https://github.com/torvalds/linux
Tip revision: af42d3466bdc8f39806b26f593604fdc54140bcb authored by Linus Torvalds on 17 November 2019, 22:47:30 UTC
Linux 5.4-rc8
Linux 5.4-rc8
Tip revision: af42d34
radio-si470x-i2c.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* drivers/media/radio/si470x/radio-si470x-i2c.c
*
* I2C driver for radios with Silicon Labs Si470x FM Radio Receivers
*
* Copyright (c) 2009 Samsung Electronics Co.Ltd
* Author: Joonyoung Shim <jy0922.shim@samsung.com>
*/
/* driver definitions */
#define DRIVER_AUTHOR "Joonyoung Shim <jy0922.shim@samsung.com>";
#define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
#define DRIVER_DESC "I2C radio driver for Si470x FM Radio Receivers"
#define DRIVER_VERSION "1.0.2"
/* kernel includes */
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include "radio-si470x.h"
/* I2C Device ID List */
static const struct i2c_device_id si470x_i2c_id[] = {
/* Generic Entry */
{ "si470x", 0 },
/* Terminating entry */
{ }
};
MODULE_DEVICE_TABLE(i2c, si470x_i2c_id);
/**************************************************************************
* Module Parameters
**************************************************************************/
/* Radio Nr */
static int radio_nr = -1;
module_param(radio_nr, int, 0444);
MODULE_PARM_DESC(radio_nr, "Radio Nr");
/* RDS buffer blocks */
static unsigned int rds_buf = 100;
module_param(rds_buf, uint, 0444);
MODULE_PARM_DESC(rds_buf, "RDS buffer entries: *100*");
/* RDS maximum block errors */
static unsigned short max_rds_errors = 1;
/* 0 means 0 errors requiring correction */
/* 1 means 1-2 errors requiring correction (used by original USBRadio.exe) */
/* 2 means 3-5 errors requiring correction */
/* 3 means 6+ errors or errors in checkword, correction not possible */
module_param(max_rds_errors, ushort, 0644);
MODULE_PARM_DESC(max_rds_errors, "RDS maximum block errors: *1*");
/**************************************************************************
* I2C Definitions
**************************************************************************/
/* Write starts with the upper byte of register 0x02 */
#define WRITE_REG_NUM 8
#define WRITE_INDEX(i) (i + 0x02)
/* Read starts with the upper byte of register 0x0a */
#define READ_REG_NUM RADIO_REGISTER_NUM
#define READ_INDEX(i) ((i + RADIO_REGISTER_NUM - 0x0a) % READ_REG_NUM)
/**************************************************************************
* General Driver Functions - REGISTERs
**************************************************************************/
/*
* si470x_get_register - read register
*/
static int si470x_get_register(struct si470x_device *radio, int regnr)
{
__be16 buf[READ_REG_NUM];
struct i2c_msg msgs[1] = {
{
.addr = radio->client->addr,
.flags = I2C_M_RD,
.len = sizeof(u16) * READ_REG_NUM,
.buf = (void *)buf
},
};
if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
return -EIO;
radio->registers[regnr] = __be16_to_cpu(buf[READ_INDEX(regnr)]);
return 0;
}
/*
* si470x_set_register - write register
*/
static int si470x_set_register(struct si470x_device *radio, int regnr)
{
int i;
__be16 buf[WRITE_REG_NUM];
struct i2c_msg msgs[1] = {
{
.addr = radio->client->addr,
.len = sizeof(u16) * WRITE_REG_NUM,
.buf = (void *)buf
},
};
for (i = 0; i < WRITE_REG_NUM; i++)
buf[i] = __cpu_to_be16(radio->registers[WRITE_INDEX(i)]);
if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
return -EIO;
return 0;
}
/**************************************************************************
* General Driver Functions - ENTIRE REGISTERS
**************************************************************************/
/*
* si470x_get_all_registers - read entire registers
*/
static int si470x_get_all_registers(struct si470x_device *radio)
{
int i;
__be16 buf[READ_REG_NUM];
struct i2c_msg msgs[1] = {
{
.addr = radio->client->addr,
.flags = I2C_M_RD,
.len = sizeof(u16) * READ_REG_NUM,
.buf = (void *)buf
},
};
if (i2c_transfer(radio->client->adapter, msgs, 1) != 1)
return -EIO;
for (i = 0; i < READ_REG_NUM; i++)
radio->registers[i] = __be16_to_cpu(buf[READ_INDEX(i)]);
return 0;
}
/**************************************************************************
* File Operations Interface
**************************************************************************/
/*
* si470x_fops_open - file open
*/
static int si470x_fops_open(struct file *file)
{
struct si470x_device *radio = video_drvdata(file);
int retval = v4l2_fh_open(file);
if (retval)
return retval;
if (v4l2_fh_is_singular_file(file)) {
/* start radio */
retval = si470x_start(radio);
if (retval < 0)
goto done;
/* enable RDS / STC interrupt */
radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDSIEN;
radio->registers[SYSCONFIG1] |= SYSCONFIG1_STCIEN;
radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_GPIO2;
radio->registers[SYSCONFIG1] |= 0x1 << 2;
retval = si470x_set_register(radio, SYSCONFIG1);
}
done:
if (retval)
v4l2_fh_release(file);
return retval;
}
/*
* si470x_fops_release - file release
*/
static int si470x_fops_release(struct file *file)
{
struct si470x_device *radio = video_drvdata(file);
if (v4l2_fh_is_singular_file(file))
/* stop radio */
si470x_stop(radio);
return v4l2_fh_release(file);
}
/**************************************************************************
* Video4Linux Interface
**************************************************************************/
/*
* si470x_vidioc_querycap - query device capabilities
*/
static int si470x_vidioc_querycap(struct file *file, void *priv,
struct v4l2_capability *capability)
{
strscpy(capability->driver, DRIVER_NAME, sizeof(capability->driver));
strscpy(capability->card, DRIVER_CARD, sizeof(capability->card));
return 0;
}
/**************************************************************************
* I2C Interface
**************************************************************************/
/*
* si470x_i2c_interrupt - interrupt handler
*/
static irqreturn_t si470x_i2c_interrupt(int irq, void *dev_id)
{
struct si470x_device *radio = dev_id;
unsigned char regnr;
unsigned char blocknum;
unsigned short bler; /* rds block errors */
unsigned short rds;
unsigned char tmpbuf[3];
int retval = 0;
/* check Seek/Tune Complete */
retval = si470x_get_register(radio, STATUSRSSI);
if (retval < 0)
goto end;
if (radio->registers[STATUSRSSI] & STATUSRSSI_STC)
complete(&radio->completion);
/* safety checks */
if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
goto end;
/* Update RDS registers */
for (regnr = 1; regnr < RDS_REGISTER_NUM; regnr++) {
retval = si470x_get_register(radio, STATUSRSSI + regnr);
if (retval < 0)
goto end;
}
/* get rds blocks */
if ((radio->registers[STATUSRSSI] & STATUSRSSI_RDSR) == 0)
/* No RDS group ready, better luck next time */
goto end;
for (blocknum = 0; blocknum < 4; blocknum++) {
switch (blocknum) {
default:
bler = (radio->registers[STATUSRSSI] &
STATUSRSSI_BLERA) >> 9;
rds = radio->registers[RDSA];
break;
case 1:
bler = (radio->registers[READCHAN] &
READCHAN_BLERB) >> 14;
rds = radio->registers[RDSB];
break;
case 2:
bler = (radio->registers[READCHAN] &
READCHAN_BLERC) >> 12;
rds = radio->registers[RDSC];
break;
case 3:
bler = (radio->registers[READCHAN] &
READCHAN_BLERD) >> 10;
rds = radio->registers[RDSD];
break;
}
/* Fill the V4L2 RDS buffer */
put_unaligned_le16(rds, &tmpbuf);
tmpbuf[2] = blocknum; /* offset name */
tmpbuf[2] |= blocknum << 3; /* received offset */
if (bler > max_rds_errors)
tmpbuf[2] |= 0x80; /* uncorrectable errors */
else if (bler > 0)
tmpbuf[2] |= 0x40; /* corrected error(s) */
/* copy RDS block to internal buffer */
memcpy(&radio->buffer[radio->wr_index], &tmpbuf, 3);
radio->wr_index += 3;
/* wrap write pointer */
if (radio->wr_index >= radio->buf_size)
radio->wr_index = 0;
/* check for overflow */
if (radio->wr_index == radio->rd_index) {
/* increment and wrap read pointer */
radio->rd_index += 3;
if (radio->rd_index >= radio->buf_size)
radio->rd_index = 0;
}
}
if (radio->wr_index != radio->rd_index)
wake_up_interruptible(&radio->read_queue);
end:
return IRQ_HANDLED;
}
/*
* si470x_i2c_probe - probe for the device
*/
static int si470x_i2c_probe(struct i2c_client *client)
{
struct si470x_device *radio;
int retval = 0;
unsigned char version_warning = 0;
/* private data allocation and initialization */
radio = devm_kzalloc(&client->dev, sizeof(*radio), GFP_KERNEL);
if (!radio) {
retval = -ENOMEM;
goto err_initial;
}
radio->client = client;
radio->band = 1; /* Default to 76 - 108 MHz */
mutex_init(&radio->lock);
init_completion(&radio->completion);
radio->get_register = si470x_get_register;
radio->set_register = si470x_set_register;
radio->fops_open = si470x_fops_open;
radio->fops_release = si470x_fops_release;
radio->vidioc_querycap = si470x_vidioc_querycap;
retval = v4l2_device_register(&client->dev, &radio->v4l2_dev);
if (retval < 0) {
dev_err(&client->dev, "couldn't register v4l2_device\n");
goto err_initial;
}
v4l2_ctrl_handler_init(&radio->hdl, 2);
v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
V4L2_CID_AUDIO_MUTE, 0, 1, 1, 1);
v4l2_ctrl_new_std(&radio->hdl, &si470x_ctrl_ops,
V4L2_CID_AUDIO_VOLUME, 0, 15, 1, 15);
if (radio->hdl.error) {
retval = radio->hdl.error;
dev_err(&client->dev, "couldn't register control\n");
goto err_dev;
}
/* video device initialization */
radio->videodev = si470x_viddev_template;
radio->videodev.ctrl_handler = &radio->hdl;
radio->videodev.lock = &radio->lock;
radio->videodev.v4l2_dev = &radio->v4l2_dev;
radio->videodev.release = video_device_release_empty;
radio->videodev.device_caps =
V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE | V4L2_CAP_TUNER |
V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE;
video_set_drvdata(&radio->videodev, radio);
radio->gpio_reset = devm_gpiod_get_optional(&client->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(radio->gpio_reset)) {
retval = PTR_ERR(radio->gpio_reset);
dev_err(&client->dev, "Failed to request gpio: %d\n", retval);
goto err_all;
}
if (radio->gpio_reset)
gpiod_set_value(radio->gpio_reset, 1);
/* power up : need 110ms */
radio->registers[POWERCFG] = POWERCFG_ENABLE;
if (si470x_set_register(radio, POWERCFG) < 0) {
retval = -EIO;
goto err_all;
}
msleep(110);
/* get device and chip versions */
if (si470x_get_all_registers(radio) < 0) {
retval = -EIO;
goto err_all;
}
dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n",
radio->registers[DEVICEID], radio->registers[SI_CHIPID]);
if ((radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE) < RADIO_FW_VERSION) {
dev_warn(&client->dev,
"This driver is known to work with firmware version %hu,\n",
RADIO_FW_VERSION);
dev_warn(&client->dev,
"but the device has firmware version %hu.\n",
radio->registers[SI_CHIPID] & SI_CHIPID_FIRMWARE);
version_warning = 1;
}
/* give out version warning */
if (version_warning == 1) {
dev_warn(&client->dev,
"If you have some trouble using this driver,\n");
dev_warn(&client->dev,
"please report to V4L ML at linux-media@vger.kernel.org\n");
}
/* set initial frequency */
si470x_set_freq(radio, 87.5 * FREQ_MUL); /* available in all regions */
/* rds buffer allocation */
radio->buf_size = rds_buf * 3;
radio->buffer = devm_kmalloc(&client->dev, radio->buf_size, GFP_KERNEL);
if (!radio->buffer) {
retval = -EIO;
goto err_all;
}
/* rds buffer configuration */
radio->wr_index = 0;
radio->rd_index = 0;
init_waitqueue_head(&radio->read_queue);
retval = devm_request_threaded_irq(&client->dev, client->irq, NULL,
si470x_i2c_interrupt,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
DRIVER_NAME, radio);
if (retval) {
dev_err(&client->dev, "Failed to register interrupt\n");
goto err_all;
}
/* register video device */
retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
radio_nr);
if (retval) {
dev_warn(&client->dev, "Could not register video device\n");
goto err_all;
}
i2c_set_clientdata(client, radio);
return 0;
err_all:
v4l2_ctrl_handler_free(&radio->hdl);
err_dev:
v4l2_device_unregister(&radio->v4l2_dev);
err_initial:
return retval;
}
/*
* si470x_i2c_remove - remove the device
*/
static int si470x_i2c_remove(struct i2c_client *client)
{
struct si470x_device *radio = i2c_get_clientdata(client);
video_unregister_device(&radio->videodev);
if (radio->gpio_reset)
gpiod_set_value(radio->gpio_reset, 0);
return 0;
}
#ifdef CONFIG_PM_SLEEP
/*
* si470x_i2c_suspend - suspend the device
*/
static int si470x_i2c_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct si470x_device *radio = i2c_get_clientdata(client);
/* power down */
radio->registers[POWERCFG] |= POWERCFG_DISABLE;
if (si470x_set_register(radio, POWERCFG) < 0)
return -EIO;
return 0;
}
/*
* si470x_i2c_resume - resume the device
*/
static int si470x_i2c_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct si470x_device *radio = i2c_get_clientdata(client);
/* power up : need 110ms */
radio->registers[POWERCFG] |= POWERCFG_ENABLE;
if (si470x_set_register(radio, POWERCFG) < 0)
return -EIO;
msleep(110);
return 0;
}
static SIMPLE_DEV_PM_OPS(si470x_i2c_pm, si470x_i2c_suspend, si470x_i2c_resume);
#endif
#if IS_ENABLED(CONFIG_OF)
static const struct of_device_id si470x_of_match[] = {
{ .compatible = "silabs,si470x" },
{ },
};
MODULE_DEVICE_TABLE(of, si470x_of_match);
#endif
/*
* si470x_i2c_driver - i2c driver interface
*/
static struct i2c_driver si470x_i2c_driver = {
.driver = {
.name = "si470x",
.of_match_table = of_match_ptr(si470x_of_match),
#ifdef CONFIG_PM_SLEEP
.pm = &si470x_i2c_pm,
#endif
},
.probe_new = si470x_i2c_probe,
.remove = si470x_i2c_remove,
.id_table = si470x_i2c_id,
};
module_i2c_driver(si470x_i2c_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_VERSION(DRIVER_VERSION);