staging:iio:ad7291: Simplify threshold register lookup

The AD7291 register map is nicely uniform and we can easily compute the
threshold register address for a certain channel using simple math instead of
using a look-up table.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/adc/ad7291.c b/drivers/staging/iio/adc/ad7291.c
index 5bb1963..bf8d689 100644 (file)
--- a/drivers/staging/iio/adc/ad7291.c
+++ b/drivers/staging/iio/adc/ad7291.c
@@ -39,33 +39,9 @@
 #define AD7291_VOLTAGE                 0x01
 #define AD7291_T_SENSE                 0x02
 #define AD7291_T_AVERAGE               0x03
-#define AD7291_CH0_DATA_HIGH           0x04
-#define AD7291_CH0_DATA_LOW            0x05
-#define AD7291_CH0_HYST                        0x06
-#define AD7291_CH1_DATA_HIGH           0x07
-#define AD7291_CH1_DATA_LOW            0x08
-#define AD7291_CH1_HYST                        0x09
-#define AD7291_CH2_DATA_HIGH           0x0A
-#define AD7291_CH2_DATA_LOW            0x0B
-#define AD7291_CH2_HYST                        0x0C
-#define AD7291_CH3_DATA_HIGH           0x0D
-#define AD7291_CH3_DATA_LOW            0x0E
-#define AD7291_CH3_HYST                        0x0F
-#define AD7291_CH4_DATA_HIGH           0x10
-#define AD7291_CH4_DATA_LOW            0x11
-#define AD7291_CH4_HYST                        0x12
-#define AD7291_CH5_DATA_HIGH           0x13
-#define AD7291_CH5_DATA_LOW            0x14
-#define AD7291_CH5_HYST                        0x15
-#define AD7291_CH6_DATA_HIGH           0x16
-#define AD7291_CH6_DATA_LOW            0x17
-#define AD7291_CH6_HYST                        0x18
-#define AD7291_CH7_DATA_HIGH           0x19
-#define AD7291_CH7_DATA_LOW            0x1A
-#define AD7291_CH7_HYST                        0x2B
-#define AD7291_T_SENSE_HIGH            0x1C
-#define AD7291_T_SENSE_LOW             0x1D
-#define AD7291_T_SENSE_HYST            0x1E
+#define AD7291_DATA_HIGH(x)            ((x) * 3 + 0x4)
+#define AD7291_DATA_LOW(x)             ((x) * 3 + 0x5)
+#define AD7291_HYST(x)                 ((x) * 3 + 0x6)
 #define AD7291_VOLTAGE_ALERT_STATUS    0x1F
 #define AD7291_T_ALERT_STATUS          0x20
 
@@ -232,31 +208,31 @@ static inline ssize_t ad7291_set_hyst(struct device *dev,
 static IIO_DEVICE_ATTR(in_temp0_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
                       ad7291_show_hyst, ad7291_set_hyst,
-                      AD7291_T_SENSE_HYST);
+                      AD7291_HYST(8));
 static IIO_DEVICE_ATTR(in_voltage0_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH0_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(0));
 static IIO_DEVICE_ATTR(in_voltage1_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH1_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(1));
 static IIO_DEVICE_ATTR(in_voltage2_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH2_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(2));
 static IIO_DEVICE_ATTR(in_voltage3_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH3_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(3));
 static IIO_DEVICE_ATTR(in_voltage4_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH4_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(4));
 static IIO_DEVICE_ATTR(in_voltage5_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH5_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(5));
 static IIO_DEVICE_ATTR(in_voltage6_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH6_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(6));
 static IIO_DEVICE_ATTR(in_voltage7_thresh_both_hyst_raw,
                       S_IRUGO | S_IWUSR,
-                      ad7291_show_hyst, ad7291_set_hyst, AD7291_CH7_HYST);
+                      ad7291_show_hyst, ad7291_set_hyst, AD7291_HYST(7));
 
 static struct attribute *ad7291_event_attributes[] = {
        &iio_dev_attr_in_temp0_thresh_both_hyst_raw.dev_attr.attr,
@@ -271,52 +247,46 @@ static struct attribute *ad7291_event_attributes[] = {
        NULL,
 };
 
-/* high / low */
-static u8 ad7291_limit_regs[9][2] = {
-       { AD7291_CH0_DATA_HIGH, AD7291_CH0_DATA_LOW },
-       { AD7291_CH1_DATA_HIGH, AD7291_CH1_DATA_LOW },
-       { AD7291_CH2_DATA_HIGH, AD7291_CH2_DATA_LOW },
-       { AD7291_CH3_DATA_HIGH, AD7291_CH3_DATA_LOW }, /* FIXME: ? */
-       { AD7291_CH4_DATA_HIGH, AD7291_CH4_DATA_LOW },
-       { AD7291_CH5_DATA_HIGH, AD7291_CH5_DATA_LOW },
-       { AD7291_CH6_DATA_HIGH, AD7291_CH6_DATA_LOW },
-       { AD7291_CH7_DATA_HIGH, AD7291_CH7_DATA_LOW },
-       /* temp */
-       { AD7291_T_SENSE_HIGH, AD7291_T_SENSE_LOW },
-};
+static unsigned int ad7291_threshold_reg(u64 event_code)
+{
+       unsigned int offset;
+
+       switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) {
+       case IIO_VOLTAGE:
+               offset = IIO_EVENT_CODE_EXTRACT_CHAN(event_code);
+               break;
+       case IIO_TEMP:
+               offset = 8;
+               break;
+       default:
+           return 0;
+       }
+
+       if (IIO_EVENT_CODE_EXTRACT_DIR(event_code) == IIO_EV_DIR_FALLING)
+               return AD7291_DATA_LOW(offset);
+       else
+               return AD7291_DATA_HIGH(offset);
+}
 
 static int ad7291_read_event_value(struct iio_dev *indio_dev,
                                   u64 event_code,
                                   int *val)
 {
        struct ad7291_chip_info *chip = iio_priv(indio_dev);
-
        int ret;
-       u8 reg;
        u16 uval;
        s16 signval;
 
+       ret = ad7291_i2c_read(chip, ad7291_threshold_reg(event_code), &uval);
+       if (ret < 0)
+               return ret;
+
        switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) {
        case IIO_VOLTAGE:
-               reg = ad7291_limit_regs[IIO_EVENT_CODE_EXTRACT_CHAN(event_code)]
-                       [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) ==
-                          IIO_EV_DIR_RISING)];
-
-               ret = ad7291_i2c_read(chip, reg, &uval);
-               if (ret < 0)
-                       return ret;
                *val = uval & AD7291_VALUE_MASK;
                return 0;
-
        case IIO_TEMP:
-               reg = ad7291_limit_regs[8]
-                       [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) ==
-                          IIO_EV_DIR_RISING)];
-
-               ret = ad7291_i2c_read(chip, reg, &signval);
-               if (ret < 0)
-                       return ret;
-               signval = (s16)((signval & AD7291_VALUE_MASK) << 4) >> 4;
+               signval = (s16)((uval & AD7291_VALUE_MASK) << 4) >> 4;
                *val = signval;
                return 0;
        default:
@@ -329,28 +299,21 @@ static int ad7291_write_event_value(struct iio_dev *indio_dev,
                                    int val)
 {
        struct ad7291_chip_info *chip = iio_priv(indio_dev);
-       u8 reg;
-       s16 signval;
 
        switch (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event_code)) {
        case IIO_VOLTAGE:
                if (val > AD7291_VALUE_MASK || val < 0)
                        return -EINVAL;
-               reg = ad7291_limit_regs[IIO_EVENT_CODE_EXTRACT_CHAN(event_code)]
-                       [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) ==
-                          IIO_EV_DIR_RISING)];
-               return ad7291_i2c_write(chip, reg, val);
+               break;
        case IIO_TEMP:
                if (val > 2047 || val < -2048)
                        return -EINVAL;
-               reg = ad7291_limit_regs[8]
-                       [!(IIO_EVENT_CODE_EXTRACT_DIR(event_code) ==
-                          IIO_EV_DIR_RISING)];
-               signval = val;
-               return ad7291_i2c_write(chip, reg, *(u16 *)&signval);
+               break;
        default:
                return -EINVAL;
-       };
+       }
+
+       return ad7291_i2c_write(chip, ad7291_threshold_reg(event_code), val);
 }
 
 static int ad7291_read_event_config(struct iio_dev *indio_dev,