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.

13 files changed, 91 insertions, 36 deletions

diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
index 12e32e6b4103..81e3dc260993 100644
--- a/drivers/iio/accel/bma180.c
+++ b/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;
 
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 84be63bdf038..0f16b553e063 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/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;
diff --git a/drivers/iio/buffer_cb.c b/drivers/iio/buffer_cb.c
index 9d19ba74f22b..415f3c6efd72 100644
--- a/drivers/iio/buffer_cb.c
+++ b/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;
diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index 1f4a48e6a82c..1397b6e0e414 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/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
diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h
index 05c1b74502a3..9b32253b824b 100644
--- a/drivers/iio/iio_core.h
+++ b/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);
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index e73033f3839a..2710f7245c3b 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/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)