diff options
Diffstat (limited to 'drivers/iio/amplifiers/adl8113.c')
| -rw-r--r-- | drivers/iio/amplifiers/adl8113.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/drivers/iio/amplifiers/adl8113.c b/drivers/iio/amplifiers/adl8113.c new file mode 100644 index 000000000000..b8a431b6616b --- /dev/null +++ b/drivers/iio/amplifiers/adl8113.c @@ -0,0 +1,269 @@ +// 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"); |