From 112a80d29b529d4057777ac2cb4ec15ff5b6d210 Mon Sep 17 00:00:00 2001 From: Jonas Aaberg Date: Tue, 17 Apr 2012 09:30:33 +0200 Subject: [PATCH] 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 Reviewed-by: Mattias Wallin Signed-off-by: Linus Walleij Signed-off-by: Samuel Ortiz --- drivers/mfd/ab8500-core.c | 38 +++++++++++++++++++++++++------ include/linux/mfd/abx500/ab8500.h | 6 ++++- 2 files changed, 36 insertions(+), 8 deletions(-) diff --git a/drivers/mfd/ab8500-core.c b/drivers/mfd/ab8500-core.c index ae67612317a8..eee95606bdbb 100644 --- a/drivers/mfd/ab8500-core.c +++ b/drivers/mfd/ab8500-core.c @@ -161,9 +161,13 @@ static int set_register_interruptible(struct ab8500 *ab8500, u8 bank, 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 get_register_interruptible(struct ab8500 *ab8500, u8 bank, 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 @@ out: 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 @@ static void ab8500_irq_lock(struct irq_data *data) 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 @@ static void ab8500_irq_sync_unlock(struct irq_data *data) 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 @@ static irqreturn_t ab8500_irq(int irq, void *dev) 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 @@ static irqreturn_t ab8500_irq(int irq, void *dev) handle_nested_irq(ab8500->irq_base + line); value &= ~(1 << bit); + } while (value); } - + atomic_dec(&ab8500->transfer_ongoing); return IRQ_HANDLED; } @@ -411,6 +426,14 @@ static void ab8500_irq_remove(struct ab8500 *ab8500) } } +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 @@ int __devinit ab8500_init(struct ab8500 *ab8500, enum ab8500_version version) 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 d798f5b6a55f..91dd3ef63e99 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 #include struct device; @@ -224,6 +225,7 @@ enum ab8500_version { * @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 ab8500 { 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 @@ extern int __devinit ab8500_init(struct ab8500 *ab8500, 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; -- 2.34.1