root/drivers/iio/adc/intel_mrfld_adc.c
// SPDX-License-Identifier: GPL-2.0
/*
 * ADC driver for Basin Cove PMIC
 *
 * Copyright (C) 2012 Intel Corporation
 * Author: Bin Yang <bin.yang@intel.com>
 *
 * Rewritten for upstream by:
 *       Vincent Pelletier <plr.vincent@gmail.com>
 *       Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 */

#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/mfd/intel_soc_pmic.h>
#include <linux/mfd/intel_soc_pmic_mrfld.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#include <linux/iio/driver.h>
#include <linux/iio/iio.h>
#include <linux/iio/machine.h>

#include <linux/unaligned.h>

#define BCOVE_GPADCREQ                  0xDC
#define BCOVE_GPADCREQ_BUSY             BIT(0)
#define BCOVE_GPADCREQ_IRQEN            BIT(1)

#define BCOVE_ADCIRQ_ALL (              \
        BCOVE_ADCIRQ_BATTEMP |          \
        BCOVE_ADCIRQ_SYSTEMP |          \
        BCOVE_ADCIRQ_BATTID |           \
        BCOVE_ADCIRQ_VIBATT |           \
        BCOVE_ADCIRQ_CCTICK)

#define BCOVE_ADC_TIMEOUT               msecs_to_jiffies(1000)

static const u8 mrfld_adc_requests[] = {
        BCOVE_ADCIRQ_VIBATT,
        BCOVE_ADCIRQ_BATTID,
        BCOVE_ADCIRQ_VIBATT,
        BCOVE_ADCIRQ_SYSTEMP,
        BCOVE_ADCIRQ_BATTEMP,
        BCOVE_ADCIRQ_BATTEMP,
        BCOVE_ADCIRQ_SYSTEMP,
        BCOVE_ADCIRQ_SYSTEMP,
        BCOVE_ADCIRQ_SYSTEMP,
};

struct mrfld_adc {
        struct regmap *regmap;
        struct completion completion;
        /* Lock to protect the IPC transfers */
        struct mutex lock;
};

static irqreturn_t mrfld_adc_thread_isr(int irq, void *data)
{
        struct iio_dev *indio_dev = data;
        struct mrfld_adc *adc = iio_priv(indio_dev);

        complete(&adc->completion);
        return IRQ_HANDLED;
}

static int mrfld_adc_single_conv(struct iio_dev *indio_dev,
                                 struct iio_chan_spec const *chan,
                                 int *result)
{
        struct mrfld_adc *adc = iio_priv(indio_dev);
        struct regmap *regmap = adc->regmap;
        unsigned int req;
        long time_left;
        __be16 value;
        int ret;

        reinit_completion(&adc->completion);

        regmap_clear_bits(regmap, BCOVE_MADCIRQ, BCOVE_ADCIRQ_ALL);
        regmap_clear_bits(regmap, BCOVE_MIRQLVL1, BCOVE_LVL1_ADC);

        ret = regmap_read_poll_timeout(regmap, BCOVE_GPADCREQ, req,
                                       !(req & BCOVE_GPADCREQ_BUSY),
                                       2000, 1000000);
        if (ret)
                goto done;

        req = mrfld_adc_requests[chan->channel];
        ret = regmap_write(regmap, BCOVE_GPADCREQ, BCOVE_GPADCREQ_IRQEN | req);
        if (ret)
                goto done;

        time_left = wait_for_completion_interruptible_timeout(&adc->completion,
                                                              BCOVE_ADC_TIMEOUT);
        if (time_left < 0) {
                ret = time_left;
                goto done;
        }
        if (time_left == 0) {
                ret = -ETIMEDOUT;
                goto done;
        }

        ret = regmap_bulk_read(regmap, chan->address, &value, sizeof(value));
        if (ret)
                goto done;

        *result = be16_to_cpu(value);
        ret = IIO_VAL_INT;

done:
        regmap_update_bits(regmap, BCOVE_MIRQLVL1, BCOVE_LVL1_ADC, 0xff);
        regmap_update_bits(regmap, BCOVE_MADCIRQ, BCOVE_ADCIRQ_ALL, 0xff);

        return ret;
}

static int mrfld_adc_read_raw(struct iio_dev *indio_dev,
                              struct iio_chan_spec const *chan,
                              int *val, int *val2, long mask)
{
        struct mrfld_adc *adc = iio_priv(indio_dev);
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                mutex_lock(&adc->lock);
                ret = mrfld_adc_single_conv(indio_dev, chan, val);
                mutex_unlock(&adc->lock);
                return ret;
        default:
                return -EINVAL;
        }
}

static const struct iio_info mrfld_adc_iio_info = {
        .read_raw = &mrfld_adc_read_raw,
};

#define BCOVE_ADC_CHANNEL(_type, _channel, _datasheet_name, _address)   \
        {                                                               \
                .indexed = 1,                                           \
                .type = _type,                                          \
                .channel = _channel,                                    \
                .address = _address,                                    \
                .datasheet_name = _datasheet_name,                      \
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
        }

static const struct iio_chan_spec mrfld_adc_channels[] = {
        BCOVE_ADC_CHANNEL(IIO_VOLTAGE,    0, "CH0", 0xE9),
        BCOVE_ADC_CHANNEL(IIO_RESISTANCE, 1, "CH1", 0xEB),
        BCOVE_ADC_CHANNEL(IIO_CURRENT,    2, "CH2", 0xED),
        BCOVE_ADC_CHANNEL(IIO_TEMP,       3, "CH3", 0xCC),
        BCOVE_ADC_CHANNEL(IIO_TEMP,       4, "CH4", 0xC8),
        BCOVE_ADC_CHANNEL(IIO_TEMP,       5, "CH5", 0xCA),
        BCOVE_ADC_CHANNEL(IIO_TEMP,       6, "CH6", 0xC2),
        BCOVE_ADC_CHANNEL(IIO_TEMP,       7, "CH7", 0xC4),
        BCOVE_ADC_CHANNEL(IIO_TEMP,       8, "CH8", 0xC6),
};

static const struct iio_map iio_maps[] = {
        IIO_MAP("CH0", "bcove-battery", "VBATRSLT"),
        IIO_MAP("CH1", "bcove-battery", "BATTID"),
        IIO_MAP("CH2", "bcove-battery", "IBATRSLT"),
        IIO_MAP("CH3", "bcove-temp",    "PMICTEMP"),
        IIO_MAP("CH4", "bcove-temp",    "BATTEMP0"),
        IIO_MAP("CH5", "bcove-temp",    "BATTEMP1"),
        IIO_MAP("CH6", "bcove-temp",    "SYSTEMP0"),
        IIO_MAP("CH7", "bcove-temp",    "SYSTEMP1"),
        IIO_MAP("CH8", "bcove-temp",    "SYSTEMP2"),
        { }
};

static int mrfld_adc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct intel_soc_pmic *pmic = dev_get_drvdata(dev->parent);
        struct iio_dev *indio_dev;
        struct mrfld_adc *adc;
        int irq;
        int ret;

        indio_dev = devm_iio_device_alloc(dev, sizeof(struct mrfld_adc));
        if (!indio_dev)
                return -ENOMEM;

        adc = iio_priv(indio_dev);

        mutex_init(&adc->lock);
        init_completion(&adc->completion);
        adc->regmap = pmic->regmap;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        ret = devm_request_threaded_irq(dev, irq, NULL, mrfld_adc_thread_isr,
                                        IRQF_ONESHOT | IRQF_SHARED, pdev->name,
                                        indio_dev);
        if (ret)
                return ret;

        indio_dev->name = pdev->name;

        indio_dev->channels = mrfld_adc_channels;
        indio_dev->num_channels = ARRAY_SIZE(mrfld_adc_channels);
        indio_dev->info = &mrfld_adc_iio_info;
        indio_dev->modes = INDIO_DIRECT_MODE;

        ret = devm_iio_map_array_register(dev, indio_dev, iio_maps);
        if (ret)
                return ret;

        return devm_iio_device_register(dev, indio_dev);
}

static const struct platform_device_id mrfld_adc_id_table[] = {
        { .name = "mrfld_bcove_adc" },
        { }
};
MODULE_DEVICE_TABLE(platform, mrfld_adc_id_table);

static struct platform_driver mrfld_adc_driver = {
        .driver = {
                .name = "mrfld_bcove_adc",
        },
        .probe = mrfld_adc_probe,
        .id_table = mrfld_adc_id_table,
};
module_platform_driver(mrfld_adc_driver);

MODULE_AUTHOR("Bin Yang <bin.yang@intel.com>");
MODULE_AUTHOR("Vincent Pelletier <plr.vincent@gmail.com>");
MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
MODULE_DESCRIPTION("ADC driver for Basin Cove PMIC");
MODULE_LICENSE("GPL v2");