static int pi433_remove(struct spi_device *spi)
{
struct pi433_device *device = spi_get_drvdata(spi);
/* free GPIOs */
free_gpio(device);
/* make sure ops on existing fds can abort cleanly */
device->spi = NULL;
kthread_stop(device->tx_task_struct);
device_destroy(pi433_class, device->devt);
cdev_del(device->cdev);
pi433_free_minor(device);
kfree(device->rx_buffer);
kfree(device);
return 0;
}
/**
This method disables gpio to operate as pwm
@param gpio - sets pin number according to numbering scheme
GPIO is configured as input and all resources, allocated with the device are freed
*/
static int stop_pwm(const unsigned char gpio){
free_gpio(gpio);
process_update();
return 0;
}
static int pi433_probe(struct spi_device *spi)
{
struct pi433_device *device;
int retval;
/* setup spi parameters */
spi->mode = 0x00;
spi->bits_per_word = 8;
/*
* spi->max_speed_hz = 10000000;
* 1MHz already set by device tree overlay
*/
retval = spi_setup(spi);
if (retval) {
dev_dbg(&spi->dev, "configuration of SPI interface failed!\n");
return retval;
}
dev_dbg(&spi->dev,
"spi interface setup: mode 0x%2x, %d bits per word, %dhz max speed",
spi->mode, spi->bits_per_word, spi->max_speed_hz);
/* Ping the chip by reading the version register */
retval = spi_w8r8(spi, 0x10);
if (retval < 0)
return retval;
switch (retval) {
case 0x24:
dev_dbg(&spi->dev, "found pi433 (ver. 0x%x)", retval);
break;
default:
dev_dbg(&spi->dev, "unknown chip version: 0x%x", retval);
return -ENODEV;
}
/* Allocate driver data */
device = kzalloc(sizeof(*device), GFP_KERNEL);
if (!device)
return -ENOMEM;
/* Initialize the driver data */
device->spi = spi;
device->rx_active = false;
device->tx_active = false;
device->interrupt_rx_allowed = false;
/* init rx buffer */
device->rx_buffer = kmalloc(MAX_MSG_SIZE, GFP_KERNEL);
if (!device->rx_buffer) {
retval = -ENOMEM;
goto RX_failed;
}
/* init wait queues */
init_waitqueue_head(&device->tx_wait_queue);
init_waitqueue_head(&device->rx_wait_queue);
init_waitqueue_head(&device->fifo_wait_queue);
/* init fifo */
INIT_KFIFO(device->tx_fifo);
/* init mutexes and locks */
mutex_init(&device->tx_fifo_lock);
mutex_init(&device->rx_lock);
/* setup GPIO (including irq_handler) for the different DIOs */
retval = setup_gpio(device);
if (retval) {
dev_dbg(&spi->dev, "setup of GPIOs failed");
goto GPIO_failed;
}
/* setup the radio module */
retval = rf69_set_mode(spi, standby);
if (retval < 0)
goto minor_failed;
retval = rf69_set_data_mode(spi, DATAMODUL_MODE_PACKET);
if (retval < 0)
goto minor_failed;
retval = rf69_enable_amplifier(spi, MASK_PALEVEL_PA0);
if (retval < 0)
goto minor_failed;
retval = rf69_disable_amplifier(spi, MASK_PALEVEL_PA1);
if (retval < 0)
goto minor_failed;
retval = rf69_disable_amplifier(spi, MASK_PALEVEL_PA2);
if (retval < 0)
goto minor_failed;
retval = rf69_set_output_power_level(spi, 13);
if (retval < 0)
goto minor_failed;
retval = rf69_set_antenna_impedance(spi, fifty_ohm);
if (retval < 0)
goto minor_failed;
/* determ minor number */
retval = pi433_get_minor(device);
if (retval) {
dev_dbg(&spi->dev, "get of minor number failed");
goto minor_failed;
}
/* create device */
device->devt = MKDEV(MAJOR(pi433_dev), device->minor);
device->dev = device_create(pi433_class,
&spi->dev,
device->devt,
device,
"pi433.%d",
device->minor);
if (IS_ERR(device->dev)) {
pr_err("pi433: device register failed\n");
retval = PTR_ERR(device->dev);
goto device_create_failed;
} else {
dev_dbg(device->dev,
"created device for major %d, minor %d\n",
MAJOR(pi433_dev),
device->minor);
}
/* start tx thread */
device->tx_task_struct = kthread_run(pi433_tx_thread,
device,
"pi433.%d_tx_task",
device->minor);
if (IS_ERR(device->tx_task_struct)) {
dev_dbg(device->dev, "start of send thread failed");
retval = PTR_ERR(device->tx_task_struct);
goto send_thread_failed;
}
/* create cdev */
device->cdev = cdev_alloc();
if (!device->cdev) {
dev_dbg(device->dev, "allocation of cdev failed");
goto cdev_failed;
}
device->cdev->owner = THIS_MODULE;
cdev_init(device->cdev, &pi433_fops);
retval = cdev_add(device->cdev, device->devt, 1);
if (retval) {
dev_dbg(device->dev, "register of cdev failed");
goto del_cdev;
}
/* spi setup */
spi_set_drvdata(spi, device);
return 0;
del_cdev:
cdev_del(device->cdev);
cdev_failed:
kthread_stop(device->tx_task_struct);
send_thread_failed:
device_destroy(pi433_class, device->devt);
device_create_failed:
pi433_free_minor(device);
minor_failed:
free_gpio(device);
GPIO_failed:
kfree(device->rx_buffer);
RX_failed:
kfree(device);
return retval;
}