[media] mfd: Add the main bulk of core driver for SI476x code (b40fe4f6) · Commits · e / devices / android_kernel_sony_msm8998

drivers/mfd/si476x-i2c.c

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+886 −0

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		/*
		* 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",
		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 comptible 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) {
		dev_err(&client->dev,
		"failed to allocate 'struct si476x_core'\n");
		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 = client->dev.platform_data;
		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, "Failet to gett 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 alloate 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,
		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",
		.owner = THIS_MODULE,
		},
		.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");