diff options
Diffstat (limited to 'drivers/misc/ti-st/st_core.c')
| -rw-r--r-- | drivers/misc/ti-st/st_core.c | 929 |
1 files changed, 929 insertions, 0 deletions
diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c new file mode 100644 index 000000000..ca115f344 --- /dev/null +++ b/drivers/misc/ti-st/st_core.c @@ -0,0 +1,929 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Shared Transport Line discipline driver Core + * This hooks up ST KIM driver and ST LL driver + * Copyright (C) 2009-2010 Texas Instruments + * Author: Pavan Savoy <pavan_savoy@ti.com> + */ + +#define pr_fmt(fmt) "(stc): " fmt +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/tty.h> + +#include <linux/seq_file.h> +#include <linux/skbuff.h> + +#include <linux/ti_wilink_st.h> +#include <linux/netdevice.h> + +extern void st_kim_recv(void *, const unsigned char *, long); +void st_int_recv(void *, const unsigned char *, long); +/* + * function pointer pointing to either, + * st_kim_recv during registration to receive fw download responses + * st_int_recv after registration to receive proto stack responses + */ +static void (*st_recv) (void *, const unsigned char *, long); + +/********************************************************************/ +static void add_channel_to_table(struct st_data_s *st_gdata, + struct st_proto_s *new_proto) +{ + pr_info("%s: id %d\n", __func__, new_proto->chnl_id); + /* list now has the channel id as index itself */ + st_gdata->list[new_proto->chnl_id] = new_proto; + st_gdata->is_registered[new_proto->chnl_id] = true; +} + +static void remove_channel_from_table(struct st_data_s *st_gdata, + struct st_proto_s *proto) +{ + pr_info("%s: id %d\n", __func__, proto->chnl_id); +/* st_gdata->list[proto->chnl_id] = NULL; */ + st_gdata->is_registered[proto->chnl_id] = false; +} + +/* + * called from KIM during firmware download. + * + * This is a wrapper function to tty->ops->write_room. + * It returns number of free space available in + * uart tx buffer. + */ +int st_get_uart_wr_room(struct st_data_s *st_gdata) +{ + struct tty_struct *tty; + if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) { + pr_err("tty unavailable to perform write"); + return -1; + } + tty = st_gdata->tty; + return tty->ops->write_room(tty); +} + +/* + * can be called in from + * -- KIM (during fw download) + * -- ST Core (during st_write) + * + * This is the internal write function - a wrapper + * to tty->ops->write + */ +int st_int_write(struct st_data_s *st_gdata, + const unsigned char *data, int count) +{ + struct tty_struct *tty; + if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) { + pr_err("tty unavailable to perform write"); + return -EINVAL; + } + tty = st_gdata->tty; +#ifdef VERBOSE + print_hex_dump(KERN_DEBUG, "<out<", DUMP_PREFIX_NONE, + 16, 1, data, count, 0); +#endif + return tty->ops->write(tty, data, count); + +} + +/* + * push the skb received to relevant + * protocol stacks + */ +static void st_send_frame(unsigned char chnl_id, struct st_data_s *st_gdata) +{ + pr_debug(" %s(prot:%d) ", __func__, chnl_id); + + if (unlikely + (st_gdata == NULL || st_gdata->rx_skb == NULL + || st_gdata->is_registered[chnl_id] == false)) { + pr_err("chnl_id %d not registered, no data to send?", + chnl_id); + kfree_skb(st_gdata->rx_skb); + return; + } + /* + * this cannot fail + * this shouldn't take long + * - should be just skb_queue_tail for the + * protocol stack driver + */ + if (likely(st_gdata->list[chnl_id]->recv != NULL)) { + if (unlikely + (st_gdata->list[chnl_id]->recv + (st_gdata->list[chnl_id]->priv_data, st_gdata->rx_skb) + != 0)) { + pr_err(" proto stack %d's ->recv failed", chnl_id); + kfree_skb(st_gdata->rx_skb); + return; + } + } else { + pr_err(" proto stack %d's ->recv null", chnl_id); + kfree_skb(st_gdata->rx_skb); + } + return; +} + +/* + * st_reg_complete - to call registration complete callbacks + * of all protocol stack drivers + * This function is being called with spin lock held, protocol drivers are + * only expected to complete their waits and do nothing more than that. + */ +static void st_reg_complete(struct st_data_s *st_gdata, int err) +{ + unsigned char i = 0; + pr_info(" %s ", __func__); + for (i = 0; i < ST_MAX_CHANNELS; i++) { + if (likely(st_gdata != NULL && + st_gdata->is_registered[i] == true && + st_gdata->list[i]->reg_complete_cb != NULL)) { + st_gdata->list[i]->reg_complete_cb + (st_gdata->list[i]->priv_data, err); + pr_info("protocol %d's cb sent %d\n", i, err); + if (err) { /* cleanup registered protocol */ + st_gdata->is_registered[i] = false; + if (st_gdata->protos_registered) + st_gdata->protos_registered--; + } + } + } +} + +static inline int st_check_data_len(struct st_data_s *st_gdata, + unsigned char chnl_id, int len) +{ + int room = skb_tailroom(st_gdata->rx_skb); + + pr_debug("len %d room %d", len, room); + + if (!len) { + /* + * Received packet has only packet header and + * has zero length payload. So, ask ST CORE to + * forward the packet to protocol driver (BT/FM/GPS) + */ + st_send_frame(chnl_id, st_gdata); + + } else if (len > room) { + /* + * Received packet's payload length is larger. + * We can't accommodate it in created skb. + */ + pr_err("Data length is too large len %d room %d", len, + room); + kfree_skb(st_gdata->rx_skb); + } else { + /* + * Packet header has non-zero payload length and + * we have enough space in created skb. Lets read + * payload data */ + st_gdata->rx_state = ST_W4_DATA; + st_gdata->rx_count = len; + return len; + } + + /* Change ST state to continue to process next packet */ + st_gdata->rx_state = ST_W4_PACKET_TYPE; + st_gdata->rx_skb = NULL; + st_gdata->rx_count = 0; + st_gdata->rx_chnl = 0; + + return 0; +} + +/* + * st_wakeup_ack - internal function for action when wake-up ack + * received + */ +static inline void st_wakeup_ack(struct st_data_s *st_gdata, + unsigned char cmd) +{ + struct sk_buff *waiting_skb; + unsigned long flags = 0; + + spin_lock_irqsave(&st_gdata->lock, flags); + /* + * de-Q from waitQ and Q in txQ now that the + * chip is awake + */ + while ((waiting_skb = skb_dequeue(&st_gdata->tx_waitq))) + skb_queue_tail(&st_gdata->txq, waiting_skb); + + /* state forwarded to ST LL */ + st_ll_sleep_state(st_gdata, (unsigned long)cmd); + spin_unlock_irqrestore(&st_gdata->lock, flags); + + /* wake up to send the recently copied skbs from waitQ */ + st_tx_wakeup(st_gdata); +} + +/* + * st_int_recv - ST's internal receive function. + * Decodes received RAW data and forwards to corresponding + * client drivers (Bluetooth,FM,GPS..etc). + * This can receive various types of packets, + * HCI-Events, ACL, SCO, 4 types of HCI-LL PM packets + * CH-8 packets from FM, CH-9 packets from GPS cores. + */ +void st_int_recv(void *disc_data, + const unsigned char *data, long count) +{ + char *ptr; + struct st_proto_s *proto; + unsigned short payload_len = 0; + int len = 0; + unsigned char type = 0; + unsigned char *plen; + struct st_data_s *st_gdata = (struct st_data_s *)disc_data; + unsigned long flags; + + ptr = (char *)data; + /* tty_receive sent null ? */ + if (unlikely(ptr == NULL) || (st_gdata == NULL)) { + pr_err(" received null from TTY "); + return; + } + + pr_debug("count %ld rx_state %ld" + "rx_count %ld", count, st_gdata->rx_state, + st_gdata->rx_count); + + spin_lock_irqsave(&st_gdata->lock, flags); + /* Decode received bytes here */ + while (count) { + if (st_gdata->rx_count) { + len = min_t(unsigned int, st_gdata->rx_count, count); + skb_put_data(st_gdata->rx_skb, ptr, len); + st_gdata->rx_count -= len; + count -= len; + ptr += len; + + if (st_gdata->rx_count) + continue; + + /* Check ST RX state machine , where are we? */ + switch (st_gdata->rx_state) { + /* Waiting for complete packet ? */ + case ST_W4_DATA: + pr_debug("Complete pkt received"); + /* + * Ask ST CORE to forward + * the packet to protocol driver + */ + st_send_frame(st_gdata->rx_chnl, st_gdata); + + st_gdata->rx_state = ST_W4_PACKET_TYPE; + st_gdata->rx_skb = NULL; + continue; + /* parse the header to know details */ + case ST_W4_HEADER: + proto = st_gdata->list[st_gdata->rx_chnl]; + plen = + &st_gdata->rx_skb->data + [proto->offset_len_in_hdr]; + pr_debug("plen pointing to %x\n", *plen); + if (proto->len_size == 1) /* 1 byte len field */ + payload_len = *(unsigned char *)plen; + else if (proto->len_size == 2) + payload_len = + __le16_to_cpu(*(unsigned short *)plen); + else + pr_info("%s: invalid length " + "for id %d\n", + __func__, proto->chnl_id); + st_check_data_len(st_gdata, proto->chnl_id, + payload_len); + pr_debug("off %d, pay len %d\n", + proto->offset_len_in_hdr, payload_len); + continue; + } /* end of switch rx_state */ + } + + /* end of if rx_count */ + + /* + * Check first byte of packet and identify module + * owner (BT/FM/GPS) + */ + switch (*ptr) { + case LL_SLEEP_IND: + case LL_SLEEP_ACK: + case LL_WAKE_UP_IND: + pr_debug("PM packet"); + /* + * this takes appropriate action based on + * sleep state received -- + */ + st_ll_sleep_state(st_gdata, *ptr); + /* + * if WAKEUP_IND collides copy from waitq to txq + * and assume chip awake + */ + spin_unlock_irqrestore(&st_gdata->lock, flags); + if (st_ll_getstate(st_gdata) == ST_LL_AWAKE) + st_wakeup_ack(st_gdata, LL_WAKE_UP_ACK); + spin_lock_irqsave(&st_gdata->lock, flags); + + ptr++; + count--; + continue; + case LL_WAKE_UP_ACK: + pr_debug("PM packet"); + + spin_unlock_irqrestore(&st_gdata->lock, flags); + /* wake up ack received */ + st_wakeup_ack(st_gdata, *ptr); + spin_lock_irqsave(&st_gdata->lock, flags); + + ptr++; + count--; + continue; + /* Unknow packet? */ + default: + type = *ptr; + + /* + * Default case means non-HCILL packets, + * possibilities are packets for: + * (a) valid protocol - Supported Protocols within + * the ST_MAX_CHANNELS. + * (b) registered protocol - Checked by + * "st_gdata->list[type] == NULL)" are supported + * protocols only. + * Rules out any invalid protocol and + * unregistered protocols with channel ID < 16. + */ + + if ((type >= ST_MAX_CHANNELS) || + (st_gdata->list[type] == NULL)) { + pr_err("chip/interface misbehavior: " + "dropping frame starting " + "with 0x%02x\n", type); + goto done; + } + + st_gdata->rx_skb = alloc_skb( + st_gdata->list[type]->max_frame_size, + GFP_ATOMIC); + if (st_gdata->rx_skb == NULL) { + pr_err("out of memory: dropping\n"); + goto done; + } + + skb_reserve(st_gdata->rx_skb, + st_gdata->list[type]->reserve); + /* next 2 required for BT only */ + st_gdata->rx_skb->cb[0] = type; /*pkt_type*/ + st_gdata->rx_skb->cb[1] = 0; /*incoming*/ + st_gdata->rx_chnl = *ptr; + st_gdata->rx_state = ST_W4_HEADER; + st_gdata->rx_count = st_gdata->list[type]->hdr_len; + pr_debug("rx_count %ld\n", st_gdata->rx_count); + }; + ptr++; + count--; + } +done: + spin_unlock_irqrestore(&st_gdata->lock, flags); + pr_debug("done %s", __func__); + return; +} + +/* + * st_int_dequeue - internal de-Q function. + * If the previous data set was not written + * completely, return that skb which has the pending data. + * In normal cases, return top of txq. + */ +static struct sk_buff *st_int_dequeue(struct st_data_s *st_gdata) +{ + struct sk_buff *returning_skb; + + pr_debug("%s", __func__); + if (st_gdata->tx_skb != NULL) { + returning_skb = st_gdata->tx_skb; + st_gdata->tx_skb = NULL; + return returning_skb; + } + return skb_dequeue(&st_gdata->txq); +} + +/* + * st_int_enqueue - internal Q-ing function. + * Will either Q the skb to txq or the tx_waitq + * depending on the ST LL state. + * If the chip is asleep, then Q it onto waitq and + * wakeup the chip. + * txq and waitq needs protection since the other contexts + * may be sending data, waking up chip. + */ +static void st_int_enqueue(struct st_data_s *st_gdata, struct sk_buff *skb) +{ + unsigned long flags = 0; + + pr_debug("%s", __func__); + spin_lock_irqsave(&st_gdata->lock, flags); + + switch (st_ll_getstate(st_gdata)) { + case ST_LL_AWAKE: + pr_debug("ST LL is AWAKE, sending normally"); + skb_queue_tail(&st_gdata->txq, skb); + break; + case ST_LL_ASLEEP_TO_AWAKE: + skb_queue_tail(&st_gdata->tx_waitq, skb); + break; + case ST_LL_AWAKE_TO_ASLEEP: + pr_err("ST LL is illegal state(%ld)," + "purging received skb.", st_ll_getstate(st_gdata)); + dev_kfree_skb_irq(skb); + break; + case ST_LL_ASLEEP: + skb_queue_tail(&st_gdata->tx_waitq, skb); + st_ll_wakeup(st_gdata); + break; + default: + pr_err("ST LL is illegal state(%ld)," + "purging received skb.", st_ll_getstate(st_gdata)); + dev_kfree_skb_irq(skb); + break; + } + + spin_unlock_irqrestore(&st_gdata->lock, flags); + pr_debug("done %s", __func__); + return; +} + +/* + * internal wakeup function + * called from either + * - TTY layer when write's finished + * - st_write (in context of the protocol stack) + */ +static void work_fn_write_wakeup(struct work_struct *work) +{ + struct st_data_s *st_gdata = container_of(work, struct st_data_s, + work_write_wakeup); + + st_tx_wakeup((void *)st_gdata); +} +void st_tx_wakeup(struct st_data_s *st_data) +{ + struct sk_buff *skb; + unsigned long flags; /* for irq save flags */ + pr_debug("%s", __func__); + /* check for sending & set flag sending here */ + if (test_and_set_bit(ST_TX_SENDING, &st_data->tx_state)) { + pr_debug("ST already sending"); + /* keep sending */ + set_bit(ST_TX_WAKEUP, &st_data->tx_state); + return; + /* TX_WAKEUP will be checked in another + * context + */ + } + do { /* come back if st_tx_wakeup is set */ + /* woke-up to write */ + clear_bit(ST_TX_WAKEUP, &st_data->tx_state); + while ((skb = st_int_dequeue(st_data))) { + int len; + spin_lock_irqsave(&st_data->lock, flags); + /* enable wake-up from TTY */ + set_bit(TTY_DO_WRITE_WAKEUP, &st_data->tty->flags); + len = st_int_write(st_data, skb->data, skb->len); + skb_pull(skb, len); + /* if skb->len = len as expected, skb->len=0 */ + if (skb->len) { + /* would be the next skb to be sent */ + st_data->tx_skb = skb; + spin_unlock_irqrestore(&st_data->lock, flags); + break; + } + dev_kfree_skb_irq(skb); + spin_unlock_irqrestore(&st_data->lock, flags); + } + /* if wake-up is set in another context- restart sending */ + } while (test_bit(ST_TX_WAKEUP, &st_data->tx_state)); + + /* clear flag sending */ + clear_bit(ST_TX_SENDING, &st_data->tx_state); +} + +/********************************************************************/ +/* functions called from ST KIM +*/ +void kim_st_list_protocols(struct st_data_s *st_gdata, void *buf) +{ + seq_printf(buf, "[%d]\nBT=%c\nFM=%c\nGPS=%c\n", + st_gdata->protos_registered, + st_gdata->is_registered[0x04] == true ? 'R' : 'U', + st_gdata->is_registered[0x08] == true ? 'R' : 'U', + st_gdata->is_registered[0x09] == true ? 'R' : 'U'); +} + +/********************************************************************/ +/* + * functions called from protocol stack drivers + * to be EXPORT-ed + */ +long st_register(struct st_proto_s *new_proto) +{ + struct st_data_s *st_gdata; + long err = 0; + unsigned long flags = 0; + + st_kim_ref(&st_gdata, 0); + if (st_gdata == NULL || new_proto == NULL || new_proto->recv == NULL + || new_proto->reg_complete_cb == NULL) { + pr_err("gdata/new_proto/recv or reg_complete_cb not ready"); + return -EINVAL; + } + + if (new_proto->chnl_id >= ST_MAX_CHANNELS) { + pr_err("chnl_id %d not supported", new_proto->chnl_id); + return -EPROTONOSUPPORT; + } + + if (st_gdata->is_registered[new_proto->chnl_id] == true) { + pr_err("chnl_id %d already registered", new_proto->chnl_id); + return -EALREADY; + } + + /* can be from process context only */ + spin_lock_irqsave(&st_gdata->lock, flags); + + if (test_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state)) { + pr_info(" ST_REG_IN_PROGRESS:%d ", new_proto->chnl_id); + /* fw download in progress */ + + add_channel_to_table(st_gdata, new_proto); + st_gdata->protos_registered++; + new_proto->write = st_write; + + set_bit(ST_REG_PENDING, &st_gdata->st_state); + spin_unlock_irqrestore(&st_gdata->lock, flags); + return -EINPROGRESS; + } else if (st_gdata->protos_registered == ST_EMPTY) { + pr_info(" chnl_id list empty :%d ", new_proto->chnl_id); + set_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state); + st_recv = st_kim_recv; + + /* enable the ST LL - to set default chip state */ + st_ll_enable(st_gdata); + + /* release lock previously held - re-locked below */ + spin_unlock_irqrestore(&st_gdata->lock, flags); + + /* + * this may take a while to complete + * since it involves BT fw download + */ + err = st_kim_start(st_gdata->kim_data); + if (err != 0) { + clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state); + if ((st_gdata->protos_registered != ST_EMPTY) && + (test_bit(ST_REG_PENDING, &st_gdata->st_state))) { + pr_err(" KIM failure complete callback "); + spin_lock_irqsave(&st_gdata->lock, flags); + st_reg_complete(st_gdata, err); + spin_unlock_irqrestore(&st_gdata->lock, flags); + clear_bit(ST_REG_PENDING, &st_gdata->st_state); + } + return -EINVAL; + } + + spin_lock_irqsave(&st_gdata->lock, flags); + + clear_bit(ST_REG_IN_PROGRESS, &st_gdata->st_state); + st_recv = st_int_recv; + + /* + * this is where all pending registration + * are signalled to be complete by calling callback functions + */ + if ((st_gdata->protos_registered != ST_EMPTY) && + (test_bit(ST_REG_PENDING, &st_gdata->st_state))) { + pr_debug(" call reg complete callback "); + st_reg_complete(st_gdata, 0); + } + clear_bit(ST_REG_PENDING, &st_gdata->st_state); + + /* + * check for already registered once more, + * since the above check is old + */ + if (st_gdata->is_registered[new_proto->chnl_id] == true) { + pr_err(" proto %d already registered ", + new_proto->chnl_id); + spin_unlock_irqrestore(&st_gdata->lock, flags); + return -EALREADY; + } + + add_channel_to_table(st_gdata, new_proto); + st_gdata->protos_registered++; + new_proto->write = st_write; + spin_unlock_irqrestore(&st_gdata->lock, flags); + return err; + } + /* if fw is already downloaded & new stack registers protocol */ + else { + add_channel_to_table(st_gdata, new_proto); + st_gdata->protos_registered++; + new_proto->write = st_write; + + /* lock already held before entering else */ + spin_unlock_irqrestore(&st_gdata->lock, flags); + return err; + } +} +EXPORT_SYMBOL_GPL(st_register); + +/* + * to unregister a protocol - + * to be called from protocol stack driver + */ +long st_unregister(struct st_proto_s *proto) +{ + long err = 0; + unsigned long flags = 0; + struct st_data_s *st_gdata; + + pr_debug("%s: %d ", __func__, proto->chnl_id); + + st_kim_ref(&st_gdata, 0); + if (!st_gdata || proto->chnl_id >= ST_MAX_CHANNELS) { + pr_err(" chnl_id %d not supported", proto->chnl_id); + return -EPROTONOSUPPORT; + } + + spin_lock_irqsave(&st_gdata->lock, flags); + + if (st_gdata->is_registered[proto->chnl_id] == false) { + pr_err(" chnl_id %d not registered", proto->chnl_id); + spin_unlock_irqrestore(&st_gdata->lock, flags); + return -EPROTONOSUPPORT; + } + + if (st_gdata->protos_registered) + st_gdata->protos_registered--; + + remove_channel_from_table(st_gdata, proto); + spin_unlock_irqrestore(&st_gdata->lock, flags); + + if ((st_gdata->protos_registered == ST_EMPTY) && + (!test_bit(ST_REG_PENDING, &st_gdata->st_state))) { + pr_info(" all chnl_ids unregistered "); + + /* stop traffic on tty */ + if (st_gdata->tty) { + tty_ldisc_flush(st_gdata->tty); + stop_tty(st_gdata->tty); + } + + /* all chnl_ids now unregistered */ + st_kim_stop(st_gdata->kim_data); + /* disable ST LL */ + st_ll_disable(st_gdata); + } + return err; +} + +/* + * called in protocol stack drivers + * via the write function pointer + */ +long st_write(struct sk_buff *skb) +{ + struct st_data_s *st_gdata; + long len; + + st_kim_ref(&st_gdata, 0); + if (unlikely(skb == NULL || st_gdata == NULL + || st_gdata->tty == NULL)) { + pr_err("data/tty unavailable to perform write"); + return -EINVAL; + } + + pr_debug("%d to be written", skb->len); + len = skb->len; + + /* st_ll to decide where to enqueue the skb */ + st_int_enqueue(st_gdata, skb); + /* wake up */ + st_tx_wakeup(st_gdata); + + /* return number of bytes written */ + return len; +} + +/* for protocols making use of shared transport */ +EXPORT_SYMBOL_GPL(st_unregister); + +/********************************************************************/ +/* + * functions called from TTY layer + */ +static int st_tty_open(struct tty_struct *tty) +{ + struct st_data_s *st_gdata; + pr_info("%s ", __func__); + + st_kim_ref(&st_gdata, 0); + st_gdata->tty = tty; + tty->disc_data = st_gdata; + + /* don't do an wakeup for now */ + clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + + /* mem already allocated + */ + tty->receive_room = 65536; + /* Flush any pending characters in the driver and discipline. */ + tty_ldisc_flush(tty); + tty_driver_flush_buffer(tty); + /* + * signal to UIM via KIM that - + * installation of N_TI_WL ldisc is complete + */ + st_kim_complete(st_gdata->kim_data); + pr_debug("done %s", __func__); + + return 0; +} + +static void st_tty_close(struct tty_struct *tty) +{ + unsigned char i; + unsigned long flags; + struct st_data_s *st_gdata = tty->disc_data; + + pr_info("%s ", __func__); + + /* + * TODO: + * if a protocol has been registered & line discipline + * un-installed for some reason - what should be done ? + */ + spin_lock_irqsave(&st_gdata->lock, flags); + for (i = ST_BT; i < ST_MAX_CHANNELS; i++) { + if (st_gdata->is_registered[i] == true) + pr_err("%d not un-registered", i); + st_gdata->list[i] = NULL; + st_gdata->is_registered[i] = false; + } + st_gdata->protos_registered = 0; + spin_unlock_irqrestore(&st_gdata->lock, flags); + /* + * signal to UIM via KIM that - + * N_TI_WL ldisc is un-installed + */ + st_kim_complete(st_gdata->kim_data); + st_gdata->tty = NULL; + /* Flush any pending characters in the driver and discipline. */ + tty_ldisc_flush(tty); + tty_driver_flush_buffer(tty); + + spin_lock_irqsave(&st_gdata->lock, flags); + /* empty out txq and tx_waitq */ + skb_queue_purge(&st_gdata->txq); + skb_queue_purge(&st_gdata->tx_waitq); + /* reset the TTY Rx states of ST */ + st_gdata->rx_count = 0; + st_gdata->rx_state = ST_W4_PACKET_TYPE; + kfree_skb(st_gdata->rx_skb); + st_gdata->rx_skb = NULL; + spin_unlock_irqrestore(&st_gdata->lock, flags); + + pr_debug("%s: done ", __func__); +} + +static void st_tty_receive(struct tty_struct *tty, const unsigned char *data, + char *tty_flags, int count) +{ +#ifdef VERBOSE + print_hex_dump(KERN_DEBUG, ">in>", DUMP_PREFIX_NONE, + 16, 1, data, count, 0); +#endif + + /* + * if fw download is in progress then route incoming data + * to KIM for validation + */ + st_recv(tty->disc_data, data, count); + pr_debug("done %s", __func__); +} + +/* + * wake-up function called in from the TTY layer + * inside the internal wakeup function will be called + */ +static void st_tty_wakeup(struct tty_struct *tty) +{ + struct st_data_s *st_gdata = tty->disc_data; + pr_debug("%s ", __func__); + /* don't do an wakeup for now */ + clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + + /* + * schedule the internal wakeup instead of calling directly to + * avoid lockup (port->lock needed in tty->ops->write is + * already taken here + */ + schedule_work(&st_gdata->work_write_wakeup); +} + +static void st_tty_flush_buffer(struct tty_struct *tty) +{ + struct st_data_s *st_gdata = tty->disc_data; + pr_debug("%s ", __func__); + + kfree_skb(st_gdata->tx_skb); + st_gdata->tx_skb = NULL; + + tty_driver_flush_buffer(tty); + return; +} + +static struct tty_ldisc_ops st_ldisc_ops = { + .magic = TTY_LDISC_MAGIC, + .name = "n_st", + .open = st_tty_open, + .close = st_tty_close, + .receive_buf = st_tty_receive, + .write_wakeup = st_tty_wakeup, + .flush_buffer = st_tty_flush_buffer, + .owner = THIS_MODULE +}; + +/********************************************************************/ +int st_core_init(struct st_data_s **core_data) +{ + struct st_data_s *st_gdata; + long err; + + err = tty_register_ldisc(N_TI_WL, &st_ldisc_ops); + if (err) { + pr_err("error registering %d line discipline %ld", + N_TI_WL, err); + return err; + } + pr_debug("registered n_shared line discipline"); + + st_gdata = kzalloc(sizeof(struct st_data_s), GFP_KERNEL); + if (!st_gdata) { + pr_err("memory allocation failed"); + err = tty_unregister_ldisc(N_TI_WL); + if (err) + pr_err("unable to un-register ldisc %ld", err); + err = -ENOMEM; + return err; + } + + /* Initialize ST TxQ and Tx waitQ queue head. All BT/FM/GPS module skb's + * will be pushed in this queue for actual transmission. + */ + skb_queue_head_init(&st_gdata->txq); + skb_queue_head_init(&st_gdata->tx_waitq); + + /* Locking used in st_int_enqueue() to avoid multiple execution */ + spin_lock_init(&st_gdata->lock); + + err = st_ll_init(st_gdata); + if (err) { + pr_err("error during st_ll initialization(%ld)", err); + kfree(st_gdata); + err = tty_unregister_ldisc(N_TI_WL); + if (err) + pr_err("unable to un-register ldisc"); + return err; + } + + INIT_WORK(&st_gdata->work_write_wakeup, work_fn_write_wakeup); + + *core_data = st_gdata; + return 0; +} + +void st_core_exit(struct st_data_s *st_gdata) +{ + long err; + /* internal module cleanup */ + err = st_ll_deinit(st_gdata); + if (err) + pr_err("error during deinit of ST LL %ld", err); + + if (st_gdata != NULL) { + /* Free ST Tx Qs and skbs */ + skb_queue_purge(&st_gdata->txq); + skb_queue_purge(&st_gdata->tx_waitq); + kfree_skb(st_gdata->rx_skb); + kfree_skb(st_gdata->tx_skb); + /* TTY ldisc cleanup */ + err = tty_unregister_ldisc(N_TI_WL); + if (err) + pr_err("unable to un-register ldisc %ld", err); + /* free the global data pointer */ + kfree(st_gdata); + } +} |