Initial import

1 files changed, 397 insertions, 0 deletions

diff --git a/sound/firewire/fcp.c b/sound/firewire/fcp.c
new file mode 100644
index 000000000..0619597e3
--- /dev/null
+++ b/sound/firewire/fcp.c
@@ -0,0 +1,397 @@
+/*
+ * 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);