--- /dev/null
+/*
+ * Function Control Protocol (IEC 61883-1) helper functions
+ *
+ * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include <linux/device.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+#include "fcp.h"
+#include "lib.h"
+#include "amdtp.h"
+
+#define CTS_AVC 0x00
+
+#define ERROR_RETRIES 3
+#define ERROR_DELAY_MS 5
+#define FCP_TIMEOUT_MS 125
+
+int avc_general_set_sig_fmt(struct fw_unit *unit, unsigned int rate,
+ enum avc_general_plug_dir dir,
+ unsigned short pid)
+{
+ unsigned int sfc;
+ u8 *buf;
+ bool flag;
+ int err;
+
+ flag = false;
+ for (sfc = 0; sfc < CIP_SFC_COUNT; sfc++) {
+ if (amdtp_rate_table[sfc] == rate) {
+ flag = true;
+ break;
+ }
+ }
+ if (!flag)
+ return -EINVAL;
+
+ buf = kzalloc(8, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ buf[0] = 0x00; /* AV/C CONTROL */
+ buf[1] = 0xff; /* UNIT */
+ if (dir == AVC_GENERAL_PLUG_DIR_IN)
+ buf[2] = 0x19; /* INPUT PLUG SIGNAL FORMAT */
+ else
+ buf[2] = 0x18; /* OUTPUT PLUG SIGNAL FORMAT */
+ buf[3] = 0xff & pid; /* plug id */
+ buf[4] = 0x90; /* EOH_1, Form_1, FMT. AM824 */
+ buf[5] = 0x07 & sfc; /* FDF-hi. AM824, frequency */
+ buf[6] = 0xff; /* FDF-mid. AM824, SYT hi (not used)*/
+ buf[7] = 0xff; /* FDF-low. AM824, SYT lo (not used) */
+
+ /* do transaction and check buf[1-5] are the same against command */
+ err = fcp_avc_transaction(unit, buf, 8, buf, 8,
+ BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5));
+ if (err >= 0 && err < 8)
+ err = -EIO;
+ else if (buf[0] == 0x08) /* NOT IMPLEMENTED */
+ err = -ENOSYS;
+ else if (buf[0] == 0x0a) /* REJECTED */
+ err = -EINVAL;
+ if (err < 0)
+ goto end;
+
+ err = 0;
+end:
+ kfree(buf);
+ return err;
+}
+EXPORT_SYMBOL(avc_general_set_sig_fmt);
+
+int avc_general_get_sig_fmt(struct fw_unit *unit, unsigned int *rate,
+ enum avc_general_plug_dir dir,
+ unsigned short pid)
+{
+ unsigned int sfc;
+ u8 *buf;
+ int err;
+
+ buf = kzalloc(8, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ buf[0] = 0x01; /* AV/C STATUS */
+ buf[1] = 0xff; /* Unit */
+ if (dir == AVC_GENERAL_PLUG_DIR_IN)
+ buf[2] = 0x19; /* INPUT PLUG SIGNAL FORMAT */
+ else
+ buf[2] = 0x18; /* OUTPUT PLUG SIGNAL FORMAT */
+ buf[3] = 0xff & pid; /* plug id */
+ buf[4] = 0x90; /* EOH_1, Form_1, FMT. AM824 */
+ buf[5] = 0xff; /* FDF-hi. AM824, frequency */
+ buf[6] = 0xff; /* FDF-mid. AM824, SYT hi (not used) */
+ buf[7] = 0xff; /* FDF-low. AM824, SYT lo (not used) */
+
+ /* do transaction and check buf[1-4] are the same against command */
+ err = fcp_avc_transaction(unit, buf, 8, buf, 8,
+ BIT(1) | BIT(2) | BIT(3) | BIT(4));
+ if (err >= 0 && err < 8)
+ err = -EIO;
+ else if (buf[0] == 0x08) /* NOT IMPLEMENTED */
+ err = -ENOSYS;
+ else if (buf[0] == 0x0a) /* REJECTED */
+ err = -EINVAL;
+ else if (buf[0] == 0x0b) /* IN TRANSITION */
+ err = -EAGAIN;
+ if (err < 0)
+ goto end;
+
+ /* check sfc field and pick up rate */
+ sfc = 0x07 & buf[5];
+ if (sfc >= CIP_SFC_COUNT) {
+ err = -EAGAIN; /* also in transition */
+ goto end;
+ }
+
+ *rate = amdtp_rate_table[sfc];
+ err = 0;
+end:
+ kfree(buf);
+ return err;
+}
+EXPORT_SYMBOL(avc_general_get_sig_fmt);
+
+int avc_general_get_plug_info(struct fw_unit *unit, unsigned int subunit_type,
+ unsigned int subunit_id, unsigned int subfunction,
+ u8 info[AVC_PLUG_INFO_BUF_BYTES])
+{
+ u8 *buf;
+ int err;
+
+ /* extended subunit in spec.4.2 is not supported */
+ if ((subunit_type == 0x1E) || (subunit_id == 5))
+ return -EINVAL;
+
+ buf = kzalloc(8, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ buf[0] = 0x01; /* AV/C STATUS */
+ /* UNIT or Subunit, Functionblock */
+ buf[1] = ((subunit_type & 0x1f) << 3) | (subunit_id & 0x7);
+ buf[2] = 0x02; /* PLUG INFO */
+ buf[3] = 0xff & subfunction;
+
+ err = fcp_avc_transaction(unit, buf, 8, buf, 8, BIT(1) | BIT(2));
+ if (err >= 0 && err < 8)
+ err = -EIO;
+ else if (buf[0] == 0x08) /* NOT IMPLEMENTED */
+ err = -ENOSYS;
+ else if (buf[0] == 0x0a) /* REJECTED */
+ err = -EINVAL;
+ else if (buf[0] == 0x0b) /* IN TRANSITION */
+ err = -EAGAIN;
+ if (err < 0)
+ goto end;
+
+ info[0] = buf[4];
+ info[1] = buf[5];
+ info[2] = buf[6];
+ info[3] = buf[7];
+
+ err = 0;
+end:
+ kfree(buf);
+ return err;
+}
+EXPORT_SYMBOL(avc_general_get_plug_info);
+
+static DEFINE_SPINLOCK(transactions_lock);
+static LIST_HEAD(transactions);
+
+enum fcp_state {
+ STATE_PENDING,
+ STATE_BUS_RESET,
+ STATE_COMPLETE,
+ STATE_DEFERRED,
+};
+
+struct fcp_transaction {
+ struct list_head list;
+ struct fw_unit *unit;
+ void *response_buffer;
+ unsigned int response_size;
+ unsigned int response_match_bytes;
+ enum fcp_state state;
+ wait_queue_head_t wait;
+ bool deferrable;
+};
+
+/**
+ * fcp_avc_transaction - send an AV/C command and wait for its response
+ * @unit: a unit on the target device
+ * @command: a buffer containing the command frame; must be DMA-able
+ * @command_size: the size of @command
+ * @response: a buffer for the response frame
+ * @response_size: the maximum size of @response
+ * @response_match_bytes: a bitmap specifying the bytes used to detect the
+ * correct response frame
+ *
+ * This function sends a FCP command frame to the target and waits for the
+ * corresponding response frame to be returned.
+ *
+ * Because it is possible for multiple FCP transactions to be active at the
+ * same time, the correct response frame is detected by the value of certain
+ * bytes. These bytes must be set in @response before calling this function,
+ * and the corresponding bits must be set in @response_match_bytes.
+ *
+ * @command and @response can point to the same buffer.
+ *
+ * Returns the actual size of the response frame, or a negative error code.
+ */
+int fcp_avc_transaction(struct fw_unit *unit,
+ const void *command, unsigned int command_size,
+ void *response, unsigned int response_size,
+ unsigned int response_match_bytes)
+{
+ struct fcp_transaction t;
+ int tcode, ret, tries = 0;
+
+ t.unit = unit;
+ t.response_buffer = response;
+ t.response_size = response_size;
+ t.response_match_bytes = response_match_bytes;
+ t.state = STATE_PENDING;
+ init_waitqueue_head(&t.wait);
+
+ if (*(const u8 *)command == 0x00 || *(const u8 *)command == 0x03)
+ t.deferrable = true;
+
+ spin_lock_irq(&transactions_lock);
+ list_add_tail(&t.list, &transactions);
+ spin_unlock_irq(&transactions_lock);
+
+ for (;;) {
+ tcode = command_size == 4 ? TCODE_WRITE_QUADLET_REQUEST
+ : TCODE_WRITE_BLOCK_REQUEST;
+ ret = snd_fw_transaction(t.unit, tcode,
+ CSR_REGISTER_BASE + CSR_FCP_COMMAND,
+ (void *)command, command_size, 0);
+ if (ret < 0)
+ break;
+deferred:
+ wait_event_timeout(t.wait, t.state != STATE_PENDING,
+ msecs_to_jiffies(FCP_TIMEOUT_MS));
+
+ if (t.state == STATE_DEFERRED) {
+ /*
+ * 'AV/C General Specification' define no time limit
+ * on command completion once an INTERIM response has
+ * been sent. but we promise to finish this function
+ * for a caller. Here we use FCP_TIMEOUT_MS for next
+ * interval. This is not in the specification.
+ */
+ t.state = STATE_PENDING;
+ goto deferred;
+ } else if (t.state == STATE_COMPLETE) {
+ ret = t.response_size;
+ break;
+ } else if (t.state == STATE_BUS_RESET) {
+ msleep(ERROR_DELAY_MS);
+ } else if (++tries >= ERROR_RETRIES) {
+ dev_err(&t.unit->device, "FCP command timed out\n");
+ ret = -EIO;
+ break;
+ }
+ }
+
+ spin_lock_irq(&transactions_lock);
+ list_del(&t.list);
+ spin_unlock_irq(&transactions_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(fcp_avc_transaction);
+
+/**
+ * fcp_bus_reset - inform the target handler about a bus reset
+ * @unit: the unit that might be used by fcp_avc_transaction()
+ *
+ * This function must be called from the driver's .update handler to inform
+ * the FCP transaction handler that a bus reset has happened. Any pending FCP
+ * transactions are retried.
+ */
+void fcp_bus_reset(struct fw_unit *unit)
+{
+ struct fcp_transaction *t;
+
+ spin_lock_irq(&transactions_lock);
+ list_for_each_entry(t, &transactions, list) {
+ if (t->unit == unit &&
+ (t->state == STATE_PENDING ||
+ t->state == STATE_DEFERRED)) {
+ t->state = STATE_BUS_RESET;
+ wake_up(&t->wait);
+ }
+ }
+ spin_unlock_irq(&transactions_lock);
+}
+EXPORT_SYMBOL(fcp_bus_reset);
+
+/* checks whether the response matches the masked bytes in response_buffer */
+static bool is_matching_response(struct fcp_transaction *transaction,
+ const void *response, size_t length)
+{
+ const u8 *p1, *p2;
+ unsigned int mask, i;
+
+ p1 = response;
+ p2 = transaction->response_buffer;
+ mask = transaction->response_match_bytes;
+
+ for (i = 0; ; ++i) {
+ if ((mask & 1) && p1[i] != p2[i])
+ return false;
+ mask >>= 1;
+ if (!mask)
+ return true;
+ if (--length == 0)
+ return false;
+ }
+}
+
+static void fcp_response(struct fw_card *card, struct fw_request *request,
+ int tcode, int destination, int source,
+ int generation, unsigned long long offset,
+ void *data, size_t length, void *callback_data)
+{
+ struct fcp_transaction *t;
+ unsigned long flags;
+
+ if (length < 1 || (*(const u8 *)data & 0xf0) != CTS_AVC)
+ return;
+
+ spin_lock_irqsave(&transactions_lock, flags);
+ list_for_each_entry(t, &transactions, list) {
+ struct fw_device *device = fw_parent_device(t->unit);
+ if (device->card != card ||
+ device->generation != generation)
+ continue;
+ smp_rmb(); /* node_id vs. generation */
+ if (device->node_id != source)
+ continue;
+
+ if (t->state == STATE_PENDING &&
+ is_matching_response(t, data, length)) {
+ if (t->deferrable && *(const u8 *)data == 0x0f) {
+ t->state = STATE_DEFERRED;
+ } else {
+ t->state = STATE_COMPLETE;
+ t->response_size = min_t(unsigned int, length,
+ t->response_size);
+ memcpy(t->response_buffer, data,
+ t->response_size);
+ }
+ wake_up(&t->wait);
+ }
+ }
+ spin_unlock_irqrestore(&transactions_lock, flags);
+}
+
+static struct fw_address_handler response_register_handler = {
+ .length = 0x200,
+ .address_callback = fcp_response,
+};
+
+static int __init fcp_module_init(void)
+{
+ static const struct fw_address_region response_register_region = {
+ .start = CSR_REGISTER_BASE + CSR_FCP_RESPONSE,
+ .end = CSR_REGISTER_BASE + CSR_FCP_END,
+ };
+
+ fw_core_add_address_handler(&response_register_handler,
+ &response_register_region);
+
+ return 0;
+}
+
+static void __exit fcp_module_exit(void)
+{
+ WARN_ON(!list_empty(&transactions));
+ fw_core_remove_address_handler(&response_register_handler);
+}
+
+module_init(fcp_module_init);
+module_exit(fcp_module_exit);
Code Review / kvmfornfv.git / blobdiff