/**************************************************************************** * * Driver for the IFX 6x60 spi modem. * * Copyright (C) 2008 Option International * Copyright (C) 2008 Filip Aben * Denis Joseph Barrow * Jan Dumon * * Copyright (C) 2009, 2010 Intel Corp * Russ Gorby * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA * * Driver modified by Intel from Option gtm501l_spi.c * * Notes * o The driver currently assumes a single device only. If you need to * change this then look for saved_ifx_dev and add a device lookup * o The driver is intended to be big-endian safe but has never been * tested that way (no suitable hardware). There are a couple of FIXME * notes by areas that may need addressing * o Some of the GPIO naming/setup assumptions may need revisiting if * you need to use this driver for another platform. * *****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ifx6x60.h" #define IFX_SPI_MORE_MASK 0x10 #define IFX_SPI_MORE_BIT 4 /* bit position in u8 */ #define IFX_SPI_CTS_BIT 6 /* bit position in u8 */ #define IFX_SPI_MODE SPI_MODE_1 #define IFX_SPI_TTY_ID 0 #define IFX_SPI_TIMEOUT_SEC 2 #define IFX_SPI_HEADER_0 (-1) #define IFX_SPI_HEADER_F (-2) #define PO_POST_DELAY 200 #define IFX_MDM_RST_PMU 4 /* forward reference */ static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev); static int ifx_modem_reboot_callback(struct notifier_block *nfb, unsigned long event, void *data); static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev); /* local variables */ static int spi_bpw = 16; /* 8, 16 or 32 bit word length */ static struct tty_driver *tty_drv; static struct ifx_spi_device *saved_ifx_dev; static struct lock_class_key ifx_spi_key; static struct notifier_block ifx_modem_reboot_notifier_block = { .notifier_call = ifx_modem_reboot_callback, }; static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev) { gpio_set_value(IFX_MDM_RST_PMU, 1); msleep(PO_POST_DELAY); return 0; } static int ifx_modem_reboot_callback(struct notifier_block *nfb, unsigned long event, void *data) { if (saved_ifx_dev) ifx_modem_power_off(saved_ifx_dev); else pr_warn("no ifx modem active;\n"); return NOTIFY_OK; } /* GPIO/GPE settings */ /** * mrdy_set_high - set MRDY GPIO * @ifx: device we are controlling * */ static inline void mrdy_set_high(struct ifx_spi_device *ifx) { gpio_set_value(ifx->gpio.mrdy, 1); } /** * mrdy_set_low - clear MRDY GPIO * @ifx: device we are controlling * */ static inline void mrdy_set_low(struct ifx_spi_device *ifx) { gpio_set_value(ifx->gpio.mrdy, 0); } /** * ifx_spi_power_state_set * @ifx_dev: our SPI device * @val: bits to set * * Set bit in power status and signal power system if status becomes non-0 */ static void ifx_spi_power_state_set(struct ifx_spi_device *ifx_dev, unsigned char val) { unsigned long flags; spin_lock_irqsave(&ifx_dev->power_lock, flags); /* * if power status is already non-0, just update, else * tell power system */ if (!ifx_dev->power_status) pm_runtime_get(&ifx_dev->spi_dev->dev); ifx_dev->power_status |= val; spin_unlock_irqrestore(&ifx_dev->power_lock, flags); } /** * ifx_spi_power_state_clear - clear power bit * @ifx_dev: our SPI device * @val: bits to clear * * clear bit in power status and signal power system if status becomes 0 */ static void ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val) { unsigned long flags; spin_lock_irqsave(&ifx_dev->power_lock, flags); if (ifx_dev->power_status) { ifx_dev->power_status &= ~val; if (!ifx_dev->power_status) pm_runtime_put(&ifx_dev->spi_dev->dev); } spin_unlock_irqrestore(&ifx_dev->power_lock, flags); } /** * swap_buf_8 * @buf: our buffer * @len : number of bytes (not words) in the buffer * @end: end of buffer * * Swap the contents of a buffer into big endian format */ static inline void swap_buf_8(unsigned char *buf, int len, void *end) { /* don't swap buffer if SPI word width is 8 bits */ return; } /** * swap_buf_16 * @buf: our buffer * @len : number of bytes (not words) in the buffer * @end: end of buffer * * Swap the contents of a buffer into big endian format */ static inline void swap_buf_16(unsigned char *buf, int len, void *end) { int n; u16 *buf_16 = (u16 *)buf; len = ((len + 1) >> 1); if ((void *)&buf_16[len] > end) { pr_err("swap_buf_16: swap exceeds boundary (%p > %p)!", &buf_16[len], end); return; } for (n = 0; n < len; n++) { *buf_16 = cpu_to_be16(*buf_16); buf_16++; } } /** * swap_buf_32 * @buf: our buffer * @len : number of bytes (not words) in the buffer * @end: end of buffer * * Swap the contents of a buffer into big endian format */ static inline void swap_buf_32(unsigned char *buf, int len, void *end) { int n; u32 *buf_32 = (u32 *)buf; len = (len + 3) >> 2; if ((void *)&buf_32[len] > end) { pr_err("swap_buf_32: swap exceeds boundary (%p > %p)!\n", &buf_32[len], end); return; } for (n = 0; n < len; n++) { *buf_32 = cpu_to_be32(*buf_32); buf_32++; } } /** * mrdy_assert - assert MRDY line * @ifx_dev: our SPI device * * Assert mrdy and set timer to wait for SRDY interrupt, if SRDY is low * now. * * FIXME: Can SRDY even go high as we are running this code ? */ static void mrdy_assert(struct ifx_spi_device *ifx_dev) { int val = gpio_get_value(ifx_dev->gpio.srdy); if (!val) { if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) { mod_timer(&ifx_dev->spi_timer,jiffies + IFX_SPI_TIMEOUT_SEC*HZ); } } ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_DATA_PENDING); mrdy_set_high(ifx_dev); } /** * ifx_spi_timeout - SPI timeout * @arg: our SPI device * * The SPI has timed out: hang up the tty. Users will then see a hangup * and error events. */ static void ifx_spi_timeout(unsigned long arg) { struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *)arg; dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***"); tty_port_tty_hangup(&ifx_dev->tty_port, false); mrdy_set_low(ifx_dev); clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags); } /* char/tty operations */ /** * ifx_spi_tiocmget - get modem lines * @tty: our tty device * @filp: file handle issuing the request * * Map the signal state into Linux modem flags and report the value * in Linux terms */ static int ifx_spi_tiocmget(struct tty_struct *tty) { unsigned int value; struct ifx_spi_device *ifx_dev = tty->driver_data; value = (test_bit(IFX_SPI_RTS, &ifx_dev->signal_state) ? TIOCM_RTS : 0) | (test_bit(IFX_SPI_DTR, &ifx_dev->signal_state) ? TIOCM_DTR : 0) | (test_bit(IFX_SPI_CTS, &ifx_dev->signal_state) ? TIOCM_CTS : 0) | (test_bit(IFX_SPI_DSR, &ifx_dev->signal_state) ? TIOCM_DSR : 0) | (test_bit(IFX_SPI_DCD, &ifx_dev->signal_state) ? TIOCM_CAR : 0) | (test_bit(IFX_SPI_RI, &ifx_dev->signal_state) ? TIOCM_RNG : 0); return value; } /** * ifx_spi_tiocmset - set modem bits * @tty: the tty structure * @set: bits to set * @clear: bits to clear * * The IFX6x60 only supports DTR and RTS. Set them accordingly * and flag that an update to the modem is needed. * * FIXME: do we need to kick the tranfers when we do this ? */ static int ifx_spi_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) { struct ifx_spi_device *ifx_dev = tty->driver_data; if (set & TIOCM_RTS) set_bit(IFX_SPI_RTS, &ifx_dev->signal_state); if (set & TIOCM_DTR) set_bit(IFX_SPI_DTR, &ifx_dev->signal_state); if (clear & TIOCM_RTS) clear_bit(IFX_SPI_RTS, &ifx_dev->signal_state); if (clear & TIOCM_DTR) clear_bit(IFX_SPI_DTR, &ifx_dev->signal_state); set_bit(IFX_SPI_UPDATE, &ifx_dev->signal_state); return 0; } /** * ifx_spi_open - called on tty open * @tty: our tty device * @filp: file handle being associated with the tty * * Open the tty interface. We let the tty_port layer do all the work * for us. * * FIXME: Remove single device assumption and saved_ifx_dev */ static int ifx_spi_open(struct tty_struct *tty, struct file *filp) { return tty_port_open(&saved_ifx_dev->tty_port, tty, filp); } /** * ifx_spi_close - called when our tty closes * @tty: the tty being closed * @filp: the file handle being closed * * Perform the close of the tty. We use the tty_port layer to do all * our hard work. */ static void ifx_spi_close(struct tty_struct *tty, struct file *filp) { struct ifx_spi_device *ifx_dev = tty->driver_data; tty_port_close(&ifx_dev->tty_port, tty, filp); /* FIXME: should we do an ifx_spi_reset here ? */ } /** * ifx_decode_spi_header - decode received header * @buffer: the received data * @length: decoded length * @more: decoded more flag * @received_cts: status of cts we received * * Note how received_cts is handled -- if header is all F it is left * the same as it was, if header is all 0 it is set to 0 otherwise it is * taken from the incoming header. * * FIXME: endianness */ static int ifx_spi_decode_spi_header(unsigned char *buffer, int *length, unsigned char *more, unsigned char *received_cts) { u16 h1; u16 h2; u16 *in_buffer = (u16 *)buffer; h1 = *in_buffer; h2 = *(in_buffer+1); if (h1 == 0 && h2 == 0) { *received_cts = 0; return IFX_SPI_HEADER_0; } else if (h1 == 0xffff && h2 == 0xffff) { /* spi_slave_cts remains as it was */ return IFX_SPI_HEADER_F; } *length = h1 & 0xfff; /* upper bits of byte are flags */ *more = (buffer[1] >> IFX_SPI_MORE_BIT) & 1; *received_cts = (buffer[3] >> IFX_SPI_CTS_BIT) & 1; return 0; } /** * ifx_setup_spi_header - set header fields * @txbuffer: pointer to start of SPI buffer * @tx_count: bytes * @more: indicate if more to follow * * Format up an SPI header for a transfer * * FIXME: endianness? */ static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count, unsigned char more) { *(u16 *)(txbuffer) = tx_count; *(u16 *)(txbuffer+2) = IFX_SPI_PAYLOAD_SIZE; txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK; } /** * ifx_spi_prepare_tx_buffer - prepare transmit frame * @ifx_dev: our SPI device * * The transmit buffr needs a header and various other bits of * information followed by as much data as we can pull from the FIFO * and transfer. This function formats up a suitable buffer in the * ifx_dev->tx_buffer * * FIXME: performance - should we wake the tty when the queue is half * empty ? */ static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev) { int temp_count; int queue_length; int tx_count; unsigned char *tx_buffer; tx_buffer = ifx_dev->tx_buffer; /* make room for required SPI header */ tx_buffer += IFX_SPI_HEADER_OVERHEAD; tx_count = IFX_SPI_HEADER_OVERHEAD; /* clear to signal no more data if this turns out to be the * last buffer sent in a sequence */ ifx_dev->spi_more = 0; /* if modem cts is set, just send empty buffer */ if (!ifx_dev->spi_slave_cts) { /* see if there's tx data */ queue_length = kfifo_len(&ifx_dev->tx_fifo); if (queue_length != 0) { /* data to mux -- see if there's room for it */ temp_count = min(queue_length, IFX_SPI_PAYLOAD_SIZE); temp_count = kfifo_out_locked(&ifx_dev->tx_fifo, tx_buffer, temp_count, &ifx_dev->fifo_lock); /* update buffer pointer and data count in message */ tx_buffer += temp_count; tx_count += temp_count; if (temp_count == queue_length) /* poke port to get more data */ tty_port_tty_wakeup(&ifx_dev->tty_port); else /* more data in port, use next SPI message */ ifx_dev->spi_more = 1; } } /* have data and info for header -- set up SPI header in buffer */ /* spi header needs payload size, not entire buffer size */ ifx_spi_setup_spi_header(ifx_dev->tx_buffer, tx_count-IFX_SPI_HEADER_OVERHEAD, ifx_dev->spi_more); /* swap actual data in the buffer */ ifx_dev->swap_buf((ifx_dev->tx_buffer), tx_count, &ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]); return tx_count; } /** * ifx_spi_write - line discipline write * @tty: our tty device * @buf: pointer to buffer to write (kernel space) * @count: size of buffer * * Write the characters we have been given into the FIFO. If the device * is not active then activate it, when the SRDY line is asserted back * this will commence I/O */ static int ifx_spi_write(struct tty_struct *tty, const unsigned char *buf, int count) { struct ifx_spi_device *ifx_dev = tty->driver_data; unsigned char *tmp_buf = (unsigned char *)buf; unsigned long flags; bool is_fifo_empty; int tx_count; spin_lock_irqsave(&ifx_dev->fifo_lock, flags); is_fifo_empty = kfifo_is_empty(&ifx_dev->tx_fifo); tx_count = kfifo_in(&ifx_dev->tx_fifo, tmp_buf, count); spin_unlock_irqrestore(&ifx_dev->fifo_lock, flags); if (is_fifo_empty) mrdy_assert(ifx_dev); return tx_count; } /** * ifx_spi_chars_in_buffer - line discipline helper * @tty: our tty device * * Report how much data we can accept before we drop bytes. As we use * a simple FIFO this is nice and easy. */ static int ifx_spi_write_room(struct tty_struct *tty) { struct ifx_spi_device *ifx_dev = tty->driver_data; return IFX_SPI_FIFO_SIZE - kfifo_len(&ifx_dev->tx_fifo); } /** * ifx_spi_chars_in_buffer - line discipline helper * @tty: our tty device * * Report how many characters we have buffered. In our case this is the * number of bytes sitting in our transmit FIFO. */ static int ifx_spi_chars_in_buffer(struct tty_struct *tty) { struct ifx_spi_device *ifx_dev = tty->driver_data; return kfifo_len(&ifx_dev->tx_fifo); } /** * ifx_port_hangup * @port: our tty port * * tty port hang up. Called when tty_hangup processing is invoked either * by loss of carrier, or by software (eg vhangup). Serialized against * activate/shutdown by the tty layer. */ static void ifx_spi_hangup(struct tty_struct *tty) { struct ifx_spi_device *ifx_dev = tty->driver_data; tty_port_hangup(&ifx_dev->tty_port); } /** * ifx_port_activate * @port: our tty port * * tty port activate method - called for first open. Serialized * with hangup and shutdown by the tty layer. */ static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty) { struct ifx_spi_device *ifx_dev = container_of(port, struct ifx_spi_device, tty_port); /* clear any old data; can't do this in 'close' */ kfifo_reset(&ifx_dev->tx_fifo); /* clear any flag which may be set in port shutdown procedure */ clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags); clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags); /* put port data into this tty */ tty->driver_data = ifx_dev; /* allows flip string push from int context */ port->low_latency = 1; /* set flag to allows data transfer */ set_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags); return 0; } /** * ifx_port_shutdown * @port: our tty port * * tty port shutdown method - called for last port close. Serialized * with hangup and activate by the tty layer. */ static void ifx_port_shutdown(struct tty_port *port) { struct ifx_spi_device *ifx_dev = container_of(port, struct ifx_spi_device, tty_port); clear_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags); mrdy_set_low(ifx_dev); del_timer(&ifx_dev->spi_timer); clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags); tasklet_kill(&ifx_dev->io_work_tasklet); } static const struct tty_port_operations ifx_tty_port_ops = { .activate = ifx_port_activate, .shutdown = ifx_port_shutdown, }; static const struct tty_operations ifx_spi_serial_ops = { .open = ifx_spi_open, .close = ifx_spi_close, .write = ifx_spi_write, .hangup = ifx_spi_hangup, .write_room = ifx_spi_write_room, .chars_in_buffer = ifx_spi_chars_in_buffer, .tiocmget = ifx_spi_tiocmget, .tiocmset = ifx_spi_tiocmset, }; /** * ifx_spi_insert_fip_string - queue received data * @ifx_ser: our SPI device * @chars: buffer we have received * @size: number of chars reeived * * Queue bytes to the tty assuming the tty side is currently open. If * not the discard the data. */ static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev, unsigned char *chars, size_t size) { tty_insert_flip_string(&ifx_dev->tty_port, chars, size); tty_flip_buffer_push(&ifx_dev->tty_port); } /** * ifx_spi_complete - SPI transfer completed * @ctx: our SPI device * * An SPI transfer has completed. Process any received data and kick off * any further transmits we can commence. */ static void ifx_spi_complete(void *ctx) { struct ifx_spi_device *ifx_dev = ctx; int length; int actual_length; unsigned char more; unsigned char cts; int local_write_pending = 0; int queue_length; int srdy; int decode_result; mrdy_set_low(ifx_dev); if (!ifx_dev->spi_msg.status) { /* check header validity, get comm flags */ ifx_dev->swap_buf(ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD, &ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]); decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer, &length, &more, &cts); if (decode_result == IFX_SPI_HEADER_0) { dev_dbg(&ifx_dev->spi_dev->dev, "ignore input: invalid header 0"); ifx_dev->spi_slave_cts = 0; goto complete_exit; } else if (decode_result == IFX_SPI_HEADER_F) { dev_dbg(&ifx_dev->spi_dev->dev, "ignore input: invalid header F"); goto complete_exit; } ifx_dev->spi_slave_cts = cts; actual_length = min((unsigned int)length, ifx_dev->spi_msg.actual_length); ifx_dev->swap_buf( (ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD), actual_length, &ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]); ifx_spi_insert_flip_string( ifx_dev, ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD, (size_t)actual_length); } else { dev_dbg(&ifx_dev->spi_dev->dev, "SPI transfer error %d", ifx_dev->spi_msg.status); } complete_exit: if (ifx_dev->write_pending) { ifx_dev->write_pending = 0; local_write_pending = 1; } clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags)); queue_length = kfifo_len(&ifx_dev->tx_fifo); srdy = gpio_get_value(ifx_dev->gpio.srdy); if (!srdy) ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY); /* schedule output if there is more to do */ if (test_and_clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags)) tasklet_schedule(&ifx_dev->io_work_tasklet); else { if (more || ifx_dev->spi_more || queue_length > 0 || local_write_pending) { if (ifx_dev->spi_slave_cts) { if (more) mrdy_assert(ifx_dev); } else mrdy_assert(ifx_dev); } else { /* * poke line discipline driver if any for more data * may or may not get more data to write * for now, say not busy */ ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_DATA_PENDING); tty_port_tty_wakeup(&ifx_dev->tty_port); } } } /** * ifx_spio_io - I/O tasklet * @data: our SPI device * * Queue data for transmission if possible and then kick off the * transfer. */ static void ifx_spi_io(unsigned long data) { int retval; struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *) data; if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags) && test_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags)) { if (ifx_dev->gpio.unack_srdy_int_nb > 0) ifx_dev->gpio.unack_srdy_int_nb--; ifx_spi_prepare_tx_buffer(ifx_dev); spi_message_init(&ifx_dev->spi_msg); INIT_LIST_HEAD(&ifx_dev->spi_msg.queue); ifx_dev->spi_msg.context = ifx_dev; ifx_dev->spi_msg.complete = ifx_spi_complete; /* set up our spi transfer */ /* note len is BYTES, not transfers */ ifx_dev->spi_xfer.len = IFX_SPI_TRANSFER_SIZE; ifx_dev->spi_xfer.cs_change = 0; ifx_dev->spi_xfer.speed_hz = ifx_dev->spi_dev->max_speed_hz; /* ifx_dev->spi_xfer.speed_hz = 390625; */ ifx_dev->spi_xfer.bits_per_word = ifx_dev->spi_dev->bits_per_word; ifx_dev->spi_xfer.tx_buf = ifx_dev->tx_buffer; ifx_dev->spi_xfer.rx_buf = ifx_dev->rx_buffer; /* * setup dma pointers */ if (ifx_dev->use_dma) { ifx_dev->spi_msg.is_dma_mapped = 1; ifx_dev->tx_dma = ifx_dev->tx_bus; ifx_dev->rx_dma = ifx_dev->rx_bus; ifx_dev->spi_xfer.tx_dma = ifx_dev->tx_dma; ifx_dev->spi_xfer.rx_dma = ifx_dev->rx_dma; } else { ifx_dev->spi_msg.is_dma_mapped = 0; ifx_dev->tx_dma = (dma_addr_t)0; ifx_dev->rx_dma = (dma_addr_t)0; ifx_dev->spi_xfer.tx_dma = (dma_addr_t)0; ifx_dev->spi_xfer.rx_dma = (dma_addr_t)0; } spi_message_add_tail(&ifx_dev->spi_xfer, &ifx_dev->spi_msg); /* Assert MRDY. This may have already been done by the write * routine. */ mrdy_assert(ifx_dev); retval = spi_async(ifx_dev->spi_dev, &ifx_dev->spi_msg); if (retval) { clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags); tasklet_schedule(&ifx_dev->io_work_tasklet); return; } } else ifx_dev->write_pending = 1; } /** * ifx_spi_free_port - free up the tty side * @ifx_dev: IFX device going away * * Unregister and free up a port when the device goes away */ static void ifx_spi_free_port(struct ifx_spi_device *ifx_dev) { if (ifx_dev->tty_dev) tty_unregister_device(tty_drv, ifx_dev->minor); tty_port_destroy(&ifx_dev->tty_port); kfifo_free(&ifx_dev->tx_fifo); } /** * ifx_spi_create_port - create a new port * @ifx_dev: our spi device * * Allocate and initialise the tty port that goes with this interface * and add it to the tty layer so that it can be opened. */ static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev) { int ret = 0; struct tty_port *pport = &ifx_dev->tty_port; spin_lock_init(&ifx_dev->fifo_lock); lockdep_set_class_and_subclass(&ifx_dev->fifo_lock, &ifx_spi_key, 0); if (kfifo_alloc(&ifx_dev->tx_fifo, IFX_SPI_FIFO_SIZE, GFP_KERNEL)) { ret = -ENOMEM; goto error_ret; } tty_port_init(pport); pport->ops = &ifx_tty_port_ops; ifx_dev->minor = IFX_SPI_TTY_ID; ifx_dev->tty_dev = tty_port_register_device(pport, tty_drv, ifx_dev->minor, &ifx_dev->spi_dev->dev); if (IS_ERR(ifx_dev->tty_dev)) { dev_dbg(&ifx_dev->spi_dev->dev, "%s: registering tty device failed", __func__); ret = PTR_ERR(ifx_dev->tty_dev); goto error_port; } return 0; error_port: tty_port_destroy(pport); error_ret: ifx_spi_free_port(ifx_dev); return ret; } /** * ifx_spi_handle_srdy - handle SRDY * @ifx_dev: device asserting SRDY * * Check our device state and see what we need to kick off when SRDY * is asserted. This usually means killing the timer and firing off the * I/O processing. */ static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev) { if (test_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) { del_timer(&ifx_dev->spi_timer); clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags); } ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_SRDY); if (!test_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags)) tasklet_schedule(&ifx_dev->io_work_tasklet); else set_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags); } /** * ifx_spi_srdy_interrupt - SRDY asserted * @irq: our IRQ number * @dev: our ifx device * * The modem asserted SRDY. Handle the srdy event */ static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev) { struct ifx_spi_device *ifx_dev = dev; ifx_dev->gpio.unack_srdy_int_nb++; ifx_spi_handle_srdy(ifx_dev); return IRQ_HANDLED; } /** * ifx_spi_reset_interrupt - Modem has changed reset state * @irq: interrupt number * @dev: our device pointer * * The modem has either entered or left reset state. Check the GPIO * line to see which. * * FIXME: review locking on MR_INPROGRESS versus * parallel unsolicited reset/solicited reset */ static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev) { struct ifx_spi_device *ifx_dev = dev; int val = gpio_get_value(ifx_dev->gpio.reset_out); int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state); if (val == 0) { /* entered reset */ set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state); if (!solreset) { /* unsolicited reset */ tty_port_tty_hangup(&ifx_dev->tty_port, false); } } else { /* exited reset */ clear_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state); if (solreset) { set_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state); wake_up(&ifx_dev->mdm_reset_wait); } } return IRQ_HANDLED; } /** * ifx_spi_free_device - free device * @ifx_dev: device to free * * Free the IFX device */ static void ifx_spi_free_device(struct ifx_spi_device *ifx_dev) { ifx_spi_free_port(ifx_dev); dma_free_coherent(&ifx_dev->spi_dev->dev, IFX_SPI_TRANSFER_SIZE, ifx_dev->tx_buffer, ifx_dev->tx_bus); dma_free_coherent(&ifx_dev->spi_dev->dev, IFX_SPI_TRANSFER_SIZE, ifx_dev->rx_buffer, ifx_dev->rx_bus); } /** * ifx_spi_reset - reset modem * @ifx_dev: modem to reset * * Perform a reset on the modem */ static int ifx_spi_reset(struct ifx_spi_device *ifx_dev) { int ret; /* * set up modem power, reset * * delays are required on some platforms for the modem * to reset properly */ set_bit(MR_START, &ifx_dev->mdm_reset_state); gpio_set_value(ifx_dev->gpio.po, 0); gpio_set_value(ifx_dev->gpio.reset, 0); msleep(25); gpio_set_value(ifx_dev->gpio.reset, 1); msleep(1); gpio_set_value(ifx_dev->gpio.po, 1); msleep(1); gpio_set_value(ifx_dev->gpio.po, 0); ret = wait_event_timeout(ifx_dev->mdm_reset_wait, test_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state), IFX_RESET_TIMEOUT); if (!ret) dev_warn(&ifx_dev->spi_dev->dev, "Modem reset timeout: (state:%lx)", ifx_dev->mdm_reset_state); ifx_dev->mdm_reset_state = 0; return ret; } /** * ifx_spi_spi_probe - probe callback * @spi: our possible matching SPI device * * Probe for a 6x60 modem on SPI bus. Perform any needed device and * GPIO setup. * * FIXME: * - Support for multiple devices * - Split out MID specific GPIO handling eventually */ static int ifx_spi_spi_probe(struct spi_device *spi) { int ret; int srdy; struct ifx_modem_platform_data *pl_data; struct ifx_spi_device *ifx_dev; if (saved_ifx_dev) { dev_dbg(&spi->dev, "ignoring subsequent detection"); return -ENODEV; } pl_data = (struct ifx_modem_platform_data *)spi->dev.platform_data; if (!pl_data) { dev_err(&spi->dev, "missing platform data!"); return -ENODEV; } /* initialize structure to hold our device variables */ ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL); if (!ifx_dev) { dev_err(&spi->dev, "spi device allocation failed"); return -ENOMEM; } saved_ifx_dev = ifx_dev; ifx_dev->spi_dev = spi; clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags); spin_lock_init(&ifx_dev->write_lock); spin_lock_init(&ifx_dev->power_lock); ifx_dev->power_status = 0; init_timer(&ifx_dev->spi_timer); ifx_dev->spi_timer.function = ifx_spi_timeout; ifx_dev->spi_timer.data = (unsigned long)ifx_dev; ifx_dev->modem = pl_data->modem_type; ifx_dev->use_dma = pl_data->use_dma; ifx_dev->max_hz = pl_data->max_hz; /* initialize spi mode, etc */ spi->max_speed_hz = ifx_dev->max_hz; spi->mode = IFX_SPI_MODE | (SPI_LOOP & spi->mode); spi->bits_per_word = spi_bpw; ret = spi_setup(spi); if (ret) { dev_err(&spi->dev, "SPI setup wasn't successful %d", ret); return -ENODEV; } /* init swap_buf function according to word width configuration */ if (spi->bits_per_word == 32) ifx_dev->swap_buf = swap_buf_32; else if (spi->bits_per_word == 16) ifx_dev->swap_buf = swap_buf_16; else ifx_dev->swap_buf = swap_buf_8; /* ensure SPI protocol flags are initialized to enable transfer */ ifx_dev->spi_more = 0; ifx_dev->spi_slave_cts = 0; /*initialize transfer and dma buffers */ ifx_dev->tx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent, IFX_SPI_TRANSFER_SIZE, &ifx_dev->tx_bus, GFP_KERNEL); if (!ifx_dev->tx_buffer) { dev_err(&spi->dev, "DMA-TX buffer allocation failed"); ret = -ENOMEM; goto error_ret; } ifx_dev->rx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent, IFX_SPI_TRANSFER_SIZE, &ifx_dev->rx_bus, GFP_KERNEL); if (!ifx_dev->rx_buffer) { dev_err(&spi->dev, "DMA-RX buffer allocation failed"); ret = -ENOMEM; goto error_ret; } /* initialize waitq for modem reset */ init_waitqueue_head(&ifx_dev->mdm_reset_wait); spi_set_drvdata(spi, ifx_dev); tasklet_init(&ifx_dev->io_work_tasklet, ifx_spi_io, (unsigned long)ifx_dev); set_bit(IFX_SPI_STATE_PRESENT, &ifx_dev->flags); /* create our tty port */ ret = ifx_spi_create_port(ifx_dev); if (ret != 0) { dev_err(&spi->dev, "create default tty port failed"); goto error_ret; } ifx_dev->gpio.reset = pl_data->rst_pmu; ifx_dev->gpio.po = pl_data->pwr_on; ifx_dev->gpio.mrdy = pl_data->mrdy; ifx_dev->gpio.srdy = pl_data->srdy; ifx_dev->gpio.reset_out = pl_data->rst_out; dev_info(&spi->dev, "gpios %d, %d, %d, %d, %d", ifx_dev->gpio.reset, ifx_dev->gpio.po, ifx_dev->gpio.mrdy, ifx_dev->gpio.srdy, ifx_dev->gpio.reset_out); /* Configure gpios */ ret = gpio_request(ifx_dev->gpio.reset, "ifxModem"); if (ret < 0) { dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET)", ifx_dev->gpio.reset); goto error_ret; } ret += gpio_direction_output(ifx_dev->gpio.reset, 0); ret += gpio_export(ifx_dev->gpio.reset, 1); if (ret) { dev_err(&spi->dev, "Unable to configure GPIO%d (RESET)", ifx_dev->gpio.reset); ret = -EBUSY; goto error_ret2; } ret = gpio_request(ifx_dev->gpio.po, "ifxModem"); ret += gpio_direction_output(ifx_dev->gpio.po, 0); ret += gpio_export(ifx_dev->gpio.po, 1); if (ret) { dev_err(&spi->dev, "Unable to configure GPIO%d (ON)", ifx_dev->gpio.po); ret = -EBUSY; goto error_ret3; } ret = gpio_request(ifx_dev->gpio.mrdy, "ifxModem"); if (ret < 0) { dev_err(&spi->dev, "Unable to allocate GPIO%d (MRDY)", ifx_dev->gpio.mrdy); goto error_ret3; } ret += gpio_export(ifx_dev->gpio.mrdy, 1); ret += gpio_direction_output(ifx_dev->gpio.mrdy, 0); if (ret) { dev_err(&spi->dev, "Unable to configure GPIO%d (MRDY)", ifx_dev->gpio.mrdy); ret = -EBUSY; goto error_ret4; } ret = gpio_request(ifx_dev->gpio.srdy, "ifxModem"); if (ret < 0) { dev_err(&spi->dev, "Unable to allocate GPIO%d (SRDY)", ifx_dev->gpio.srdy); ret = -EBUSY; goto error_ret4; } ret += gpio_export(ifx_dev->gpio.srdy, 1); ret += gpio_direction_input(ifx_dev->gpio.srdy); if (ret) { dev_err(&spi->dev, "Unable to configure GPIO%d (SRDY)", ifx_dev->gpio.srdy); ret = -EBUSY; goto error_ret5; } ret = gpio_request(ifx_dev->gpio.reset_out, "ifxModem"); if (ret < 0) { dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET_OUT)", ifx_dev->gpio.reset_out); goto error_ret5; } ret += gpio_export(ifx_dev->gpio.reset_out, 1); ret += gpio_direction_input(ifx_dev->gpio.reset_out); if (ret) { dev_err(&spi->dev, "Unable to configure GPIO%d (RESET_OUT)", ifx_dev->gpio.reset_out); ret = -EBUSY; goto error_ret6; } ret = request_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_spi_reset_interrupt, IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME, (void *)ifx_dev); if (ret) { dev_err(&spi->dev, "Unable to get irq %x\n", gpio_to_irq(ifx_dev->gpio.reset_out)); goto error_ret6; } ret = ifx_spi_reset(ifx_dev); ret = request_irq(gpio_to_irq(ifx_dev->gpio.srdy), ifx_spi_srdy_interrupt, IRQF_TRIGGER_RISING, DRVNAME, (void *)ifx_dev); if (ret) { dev_err(&spi->dev, "Unable to get irq %x", gpio_to_irq(ifx_dev->gpio.srdy)); goto error_ret7; } /* set pm runtime power state and register with power system */ pm_runtime_set_active(&spi->dev); pm_runtime_enable(&spi->dev); /* handle case that modem is already signaling SRDY */ /* no outgoing tty open at this point, this just satisfies the * modem's read and should reset communication properly */ srdy = gpio_get_value(ifx_dev->gpio.srdy); if (srdy) { mrdy_assert(ifx_dev); ifx_spi_handle_srdy(ifx_dev); } else mrdy_set_low(ifx_dev); return 0; error_ret7: free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev); error_ret6: gpio_free(ifx_dev->gpio.srdy); error_ret5: gpio_free(ifx_dev->gpio.mrdy); error_ret4: gpio_free(ifx_dev->gpio.reset); error_ret3: gpio_free(ifx_dev->gpio.po); error_ret2: gpio_free(ifx_dev->gpio.reset_out); error_ret: ifx_spi_free_device(ifx_dev); saved_ifx_dev = NULL; return ret; } /** * ifx_spi_spi_remove - SPI device was removed * @spi: SPI device * * FIXME: We should be shutting the device down here not in * the module unload path. */ static int ifx_spi_spi_remove(struct spi_device *spi) { struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi); /* stop activity */ tasklet_kill(&ifx_dev->io_work_tasklet); /* free irq */ free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev); free_irq(gpio_to_irq(ifx_dev->gpio.srdy), (void *)ifx_dev); gpio_free(ifx_dev->gpio.srdy); gpio_free(ifx_dev->gpio.mrdy); gpio_free(ifx_dev->gpio.reset); gpio_free(ifx_dev->gpio.po); gpio_free(ifx_dev->gpio.reset_out); /* free allocations */ ifx_spi_free_device(ifx_dev); saved_ifx_dev = NULL; return 0; } /** * ifx_spi_spi_shutdown - called on SPI shutdown * @spi: SPI device * * No action needs to be taken here */ static void ifx_spi_spi_shutdown(struct spi_device *spi) { struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi); ifx_modem_power_off(ifx_dev); } /* * various suspends and resumes have nothing to do * no hardware to save state for */ /** * ifx_spi_pm_suspend - suspend modem on system suspend * @dev: device being suspended * * Suspend the modem. No action needed on Intel MID platforms, may * need extending for other systems. */ static int ifx_spi_pm_suspend(struct device *dev) { return 0; } /** * ifx_spi_pm_resume - resume modem on system resume * @dev: device being suspended * * Allow the modem to resume. No action needed. * * FIXME: do we need to reset anything here ? */ static int ifx_spi_pm_resume(struct device *dev) { return 0; } /** * ifx_spi_pm_runtime_resume - suspend modem * @dev: device being suspended * * Allow the modem to resume. No action needed. */ static int ifx_spi_pm_runtime_resume(struct device *dev) { return 0; } /** * ifx_spi_pm_runtime_suspend - suspend modem * @dev: device being suspended * * Allow the modem to suspend and thus suspend to continue up the * device tree. */ static int ifx_spi_pm_runtime_suspend(struct device *dev) { return 0; } /** * ifx_spi_pm_runtime_idle - check if modem idle * @dev: our device * * Check conditions and queue runtime suspend if idle. */ static int ifx_spi_pm_runtime_idle(struct device *dev) { struct spi_device *spi = to_spi_device(dev); struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi); if (!ifx_dev->power_status) pm_runtime_suspend(dev); return 0; } static const struct dev_pm_ops ifx_spi_pm = { .resume = ifx_spi_pm_resume, .suspend = ifx_spi_pm_suspend, .runtime_resume = ifx_spi_pm_runtime_resume, .runtime_suspend = ifx_spi_pm_runtime_suspend, .runtime_idle = ifx_spi_pm_runtime_idle }; static const struct spi_device_id ifx_id_table[] = { {"ifx6160", 0}, {"ifx6260", 0}, { } }; MODULE_DEVICE_TABLE(spi, ifx_id_table); /* spi operations */ static struct spi_driver ifx_spi_driver = { .driver = { .name = DRVNAME, .pm = &ifx_spi_pm, .owner = THIS_MODULE}, .probe = ifx_spi_spi_probe, .shutdown = ifx_spi_spi_shutdown, .remove = ifx_spi_spi_remove, .id_table = ifx_id_table }; /** * ifx_spi_exit - module exit * * Unload the module. */ static void __exit ifx_spi_exit(void) { /* unregister */ tty_unregister_driver(tty_drv); put_tty_driver(tty_drv); spi_unregister_driver((void *)&ifx_spi_driver); unregister_reboot_notifier(&ifx_modem_reboot_notifier_block); } /** * ifx_spi_init - module entry point * * Initialise the SPI and tty interfaces for the IFX SPI driver * We need to initialize upper-edge spi driver after the tty * driver because otherwise the spi probe will race */ static int __init ifx_spi_init(void) { int result; tty_drv = alloc_tty_driver(1); if (!tty_drv) { pr_err("%s: alloc_tty_driver failed", DRVNAME); return -ENOMEM; } tty_drv->driver_name = DRVNAME; tty_drv->name = TTYNAME; tty_drv->minor_start = IFX_SPI_TTY_ID; tty_drv->type = TTY_DRIVER_TYPE_SERIAL; tty_drv->subtype = SERIAL_TYPE_NORMAL; tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; tty_drv->init_termios = tty_std_termios; tty_set_operations(tty_drv, &ifx_spi_serial_ops); result = tty_register_driver(tty_drv); if (result) { pr_err("%s: tty_register_driver failed(%d)", DRVNAME, result); goto err_free_tty; } result = spi_register_driver((void *)&ifx_spi_driver); if (result) { pr_err("%s: spi_register_driver failed(%d)", DRVNAME, result); goto err_unreg_tty; } result = register_reboot_notifier(&ifx_modem_reboot_notifier_block); if (result) { pr_err("%s: register ifx modem reboot notifier failed(%d)", DRVNAME, result); goto err_unreg_spi; } return 0; err_unreg_spi: spi_unregister_driver((void *)&ifx_spi_driver); err_unreg_tty: tty_unregister_driver(tty_drv); err_free_tty: put_tty_driver(tty_drv); return result; } module_init(ifx_spi_init); module_exit(ifx_spi_exit); MODULE_AUTHOR("Intel"); MODULE_DESCRIPTION("IFX6x60 spi driver"); MODULE_LICENSE("GPL"); MODULE_INFO(Version, "0.1-IFX6x60");