TIMER_COUNT)
- return;
-
- raw_spin_lock_irqsave(&timer_data_lock, flags);
- timer_data[id].cb = NULL;
- raw_spin_unlock_irqrestore(&timer_data_lock, flags);
-}
-
-EXPORT_SYMBOL(bcm63xx_timer_unregister);
-
-unsigned int bcm63xx_timer_countdown(unsigned int countdown_us)
-{
- return (clk_get_rate(periph_clk) / (1000 * 1000)) * countdown_us;
-}
-
-EXPORT_SYMBOL(bcm63xx_timer_countdown);
-
-int bcm63xx_timer_set(int id, int monotonic, unsigned int countdown_us)
-{
- u32 reg, countdown;
- unsigned long flags;
-
- if (id >= BCM63XX_TIMER_COUNT)
- return -EINVAL;
-
- countdown = bcm63xx_timer_countdown(countdown_us);
- if (countdown & ~TIMER_CTL_COUNTDOWN_MASK)
- return -EINVAL;
-
- raw_spin_lock_irqsave(&timer_reg_lock, flags);
- reg = bcm_timer_readl(TIMER_CTLx_REG(id));
-
- if (monotonic)
- reg &= ~TIMER_CTL_MONOTONIC_MASK;
- else
- reg |= TIMER_CTL_MONOTONIC_MASK;
-
- reg &= ~TIMER_CTL_COUNTDOWN_MASK;
- reg |= countdown;
- bcm_timer_writel(reg, TIMER_CTLx_REG(id));
-
- raw_spin_unlock_irqrestore(&timer_reg_lock, flags);
- return 0;
-}
-
-EXPORT_SYMBOL(bcm63xx_timer_set);
-
-int bcm63xx_timer_init(void)
-{
- int ret, irq;
- u32 reg;

+ /* Disable all timers so that they won't interfere with use of the
+ * timer interrupt by the watchdog.
+ */
reg = bcm_timer_readl(TIMER_IRQSTAT_REG);
reg &= ~TIMER_IRQSTAT_TIMER0_IR_EN;
reg &= ~TIMER_IRQSTAT_TIMER1_IR_EN;
reg &= ~TIMER_IRQSTAT_TIMER2_IR_EN;
bcm_timer_writel(reg, TIMER_IRQSTAT_REG);

- periph_clk = clk_get(NULL, "periph");
- if (IS_ERR(periph_clk))
- return -ENODEV;
-
- irq = bcm63xx_get_irq_number(IRQ_TIMER);
- ret = request_irq(irq, timer_interrupt, 0, "bcm63xx_timer", NULL);
- if (ret) {
- printk(KERN_ERR "bcm63xx_timer: failed to register irq\n");
- return ret;
- }
-
return 0;
}

diff --git a/arch/mips/include/asm/mach-bcm63xx/bcm63xx_timer.h b/arch/mips/include/asm/mach-bcm63xx/bcm63xx_timer.h
deleted file mode 100644
index c0fce83..0000000
--- a/arch/mips/include/asm/mach-bcm63xx/bcm63xx_timer.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef BCM63XX_TIMER_H_
-#define BCM63XX_TIMER_H_
-
-int bcm63xx_timer_register(int id, void (*callback)(void *data), void *data);
-void bcm63xx_timer_unregister(int id);
-int bcm63xx_timer_set(int id, int monotonic, unsigned int countdown_us);
-int bcm63xx_timer_enable(int id);
-int bcm63xx_timer_disable(int id);
-unsigned int bcm63xx_timer_countdown(unsigned int countdown_us);
-
-#endif /* !BCM63XX_TIMER_H_ */
diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c
index 7522624..9989efe 100644
--- a/drivers/watchdog/bcm63xx_wdt.c
+++ b/drivers/watchdog/bcm63xx_wdt.c
@@ -17,6 +17,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/errno.h>
+#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -28,9 +29,6 @@
#include <linux/resource.h>
#include <linux/platform_device.h>

-#include <bcm63xx_regs.h>
-#include <bcm63xx_timer.h>
-
#define PFX KBUILD_MODNAME

#define WDT_CLK_NAME "periph"
@@ -40,6 +38,7 @@ struct bcm63xx_wdt_hw {
void __iomem *regs;
struct clk *clk;
unsigned long clock_hz;
+ int irq;
bool running;
};

@@ -96,7 +95,7 @@ static int bcm63xx_wdt_set_timeout(struct watchdog_device *wdd,
}

/* The watchdog interrupt occurs when half the timeout is remaining */
-static void bcm63xx_wdt_isr(void *data)
+static irqreturn_t bcm63xx_wdt_interrupt(int irq, void *data)
{
struct watchdog_device *wdd = data;
struct bcm63xx_wdt_hw *hw = watchdog_get_drvdata(wdd);
@@ -137,6 +136,7 @@ static void bcm63xx_wdt_isr(void *data)
"warning timer fired, reboot in %ums\n", ms);
}
raw_spin_unlock_irqrestore(&hw->lock, flags);
+ return IRQ_HANDLED;
}

static struct watchdog_ops bcm63xx_wdt_ops = {
@@ -229,30 +229,37 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev)
timeleft = 0;
}

- ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, wdd);
+ ret = watchdog_register_device(wdd);
if (ret < 0) {
- dev_err(&pdev->dev, "failed to register wdt timer isr\n");
+ dev_err(&pdev->dev, "failed to register watchdog device\n");
goto disable_clk;
}

- ret = watchdog_register_device(wdd);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed to register watchdog device\n");
- goto unregister_timer;
+ hw->irq = platform_get_irq(pdev, 0);
+ if (hw->irq >= 0) {
+ ret = devm_request_irq(&pdev->dev, hw->irq,
+ bcm63xx_wdt_interrupt, IRQF_TIMER,
+ dev_name(&pdev->dev), wdd);
+ if (ret)
+ hw->irq = -1;
}

- dev_info(&pdev->dev,
- "%s at MMIO 0x%p (timeout = %us, max_timeout = %us)",
- dev_name(wdd->dev), hw->regs,
- wdd->timeout, wdd->max_timeout);
+ if (hw->irq >= 0) {
+ dev_info(&pdev->dev,
+ "%s at MMIO 0x%p (irq = %d, timeout = %us, max_timeout = %us)",
+ dev_name(wdd->dev), hw->regs, hw->irq,
+ wdd->timeout, wdd->max_timeout);
+ } else {
+ dev_info(&pdev->dev,
+ "%s at MMIO 0x%p (timeout = %us, max_timeout = %us)",
+ dev_name(wdd->dev), hw->regs,
+ wdd->timeout, wdd->max_timeout);
+ }

if (timeleft > 0)
dev_alert(wdd->dev, "running, reboot in %us\n", timeleft);
return 0;

-unregister_timer:
- bcm63xx_timer_unregister(TIMER_WDT_ID);
-
disable_clk:
clk_disable_unprepare(hw->clk);
return ret;
@@ -263,7 +270,9 @@ static int bcm63xx_wdt_remove(struct platform_device *pdev)
struct watchdog_device *wdd = platform_get_drvdata(pdev);
struct bcm63xx_wdt_hw *hw = watchdog_get_drvdata(wdd);

- bcm63xx_timer_unregister(TIMER_WDT_ID);
+ if (hw->irq >= 0)
+ devm_free_irq(&pdev->dev, hw->irq, wdd);
+
watchdog_unregister_device(wdd);
clk_disable_unprepare(hw->clk);
return 0;
--
2.1.4