iio: magnetometer: ak8974: add Alps hscdtd008a

The hscdtd008a is similar to the AK8974:
Only the whoami value and some registers are different.

Signed-off-by: Nick Reitemeyer <nick.reitemeyer@web.de>
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Tested-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c
index 372c80c25dd4f4c5c96f2429cf7972f609e5d112..407f0dd64a7ac4c8248f2141e4291a9716f4c8a1 100644 (file)
--- a/drivers/iio/magnetometer/ak8974.c
+++ b/drivers/iio/magnetometer/ak8974.c
@@ -49,6 +49,7 @@
 #define AK8974_WHOAMI_VALUE_AMI306 0x46
 #define AK8974_WHOAMI_VALUE_AMI305 0x47
 #define AK8974_WHOAMI_VALUE_AK8974 0x48
+#define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49
 
 #define AK8974_DATA_X          0x10
 #define AK8974_DATA_Y          0x12
@@ -140,6 +141,12 @@
 #define AK8974_INT_CTRL_PULSE  BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
 
+/* HSCDTD008A-specific control register */
+#define HSCDTD008A_CTRL4       0x1E
+#define HSCDTD008A_CTRL4_MMD   BIT(7)  /* must be set to 1 */
+#define HSCDTD008A_CTRL4_RANGE BIT(4)  /* 0 = 14-bit output; 1 = 15-bit output */
+#define HSCDTD008A_CTRL4_RESDEF        (HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE)
+
 /* The AMI305 has elaborate FW version and serial number registers */
 #define AMI305_VER             0xE8
 #define AMI305_SN              0xEA
@@ -241,10 +248,17 @@ static int ak8974_reset(struct ak8974 *ak8974)
        ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
        if (ret)
                return ret;
-       ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
-                          AK8974_INT_CTRL_RESDEF);
-       if (ret)
-               return ret;
+       if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) {
+               ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
+                                  AK8974_INT_CTRL_RESDEF);
+               if (ret)
+                       return ret;
+       } else {
+               ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4,
+                                  HSCDTD008A_CTRL4_RESDEF);
+               if (ret)
+                       return ret;
+       }
 
        /* After reset, power off is default state */
        return ak8974_set_power(ak8974, AK8974_PWR_OFF);
@@ -267,6 +281,8 @@ static int ak8974_configure(struct ak8974 *ak8974)
                if (ret)
                        return ret;
        }
+       if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A)
+               return 0;
        ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
        if (ret)
                return ret;
@@ -495,6 +511,10 @@ static int ak8974_detect(struct ak8974 *ak8974)
                name = "ak8974";
                dev_info(&ak8974->i2c->dev, "detected AK8974\n");
                break;
+       case AK8974_WHOAMI_VALUE_HSCDTD008A:
+               name = "hscdtd008a";
+               dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n");
+               break;
        default:
                dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
                        whoami);
@@ -674,18 +694,18 @@ static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
        case AK8974_INT_CTRL:
        case AK8974_INT_THRES:
        case AK8974_INT_THRES + 1:
+               return true;
        case AK8974_PRESET:
        case AK8974_PRESET + 1:
-               return true;
+               return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A;
        case AK8974_OFFSET_X:
        case AK8974_OFFSET_X + 1:
        case AK8974_OFFSET_Y:
        case AK8974_OFFSET_Y + 1:
        case AK8974_OFFSET_Z:
        case AK8974_OFFSET_Z + 1:
-               if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
-                       return true;
-               return false;
+               return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 ||
+                      ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A;
        case AMI305_OFFSET_X:
        case AMI305_OFFSET_X + 1:
        case AMI305_OFFSET_Y:
@@ -931,12 +951,14 @@ static const struct i2c_device_id ak8974_id[] = {
        {"ami305", 0 },
        {"ami306", 0 },
        {"ak8974", 0 },
+       {"hscdtd008a", 0 },
        {}
 };
 MODULE_DEVICE_TABLE(i2c, ak8974_id);
 
 static const struct of_device_id ak8974_of_match[] = {
        { .compatible = "asahi-kasei,ak8974", },
+       { .compatible = "alps,hscdtd008a", },
        {}
 };
 MODULE_DEVICE_TABLE(of, ak8974_of_match);