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path: root/drivers/iio/adc/pac1921.c
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Diffstat (limited to 'drivers/iio/adc/pac1921.c')
-rw-r--r--drivers/iio/adc/pac1921.c160
1 files changed, 122 insertions, 38 deletions
diff --git a/drivers/iio/adc/pac1921.c b/drivers/iio/adc/pac1921.c
index 36e813d9c73f..a0227b57f238 100644
--- a/drivers/iio/adc/pac1921.c
+++ b/drivers/iio/adc/pac1921.c
@@ -7,11 +7,13 @@
#include <linux/unaligned.h>
#include <linux/bitfield.h>
+#include <linux/cleanup.h>
#include <linux/i2c.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
+#include <linux/limits.h>
#include <linux/regmap.h>
#include <linux/units.h>
@@ -67,6 +69,14 @@ enum pac1921_mxsl {
#define PAC1921_DEFAULT_DI_GAIN 0 /* 2^(value): 1x gain (HW default) */
#define PAC1921_DEFAULT_NUM_SAMPLES 0 /* 2^(value): 1 sample (HW default) */
+#define PAC1921_ACPI_GET_uOHMS_VALS 0
+#define PAC1921_ACPI_GET_LABEL 1
+
+/* f7bb9932-86ee-4516-a236-7a7a742e55cb */
+static const guid_t pac1921_guid =
+ GUID_INIT(0xf7bb9932, 0x86ee, 0x4516, 0xa2,
+ 0x36, 0x7a, 0x7a, 0x74, 0x2e, 0x55, 0xcb);
+
/*
* Pre-computed scale factors for BUS voltage
* format: IIO_VAL_INT_PLUS_NANO
@@ -200,7 +210,7 @@ struct pac1921_priv {
struct {
u16 chan[PAC1921_NUM_MEAS_CHANS];
- s64 timestamp __aligned(8);
+ aligned_s64 timestamp;
} scan;
};
@@ -241,7 +251,7 @@ static inline void pac1921_calc_scale(int dividend, int divisor, int *val,
s64 tmp;
tmp = div_s64(dividend * (s64)NANO, divisor);
- *val = (int)div_s64_rem(tmp, NANO, val2);
+ *val = div_s64_rem(tmp, NANO, val2);
}
/*
@@ -260,7 +270,7 @@ static void pac1921_calc_current_scales(struct pac1921_priv *priv)
int max = (PAC1921_MAX_VSENSE_MV * MICRO) >> i;
int vsense_lsb = DIV_ROUND_CLOSEST(max, PAC1921_RES_RESOLUTION);
- pac1921_calc_scale(vsense_lsb, (int)priv->rshunt_uohm,
+ pac1921_calc_scale(vsense_lsb, priv->rshunt_uohm,
&priv->current_scales[i][0],
&priv->current_scales[i][1]);
}
@@ -314,7 +324,7 @@ static int pac1921_check_push_overflow(struct iio_dev *indio_dev, s64 timestamp)
timestamp);
}
- priv->prev_ovf_flags = (u8)flags;
+ priv->prev_ovf_flags = flags;
return 0;
}
@@ -329,8 +339,7 @@ static int pac1921_check_push_overflow(struct iio_dev *indio_dev, s64 timestamp)
static int pac1921_read_res(struct pac1921_priv *priv, unsigned long reg,
u16 *val)
{
- int ret = regmap_bulk_read(priv->regmap, (unsigned int)reg, val,
- sizeof(*val));
+ int ret = regmap_bulk_read(priv->regmap, reg, val, sizeof(*val));
if (ret)
return ret;
@@ -366,7 +375,7 @@ static int pac1921_read_raw(struct iio_dev *indio_dev,
if (ret)
return ret;
- *val = (int)res_val;
+ *val = res_val;
return IIO_VAL_INT;
}
@@ -400,10 +409,10 @@ static int pac1921_read_raw(struct iio_dev *indio_dev,
s64 tmp = curr_scale[0] * (s64)NANO + curr_scale[1];
/* Multiply by max_vbus (V) / dv_gain */
- tmp *= PAC1921_MAX_VBUS_V >> (int)priv->dv_gain;
+ tmp *= PAC1921_MAX_VBUS_V >> priv->dv_gain;
/* Convert back to INT_PLUS_NANO */
- *val = (int)div_s64_rem(tmp, NANO, val2);
+ *val = div_s64_rem(tmp, NANO, val2);
return IIO_VAL_INT_PLUS_NANO;
}
@@ -426,7 +435,7 @@ static int pac1921_read_raw(struct iio_dev *indio_dev,
* 1/(integr_period_usecs/MICRO) = MICRO/integr_period_usecs
*/
*val = MICRO;
- *val2 = (int)priv->integr_period_usecs;
+ *val2 = priv->integr_period_usecs;
return IIO_VAL_FRACTIONAL;
default:
@@ -503,7 +512,7 @@ static int pac1921_lookup_scale(const int (*const scales_tbl)[2], size_t size,
for (unsigned int i = 0; i < size; i++)
if (scales_tbl[i][0] == scale_val &&
scales_tbl[i][1] == scale_val2)
- return (int)i;
+ return i;
return -EINVAL;
}
@@ -553,7 +562,7 @@ static int pac1921_update_gain_from_scale(struct pac1921_priv *priv,
if (ret < 0)
return ret;
- return pac1921_update_gain(priv, &priv->dv_gain, (u8)ret,
+ return pac1921_update_gain(priv, &priv->dv_gain, ret,
PAC1921_GAIN_DV_GAIN_MASK);
case PAC1921_CHAN_VSENSE:
ret = pac1921_lookup_scale(pac1921_vsense_scales,
@@ -562,7 +571,7 @@ static int pac1921_update_gain_from_scale(struct pac1921_priv *priv,
if (ret < 0)
return ret;
- return pac1921_update_gain(priv, &priv->di_gain, (u8)ret,
+ return pac1921_update_gain(priv, &priv->di_gain, ret,
PAC1921_GAIN_DI_GAIN_MASK);
case PAC1921_CHAN_CURRENT:
ret = pac1921_lookup_scale(priv->current_scales,
@@ -571,7 +580,7 @@ static int pac1921_update_gain_from_scale(struct pac1921_priv *priv,
if (ret < 0)
return ret;
- return pac1921_update_gain(priv, &priv->di_gain, (u8)ret,
+ return pac1921_update_gain(priv, &priv->di_gain, ret,
PAC1921_GAIN_DI_GAIN_MASK);
default:
return -EINVAL;
@@ -586,7 +595,7 @@ static int pac1921_lookup_int_num_samples(int num_samples)
{
for (unsigned int i = 0; i < ARRAY_SIZE(pac1921_int_num_samples); i++)
if (pac1921_int_num_samples[i] == num_samples)
- return (int)i;
+ return i;
return -EINVAL;
}
@@ -607,7 +616,7 @@ static int pac1921_update_int_num_samples(struct pac1921_priv *priv,
if (ret < 0)
return ret;
- n_samples = (u8)ret;
+ n_samples = ret;
if (priv->n_samples == n_samples)
return 0;
@@ -663,13 +672,13 @@ static int pac1921_read_label(struct iio_dev *indio_dev,
{
switch (chan->channel) {
case PAC1921_CHAN_VBUS:
- return sprintf(label, "vbus\n");
+ return sysfs_emit(label, "vbus\n");
case PAC1921_CHAN_VSENSE:
- return sprintf(label, "vsense\n");
+ return sysfs_emit(label, "vsense\n");
case PAC1921_CHAN_CURRENT:
- return sprintf(label, "current\n");
+ return sysfs_emit(label, "current\n");
case PAC1921_CHAN_POWER:
- return sprintf(label, "power\n");
+ return sysfs_emit(label, "power\n");
default:
return -EINVAL;
}
@@ -700,7 +709,8 @@ static int pac1921_read_event_config(struct iio_dev *indio_dev,
static int pac1921_write_event_config(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
- enum iio_event_direction dir, int state)
+ enum iio_event_direction dir,
+ bool state)
{
struct pac1921_priv *priv = iio_priv(indio_dev);
u8 ovf_bit;
@@ -770,7 +780,7 @@ static ssize_t pac1921_read_shunt_resistor(struct iio_dev *indio_dev,
guard(mutex)(&priv->lock);
- vals[0] = (int)priv->rshunt_uohm;
+ vals[0] = priv->rshunt_uohm;
vals[1] = MICRO;
return iio_format_value(buf, IIO_VAL_FRACTIONAL, 1, vals);
@@ -782,7 +792,7 @@ static ssize_t pac1921_write_shunt_resistor(struct iio_dev *indio_dev,
const char *buf, size_t len)
{
struct pac1921_priv *priv = iio_priv(indio_dev);
- u64 rshunt_uohm;
+ u32 rshunt_uohm;
int val, val_fract;
int ret;
@@ -793,13 +803,20 @@ static ssize_t pac1921_write_shunt_resistor(struct iio_dev *indio_dev,
if (ret)
return ret;
- rshunt_uohm = (u32)val * MICRO + (u32)val_fract;
- if (rshunt_uohm == 0 || rshunt_uohm > INT_MAX)
+ /*
+ * This check validates the shunt is not zero and does not surpass
+ * INT_MAX. The check is done before calculating in order to avoid
+ * val * MICRO overflowing.
+ */
+ if ((!val && !val_fract) || val > INT_MAX / MICRO ||
+ (val == INT_MAX / MICRO && val_fract > INT_MAX % MICRO))
return -EINVAL;
+ rshunt_uohm = val * MICRO + val_fract;
+
guard(mutex)(&priv->lock);
- priv->rshunt_uohm = (u32)rshunt_uohm;
+ priv->rshunt_uohm = rshunt_uohm;
pac1921_calc_current_scales(priv);
@@ -883,7 +900,7 @@ static ssize_t pac1921_read_scale_avail(struct iio_dev *indio_dev,
static const struct iio_chan_spec_ext_info pac1921_ext_info_voltage[] = {
PAC1921_EXT_INFO_SCALE_AVAIL,
- {}
+ { }
};
static const struct iio_chan_spec_ext_info pac1921_ext_info_current[] = {
@@ -894,7 +911,7 @@ static const struct iio_chan_spec_ext_info pac1921_ext_info_current[] = {
.write = pac1921_write_shunt_resistor,
.shared = IIO_SEPARATE,
},
- {}
+ { }
};
static const struct iio_event_spec pac1921_overflow_event[] = {
@@ -1027,7 +1044,8 @@ static irqreturn_t pac1921_trigger_handler(int irq, void *p)
priv->scan.chan[ch++] = val;
}
- iio_push_to_buffers_with_timestamp(idev, &priv->scan, pf->timestamp);
+ iio_push_to_buffers_with_ts(idev, &priv->scan, sizeof(priv->scan),
+ pf->timestamp);
done:
iio_trigger_notify_done(idev->trig);
@@ -1077,7 +1095,7 @@ static int pac1921_init(struct pac1921_priv *priv)
/*
* Init control register:
* - VPower free run integration mode
- * - OUT pin full scale range: 3V (HW detault)
+ * - OUT pin full scale range: 3V (HW default)
* - no timeout, no sleep, no sleep override, no recalc (HW defaults)
*/
val = FIELD_PREP(PAC1921_CONTROL_MXSL_MASK,
@@ -1151,6 +1169,61 @@ static void pac1921_regulator_disable(void *data)
regulator_disable(regulator);
}
+/*
+ * Documentation related to the ACPI device definition
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ApplicationNotes/ApplicationNotes/PAC193X-Integration-Notes-for-Microsoft-Windows-10-and-Windows-11-Driver-Support-DS00002534.pdf
+ */
+static int pac1921_match_acpi_device(struct iio_dev *indio_dev)
+{
+ acpi_handle handle;
+ union acpi_object *status;
+ char *label;
+ struct pac1921_priv *priv = iio_priv(indio_dev);
+ struct device *dev = &priv->client->dev;
+
+ handle = ACPI_HANDLE(dev);
+
+ status = acpi_evaluate_dsm(handle, &pac1921_guid, 1,
+ PAC1921_ACPI_GET_uOHMS_VALS, NULL);
+ if (!status)
+ return dev_err_probe(dev, -EINVAL,
+ "Could not read shunt from ACPI table\n");
+
+ priv->rshunt_uohm = status->package.elements[0].integer.value;
+ ACPI_FREE(status);
+
+ status = acpi_evaluate_dsm(handle, &pac1921_guid, 1,
+ PAC1921_ACPI_GET_LABEL, NULL);
+ if (!status)
+ return dev_err_probe(dev, -EINVAL,
+ "Could not read label from ACPI table\n");
+
+ label = devm_kstrdup(dev, status->package.elements[0].string.pointer,
+ GFP_KERNEL);
+ ACPI_FREE(status);
+ if (!label)
+ return -ENOMEM;
+
+ indio_dev->label = label;
+
+ return 0;
+}
+
+static int pac1921_parse_of_fw(struct iio_dev *indio_dev)
+{
+ int ret;
+ struct pac1921_priv *priv = iio_priv(indio_dev);
+ struct device *dev = &priv->client->dev;
+
+ ret = device_property_read_u32(dev, "shunt-resistor-micro-ohms",
+ &priv->rshunt_uohm);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Cannot read shunt resistor property\n");
+
+ return 0;
+}
+
static int pac1921_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
@@ -1168,20 +1241,25 @@ static int pac1921_probe(struct i2c_client *client)
priv->regmap = devm_regmap_init_i2c(client, &pac1921_regmap_config);
if (IS_ERR(priv->regmap))
- return dev_err_probe(dev, (int)PTR_ERR(priv->regmap),
+ return dev_err_probe(dev, PTR_ERR(priv->regmap),
"Cannot initialize register map\n");
- devm_mutex_init(dev, &priv->lock);
+ ret = devm_mutex_init(dev, &priv->lock);
+ if (ret)
+ return ret;
priv->dv_gain = PAC1921_DEFAULT_DV_GAIN;
priv->di_gain = PAC1921_DEFAULT_DI_GAIN;
priv->n_samples = PAC1921_DEFAULT_NUM_SAMPLES;
- ret = device_property_read_u32(dev, "shunt-resistor-micro-ohms",
- &priv->rshunt_uohm);
+ if (is_acpi_device_node(dev->fwnode))
+ ret = pac1921_match_acpi_device(indio_dev);
+ else
+ ret = pac1921_parse_of_fw(indio_dev);
if (ret)
return dev_err_probe(dev, ret,
- "Cannot read shunt resistor property\n");
+ "Parameter parsing error\n");
+
if (priv->rshunt_uohm == 0 || priv->rshunt_uohm > INT_MAX)
return dev_err_probe(dev, -EINVAL,
"Invalid shunt resistor: %u\n",
@@ -1191,7 +1269,7 @@ static int pac1921_probe(struct i2c_client *client)
priv->vdd = devm_regulator_get(dev, "vdd");
if (IS_ERR(priv->vdd))
- return dev_err_probe(dev, (int)PTR_ERR(priv->vdd),
+ return dev_err_probe(dev, PTR_ERR(priv->vdd),
"Cannot get vdd regulator\n");
ret = regulator_enable(priv->vdd);
@@ -1201,8 +1279,7 @@ static int pac1921_probe(struct i2c_client *client)
ret = devm_add_action_or_reset(dev, pac1921_regulator_disable,
priv->vdd);
if (ret)
- return dev_err_probe(dev, ret,
- "Cannot add action for vdd regulator disposal\n");
+ return ret;
msleep(PAC1921_POWERUP_TIME_MS);
@@ -1244,11 +1321,18 @@ static const struct of_device_id pac1921_of_match[] = {
};
MODULE_DEVICE_TABLE(of, pac1921_of_match);
+static const struct acpi_device_id pac1921_acpi_match[] = {
+ { "MCHP1921" },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, pac1921_acpi_match);
+
static struct i2c_driver pac1921_driver = {
.driver = {
.name = "pac1921",
.pm = pm_sleep_ptr(&pac1921_pm_ops),
.of_match_table = pac1921_of_match,
+ .acpi_match_table = pac1921_acpi_match,
},
.probe = pac1921_probe,
.id_table = pac1921_id,
generated by cgit (git 2.34.1) at 2025-12-25 08:21:53 +0000