Merge tag 'char-misc-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char / misc driver updates from Greg KH:
 "Here is the "big" set of char/misc and other driver subsystem changes
  for 6.12-rc1.

  Lots of changes in here, primarily dominated by the usual IIO driver
  updates and additions, but there are also small driver subsystem
  updates all over the place. Included in here are:

   - lots and lots of new IIO drivers and updates to existing ones

   - interconnect subsystem updates and new drivers

   - nvmem subsystem updates and new drivers

   - mhi driver updates

   - power supply subsystem updates

   - kobj_type const work for many different small subsystems

   - comedi driver fix

   - coresight subsystem and driver updates

   - fpga subsystem improvements

   - slimbus fixups

   - binder new feature addition for "frozen" notifications

   - lots and lots of other small driver updates and cleanups

  All of these have been in linux-next for a long time with no reported
  problems"

* tag 'char-misc-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (354 commits)
  greybus: gb-beagleplay: Add firmware upload API
  arm64: dts: ti: k3-am625-beagleplay: Add bootloader-backdoor-gpios to cc1352p7
  dt-bindings: net: ti,cc1352p7: Add bootloader-backdoor-gpios
  MAINTAINERS: Update path for U-Boot environment variables YAML
  nvmem: layouts: add U-Boot env layout
  comedi: ni_routing: tools: Check when the file could not be opened
  ocxl: Remove the unused declarations in headr file
  hpet: Fix the wrong format specifier
  uio: Constify struct kobj_type
  cxl: Constify struct kobj_type
  binder: modify the comment for binder_proc_unlock
  iio: adc: axp20x_adc: add support for AXP717 ADC
  dt-bindings: iio: adc: Add AXP717 compatible
  iio: adc: axp20x_adc: Add adc_en1 and adc_en2 to axp_data
  w1: ds2482: Drop explicit initialization of struct i2c_device_id::driver_data to 0
  tools: iio: rm .*.cmd when make clean
  iio: adc: standardize on formatting for id match tables
  iio: proximity: aw96103: Add support for aw96103/aw96105 proximity sensor
  bus: mhi: host: pci_generic: Enable EDL trigger for Foxconn modems
  bus: mhi: host: pci_generic: Update EDL firmware path for Foxconn modems
  ...

1 files changed, 96 insertions, 1 deletions

diff --git a/drivers/iio/adc/sd_adc_modulator.c b/drivers/iio/adc/sd_adc_modulator.c
index 327cc2097f6c..654b6a38b650 100644
--- a/drivers/iio/adc/sd_adc_modulator.c
+++ b/drivers/iio/adc/sd_adc_modulator.c
@@ -6,11 +6,14 @@
  * Author: Arnaud Pouliquen <arnaud.pouliquen@st.com>.
  */
 
+#include <linux/iio/backend.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
 
 static const struct iio_info iio_sd_mod_iio_info;
 
@@ -24,7 +27,59 @@ static const struct iio_chan_spec iio_sd_mod_ch = {
 	},
 };
 
-static int iio_sd_mod_probe(struct platform_device *pdev)
+struct iio_sd_backend_priv {
+	struct regulator *vref;
+	int vref_mv;
+};
+
+static int iio_sd_mod_enable(struct iio_backend *backend)
+{
+	struct iio_sd_backend_priv *priv = iio_backend_get_priv(backend);
+
+	if (priv->vref)
+		return regulator_enable(priv->vref);
+
+	return 0;
+};
+
+static void iio_sd_mod_disable(struct iio_backend *backend)
+{
+	struct iio_sd_backend_priv *priv = iio_backend_get_priv(backend);
+
+	if (priv->vref)
+		regulator_disable(priv->vref);
+};
+
+static int iio_sd_mod_read(struct iio_backend *backend, struct iio_chan_spec const *chan, int *val,
+			   int *val2, long mask)
+{
+	struct iio_sd_backend_priv *priv = iio_backend_get_priv(backend);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		*val = priv->vref_mv;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_OFFSET:
+		*val = 0;
+		return IIO_VAL_INT;
+	}
+
+	return -EOPNOTSUPP;
+};
+
+static const struct iio_backend_ops sd_backend_ops = {
+	.enable = iio_sd_mod_enable,
+	.disable = iio_sd_mod_disable,
+	.read_raw = iio_sd_mod_read,
+};
+
+static const struct iio_backend_info sd_backend_info = {
+	.name = "sd-modulator",
+	.ops = &sd_backend_ops,
+};
+
+static int iio_sd_mod_register(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct iio_dev *iio;
@@ -45,6 +100,45 @@ static int iio_sd_mod_probe(struct platform_device *pdev)
 	return devm_iio_device_register(&pdev->dev, iio);
 }
 
+static int iio_sd_mod_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regulator *vref;
+	struct iio_sd_backend_priv *priv;
+	int ret;
+
+	/* If sd modulator is not defined as an IIO backend device, fallback to legacy */
+	if (!device_property_present(dev, "#io-backend-cells"))
+		return iio_sd_mod_register(pdev);
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/*
+	 * Get regulator reference if any, but don't enable regulator right now.
+	 * Rely on enable and disable callbacks to manage regulator power.
+	 */
+	vref = devm_regulator_get_optional(dev, "vref");
+	if (IS_ERR(vref)) {
+		if (PTR_ERR(vref) != -ENODEV)
+			return dev_err_probe(dev, PTR_ERR(vref), "Failed to get vref\n");
+	} else {
+		/*
+		 * Retrieve voltage right now, as regulator_get_voltage() provides it whatever
+		 * the state of the regulator.
+		 */
+		ret = regulator_get_voltage(vref);
+		if (ret < 0)
+			return ret;
+
+		priv->vref = vref;
+		priv->vref_mv = ret / 1000;
+	}
+
+	return devm_iio_backend_register(&pdev->dev, &sd_backend_info, priv);
+};
+
 static const struct of_device_id sd_adc_of_match[] = {
 	{ .compatible = "sd-modulator" },
 	{ .compatible = "ads1201" },
@@ -65,3 +159,4 @@ module_platform_driver(iio_sd_mod_adc);
 MODULE_DESCRIPTION("Basic sigma delta modulator");
 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(IIO_BACKEND);