diff options
Diffstat (limited to 'drivers/staging/pi433/pi433_if.c')
| -rw-r--r-- | drivers/staging/pi433/pi433_if.c | 1338 |
1 files changed, 1338 insertions, 0 deletions
diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c new file mode 100644 index 000000000000..93c01680f016 --- /dev/null +++ b/drivers/staging/pi433/pi433_if.c @@ -0,0 +1,1338 @@ +/* + * userspace interface for pi433 radio module + * + * Pi433 is a 433MHz radio module for the Raspberry Pi. + * It is based on the HopeRf Module RFM69CW. Therefore inside of this + * driver, you'll find an abstraction of the rf69 chip. + * + * If needed, this driver could be extended, to also support other + * devices, basing on HopeRfs rf69. + * + * The driver can also be extended, to support other modules of + * HopeRf with a similar interace - e. g. RFM69HCW, RFM12, RFM95, ... + * + * Copyright (C) 2016 Wolf-Entwicklungen + * Marcus Wolf <linux@wolf-entwicklungen.de> + * + * 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. + */ + +#undef DEBUG + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/idr.h> +#include <linux/ioctl.h> +#include <linux/uaccess.h> +#include <linux/fs.h> +#include <linux/device.h> +#include <linux/cdev.h> +#include <linux/err.h> +#include <linux/kfifo.h> +#include <linux/errno.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/gpio/consumer.h> +#include <linux/kthread.h> +#include <linux/wait.h> +#include <linux/spi/spi.h> +#ifdef CONFIG_COMPAT +#include <asm/compat.h> +#endif + +#include "pi433_if.h" +#include "rf69.h" + + +#define N_PI433_MINORS (1U << MINORBITS) /*32*/ /* ... up to 256 */ +#define MAX_MSG_SIZE 900 /* min: FIFO_SIZE! */ +#define MSG_FIFO_SIZE 65536 /* 65536 = 2^16 */ +#define NUM_DIO 2 + +static dev_t pi433_dev; +static DEFINE_IDR(pi433_idr); +static DEFINE_MUTEX(minor_lock); /* Protect idr accesses */ + +static struct class *pi433_class; /* mainly for udev to create /dev/pi433 */ + +/* tx config is instance specific + * so with each open a new tx config struct is needed + */ +/* rx config is device specific + * so we have just one rx config, ebedded in device struct + */ +struct pi433_device { + /* device handling related values */ + dev_t devt; + int minor; + struct device *dev; + struct cdev *cdev; + struct spi_device *spi; + unsigned users; + + /* irq related values */ + struct gpio_desc *gpiod[NUM_DIO]; + int irq_num[NUM_DIO]; + u8 irq_state[NUM_DIO]; + + /* tx related values */ + STRUCT_KFIFO_REC_1(MSG_FIFO_SIZE) tx_fifo; + struct mutex tx_fifo_lock; // TODO: check, whether necessary or obsolete + struct task_struct *tx_task_struct; + wait_queue_head_t tx_wait_queue; + u8 free_in_fifo; + char buffer[MAX_MSG_SIZE]; + + /* rx related values */ + struct pi433_rx_cfg rx_cfg; + u8 *rx_buffer; + unsigned int rx_buffer_size; + u32 rx_bytes_to_drop; + u32 rx_bytes_dropped; + unsigned int rx_position; + struct mutex rx_lock; + wait_queue_head_t rx_wait_queue; + + /* fifo wait queue */ + struct task_struct *fifo_task_struct; + wait_queue_head_t fifo_wait_queue; + + /* flags */ + bool rx_active; + bool tx_active; + bool interrupt_rx_allowed; +}; + +struct pi433_instance { + struct pi433_device *device; + struct pi433_tx_cfg tx_cfg; +}; + +/*-------------------------------------------------------------------------*/ + +/* macro for checked access of registers of radio module */ +#define SET_CHECKED(retval) \ + if (retval < 0) \ + return retval; + +/*-------------------------------------------------------------------------*/ + +/* GPIO interrupt handlers */ +static irqreturn_t DIO0_irq_handler(int irq, void *dev_id) +{ + struct pi433_device *device = dev_id; + + if (device->irq_state[DIO0] == DIO_PacketSent) + { + device->free_in_fifo = FIFO_SIZE; + printk("DIO0 irq: Packet sent\n"); // TODO: printk() should include KERN_ facility level + wake_up_interruptible(&device->fifo_wait_queue); + } + else if (device->irq_state[DIO0] == DIO_Rssi_DIO0) + { + printk("DIO0 irq: RSSI level over threshold\n"); + wake_up_interruptible(&device->rx_wait_queue); + } + else if (device->irq_state[DIO0] == DIO_PayloadReady) + { + printk("DIO0 irq: PayloadReady\n"); + device->free_in_fifo = 0; + wake_up_interruptible(&device->fifo_wait_queue); + } + + return IRQ_HANDLED; +} + +static irqreturn_t DIO1_irq_handler(int irq, void *dev_id) +{ + struct pi433_device *device = dev_id; + + if (device->irq_state[DIO1] == DIO_FifoNotEmpty_DIO1) + { + device->free_in_fifo = FIFO_SIZE; + } + else if (device->irq_state[DIO1] == DIO_FifoLevel) + { + if (device->rx_active) device->free_in_fifo = FIFO_THRESHOLD - 1; + else device->free_in_fifo = FIFO_SIZE - FIFO_THRESHOLD - 1; + } + printk("DIO1 irq: %d bytes free in fifo\n", device->free_in_fifo); // TODO: printk() should include KERN_ facility level + wake_up_interruptible(&device->fifo_wait_queue); + + return IRQ_HANDLED; +} + +/*-------------------------------------------------------------------------*/ + +static int +rf69_set_rx_cfg(struct pi433_device *dev, struct pi433_rx_cfg *rx_cfg) +{ + int ret; + int payload_length; + + /* receiver config */ + SET_CHECKED(rf69_set_frequency (dev->spi, rx_cfg->frequency)); + SET_CHECKED(rf69_set_bit_rate (dev->spi, rx_cfg->bit_rate)); + SET_CHECKED(rf69_set_modulation (dev->spi, rx_cfg->modulation)); + SET_CHECKED(rf69_set_antenna_impedance (dev->spi, rx_cfg->antenna_impedance)); + SET_CHECKED(rf69_set_rssi_threshold (dev->spi, rx_cfg->rssi_threshold)); + SET_CHECKED(rf69_set_ook_threshold_dec (dev->spi, rx_cfg->thresholdDecrement)); + SET_CHECKED(rf69_set_bandwidth (dev->spi, rx_cfg->bw_mantisse, rx_cfg->bw_exponent)); + SET_CHECKED(rf69_set_bandwidth_during_afc(dev->spi, rx_cfg->bw_mantisse, rx_cfg->bw_exponent)); + SET_CHECKED(rf69_set_dagc (dev->spi, rx_cfg->dagc)); + + dev->rx_bytes_to_drop = rx_cfg->bytes_to_drop; + + /* packet config */ + /* enable */ + SET_CHECKED(rf69_set_sync_enable(dev->spi, rx_cfg->enable_sync)); + if (rx_cfg->enable_sync == optionOn) + { + SET_CHECKED(rf69_set_fifo_fill_condition(dev->spi, afterSyncInterrupt)); + } + else + { + SET_CHECKED(rf69_set_fifo_fill_condition(dev->spi, always)); + } + if (rx_cfg->enable_length_byte == optionOn) { + ret = rf69_set_packet_format(dev->spi, packetLengthVar); + if (ret < 0) + return ret; + } else { + ret = rf69_set_packet_format(dev->spi, packetLengthFix); + if (ret < 0) + return ret; + } + SET_CHECKED(rf69_set_adressFiltering(dev->spi, rx_cfg->enable_address_filtering)); + SET_CHECKED(rf69_set_crc_enable (dev->spi, rx_cfg->enable_crc)); + + /* lengths */ + SET_CHECKED(rf69_set_sync_size(dev->spi, rx_cfg->sync_length)); + if (rx_cfg->enable_length_byte == optionOn) + { + SET_CHECKED(rf69_set_payload_length(dev->spi, 0xff)); + } + else if (rx_cfg->fixed_message_length != 0) + { + payload_length = rx_cfg->fixed_message_length; + if (rx_cfg->enable_length_byte == optionOn) payload_length++; + if (rx_cfg->enable_address_filtering != filteringOff) payload_length++; + SET_CHECKED(rf69_set_payload_length(dev->spi, payload_length)); + } + else + { + SET_CHECKED(rf69_set_payload_length(dev->spi, 0)); + } + + /* values */ + if (rx_cfg->enable_sync == optionOn) + { + SET_CHECKED(rf69_set_sync_values(dev->spi, rx_cfg->sync_pattern)); + } + if (rx_cfg->enable_address_filtering != filteringOff) + { + SET_CHECKED(rf69_set_node_address (dev->spi, rx_cfg->node_address)); + SET_CHECKED(rf69_set_broadcast_address(dev->spi, rx_cfg->broadcast_address)); + } + + return 0; +} + +static int +rf69_set_tx_cfg(struct pi433_device *dev, struct pi433_tx_cfg *tx_cfg) +{ + int ret; + + SET_CHECKED(rf69_set_frequency (dev->spi, tx_cfg->frequency)); + SET_CHECKED(rf69_set_bit_rate (dev->spi, tx_cfg->bit_rate)); + SET_CHECKED(rf69_set_modulation (dev->spi, tx_cfg->modulation)); + SET_CHECKED(rf69_set_deviation (dev->spi, tx_cfg->dev_frequency)); + SET_CHECKED(rf69_set_pa_ramp (dev->spi, tx_cfg->pa_ramp)); + SET_CHECKED(rf69_set_modulation_shaping(dev->spi, tx_cfg->modShaping)); + SET_CHECKED(rf69_set_tx_start_condition(dev->spi, tx_cfg->tx_start_condition)); + + /* packet format enable */ + if (tx_cfg->enable_preamble == optionOn) + { + SET_CHECKED(rf69_set_preamble_length(dev->spi, tx_cfg->preamble_length)); + } + else + { + SET_CHECKED(rf69_set_preamble_length(dev->spi, 0)); + } + SET_CHECKED(rf69_set_sync_enable (dev->spi, tx_cfg->enable_sync)); + if (tx_cfg->enable_length_byte == optionOn) { + ret = rf69_set_packet_format(dev->spi, packetLengthVar); + if (ret < 0) + return ret; + } else { + ret = rf69_set_packet_format(dev->spi, packetLengthFix); + if (ret < 0) + return ret; + } + SET_CHECKED(rf69_set_crc_enable (dev->spi, tx_cfg->enable_crc)); + + /* configure sync, if enabled */ + if (tx_cfg->enable_sync == optionOn) + { + SET_CHECKED(rf69_set_sync_size(dev->spi, tx_cfg->sync_length)); + SET_CHECKED(rf69_set_sync_values(dev->spi, tx_cfg->sync_pattern)); + } + + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static int +pi433_start_rx(struct pi433_device *dev) +{ + int retval; + + /* return without action, if no pending read request */ + if (!dev->rx_active) + return 0; + + /* setup for receiving */ + retval = rf69_set_rx_cfg(dev, &dev->rx_cfg); + if (retval) return retval; + + /* setup rssi irq */ + SET_CHECKED(rf69_set_dio_mapping(dev->spi, DIO0, DIO_Rssi_DIO0)); + dev->irq_state[DIO0] = DIO_Rssi_DIO0; + irq_set_irq_type(dev->irq_num[DIO0], IRQ_TYPE_EDGE_RISING); + + /* setup fifo level interrupt */ + SET_CHECKED(rf69_set_fifo_threshold(dev->spi, FIFO_SIZE - FIFO_THRESHOLD)); + SET_CHECKED(rf69_set_dio_mapping(dev->spi, DIO1, DIO_FifoLevel)); + dev->irq_state[DIO1] = DIO_FifoLevel; + irq_set_irq_type(dev->irq_num[DIO1], IRQ_TYPE_EDGE_RISING); + + /* set module to receiving mode */ + SET_CHECKED(rf69_set_mode(dev->spi, receive)); + + return 0; +} + + +/*-------------------------------------------------------------------------*/ + +static int +pi433_receive(void *data) +{ + struct pi433_device *dev = data; + struct spi_device *spi = dev->spi; /* needed for SET_CHECKED */ + int bytes_to_read, bytes_total; + int retval; + + dev->interrupt_rx_allowed = false; + + /* wait for any tx to finish */ + dev_dbg(dev->dev,"rx: going to wait for any tx to finish"); + retval = wait_event_interruptible(dev->rx_wait_queue, !dev->tx_active); + if(retval) /* wait was interrupted */ + { + dev->interrupt_rx_allowed = true; + wake_up_interruptible(&dev->tx_wait_queue); + return retval; + } + + /* prepare status vars */ + dev->free_in_fifo = FIFO_SIZE; + dev->rx_position = 0; + dev->rx_bytes_dropped = 0; + + /* setup radio module to listen for something "in the air" */ + retval = pi433_start_rx(dev); + if (retval) + return retval; + + /* now check RSSI, if low wait for getting high (RSSI interrupt) */ + while ( !rf69_get_flag(dev->spi, rssiExceededThreshold) ) + { + /* allow tx to interrupt us while waiting for high RSSI */ + dev->interrupt_rx_allowed = true; + wake_up_interruptible(&dev->tx_wait_queue); + + /* wait for RSSI level to become high */ + dev_dbg(dev->dev, "rx: going to wait for high RSSI level"); + retval = wait_event_interruptible(dev->rx_wait_queue, + rf69_get_flag(dev->spi, + rssiExceededThreshold)); + if (retval) goto abort; /* wait was interrupted */ + dev->interrupt_rx_allowed = false; + + /* cross check for ongoing tx */ + if (!dev->tx_active) break; + } + + /* configure payload ready irq */ + SET_CHECKED(rf69_set_dio_mapping(spi, DIO0, DIO_PayloadReady)); + dev->irq_state[DIO0] = DIO_PayloadReady; + irq_set_irq_type(dev->irq_num[DIO0], IRQ_TYPE_EDGE_RISING); + + /* fixed or unlimited length? */ + if (dev->rx_cfg.fixed_message_length != 0) + { + if (dev->rx_cfg.fixed_message_length > dev->rx_buffer_size) + { + retval = -1; + goto abort; + } + bytes_total = dev->rx_cfg.fixed_message_length; + dev_dbg(dev->dev,"rx: msg len set to %d by fixed length", bytes_total); + } + else + { + bytes_total = dev->rx_buffer_size; + dev_dbg(dev->dev, "rx: msg len set to %d as requested by read", bytes_total); + } + + /* length byte enabled? */ + if (dev->rx_cfg.enable_length_byte == optionOn) + { + retval = wait_event_interruptible(dev->fifo_wait_queue, + dev->free_in_fifo < FIFO_SIZE); + if (retval) goto abort; /* wait was interrupted */ + + rf69_read_fifo(spi, (u8 *)&bytes_total, 1); + if (bytes_total > dev->rx_buffer_size) + { + retval = -1; + goto abort; + } + dev->free_in_fifo++; + dev_dbg(dev->dev, "rx: msg len reset to %d due to length byte", bytes_total); + } + + /* address byte enabled? */ + if (dev->rx_cfg.enable_address_filtering != filteringOff) + { + u8 dummy; + + bytes_total--; + + retval = wait_event_interruptible(dev->fifo_wait_queue, + dev->free_in_fifo < FIFO_SIZE); + if (retval) goto abort; /* wait was interrupted */ + + rf69_read_fifo(spi, &dummy, 1); + dev->free_in_fifo++; + dev_dbg(dev->dev, "rx: address byte stripped off"); + } + + /* get payload */ + while (dev->rx_position < bytes_total) + { + if ( !rf69_get_flag(dev->spi, payloadReady) ) + { + retval = wait_event_interruptible(dev->fifo_wait_queue, + dev->free_in_fifo < FIFO_SIZE); + if (retval) goto abort; /* wait was interrupted */ + } + + /* need to drop bytes or acquire? */ + if (dev->rx_bytes_to_drop > dev->rx_bytes_dropped) + bytes_to_read = dev->rx_bytes_to_drop - dev->rx_bytes_dropped; + else + bytes_to_read = bytes_total - dev->rx_position; + + + /* access the fifo */ + if (bytes_to_read > FIFO_SIZE - dev->free_in_fifo) + bytes_to_read = FIFO_SIZE - dev->free_in_fifo; + retval = rf69_read_fifo(spi, + &dev->rx_buffer[dev->rx_position], + bytes_to_read); + if (retval) goto abort; /* read failed */ + dev->free_in_fifo += bytes_to_read; + + /* adjust status vars */ + if (dev->rx_bytes_to_drop > dev->rx_bytes_dropped) + dev->rx_bytes_dropped += bytes_to_read; + else + dev->rx_position += bytes_to_read; + } + + + /* rx done, wait was interrupted or error occured */ +abort: + dev->interrupt_rx_allowed = true; + SET_CHECKED(rf69_set_mode(dev->spi, standby)); + wake_up_interruptible(&dev->tx_wait_queue); + + if (retval) + return retval; + else + return bytes_total; +} + +static int +pi433_tx_thread(void *data) +{ + struct pi433_device *device = data; + struct spi_device *spi = device->spi; /* needed for SET_CHECKED */ + struct pi433_tx_cfg tx_cfg; + u8 *buffer = device->buffer; + size_t size; + bool rx_interrupted = false; + int position, repetitions; + int retval; + + while (1) + { + /* wait for fifo to be populated or for request to terminate*/ + dev_dbg(device->dev, "thread: going to wait for new messages"); + wait_event_interruptible(device->tx_wait_queue, + ( !kfifo_is_empty(&device->tx_fifo) || + kthread_should_stop() )); + if ( kthread_should_stop() ) + return 0; + + /* get data from fifo in the following order: + * - tx_cfg + * - size of message + * - message + */ + mutex_lock(&device->tx_fifo_lock); + + retval = kfifo_out(&device->tx_fifo, &tx_cfg, sizeof(tx_cfg)); + if (retval != sizeof(tx_cfg)) + { + dev_dbg(device->dev, "reading tx_cfg from fifo failed: got %d byte(s), expected %d", retval, (unsigned int)sizeof(tx_cfg) ); + mutex_unlock(&device->tx_fifo_lock); + continue; + } + + retval = kfifo_out(&device->tx_fifo, &size, sizeof(size_t)); + if (retval != sizeof(size_t)) + { + dev_dbg(device->dev, "reading msg size from fifo failed: got %d, expected %d", retval, (unsigned int)sizeof(size_t) ); + mutex_unlock(&device->tx_fifo_lock); + continue; + } + + /* use fixed message length, if requested */ + if (tx_cfg.fixed_message_length != 0) + size = tx_cfg.fixed_message_length; + + /* increase size, if len byte is requested */ + if (tx_cfg.enable_length_byte == optionOn) + size++; + + /* increase size, if adr byte is requested */ + if (tx_cfg.enable_address_byte == optionOn) + size++; + + /* prime buffer */ + memset(buffer, 0, size); + position = 0; + + /* add length byte, if requested */ + if (tx_cfg.enable_length_byte == optionOn) + buffer[position++] = size-1; /* according to spec length byte itself must be excluded from the length calculation */ + + /* add adr byte, if requested */ + if (tx_cfg.enable_address_byte == optionOn) + buffer[position++] = tx_cfg.address_byte; + + /* finally get message data from fifo */ + retval = kfifo_out(&device->tx_fifo, &buffer[position], sizeof(buffer)-position ); + dev_dbg(device->dev, "read %d message byte(s) from fifo queue.", retval); + mutex_unlock(&device->tx_fifo_lock); + + /* if rx is active, we need to interrupt the waiting for + * incoming telegrams, to be able to send something. + * We are only allowed, if currently no reception takes + * place otherwise we need to wait for the incoming telegram + * to finish + */ + wait_event_interruptible(device->tx_wait_queue, + !device->rx_active || + device->interrupt_rx_allowed == true); + + /* prevent race conditions + * irq will be reenabled after tx config is set + */ + disable_irq(device->irq_num[DIO0]); + device->tx_active = true; + + if (device->rx_active && rx_interrupted == false) + { + /* rx is currently waiting for a telegram; + * we need to set the radio module to standby + */ + SET_CHECKED(rf69_set_mode(device->spi, standby)); + rx_interrupted = true; + } + + /* clear fifo, set fifo threshold, set payload length */ + SET_CHECKED(rf69_set_mode(spi, standby)); /* this clears the fifo */ + SET_CHECKED(rf69_set_fifo_threshold(spi, FIFO_THRESHOLD)); + if (tx_cfg.enable_length_byte == optionOn) + { + SET_CHECKED(rf69_set_payload_length(spi, size * tx_cfg.repetitions)); + } + else + { + SET_CHECKED(rf69_set_payload_length(spi, 0)); + } + + /* configure the rf chip */ + rf69_set_tx_cfg(device, &tx_cfg); + + /* enable fifo level interrupt */ + SET_CHECKED(rf69_set_dio_mapping(spi, DIO1, DIO_FifoLevel)); + device->irq_state[DIO1] = DIO_FifoLevel; + irq_set_irq_type(device->irq_num[DIO1], IRQ_TYPE_EDGE_FALLING); + + /* enable packet sent interrupt */ + SET_CHECKED(rf69_set_dio_mapping(spi, DIO0, DIO_PacketSent)); + device->irq_state[DIO0] = DIO_PacketSent; + irq_set_irq_type(device->irq_num[DIO0], IRQ_TYPE_EDGE_RISING); + enable_irq(device->irq_num[DIO0]); /* was disabled by rx active check */ + + /* enable transmission */ + SET_CHECKED(rf69_set_mode(spi, transmit)); + + /* transfer this msg (and repetitions) to chip fifo */ + device->free_in_fifo = FIFO_SIZE; + position = 0; + repetitions = tx_cfg.repetitions; + while( (repetitions > 0) && (size > position) ) + { + if ( (size - position) > device->free_in_fifo) + { /* msg to big for fifo - take a part */ + int temp = device->free_in_fifo; + device->free_in_fifo = 0; + rf69_write_fifo(spi, + &buffer[position], + temp); + position +=temp; + } + else + { /* msg fits into fifo - take all */ + device->free_in_fifo -= size; + repetitions--; + rf69_write_fifo(spi, + &buffer[position], + (size - position) ); + position = 0; /* reset for next repetition */ + } + + retval = wait_event_interruptible(device->fifo_wait_queue, + device->free_in_fifo > 0); + if (retval) { printk("ABORT\n"); goto abort; } + } + + /* we are done. Wait for packet to get sent */ + dev_dbg(device->dev, "thread: wait for packet to get sent/fifo to be empty"); + wait_event_interruptible(device->fifo_wait_queue, + device->free_in_fifo == FIFO_SIZE || + kthread_should_stop() ); + if ( kthread_should_stop() ) printk("ABORT\n"); + + + /* STOP_TRANSMISSION */ + dev_dbg(device->dev, "thread: Packet sent. Set mode to stby."); + SET_CHECKED(rf69_set_mode(spi, standby)); + + /* everything sent? */ + if ( kfifo_is_empty(&device->tx_fifo) ) + { +abort: + if (rx_interrupted) + { + rx_interrupted = false; + pi433_start_rx(device); + } + device->tx_active = false; + wake_up_interruptible(&device->rx_wait_queue); + } + } +} + +/*-------------------------------------------------------------------------*/ + +static ssize_t +pi433_read(struct file *filp, char __user *buf, size_t size, loff_t *f_pos) +{ + struct pi433_instance *instance; + struct pi433_device *device; + int bytes_received; + ssize_t retval; + + /* check, whether internal buffer is big enough for requested size */ + if (size > MAX_MSG_SIZE) + return -EMSGSIZE; + + instance = filp->private_data; + device = instance->device; + + /* just one read request at a time */ + mutex_lock(&device->rx_lock); + if (device->rx_active) + { + mutex_unlock(&device->rx_lock); + return -EAGAIN; + } + else + { + device->rx_active = true; + mutex_unlock(&device->rx_lock); + } + + /* start receiving */ + /* will block until something was received*/ + device->rx_buffer_size = size; + bytes_received = pi433_receive(device); + + /* release rx */ + mutex_lock(&device->rx_lock); + device->rx_active = false; + mutex_unlock(&device->rx_lock); + + /* if read was successful copy to user space*/ + if (bytes_received > 0) + { + retval = copy_to_user(buf, device->rx_buffer, bytes_received); + if (retval) + return -EFAULT; + } + + return bytes_received; +} + + +static ssize_t +pi433_write(struct file *filp, const char __user *buf, + size_t count, loff_t *f_pos) +{ + struct pi433_instance *instance; + struct pi433_device *device; + int copied, retval; + + instance = filp->private_data; + device = instance->device; + + /* check, whether internal buffer (tx thread) is big enough for requested size */ + if (count > MAX_MSG_SIZE) + return -EMSGSIZE; + + /* write the following sequence into fifo: + * - tx_cfg + * - size of message + * - message + */ + mutex_lock(&device->tx_fifo_lock); + retval = kfifo_in(&device->tx_fifo, &instance->tx_cfg, sizeof(instance->tx_cfg)); + if ( retval != sizeof(instance->tx_cfg) ) + goto abort; + + retval = kfifo_in (&device->tx_fifo, &count, sizeof(size_t)); + if ( retval != sizeof(size_t) ) + goto abort; + + retval = kfifo_from_user(&device->tx_fifo, buf, count, &copied); + if (retval || copied != count) + goto abort; + + mutex_unlock(&device->tx_fifo_lock); + + /* start transfer */ + wake_up_interruptible(&device->tx_wait_queue); + dev_dbg(device->dev, "write: generated new msg with %d bytes.", copied); + + return 0; + +abort: + dev_dbg(device->dev, "write to fifo failed: 0x%x", retval); + kfifo_reset(&device->tx_fifo); // TODO: maybe find a solution, not to discard already stored, valid entries + mutex_unlock(&device->tx_fifo_lock); + return -EAGAIN; +} + + +static long +pi433_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + int err = 0; + int retval = 0; + struct pi433_instance *instance; + struct pi433_device *device; + u32 tmp; + + /* Check type and command number */ + if (_IOC_TYPE(cmd) != PI433_IOC_MAGIC) + return -ENOTTY; + + /* Check access direction once here; don't repeat below. + * IOC_DIR is from the user perspective, while access_ok is + * from the kernel perspective; so they look reversed. + */ + if (_IOC_DIR(cmd) & _IOC_READ) + err = !access_ok(VERIFY_WRITE, + (void __user *)arg, + _IOC_SIZE(cmd)); + + if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE) + err = !access_ok(VERIFY_READ, + (void __user *)arg, + _IOC_SIZE(cmd)); + if (err) + return -EFAULT; + + /* TODO? guard against device removal before, or while, + * we issue this ioctl. --> device_get() + */ + instance = filp->private_data; + device = instance->device; + + if (device == NULL) + return -ESHUTDOWN; + + switch (cmd) { + case PI433_IOC_RD_TX_CFG: + tmp = _IOC_SIZE(cmd); + if ( (tmp == 0) || ((tmp % sizeof(struct pi433_tx_cfg)) != 0) ) + { + retval = -EINVAL; + break; + } + + if (__copy_to_user((void __user *)arg, + &instance->tx_cfg, + tmp)) + { + retval = -EFAULT; + break; + } + + break; + case PI433_IOC_WR_TX_CFG: + tmp = _IOC_SIZE(cmd); + if ( (tmp == 0) || ((tmp % sizeof(struct pi433_tx_cfg)) != 0) ) + { + retval = -EINVAL; + break; + } + + if (__copy_from_user(&instance->tx_cfg, + (void __user *)arg, + tmp)) + { + retval = -EFAULT; + break; + } + + break; + + case PI433_IOC_RD_RX_CFG: + tmp = _IOC_SIZE(cmd); + if ( (tmp == 0) || ((tmp % sizeof(struct pi433_rx_cfg)) != 0) ) { + retval = -EINVAL; + break; + } + + if (__copy_to_user((void __user *)arg, + &device->rx_cfg, + tmp)) + { + retval = -EFAULT; + break; + } + + break; + case PI433_IOC_WR_RX_CFG: + tmp = _IOC_SIZE(cmd); + mutex_lock(&device->rx_lock); + + /* during pendig read request, change of config not allowed */ + if (device->rx_active) { + retval = -EAGAIN; + mutex_unlock(&device->rx_lock); + break; + } + + if ( (tmp == 0) || ((tmp % sizeof(struct pi433_rx_cfg)) != 0) ) { + retval = -EINVAL; + mutex_unlock(&device->rx_lock); + break; + } + + if (__copy_from_user(&device->rx_cfg, + (void __user *)arg, + tmp)) + { + retval = -EFAULT; + mutex_unlock(&device->rx_lock); + break; + } + + mutex_unlock(&device->rx_lock); + break; + default: + retval = -EINVAL; + } + + return retval; +} + +#ifdef CONFIG_COMPAT +static long +pi433_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + return pi433_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); +} +#else +#define pi433_compat_ioctl NULL +#endif /* CONFIG_COMPAT */ + +/*-------------------------------------------------------------------------*/ + +static int pi433_open(struct inode *inode, struct file *filp) +{ + struct pi433_device *device; + struct pi433_instance *instance; + + mutex_lock(&minor_lock); + device = idr_find(&pi433_idr, iminor(inode)); + mutex_unlock(&minor_lock); + if (!device) { + pr_debug("device: minor %d unknown.\n", iminor(inode)); + return -ENODEV; + } + + if (!device->rx_buffer) { + device->rx_buffer = kmalloc(MAX_MSG_SIZE, GFP_KERNEL); + if (!device->rx_buffer) + { + dev_dbg(device->dev, "open/ENOMEM\n"); + return -ENOMEM; + } + } + + device->users++; + instance = kzalloc(sizeof(*instance), GFP_KERNEL); + if (!instance) + { + kfree(device->rx_buffer); + device->rx_buffer = NULL; + return -ENOMEM; + } + + /* setup instance data*/ + instance->device = device; + instance->tx_cfg.bit_rate = 4711; + // TODO: fill instance->tx_cfg; + + /* instance data as context */ + filp->private_data = instance; + nonseekable_open(inode, filp); + + return 0; +} + +static int pi433_release(struct inode *inode, struct file *filp) +{ + struct pi433_instance *instance; + struct pi433_device *device; + + instance = filp->private_data; + device = instance->device; + kfree(instance); + filp->private_data = NULL; + + /* last close? */ + device->users--; + + if (!device->users) { + kfree(device->rx_buffer); + device->rx_buffer = NULL; + if (device->spi == NULL) + kfree(device); + } + + return 0; +} + + +/*-------------------------------------------------------------------------*/ + +static int setup_GPIOs(struct pi433_device *device) +{ + char name[5]; + int retval; + int i; + const irq_handler_t DIO_irq_handler[NUM_DIO] = { + DIO0_irq_handler, + DIO1_irq_handler + }; + + for (i=0; i<NUM_DIO; i++) + { + /* "construct" name and get the gpio descriptor */ + snprintf(name, sizeof(name), "DIO%d", i); + device->gpiod[i] = gpiod_get(&device->spi->dev, name, 0 /*GPIOD_IN*/); + + if (device->gpiod[i] == ERR_PTR(-ENOENT)) + { + dev_dbg(&device->spi->dev, "Could not find entry for %s. Ignoring.", name); + continue; + } + + if (device->gpiod[i] == ERR_PTR(-EBUSY)) + dev_dbg(&device->spi->dev, "%s is busy.", name); + + if ( IS_ERR(device->gpiod[i]) ) + { + retval = PTR_ERR(device->gpiod[i]); + /* release already allocated gpios */ + for (i--; i>=0; i--) + { + free_irq(device->irq_num[i], device); + gpiod_put(device->gpiod[i]); + } + return retval; + } + + + /* configure the pin */ + gpiod_unexport(device->gpiod[i]); + retval = gpiod_direction_input(device->gpiod[i]); + if (retval) return retval; + + + /* configure irq */ + device->irq_num[i] = gpiod_to_irq(device->gpiod[i]); + if (device->irq_num[i] < 0) + { + device->gpiod[i] = ERR_PTR(-EINVAL);//(struct gpio_desc *)device->irq_num[i]; + return device->irq_num[i]; + } + retval = request_irq(device->irq_num[i], + DIO_irq_handler[i], + 0, /* flags */ + name, + device); + + if (retval) + return retval; + + dev_dbg(&device->spi->dev, "%s succesfully configured", name); + } + + return 0; +} + +static void free_GPIOs(struct pi433_device *device) +{ + int i; + + for (i=0; i<NUM_DIO; i++) + { + /* check if gpiod is valid */ + if ( IS_ERR(device->gpiod[i]) ) + continue; + + free_irq(device->irq_num[i], device); + gpiod_put(device->gpiod[i]); + } + return; +} + +static int pi433_get_minor(struct pi433_device *device) +{ + int retval = -ENOMEM; + + mutex_lock(&minor_lock); + retval = idr_alloc(&pi433_idr, device, 0, N_PI433_MINORS, GFP_KERNEL); + if (retval >= 0) { + device->minor = retval; + retval = 0; + } else if (retval == -ENOSPC) { + dev_err(device->dev, "too many pi433 devices\n"); + retval = -EINVAL; + } + mutex_unlock(&minor_lock); + return retval; +} + +static void pi433_free_minor(struct pi433_device *dev) +{ + mutex_lock(&minor_lock); + idr_remove(&pi433_idr, dev->minor); + mutex_unlock(&minor_lock); +} +/*-------------------------------------------------------------------------*/ + +static const struct file_operations pi433_fops = { + .owner = THIS_MODULE, + /* REVISIT switch to aio primitives, so that userspace + * gets more complete API coverage. It'll simplify things + * too, except for the locking. + */ + .write = pi433_write, + .read = pi433_read, + .unlocked_ioctl = pi433_ioctl, + .compat_ioctl = pi433_compat_ioctl, + .open = pi433_open, + .release = pi433_release, + .llseek = no_llseek, +}; + +/*-------------------------------------------------------------------------*/ + +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; + } + else + { + 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 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_GPIOs(device); + if (retval) + { + dev_dbg(&spi->dev, "setup of GPIOs failed"); + goto GPIO_failed; + } + + /* setup the radio module */ + SET_CHECKED(rf69_set_mode (spi, standby)); + SET_CHECKED(rf69_set_data_mode (spi, packet)); + SET_CHECKED(rf69_set_amplifier_0 (spi, optionOn)); + SET_CHECKED(rf69_set_amplifier_1 (spi, optionOff)); + SET_CHECKED(rf69_set_amplifier_2 (spi, optionOff)); + SET_CHECKED(rf69_set_output_power_level (spi, 13)); + SET_CHECKED(rf69_set_antenna_impedance (spi, fiftyOhm)); + + /* start tx thread */ + device->tx_task_struct = kthread_run(pi433_tx_thread, + device, + "pi433_tx_task"); + if (IS_ERR(device->tx_task_struct)) + { + dev_dbg(device->dev, "start of send thread failed"); + goto send_thread_failed; + } + + /* determ minor number */ + retval = pi433_get_minor(device); + if (retval) + { + dev_dbg(device->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"); + 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); + } + + /* create cdev */ + device->cdev = cdev_alloc(); + 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 cdev_failed; + } + + /* spi setup */ + spi_set_drvdata(spi, device); + + return 0; + +cdev_failed: + device_destroy(pi433_class, device->devt); +device_create_failed: + pi433_free_minor(device); +minor_failed: + kthread_stop(device->tx_task_struct); +send_thread_failed: + free_GPIOs(device); +GPIO_failed: + kfree(device); + + return retval; +} + +static int pi433_remove(struct spi_device *spi) +{ + struct pi433_device *device = spi_get_drvdata(spi); + + /* free GPIOs */ + free_GPIOs(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); + + if (device->users == 0) + kfree(device); + + return 0; +} + +static const struct of_device_id pi433_dt_ids[] = { + { .compatible = "Smarthome-Wolf,pi433" }, + {}, +}; + +MODULE_DEVICE_TABLE(of, pi433_dt_ids); + +static struct spi_driver pi433_spi_driver = { + .driver = { + .name = "pi433", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(pi433_dt_ids), + }, + .probe = pi433_probe, + .remove = pi433_remove, + + /* NOTE: suspend/resume methods are not necessary here. + * We don't do anything except pass the requests to/from + * the underlying controller. The refrigerator handles + * most issues; the controller driver handles the rest. + */ +}; + +/*-------------------------------------------------------------------------*/ + +static int __init pi433_init(void) +{ + int status; + + /* If MAX_MSG_SIZE is smaller then FIFO_SIZE, the driver won't + * work stable - risk of buffer overflow + */ + if (MAX_MSG_SIZE < FIFO_SIZE) + return -EINVAL; + + /* Claim device numbers. Then register a class + * that will key udev/mdev to add/remove /dev nodes. Last, register + * Last, register the driver which manages those device numbers. + */ + status = alloc_chrdev_region(&pi433_dev, 0 /*firstminor*/, N_PI433_MINORS /*count*/, "pi433" /*name*/); + if (status < 0) + return status; + + pi433_class = class_create(THIS_MODULE, "pi433"); + if (IS_ERR(pi433_class)) + { + unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name); + return PTR_ERR(pi433_class); + } + + status = spi_register_driver(&pi433_spi_driver); + if (status < 0) + { + class_destroy(pi433_class); + unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name); + } + + return status; +} + +module_init(pi433_init); + +static void __exit pi433_exit(void) +{ + spi_unregister_driver(&pi433_spi_driver); + class_destroy(pi433_class); + unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name); +} +module_exit(pi433_exit); + +MODULE_AUTHOR("Marcus Wolf, <linux@wolf-entwicklungen.de>"); +MODULE_DESCRIPTION("Driver for Pi433"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("spi:pi433"); |