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Subject[RESEND RFC PATCH 2/2] pinctrl: at91: expose the isr bit
Date
From: Peter Rosin <peda@axentia.se>

This is a bit horrible, as reading the isr register will interfere with
interrupts on other pins in the same pio. So, be careful...

Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/pinctrl/pinctrl-at91.c | 50 ++++++++++++++++++++++++++++++++++++----
1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
index 2deb1309fcac..6ae615264e6a 100644
--- a/drivers/pinctrl/pinctrl-at91.c
+++ b/drivers/pinctrl/pinctrl-at91.c
@@ -16,6 +16,7 @@
#include <linux/of_irq.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
+#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/pinctrl/machine.h>
@@ -40,6 +41,8 @@ struct at91_gpio_chip {
int pioc_hwirq; /* PIO bank interrupt identifier on AIC */
int pioc_virq; /* PIO bank Linux virtual interrupt */
int pioc_idx; /* PIO bank index */
+ spinlock_t isr_lock; /* PIO_ISR cache lock */
+ unsigned isr_cache; /* PIO_ISR cache */
void __iomem *regbase; /* PIO bank virtual address */
struct clk *clock; /* associated clock */
struct at91_pinctrl_mux_ops *ops; /* ops */
@@ -737,7 +740,9 @@ static int at91_pmx_set(struct pinctrl_dev *pctldev, unsigned selector,
continue;

mask = pin_to_mask(pin->pin);
+ spin_lock(&gpio_chips[pin->bank]->isr_lock);
at91_mux_disable_interrupt(pio, mask);
+ spin_unlock(&gpio_chips[pin->bank]->isr_lock);
switch (pin->mux) {
case AT91_MUX_GPIO:
at91_mux_gpio_enable(pio, mask, 1);
@@ -1331,6 +1336,29 @@ static int at91_gpio_get(struct gpio_chip *chip, unsigned offset)
return (pdsr & mask) != 0;
}

+static int at91_gpio_get_isr(struct gpio_chip *chip, unsigned offset)
+{
+ struct at91_gpio_chip *at91_gpio = to_at91_gpio_chip(chip);
+ void __iomem *pio = at91_gpio->regbase;
+ unsigned mask = 1 << offset;
+ int res;
+
+ spin_lock(&at91_gpio->isr_lock);
+ if (readl_relaxed(pio + PIO_IMR)) {
+ /* do not clobber PIO_ISR if any interrupts are enabled */
+ res = -EBUSY;
+ goto out;
+ }
+
+ at91_gpio->isr_cache |= readl_relaxed(pio + PIO_ISR);
+ res = (at91_gpio->isr_cache & mask) != 0;
+ at91_gpio->isr_cache &= ~mask;
+
+ out:
+ spin_unlock(&at91_gpio->isr_lock);
+ return res;
+}
+
static void at91_gpio_set(struct gpio_chip *chip, unsigned offset,
int val)
{
@@ -1425,8 +1453,12 @@ static void gpio_irq_mask(struct irq_data *d)
void __iomem *pio = at91_gpio->regbase;
unsigned mask = 1 << d->hwirq;

- if (pio)
- writel_relaxed(mask, pio + PIO_IDR);
+ if (!pio)
+ return;
+
+ spin_lock(&at91_gpio->isr_lock);
+ writel_relaxed(mask, pio + PIO_IDR);
+ spin_unlock(&at91_gpio->isr_lock);
}

static void gpio_irq_unmask(struct irq_data *d)
@@ -1435,8 +1467,12 @@ static void gpio_irq_unmask(struct irq_data *d)
void __iomem *pio = at91_gpio->regbase;
unsigned mask = 1 << d->hwirq;

- if (pio)
- writel_relaxed(mask, pio + PIO_IER);
+ if (!pio)
+ return;
+
+ spin_lock(&at91_gpio->isr_lock);
+ writel_relaxed(mask, pio + PIO_IER);
+ spin_unlock(&at91_gpio->isr_lock);
}

static int gpio_irq_type(struct irq_data *d, unsigned type)
@@ -1562,8 +1598,10 @@ void at91_pinctrl_gpio_suspend(void)
pio = gpio_chips[i]->regbase;

backups[i] = readl_relaxed(pio + PIO_IMR);
+ spin_lock(&gpio_chips[i]->isr_lock);
writel_relaxed(backups[i], pio + PIO_IDR);
writel_relaxed(wakeups[i], pio + PIO_IER);
+ spin_unlock(&gpio_chips[i]->isr_lock);

if (!wakeups[i])
clk_disable_unprepare(gpio_chips[i]->clock);
@@ -1588,8 +1626,10 @@ void at91_pinctrl_gpio_resume(void)
if (!wakeups[i])
clk_prepare_enable(gpio_chips[i]->clock);

+ spin_lock(&gpio_chips[i]->isr_lock);
writel_relaxed(wakeups[i], pio + PIO_IDR);
writel_relaxed(backups[i], pio + PIO_IER);
+ spin_unlock(&gpio_chips[i]->isr_lock);
}
}

@@ -1713,6 +1753,7 @@ static struct gpio_chip at91_gpio_template = {
.get_direction = at91_gpio_get_direction,
.direction_input = at91_gpio_direction_input,
.get = at91_gpio_get,
+ .get_isr = at91_gpio_get_isr,
.direction_output = at91_gpio_direction_output,
.set = at91_gpio_set,
.set_multiple = at91_gpio_set_multiple,
@@ -1789,6 +1830,7 @@ static int at91_gpio_probe(struct platform_device *pdev)
}

at91_chip->chip = at91_gpio_template;
+ spin_lock_init(&at91_chip->isr_lock);

chip = &at91_chip->chip;
chip->of_node = np;
--
1.7.10.4


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