diff options
| -rw-r--r-- | doc/device-tree-bindings/adc/adc.txt | 62 | ||||
| -rw-r--r-- | drivers/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/Makefile | 1 | ||||
| -rw-r--r-- | drivers/adc/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/adc/Makefile | 8 | ||||
| -rw-r--r-- | drivers/adc/adc-uclass.c | 409 | ||||
| -rw-r--r-- | include/adc.h | 288 | ||||
| -rw-r--r-- | include/dm/uclass-id.h | 1 |
8 files changed, 783 insertions, 0 deletions
diff --git a/doc/device-tree-bindings/adc/adc.txt b/doc/device-tree-bindings/adc/adc.txt new file mode 100644 index 0000000000..463de3c8c2 --- /dev/null +++ b/doc/device-tree-bindings/adc/adc.txt @@ -0,0 +1,62 @@ +ADC device binding + +There are no mandatory properties for ADC. However, if Voltage info is required, +then there are two options: +- use microvolts constraint or +- use regulator phandle to enable/read supply's Voltage + +Properties and constraints: +*optional and always checked, Voltage polarity info: +- vdd-polarity-negative: positive reference Voltage has a negative polarity +- vss-polarity-negative: negative reference Voltage has a negative polarity + +Chose one option, for each supply (Vdd/Vss): + +*optional and always checked, supply Voltage constants: +- vdd-supply: phandle to Vdd regulator's node +- vss-supply: phandle to Vss regulator's node + +*optional and checked only if the above corresponding, doesn't exist: +- vdd-microvolts: positive reference Voltage value [uV] +- vss-microvolts: negative reference Voltage value [uV] + +Example with constant 'Vdd' value: +adc@1000000 { + compatible = "some-adc"; + reg = <0xaabb000 0x100>; + status = "enabled"; + vdd-microvolts = <1800000>; +}; + +Example of supply phandle usage, for the ADC's VDD/VSS references as below: + _______ _______ + |Sandbox| |Sandbox| + : PMIC : : ADC : + . . . . + | | (Vdd) | AIN0|--> + | BUCK2|-------|VDDref | + | (3.3V)| _|VSSref | + |_______| | |_______| + _|_ + +For the above PMIC, the node can be defined as follows: +sandbox_pmic { + compatible = "sandbox,pmic"; + ... + buck2: buck2 { + regulator-name = "SUPPLY_3.3V"; + regulator-min-microvolt = <3300000>; + regulator-max-microvolt = <3300000>; + }; + ... +}; + +For the above ADC, the node can be defined as follows: +adc@0 { + compatible = "sandbox,adc"; + vdd-supply = <&buck2>; + vss-microvolts = <0>; +}; + +The ADC uclass code, will enable the supply before start of the conversion, +but it will not configure the regulator settings. diff --git a/drivers/Kconfig b/drivers/Kconfig index ba88b5ea37..c481e93356 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -4,6 +4,8 @@ source "drivers/core/Kconfig" # types of drivers sorted in alphabetical order +source "drivers/adc/Kconfig" + source "drivers/block/Kconfig" source "drivers/clk/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 4f49bfddb8..ad29a4fd04 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -35,6 +35,7 @@ obj-$(CONFIG_SPL_SATA_SUPPORT) += block/ else +obj-y += adc/ obj-$(CONFIG_DM_DEMO) += demo/ obj-$(CONFIG_BIOSEMU) += bios_emulator/ obj-y += block/ diff --git a/drivers/adc/Kconfig b/drivers/adc/Kconfig new file mode 100644 index 0000000000..b6e226a5c4 --- /dev/null +++ b/drivers/adc/Kconfig @@ -0,0 +1,12 @@ +config ADC + bool "Enable ADC drivers using Driver Model" + help + This enables ADC API for drivers, which allows driving ADC features + by single and multi-channel methods for: + - start/stop/get data for conversion of a single-channel selected by + a number or multi-channels selected by a bitmask + - get data mask (ADC resolution) + ADC reference Voltage supply options: + - methods for get Vdd/Vss reference Voltage values with polarity + - support supply's phandle with auto-enable + - supply polarity setting in fdt diff --git a/drivers/adc/Makefile b/drivers/adc/Makefile new file mode 100644 index 0000000000..c4d9618ec3 --- /dev/null +++ b/drivers/adc/Makefile @@ -0,0 +1,8 @@ +# +# Copyright (C) 2015 Samsung Electronics +# Przemyslaw Marczak <p.marczak@samsung.com> +# +# SPDX-License-Identifier: GPL-2.0+ +# + +obj-$(CONFIG_ADC) += adc-uclass.o diff --git a/drivers/adc/adc-uclass.c b/drivers/adc/adc-uclass.c new file mode 100644 index 0000000000..9233fcdb6c --- /dev/null +++ b/drivers/adc/adc-uclass.c @@ -0,0 +1,409 @@ +/* + * Copyright (C) 2015 Samsung Electronics + * Przemyslaw Marczak <p.marczak@samsung.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <errno.h> +#include <dm.h> +#include <dm/lists.h> +#include <dm/device-internal.h> +#include <dm/uclass-internal.h> +#include <adc.h> +#include <power/regulator.h> + +DECLARE_GLOBAL_DATA_PTR; + +#define ADC_UCLASS_PLATDATA_SIZE sizeof(struct adc_uclass_platdata) +#define CHECK_NUMBER true +#define CHECK_MASK (!CHECK_NUMBER) + +/* TODO: add support for timer uclass (for early calls) */ +#ifdef CONFIG_SANDBOX_ARCH +#define sdelay(x) udelay(x) +#else +extern void sdelay(unsigned long loops); +#endif + +static int check_channel(struct udevice *dev, int value, bool number_or_mask, + const char *caller_function) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + unsigned mask = number_or_mask ? (1 << value) : value; + + /* For the real ADC hardware, some ADC channels can be inactive. + * For example if device has 4 analog channels, and only channels + * 1-st and 3-rd are valid, then channel mask is: 0b1010, so request + * with mask 0b1110 should return an error. + */ + if ((uc_pdata->channel_mask >= mask) && (uc_pdata->channel_mask & mask)) + return 0; + + printf("Error in %s/%s().\nWrong channel selection for device: %s\n", + __FILE__, caller_function, dev->name); + + return -EINVAL; +} + +static int adc_supply_enable(struct udevice *dev) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + const char *supply_type; + int ret = 0; + + if (uc_pdata->vdd_supply) { + supply_type = "vdd"; + ret = regulator_set_enable(uc_pdata->vdd_supply, true); + } + + if (!ret && uc_pdata->vss_supply) { + supply_type = "vss"; + ret = regulator_set_enable(uc_pdata->vss_supply, true); + } + + if (ret) + error("%s: can't enable %s-supply!", dev->name, supply_type); + + return ret; +} + +int adc_data_mask(struct udevice *dev, unsigned int *data_mask) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + + if (!uc_pdata) + return -ENOSYS; + + *data_mask = uc_pdata->data_mask; + return 0; +} + +int adc_stop(struct udevice *dev) +{ + const struct adc_ops *ops = dev_get_driver_ops(dev); + + if (!ops->stop) + return -ENOSYS; + + return ops->stop(dev); +} + +int adc_start_channel(struct udevice *dev, int channel) +{ + const struct adc_ops *ops = dev_get_driver_ops(dev); + int ret; + + if (!ops->start_channel) + return -ENOSYS; + + ret = check_channel(dev, channel, CHECK_NUMBER, __func__); + if (ret) + return ret; + + ret = adc_supply_enable(dev); + if (ret) + return ret; + + return ops->start_channel(dev, channel); +} + +int adc_start_channels(struct udevice *dev, unsigned int channel_mask) +{ + const struct adc_ops *ops = dev_get_driver_ops(dev); + int ret; + + if (!ops->start_channels) + return -ENOSYS; + + ret = check_channel(dev, channel_mask, CHECK_MASK, __func__); + if (ret) + return ret; + + ret = adc_supply_enable(dev); + if (ret) + return ret; + + return ops->start_channels(dev, channel_mask); +} + +int adc_channel_data(struct udevice *dev, int channel, unsigned int *data) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + const struct adc_ops *ops = dev_get_driver_ops(dev); + unsigned int timeout_us = uc_pdata->data_timeout_us; + int ret; + + if (!ops->channel_data) + return -ENOSYS; + + ret = check_channel(dev, channel, CHECK_NUMBER, __func__); + if (ret) + return ret; + + do { + ret = ops->channel_data(dev, channel, data); + if (!ret || ret != -EBUSY) + break; + + /* TODO: use timer uclass (for early calls). */ + sdelay(5); + } while (timeout_us--); + + return ret; +} + +int adc_channels_data(struct udevice *dev, unsigned int channel_mask, + struct adc_channel *channels) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + unsigned int timeout_us = uc_pdata->multidata_timeout_us; + const struct adc_ops *ops = dev_get_driver_ops(dev); + int ret; + + if (!ops->channels_data) + return -ENOSYS; + + ret = check_channel(dev, channel_mask, CHECK_MASK, __func__); + if (ret) + return ret; + + do { + ret = ops->channels_data(dev, channel_mask, channels); + if (!ret || ret != -EBUSY) + break; + + /* TODO: use timer uclass (for early calls). */ + sdelay(5); + } while (timeout_us--); + + return ret; +} + +int adc_channel_single_shot(const char *name, int channel, unsigned int *data) +{ + struct udevice *dev; + int ret; + + ret = uclass_get_device_by_name(UCLASS_ADC, name, &dev); + if (ret) + return ret; + + ret = adc_start_channel(dev, channel); + if (ret) + return ret; + + ret = adc_channel_data(dev, channel, data); + if (ret) + return ret; + + return 0; +} + +static int _adc_channels_single_shot(struct udevice *dev, + unsigned int channel_mask, + struct adc_channel *channels) +{ + unsigned int data; + int channel, ret; + + for (channel = 0; channel <= ADC_MAX_CHANNEL; channel++) { + /* Check channel bit. */ + if (!((channel_mask >> channel) & 0x1)) + continue; + + ret = adc_start_channel(dev, channel); + if (ret) + return ret; + + ret = adc_channel_data(dev, channel, &data); + if (ret) + return ret; + + channels->id = channel; + channels->data = data; + channels++; + } + + return 0; +} + +int adc_channels_single_shot(const char *name, unsigned int channel_mask, + struct adc_channel *channels) +{ + struct udevice *dev; + int ret; + + ret = uclass_get_device_by_name(UCLASS_ADC, name, &dev); + if (ret) + return ret; + + ret = adc_start_channels(dev, channel_mask); + if (ret) + goto try_manual; + + ret = adc_channels_data(dev, channel_mask, channels); + if (ret) + return ret; + + return 0; + +try_manual: + if (ret != -ENOSYS) + return ret; + + return _adc_channels_single_shot(dev, channel_mask, channels); +} + +static int adc_vdd_platdata_update(struct udevice *dev) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + int ret; + + /* Warning! + * This function can't return supply device before its bind. + * Please pay attention to proper fdt scan sequence. If ADC device + * will bind before its supply regulator device, then the below 'get' + * will return an error. + */ + ret = device_get_supply_regulator(dev, "vdd-supply", + &uc_pdata->vdd_supply); + if (ret) + return ret; + + ret = regulator_get_value(uc_pdata->vdd_supply); + if (ret < 0) + return ret; + + uc_pdata->vdd_microvolts = ret; + + return 0; +} + +static int adc_vss_platdata_update(struct udevice *dev) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + int ret; + + ret = device_get_supply_regulator(dev, "vss-supply", + &uc_pdata->vss_supply); + if (ret) + return ret; + + ret = regulator_get_value(uc_pdata->vss_supply); + if (ret < 0) + return ret; + + uc_pdata->vss_microvolts = ret; + + return 0; +} + +int adc_vdd_value(struct udevice *dev, int *uV) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + int ret, value_sign = uc_pdata->vdd_polarity_negative ? -1 : 1; + + if (!uc_pdata->vdd_supply) + goto nodev; + + /* Update the regulator Value. */ + ret = adc_vdd_platdata_update(dev); + if (ret) + return ret; +nodev: + if (uc_pdata->vdd_microvolts == -ENODATA) + return -ENODATA; + + *uV = uc_pdata->vdd_microvolts * value_sign; + + return 0; +} + +int adc_vss_value(struct udevice *dev, int *uV) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + int ret, value_sign = uc_pdata->vss_polarity_negative ? -1 : 1; + + if (!uc_pdata->vss_supply) + goto nodev; + + /* Update the regulator Value. */ + ret = adc_vss_platdata_update(dev); + if (ret) + return ret; +nodev: + if (uc_pdata->vss_microvolts == -ENODATA) + return -ENODATA; + + *uV = uc_pdata->vss_microvolts * value_sign; + + return 0; +} + +static int adc_vdd_platdata_set(struct udevice *dev) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + int ret, offset = dev->of_offset; + const void *fdt = gd->fdt_blob; + char *prop; + + prop = "vdd-polarity-negative"; + uc_pdata->vdd_polarity_negative = fdtdec_get_bool(fdt, offset, prop); + + ret = adc_vdd_platdata_update(dev); + if (ret != -ENOENT) + return ret; + + /* No vdd-supply phandle. */ + prop = "vdd-microvolts"; + uc_pdata->vdd_microvolts = fdtdec_get_int(fdt, offset, prop, -ENODATA); + + return 0; +} + +static int adc_vss_platdata_set(struct udevice *dev) +{ + struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev); + int ret, offset = dev->of_offset; + const void *fdt = gd->fdt_blob; + char *prop; + + prop = "vss-polarity-negative"; + uc_pdata->vss_polarity_negative = fdtdec_get_bool(fdt, offset, prop); + + ret = adc_vss_platdata_update(dev); + if (ret != -ENOENT) + return ret; + + /* No vss-supply phandle. */ + prop = "vss-microvolts"; + uc_pdata->vss_microvolts = fdtdec_get_int(fdt, offset, prop, -ENODATA); + + return 0; +} + +static int adc_pre_probe(struct udevice *dev) +{ + int ret; + + /* Set ADC VDD platdata: polarity, uV, regulator (phandle). */ + ret = adc_vdd_platdata_set(dev); + if (ret) + error("%s: Can't update Vdd. Error: %d", dev->name, ret); + + /* Set ADC VSS platdata: polarity, uV, regulator (phandle). */ + ret = adc_vss_platdata_set(dev); + if (ret) + error("%s: Can't update Vss. Error: %d", dev->name, ret); + + return 0; +} + +UCLASS_DRIVER(adc) = { + .id = UCLASS_ADC, + .name = "adc", + .pre_probe = adc_pre_probe, + .per_device_platdata_auto_alloc_size = ADC_UCLASS_PLATDATA_SIZE, +}; diff --git a/include/adc.h b/include/adc.h new file mode 100644 index 0000000000..4b14017849 --- /dev/null +++ b/include/adc.h @@ -0,0 +1,288 @@ +/* + * Copyright (C) 2015 Samsung Electronics + * Przemyslaw Marczak <p.marczak@samsung.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef _ADC_H_ +#define _ADC_H_ + +/* ADC_CHANNEL() - ADC channel bit mask, to select only required channels */ +#define ADC_CHANNEL(x) (1 << x) + +/* The last possible selected channel with 32-bit mask */ +#define ADC_MAX_CHANNEL 31 + +/** + * adc_data_format: define the ADC output data format, can be useful when + * the device's input Voltage range is bipolar. + * - ADC_DATA_FORMAT_BIN - binary offset + * - ADC_DATA_FORMAT_2S - two's complement + * + * Note: Device's driver should fill the 'data_format' field of its uclass's + * platform data using one of the above data format types. + */ +enum adc_data_format { + ADC_DATA_FORMAT_BIN, + ADC_DATA_FORMAT_2S, +}; + +/** + * struct adc_channel - structure to hold channel conversion data. + * Useful to keep the result of a multi-channel conversion output. + * + * @id - channel id + * @data - channel conversion data + */ +struct adc_channel { + int id; + unsigned int data; +}; + +/** + * struct adc_uclass_platdata - basic ADC info + * + * Note: The positive/negative reference Voltage is only a name and it doesn't + * provide an information about the value polarity. It is possible, for both + * values to be a negative or positive. For this purpose the uclass's platform + * data provides a bool fields: 'vdd/vss_supply_is_negative'. This is useful, + * since the regulator API returns only a positive Voltage values. + * + * To get the reference Voltage values with polarity, use functions: + * - adc_vdd_value() + * - adc_vss_value() + * Those are useful for some cases of ADC's references, e.g.: + * * Vdd: +3.3V; Vss: -3.3V -> 6.6 Vdiff + * * Vdd: +3.3V; Vss: +0.3V -> 3.0 Vdiff + * * Vdd: +3.3V; Vss: 0.0V -> 3.3 Vdiff + * The last one is usually standard and doesn't require the fdt polarity info. + * + * For more informations read binding info: + * - doc/device-tree-bindings/adc/adc.txt + * + * @data_mask - conversion output data mask + * @data_timeout_us - single channel conversion timeout + * @multidata_timeout_us - multi channel conversion timeout + * @channel_mask - bit mask of available channels [0:31] + * @vdd_supply - positive reference Voltage supply (regulator) + * @vss_supply - negative reference Voltage supply (regulator) + * @vdd_polarity_negative - positive reference Voltage has negative polarity + * @vss_polarity_negative - negative reference Voltage has negative polarity + * @vdd_microvolts - positive reference Voltage value + * @vss_microvolts - negative reference Voltage value + */ +struct adc_uclass_platdata { + int data_format; + unsigned int data_mask; + unsigned int data_timeout_us; + unsigned int multidata_timeout_us; + unsigned int channel_mask; + struct udevice *vdd_supply; + struct udevice *vss_supply; + bool vdd_polarity_negative; + bool vss_polarity_negative; + int vdd_microvolts; + int vss_microvolts; +}; + +/** + * struct adc_ops - ADC device operations for single/multi-channel operation. + */ +struct adc_ops { + /** + * start_channel() - start conversion with its default parameters + * for the given channel number. + * + * @dev: ADC device to init + * @channel: analog channel number + * @return: 0 if OK, -ve on error + */ + int (*start_channel)(struct udevice *dev, int channel); + + /** + * start_channels() - start conversion with its default parameters + * for the channel numbers selected by the bit mask. + * + * This is optional, useful when the hardware supports multichannel + * conversion by the single software trigger. + * + * @dev: ADC device to init + * @channel_mask: bit mask of selected analog channels + * @return: 0 if OK, -ve on error + */ + int (*start_channels)(struct udevice *dev, unsigned int channel_mask); + + /** + * channel_data() - get conversion output data for the given channel. + * + * Note: The implementation of this function should only check, that + * the conversion data is available at the call time. If the hardware + * requires some delay to get the data, then this function should + * return with -EBUSY value. The ADC API will call it in a loop, + * until the data is available or the timeout expires. The maximum + * timeout for this operation is defined by the field 'data_timeout_us' + * in ADC uclasses platform data structure. + * + * @dev: ADC device to trigger + * @channel: selected analog channel number + * @data: returned pointer to selected channel's output data + * @return: 0 if OK, -EBUSY if busy, and other negative on error + */ + int (*channel_data)(struct udevice *dev, int channel, + unsigned int *data); + + /** + * channels_data() - get conversion data for the selected channels. + * + * This is optional, useful when multichannel conversion is supported + * by the hardware, by the single software trigger. + * + * For the proper implementation, please look at the 'Note' for the + * above method. The only difference is in used timeout value, which + * is defined by field 'multidata_timeout_us'. + * + * @dev: ADC device to trigger + * @channel_mask: bit mask of selected analog channels + * @channels: returned pointer to array of output data for channels + * selected by the given mask + * @return: 0 if OK, -ve on error + */ + int (*channels_data)(struct udevice *dev, unsigned int channel_mask, + struct adc_channel *channels); + + /** + * stop() - stop conversion of the given ADC device + * + * @dev: ADC device to stop + * @return: 0 if OK, -ve on error + */ + int (*stop)(struct udevice *dev); +}; + +/** + * adc_start_channel() - start conversion for given device/channel and exit. + * + * @dev: ADC device + * @channel: analog channel number + * @return: 0 if OK, -ve on error + */ +int adc_start_channel(struct udevice *dev, int channel); + +/** + * adc_start_channels() - start conversion for given device/channels and exit. + * + * Note: + * To use this function, device must implement method: start_channels(). + * + * @dev: ADC device to start + * @channel_mask: channel selection - a bit mask + * @channel_mask: bit mask of analog channels + * @return: 0 if OK, -ve on error + */ +int adc_start_channels(struct udevice *dev, unsigned int channel_mask); + +/** + * adc_channel_data() - get conversion data for the given device channel number. + * + * @dev: ADC device to read + * @channel: analog channel number + * @data: pointer to returned channel's data + * @return: 0 if OK, -ve on error + */ +int adc_channel_data(struct udevice *dev, int channel, unsigned int *data); + +/** + * adc_channels_data() - get conversion data for the channels selected by mask + * + * Note: + * To use this function, device must implement methods: + * - start_channels() + * - channels_data() + * + * @dev: ADC device to read + * @channel_mask: channel selection - a bit mask + * @channels: pointer to structure array of returned data for each channel + * @return: 0 if OK, -ve on error + */ +int adc_channels_data(struct udevice *dev, unsigned int channel_mask, + struct adc_channel *channels); + +/** + * adc_data_mask() - get data mask (ADC resolution bitmask) for given ADC device + * + * This can be used if adc uclass platform data is filled. + * + * @dev: ADC device to check + * @data_mask: pointer to the returned data bitmask + * @return: 0 if OK, -ve on error + */ +int adc_data_mask(struct udevice *dev, unsigned int *data_mask); + +/** + * adc_channel_single_shot() - get output data of conversion for the ADC + * device's channel. This function searches for the device with the given name, + * starts the given channel conversion and returns the output data. + * + * Note: To use this function, device must implement metods: + * - start_channel() + * - channel_data() + * + * @name: device's name to search + * @channel: device's input channel to init + * @data: pointer to conversion output data + * @return: 0 if OK, -ve on error + */ +int adc_channel_single_shot(const char *name, int channel, unsigned int *data); + +/** + * adc_channels_single_shot() - get ADC conversion output data for the selected + * device's channels. This function searches for the device by the given name, + * starts the selected channels conversion and returns the output data as array + * of type 'struct adc_channel'. + * + * Note: This function can be used if device implements one of ADC's single + * or multi-channel operation API. If multi-channel operation is not supported, + * then each selected channel is triggered by the sequence start/data in a loop. + * + * @name: device's name to search + * @channel_mask: channel selection - a bit mask + * @channels: pointer to conversion output data for the selected channels + * @return: 0 if OK, -ve on error + */ +int adc_channels_single_shot(const char *name, unsigned int channel_mask, + struct adc_channel *channels); + +/** + * adc_vdd_value() - get the ADC device's positive reference Voltage value + * + * Note: Depending on bool value 'vdd_supply_is_negative' of platform data, + * the returned uV value can be negative, and it's not an error. + * + * @dev: ADC device to check + * @uV: Voltage value with polarization sign (uV) + * @return: 0 on success or -ve on error +*/ +int adc_vdd_value(struct udevice *dev, int *uV); + +/** + * adc_vss_value() - get the ADC device's negative reference Voltage value + * + * Note: Depending on bool value 'vdd_supply_is_negative' of platform data, + * the returned uV value can be negative, and it's not an error. + * + * @dev: ADC device to check + * @uV: Voltage value with polarization sign (uV) + * @return: 0 on success or -ve on error +*/ +int adc_vss_value(struct udevice *dev, int *uV); + +/** + * adc_stop() - stop operation for given ADC device. + * + * @dev: ADC device to stop + * @return: 0 if OK, -ve on error + */ +int adc_stop(struct udevice *dev); + +#endif diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index 886a44c134..d0cf4ce6a0 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -25,6 +25,7 @@ enum uclass_id { UCLASS_SIMPLE_BUS, /* bus with child devices */ /* U-Boot uclasses start here - in alphabetical order */ + UCLASS_ADC, /* Analog-to-digital converter */ UCLASS_CLK, /* Clock source, e.g. used by peripherals */ UCLASS_CPU, /* CPU, typically part of an SoC */ UCLASS_CROS_EC, /* Chrome OS EC */ |
