diff options
Diffstat (limited to 'drivers/tty/serial/ifx6x60.c')
| -rw-r--r-- | drivers/tty/serial/ifx6x60.c | 1389 |
1 files changed, 1389 insertions, 0 deletions
diff --git a/drivers/tty/serial/ifx6x60.c b/drivers/tty/serial/ifx6x60.c new file mode 100644 index 000000000..21d519c80 --- /dev/null +++ b/drivers/tty/serial/ifx6x60.c @@ -0,0 +1,1389 @@ +// SPDX-License-Identifier: GPL-2.0 +/**************************************************************************** + * + * Driver for the IFX 6x60 spi modem. + * + * Copyright (C) 2008 Option International + * Copyright (C) 2008 Filip Aben <f.aben@option.com> + * Denis Joseph Barrow <d.barow@option.com> + * Jan Dumon <j.dumon@option.com> + * + * Copyright (C) 2009, 2010 Intel Corp + * Russ Gorby <russ.gorby@intel.com> + * + * 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 <linux/dma-mapping.h> +#include <linux/module.h> +#include <linux/termios.h> +#include <linux/tty.h> +#include <linux/device.h> +#include <linux/spi/spi.h> +#include <linux/kfifo.h> +#include <linux/tty_flip.h> +#include <linux/timer.h> +#include <linux/serial.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/rfkill.h> +#include <linux/fs.h> +#include <linux/ip.h> +#include <linux/dmapool.h> +#include <linux/gpio/consumer.h> +#include <linux/sched.h> +#include <linux/time.h> +#include <linux/wait.h> +#include <linux/pm.h> +#include <linux/pm_runtime.h> +#include <linux/spi/ifx_modem.h> +#include <linux/delay.h> +#include <linux/reboot.h> + +#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 + +/* 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) +{ + gpiod_set_value(ifx_dev->gpio.pmu_reset, 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) +{ + gpiod_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) +{ + gpiod_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 = gpiod_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 + * @t: timer in 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(struct timer_list *t) +{ + struct ifx_spi_device *ifx_dev = from_timer(ifx_dev, t, spi_timer); + + 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 + * + * 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; + *more = 0; + return IFX_SPI_HEADER_0; + } else if (h1 == 0xffff && h2 == 0xffff) { + *more = 0; + /* 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 + * @tty: our tty + * + * 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_dev: 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 = 0; + 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 { + more = 0; + 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 = gpiod_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(struct tasklet_struct *t) +{ + int retval; + struct ifx_spi_device *ifx_dev = from_tasklet(ifx_dev, t, + io_work_tasklet); + + 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 = gpiod_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); + gpiod_set_value(ifx_dev->gpio.po, 0); + gpiod_set_value(ifx_dev->gpio.reset, 0); + msleep(25); + gpiod_set_value(ifx_dev->gpio.reset, 1); + msleep(1); + gpiod_set_value(ifx_dev->gpio.po, 1); + msleep(1); + gpiod_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; + struct device *dev = &spi->dev; + + if (saved_ifx_dev) { + dev_dbg(dev, "ignoring subsequent detection"); + return -ENODEV; + } + + pl_data = dev_get_platdata(dev); + if (!pl_data) { + dev_err(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(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; + timer_setup(&ifx_dev->spi_timer, ifx_spi_timeout, 0); + 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(dev, "SPI setup wasn't successful %d", ret); + kfree(ifx_dev); + 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(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(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_setup(&ifx_dev->io_work_tasklet, ifx_spi_io); + + 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(dev, "create default tty port failed"); + goto error_ret; + } + + ifx_dev->gpio.reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(ifx_dev->gpio.reset)) { + dev_err(dev, "could not obtain reset GPIO\n"); + ret = PTR_ERR(ifx_dev->gpio.reset); + goto error_ret; + } + gpiod_set_consumer_name(ifx_dev->gpio.reset, "ifxModem reset"); + ifx_dev->gpio.po = devm_gpiod_get(dev, "power", GPIOD_OUT_LOW); + if (IS_ERR(ifx_dev->gpio.po)) { + dev_err(dev, "could not obtain power GPIO\n"); + ret = PTR_ERR(ifx_dev->gpio.po); + goto error_ret; + } + gpiod_set_consumer_name(ifx_dev->gpio.po, "ifxModem power"); + ifx_dev->gpio.mrdy = devm_gpiod_get(dev, "mrdy", GPIOD_OUT_LOW); + if (IS_ERR(ifx_dev->gpio.mrdy)) { + dev_err(dev, "could not obtain mrdy GPIO\n"); + ret = PTR_ERR(ifx_dev->gpio.mrdy); + goto error_ret; + } + gpiod_set_consumer_name(ifx_dev->gpio.mrdy, "ifxModem mrdy"); + ifx_dev->gpio.srdy = devm_gpiod_get(dev, "srdy", GPIOD_IN); + if (IS_ERR(ifx_dev->gpio.srdy)) { + dev_err(dev, "could not obtain srdy GPIO\n"); + ret = PTR_ERR(ifx_dev->gpio.srdy); + goto error_ret; + } + gpiod_set_consumer_name(ifx_dev->gpio.srdy, "ifxModem srdy"); + ifx_dev->gpio.reset_out = devm_gpiod_get(dev, "rst_out", GPIOD_IN); + if (IS_ERR(ifx_dev->gpio.reset_out)) { + dev_err(dev, "could not obtain rst_out GPIO\n"); + ret = PTR_ERR(ifx_dev->gpio.reset_out); + goto error_ret; + } + gpiod_set_consumer_name(ifx_dev->gpio.reset_out, "ifxModem reset out"); + ifx_dev->gpio.pmu_reset = devm_gpiod_get(dev, "pmu_reset", GPIOD_ASIS); + if (IS_ERR(ifx_dev->gpio.pmu_reset)) { + dev_err(dev, "could not obtain pmu_reset GPIO\n"); + ret = PTR_ERR(ifx_dev->gpio.pmu_reset); + goto error_ret; + } + gpiod_set_consumer_name(ifx_dev->gpio.pmu_reset, "ifxModem PMU reset"); + + ret = request_irq(gpiod_to_irq(ifx_dev->gpio.reset_out), + ifx_spi_reset_interrupt, + IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME, + ifx_dev); + if (ret) { + dev_err(dev, "Unable to get irq %x\n", + gpiod_to_irq(ifx_dev->gpio.reset_out)); + goto error_ret; + } + + ret = ifx_spi_reset(ifx_dev); + + ret = request_irq(gpiod_to_irq(ifx_dev->gpio.srdy), + ifx_spi_srdy_interrupt, IRQF_TRIGGER_RISING, DRVNAME, + ifx_dev); + if (ret) { + dev_err(dev, "Unable to get irq %x", + gpiod_to_irq(ifx_dev->gpio.srdy)); + goto error_ret2; + } + + /* set pm runtime power state and register with power system */ + pm_runtime_set_active(dev); + pm_runtime_enable(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 = gpiod_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_ret2: + free_irq(gpiod_to_irq(ifx_dev->gpio.reset_out), ifx_dev); +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); + + pm_runtime_disable(&spi->dev); + + /* free irq */ + free_irq(gpiod_to_irq(ifx_dev->gpio.reset_out), ifx_dev); + free_irq(gpiod_to_irq(ifx_dev->gpio.srdy), ifx_dev); + + /* 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, + }, + .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 */ + spi_unregister_driver(&ifx_spi_driver); + tty_unregister_driver(tty_drv); + put_tty_driver(tty_drv); + 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(&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(&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"); |