From: Victor Duicu <victor.duicu@xxxxxxxxxxxxx>
This patch implements ACPI support for pac1921.
Driver can read shunt resistor value and device name from ACPI table.
Signed-off-by: Victor Duicu <victor.duicu@xxxxxxxxxxxxx>
---
drivers/iio/adc/pac1921.c | 116 +++++++++++++++++++++++++++++++-------
1 file changed, 97 insertions(+), 19 deletions(-)
diff --git a/drivers/iio/adc/pac1921.c b/drivers/iio/adc/pac1921.c
index 4c2a1c07bc39..9bb61b88aaef 100644
--- a/drivers/iio/adc/pac1921.c
+++ b/drivers/iio/adc/pac1921.c
@@ -67,6 +67,10 @@ 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_NAME 1
+#define PAC1921_DSM_UUID "f7bb9932-86ee-4516-a236-7a7a742e55cb"
+
/*
* Pre-computed scale factors for BUS voltage
* format: IIO_VAL_INT_PLUS_NANO
@@ -190,6 +194,7 @@ struct pac1921_priv {
u8 n_samples;
u8 prev_ovf_flags;
u8 ovf_enabled_events;
+ char *name;
bool first_integr_started;
bool first_integr_done;
@@ -1151,6 +1156,79 @@ static void pac1921_regulator_disable(void *data)
regulator_disable(regulator);
}
+static int pac1921_match_acpi_device(struct i2c_client *client, struct pac1921_priv *priv)
+{
+ const struct acpi_device_id *device_pointer;
+ acpi_handle handle;
+ union acpi_object *rez;
+ guid_t guid;
+ struct device *dev = &client->dev;
+
+ guid_parse(PAC1921_DSM_UUID, &guid);
+ handle = ACPI_HANDLE(&client->dev);
+
+ device_pointer = acpi_match_device(dev->driver->acpi_match_table, dev);
+ if (!device_pointer)
+ return -EINVAL;
+
+ rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1921_ACPI_GET_UOHMS_VALS, NULL);
+ if (!rez)
+ return dev_err_probe(&client->dev, -EINVAL,
+ "Could not read shunt from ACPI table\n");
+
+ priv->rshunt_uohm = rez->package.elements[0].integer.value;
+ ACPI_FREE(rez);
+
+ if (priv->rshunt_uohm == 0)
+ return dev_err_probe(&client->dev, -EINVAL, "Shunt value is 0.");
+
+ pac1921_calc_current_scales(priv);
+
+ rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1921_ACPI_GET_NAME, NULL);
+ if (!rez) {
+ priv->name = "";
+ return dev_err_probe(&client->dev, -EINVAL,
+ "Could not read name from ACPI table\n");
+ }
+
+ priv->name = devm_kmemdup(&client->dev, rez->package.elements->string.pointer,
+ (size_t)rez->package.elements->string.length + 1,
+ GFP_KERNEL);
+ priv->name[rez->package.elements->string.length] = '\0';
+ ACPI_FREE(rez);
+
+ return 0;
+}
+
+static int pac1921_match_of_device(struct i2c_client *client, struct pac1921_priv *priv)
+{
+ int ret;
+ struct device *dev = &client->dev;
+
+ /* Read shunt resistor value */
+ 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");
+
+ if (priv->rshunt_uohm == 0 || priv->rshunt_uohm > INT_MAX)
+ return dev_err_probe(dev, -EINVAL, "Invalid shunt resistor: %u\n",
+ priv->rshunt_uohm);
+
+ pac1921_calc_current_scales(priv);
+
+ if (device_property_present(dev, "name")) {
+ ret = device_property_read_string(dev, "name", (const char **)&priv->name);
+ if (ret)
+ return dev_err_probe(&client->dev, ret,
+ "Invalid rail-name value\n");
+ } else {
+ priv->name = "pac1921";
+ }
+
+ return 0;
+}
+
static int pac1921_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
@@ -1172,22 +1250,14 @@ static int pac1921_probe(struct i2c_client *client)
"Cannot initialize register map\n");
devm_mutex_init(dev, &priv->lock);
+ if (ACPI_HANDLE(&client->dev))
+ ret = pac1921_match_acpi_device(client, priv);
+ else
+ ret = pac1921_match_of_device(client, priv);
- 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 (ret)
- return dev_err_probe(dev, ret,
- "Cannot read shunt resistor property\n");
- if (priv->rshunt_uohm == 0 || priv->rshunt_uohm > INT_MAX)
- return dev_err_probe(dev, -EINVAL,
- "Invalid shunt resistor: %u\n",
- priv->rshunt_uohm);
-
- pac1921_calc_current_scales(priv);
+ if (ret < 0)
+ return dev_err_probe(&client->dev, ret,
+ "parameter parsing error\n");
priv->vdd = devm_regulator_get(dev, "vdd");
if (IS_ERR(priv->vdd))
@@ -1198,13 +1268,15 @@ static int pac1921_probe(struct i2c_client *client)
if (ret)
return dev_err_probe(dev, ret, "Cannot enable vdd regulator\n");
- ret = devm_add_action_or_reset(dev, pac1921_regulator_disable,
- priv->vdd);
+ 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");
+ "Cannot add action for vdd regulator disposal\n");
msleep(PAC1921_POWERUP_TIME_MS);
+ priv->dv_gain = PAC1921_DEFAULT_DV_GAIN;
+ priv->di_gain = PAC1921_DEFAULT_DI_GAIN;
+ priv->n_samples = PAC1921_DEFAULT_NUM_SAMPLES;
ret = pac1921_init(priv);
if (ret)
@@ -1212,7 +1284,7 @@ static int pac1921_probe(struct i2c_client *client)
priv->iio_info = pac1921_iio;
- indio_dev->name = "pac1921";
+ indio_dev->name = priv->name;
indio_dev->info = &priv->iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = pac1921_channels;
@@ -1244,11 +1316,17 @@ 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,
base-commit: fec496684388685647652ab4213454fbabdab099
--
2.43.0
