+/*
+ * Conversions
+ * For local temperatures and limits, critical limits and the hysteresis
+ * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
+ * For remote temperatures and limits, it uses signed 11-bit values with
+ * LSB = 0.125 degree Celsius, left-justified in 16-bit registers. Some
+ * Maxim chips use unsigned values.
+ */
+
+static inline int temp_from_s8(s8 val)
+{
+ return val * 1000;
+}
+
+static inline int temp_from_u8(u8 val)
+{
+ return val * 1000;
+}
+
+static inline int temp_from_s16(s16 val)
+{
+ return val / 32 * 125;
+}
+
+static inline int temp_from_u16(u16 val)
+{
+ return val / 32 * 125;
+}
+
+static s8 temp_to_s8(long val)
+{
+ if (val <= -128000)
+ return -128;
+ if (val >= 127000)
+ return 127;
+ if (val < 0)
+ return (val - 500) / 1000;
+ return (val + 500) / 1000;
+}
+
+static u8 temp_to_u8(long val)
+{
+ if (val <= 0)
+ return 0;
+ if (val >= 255000)
+ return 255;
+ return (val + 500) / 1000;
+}
+
+static s16 temp_to_s16(long val)
+{
+ if (val <= -128000)
+ return 0x8000;
+ if (val >= 127875)
+ return 0x7FE0;
+ if (val < 0)
+ return (val - 62) / 125 * 32;
+ return (val + 62) / 125 * 32;
+}
+
+static u8 hyst_to_reg(long val)
+{
+ if (val <= 0)
+ return 0;
+ if (val >= 30500)
+ return 31;
+ return (val + 500) / 1000;
+}
+
+/*
+ * ADT7461 in compatibility mode is almost identical to LM90 except that
+ * attempts to write values that are outside the range 0 < temp < 127 are
+ * treated as the boundary value.
+ *
+ * ADT7461 in "extended mode" operation uses unsigned integers offset by
+ * 64 (e.g., 0 -> -64 degC). The range is restricted to -64..191 degC.
+ */
+static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
+{
+ if (data->flags & LM90_FLAG_ADT7461_EXT)
+ return (val - 64) * 1000;
+ else
+ return temp_from_s8(val);
+}
+
+static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
+{
+ if (data->flags & LM90_FLAG_ADT7461_EXT)
+ return (val - 0x4000) / 64 * 250;
+ else
+ return temp_from_s16(val);
+}
+
+static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
+{
+ if (data->flags & LM90_FLAG_ADT7461_EXT) {
+ if (val <= -64000)
+ return 0;
+ if (val >= 191000)
+ return 0xFF;
+ return (val + 500 + 64000) / 1000;
+ } else {
+ if (val <= 0)
+ return 0;
+ if (val >= 127000)
+ return 127;
+ return (val + 500) / 1000;
+ }
+}
+
+static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
+{
+ if (data->flags & LM90_FLAG_ADT7461_EXT) {
+ if (val <= -64000)
+ return 0;
+ if (val >= 191750)
+ return 0xFFC0;
+ return (val + 64000 + 125) / 250 * 64;
+ } else {
+ if (val <= 0)
+ return 0;
+ if (val >= 127750)
+ return 0x7FC0;
+ return (val + 125) / 250 * 64;
+ }
+}
+