[PATCH v2 10/16] hwmon: (mr75203) add VM pre-scalar support

Eliav Farber
2022-08-17T05:44:53Z

Add pre-scalar support to normalzie the voltage output results for
channels the use pre-scalar units to get the measurement to be within
the range that the sensor supports.
The pre-scalar value is used if it exists in device-tree, otherwise
default value of 1 is used.

Signed-off-by: Eliav Farber <farbere@amazon.com>
---
drivers/hwmon/mr75203.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
index 2e6139c09efc..24a00339cfd8 100644
--- a/drivers/hwmon/mr75203.c
+++ b/drivers/hwmon/mr75203.c
@@ -112,8 +112,12 @@
struct voltage_device {
u8 vm_map;
u8 ch_map;
+ u32 pre_scaler;
};

+#define PRE_SCALR_PROPERTY_NAME 32
+#define PRE_SCALR_DEFAULT_VAL 1
+
struct pvt_device {
struct regmap *c_map;
struct regmap *t_map;
@@ -215,7 +219,9 @@ static int pvt_read_in(struct device *dev, u32 attr, int channel, long *val)

n &= SAMPLE_DATA_MSK;
/* Convert the N bitstream count into voltage */
- *val = (PVT_N_CONST * n - PVT_R_CONST) >> PVT_CONV_BITS;
+ *val = pvt->vd[channel].pre_scaler;
+ *val *= (PVT_N_CONST * n - PVT_R_CONST);
+ *val >>= PVT_CONV_BITS;

return 0;
default:
@@ -527,6 +533,7 @@ static int pvt_reset_control_deassert(struct device *dev, struct pvt_device *pvt
static int mr75203_probe(struct platform_device *pdev)
{
const struct hwmon_channel_info **pvt_info;
+ const struct device_node *np = pdev->dev.of_node;
u32 ts_num, vm_num, pd_num, ch_num, val, index, i, j, k;
struct device *dev = &pdev->dev;
u32 *temp_config, *in_config;
@@ -552,7 +559,7 @@ static int mr75203_probe(struct platform_device *pdev)
return ret;
}

- if (of_property_read_bool(dev->of_node, "reset-control-skip")) {
+ if (of_property_read_bool(np, "reset-control-skip")) {
dev_info(dev, "skipping reset-control\n");
} else {
pvt->rst = devm_reset_control_get_exclusive(dev, NULL);
@@ -615,6 +622,8 @@ static int mr75203_probe(struct platform_device *pdev)
if (vm_num) {
u8 vm_idx[VM_NUM_MAX];
u8 vm_active_ch[VM_NUM_MAX];
+ char prop_name[PRE_SCALR_PROPERTY_NAME] = {0};
+ u32 pre_scaler;

ret = pvt_get_regmap(pdev, "vm", pvt);
if (ret)
@@ -686,6 +695,21 @@ static int mr75203_probe(struct platform_device *pdev)
k++;
}

+ /*
+ * Incase vm-pre-scalar-ch# property is not defined, we assume
+ * default pre-scaler of 1.
+ */
+ for (i = 0; i < pvt->vm_ch_total; i++) {
+ snprintf(prop_name, sizeof(prop_name),
+ "vm-pre-scalar-ch%u", i);
+
+ ret = of_property_read_u32(np, prop_name, &pre_scaler);
+ if (ret)
+ pvt->vd[i].pre_scaler = PRE_SCALR_DEFAULT_VAL;
+ else
+ pvt->vd[i].pre_scaler = pre_scaler;
+ }
+
in_config = devm_kcalloc(dev, pvt->vm_ch_total + 1,
sizeof(*in_config), GFP_KERNEL);
if (!in_config)
--
2.37.1