First round of IIO fixes for 3.12

A series of wrong 'struct dev' assumptions in suspend/resume callbacks
 following on from this issue being identified in a new driver review.
 One to watch out for in future.
 
 A number of driver specific fixes
 1) at91 - fix a overflow in clock rate computation
 2) dummy - Kconfig dependency issue
 3) isl29018 - uninitialized value
 4) hmc5843 - measurement conversion bug introduced by recent cleanup.
 5) ade7854-spi - wrong return value.
 
 Some IIO core fixes
 1) Wrong value picked up for event code creation for a modified channel
 2) A null dereference on failure to initialize a buffer after no buffer has
    been in use, when using the available_scan_masks approach.
 3) Sampling not stopped when a device is removed. Effects forced removal
    such as hot unplugging.
 4) Prevent device going away if a chrdev is still open in userspace.
 5) Prevent race on chardev opening and device being freed.
 6) Add a missing iio_buffer_init in the call back buffer.
 
 These last few are the first part of a set from Lars-Peter Clausen who
 has been taking a closer look at our removal paths and buffer handling
 than anyone has for quite some time.
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Merge tag 'iio-fixes-for-3.12a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus

Jonathan writes:

First round of IIO fixes for 3.12

A series of wrong 'struct dev' assumptions in suspend/resume callbacks
following on from this issue being identified in a new driver review.
One to watch out for in future.

A number of driver specific fixes
1) at91 - fix a overflow in clock rate computation
2) dummy - Kconfig dependency issue
3) isl29018 - uninitialized value
4) hmc5843 - measurement conversion bug introduced by recent cleanup.
5) ade7854-spi - wrong return value.

Some IIO core fixes
1) Wrong value picked up for event code creation for a modified channel
2) A null dereference on failure to initialize a buffer after no buffer has
   been in use, when using the available_scan_masks approach.
3) Sampling not stopped when a device is removed. Effects forced removal
   such as hot unplugging.
4) Prevent device going away if a chrdev is still open in userspace.
5) Prevent race on chardev opening and device being freed.
6) Add a missing iio_buffer_init in the call back buffer.

These last few are the first part of a set from Lars-Peter Clausen who
has been taking a closer look at our removal paths and buffer handling
than anyone has for quite some time.

drivers/iio/accel/bma180.c

@@ -620,7 +620,7 @@ static int bma180_remove(struct i2c_client *client)
 #ifdef CONFIG_PM_SLEEP
 static int bma180_suspend(struct device *dev)
 {
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 	struct bma180_data *data = iio_priv(indio_dev);
 	int ret;
 
@@ -633,7 +633,7 @@ static int bma180_suspend(struct device *dev)
 
 static int bma180_resume(struct device *dev)
 {
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 	struct bma180_data *data = iio_priv(indio_dev);
 	int ret;
 

drivers/iio/adc/at91_adc.c

@@ -556,7 +556,7 @@ static const struct iio_info at91_adc_info = {
 
 static int at91_adc_probe(struct platform_device *pdev)
 {
-	unsigned int prsc, mstrclk, ticks, adc_clk, shtim;
+	unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
 	int ret;
 	struct iio_dev *idev;
 	struct at91_adc_state *st;
@@ -649,6 +649,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 	 */
 	mstrclk = clk_get_rate(st->clk);
 	adc_clk = clk_get_rate(st->adc_clk);
+	adc_clk_khz = adc_clk / 1000;
 	prsc = (mstrclk / (2 * adc_clk)) - 1;
 
 	if (!st->startup_time) {
@@ -662,15 +663,15 @@ static int at91_adc_probe(struct platform_device *pdev)
 	 * defined in the electrical characteristics of the board, divided by 8.
 	 * The formula thus is : Startup Time = (ticks + 1) * 8 / ADC Clock
 	 */
-	ticks = round_up((st->startup_time * adc_clk /
-			  1000000) - 1, 8) / 8;
+	ticks = round_up((st->startup_time * adc_clk_khz /
+			  1000) - 1, 8) / 8;
 	/*
 	 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
 	 * the best converted final value between two channels selection
 	 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
 	 */
-	shtim = round_up((st->sample_hold_time * adc_clk /
-			  1000000) - 1, 1);
+	shtim = round_up((st->sample_hold_time * adc_clk_khz /
+			  1000) - 1, 1);
 
 	reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
 	reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;

drivers/iio/buffer_cb.c

@@ -41,6 +41,8 @@ struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
 		goto error_ret;
 	}
 
+	iio_buffer_init(&cb_buff->buffer);
+
 	cb_buff->private = private;
 	cb_buff->cb = cb;
 	cb_buff->buffer.access = &iio_cb_access;

drivers/iio/dac/mcp4725.c

@@ -37,21 +37,21 @@ struct mcp4725_data {
 
 static int mcp4725_suspend(struct device *dev)
 {
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct mcp4725_data *data = iio_priv(indio_dev);
+	struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
+		to_i2c_client(dev)));
 	u8 outbuf[2];
 
 	outbuf[0] = (data->powerdown_mode + 1) << 4;
 	outbuf[1] = 0;
 	data->powerdown = true;
 
-	return i2c_master_send(to_i2c_client(dev), outbuf, 2);
+	return i2c_master_send(data->client, outbuf, 2);
 }
 
 static int mcp4725_resume(struct device *dev)
 {
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct mcp4725_data *data = iio_priv(indio_dev);
+	struct mcp4725_data *data = iio_priv(i2c_get_clientdata(
+		to_i2c_client(dev)));
 	u8 outbuf[2];
 
 	/* restore previous DAC value */
@@ -59,7 +59,7 @@ static int mcp4725_resume(struct device *dev)
 	outbuf[1] = data->dac_value & 0xff;
 	data->powerdown = false;
 
-	return i2c_master_send(to_i2c_client(dev), outbuf, 2);
+	return i2c_master_send(data->client, outbuf, 2);
 }
 
 #ifdef CONFIG_PM_SLEEP

drivers/iio/iio_core.h

@@ -49,11 +49,15 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
 #define iio_buffer_poll_addr (&iio_buffer_poll)
 #define iio_buffer_read_first_n_outer_addr (&iio_buffer_read_first_n_outer)
 
+void iio_disable_all_buffers(struct iio_dev *indio_dev);
+
 #else
 
 #define iio_buffer_poll_addr NULL
 #define iio_buffer_read_first_n_outer_addr NULL
 
+static inline void iio_disable_all_buffers(struct iio_dev *indio_dev) {}
+
 #endif
 
 int iio_device_register_eventset(struct iio_dev *indio_dev);

drivers/iio/industrialio-buffer.c

@@ -460,6 +460,25 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask,
 	return bytes;
 }
 
+void iio_disable_all_buffers(struct iio_dev *indio_dev)
+{
+	struct iio_buffer *buffer, *_buffer;
+
+	if (list_empty(&indio_dev->buffer_list))
+		return;
+
+	if (indio_dev->setup_ops->predisable)
+		indio_dev->setup_ops->predisable(indio_dev);
+
+	list_for_each_entry_safe(buffer, _buffer,
+			&indio_dev->buffer_list, buffer_list)
+		list_del_init(&buffer->buffer_list);
+
+	indio_dev->currentmode = INDIO_DIRECT_MODE;
+	if (indio_dev->setup_ops->postdisable)
+		indio_dev->setup_ops->postdisable(indio_dev);
+}
+
 int iio_update_buffers(struct iio_dev *indio_dev,
 		       struct iio_buffer *insert_buffer,
 		       struct iio_buffer *remove_buffer)
@@ -528,8 +547,15 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 			 * Note can only occur when adding a buffer.
 			 */
 			list_del(&insert_buffer->buffer_list);
-			indio_dev->active_scan_mask = old_mask;
-			success = -EINVAL;
+			if (old_mask) {
+				indio_dev->active_scan_mask = old_mask;
+				success = -EINVAL;
+			}
+			else {
+				kfree(compound_mask);
+				ret = -EINVAL;
+				goto error_ret;
+			}
 		}
 	} else {
 		indio_dev->active_scan_mask = compound_mask;

drivers/iio/industrialio-core.c

@@ -848,8 +848,6 @@ static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 static void iio_dev_release(struct device *device)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(device);
-	if (indio_dev->chrdev.dev)
-		cdev_del(&indio_dev->chrdev);
 	if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 		iio_device_unregister_trigger_consumer(indio_dev);
 	iio_device_unregister_eventset(indio_dev);
@@ -970,6 +968,8 @@ static int iio_chrdev_open(struct inode *inode, struct file *filp)
 	if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
 		return -EBUSY;
 
+	iio_device_get(indio_dev);
+
 	filp->private_data = indio_dev;
 
 	return 0;
@@ -983,6 +983,8 @@ static int iio_chrdev_release(struct inode *inode, struct file *filp)
 	struct iio_dev *indio_dev = container_of(inode->i_cdev,
 						struct iio_dev, chrdev);
 	clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
+	iio_device_put(indio_dev);
+
 	return 0;
 }
 
@@ -1052,18 +1054,20 @@ int iio_device_register(struct iio_dev *indio_dev)
 		indio_dev->setup_ops == NULL)
 		indio_dev->setup_ops = &noop_ring_setup_ops;
 
-	ret = device_add(&indio_dev->dev);
-	if (ret < 0)
-		goto error_unreg_eventset;
 	cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
 	indio_dev->chrdev.owner = indio_dev->info->driver_module;
+	indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
 	ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
 	if (ret < 0)
-		goto error_del_device;
-	return 0;
+		goto error_unreg_eventset;
 
-error_del_device:
-	device_del(&indio_dev->dev);
+	ret = device_add(&indio_dev->dev);
+	if (ret < 0)
+		goto error_cdev_del;
+
+	return 0;
+error_cdev_del:
+	cdev_del(&indio_dev->chrdev);
 error_unreg_eventset:
 	iio_device_unregister_eventset(indio_dev);
 error_free_sysfs:
@@ -1078,9 +1082,16 @@ EXPORT_SYMBOL(iio_device_register);
 void iio_device_unregister(struct iio_dev *indio_dev)
 {
 	mutex_lock(&indio_dev->info_exist_lock);
+
+	device_del(&indio_dev->dev);
+
+	if (indio_dev->chrdev.dev)
+		cdev_del(&indio_dev->chrdev);
+
+	iio_disable_all_buffers(indio_dev);
+
 	indio_dev->info = NULL;
 	mutex_unlock(&indio_dev->info_exist_lock);
-	device_del(&indio_dev->dev);
 }
 EXPORT_SYMBOL(iio_device_unregister);
 subsys_initcall(iio_init);

drivers/iio/industrialio-event.c

@@ -72,7 +72,8 @@ EXPORT_SYMBOL(iio_push_event);
 static unsigned int iio_event_poll(struct file *filep,
 			     struct poll_table_struct *wait)
 {
-	struct iio_event_interface *ev_int = filep->private_data;
+	struct iio_dev *indio_dev = filep->private_data;
+	struct iio_event_interface *ev_int = indio_dev->event_interface;
 	unsigned int events = 0;
 
 	poll_wait(filep, &ev_int->wait, wait);
@@ -90,7 +91,8 @@ static ssize_t iio_event_chrdev_read(struct file *filep,
 				     size_t count,
 				     loff_t *f_ps)
 {
-	struct iio_event_interface *ev_int = filep->private_data;
+	struct iio_dev *indio_dev = filep->private_data;
+	struct iio_event_interface *ev_int = indio_dev->event_interface;
 	unsigned int copied;
 	int ret;
 
@@ -121,7 +123,8 @@ error_unlock:
 
 static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
 {
-	struct iio_event_interface *ev_int = filep->private_data;
+	struct iio_dev *indio_dev = filep->private_data;
+	struct iio_event_interface *ev_int = indio_dev->event_interface;
 
 	spin_lock_irq(&ev_int->wait.lock);
 	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
@@ -133,6 +136,8 @@ static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
 	kfifo_reset_out(&ev_int->det_events);
 	spin_unlock_irq(&ev_int->wait.lock);
 
+	iio_device_put(indio_dev);
+
 	return 0;
 }
 
@@ -158,12 +163,15 @@ int iio_event_getfd(struct iio_dev *indio_dev)
 		return -EBUSY;
 	}
 	spin_unlock_irq(&ev_int->wait.lock);
-	fd = anon_inode_getfd("iio:event",
-				&iio_event_chrdev_fileops, ev_int, O_RDONLY);
+	iio_device_get(indio_dev);
+
+	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
+				indio_dev, O_RDONLY);
 	if (fd < 0) {
 		spin_lock_irq(&ev_int->wait.lock);
 		__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
 		spin_unlock_irq(&ev_int->wait.lock);
+		iio_device_put(indio_dev);
 	}
 	return fd;
 }
@@ -276,7 +284,7 @@ static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
 			goto error_ret;
 		}
 		if (chan->modified)
-			mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel,
+			mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel2,
 						  i/IIO_EV_DIR_MAX,
 						  i%IIO_EV_DIR_MAX);
 		else if (chan->differential)

drivers/iio/temperature/tmp006.c

@@ -255,12 +255,14 @@ static int tmp006_remove(struct i2c_client *client)
 #ifdef CONFIG_PM_SLEEP
 static int tmp006_suspend(struct device *dev)
 {
-	return tmp006_powerdown(iio_priv(dev_to_iio_dev(dev)));
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	return tmp006_powerdown(iio_priv(indio_dev));
 }
 
 static int tmp006_resume(struct device *dev)
 {
-	struct tmp006_data *data = iio_priv(dev_to_iio_dev(dev));
+	struct tmp006_data *data = iio_priv(i2c_get_clientdata(
+		to_i2c_client(dev)));
 	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
 		data->config | TMP006_CONFIG_MOD_MASK);
 }

drivers/staging/iio/Kconfig

@@ -37,7 +37,7 @@ config IIO_SIMPLE_DUMMY_EVENTS
 
 config IIO_SIMPLE_DUMMY_BUFFER
        boolean "Buffered capture support"
-       depends on IIO_KFIFO_BUF
+       select IIO_KFIFO_BUF
        help
          Add buffered data capture to the simple dummy driver.
 

drivers/staging/iio/light/isl29018.c

@@ -563,6 +563,7 @@ static int isl29018_probe(struct i2c_client *client,
 	mutex_init(&chip->lock);
 
 	chip->lux_scale = 1;
+	chip->lux_uscale = 0;
 	chip->range = 1000;
 	chip->adc_bit = 16;
 	chip->suspended = false;

drivers/staging/iio/magnetometer/hmc5843.c

@@ -229,7 +229,7 @@ static int hmc5843_read_measurement(struct iio_dev *indio_dev,
 	if (result < 0)
 		return -EINVAL;
 
-	*val = result;
+	*val = sign_extend32(result, 15);
 	return IIO_VAL_INT;
 }
 

drivers/staging/iio/meter/ade7854-spi.c

@@ -299,7 +299,7 @@ static int ade7854_spi_probe(struct spi_device *spi)
 	if (ret)
 		iio_device_free(indio_dev);
 
-	return 0;
+	return ret;
 }
 
 static int ade7854_spi_remove(struct spi_device *spi)