--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ADL8113 Low Noise Amplifier with integrated bypass switches
+ *
+ * Copyright 2025 Analog Devices Inc.
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitmap.h>
+#include <linux/device/driver.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+
+enum adl8113_signal_path {
+ ADL8113_INTERNAL_AMP,
+ ADL8113_INTERNAL_BYPASS,
+ ADL8113_EXTERNAL_A,
+ ADL8113_EXTERNAL_B,
+};
+
+struct adl8113_gain_config {
+ enum adl8113_signal_path path;
+ int gain_db;
+};
+
+struct adl8113_state {
+ struct gpio_descs *gpios;
+ struct adl8113_gain_config *gain_configs;
+ unsigned int num_gain_configs;
+ enum adl8113_signal_path current_path;
+};
+
+static const char * const adl8113_supply_names[] = {
+ "vdd1",
+ "vss2",
+ "vdd2",
+};
+
+static int adl8113_set_path(struct adl8113_state *st,
+ enum adl8113_signal_path path)
+{
+ DECLARE_BITMAP(values, 2);
+ int ret;
+
+ /*
+ * Determine GPIO values based on signal path.
+ * Va: bit 0, Vb: bit 1.
+ */
+ switch (path) {
+ case ADL8113_INTERNAL_AMP:
+ bitmap_write(values, 0x00, 0, 2);
+ break;
+ case ADL8113_INTERNAL_BYPASS:
+ bitmap_write(values, 0x03, 0, 2);
+ break;
+ case ADL8113_EXTERNAL_A:
+ bitmap_write(values, 0x02, 0, 2);
+ break;
+ case ADL8113_EXTERNAL_B:
+ bitmap_write(values, 0x01, 0, 2);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = gpiod_set_array_value_cansleep(st->gpios->ndescs, st->gpios->desc,
+ st->gpios->info, values);
+ if (ret)
+ return ret;
+
+ st->current_path = path;
+ return 0;
+}
+
+static int adl8113_find_gain_config(struct adl8113_state *st, int gain_db)
+{
+ unsigned int i;
+
+ for (i = 0; i < st->num_gain_configs; i++) {
+ if (st->gain_configs[i].gain_db == gain_db)
+ return i;
+ }
+ return -EINVAL;
+}
+
+static const struct iio_chan_spec adl8113_channels[] = {
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_HARDWAREGAIN),
+ },
+};
+
+static int adl8113_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct adl8113_state *st = iio_priv(indio_dev);
+ unsigned int i;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ /* Find current gain configuration */
+ for (i = 0; i < st->num_gain_configs; i++) {
+ if (st->gain_configs[i].path == st->current_path) {
+ *val = st->gain_configs[i].gain_db;
+ *val2 = 0;
+ return IIO_VAL_INT_PLUS_MICRO_DB;
+ }
+ }
+ return -EINVAL;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int adl8113_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct adl8113_state *st = iio_priv(indio_dev);
+ int config_idx;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_HARDWAREGAIN:
+ if (val2 != 0)
+ return -EINVAL;
+
+ config_idx = adl8113_find_gain_config(st, val);
+ if (config_idx < 0)
+ return config_idx;
+
+ return adl8113_set_path(st, st->gain_configs[config_idx].path);
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info adl8113_info = {
+ .read_raw = adl8113_read_raw,
+ .write_raw = adl8113_write_raw,
+};
+
+static int adl8113_init_gain_configs(struct device *dev, struct adl8113_state *st)
+{
+ int external_a_gain, external_b_gain;
+ unsigned int i;
+
+ /*
+ * Allocate for all 4 possible paths:
+ * - Internal amp and bypass (always present)
+ * - External bypass A and B (optional if configured)
+ */
+ st->gain_configs = devm_kcalloc(dev, 4, sizeof(*st->gain_configs),
+ GFP_KERNEL);
+ if (!st->gain_configs)
+ return -ENOMEM;
+
+ /* Start filling the gain configurations with data */
+ i = 0;
+
+ /* Always include internal amplifier (14dB) */
+ st->gain_configs[i++] = (struct adl8113_gain_config) {
+ .path = ADL8113_INTERNAL_AMP,
+ .gain_db = 14,
+ };
+
+ /* Always include internal bypass (-2dB insertion loss) */
+ st->gain_configs[i++] = (struct adl8113_gain_config) {
+ .path = ADL8113_INTERNAL_BYPASS,
+ .gain_db = -2,
+ };
+
+ /* Add external bypass A if configured */
+ if (!device_property_read_u32(dev, "adi,external-bypass-a-gain-db",
+ &external_a_gain)) {
+ st->gain_configs[i++] = (struct adl8113_gain_config) {
+ .path = ADL8113_EXTERNAL_A,
+ .gain_db = external_a_gain,
+ };
+ }
+
+ /* Add external bypass B if configured */
+ if (!device_property_read_u32(dev, "adi,external-bypass-b-gain-db",
+ &external_b_gain)) {
+ st->gain_configs[i++] = (struct adl8113_gain_config) {
+ .path = ADL8113_EXTERNAL_B,
+ .gain_db = external_b_gain,
+ };
+ }
+
+ st->num_gain_configs = i;
+
+ return 0;
+}
+
+static int adl8113_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct adl8113_state *st;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ st->gpios = devm_gpiod_get_array(dev, "ctrl", GPIOD_OUT_LOW);
+ if (IS_ERR(st->gpios))
+ return dev_err_probe(dev, PTR_ERR(st->gpios),
+ "failed to get control GPIOs\n");
+
+ if (st->gpios->ndescs != 2)
+ return dev_err_probe(dev, -EINVAL,
+ "expected 2 control GPIOs, got %u\n",
+ st->gpios->ndescs);
+
+ ret = devm_regulator_bulk_get_enable(dev,
+ ARRAY_SIZE(adl8113_supply_names),
+ adl8113_supply_names);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to get and enable supplies\n");
+
+ /* Initialize gain configurations from devicetree */
+ ret = adl8113_init_gain_configs(dev, st);
+ if (ret)
+ return ret;
+
+ /* Initialize to internal amplifier path (14dB) */
+ ret = adl8113_set_path(st, ADL8113_INTERNAL_AMP);
+ if (ret)
+ return ret;
+
+ indio_dev->info = &adl8113_info;
+ indio_dev->name = "adl8113";
+ indio_dev->channels = adl8113_channels;
+ indio_dev->num_channels = ARRAY_SIZE(adl8113_channels);
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id adl8113_of_match[] = {
+ { .compatible = "adi,adl8113" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, adl8113_of_match);
+
+static struct platform_driver adl8113_driver = {
+ .driver = {
+ .name = "adl8113",
+ .of_match_table = adl8113_of_match,
+ },
+ .probe = adl8113_probe,
+};
+module_platform_driver(adl8113_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADL8113 Low Noise Amplifier");
+MODULE_LICENSE("GPL");
projects / thirdparty / kernel / linux.git / commitdiff
