The current equation used in code is aligned to series 5:
T = G + H * (n / cal5 - 0.5) + J * F
Where:
G = 60, H = 200, cal5 = 4094, J = -0.1, F = frequency clock in MHz
Series 6 has a slightly different equation:
T = G + H * (n / cal5 - 0.5)
and a different set of coefficients:
G = 57.4, H = 249.4, cal5 = 4096
This change supports equation and coefficients for both series.
(for series 6, J is set to 0).
The series is determined according to “moortec,ts-series” property in
the device tree.
If absent, series 5 is assumed to be the default.
Signed-off-by: Eliav Farber <farbere@xxxxxxxxxx>
---
V4 -> V3:
- Replace of_property_read_u32() with device_property_read_u32().
- Use switch-case instead of if-else.
V3 -> V2:
- New patch to support temperature sensor series 6 instead of having to
set all 4 coefficients.
drivers/hwmon/mr75203.c | 66 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 62 insertions(+), 4 deletions(-)
diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
index f98fb0f3d2fd..ba5abd4065b3 100644
--- a/drivers/hwmon/mr75203.c
+++ b/drivers/hwmon/mr75203.c
@@ -115,6 +115,15 @@
#define PVT_SERIES5_J_CONST -100
#define PVT_SERIES5_CAL5_CONST 4094
+/* Temperature coefficients for series 6 */
+#define PVT_SERIES6_H_CONST 249400
+#define PVT_SERIES6_G_CONST 57400
+#define PVT_SERIES6_J_CONST 0
+#define PVT_SERIES6_CAL5_CONST 4096
+
+#define TEMPERATURE_SENSOR_SERIES_5 5
+#define TEMPERATURE_SENSOR_SERIES_6 6
+
#define PRE_SCALER_X1 1
#define PRE_SCALER_X2 2
@@ -147,6 +156,13 @@ struct voltage_channels {
u8 max;
};
+struct temp_coeff {
+ u32 h;
+ u32 g;
+ u32 cal5;
+ s32 j;
+};
+
struct pvt_device {
struct regmap *c_map;
struct regmap *t_map;
@@ -156,6 +172,7 @@ struct pvt_device {
struct reset_control *rst;
struct voltage_device *vd;
struct voltage_channels vm_channels;
+ struct temp_coeff ts_coeff;
u32 t_num;
u32 p_num;
u32 v_num;
@@ -186,10 +203,12 @@ static long pvt_calc_temp(struct pvt_device *pvt, u32 nbs)
* Convert the register value to degrees centigrade temperature:
* T = G + H * (n / cal5 - 0.5) + J * F
*/
- s64 tmp = PVT_SERIES5_G_CONST +
- PVT_SERIES5_H_CONST * (s64)nbs / PVT_SERIES5_CAL5_CONST -
- PVT_SERIES5_H_CONST / 2 +
- PVT_SERIES5_J_CONST * (s64)pvt->ip_freq / HZ_PER_MHZ;
+ struct temp_coeff *ts_coeff = &pvt->ts_coeff;
+
+ s64 tmp = ts_coeff->g +
+ ts_coeff->h * (s64)nbs / ts_coeff->cal5 -
+ ts_coeff->h / 2 +
+ ts_coeff->j * (s64)pvt->ip_freq / HZ_PER_MHZ;
return clamp_val(tmp, PVT_TEMP_MIN_mC, PVT_TEMP_MAX_mC);
}
@@ -658,6 +677,41 @@ static int pvt_get_pre_scaler(struct device *dev, struct pvt_device *pvt)
return ret;
}
+static int pvt_set_temp_coeff(struct device *dev, struct pvt_device *pvt)
+{
+ struct temp_coeff *ts_coeff = &pvt->ts_coeff;
+ u32 series;
+ int ret;
+
+ /* Incase ts-series property is not defined, use default 5. */
+ ret = device_property_read_u32(dev, "moortec,ts-series", &series);
+ if (ret)
+ series = TEMPERATURE_SENSOR_SERIES_5;
+
+ switch (series) {
+ case TEMPERATURE_SENSOR_SERIES_5:
+ ts_coeff->h = PVT_SERIES5_H_CONST;
+ ts_coeff->g = PVT_SERIES5_G_CONST;
+ ts_coeff->j = PVT_SERIES5_J_CONST;
+ ts_coeff->cal5 = PVT_SERIES5_CAL5_CONST;
+ break;
+ case TEMPERATURE_SENSOR_SERIES_6:
+ ts_coeff->h = PVT_SERIES6_H_CONST;
+ ts_coeff->g = PVT_SERIES6_G_CONST;
+ ts_coeff->j = PVT_SERIES6_J_CONST;
+ ts_coeff->cal5 = PVT_SERIES6_CAL5_CONST;
+ break;
+ default:
+ dev_err(dev, "invalid temperature sensor series (%u)\n",
+ series);
+ return -EINVAL;
+ }
+
+ dev_dbg(dev, "temperature sensor series = %u\n", series);
+
+ return 0;
+}
+
static int mr75203_probe(struct platform_device *pdev)
{
u32 ts_num, vm_num, pd_num, ch_num, val, index, i;
@@ -728,6 +782,10 @@ static int mr75203_probe(struct platform_device *pdev)
if (ret)
return ret;
+ ret = pvt_set_temp_coeff(dev, pvt);
+ if (ret)
+ return ret;
+
temp_config = devm_kcalloc(dev, ts_num + 1,
sizeof(*temp_config), GFP_KERNEL);
if (!temp_config)
--
2.37.1
