Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / caif / caif_spi.c
diff --git a/kernel/drivers/net/caif/caif_spi.c b/kernel/drivers/net/caif/caif_spi.c
new file mode 100644 (file)
index 0000000..72ea9ff
--- /dev/null
@@ -0,0 +1,871 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:  Daniel Martensson
+ * License terms: GNU General Public License (GPL) version 2.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <linux/workqueue.h>
+#include <linux/completion.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/debugfs.h>
+#include <linux/if_arp.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/caif_spi.h>
+
+#ifndef CONFIG_CAIF_SPI_SYNC
+#define FLAVOR "Flavour: Vanilla.\n"
+#else
+#define FLAVOR "Flavour: Master CMD&LEN at start.\n"
+#endif /* CONFIG_CAIF_SPI_SYNC */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Daniel Martensson");
+MODULE_DESCRIPTION("CAIF SPI driver");
+
+/* Returns the number of padding bytes for alignment. */
+#define PAD_POW2(x, pow) ((((x)&((pow)-1))==0) ? 0 : (((pow)-((x)&((pow)-1)))))
+
+static bool spi_loop;
+module_param(spi_loop, bool, S_IRUGO);
+MODULE_PARM_DESC(spi_loop, "SPI running in loopback mode.");
+
+/* SPI frame alignment. */
+module_param(spi_frm_align, int, S_IRUGO);
+MODULE_PARM_DESC(spi_frm_align, "SPI frame alignment.");
+
+/*
+ * SPI padding options.
+ * Warning: must be a base of 2 (& operation used) and can not be zero !
+ */
+module_param(spi_up_head_align, int, S_IRUGO);
+MODULE_PARM_DESC(spi_up_head_align, "SPI uplink head alignment.");
+
+module_param(spi_up_tail_align, int, S_IRUGO);
+MODULE_PARM_DESC(spi_up_tail_align, "SPI uplink tail alignment.");
+
+module_param(spi_down_head_align, int, S_IRUGO);
+MODULE_PARM_DESC(spi_down_head_align, "SPI downlink head alignment.");
+
+module_param(spi_down_tail_align, int, S_IRUGO);
+MODULE_PARM_DESC(spi_down_tail_align, "SPI downlink tail alignment.");
+
+#ifdef CONFIG_ARM
+#define BYTE_HEX_FMT "%02X"
+#else
+#define BYTE_HEX_FMT "%02hhX"
+#endif
+
+#define SPI_MAX_PAYLOAD_SIZE 4096
+/*
+ * Threshold values for the SPI packet queue. Flowcontrol will be asserted
+ * when the number of packets exceeds HIGH_WATER_MARK. It will not be
+ * deasserted before the number of packets drops below LOW_WATER_MARK.
+ */
+#define LOW_WATER_MARK   100
+#define HIGH_WATER_MARK  (LOW_WATER_MARK*5)
+
+#ifdef CONFIG_UML
+
+/*
+ * We sometimes use UML for debugging, but it cannot handle
+ * dma_alloc_coherent so we have to wrap it.
+ */
+static inline void *dma_alloc(dma_addr_t *daddr)
+{
+       return kmalloc(SPI_DMA_BUF_LEN, GFP_KERNEL);
+}
+
+static inline void dma_free(void *cpu_addr, dma_addr_t handle)
+{
+       kfree(cpu_addr);
+}
+
+#else
+
+static inline void *dma_alloc(dma_addr_t *daddr)
+{
+       return dma_alloc_coherent(NULL, SPI_DMA_BUF_LEN, daddr,
+                               GFP_KERNEL);
+}
+
+static inline void dma_free(void *cpu_addr, dma_addr_t handle)
+{
+       dma_free_coherent(NULL, SPI_DMA_BUF_LEN, cpu_addr, handle);
+}
+#endif /* CONFIG_UML */
+
+#ifdef CONFIG_DEBUG_FS
+
+#define DEBUGFS_BUF_SIZE       4096
+
+static struct dentry *dbgfs_root;
+
+static inline void driver_debugfs_create(void)
+{
+       dbgfs_root = debugfs_create_dir(cfspi_spi_driver.driver.name, NULL);
+}
+
+static inline void driver_debugfs_remove(void)
+{
+       debugfs_remove(dbgfs_root);
+}
+
+static inline void dev_debugfs_rem(struct cfspi *cfspi)
+{
+       debugfs_remove(cfspi->dbgfs_frame);
+       debugfs_remove(cfspi->dbgfs_state);
+       debugfs_remove(cfspi->dbgfs_dir);
+}
+
+static ssize_t dbgfs_state(struct file *file, char __user *user_buf,
+                          size_t count, loff_t *ppos)
+{
+       char *buf;
+       int len = 0;
+       ssize_t size;
+       struct cfspi *cfspi = file->private_data;
+
+       buf = kzalloc(DEBUGFS_BUF_SIZE, GFP_KERNEL);
+       if (!buf)
+               return 0;
+
+       /* Print out debug information. */
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "CAIF SPI debug information:\n");
+
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), FLAVOR);
+
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "STATE: %d\n", cfspi->dbg_state);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Previous CMD: 0x%x\n", cfspi->pcmd);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Current CMD: 0x%x\n", cfspi->cmd);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Previous TX len: %d\n", cfspi->tx_ppck_len);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Previous RX len: %d\n", cfspi->rx_ppck_len);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Current TX len: %d\n", cfspi->tx_cpck_len);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Current RX len: %d\n", cfspi->rx_cpck_len);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Next TX len: %d\n", cfspi->tx_npck_len);
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Next RX len: %d\n", cfspi->rx_npck_len);
+
+       if (len > DEBUGFS_BUF_SIZE)
+               len = DEBUGFS_BUF_SIZE;
+
+       size = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+       kfree(buf);
+
+       return size;
+}
+
+static ssize_t print_frame(char *buf, size_t size, char *frm,
+                          size_t count, size_t cut)
+{
+       int len = 0;
+       int i;
+       for (i = 0; i < count; i++) {
+               len += snprintf((buf + len), (size - len),
+                                       "[0x" BYTE_HEX_FMT "]",
+                                       frm[i]);
+               if ((i == cut) && (count > (cut * 2))) {
+                       /* Fast forward. */
+                       i = count - cut;
+                       len += snprintf((buf + len), (size - len),
+                                       "--- %u bytes skipped ---\n",
+                                       (int)(count - (cut * 2)));
+               }
+
+               if ((!(i % 10)) && i) {
+                       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                                       "\n");
+               }
+       }
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), "\n");
+       return len;
+}
+
+static ssize_t dbgfs_frame(struct file *file, char __user *user_buf,
+                          size_t count, loff_t *ppos)
+{
+       char *buf;
+       int len = 0;
+       ssize_t size;
+       struct cfspi *cfspi;
+
+       cfspi = file->private_data;
+       buf = kzalloc(DEBUGFS_BUF_SIZE, GFP_KERNEL);
+       if (!buf)
+               return 0;
+
+       /* Print out debug information. */
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Current frame:\n");
+
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Tx data (Len: %d):\n", cfspi->tx_cpck_len);
+
+       len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len),
+                          cfspi->xfer.va_tx[0],
+                          (cfspi->tx_cpck_len + SPI_CMD_SZ), 100);
+
+       len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
+                       "Rx data (Len: %d):\n", cfspi->rx_cpck_len);
+
+       len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len),
+                          cfspi->xfer.va_rx,
+                          (cfspi->rx_cpck_len + SPI_CMD_SZ), 100);
+
+       size = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+       kfree(buf);
+
+       return size;
+}
+
+static const struct file_operations dbgfs_state_fops = {
+       .open = simple_open,
+       .read = dbgfs_state,
+       .owner = THIS_MODULE
+};
+
+static const struct file_operations dbgfs_frame_fops = {
+       .open = simple_open,
+       .read = dbgfs_frame,
+       .owner = THIS_MODULE
+};
+
+static inline void dev_debugfs_add(struct cfspi *cfspi)
+{
+       cfspi->dbgfs_dir = debugfs_create_dir(cfspi->pdev->name, dbgfs_root);
+       cfspi->dbgfs_state = debugfs_create_file("state", S_IRUGO,
+                                                cfspi->dbgfs_dir, cfspi,
+                                                &dbgfs_state_fops);
+       cfspi->dbgfs_frame = debugfs_create_file("frame", S_IRUGO,
+                                                cfspi->dbgfs_dir, cfspi,
+                                                &dbgfs_frame_fops);
+}
+
+inline void cfspi_dbg_state(struct cfspi *cfspi, int state)
+{
+       cfspi->dbg_state = state;
+};
+#else
+
+static inline void driver_debugfs_create(void)
+{
+}
+
+static inline void driver_debugfs_remove(void)
+{
+}
+
+static inline void dev_debugfs_add(struct cfspi *cfspi)
+{
+}
+
+static inline void dev_debugfs_rem(struct cfspi *cfspi)
+{
+}
+
+inline void cfspi_dbg_state(struct cfspi *cfspi, int state)
+{
+}
+#endif                         /* CONFIG_DEBUG_FS */
+
+static LIST_HEAD(cfspi_list);
+static spinlock_t cfspi_list_lock;
+
+/* SPI uplink head alignment. */
+static ssize_t show_up_head_align(struct device_driver *driver, char *buf)
+{
+       return sprintf(buf, "%d\n", spi_up_head_align);
+}
+
+static DRIVER_ATTR(up_head_align, S_IRUSR, show_up_head_align, NULL);
+
+/* SPI uplink tail alignment. */
+static ssize_t show_up_tail_align(struct device_driver *driver, char *buf)
+{
+       return sprintf(buf, "%d\n", spi_up_tail_align);
+}
+
+static DRIVER_ATTR(up_tail_align, S_IRUSR, show_up_tail_align, NULL);
+
+/* SPI downlink head alignment. */
+static ssize_t show_down_head_align(struct device_driver *driver, char *buf)
+{
+       return sprintf(buf, "%d\n", spi_down_head_align);
+}
+
+static DRIVER_ATTR(down_head_align, S_IRUSR, show_down_head_align, NULL);
+
+/* SPI downlink tail alignment. */
+static ssize_t show_down_tail_align(struct device_driver *driver, char *buf)
+{
+       return sprintf(buf, "%d\n", spi_down_tail_align);
+}
+
+static DRIVER_ATTR(down_tail_align, S_IRUSR, show_down_tail_align, NULL);
+
+/* SPI frame alignment. */
+static ssize_t show_frame_align(struct device_driver *driver, char *buf)
+{
+       return sprintf(buf, "%d\n", spi_frm_align);
+}
+
+static DRIVER_ATTR(frame_align, S_IRUSR, show_frame_align, NULL);
+
+int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len)
+{
+       u8 *dst = buf;
+       caif_assert(buf);
+
+       if (cfspi->slave && !cfspi->slave_talked)
+               cfspi->slave_talked = true;
+
+       do {
+               struct sk_buff *skb;
+               struct caif_payload_info *info;
+               int spad = 0;
+               int epad;
+
+               skb = skb_dequeue(&cfspi->chead);
+               if (!skb)
+                       break;
+
+               /*
+                * Calculate length of frame including SPI padding.
+                * The payload position is found in the control buffer.
+                */
+               info = (struct caif_payload_info *)&skb->cb;
+
+               /*
+                * Compute head offset i.e. number of bytes to add to
+                * get the start of the payload aligned.
+                */
+               if (spi_up_head_align > 1) {
+                       spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
+                       *dst = (u8)(spad - 1);
+                       dst += spad;
+               }
+
+               /* Copy in CAIF frame. */
+               skb_copy_bits(skb, 0, dst, skb->len);
+               dst += skb->len;
+               cfspi->ndev->stats.tx_packets++;
+               cfspi->ndev->stats.tx_bytes += skb->len;
+
+               /*
+                * Compute tail offset i.e. number of bytes to add to
+                * get the complete CAIF frame aligned.
+                */
+               epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
+               dst += epad;
+
+               dev_kfree_skb(skb);
+
+       } while ((dst - buf) < len);
+
+       return dst - buf;
+}
+
+int cfspi_xmitlen(struct cfspi *cfspi)
+{
+       struct sk_buff *skb = NULL;
+       int frm_len = 0;
+       int pkts = 0;
+
+       /*
+        * Decommit previously committed frames.
+        * skb_queue_splice_tail(&cfspi->chead,&cfspi->qhead)
+        */
+       while (skb_peek(&cfspi->chead)) {
+               skb = skb_dequeue_tail(&cfspi->chead);
+               skb_queue_head(&cfspi->qhead, skb);
+       }
+
+       do {
+               struct caif_payload_info *info = NULL;
+               int spad = 0;
+               int epad = 0;
+
+               skb = skb_dequeue(&cfspi->qhead);
+               if (!skb)
+                       break;
+
+               /*
+                * Calculate length of frame including SPI padding.
+                * The payload position is found in the control buffer.
+                */
+               info = (struct caif_payload_info *)&skb->cb;
+
+               /*
+                * Compute head offset i.e. number of bytes to add to
+                * get the start of the payload aligned.
+                */
+               if (spi_up_head_align > 1)
+                       spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
+
+               /*
+                * Compute tail offset i.e. number of bytes to add to
+                * get the complete CAIF frame aligned.
+                */
+               epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
+
+               if ((skb->len + spad + epad + frm_len) <= CAIF_MAX_SPI_FRAME) {
+                       skb_queue_tail(&cfspi->chead, skb);
+                       pkts++;
+                       frm_len += skb->len + spad + epad;
+               } else {
+                       /* Put back packet. */
+                       skb_queue_head(&cfspi->qhead, skb);
+                       break;
+               }
+       } while (pkts <= CAIF_MAX_SPI_PKTS);
+
+       /*
+        * Send flow on if previously sent flow off
+        * and now go below the low water mark
+        */
+       if (cfspi->flow_off_sent && cfspi->qhead.qlen < cfspi->qd_low_mark &&
+               cfspi->cfdev.flowctrl) {
+               cfspi->flow_off_sent = 0;
+               cfspi->cfdev.flowctrl(cfspi->ndev, 1);
+       }
+
+       return frm_len;
+}
+
+static void cfspi_ss_cb(bool assert, struct cfspi_ifc *ifc)
+{
+       struct cfspi *cfspi = (struct cfspi *)ifc->priv;
+
+       /*
+        * The slave device is the master on the link. Interrupts before the
+        * slave has transmitted are considered spurious.
+        */
+       if (cfspi->slave && !cfspi->slave_talked) {
+               printk(KERN_WARNING "CFSPI: Spurious SS interrupt.\n");
+               return;
+       }
+
+       if (!in_interrupt())
+               spin_lock(&cfspi->lock);
+       if (assert) {
+               set_bit(SPI_SS_ON, &cfspi->state);
+               set_bit(SPI_XFER, &cfspi->state);
+       } else {
+               set_bit(SPI_SS_OFF, &cfspi->state);
+       }
+       if (!in_interrupt())
+               spin_unlock(&cfspi->lock);
+
+       /* Wake up the xfer thread. */
+       if (assert)
+               wake_up_interruptible(&cfspi->wait);
+}
+
+static void cfspi_xfer_done_cb(struct cfspi_ifc *ifc)
+{
+       struct cfspi *cfspi = (struct cfspi *)ifc->priv;
+
+       /* Transfer done, complete work queue */
+       complete(&cfspi->comp);
+}
+
+static int cfspi_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct cfspi *cfspi = NULL;
+       unsigned long flags;
+       if (!dev)
+               return -EINVAL;
+
+       cfspi = netdev_priv(dev);
+
+       skb_queue_tail(&cfspi->qhead, skb);
+
+       spin_lock_irqsave(&cfspi->lock, flags);
+       if (!test_and_set_bit(SPI_XFER, &cfspi->state)) {
+               /* Wake up xfer thread. */
+               wake_up_interruptible(&cfspi->wait);
+       }
+       spin_unlock_irqrestore(&cfspi->lock, flags);
+
+       /* Send flow off if number of bytes is above high water mark */
+       if (!cfspi->flow_off_sent &&
+               cfspi->qhead.qlen > cfspi->qd_high_mark &&
+               cfspi->cfdev.flowctrl) {
+               cfspi->flow_off_sent = 1;
+               cfspi->cfdev.flowctrl(cfspi->ndev, 0);
+       }
+
+       return 0;
+}
+
+int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len)
+{
+       u8 *src = buf;
+
+       caif_assert(buf != NULL);
+
+       do {
+               int res;
+               struct sk_buff *skb = NULL;
+               int spad = 0;
+               int epad = 0;
+               u8 *dst = NULL;
+               int pkt_len = 0;
+
+               /*
+                * Compute head offset i.e. number of bytes added to
+                * get the start of the payload aligned.
+                */
+               if (spi_down_head_align > 1) {
+                       spad = 1 + *src;
+                       src += spad;
+               }
+
+               /* Read length of CAIF frame (little endian). */
+               pkt_len = *src;
+               pkt_len |= ((*(src+1)) << 8) & 0xFF00;
+               pkt_len += 2;   /* Add FCS fields. */
+
+               /* Get a suitable caif packet and copy in data. */
+
+               skb = netdev_alloc_skb(cfspi->ndev, pkt_len + 1);
+               caif_assert(skb != NULL);
+
+               dst = skb_put(skb, pkt_len);
+               memcpy(dst, src, pkt_len);
+               src += pkt_len;
+
+               skb->protocol = htons(ETH_P_CAIF);
+               skb_reset_mac_header(skb);
+
+               /*
+                * Push received packet up the stack.
+                */
+               if (!spi_loop)
+                       res = netif_rx_ni(skb);
+               else
+                       res = cfspi_xmit(skb, cfspi->ndev);
+
+               if (!res) {
+                       cfspi->ndev->stats.rx_packets++;
+                       cfspi->ndev->stats.rx_bytes += pkt_len;
+               } else
+                       cfspi->ndev->stats.rx_dropped++;
+
+               /*
+                * Compute tail offset i.e. number of bytes added to
+                * get the complete CAIF frame aligned.
+                */
+               epad = PAD_POW2((pkt_len + spad), spi_down_tail_align);
+               src += epad;
+       } while ((src - buf) < len);
+
+       return src - buf;
+}
+
+static int cfspi_open(struct net_device *dev)
+{
+       netif_wake_queue(dev);
+       return 0;
+}
+
+static int cfspi_close(struct net_device *dev)
+{
+       netif_stop_queue(dev);
+       return 0;
+}
+
+static int cfspi_init(struct net_device *dev)
+{
+       int res = 0;
+       struct cfspi *cfspi = netdev_priv(dev);
+
+       /* Set flow info. */
+       cfspi->flow_off_sent = 0;
+       cfspi->qd_low_mark = LOW_WATER_MARK;
+       cfspi->qd_high_mark = HIGH_WATER_MARK;
+
+       /* Set slave info. */
+       if (!strncmp(cfspi_spi_driver.driver.name, "cfspi_sspi", 10)) {
+               cfspi->slave = true;
+               cfspi->slave_talked = false;
+       } else {
+               cfspi->slave = false;
+               cfspi->slave_talked = false;
+       }
+
+       /* Allocate DMA buffers. */
+       cfspi->xfer.va_tx[0] = dma_alloc(&cfspi->xfer.pa_tx[0]);
+       if (!cfspi->xfer.va_tx[0]) {
+               res = -ENODEV;
+               goto err_dma_alloc_tx_0;
+       }
+
+       cfspi->xfer.va_rx = dma_alloc(&cfspi->xfer.pa_rx);
+
+       if (!cfspi->xfer.va_rx) {
+               res = -ENODEV;
+               goto err_dma_alloc_rx;
+       }
+
+       /* Initialize the work queue. */
+       INIT_WORK(&cfspi->work, cfspi_xfer);
+
+       /* Initialize spin locks. */
+       spin_lock_init(&cfspi->lock);
+
+       /* Initialize flow control state. */
+       cfspi->flow_stop = false;
+
+       /* Initialize wait queue. */
+       init_waitqueue_head(&cfspi->wait);
+
+       /* Create work thread. */
+       cfspi->wq = create_singlethread_workqueue(dev->name);
+       if (!cfspi->wq) {
+               printk(KERN_WARNING "CFSPI: failed to create work queue.\n");
+               res = -ENODEV;
+               goto err_create_wq;
+       }
+
+       /* Initialize work queue. */
+       init_completion(&cfspi->comp);
+
+       /* Create debugfs entries. */
+       dev_debugfs_add(cfspi);
+
+       /* Set up the ifc. */
+       cfspi->ifc.ss_cb = cfspi_ss_cb;
+       cfspi->ifc.xfer_done_cb = cfspi_xfer_done_cb;
+       cfspi->ifc.priv = cfspi;
+
+       /* Add CAIF SPI device to list. */
+       spin_lock(&cfspi_list_lock);
+       list_add_tail(&cfspi->list, &cfspi_list);
+       spin_unlock(&cfspi_list_lock);
+
+       /* Schedule the work queue. */
+       queue_work(cfspi->wq, &cfspi->work);
+
+       return 0;
+
+ err_create_wq:
+       dma_free(cfspi->xfer.va_rx, cfspi->xfer.pa_rx);
+ err_dma_alloc_rx:
+       dma_free(cfspi->xfer.va_tx[0], cfspi->xfer.pa_tx[0]);
+ err_dma_alloc_tx_0:
+       return res;
+}
+
+static void cfspi_uninit(struct net_device *dev)
+{
+       struct cfspi *cfspi = netdev_priv(dev);
+
+       /* Remove from list. */
+       spin_lock(&cfspi_list_lock);
+       list_del(&cfspi->list);
+       spin_unlock(&cfspi_list_lock);
+
+       cfspi->ndev = NULL;
+       /* Free DMA buffers. */
+       dma_free(cfspi->xfer.va_rx, cfspi->xfer.pa_rx);
+       dma_free(cfspi->xfer.va_tx[0], cfspi->xfer.pa_tx[0]);
+       set_bit(SPI_TERMINATE, &cfspi->state);
+       wake_up_interruptible(&cfspi->wait);
+       destroy_workqueue(cfspi->wq);
+       /* Destroy debugfs directory and files. */
+       dev_debugfs_rem(cfspi);
+       return;
+}
+
+static const struct net_device_ops cfspi_ops = {
+       .ndo_open = cfspi_open,
+       .ndo_stop = cfspi_close,
+       .ndo_init = cfspi_init,
+       .ndo_uninit = cfspi_uninit,
+       .ndo_start_xmit = cfspi_xmit
+};
+
+static void cfspi_setup(struct net_device *dev)
+{
+       struct cfspi *cfspi = netdev_priv(dev);
+       dev->features = 0;
+       dev->netdev_ops = &cfspi_ops;
+       dev->type = ARPHRD_CAIF;
+       dev->flags = IFF_NOARP | IFF_POINTOPOINT;
+       dev->tx_queue_len = 0;
+       dev->mtu = SPI_MAX_PAYLOAD_SIZE;
+       dev->destructor = free_netdev;
+       skb_queue_head_init(&cfspi->qhead);
+       skb_queue_head_init(&cfspi->chead);
+       cfspi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
+       cfspi->cfdev.use_frag = false;
+       cfspi->cfdev.use_stx = false;
+       cfspi->cfdev.use_fcs = false;
+       cfspi->ndev = dev;
+}
+
+int cfspi_spi_probe(struct platform_device *pdev)
+{
+       struct cfspi *cfspi = NULL;
+       struct net_device *ndev;
+       struct cfspi_dev *dev;
+       int res;
+       dev = (struct cfspi_dev *)pdev->dev.platform_data;
+
+       ndev = alloc_netdev(sizeof(struct cfspi), "cfspi%d",
+                           NET_NAME_UNKNOWN, cfspi_setup);
+       if (!dev)
+               return -ENODEV;
+
+       cfspi = netdev_priv(ndev);
+       netif_stop_queue(ndev);
+       cfspi->ndev = ndev;
+       cfspi->pdev = pdev;
+
+       /* Assign the SPI device. */
+       cfspi->dev = dev;
+       /* Assign the device ifc to this SPI interface. */
+       dev->ifc = &cfspi->ifc;
+
+       /* Register network device. */
+       res = register_netdev(ndev);
+       if (res) {
+               printk(KERN_ERR "CFSPI: Reg. error: %d.\n", res);
+               goto err_net_reg;
+       }
+       return res;
+
+ err_net_reg:
+       free_netdev(ndev);
+
+       return res;
+}
+
+int cfspi_spi_remove(struct platform_device *pdev)
+{
+       /* Everything is done in cfspi_uninit(). */
+       return 0;
+}
+
+static void __exit cfspi_exit_module(void)
+{
+       struct list_head *list_node;
+       struct list_head *n;
+       struct cfspi *cfspi = NULL;
+
+       list_for_each_safe(list_node, n, &cfspi_list) {
+               cfspi = list_entry(list_node, struct cfspi, list);
+               unregister_netdev(cfspi->ndev);
+       }
+
+       /* Destroy sysfs files. */
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_up_head_align);
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_up_tail_align);
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_down_head_align);
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_down_tail_align);
+       driver_remove_file(&cfspi_spi_driver.driver, &driver_attr_frame_align);
+       /* Unregister platform driver. */
+       platform_driver_unregister(&cfspi_spi_driver);
+       /* Destroy debugfs root directory. */
+       driver_debugfs_remove();
+}
+
+static int __init cfspi_init_module(void)
+{
+       int result;
+
+       /* Initialize spin lock. */
+       spin_lock_init(&cfspi_list_lock);
+
+       /* Register platform driver. */
+       result = platform_driver_register(&cfspi_spi_driver);
+       if (result) {
+               printk(KERN_ERR "Could not register platform SPI driver.\n");
+               goto err_dev_register;
+       }
+
+       /* Create sysfs files. */
+       result =
+           driver_create_file(&cfspi_spi_driver.driver,
+                              &driver_attr_up_head_align);
+       if (result) {
+               printk(KERN_ERR "Sysfs creation failed 1.\n");
+               goto err_create_up_head_align;
+       }
+
+       result =
+           driver_create_file(&cfspi_spi_driver.driver,
+                              &driver_attr_up_tail_align);
+       if (result) {
+               printk(KERN_ERR "Sysfs creation failed 2.\n");
+               goto err_create_up_tail_align;
+       }
+
+       result =
+           driver_create_file(&cfspi_spi_driver.driver,
+                              &driver_attr_down_head_align);
+       if (result) {
+               printk(KERN_ERR "Sysfs creation failed 3.\n");
+               goto err_create_down_head_align;
+       }
+
+       result =
+           driver_create_file(&cfspi_spi_driver.driver,
+                              &driver_attr_down_tail_align);
+       if (result) {
+               printk(KERN_ERR "Sysfs creation failed 4.\n");
+               goto err_create_down_tail_align;
+       }
+
+       result =
+           driver_create_file(&cfspi_spi_driver.driver,
+                              &driver_attr_frame_align);
+       if (result) {
+               printk(KERN_ERR "Sysfs creation failed 5.\n");
+               goto err_create_frame_align;
+       }
+       driver_debugfs_create();
+       return result;
+
+ err_create_frame_align:
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_down_tail_align);
+ err_create_down_tail_align:
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_down_head_align);
+ err_create_down_head_align:
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_up_tail_align);
+ err_create_up_tail_align:
+       driver_remove_file(&cfspi_spi_driver.driver,
+                          &driver_attr_up_head_align);
+ err_create_up_head_align:
+       platform_driver_unregister(&cfspi_spi_driver);
+ err_dev_register:
+       return result;
+}
+
+module_init(cfspi_init_module);
+module_exit(cfspi_exit_module);