10 files changed, 166 insertions, 151 deletions

diff --git a/drivers/iio/adc/mcp3422.c b/drivers/iio/adc/mcp3422.c
index 51672256072b..b96c636470ef 100644
--- a/drivers/iio/adc/mcp3422.c
+++ b/drivers/iio/adc/mcp3422.c
@@ -58,20 +58,11 @@
                 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
         }
 
-/* LSB is in nV to eliminate floating point */
-static const u32 rates_to_lsb[] = {1000000, 250000, 62500, 15625};
-
-/*
- *  scales calculated as:
- *  rates_to_lsb[sample_rate] / (1 << pga);
- *  pga is 1 for 0, 2
- */
-
 static const int mcp3422_scales[4][4] = {
-        { 1000000, 250000, 62500, 15625 },
-        { 500000 , 125000, 31250, 7812 },
-        { 250000 , 62500 , 15625, 3906 },
-        { 125000 , 31250 , 7812 , 1953 } };
+        { 1000000, 500000, 250000, 125000 },
+        { 250000 , 125000, 62500 , 31250  },
+        { 62500  , 31250 , 15625 , 7812   },
+        { 15625  , 7812  , 3906  , 1953   } };
 
 /* Constant msleep times for data acquisitions */
 static const int mcp3422_read_times[4] = {
diff --git a/drivers/iio/adc/qcom-spmi-iadc.c b/drivers/iio/adc/qcom-spmi-iadc.c
index b9666f2f5e51..fabd24edc2a1 100644
--- a/drivers/iio/adc/qcom-spmi-iadc.c
+++ b/drivers/iio/adc/qcom-spmi-iadc.c
@@ -296,7 +296,8 @@ static int iadc_do_conversion(struct iadc_chip *iadc, int chan, u16 *data)
         if (iadc->poll_eoc) {
                 ret = iadc_poll_wait_eoc(iadc, wait);
         } else {
-                ret = wait_for_completion_timeout(&iadc->complete, wait);
+                ret = wait_for_completion_timeout(&iadc->complete,
+                        usecs_to_jiffies(wait));
                 if (!ret)
                         ret = -ETIMEDOUT;
                 else
diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
index f57562aa396f..15c73e20272d 100644
--- a/drivers/iio/dac/ad5686.c
+++ b/drivers/iio/dac/ad5686.c
@@ -322,7 +322,7 @@ static int ad5686_probe(struct spi_device *spi)
         st = iio_priv(indio_dev);
         spi_set_drvdata(spi, indio_dev);
 
-        st->reg = devm_regulator_get(&spi->dev, "vcc");
+        st->reg = devm_regulator_get_optional(&spi->dev, "vcc");
         if (!IS_ERR(st->reg)) {
                 ret = regulator_enable(st->reg);
                 if (ret)
diff --git a/drivers/iio/humidity/dht11.c b/drivers/iio/humidity/dht11.c
index 623c145d8a97..7d79a1ac5f5f 100644
--- a/drivers/iio/humidity/dht11.c
+++ b/drivers/iio/humidity/dht11.c
@@ -29,6 +29,7 @@
 #include <linux/wait.h>
 #include <linux/bitops.h>
 #include <linux/completion.h>
+#include <linux/mutex.h>
 #include <linux/delay.h>
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
@@ -39,8 +40,12 @@
 
 #define DHT11_DATA_VALID_TIME   2000000000  /* 2s in ns */
 
-#define DHT11_EDGES_PREAMBLE 4
+#define DHT11_EDGES_PREAMBLE 2
 #define DHT11_BITS_PER_READ 40
+/*
+ * Note that when reading the sensor actually 84 edges are detected, but
+ * since the last edge is not significant, we only store 83:
+ */
 #define DHT11_EDGES_PER_READ (2*DHT11_BITS_PER_READ + DHT11_EDGES_PREAMBLE + 1)
 
 /* Data transmission timing (nano seconds) */
@@ -57,6 +62,7 @@ struct dht11 {
         int                             irq;
 
         struct completion               completion;
+        struct mutex                    lock;
 
         s64                             timestamp;
         int                             temperature;
@@ -88,7 +94,7 @@ static int dht11_decode(struct dht11 *dht11, int offset)
         unsigned char temp_int, temp_dec, hum_int, hum_dec, checksum;
 
         /* Calculate timestamp resolution */
-        for (i = 0; i < dht11->num_edges; ++i) {
+        for (i = 1; i < dht11->num_edges; ++i) {
                 t = dht11->edges[i].ts - dht11->edges[i-1].ts;
                 if (t > 0 && t < timeres)
                         timeres = t;
@@ -138,6 +144,27 @@ static int dht11_decode(struct dht11 *dht11, int offset)
         return 0;
 }
 
+/*
+ * IRQ handler called on GPIO edges
+ */
+static irqreturn_t dht11_handle_irq(int irq, void *data)
+{
+        struct iio_dev *iio = data;
+        struct dht11 *dht11 = iio_priv(iio);
+
+        /* TODO: Consider making the handler safe for IRQ sharing */
+        if (dht11->num_edges < DHT11_EDGES_PER_READ && dht11->num_edges >= 0) {
+                dht11->edges[dht11->num_edges].ts = iio_get_time_ns();
+                dht11->edges[dht11->num_edges++].value =
+                                                gpio_get_value(dht11->gpio);
+
+                if (dht11->num_edges >= DHT11_EDGES_PER_READ)
+                        complete(&dht11->completion);
+        }
+
+        return IRQ_HANDLED;
+}
+
 static int dht11_read_raw(struct iio_dev *iio_dev,
                         const struct iio_chan_spec *chan,
                         int *val, int *val2, long m)
@@ -145,6 +172,7 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
         struct dht11 *dht11 = iio_priv(iio_dev);
         int ret;
 
+        mutex_lock(&dht11->lock);
         if (dht11->timestamp + DHT11_DATA_VALID_TIME < iio_get_time_ns()) {
                 reinit_completion(&dht11->completion);
 
@@ -157,8 +185,17 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
                 if (ret)
                         goto err;
 
+                ret = request_irq(dht11->irq, dht11_handle_irq,
+                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+                                  iio_dev->name, iio_dev);
+                if (ret)
+                        goto err;
+
                 ret = wait_for_completion_killable_timeout(&dht11->completion,
                                                                  HZ);
+
+                free_irq(dht11->irq, iio_dev);
+
                 if (ret == 0 && dht11->num_edges < DHT11_EDGES_PER_READ - 1) {
                         dev_err(&iio_dev->dev,
                                         "Only %d signal edges detected\n",
@@ -185,6 +222,7 @@ static int dht11_read_raw(struct iio_dev *iio_dev,
                 ret = -EINVAL;
 err:
         dht11->num_edges = -1;
+        mutex_unlock(&dht11->lock);
         return ret;
 }