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1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 | // SPDX-License-Identifier: GPL-2.0+ /* * 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> */ #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/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 <linux/compat.h> #endif #include <linux/debugfs.h> #include <linux/seq_file.h> #include "pi433_if.h" #include "rf69.h" #define N_PI433_MINORS BIT(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 dentry *root_dir; /* debugfs root directory for the driver */ 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; /* 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; /* serialize userspace writers */ 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; /* protects rx_* variable accesses */ 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; /* control flags */ bool tx_cfg_initialized; }; /*-------------------------------------------------------------------------*/ /* 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_PACKET_SENT) { device->free_in_fifo = FIFO_SIZE; dev_dbg(device->dev, "DIO0 irq: Packet sent\n"); wake_up_interruptible(&device->fifo_wait_queue); } else if (device->irq_state[DIO0] == DIO_RSSI_DIO0) { dev_dbg(device->dev, "DIO0 irq: RSSI level over threshold\n"); wake_up_interruptible(&device->rx_wait_queue); } else if (device->irq_state[DIO0] == DIO_PAYLOAD_READY) { dev_dbg(device->dev, "DIO0 irq: Payload ready\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_FIFO_NOT_EMPTY_DIO1) { device->free_in_fifo = FIFO_SIZE; } else if (device->irq_state[DIO1] == DIO_FIFO_LEVEL) { if (device->rx_active) device->free_in_fifo = FIFO_THRESHOLD - 1; else device->free_in_fifo = FIFO_SIZE - FIFO_THRESHOLD - 1; } dev_dbg(device->dev, "DIO1 irq: %d bytes free in fifo\n", device->free_in_fifo); 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 */ ret = rf69_set_frequency(dev->spi, rx_cfg->frequency); if (ret < 0) return ret; ret = rf69_set_modulation(dev->spi, rx_cfg->modulation); if (ret < 0) return ret; ret = rf69_set_bit_rate(dev->spi, rx_cfg->bit_rate); if (ret < 0) return ret; ret = rf69_set_antenna_impedance(dev->spi, rx_cfg->antenna_impedance); if (ret < 0) return ret; ret = rf69_set_rssi_threshold(dev->spi, rx_cfg->rssi_threshold); if (ret < 0) return ret; ret = rf69_set_ook_threshold_dec(dev->spi, rx_cfg->threshold_decrement); if (ret < 0) return ret; ret = rf69_set_bandwidth(dev->spi, rx_cfg->bw_mantisse, rx_cfg->bw_exponent); if (ret < 0) return ret; ret = rf69_set_bandwidth_during_afc(dev->spi, rx_cfg->bw_mantisse, rx_cfg->bw_exponent); if (ret < 0) return ret; ret = rf69_set_dagc(dev->spi, rx_cfg->dagc); if (ret < 0) return ret; dev->rx_bytes_to_drop = rx_cfg->bytes_to_drop; /* packet config */ /* enable */ if (rx_cfg->enable_sync == OPTION_ON) { ret = rf69_enable_sync(dev->spi); if (ret < 0) return ret; ret = rf69_set_fifo_fill_condition(dev->spi, after_sync_interrupt); if (ret < 0) return ret; } else { ret = rf69_disable_sync(dev->spi); if (ret < 0) return ret; ret = rf69_set_fifo_fill_condition(dev->spi, always); if (ret < 0) return ret; } if (rx_cfg->enable_length_byte == OPTION_ON) { ret = rf69_set_packet_format(dev->spi, packet_length_var); if (ret < 0) return ret; } else { ret = rf69_set_packet_format(dev->spi, packet_length_fix); if (ret < 0) return ret; } ret = rf69_set_address_filtering(dev->spi, rx_cfg->enable_address_filtering); if (ret < 0) return ret; if (rx_cfg->enable_crc == OPTION_ON) { ret = rf69_enable_crc(dev->spi); if (ret < 0) return ret; } else { ret = rf69_disable_crc(dev->spi); if (ret < 0) return ret; } /* lengths */ ret = rf69_set_sync_size(dev->spi, rx_cfg->sync_length); if (ret < 0) return ret; if (rx_cfg->enable_length_byte == OPTION_ON) { ret = rf69_set_payload_length(dev->spi, 0xff); if (ret < 0) return ret; } else if (rx_cfg->fixed_message_length != 0) { payload_length = rx_cfg->fixed_message_length; if (rx_cfg->enable_length_byte == OPTION_ON) payload_length++; if (rx_cfg->enable_address_filtering != filtering_off) payload_length++; ret = rf69_set_payload_length(dev->spi, payload_length); if (ret < 0) return ret; } else { ret = rf69_set_payload_length(dev->spi, 0); if (ret < 0) return ret; } /* values */ if (rx_cfg->enable_sync == OPTION_ON) { ret = rf69_set_sync_values(dev->spi, rx_cfg->sync_pattern); if (ret < 0) return ret; } if (rx_cfg->enable_address_filtering != filtering_off) { ret = rf69_set_node_address(dev->spi, rx_cfg->node_address); if (ret < 0) return ret; ret = rf69_set_broadcast_address(dev->spi, rx_cfg->broadcast_address); if (ret < 0) return ret; } return 0; } static int rf69_set_tx_cfg(struct pi433_device *dev, struct pi433_tx_cfg *tx_cfg) { int ret; ret = rf69_set_frequency(dev->spi, tx_cfg->frequency); if (ret < 0) return ret; ret = rf69_set_modulation(dev->spi, tx_cfg->modulation); if (ret < 0) return ret; ret = rf69_set_bit_rate(dev->spi, tx_cfg->bit_rate); if (ret < 0) return ret; ret = rf69_set_deviation(dev->spi, tx_cfg->dev_frequency); if (ret < 0) return ret; ret = rf69_set_pa_ramp(dev->spi, tx_cfg->pa_ramp); if (ret < 0) return ret; ret = rf69_set_modulation_shaping(dev->spi, tx_cfg->mod_shaping); if (ret < 0) return ret; ret = rf69_set_tx_start_condition(dev->spi, tx_cfg->tx_start_condition); if (ret < 0) return ret; /* packet format enable */ if (tx_cfg->enable_preamble == OPTION_ON) { ret = rf69_set_preamble_length(dev->spi, tx_cfg->preamble_length); if (ret < 0) return ret; } else { ret = rf69_set_preamble_length(dev->spi, 0); if (ret < 0) return ret; } if (tx_cfg->enable_sync == OPTION_ON) { ret = rf69_set_sync_size(dev->spi, tx_cfg->sync_length); if (ret < 0) return ret; ret = rf69_set_sync_values(dev->spi, tx_cfg->sync_pattern); if (ret < 0) return ret; ret = rf69_enable_sync(dev->spi); if (ret < 0) return ret; } else { ret = rf69_disable_sync(dev->spi); if (ret < 0) return ret; } if (tx_cfg->enable_length_byte == OPTION_ON) { ret = rf69_set_packet_format(dev->spi, packet_length_var); if (ret < 0) return ret; } else { ret = rf69_set_packet_format(dev->spi, packet_length_fix); if (ret < 0) return ret; } if (tx_cfg->enable_crc == OPTION_ON) { ret = rf69_enable_crc(dev->spi); if (ret < 0) return ret; } else { ret = rf69_disable_crc(dev->spi); if (ret < 0) return ret; } 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 */ retval = rf69_set_dio_mapping(dev->spi, DIO0, DIO_RSSI_DIO0); if (retval < 0) return retval; dev->irq_state[DIO0] = DIO_RSSI_DIO0; irq_set_irq_type(dev->irq_num[DIO0], IRQ_TYPE_EDGE_RISING); /* setup fifo level interrupt */ retval = rf69_set_fifo_threshold(dev->spi, FIFO_SIZE - FIFO_THRESHOLD); if (retval < 0) return retval; retval = rf69_set_dio_mapping(dev->spi, DIO1, DIO_FIFO_LEVEL); if (retval < 0) return retval; dev->irq_state[DIO1] = DIO_FIFO_LEVEL; irq_set_irq_type(dev->irq_num[DIO1], IRQ_TYPE_EDGE_RISING); /* set module to receiving mode */ retval = rf69_set_mode(dev->spi, receive); if (retval < 0) return retval; return 0; } /*-------------------------------------------------------------------------*/ static int pi433_receive(void *data) { struct pi433_device *dev = data; struct spi_device *spi = dev->spi; 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\n"); 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_read_reg(spi, REG_IRQFLAGS1) & MASK_IRQFLAGS1_RSSI)) { /* 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\n"); retval = wait_event_interruptible(dev->rx_wait_queue, rf69_read_reg(spi, REG_IRQFLAGS1) & MASK_IRQFLAGS1_RSSI); if (retval) /* wait was interrupted */ goto abort; dev->interrupt_rx_allowed = false; /* cross check for ongoing tx */ if (!dev->tx_active) break; } /* configure payload ready irq */ retval = rf69_set_dio_mapping(spi, DIO0, DIO_PAYLOAD_READY); if (retval < 0) goto abort; dev->irq_state[DIO0] = DIO_PAYLOAD_READY; 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\n", bytes_total); } else { bytes_total = dev->rx_buffer_size; dev_dbg(dev->dev, "rx: msg len set to %d as requested by read\n", bytes_total); } /* length byte enabled? */ if (dev->rx_cfg.enable_length_byte == OPTION_ON) { retval = wait_event_interruptible(dev->fifo_wait_queue, dev->free_in_fifo < FIFO_SIZE); if (retval) /* wait was interrupted */ goto abort; 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\n", bytes_total); } /* address byte enabled? */ if (dev->rx_cfg.enable_address_filtering != filtering_off) { u8 dummy; bytes_total--; retval = wait_event_interruptible(dev->fifo_wait_queue, dev->free_in_fifo < FIFO_SIZE); if (retval) /* wait was interrupted */ goto abort; rf69_read_fifo(spi, &dummy, 1); dev->free_in_fifo++; dev_dbg(dev->dev, "rx: address byte stripped off\n"); } /* get payload */ while (dev->rx_position < bytes_total) { if (!(rf69_read_reg(spi, REG_IRQFLAGS2) & MASK_IRQFLAGS2_PAYLOAD_READY)) { retval = wait_event_interruptible(dev->fifo_wait_queue, dev->free_in_fifo < FIFO_SIZE); if (retval) /* wait was interrupted */ goto abort; } /* 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) /* read failed */ goto abort; 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 occurred */ abort: dev->interrupt_rx_allowed = true; if (rf69_set_mode(dev->spi, standby)) pr_err("rf69_set_mode(): radio module failed to go standby\n"); 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; struct pi433_tx_cfg tx_cfg; 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\n"); 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 */ 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\n", retval, (unsigned int)sizeof(tx_cfg)); 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\n", retval, (unsigned int)sizeof(size_t)); 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 == OPTION_ON) size++; /* increase size, if adr byte is requested */ if (tx_cfg.enable_address_byte == OPTION_ON) size++; /* prime buffer */ memset(device->buffer, 0, size); position = 0; /* add length byte, if requested */ if (tx_cfg.enable_length_byte == OPTION_ON) /* * according to spec, length byte itself must be * excluded from the length calculation */ device->buffer[position++] = size - 1; /* add adr byte, if requested */ if (tx_cfg.enable_address_byte == OPTION_ON) device->buffer[position++] = tx_cfg.address_byte; /* finally get message data from fifo */ retval = kfifo_out(&device->tx_fifo, &device->buffer[position], sizeof(device->buffer) - position); dev_dbg(device->dev, "read %d message byte(s) from fifo queue.\n", retval); /* * 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); /* * prevent race conditions * irq will be reenabled after tx config is set */ disable_irq(device->irq_num[DIO0]); device->tx_active = true; /* clear fifo, set fifo threshold, set payload length */ retval = rf69_set_mode(spi, standby); /* this clears the fifo */ if (retval < 0) goto abort; if (device->rx_active && !rx_interrupted) { /* * rx is currently waiting for a telegram; * we need to set the radio module to standby */ rx_interrupted = true; } retval = rf69_set_fifo_threshold(spi, FIFO_THRESHOLD); if (retval < 0) goto abort; if (tx_cfg.enable_length_byte == OPTION_ON) { retval = rf69_set_payload_length(spi, size * tx_cfg.repetitions); if (retval < 0) goto abort; } else { retval = rf69_set_payload_length(spi, 0); if (retval < 0) goto abort; } /* configure the rf chip */ retval = rf69_set_tx_cfg(device, &tx_cfg); if (retval < 0) goto abort; /* enable fifo level interrupt */ retval = rf69_set_dio_mapping(spi, DIO1, DIO_FIFO_LEVEL); if (retval < 0) goto abort; device->irq_state[DIO1] = DIO_FIFO_LEVEL; irq_set_irq_type(device->irq_num[DIO1], IRQ_TYPE_EDGE_FALLING); /* enable packet sent interrupt */ retval = rf69_set_dio_mapping(spi, DIO0, DIO_PACKET_SENT); if (retval < 0) goto abort; device->irq_state[DIO0] = DIO_PACKET_SENT; 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 */ retval = rf69_set_mode(spi, transmit); if (retval < 0) goto abort; /* 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 write_size = device->free_in_fifo; device->free_in_fifo = 0; rf69_write_fifo(spi, &device->buffer[position], write_size); position += write_size; } else { /* msg fits into fifo - take all */ device->free_in_fifo -= size; repetitions--; rf69_write_fifo(spi, &device->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) { dev_dbg(device->dev, "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\n"); wait_event_interruptible(device->fifo_wait_queue, device->free_in_fifo == FIFO_SIZE || kthread_should_stop()); if (kthread_should_stop()) return 0; /* STOP_TRANSMISSION */ dev_dbg(device->dev, "thread: Packet sent. Set mode to stby.\n"); retval = rf69_set_mode(spi, standby); if (retval < 0) goto abort; /* 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; } 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 retval; unsigned int required, available, copied; 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; /* * check if tx_cfg has been initialized otherwise we won't be able to * config the RF trasmitter correctly due to invalid settings */ if (!instance->tx_cfg_initialized) { dev_notice_once(device->dev, "write: failed due to unconfigured tx_cfg (see PI433_IOC_WR_TX_CFG)\n"); return -EINVAL; } /* * write the following sequence into fifo: * - tx_cfg * - size of message * - message */ mutex_lock(&device->tx_fifo_lock); required = sizeof(instance->tx_cfg) + sizeof(size_t) + count; available = kfifo_avail(&device->tx_fifo); if (required > available) { dev_dbg(device->dev, "write to fifo failed: %d bytes required but %d available\n", required, available); mutex_unlock(&device->tx_fifo_lock); return -EAGAIN; } 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.\n", copied); return copied; abort: dev_warn(device->dev, "write to fifo failed, non recoverable: 0x%x\n", retval); mutex_unlock(&device->tx_fifo_lock); return -EAGAIN; } static long pi433_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct pi433_instance *instance; struct pi433_device *device; struct pi433_tx_cfg tx_cfg; void __user *argp = (void __user *)arg; /* Check type and command number */ if (_IOC_TYPE(cmd) != PI433_IOC_MAGIC) return -ENOTTY; instance = filp->private_data; device = instance->device; if (!device) return -ESHUTDOWN; switch (cmd) { case PI433_IOC_RD_TX_CFG: if (copy_to_user(argp, &instance->tx_cfg, sizeof(struct pi433_tx_cfg))) return -EFAULT; break; case PI433_IOC_WR_TX_CFG: if (copy_from_user(&tx_cfg, argp, sizeof(struct pi433_tx_cfg))) return -EFAULT; mutex_lock(&device->tx_fifo_lock); memcpy(&instance->tx_cfg, &tx_cfg, sizeof(struct pi433_tx_cfg)); instance->tx_cfg_initialized = true; mutex_unlock(&device->tx_fifo_lock); break; case PI433_IOC_RD_RX_CFG: if (copy_to_user(argp, &device->rx_cfg, sizeof(struct pi433_rx_cfg))) return -EFAULT; break; case PI433_IOC_WR_RX_CFG: mutex_lock(&device->rx_lock); /* during pendig read request, change of config not allowed */ if (device->rx_active) { mutex_unlock(&device->rx_lock); return -EAGAIN; } if (copy_from_user(&device->rx_cfg, argp, sizeof(struct pi433_rx_cfg))) { mutex_unlock(&device->rx_lock); return -EFAULT; } mutex_unlock(&device->rx_lock); break; default: return -EINVAL; } return 0; } /*-------------------------------------------------------------------------*/ 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; } instance = kzalloc(sizeof(*instance), GFP_KERNEL); if (!instance) return -ENOMEM; /* setup instance data*/ instance->device = device; /* instance data as context */ filp->private_data = instance; stream_open(inode, filp); return 0; } static int pi433_release(struct inode *inode, struct file *filp) { struct pi433_instance *instance; instance = filp->private_data; kfree(instance); filp->private_data = NULL; return 0; } /*-------------------------------------------------------------------------*/ static int setup_gpio(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.\n", name); continue; } if (device->gpiod[i] == ERR_PTR(-EBUSY)) dev_dbg(&device->spi->dev, "%s is busy.\n", 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 */ 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); 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 successfully configured\n", name); } return 0; } static void free_gpio(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]); } } 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->spi->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 = compat_ptr_ioctl, .open = pi433_open, .release = pi433_release, .llseek = no_llseek, }; static int pi433_debugfs_regs_show(struct seq_file *m, void *p) { struct pi433_device *dev; u8 reg_data[114]; int i; char *fmt = "0x%02x, 0x%02x\n"; int ret; dev = m->private; mutex_lock(&dev->tx_fifo_lock); mutex_lock(&dev->rx_lock); // wait for on-going operations to finish ret = wait_event_interruptible(dev->rx_wait_queue, !dev->tx_active); if (ret) goto out_unlock; ret = wait_event_interruptible(dev->tx_wait_queue, !dev->rx_active); if (ret) goto out_unlock; // skip FIFO register (0x0) otherwise this can affect some of uC ops for (i = 1; i < 0x50; i++) reg_data[i] = rf69_read_reg(dev->spi, i); reg_data[REG_TESTLNA] = rf69_read_reg(dev->spi, REG_TESTLNA); reg_data[REG_TESTPA1] = rf69_read_reg(dev->spi, REG_TESTPA1); reg_data[REG_TESTPA2] = rf69_read_reg(dev->spi, REG_TESTPA2); reg_data[REG_TESTDAGC] = rf69_read_reg(dev->spi, REG_TESTDAGC); reg_data[REG_TESTAFC] = rf69_read_reg(dev->spi, REG_TESTAFC); seq_puts(m, "# reg, val\n"); for (i = 1; i < 0x50; i++) seq_printf(m, fmt, i, reg_data[i]); seq_printf(m, fmt, REG_TESTLNA, reg_data[REG_TESTLNA]); seq_printf(m, fmt, REG_TESTPA1, reg_data[REG_TESTPA1]); seq_printf(m, fmt, REG_TESTPA2, reg_data[REG_TESTPA2]); seq_printf(m, fmt, REG_TESTDAGC, reg_data[REG_TESTDAGC]); seq_printf(m, fmt, REG_TESTAFC, reg_data[REG_TESTAFC]); out_unlock: mutex_unlock(&dev->rx_lock); mutex_unlock(&dev->tx_fifo_lock); return ret; } DEFINE_SHOW_ATTRIBUTE(pi433_debugfs_regs); /*-------------------------------------------------------------------------*/ static int pi433_probe(struct spi_device *spi) { struct pi433_device *device; int retval; struct dentry *entry; /* 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\n", spi->mode, spi->bits_per_word, spi->max_speed_hz); /* read chip version */ retval = rf69_get_version(spi); if (retval < 0) return retval; switch (retval) { case 0x24: dev_dbg(&spi->dev, "found pi433 (ver. 0x%x)\n", retval); break; default: dev_dbg(&spi->dev, "unknown chip version: 0x%x\n", 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\n"); 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\n"); 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\n"); 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\n"); retval = -ENOMEM; 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\n"); goto del_cdev; } /* spi setup */ spi_set_drvdata(spi, device); entry = debugfs_create_dir(dev_name(device->dev), root_dir); debugfs_create_file("regs", 0400, entry, device, &pi433_debugfs_regs_fops); 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; } static void pi433_remove(struct spi_device *spi) { struct pi433_device *device = spi_get_drvdata(spi); debugfs_lookup_and_remove(dev_name(device->dev), root_dir); /* 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); } 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 the driver which manages those device numbers. */ status = alloc_chrdev_region(&pi433_dev, 0, N_PI433_MINORS, "pi433"); if (status < 0) return status; pi433_class = class_create("pi433"); if (IS_ERR(pi433_class)) { unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name); return PTR_ERR(pi433_class); } root_dir = debugfs_create_dir(KBUILD_MODNAME, NULL); 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); debugfs_remove(root_dir); } module_exit(pi433_exit); MODULE_AUTHOR("Marcus Wolf, <linux@wolf-entwicklungen.de>"); MODULE_DESCRIPTION("Driver for Pi433"); MODULE_LICENSE("GPL"); MODULE_ALIAS("spi:pi433"); |