- 根目录:
- 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 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 = 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, "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");