/* * Copyright (C) ST-Ericsson AB 2010 * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com * Author: Daniel Martensson / daniel.martensson@stericsson.com * Dmitry.Tarnyagin / dmitry.tarnyagin@stericsson.com * License terms: GNU General Public License (GPL) version 2. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE_LICENSE("GPL"); MODULE_AUTHOR("Daniel Martensson"); MODULE_DESCRIPTION("CAIF HSI driver"); /* Returns the number of padding bytes for alignment. */ #define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\ (((pow)-((x)&((pow)-1))))) /* * HSI padding options. * Warning: must be a base of 2 (& operation used) and can not be zero ! */ static int hsi_head_align = 4; module_param(hsi_head_align, int, S_IRUGO); MODULE_PARM_DESC(hsi_head_align, "HSI head alignment."); static int hsi_tail_align = 4; module_param(hsi_tail_align, int, S_IRUGO); MODULE_PARM_DESC(hsi_tail_align, "HSI tail alignment."); /* * HSI link layer flowcontrol thresholds. * Warning: A high threshold value migth increase throughput but it will at * the same time prevent channel prioritization and increase the risk of * flooding the modem. The high threshold should be above the low. */ static int hsi_high_threshold = 100; module_param(hsi_high_threshold, int, S_IRUGO); MODULE_PARM_DESC(hsi_high_threshold, "HSI high threshold (FLOW OFF)."); static int hsi_low_threshold = 50; module_param(hsi_low_threshold, int, S_IRUGO); MODULE_PARM_DESC(hsi_low_threshold, "HSI high threshold (FLOW ON)."); #define ON 1 #define OFF 0 /* * Threshold values for the HSI packet queue. Flowcontrol will be asserted * when the number of packets exceeds HIGH_WATER_MARK. It will not be * de-asserted before the number of packets drops below LOW_WATER_MARK. */ #define LOW_WATER_MARK hsi_low_threshold #define HIGH_WATER_MARK hsi_high_threshold static LIST_HEAD(cfhsi_list); static spinlock_t cfhsi_list_lock; static void cfhsi_inactivity_tout(unsigned long arg) { struct cfhsi *cfhsi = (struct cfhsi *)arg; dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); /* Schedule power down work queue. */ if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) queue_work(cfhsi->wq, &cfhsi->wake_down_work); } static void cfhsi_abort_tx(struct cfhsi *cfhsi) { struct sk_buff *skb; for (;;) { spin_lock_bh(&cfhsi->lock); skb = skb_dequeue(&cfhsi->qhead); if (!skb) break; cfhsi->ndev->stats.tx_errors++; cfhsi->ndev->stats.tx_dropped++; spin_unlock_bh(&cfhsi->lock); kfree_skb(skb); } cfhsi->tx_state = CFHSI_TX_STATE_IDLE; if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) mod_timer(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT); spin_unlock_bh(&cfhsi->lock); } static int cfhsi_flush_fifo(struct cfhsi *cfhsi) { char buffer[32]; /* Any reasonable value */ size_t fifo_occupancy; int ret; dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); ret = cfhsi->dev->cfhsi_wake_up(cfhsi->dev); if (ret) { dev_warn(&cfhsi->ndev->dev, "%s: can't wake up HSI interface: %d.\n", __func__, ret); return ret; } do { ret = cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev, &fifo_occupancy); if (ret) { dev_warn(&cfhsi->ndev->dev, "%s: can't get FIFO occupancy: %d.\n", __func__, ret); break; } else if (!fifo_occupancy) /* No more data, exitting normally */ break; fifo_occupancy = min(sizeof(buffer), fifo_occupancy); set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits); ret = cfhsi->dev->cfhsi_rx(buffer, fifo_occupancy, cfhsi->dev); if (ret) { clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits); dev_warn(&cfhsi->ndev->dev, "%s: can't read data: %d.\n", __func__, ret); break; } ret = 5 * HZ; wait_event_interruptible_timeout(cfhsi->flush_fifo_wait, !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret); if (ret < 0) { dev_warn(&cfhsi->ndev->dev, "%s: can't wait for flush complete: %d.\n", __func__, ret); break; } else if (!ret) { ret = -ETIMEDOUT; dev_warn(&cfhsi->ndev->dev, "%s: timeout waiting for flush complete.\n", __func__); break; } } while (1); cfhsi->dev->cfhsi_wake_down(cfhsi->dev); return ret; } static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi) { int nfrms = 0; int pld_len = 0; struct sk_buff *skb; u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ; skb = skb_dequeue(&cfhsi->qhead); if (!skb) return 0; /* Check if we can embed a CAIF frame. */ if (skb->len < CFHSI_MAX_EMB_FRM_SZ) { struct caif_payload_info *info; int hpad = 0; int tpad = 0; /* Calculate needed head alignment and tail alignment. */ info = (struct caif_payload_info *)&skb->cb; hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align); tpad = PAD_POW2((skb->len + hpad), hsi_tail_align); /* Check if frame still fits with added alignment. */ if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) { u8 *pemb = desc->emb_frm; desc->offset = CFHSI_DESC_SHORT_SZ; *pemb = (u8)(hpad - 1); pemb += hpad; /* Update network statistics. */ cfhsi->ndev->stats.tx_packets++; cfhsi->ndev->stats.tx_bytes += skb->len; /* Copy in embedded CAIF frame. */ skb_copy_bits(skb, 0, pemb, skb->len); consume_skb(skb); skb = NULL; } } else /* Clear offset. */ desc->offset = 0; /* Create payload CAIF frames. */ pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ; while (nfrms < CFHSI_MAX_PKTS) { struct caif_payload_info *info; int hpad = 0; int tpad = 0; if (!skb) skb = skb_dequeue(&cfhsi->qhead); if (!skb) break; /* Calculate needed head alignment and tail alignment. */ info = (struct caif_payload_info *)&skb->cb; hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align); tpad = PAD_POW2((skb->len + hpad), hsi_tail_align); /* Fill in CAIF frame length in descriptor. */ desc->cffrm_len[nfrms] = hpad + skb->len + tpad; /* Fill head padding information. */ *pfrm = (u8)(hpad - 1); pfrm += hpad; /* Update network statistics. */ cfhsi->ndev->stats.tx_packets++; cfhsi->ndev->stats.tx_bytes += skb->len; /* Copy in CAIF frame. */ skb_copy_bits(skb, 0, pfrm, skb->len); /* Update payload length. */ pld_len += desc->cffrm_len[nfrms]; /* Update frame pointer. */ pfrm += skb->len + tpad; consume_skb(skb); skb = NULL; /* Update number of frames. */ nfrms++; } /* Unused length fields should be zero-filled (according to SPEC). */ while (nfrms < CFHSI_MAX_PKTS) { desc->cffrm_len[nfrms] = 0x0000; nfrms++; } /* Check if we can piggy-back another descriptor. */ skb = skb_peek(&cfhsi->qhead); if (skb) desc->header |= CFHSI_PIGGY_DESC; else desc->header &= ~CFHSI_PIGGY_DESC; return CFHSI_DESC_SZ + pld_len; } static void cfhsi_tx_done_work(struct work_struct *work) { struct cfhsi *cfhsi = NULL; struct cfhsi_desc *desc = NULL; int len = 0; int res; cfhsi = container_of(work, struct cfhsi, tx_done_work); dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) return; desc = (struct cfhsi_desc *)cfhsi->tx_buf; do { /* * Send flow on if flow off has been previously signalled * and number of packets is below low water mark. */ spin_lock_bh(&cfhsi->lock); if (cfhsi->flow_off_sent && cfhsi->qhead.qlen <= cfhsi->q_low_mark && cfhsi->cfdev.flowctrl) { cfhsi->flow_off_sent = 0; cfhsi->cfdev.flowctrl(cfhsi->ndev, ON); } spin_unlock_bh(&cfhsi->lock); /* Create HSI frame. */ len = cfhsi_tx_frm(desc, cfhsi); if (!len) { cfhsi->tx_state = CFHSI_TX_STATE_IDLE; /* Start inactivity timer. */ mod_timer(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT); break; } /* Set up new transfer. */ res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev); if (WARN_ON(res < 0)) { dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n", __func__, res); } } while (res < 0); } static void cfhsi_tx_done_cb(struct cfhsi_drv *drv) { struct cfhsi *cfhsi; cfhsi = container_of(drv, struct cfhsi, drv); dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) return; queue_work(cfhsi->wq, &cfhsi->tx_done_work); } static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi) { int xfer_sz = 0; int nfrms = 0; u16 *plen = NULL; u8 *pfrm = NULL; if ((desc->header & ~CFHSI_PIGGY_DESC) || (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) { dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n", __func__); return 0; } /* Check for embedded CAIF frame. */ if (desc->offset) { struct sk_buff *skb; u8 *dst = NULL; int len = 0, retries = 0; pfrm = ((u8 *)desc) + desc->offset; /* Remove offset padding. */ pfrm += *pfrm + 1; /* Read length of CAIF frame (little endian). */ len = *pfrm; len |= ((*(pfrm+1)) << 8) & 0xFF00; len += 2; /* Add FCS fields. */ /* Allocate SKB (OK even in IRQ context). */ skb = alloc_skb(len + 1, GFP_KERNEL); while (!skb) { retries++; schedule_timeout(1); skb = alloc_skb(len + 1, GFP_KERNEL); if (skb) { printk(KERN_WARNING "%s: slept for %u " "before getting memory\n", __func__, retries); break; } if (retries > HZ) { printk(KERN_ERR "%s: slept for 1HZ and " "did not get memory\n", __func__); cfhsi->ndev->stats.rx_dropped++; goto drop_frame; } } caif_assert(skb != NULL); dst = skb_put(skb, len); memcpy(dst, pfrm, len); skb->protocol = htons(ETH_P_CAIF); skb_reset_mac_header(skb); skb->dev = cfhsi->ndev; /* * We are called from a arch specific platform device. * Unfortunately we don't know what context we're * running in. */ if (in_interrupt()) netif_rx(skb); else netif_rx_ni(skb); /* Update network statistics. */ cfhsi->ndev->stats.rx_packets++; cfhsi->ndev->stats.rx_bytes += len; } drop_frame: /* Calculate transfer length. */ plen = desc->cffrm_len; while (nfrms < CFHSI_MAX_PKTS && *plen) { xfer_sz += *plen; plen++; nfrms++; } /* Check for piggy-backed descriptor. */ if (desc->header & CFHSI_PIGGY_DESC) xfer_sz += CFHSI_DESC_SZ; if (xfer_sz % 4) { dev_err(&cfhsi->ndev->dev, "%s: Invalid payload len: %d, ignored.\n", __func__, xfer_sz); xfer_sz = 0; } return xfer_sz; } static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi) { int rx_sz = 0; int nfrms = 0; u16 *plen = NULL; u8 *pfrm = NULL; /* Sanity check header and offset. */ if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) || (desc->offset > CFHSI_MAX_EMB_FRM_SZ))) { dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n", __func__); return -EINVAL; } /* Set frame pointer to start of payload. */ pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ; plen = desc->cffrm_len; while (nfrms < CFHSI_MAX_PKTS && *plen) { struct sk_buff *skb; u8 *dst = NULL; u8 *pcffrm = NULL; int len = 0, retries = 0; if (WARN_ON(desc->cffrm_len[nfrms] > CFHSI_MAX_PAYLOAD_SZ)) { dev_err(&cfhsi->ndev->dev, "%s: Invalid payload.\n", __func__); return -EINVAL; } /* CAIF frame starts after head padding. */ pcffrm = pfrm + *pfrm + 1; /* Read length of CAIF frame (little endian). */ len = *pcffrm; len |= ((*(pcffrm + 1)) << 8) & 0xFF00; len += 2; /* Add FCS fields. */ /* Allocate SKB (OK even in IRQ context). */ skb = alloc_skb(len + 1, GFP_KERNEL); while (!skb) { retries++; schedule_timeout(1); skb = alloc_skb(len + 1, GFP_KERNEL); if (skb) { printk(KERN_WARNING "%s: slept for %u " "before getting memory\n", __func__, retries); break; } if (retries > HZ) { printk(KERN_ERR "%s: slept for 1HZ " "and did not get memory\n", __func__); cfhsi->ndev->stats.rx_dropped++; goto drop_frame; } } caif_assert(skb != NULL); dst = skb_put(skb, len); memcpy(dst, pcffrm, len); skb->protocol = htons(ETH_P_CAIF); skb_reset_mac_header(skb); skb->dev = cfhsi->ndev; /* * We're called from a platform device, * and don't know the context we're running in. */ if (in_interrupt()) netif_rx(skb); else netif_rx_ni(skb); /* Update network statistics. */ cfhsi->ndev->stats.rx_packets++; cfhsi->ndev->stats.rx_bytes += len; drop_frame: pfrm += *plen; rx_sz += *plen; plen++; nfrms++; } return rx_sz; } static void cfhsi_rx_done_work(struct work_struct *work) { int res; int desc_pld_len = 0; struct cfhsi *cfhsi = NULL; struct cfhsi_desc *desc = NULL; cfhsi = container_of(work, struct cfhsi, rx_done_work); desc = (struct cfhsi_desc *)cfhsi->rx_buf; dev_dbg(&cfhsi->ndev->dev, "%s: Kick timer if pending.\n", __func__); if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) return; /* Update inactivity timer if pending. */ mod_timer_pending(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT); if (cfhsi->rx_state == CFHSI_RX_STATE_DESC) { desc_pld_len = cfhsi_rx_desc(desc, cfhsi); } else { int pld_len; pld_len = cfhsi_rx_pld(desc, cfhsi); if ((pld_len > 0) && (desc->header & CFHSI_PIGGY_DESC)) { struct cfhsi_desc *piggy_desc; piggy_desc = (struct cfhsi_desc *) (desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ + pld_len); /* Extract piggy-backed descriptor. */ desc_pld_len = cfhsi_rx_desc(piggy_desc, cfhsi); /* * Copy needed information from the piggy-backed * descriptor to the descriptor in the start. */ memcpy((u8 *)desc, (u8 *)piggy_desc, CFHSI_DESC_SHORT_SZ); } } if (desc_pld_len) { cfhsi->rx_state = CFHSI_RX_STATE_PAYLOAD; cfhsi->rx_ptr = cfhsi->rx_buf + CFHSI_DESC_SZ; cfhsi->rx_len = desc_pld_len; } else { cfhsi->rx_state = CFHSI_RX_STATE_DESC; cfhsi->rx_ptr = cfhsi->rx_buf; cfhsi->rx_len = CFHSI_DESC_SZ; } clear_bit(CFHSI_PENDING_RX, &cfhsi->bits); if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) { /* Set up new transfer. */ dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n", __func__); res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->dev); if (WARN_ON(res < 0)) { dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n", __func__, res); cfhsi->ndev->stats.rx_errors++; cfhsi->ndev->stats.rx_dropped++; } } } static void cfhsi_rx_done_cb(struct cfhsi_drv *drv) { struct cfhsi *cfhsi; cfhsi = container_of(drv, struct cfhsi, drv); dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) return; set_bit(CFHSI_PENDING_RX, &cfhsi->bits); if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits)) wake_up_interruptible(&cfhsi->flush_fifo_wait); else queue_work(cfhsi->wq, &cfhsi->rx_done_work); } static void cfhsi_wake_up(struct work_struct *work) { struct cfhsi *cfhsi = NULL; int res; int len; long ret; cfhsi = container_of(work, struct cfhsi, wake_up_work); if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) return; if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) { /* It happenes when wakeup is requested by * both ends at the same time. */ clear_bit(CFHSI_WAKE_UP, &cfhsi->bits); return; } /* Activate wake line. */ cfhsi->dev->cfhsi_wake_up(cfhsi->dev); dev_dbg(&cfhsi->ndev->dev, "%s: Start waiting.\n", __func__); /* Wait for acknowledge. */ ret = CFHSI_WAKEUP_TOUT; wait_event_interruptible_timeout(cfhsi->wake_up_wait, test_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits), ret); if (unlikely(ret < 0)) { /* Interrupted by signal. */ dev_info(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n", __func__, ret); clear_bit(CFHSI_WAKE_UP, &cfhsi->bits); cfhsi->dev->cfhsi_wake_down(cfhsi->dev); return; } else if (!ret) { /* Wakeup timeout */ dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n", __func__); clear_bit(CFHSI_WAKE_UP, &cfhsi->bits); cfhsi->dev->cfhsi_wake_down(cfhsi->dev); return; } dev_dbg(&cfhsi->ndev->dev, "%s: Woken.\n", __func__); /* Clear power up bit. */ set_bit(CFHSI_AWAKE, &cfhsi->bits); clear_bit(CFHSI_WAKE_UP, &cfhsi->bits); /* Resume read operation. */ if (!test_bit(CFHSI_PENDING_RX, &cfhsi->bits)) { dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n", __func__); res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->dev); if (WARN_ON(res < 0)) { dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n", __func__, res); } } /* Clear power up acknowledment. */ clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits); spin_lock_bh(&cfhsi->lock); /* Resume transmit if queue is not empty. */ if (!skb_peek(&cfhsi->qhead)) { dev_dbg(&cfhsi->ndev->dev, "%s: Peer wake, start timer.\n", __func__); /* Start inactivity timer. */ mod_timer(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT); spin_unlock_bh(&cfhsi->lock); return; } dev_dbg(&cfhsi->ndev->dev, "%s: Host wake.\n", __func__); spin_unlock_bh(&cfhsi->lock); /* Create HSI frame. */ len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi); if (likely(len > 0)) { /* Set up new transfer. */ res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev); if (WARN_ON(res < 0)) { dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n", __func__, res); cfhsi_abort_tx(cfhsi); } } else { dev_err(&cfhsi->ndev->dev, "%s: Failed to create HSI frame: %d.\n", __func__, len); } } static void cfhsi_wake_down(struct work_struct *work) { long ret; struct cfhsi *cfhsi = NULL; size_t fifo_occupancy; cfhsi = container_of(work, struct cfhsi, wake_down_work); dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) return; /* Check if there is something in FIFO. */ if (WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev, &fifo_occupancy))) fifo_occupancy = 0; if (fifo_occupancy) { dev_dbg(&cfhsi->ndev->dev, "%s: %u words in RX FIFO, restart timer.\n", __func__, (unsigned) fifo_occupancy); spin_lock_bh(&cfhsi->lock); mod_timer(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT); spin_unlock_bh(&cfhsi->lock); return; } /* Cancel pending RX requests */ cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev); /* Deactivate wake line. */ cfhsi->dev->cfhsi_wake_down(cfhsi->dev); /* Wait for acknowledge. */ ret = CFHSI_WAKEUP_TOUT; ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait, test_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits), ret); if (ret < 0) { /* Interrupted by signal. */ dev_info(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n", __func__, ret); return; } else if (!ret) { /* Timeout */ dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n", __func__); } /* Clear power down acknowledment. */ clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits); clear_bit(CFHSI_AWAKE, &cfhsi->bits); /* Check if there is something in FIFO. */ if (WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev, &fifo_occupancy))) fifo_occupancy = 0; if (fifo_occupancy) { dev_dbg(&cfhsi->ndev->dev, "%s: %u words in RX FIFO, wakeup forced.\n", __func__, (unsigned) fifo_occupancy); if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits)) queue_work(cfhsi->wq, &cfhsi->wake_up_work); } else dev_dbg(&cfhsi->ndev->dev, "%s: Done.\n", __func__); } static void cfhsi_wake_up_cb(struct cfhsi_drv *drv) { struct cfhsi *cfhsi = NULL; cfhsi = container_of(drv, struct cfhsi, drv); dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits); wake_up_interruptible(&cfhsi->wake_up_wait); if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits)) return; /* Schedule wake up work queue if the peer initiates. */ if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits)) queue_work(cfhsi->wq, &cfhsi->wake_up_work); } static void cfhsi_wake_down_cb(struct cfhsi_drv *drv) { struct cfhsi *cfhsi = NULL; cfhsi = container_of(drv, struct cfhsi, drv); dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__); /* Initiating low power is only permitted by the host (us). */ set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits); wake_up_interruptible(&cfhsi->wake_down_wait); } static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev) { struct cfhsi *cfhsi = NULL; int start_xfer = 0; int timer_active; if (!dev) return -EINVAL; cfhsi = netdev_priv(dev); spin_lock_bh(&cfhsi->lock); skb_queue_tail(&cfhsi->qhead, skb); /* Sanity check; xmit should not be called after unregister_netdev */ if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) { spin_unlock_bh(&cfhsi->lock); cfhsi_abort_tx(cfhsi); return -EINVAL; } /* Send flow off if number of packets is above high water mark. */ if (!cfhsi->flow_off_sent && cfhsi->qhead.qlen > cfhsi->q_high_mark && cfhsi->cfdev.flowctrl) { cfhsi->flow_off_sent = 1; cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF); } if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) { cfhsi->tx_state = CFHSI_TX_STATE_XFER; start_xfer = 1; } spin_unlock_bh(&cfhsi->lock); if (!start_xfer) return 0; /* Delete inactivity timer if started. */ #ifdef CONFIG_SMP timer_active = del_timer_sync(&cfhsi->timer); #else timer_active = del_timer(&cfhsi->timer); #endif /* CONFIG_SMP */ if (timer_active) { struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf; int len; int res; /* Create HSI frame. */ len = cfhsi_tx_frm(desc, cfhsi); BUG_ON(!len); /* Set up new transfer. */ res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev); if (WARN_ON(res < 0)) { dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n", __func__, res); cfhsi_abort_tx(cfhsi); } } else { /* Schedule wake up work queue if the we initiate. */ if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits)) queue_work(cfhsi->wq, &cfhsi->wake_up_work); } return 0; } static int cfhsi_open(struct net_device *dev) { netif_wake_queue(dev); return 0; } static int cfhsi_close(struct net_device *dev) { netif_stop_queue(dev); return 0; } static const struct net_device_ops cfhsi_ops = { .ndo_open = cfhsi_open, .ndo_stop = cfhsi_close, .ndo_start_xmit = cfhsi_xmit }; static void cfhsi_setup(struct net_device *dev) { struct cfhsi *cfhsi = netdev_priv(dev); dev->features = 0; dev->netdev_ops = &cfhsi_ops; dev->type = ARPHRD_CAIF; dev->flags = IFF_POINTOPOINT | IFF_NOARP; dev->mtu = CFHSI_MAX_PAYLOAD_SZ; dev->tx_queue_len = 0; dev->destructor = free_netdev; skb_queue_head_init(&cfhsi->qhead); cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW; cfhsi->cfdev.use_frag = false; cfhsi->cfdev.use_stx = false; cfhsi->cfdev.use_fcs = false; cfhsi->ndev = dev; } int cfhsi_probe(struct platform_device *pdev) { struct cfhsi *cfhsi = NULL; struct net_device *ndev; struct cfhsi_dev *dev; int res; ndev = alloc_netdev(sizeof(struct cfhsi), "cfhsi%d", cfhsi_setup); if (!ndev) { dev_err(&pdev->dev, "%s: alloc_netdev failed.\n", __func__); return -ENODEV; } cfhsi = netdev_priv(ndev); cfhsi->ndev = ndev; cfhsi->pdev = pdev; /* Initialize state vaiables. */ cfhsi->tx_state = CFHSI_TX_STATE_IDLE; cfhsi->rx_state = CFHSI_RX_STATE_DESC; /* Set flow info */ cfhsi->flow_off_sent = 0; cfhsi->q_low_mark = LOW_WATER_MARK; cfhsi->q_high_mark = HIGH_WATER_MARK; /* Assign the HSI device. */ dev = (struct cfhsi_dev *)pdev->dev.platform_data; cfhsi->dev = dev; /* Assign the driver to this HSI device. */ dev->drv = &cfhsi->drv; /* * Allocate a TX buffer with the size of a HSI packet descriptors * and the necessary room for CAIF payload frames. */ cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL); if (!cfhsi->tx_buf) { dev_err(&ndev->dev, "%s: Failed to allocate TX buffer.\n", __func__); res = -ENODEV; goto err_alloc_tx; } /* * Allocate a RX buffer with the size of two HSI packet descriptors and * the necessary room for CAIF payload frames. */ cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL); if (!cfhsi->rx_buf) { dev_err(&ndev->dev, "%s: Failed to allocate RX buffer.\n", __func__); res = -ENODEV; goto err_alloc_rx; } /* Initialize receive variables. */ cfhsi->rx_ptr = cfhsi->rx_buf; cfhsi->rx_len = CFHSI_DESC_SZ; /* Initialize spin locks. */ spin_lock_init(&cfhsi->lock); /* Set up the driver. */ cfhsi->drv.tx_done_cb = cfhsi_tx_done_cb; cfhsi->drv.rx_done_cb = cfhsi_rx_done_cb; /* Initialize the work queues. */ INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up); INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down); INIT_WORK(&cfhsi->rx_done_work, cfhsi_rx_done_work); INIT_WORK(&cfhsi->tx_done_work, cfhsi_tx_done_work); /* Clear all bit fields. */ clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits); clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits); clear_bit(CFHSI_WAKE_UP, &cfhsi->bits); clear_bit(CFHSI_AWAKE, &cfhsi->bits); clear_bit(CFHSI_PENDING_RX, &cfhsi->bits); /* Create work thread. */ cfhsi->wq = create_singlethread_workqueue(pdev->name); if (!cfhsi->wq) { dev_err(&ndev->dev, "%s: Failed to create work queue.\n", __func__); res = -ENODEV; goto err_create_wq; } /* Initialize wait queues. */ init_waitqueue_head(&cfhsi->wake_up_wait); init_waitqueue_head(&cfhsi->wake_down_wait); init_waitqueue_head(&cfhsi->flush_fifo_wait); /* Setup the inactivity timer. */ init_timer(&cfhsi->timer); cfhsi->timer.data = (unsigned long)cfhsi; cfhsi->timer.function = cfhsi_inactivity_tout; /* Add CAIF HSI device to list. */ spin_lock(&cfhsi_list_lock); list_add_tail(&cfhsi->list, &cfhsi_list); spin_unlock(&cfhsi_list_lock); /* Activate HSI interface. */ res = cfhsi->dev->cfhsi_up(cfhsi->dev); if (res) { dev_err(&cfhsi->ndev->dev, "%s: can't activate HSI interface: %d.\n", __func__, res); goto err_activate; } /* Flush FIFO */ res = cfhsi_flush_fifo(cfhsi); if (res) { dev_err(&ndev->dev, "%s: Can't flush FIFO: %d.\n", __func__, res); goto err_net_reg; } cfhsi->drv.wake_up_cb = cfhsi_wake_up_cb; cfhsi->drv.wake_down_cb = cfhsi_wake_down_cb; /* Register network device. */ res = register_netdev(ndev); if (res) { dev_err(&ndev->dev, "%s: Registration error: %d.\n", __func__, res); goto err_net_reg; } netif_stop_queue(ndev); return res; err_net_reg: cfhsi->dev->cfhsi_down(cfhsi->dev); err_activate: destroy_workqueue(cfhsi->wq); err_create_wq: kfree(cfhsi->rx_buf); err_alloc_rx: kfree(cfhsi->tx_buf); err_alloc_tx: free_netdev(ndev); return res; } static void cfhsi_shutdown(struct cfhsi *cfhsi, bool remove_platform_dev) { u8 *tx_buf, *rx_buf; /* Stop TXing */ netif_tx_stop_all_queues(cfhsi->ndev); /* going to shutdown driver */ set_bit(CFHSI_SHUTDOWN, &cfhsi->bits); if (remove_platform_dev) { /* Flush workqueue */ flush_workqueue(cfhsi->wq); /* Notify device. */ platform_device_unregister(cfhsi->pdev); } /* Flush workqueue */ flush_workqueue(cfhsi->wq); /* Delete timer if pending */ #ifdef CONFIG_SMP del_timer_sync(&cfhsi->timer); #else del_timer(&cfhsi->timer); #endif /* CONFIG_SMP */ /* Cancel pending RX request (if any) */ cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev); /* Flush again and destroy workqueue */ destroy_workqueue(cfhsi->wq); /* Store bufferes: will be freed later. */ tx_buf = cfhsi->tx_buf; rx_buf = cfhsi->rx_buf; /* Flush transmit queues. */ cfhsi_abort_tx(cfhsi); /* Deactivate interface */ cfhsi->dev->cfhsi_down(cfhsi->dev); /* Finally unregister the network device. */ unregister_netdev(cfhsi->ndev); /* Free buffers. */ kfree(tx_buf); kfree(rx_buf); } int cfhsi_remove(struct platform_device *pdev) { struct list_head *list_node; struct list_head *n; struct cfhsi *cfhsi = NULL; struct cfhsi_dev *dev; dev = (struct cfhsi_dev *)pdev->dev.platform_data; spin_lock(&cfhsi_list_lock); list_for_each_safe(list_node, n, &cfhsi_list) { cfhsi = list_entry(list_node, struct cfhsi, list); /* Find the corresponding device. */ if (cfhsi->dev == dev) { /* Remove from list. */ list_del(list_node); spin_unlock(&cfhsi_list_lock); /* Shutdown driver. */ cfhsi_shutdown(cfhsi, false); return 0; } } spin_unlock(&cfhsi_list_lock); return -ENODEV; } struct platform_driver cfhsi_plat_drv = { .probe = cfhsi_probe, .remove = cfhsi_remove, .driver = { .name = "cfhsi", .owner = THIS_MODULE, }, }; static void __exit cfhsi_exit_module(void) { struct list_head *list_node; struct list_head *n; struct cfhsi *cfhsi = NULL; spin_lock(&cfhsi_list_lock); list_for_each_safe(list_node, n, &cfhsi_list) { cfhsi = list_entry(list_node, struct cfhsi, list); /* Remove from list. */ list_del(list_node); spin_unlock(&cfhsi_list_lock); /* Shutdown driver. */ cfhsi_shutdown(cfhsi, true); spin_lock(&cfhsi_list_lock); } spin_unlock(&cfhsi_list_lock); /* Unregister platform driver. */ platform_driver_unregister(&cfhsi_plat_drv); } static int __init cfhsi_init_module(void) { int result; /* Initialize spin lock. */ spin_lock_init(&cfhsi_list_lock); /* Register platform driver. */ result = platform_driver_register(&cfhsi_plat_drv); if (result) { printk(KERN_ERR "Could not register platform HSI driver: %d.\n", result); goto err_dev_register; } return result; err_dev_register: return result; } module_init(cfhsi_init_module); module_exit(cfhsi_exit_module);