mfd: Deny ab8500 suspend if i2c transfer is ongoing
If we are in the middle of an I2C transfer we need to deny suspend
of the AB8500 core. Implement an atomic reference counter for the
I2C operations to make sure we don't do this.
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Reviewed-by: Mattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/ab8500-core.c b/drivers/mfd/ab8500-core.c
index ae676123..eee9560 100644
--- a/drivers/mfd/ab8500-core.c
+++ b/drivers/mfd/ab8500-core.c
@@ -161,9 +161,13 @@
static int ab8500_set_register(struct device *dev, u8 bank,
u8 reg, u8 value)
{
+ int ret;
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
- return set_register_interruptible(ab8500, bank, reg, value);
+ atomic_inc(&ab8500->transfer_ongoing);
+ ret = set_register_interruptible(ab8500, bank, reg, value);
+ atomic_dec(&ab8500->transfer_ongoing);
+ return ret;
}
static int get_register_interruptible(struct ab8500 *ab8500, u8 bank,
@@ -192,9 +196,13 @@
static int ab8500_get_register(struct device *dev, u8 bank,
u8 reg, u8 *value)
{
+ int ret;
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
- return get_register_interruptible(ab8500, bank, reg, value);
+ atomic_inc(&ab8500->transfer_ongoing);
+ ret = get_register_interruptible(ab8500, bank, reg, value);
+ atomic_dec(&ab8500->transfer_ongoing);
+ return ret;
}
static int mask_and_set_register_interruptible(struct ab8500 *ab8500, u8 bank,
@@ -241,11 +249,14 @@
static int ab8500_mask_and_set_register(struct device *dev,
u8 bank, u8 reg, u8 bitmask, u8 bitvalues)
{
+ int ret;
struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
- return mask_and_set_register_interruptible(ab8500, bank, reg,
- bitmask, bitvalues);
-
+ atomic_inc(&ab8500->transfer_ongoing);
+ ret= mask_and_set_register_interruptible(ab8500, bank, reg,
+ bitmask, bitvalues);
+ atomic_dec(&ab8500->transfer_ongoing);
+ return ret;
}
static struct abx500_ops ab8500_ops = {
@@ -264,6 +275,7 @@
struct ab8500 *ab8500 = irq_data_get_irq_chip_data(data);
mutex_lock(&ab8500->irq_lock);
+ atomic_inc(&ab8500->transfer_ongoing);
}
static void ab8500_irq_sync_unlock(struct irq_data *data)
@@ -292,7 +304,7 @@
reg = AB8500_IT_MASK1_REG + ab8500->irq_reg_offset[i];
set_register_interruptible(ab8500, AB8500_INTERRUPT, reg, new);
}
-
+ atomic_dec(&ab8500->transfer_ongoing);
mutex_unlock(&ab8500->irq_lock);
}
@@ -332,6 +344,8 @@
dev_vdbg(ab8500->dev, "interrupt\n");
+ atomic_inc(&ab8500->transfer_ongoing);
+
for (i = 0; i < ab8500->mask_size; i++) {
int regoffset = ab8500->irq_reg_offset[i];
int status;
@@ -355,9 +369,10 @@
handle_nested_irq(ab8500->irq_base + line);
value &= ~(1 << bit);
+
} while (value);
}
-
+ atomic_dec(&ab8500->transfer_ongoing);
return IRQ_HANDLED;
}
@@ -411,6 +426,14 @@
}
}
+int ab8500_suspend(struct ab8500 *ab8500)
+{
+ if (atomic_read(&ab8500->transfer_ongoing))
+ return -EINVAL;
+ else
+ return 0;
+}
+
/* AB8500 GPIO Resources */
static struct resource __devinitdata ab8500_gpio_resources[] = {
{
@@ -1059,6 +1082,7 @@
mutex_init(&ab8500->lock);
mutex_init(&ab8500->irq_lock);
+ atomic_set(&ab8500->transfer_ongoing, 0);
if (version != AB8500_VERSION_UNDEFINED)
ab8500->version = version;
diff --git a/include/linux/mfd/abx500/ab8500.h b/include/linux/mfd/abx500/ab8500.h
index d798f5b..91dd3ef 100644
--- a/include/linux/mfd/abx500/ab8500.h
+++ b/include/linux/mfd/abx500/ab8500.h
@@ -7,6 +7,7 @@
#ifndef MFD_AB8500_H
#define MFD_AB8500_H
+#include <linux/atomic.h>
#include <linux/mutex.h>
struct device;
@@ -224,6 +225,7 @@
* @dev: parent device
* @lock: read/write operations lock
* @irq_lock: genirq bus lock
+ * @transfer_ongoing: 0 if no transfer ongoing
* @irq: irq line
* @version: chip version id (e.g. ab8500 or ab9540)
* @chip_id: chip revision id
@@ -242,7 +244,7 @@
struct device *dev;
struct mutex lock;
struct mutex irq_lock;
-
+ atomic_t transfer_ongoing;
int irq_base;
int irq;
enum ab8500_version version;
@@ -288,6 +290,8 @@
enum ab8500_version version);
extern int __devexit ab8500_exit(struct ab8500 *ab8500);
+extern int ab8500_suspend(struct ab8500 *ab8500);
+
static inline int is_ab8500(struct ab8500 *ab)
{
return ab->version == AB8500_VERSION_AB8500;