Linux 4.19.133

[linux/fpc-iii.git] / drivers / mfd / si476x-i2c.c

/*
 * drivers/mfd/si476x-i2c.c -- Core device driver for si476x MFD
 * device
 *
 * Copyright (C) 2012 Innovative Converged Devices(ICD)
 * Copyright (C) 2013 Andrey Smirnov
 *
 * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 */
#include <linux/module.h>

#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/i2c.h>
#include <linux/err.h>

#include <linux/mfd/si476x-core.h>

#define SI476X_MAX_IO_ERRORS            10
#define SI476X_DRIVER_RDS_FIFO_DEPTH    128

/**
 * si476x_core_config_pinmux() - pin function configuration function
 *
 * @core: Core device structure
 *
 * Configure the functions of the pins of the radio chip.
 *
 * The function returns zero in case of succes or negative error code
 * otherwise.
 */
static int si476x_core_config_pinmux(struct si476x_core *core)
{
        int err;
        dev_dbg(&core->client->dev, "Configuring pinmux\n");
        err = si476x_core_cmd_dig_audio_pin_cfg(core,
                                                core->pinmux.dclk,
                                                core->pinmux.dfs,
                                                core->pinmux.dout,
                                                core->pinmux.xout);
        if (err < 0) {
                dev_err(&core->client->dev,
                        "Failed to configure digital audio pins(err = %d)\n",
                        err);
                return err;
        }

        err = si476x_core_cmd_zif_pin_cfg(core,
                                          core->pinmux.iqclk,
                                          core->pinmux.iqfs,
                                          core->pinmux.iout,
                                          core->pinmux.qout);
        if (err < 0) {
                dev_err(&core->client->dev,
                        "Failed to configure ZIF pins(err = %d)\n",
                        err);
                return err;
        }

        err = si476x_core_cmd_ic_link_gpo_ctl_pin_cfg(core,
                                                      core->pinmux.icin,
                                                      core->pinmux.icip,
                                                      core->pinmux.icon,
                                                      core->pinmux.icop);
        if (err < 0) {
                dev_err(&core->client->dev,
                        "Failed to configure IC-Link/GPO pins(err = %d)\n",
                        err);
                return err;
        }

        err = si476x_core_cmd_ana_audio_pin_cfg(core,
                                                core->pinmux.lrout);
        if (err < 0) {
                dev_err(&core->client->dev,
                        "Failed to configure analog audio pins(err = %d)\n",
                        err);
                return err;
        }

        err = si476x_core_cmd_intb_pin_cfg(core,
                                           core->pinmux.intb,
                                           core->pinmux.a1);
        if (err < 0) {
                dev_err(&core->client->dev,
                        "Failed to configure interrupt pins(err = %d)\n",
                        err);
                return err;
        }

        return 0;
}

static inline void si476x_core_schedule_polling_work(struct si476x_core *core)
{
        schedule_delayed_work(&core->status_monitor,
                              usecs_to_jiffies(SI476X_STATUS_POLL_US));
}

/**
 * si476x_core_start() - early chip startup function
 * @core: Core device structure
 * @soft: When set, this flag forces "soft" startup, where "soft"
 * power down is the one done by sending appropriate command instead
 * of using reset pin of the tuner
 *
 * Perform required startup sequence to correctly power
 * up the chip and perform initial configuration. It does the
 * following sequence of actions:
 *       1. Claims and enables the power supplies VD and VIO1 required
 *          for I2C interface of the chip operation.
 *       2. Waits for 100us, pulls the reset line up, enables irq,
 *          waits for another 100us as it is specified by the
 *          datasheet.
 *       3. Sends 'POWER_UP' command to the device with all provided
 *          information about power-up parameters.
 *       4. Configures, pin multiplexor, disables digital audio and
 *          configures interrupt sources.
 *
 * The function returns zero in case of succes or negative error code
 * otherwise.
 */
int si476x_core_start(struct si476x_core *core, bool soft)
{
        struct i2c_client *client = core->client;
        int err;

        if (!soft) {
                if (gpio_is_valid(core->gpio_reset))
                        gpio_set_value_cansleep(core->gpio_reset, 1);

                if (client->irq)
                        enable_irq(client->irq);

                udelay(100);

                if (!client->irq) {
                        atomic_set(&core->is_alive, 1);
                        si476x_core_schedule_polling_work(core);
                }
        } else {
                if (client->irq)
                        enable_irq(client->irq);
                else {
                        atomic_set(&core->is_alive, 1);
                        si476x_core_schedule_polling_work(core);
                }
        }

        err = si476x_core_cmd_power_up(core,
                                       &core->power_up_parameters);

        if (err < 0) {
                dev_err(&core->client->dev,
                        "Power up failure(err = %d)\n",
                        err);
                goto disable_irq;
        }

        if (client->irq)
                atomic_set(&core->is_alive, 1);

        err = si476x_core_config_pinmux(core);
        if (err < 0) {
                dev_err(&core->client->dev,
                        "Failed to configure pinmux(err = %d)\n",
                        err);
                goto disable_irq;
        }

        if (client->irq) {
                err = regmap_write(core->regmap,
                                   SI476X_PROP_INT_CTL_ENABLE,
                                   SI476X_RDSIEN |
                                   SI476X_STCIEN |
                                   SI476X_CTSIEN);
                if (err < 0) {
                        dev_err(&core->client->dev,
                                "Failed to configure interrupt sources"
                                "(err = %d)\n", err);
                        goto disable_irq;
                }
        }

        return 0;

disable_irq:
        if (err == -ENODEV)
                atomic_set(&core->is_alive, 0);

        if (client->irq)
                disable_irq(client->irq);
        else
                cancel_delayed_work_sync(&core->status_monitor);

        if (gpio_is_valid(core->gpio_reset))
                gpio_set_value_cansleep(core->gpio_reset, 0);

        return err;
}
EXPORT_SYMBOL_GPL(si476x_core_start);

/**
 * si476x_core_stop() - chip power-down function
 * @core: Core device structure
 * @soft: When set, function sends a POWER_DOWN command instead of
 * bringing reset line low
 *
 * Power down the chip by performing following actions:
 * 1. Disable IRQ or stop the polling worker
 * 2. Send the POWER_DOWN command if the power down is soft or bring
 *    reset line low if not.
 *
 * The function returns zero in case of succes or negative error code
 * otherwise.
 */
int si476x_core_stop(struct si476x_core *core, bool soft)
{
        int err = 0;
        atomic_set(&core->is_alive, 0);

        if (soft) {
                /* TODO: This probably shoud be a configurable option,
                 * so it is possible to have the chips keep their
                 * oscillators running
                 */
                struct si476x_power_down_args args = {
                        .xosc = false,
                };
                err = si476x_core_cmd_power_down(core, &args);
        }

        /* We couldn't disable those before
         * 'si476x_core_cmd_power_down' since we expect to get CTS
         * interrupt */
        if (core->client->irq)
                disable_irq(core->client->irq);
        else
                cancel_delayed_work_sync(&core->status_monitor);

        if (!soft) {
                if (gpio_is_valid(core->gpio_reset))
                        gpio_set_value_cansleep(core->gpio_reset, 0);
        }
        return err;
}
EXPORT_SYMBOL_GPL(si476x_core_stop);

/**
 * si476x_core_set_power_state() - set the level at which the power is
 * supplied for the chip.
 * @core: Core device structure
 * @next_state: enum si476x_power_state describing power state to
 *              switch to.
 *
 * Switch on all the required power supplies
 *
 * This function returns 0 in case of suvccess and negative error code
 * otherwise.
 */
int si476x_core_set_power_state(struct si476x_core *core,
                                enum si476x_power_state next_state)
{
        /*
           It is not clear form the datasheet if it is possible to
           work with device if not all power domains are operational.
           So for now the power-up policy is "power-up all the things!"
         */
        int err = 0;

        if (core->power_state == SI476X_POWER_INCONSISTENT) {
                dev_err(&core->client->dev,
                        "The device in inconsistent power state\n");
                return -EINVAL;
        }

        if (next_state != core->power_state) {
                switch (next_state) {
                case SI476X_POWER_UP_FULL:
                        err = regulator_bulk_enable(ARRAY_SIZE(core->supplies),
                                                    core->supplies);
                        if (err < 0) {
                                core->power_state = SI476X_POWER_INCONSISTENT;
                                break;
                        }
                        /*
                         * Startup timing diagram recommends to have a
                         * 100 us delay between enabling of the power
                         * supplies and turning the tuner on.
                         */
                        udelay(100);

                        err = si476x_core_start(core, false);
                        if (err < 0)
                                goto disable_regulators;

                        core->power_state = next_state;
                        break;

                case SI476X_POWER_DOWN:
                        core->power_state = next_state;
                        err = si476x_core_stop(core, false);
                        if (err < 0)
                                core->power_state = SI476X_POWER_INCONSISTENT;
disable_regulators:
                        err = regulator_bulk_disable(ARRAY_SIZE(core->supplies),
                                                     core->supplies);
                        if (err < 0)
                                core->power_state = SI476X_POWER_INCONSISTENT;
                        break;
                default:
                        BUG();
                }
        }

        return err;
}
EXPORT_SYMBOL_GPL(si476x_core_set_power_state);

/**
 * si476x_core_report_drainer_stop() - mark the completion of the RDS
 * buffer drain porcess by the worker.
 *
 * @core: Core device structure
 */
static inline void si476x_core_report_drainer_stop(struct si476x_core *core)
{
        mutex_lock(&core->rds_drainer_status_lock);
        core->rds_drainer_is_working = false;
        mutex_unlock(&core->rds_drainer_status_lock);
}

/**
 * si476x_core_start_rds_drainer_once() - start RDS drainer worker if
 * ther is none working, do nothing otherwise
 *
 * @core: Datastructure corresponding to the chip.
 */
static inline void si476x_core_start_rds_drainer_once(struct si476x_core *core)
{
        mutex_lock(&core->rds_drainer_status_lock);
        if (!core->rds_drainer_is_working) {
                core->rds_drainer_is_working = true;
                schedule_work(&core->rds_fifo_drainer);
        }
        mutex_unlock(&core->rds_drainer_status_lock);
}
/**
 * si476x_drain_rds_fifo() - RDS buffer drainer.
 * @work: struct work_struct being ppassed to the function by the
 * kernel.
 *
 * Drain the contents of the RDS FIFO of
 */
static void si476x_core_drain_rds_fifo(struct work_struct *work)
{
        int err;

        struct si476x_core *core = container_of(work, struct si476x_core,
                                                rds_fifo_drainer);

        struct si476x_rds_status_report report;

        si476x_core_lock(core);
        err = si476x_core_cmd_fm_rds_status(core, true, false, false, &report);
        if (!err) {
                int i = report.rdsfifoused;
                dev_dbg(&core->client->dev,
                        "%d elements in RDS FIFO. Draining.\n", i);
                for (; i > 0; --i) {
                        err = si476x_core_cmd_fm_rds_status(core, false, false,
                                                            (i == 1), &report);
                        if (err < 0)
                                goto unlock;

                        kfifo_in(&core->rds_fifo, report.rds,
                                 sizeof(report.rds));
                        dev_dbg(&core->client->dev, "RDS data:\n %*ph\n",
                                (int)sizeof(report.rds), report.rds);
                }
                dev_dbg(&core->client->dev, "Drrrrained!\n");
                wake_up_interruptible(&core->rds_read_queue);
        }

unlock:
        si476x_core_unlock(core);
        si476x_core_report_drainer_stop(core);
}

/**
 * si476x_core_pronounce_dead()
 *
 * @core: Core device structure
 *
 * Mark the device as being dead and wake up all potentially waiting
 * threads of execution.
 *
 */
static void si476x_core_pronounce_dead(struct si476x_core *core)
{
        dev_info(&core->client->dev, "Core device is dead.\n");

        atomic_set(&core->is_alive, 0);

        /* Wake up al possible waiting processes */
        wake_up_interruptible(&core->rds_read_queue);

        atomic_set(&core->cts, 1);
        wake_up(&core->command);

        atomic_set(&core->stc, 1);
        wake_up(&core->tuning);
}

/**
 * si476x_core_i2c_xfer()
 *
 * @core: Core device structure
 * @type: Transfer type
 * @buf: Transfer buffer for/with data
 * @count: Transfer buffer size
 *
 * Perfrom and I2C transfer(either read or write) and keep a counter
 * of I/O errors. If the error counter rises above the threshold
 * pronounce device dead.
 *
 * The function returns zero on succes or negative error code on
 * failure.
 */
int si476x_core_i2c_xfer(struct si476x_core *core,
                    enum si476x_i2c_type type,
                    char *buf, int count)
{
        static int io_errors_count;
        int err;
        if (type == SI476X_I2C_SEND)
                err = i2c_master_send(core->client, buf, count);
        else
                err = i2c_master_recv(core->client, buf, count);

        if (err < 0) {
                if (io_errors_count++ > SI476X_MAX_IO_ERRORS)
                        si476x_core_pronounce_dead(core);
        } else {
                io_errors_count = 0;
        }

        return err;
}
EXPORT_SYMBOL_GPL(si476x_core_i2c_xfer);

/**
 * si476x_get_status()
 * @core: Core device structure
 *
 * Get the status byte of the core device by berforming one byte I2C
 * read.
 *
 * The function returns a status value or a negative error code on
 * error.
 */
static int si476x_core_get_status(struct si476x_core *core)
{
        u8 response;
        int err = si476x_core_i2c_xfer(core, SI476X_I2C_RECV,
                                  &response, sizeof(response));

        return (err < 0) ? err : response;
}

/**
 * si476x_get_and_signal_status() - IRQ dispatcher
 * @core: Core device structure
 *
 * Dispatch the arrived interrupt request based on the value of the
 * status byte reported by the tuner.
 *
 */
static void si476x_core_get_and_signal_status(struct si476x_core *core)
{
        int status = si476x_core_get_status(core);
        if (status < 0) {
                dev_err(&core->client->dev, "Failed to get status\n");
                return;
        }

        if (status & SI476X_CTS) {
                /* Unfortunately completions could not be used for
                 * signalling CTS since this flag cannot be cleared
                 * in status byte, and therefore once it becomes true
                 * multiple calls to 'complete' would cause the
                 * commands following the current one to be completed
                 * before they actually are */
                dev_dbg(&core->client->dev, "[interrupt] CTSINT\n");
                atomic_set(&core->cts, 1);
                wake_up(&core->command);
        }

        if (status & SI476X_FM_RDS_INT) {
                dev_dbg(&core->client->dev, "[interrupt] RDSINT\n");
                si476x_core_start_rds_drainer_once(core);
        }

        if (status & SI476X_STC_INT) {
                dev_dbg(&core->client->dev, "[interrupt] STCINT\n");
                atomic_set(&core->stc, 1);
                wake_up(&core->tuning);
        }
}

static void si476x_core_poll_loop(struct work_struct *work)
{
        struct si476x_core *core = SI476X_WORK_TO_CORE(work);

        si476x_core_get_and_signal_status(core);

        if (atomic_read(&core->is_alive))
                si476x_core_schedule_polling_work(core);
}

static irqreturn_t si476x_core_interrupt(int irq, void *dev)
{
        struct si476x_core *core = dev;

        si476x_core_get_and_signal_status(core);

        return IRQ_HANDLED;
}

/**
 * si476x_firmware_version_to_revision()
 * @core: Core device structure
 * @major:  Firmware major number
 * @minor1: Firmware first minor number
 * @minor2: Firmware second minor number
 *
 * Convert a chip's firmware version number into an offset that later
 * will be used to as offset in "vtable" of tuner functions
 *
 * This function returns a positive offset in case of success and a -1
 * in case of failure.
 */
static int si476x_core_fwver_to_revision(struct si476x_core *core,
                                         int func, int major,
                                         int minor1, int minor2)
{
        switch (func) {
        case SI476X_FUNC_FM_RECEIVER:
                switch (major) {
                case 5:
                        return SI476X_REVISION_A10;
                case 8:
                        return SI476X_REVISION_A20;
                case 10:
                        return SI476X_REVISION_A30;
                default:
                        goto unknown_revision;
                }
        case SI476X_FUNC_AM_RECEIVER:
                switch (major) {
                case 5:
                        return SI476X_REVISION_A10;
                case 7:
                        return SI476X_REVISION_A20;
                case 9:
                        return SI476X_REVISION_A30;
                default:
                        goto unknown_revision;
                }
        case SI476X_FUNC_WB_RECEIVER:
                switch (major) {
                case 3:
                        return SI476X_REVISION_A10;
                case 5:
                        return SI476X_REVISION_A20;
                case 7:
                        return SI476X_REVISION_A30;
                default:
                        goto unknown_revision;
                }
        case SI476X_FUNC_BOOTLOADER:
        default:                /* FALLTHROUG */
                BUG();
                return -1;
        }

unknown_revision:
        dev_err(&core->client->dev,
                "Unsupported version of the firmware: %d.%d.%d, "
                "reverting to A10 compatible functions\n",
                major, minor1, minor2);

        return SI476X_REVISION_A10;
}

/**
 * si476x_get_revision_info()
 * @core: Core device structure
 *
 * Get the firmware version number of the device. It is done in
 * following three steps:
 *    1. Power-up the device
 *    2. Send the 'FUNC_INFO' command
 *    3. Powering the device down.
 *
 * The function return zero on success and a negative error code on
 * failure.
 */
static int si476x_core_get_revision_info(struct si476x_core *core)
{
        int rval;
        struct si476x_func_info info;

        si476x_core_lock(core);
        rval = si476x_core_set_power_state(core, SI476X_POWER_UP_FULL);
        if (rval < 0)
                goto exit;

        rval = si476x_core_cmd_func_info(core, &info);
        if (rval < 0)
                goto power_down;

        core->revision = si476x_core_fwver_to_revision(core, info.func,
                                                       info.firmware.major,
                                                       info.firmware.minor[0],
                                                       info.firmware.minor[1]);
power_down:
        si476x_core_set_power_state(core, SI476X_POWER_DOWN);
exit:
        si476x_core_unlock(core);

        return rval;
}

bool si476x_core_has_am(struct si476x_core *core)
{
        return core->chip_id == SI476X_CHIP_SI4761 ||
                core->chip_id == SI476X_CHIP_SI4764;
}
EXPORT_SYMBOL_GPL(si476x_core_has_am);

bool si476x_core_has_diversity(struct si476x_core *core)
{
        return core->chip_id == SI476X_CHIP_SI4764;
}
EXPORT_SYMBOL_GPL(si476x_core_has_diversity);

bool si476x_core_is_a_secondary_tuner(struct si476x_core *core)
{
        return si476x_core_has_diversity(core) &&
                (core->diversity_mode == SI476X_PHDIV_SECONDARY_ANTENNA ||
                 core->diversity_mode == SI476X_PHDIV_SECONDARY_COMBINING);
}
EXPORT_SYMBOL_GPL(si476x_core_is_a_secondary_tuner);

bool si476x_core_is_a_primary_tuner(struct si476x_core *core)
{
        return si476x_core_has_diversity(core) &&
                (core->diversity_mode == SI476X_PHDIV_PRIMARY_ANTENNA ||
                 core->diversity_mode == SI476X_PHDIV_PRIMARY_COMBINING);
}
EXPORT_SYMBOL_GPL(si476x_core_is_a_primary_tuner);

bool si476x_core_is_in_am_receiver_mode(struct si476x_core *core)
{
        return si476x_core_has_am(core) &&
                (core->power_up_parameters.func == SI476X_FUNC_AM_RECEIVER);
}
EXPORT_SYMBOL_GPL(si476x_core_is_in_am_receiver_mode);

bool si476x_core_is_powered_up(struct si476x_core *core)
{
        return core->power_state == SI476X_POWER_UP_FULL;
}
EXPORT_SYMBOL_GPL(si476x_core_is_powered_up);

static int si476x_core_probe(struct i2c_client *client,
                             const struct i2c_device_id *id)
{
        int rval;
        struct si476x_core          *core;
        struct si476x_platform_data *pdata;
        struct mfd_cell *cell;
        int              cell_num;

        core = devm_kzalloc(&client->dev, sizeof(*core), GFP_KERNEL);
        if (!core)
                return -ENOMEM;

        core->client = client;

        core->regmap = devm_regmap_init_si476x(core);
        if (IS_ERR(core->regmap)) {
                rval = PTR_ERR(core->regmap);
                dev_err(&client->dev,
                        "Failed to allocate register map: %d\n",
                        rval);
                return rval;
        }

        i2c_set_clientdata(client, core);

        atomic_set(&core->is_alive, 0);
        core->power_state = SI476X_POWER_DOWN;

        pdata = dev_get_platdata(&client->dev);
        if (pdata) {
                memcpy(&core->power_up_parameters,
                       &pdata->power_up_parameters,
                       sizeof(core->power_up_parameters));

                core->gpio_reset = -1;
                if (gpio_is_valid(pdata->gpio_reset)) {
                        rval = gpio_request(pdata->gpio_reset, "si476x reset");
                        if (rval) {
                                dev_err(&client->dev,
                                        "Failed to request gpio: %d\n", rval);
                                return rval;
                        }
                        core->gpio_reset = pdata->gpio_reset;
                        gpio_direction_output(core->gpio_reset, 0);
                }

                core->diversity_mode = pdata->diversity_mode;
                memcpy(&core->pinmux, &pdata->pinmux,
                       sizeof(struct si476x_pinmux));
        } else {
                dev_err(&client->dev, "No platform data provided\n");
                return -EINVAL;
        }

        core->supplies[0].supply = "vd";
        core->supplies[1].supply = "va";
        core->supplies[2].supply = "vio1";
        core->supplies[3].supply = "vio2";

        rval = devm_regulator_bulk_get(&client->dev,
                                       ARRAY_SIZE(core->supplies),
                                       core->supplies);
        if (rval) {
                dev_err(&client->dev, "Failed to get all of the regulators\n");
                goto free_gpio;
        }

        mutex_init(&core->cmd_lock);
        init_waitqueue_head(&core->command);
        init_waitqueue_head(&core->tuning);

        rval = kfifo_alloc(&core->rds_fifo,
                           SI476X_DRIVER_RDS_FIFO_DEPTH *
                           sizeof(struct v4l2_rds_data),
                           GFP_KERNEL);
        if (rval) {
                dev_err(&client->dev, "Could not allocate the FIFO\n");
                goto free_gpio;
        }
        mutex_init(&core->rds_drainer_status_lock);
        init_waitqueue_head(&core->rds_read_queue);
        INIT_WORK(&core->rds_fifo_drainer, si476x_core_drain_rds_fifo);

        if (client->irq) {
                rval = devm_request_threaded_irq(&client->dev,
                                                 client->irq, NULL,
                                                 si476x_core_interrupt,
                                                 IRQF_TRIGGER_FALLING |
                                                 IRQF_ONESHOT,
                                                 client->name, core);
                if (rval < 0) {
                        dev_err(&client->dev, "Could not request IRQ %d\n",
                                client->irq);
                        goto free_kfifo;
                }
                disable_irq(client->irq);
                dev_dbg(&client->dev, "IRQ requested.\n");

                core->rds_fifo_depth = 20;
        } else {
                INIT_DELAYED_WORK(&core->status_monitor,
                                  si476x_core_poll_loop);
                dev_info(&client->dev,
                         "No IRQ number specified, will use polling\n");

                core->rds_fifo_depth = 5;
        }

        core->chip_id = id->driver_data;

        rval = si476x_core_get_revision_info(core);
        if (rval < 0) {
                rval = -ENODEV;
                goto free_kfifo;
        }

        cell_num = 0;

        cell = &core->cells[SI476X_RADIO_CELL];
        cell->name = "si476x-radio";
        cell_num++;

#ifdef CONFIG_SND_SOC_SI476X
        if ((core->chip_id == SI476X_CHIP_SI4761 ||
             core->chip_id == SI476X_CHIP_SI4764)       &&
            core->pinmux.dclk == SI476X_DCLK_DAUDIO     &&
            core->pinmux.dfs  == SI476X_DFS_DAUDIO      &&
            core->pinmux.dout == SI476X_DOUT_I2S_OUTPUT &&
            core->pinmux.xout == SI476X_XOUT_TRISTATE) {
                cell = &core->cells[SI476X_CODEC_CELL];
                cell->name          = "si476x-codec";
                cell_num++;
        }
#endif
        rval = mfd_add_devices(&client->dev,
                               (client->adapter->nr << 8) + client->addr,
                               core->cells, cell_num,
                               NULL, 0, NULL);
        if (!rval)
                return 0;

free_kfifo:
        kfifo_free(&core->rds_fifo);

free_gpio:
        if (gpio_is_valid(core->gpio_reset))
                gpio_free(core->gpio_reset);

        return rval;
}

static int si476x_core_remove(struct i2c_client *client)
{
        struct si476x_core *core = i2c_get_clientdata(client);

        si476x_core_pronounce_dead(core);
        mfd_remove_devices(&client->dev);

        if (client->irq)
                disable_irq(client->irq);
        else
                cancel_delayed_work_sync(&core->status_monitor);

        kfifo_free(&core->rds_fifo);

        if (gpio_is_valid(core->gpio_reset))
                gpio_free(core->gpio_reset);

        return 0;
}


static const struct i2c_device_id si476x_id[] = {
        { "si4761", SI476X_CHIP_SI4761 },
        { "si4764", SI476X_CHIP_SI4764 },
        { "si4768", SI476X_CHIP_SI4768 },
        { },
};
MODULE_DEVICE_TABLE(i2c, si476x_id);

static struct i2c_driver si476x_core_driver = {
        .driver         = {
                .name   = "si476x-core",
        },
        .probe          = si476x_core_probe,
        .remove         = si476x_core_remove,
        .id_table       = si476x_id,
};
module_i2c_driver(si476x_core_driver);


MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
MODULE_DESCRIPTION("Si4761/64/68 AM/FM MFD core device driver");
MODULE_LICENSE("GPL");