--- /dev/null
+/*
+ * OMAP STI/XTI communications interface via netlink socket.
+ *
+ * Copyright (C) 2004, 2005, 2006 Nokia Corporation
+ * Written by: Paul Mundt <paul.mundt@nokia.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/netlink.h>
+#include <linux/socket.h>
+#include <linux/skbuff.h>
+#include <linux/mutex.h>
+#include <net/sock.h>
+#include <mach/sti.h>
+
+static struct sock *sti_sock;
+static DEFINE_MUTEX(sti_netlink_mutex);
+
+enum {
+ STI_READ,
+ STI_WRITE,
+};
+
+#if defined(CONFIG_ARCH_OMAP1) || defined(CONFIG_ARCH_OMAP2)
+static int sti_netlink_read(int pid, int seq, void *payload, int size)
+{
+ struct sk_buff *skb;
+ struct nlmsghdr *nlh;
+ int ret, len = NLMSG_SPACE(size);
+ unsigned char *tail;
+
+ skb = alloc_skb(len, GFP_KERNEL);
+ if (!skb)
+ return -ENOMEM;
+
+ tail = skb->tail;
+ nlh = NLMSG_PUT(skb, pid, seq, STI_READ,
+ len - (sizeof(struct nlmsghdr)));
+ nlh->nlmsg_flags = 0;
+ memcpy(NLMSG_DATA(nlh), payload, size);
+ nlh->nlmsg_len = skb->tail - tail;
+
+ ret = netlink_unicast(sti_sock, skb, pid, MSG_DONTWAIT);
+ if (ret > 0)
+ ret = 0;
+
+ return ret;
+
+nlmsg_failure:
+ if (skb)
+ kfree_skb(skb);
+
+ return -EINVAL;
+}
+#endif
+
+/*
+ * We abuse nlmsg_type and nlmsg_flags for our purposes.
+ *
+ * The ID is encoded into the upper 8 bits of the nlmsg_type, while the
+ * channel number is encoded into the upper 8 bits of the nlmsg_flags.
+ */
+static int sti_netlink_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ void *data;
+ u8 chan, id;
+ int size;
+ int ret = 0, len = 0;
+
+ data = NLMSG_DATA(nlh);
+ chan = (nlh->nlmsg_flags >> 8) & 0xff;
+ id = (nlh->nlmsg_type >> 8) & 0xff;
+ size = (int)(nlh->nlmsg_len - ((char *)data - (char *)nlh));
+
+ switch (nlh->nlmsg_type & 0xff) {
+ case STI_WRITE:
+ sti_channel_write_trace(size, id, data, chan);
+ break;
+#if defined(CONFIG_ARCH_OMAP1) || defined(CONFIG_ARCH_OMAP2)
+ case STI_READ:
+ data = kmalloc(size, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ memset(data, 0, size);
+
+ len = sti_read_packet(data, size);
+ ret = sti_netlink_read(NETLINK_CB(skb).pid, nlh->nlmsg_seq,
+ data, len);
+ kfree(data);
+ break;
+#endif
+ default:
+ return -ENOTTY;
+ }
+
+ return ret;
+}
+
+static int sti_netlink_receive_skb(struct sk_buff *skb)
+{
+ while (skb->len >= NLMSG_SPACE(0)) {
+ struct nlmsghdr *nlh;
+ u32 rlen;
+ int ret;
+
+ nlh = (struct nlmsghdr *)skb->data;
+ if (nlh->nlmsg_len < sizeof(struct nlmsghdr) ||
+ skb->len < nlh->nlmsg_len)
+ break;
+
+ rlen = NLMSG_ALIGN(nlh->nlmsg_len);
+ if (rlen > skb->len)
+ rlen = skb->len;
+
+ ret = sti_netlink_receive_msg(skb, nlh);
+ if (ret)
+ netlink_ack(skb, nlh, -ret);
+ else if (nlh->nlmsg_flags & NLM_F_ACK)
+ netlink_ack(skb, nlh, 0);
+
+ skb_pull(skb, rlen);
+ }
+
+ return 0;
+}
+
+static void sti_netlink_receive(struct sk_buff *skb)
+{
+ if (!mutex_trylock(&sti_netlink_mutex))
+ return;
+
+ sti_netlink_receive_skb(skb);
+ mutex_unlock(&sti_netlink_mutex);
+}
+
+static int __init sti_netlink_init(void)
+{
+ sti_sock = netlink_kernel_create(&init_net, NETLINK_USERSOCK, 0,
+ sti_netlink_receive, NULL,
+ THIS_MODULE);
+ if (!sti_sock) {
+ printk(KERN_ERR "STI: Failed to create netlink socket\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+module_init(sti_netlink_init);
+
+MODULE_AUTHOR("Paul Mundt");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("STI netlink-driven communications interface");