diff options
Diffstat (limited to 'drivers/media/radio/si470x/radio-si470x-i2c.c')
| -rw-r--r-- | drivers/media/radio/si470x/radio-si470x-i2c.c | 526 |
1 files changed, 526 insertions, 0 deletions
diff --git a/drivers/media/radio/si470x/radio-si470x-i2c.c b/drivers/media/radio/si470x/radio-si470x-i2c.c new file mode 100644 index 0000000..e5fc9ac --- /dev/null +++ b/drivers/media/radio/si470x/radio-si470x-i2c.c @@ -0,0 +1,526 @@ +/* + * 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> + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + + +/* 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/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 + */ +int si470x_get_register(struct si470x_device *radio, int regnr) +{ + u16 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 + */ +int si470x_set_register(struct si470x_device *radio, int regnr) +{ + int i; + u16 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; + u16 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 + */ +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 + */ +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 + */ +int si470x_vidioc_querycap(struct file *file, void *priv, + struct v4l2_capability *capability) +{ + strlcpy(capability->driver, DRIVER_NAME, sizeof(capability->driver)); + strlcpy(capability->card, DRIVER_CARD, sizeof(capability->card)); + capability->device_caps = V4L2_CAP_HW_FREQ_SEEK | V4L2_CAP_READWRITE | + V4L2_CAP_TUNER | V4L2_CAP_RADIO | V4L2_CAP_RDS_CAPTURE; + capability->capabilities = capability->device_caps | V4L2_CAP_DEVICE_CAPS; + + 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, + const struct i2c_device_id *id) +{ + struct si470x_device *radio; + int retval = 0; + unsigned char version_warning = 0; + + /* private data allocation and initialization */ + radio = kzalloc(sizeof(struct si470x_device), 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); + + /* video device initialization */ + radio->videodev = si470x_viddev_template; + video_set_drvdata(&radio->videodev, radio); + + /* power up : need 110ms */ + radio->registers[POWERCFG] = POWERCFG_ENABLE; + if (si470x_set_register(radio, POWERCFG) < 0) { + retval = -EIO; + goto err_radio; + } + msleep(110); + + /* get device and chip versions */ + if (si470x_get_all_registers(radio) < 0) { + retval = -EIO; + goto err_radio; + } + dev_info(&client->dev, "DeviceID=0x%4.4hx ChipID=0x%4.4hx\n", + radio->registers[DEVICEID], radio->registers[CHIPID]); + if ((radio->registers[CHIPID] & 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[CHIPID] & 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 = kmalloc(radio->buf_size, GFP_KERNEL); + if (!radio->buffer) { + retval = -EIO; + goto err_radio; + } + + /* rds buffer configuration */ + radio->wr_index = 0; + radio->rd_index = 0; + init_waitqueue_head(&radio->read_queue); + + retval = request_threaded_irq(client->irq, NULL, si470x_i2c_interrupt, + IRQF_TRIGGER_FALLING, DRIVER_NAME, radio); + if (retval) { + dev_err(&client->dev, "Failed to register interrupt\n"); + goto err_rds; + } + + /* 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: + free_irq(client->irq, radio); +err_rds: + kfree(radio->buffer); +err_radio: + kfree(radio); +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); + + free_irq(client->irq, radio); + video_unregister_device(&radio->videodev); + kfree(radio); + + return 0; +} + + +#ifdef CONFIG_PM +/* + * 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 + + +/* + * si470x_i2c_driver - i2c driver interface + */ +static struct i2c_driver si470x_i2c_driver = { + .driver = { + .name = "si470x", + .owner = THIS_MODULE, +#ifdef CONFIG_PM + .pm = &si470x_i2c_pm, +#endif + }, + .probe = 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); |