staging:iio:adc:ad7152: Miscellaneous fixes and touch-up

Remove unused define.
Introduce cached SETUP variables.
Wait until calibration finished. (Device returns to idle state)
IIO_CHAN_INFO_CALIBSCALE_SEPARATE use proper scales. (range 1.0 to 1.99999)
i2c_smbus word transactions expect low byte first, therefore swap bytes.
CAPDIFF is bit in SETUP not CFG.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/adc/ad7152.c b/drivers/staging/iio/adc/ad7152.c
index a43cf63a9edcc82cc07ff7cfd988c59c5d755903..6b9d7eae07399a72497104f2594492c56d847c3e 100644 (file)
--- a/drivers/staging/iio/adc/ad7152.c
+++ b/drivers/staging/iio/adc/ad7152.c
@@ -52,6 +52,7 @@
 #define AD7152_SETUP_RANGE_0_5pF       (1 << 6)
 #define AD7152_SETUP_RANGE_1pF         (2 << 6)
 #define AD7152_SETUP_RANGE_4pF         (3 << 6)
+#define AD7152_SETUP_RANGE(x)          ((x) << 6)
 
 /* Config Register Bit Designations (AD7152_REG_CFG) */
 #define AD7152_CONF_CH2EN              (1 << 3)
@@ -66,8 +67,6 @@
 #define AD7152_CAPDAC_DACEN            (1 << 7)
 #define AD7152_CAPDAC_DACP(x)          ((x) & 0x1F)
 
-#define AD7152_MAX_CONV_MODE           6
-
 enum {
        AD7152_DATA,
        AD7152_OFFS,
@@ -85,7 +84,8 @@ struct ad7152_chip_info {
         * Capacitive channel digital filter setup;
         * conversion time/update rate setup per channel
         */
-       u8  filter_rate_setup;
+       u8      filter_rate_setup;
+       u8      setup[2];
 };
 
 static inline ssize_t ad7152_start_calib(struct device *dev,
@@ -98,7 +98,7 @@ static inline ssize_t ad7152_start_calib(struct device *dev,
        struct ad7152_chip_info *chip = iio_priv(dev_info);
        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
        bool doit;
-       int ret;
+       int ret, timeout = 10;
 
        ret = strtobool(buf, &doit);
        if (ret < 0)
@@ -115,8 +115,14 @@ static inline ssize_t ad7152_start_calib(struct device *dev,
        ret = i2c_smbus_write_byte_data(chip->client, AD7152_REG_CFG, regval);
        if (ret < 0)
                return ret;
-       /* Unclear on period this should be set for or whether it flips back
-        * to idle automatically */
+
+       do {
+               mdelay(20);
+               ret = i2c_smbus_read_byte_data(chip->client, AD7152_REG_CFG);
+               if (ret < 0)
+                       return ret;
+       } while ((ret == regval) && timeout--);
+
        return len;
 }
 static ssize_t ad7152_start_offset_calib(struct device *dev,
@@ -124,7 +130,6 @@ static ssize_t ad7152_start_offset_calib(struct device *dev,
                                         const char *buf,
                                         size_t len)
 {
-
        return ad7152_start_calib(dev, attr, buf, len,
                                  AD7152_CONF_MODE_OFFS_CAL);
 }
@@ -222,11 +227,14 @@ static int ad7152_write_raw(struct iio_dev *dev_info,
 
        switch (mask) {
        case (1 << IIO_CHAN_INFO_CALIBSCALE_SEPARATE):
-               if ((val < 0) | (val > 0xFFFF))
+               if (val != 1)
                        return -EINVAL;
+
+               val = (val2 * 1024) / 15625;
+
                ret = i2c_smbus_write_word_data(chip->client,
                                ad7152_addresses[chan->channel][AD7152_GAIN],
-                               val);
+                               swab16(val));
                if (ret < 0)
                        return ret;
 
@@ -237,7 +245,7 @@ static int ad7152_write_raw(struct iio_dev *dev_info,
                        return -EINVAL;
                ret = i2c_smbus_write_word_data(chip->client,
                                ad7152_addresses[chan->channel][AD7152_OFFS],
-                               val);
+                               swab16(val));
                if (ret < 0)
                        return ret;
 
@@ -248,14 +256,13 @@ static int ad7152_write_raw(struct iio_dev *dev_info,
                for (i = 0; i < ARRAY_SIZE(ad7152_scale_table); i++)
                        if (val2 <= ad7152_scale_table[i])
                                break;
-               ret = i2c_smbus_read_byte_data(chip->client,
-                               ad7152_addresses[chan->channel][AD7152_SETUP]);
-               if (ret < 0)
-                       return ret;
-               if ((ret & 0xC0) != i)
-                       ret = i2c_smbus_write_byte_data(chip->client,
+
+               chip->setup[chan->channel] &= ~AD7152_SETUP_RANGE_4pF;
+               chip->setup[chan->channel] |= AD7152_SETUP_RANGE(i);
+
+               ret = i2c_smbus_write_byte_data(chip->client,
                                ad7152_addresses[chan->channel][AD7152_SETUP],
-                               (ret & ~0xC0) | i);
+                               chip->setup[chan->channel]);
                if (ret < 0)
                        return ret;
                else
@@ -275,18 +282,30 @@ static int ad7152_read_raw(struct iio_dev *dev_info,
        switch (mask) {
        case 0:
                /* First set whether in differential mode */
+
+               regval = chip->setup[chan->channel];
+
                if (chan->differential)
-                       regval = AD7152_SETUP_CAPDIFF;
+                       chip->setup[chan->channel] |= AD7152_SETUP_CAPDIFF;
+               else
+                       chip->setup[chan->channel] &= ~AD7152_SETUP_CAPDIFF;
 
+               if (regval != chip->setup[chan->channel]) {
+                       ret = i2c_smbus_write_byte_data(chip->client,
+                               ad7152_addresses[chan->channel][AD7152_SETUP],
+                               chip->setup[chan->channel]);
+                       if (ret < 0)
+                               return ret;
+               }
                /* Make sure the channel is enabled */
-               if (chan->address == 0)
-                       regval |= AD7152_CONF_CH1EN;
+               if (chan->channel == 0)
+                       regval = AD7152_CONF_CH1EN;
                else
-                       regval |= AD7152_CONF_CH2EN;
+                       regval = AD7152_CONF_CH2EN;
+
                /* Trigger a single read */
                regval |= AD7152_CONF_MODE_SINGLE_CONV;
-               ret = i2c_smbus_write_byte_data(chip->client,
-                               ad7152_addresses[chan->channel][AD7152_SETUP],
+               ret = i2c_smbus_write_byte_data(chip->client, AD7152_REG_CFG,
                                regval);
                if (ret < 0)
                        return ret;
@@ -297,24 +316,26 @@ static int ad7152_read_raw(struct iio_dev *dev_info,
                                ad7152_addresses[chan->channel][AD7152_DATA]);
                if (ret < 0)
                        return ret;
-               *val = ret;
+               *val = swab16(ret);
 
                return IIO_VAL_INT;
        case (1 << IIO_CHAN_INFO_CALIBSCALE_SEPARATE):
-               /* FIXME: Hmm. very small. it's 1+ 1/(2^16 *val) */
+
                ret = i2c_smbus_read_word_data(chip->client,
                                ad7152_addresses[chan->channel][AD7152_GAIN]);
                if (ret < 0)
                        return ret;
-               *val = ret;
+               /* 1 + gain_val / 2^16 */
+               *val = 1;
+               *val2 = (15625 * swab16(ret)) / 1024;
 
-               return IIO_VAL_INT;
+               return IIO_VAL_INT_PLUS_MICRO;
        case (1 << IIO_CHAN_INFO_CALIBBIAS_SEPARATE):
                ret = i2c_smbus_read_word_data(chip->client,
                                ad7152_addresses[chan->channel][AD7152_OFFS]);
                if (ret < 0)
                        return ret;
-               *val = ret;
+               *val = swab16(ret);
 
                return IIO_VAL_INT;
        case (1 << IIO_CHAN_INFO_SCALE_SEPARATE):