Add mr76006 pre-scaler support to normalize the voltage output result for
channels that use pre-scaler units to get the measurement to be within
the range that the sensor supports.
For channels that are listed in the device-tree to have a pre-scaler, the
voltage result is multiplied by a factor of 2, to represent to the user
the actual voltage source which is measured.
Signed-off-by: Eliav Farber <[email protected]>
---
V3 -> V2:
- Modify code according to new property format.
drivers/hwmon/mr75203.c | 64 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 62 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
index 6925e8490587..1cd5ff6eacce 100644
--- a/drivers/hwmon/mr75203.c
+++ b/drivers/hwmon/mr75203.c
@@ -13,10 +13,12 @@
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
+#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/reset.h>
+#include <linux/slab.h>
/* PVT Common register */
#define PVT_IP_CONFIG 0x04
@@ -108,9 +110,13 @@
#define PVT_N_CONST 90
#define PVT_R_CONST 245805
+#define PRE_SCALER_X1 1
+#define PRE_SCALER_X2 2
+
struct voltage_device {
u32 vm_map; /* Map channel number to VM index */
u32 ch_map; /* Map channel number to channel index */
+ u32 pre_scaler;
};
struct voltage_channels {
@@ -192,7 +198,7 @@ static int pvt_read_in(struct device *dev, u32 attr, int channel, long *val)
{
struct pvt_device *pvt = dev_get_drvdata(dev);
struct regmap *v_map = pvt->v_map;
- u32 n, stat;
+ u32 n, stat, pre_scaler;
u8 vm_idx, ch_idx;
int ret;
@@ -217,7 +223,9 @@ 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;
+ pre_scaler = pvt->vd[channel].pre_scaler;
+ *val = pre_scaler * (PVT_N_CONST * n - PVT_R_CONST) >>
+ PVT_CONV_BITS;
return 0;
default:
@@ -582,6 +590,54 @@ static int pvt_get_active_channel(struct device *dev, struct pvt_device *pvt,
return 0;
}
+static int pvt_get_pre_scaler(struct device *dev, struct pvt_device *pvt)
+{
+ const struct device_node *np = dev->of_node;
+ u32 total_channels = pvt->vm_channels.total;
+ u32 channel;
+ u8 *pre_scaler_ch_list;
+ int i, ret, num_ch;
+
+ /* Set default pre-scaler value to be 1. */
+ for (i = 0; i < total_channels; i++)
+ pvt->vd[i].pre_scaler = PRE_SCALER_X1;
+
+ /* Get number of channels configured in "moortec,vm-pre-scaler". */
+ num_ch = of_property_count_u8_elems(np, "moortec,vm-pre-scaler");
+ if (num_ch <= 0)
+ return 0;
+
+ pre_scaler_ch_list = kcalloc(total_channels,
+ sizeof(*pre_scaler_ch_list), GFP_KERNEL);
+ if (!pre_scaler_ch_list)
+ return -ENOMEM;
+
+ /* Get list of all channels that have pre-scaler of 2. */
+ ret = device_property_read_u8_array(dev, "moortec,vm-pre-scaler",
+ pre_scaler_ch_list, num_ch);
+ if (ret)
+ goto out;
+
+ for (i = 0; i < num_ch; i++) {
+ channel = pre_scaler_ch_list[i];
+
+ if (channel >= total_channels) {
+ dev_err(dev,
+ "invalid channel (%u) in pre-scaler list\n",
+ channel);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ pvt->vd[channel].pre_scaler = PRE_SCALER_X2;
+ }
+
+out:
+ kfree(pre_scaler_ch_list);
+
+ return ret;
+}
+
static int mr75203_probe(struct platform_device *pdev)
{
const struct hwmon_channel_info **pvt_info;
@@ -697,6 +753,10 @@ static int mr75203_probe(struct platform_device *pdev)
if (ret)
return ret;
+ ret = pvt_get_pre_scaler(dev, pvt);
+ if (ret)
+ return ret;
+
in_config = devm_kcalloc(dev, pvt->vm_channels.total + 1,
sizeof(*in_config), GFP_KERNEL);
if (!in_config)
--
2.37.1
On Tue, Aug 30, 2022 at 07:22:04PM +0000, Eliav Farber wrote:
> Add mr76006 pre-scaler support to normalize the voltage output result for
> channels that use pre-scaler units to get the measurement to be within
> the range that the sensor supports.
>
> For channels that are listed in the device-tree to have a pre-scaler, the
> voltage result is multiplied by a factor of 2, to represent to the user
> the actual voltage source which is measured.
...
> +static int pvt_get_pre_scaler(struct device *dev, struct pvt_device *pvt)
> +{
> + const struct device_node *np = dev->of_node;
> + u32 total_channels = pvt->vm_channels.total;
> + u32 channel;
> + u8 *pre_scaler_ch_list;
> + int i, ret, num_ch;
> +
> + /* Set default pre-scaler value to be 1. */
> + for (i = 0; i < total_channels; i++)
> + pvt->vd[i].pre_scaler = PRE_SCALER_X1;
> +
> + /* Get number of channels configured in "moortec,vm-pre-scaler". */
> + num_ch = of_property_count_u8_elems(np, "moortec,vm-pre-scaler");
of_ ?!
> + if (num_ch <= 0)
> + return 0;
> +
> + pre_scaler_ch_list = kcalloc(total_channels,
> + sizeof(*pre_scaler_ch_list), GFP_KERNEL);
> + if (!pre_scaler_ch_list)
> + return -ENOMEM;
> +
> + /* Get list of all channels that have pre-scaler of 2. */
> + ret = device_property_read_u8_array(dev, "moortec,vm-pre-scaler",
> + pre_scaler_ch_list, num_ch);
> + if (ret)
> + goto out;
> +
> + for (i = 0; i < num_ch; i++) {
> + channel = pre_scaler_ch_list[i];
> +
Unnecessary blank line.
> + if (channel >= total_channels) {
> + dev_err(dev,
> + "invalid channel (%u) in pre-scaler list\n",
> + channel);
> + ret = -EINVAL;
> + goto out;
Wouldn't
break;
suffice? (I understand the point, up to you)
> + }
> +
> + pvt->vd[channel].pre_scaler = PRE_SCALER_X2;
> + }
> +
> +out:
out_free:
> + kfree(pre_scaler_ch_list);
> +
> + return ret;
> +}
--
With Best Regards,
Andy Shevchenko
On 8/31/2022 3:02 PM, Andy Shevchenko wrote:
> On Tue, Aug 30, 2022 at 07:22:04PM +0000, Eliav Farber wrote:
>> +static int pvt_get_pre_scaler(struct device *dev, struct pvt_device
>> *pvt)
>> +{
>> + const struct device_node *np = dev->of_node;
>> + u32 total_channels = pvt->vm_channels.total;
>> + u32 channel;
>> + u8 *pre_scaler_ch_list;
>> + int i, ret, num_ch;
>> +
>> + /* Set default pre-scaler value to be 1. */
>> + for (i = 0; i < total_channels; i++)
>> + pvt->vd[i].pre_scaler = PRE_SCALER_X1;
>> +
>> + /* Get number of channels configured in
>> "moortec,vm-pre-scaler". */
>> + num_ch = of_property_count_u8_elems(np, "moortec,vm-pre-scaler");
>
> of_ ?!
>
Replaced of_property_count_u8_elems() with
device_property_count_u8().
>> + if (num_ch <= 0)
>> + return 0;
>> +
>> + pre_scaler_ch_list = kcalloc(total_channels,
>> + sizeof(*pre_scaler_ch_list),
>> GFP_KERNEL);
>> + if (!pre_scaler_ch_list)
>> + return -ENOMEM;
>> +
>> + /* Get list of all channels that have pre-scaler of 2. */
>> + ret = device_property_read_u8_array(dev, "moortec,vm-pre-scaler",
>> + pre_scaler_ch_list, num_ch);
>> + if (ret)
>> + goto out;
>> +
>> + for (i = 0; i < num_ch; i++) {
>> + channel = pre_scaler_ch_list[i];
>
>> +
>
> Unnecessary blank line.
Blank line removed.
>> + if (channel >= total_channels) {
>> + dev_err(dev,
>> + "invalid channel (%u) in pre-scaler
>> list\n",
>> + channel);
>> + ret = -EINVAL;
>
>> + goto out;
>
> Wouldn't
>
> break;
>
> suffice? (I understand the point, up to you)
I prefer to exit the moment I detect a problem.
For now I can use a break but in the future someone else can add new code
in between that will set ret to 0 and instead of failing driver flow will
continue with incomplete pre-scaler value.
So I prefer keeping it as it.
--
Best regards, Eliav