diff options
Diffstat (limited to 'drivers/net/caif/caif_spi.c')
-rw-r--r-- | drivers/net/caif/caif_spi.c | 850 |
1 files changed, 850 insertions, 0 deletions
diff --git a/drivers/net/caif/caif_spi.c b/drivers/net/caif/caif_spi.c new file mode 100644 index 0000000..f5058ff --- /dev/null +++ b/drivers/net/caif/caif_spi.c @@ -0,0 +1,850 @@ +/* + * Copyright (C) ST-Ericsson AB 2010 + * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com + * Author: Daniel Martensson / Daniel.Martensson@stericsson.com + * License terms: GNU General Public License (GPL) version 2. + */ + +#include <linux/version.h> +#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<daniel.martensson@stericsson.com>"); +MODULE_DESCRIPTION("CAIF SPI driver"); + +static int 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. */ +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 int dbgfs_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return 0; +} + +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, + (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 = dbgfs_open, + .read = dbgfs_state, + .owner = THIS_MODULE +}; + +static const struct file_operations dbgfs_frame_fops = { + .open = dbgfs_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); + + 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) { + spad = 1 + ((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 = (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 commited 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) + spad = 1 + ((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 = (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); + } + } 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; + + 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. */ + 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) { + 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); + skb->dev = cfspi->ndev; + + /* + * 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 = (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 const struct net_device_ops cfspi_ops = { + .ndo_open = cfspi_open, + .ndo_stop = cfspi_close, + .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", cfspi_setup); + if (!dev) + return -ENODEV; + + cfspi = netdev_priv(ndev); + netif_stop_queue(ndev); + cfspi->ndev = ndev; + cfspi->pdev = pdev; + + /* Set flow info */ + cfspi->flow_off_sent = 0; + cfspi->qd_low_mark = LOW_WATER_MARK; + cfspi->qd_high_mark = HIGH_WATER_MARK; + + /* Assign the SPI device. */ + cfspi->dev = dev; + /* Assign the device ifc to this SPI interface. */ + dev->ifc = &cfspi->ifc; + + /* Allocate DMA buffers. */ + cfspi->xfer.va_tx = dma_alloc(&cfspi->xfer.pa_tx); + if (!cfspi->xfer.va_tx) { + printk(KERN_WARNING + "CFSPI: failed to allocate dma TX buffer.\n"); + res = -ENODEV; + goto err_dma_alloc_tx; + } + + cfspi->xfer.va_rx = dma_alloc(&cfspi->xfer.pa_rx); + + if (!cfspi->xfer.va_rx) { + printk(KERN_WARNING + "CFSPI: failed to allocate dma TX buffer.\n"); + 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); + + /* 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: + dev_debugfs_rem(cfspi); + set_bit(SPI_TERMINATE, &cfspi->state); + wake_up_interruptible(&cfspi->wait); + destroy_workqueue(cfspi->wq); + err_create_wq: + dma_free(cfspi->xfer.va_rx, cfspi->xfer.pa_rx); + err_dma_alloc_rx: + dma_free(cfspi->xfer.va_tx, cfspi->xfer.pa_tx); + err_dma_alloc_tx: + free_netdev(ndev); + + return res; +} + +int cfspi_spi_remove(struct platform_device *pdev) +{ + struct list_head *list_node; + struct list_head *n; + struct cfspi *cfspi = NULL; + struct cfspi_dev *dev; + + dev = (struct cfspi_dev *)pdev->dev.platform_data; + spin_lock(&cfspi_list_lock); + list_for_each_safe(list_node, n, &cfspi_list) { + cfspi = list_entry(list_node, struct cfspi, list); + /* Find the corresponding device. */ + if (cfspi->dev == dev) { + /* Remove from list. */ + list_del(list_node); + /* Free DMA buffers. */ + dma_free(cfspi->xfer.va_rx, cfspi->xfer.pa_rx); + dma_free(cfspi->xfer.va_tx, cfspi->xfer.pa_tx); + set_bit(SPI_TERMINATE, &cfspi->state); + wake_up_interruptible(&cfspi->wait); + destroy_workqueue(cfspi->wq); + /* Destroy debugfs directory and files. */ + dev_debugfs_rem(cfspi); + unregister_netdev(cfspi->ndev); + spin_unlock(&cfspi_list_lock); + return 0; + } + } + spin_unlock(&cfspi_list_lock); + return -ENODEV; +} + +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); + platform_device_unregister(cfspi->pdev); + } + + /* 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: + err_dev_register: + return result; +} + +module_init(cfspi_init_module); +module_exit(cfspi_exit_module); |