/*
 * Copyright (c) 2004-2011 Atheros Communications Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "core.h"
#include "hif-ops.h"
#include "target.h"
#include "debug.h"

static int ath6kl_get_bmi_cmd_credits(struct ath6kl *ar)
{
	u32 addr;
	unsigned long timeout;
	int ret;

	ar->bmi.cmd_credits = 0;

	/* Read the counter register to get the command credits */
	addr = COUNT_DEC_ADDRESS + (HTC_MAILBOX_NUM_MAX + ENDPOINT1) * 4;

	timeout = jiffies + msecs_to_jiffies(BMI_COMMUNICATION_TIMEOUT);
	while (time_before(jiffies, timeout) && !ar->bmi.cmd_credits) {

		/*
		 * Hit the credit counter with a 4-byte access, the first byte
		 * read will hit the counter and cause a decrement, while the
		 * remaining 3 bytes has no effect. The rationale behind this
		 * is to make all HIF accesses 4-byte aligned.
		 */
		ret = hif_read_write_sync(ar, addr,
					 (u8 *)&ar->bmi.cmd_credits, 4,
					 HIF_RD_SYNC_BYTE_INC);
		if (ret) {
			ath6kl_err("Unable to decrement the command credit count register: %d\n",
				   ret);
			return ret;
		}

		/* The counter is only 8 bits.
		 * Ignore anything in the upper 3 bytes
		 */
		ar->bmi.cmd_credits &= 0xFF;
	}

	if (!ar->bmi.cmd_credits) {
		ath6kl_err("bmi communication timeout\n");
		return -ETIMEDOUT;
	}

	return 0;
}

static int ath6kl_bmi_get_rx_lkahd(struct ath6kl *ar)
{
	unsigned long timeout;
	u32 rx_word = 0;
	int ret = 0;

	timeout = jiffies + msecs_to_jiffies(BMI_COMMUNICATION_TIMEOUT);
	while (time_before(jiffies, timeout) && !rx_word) {
		ret = hif_read_write_sync(ar, RX_LOOKAHEAD_VALID_ADDRESS,
					  (u8 *)&rx_word, sizeof(rx_word),
					  HIF_RD_SYNC_BYTE_INC);
		if (ret) {
			ath6kl_err("unable to read RX_LOOKAHEAD_VALID\n");
			return ret;
		}

		 /* all we really want is one bit */
		rx_word &= (1 << ENDPOINT1);
	}

	if (!rx_word) {
		ath6kl_err("bmi_recv_buf FIFO empty\n");
		return -EINVAL;
	}

	return ret;
}

static int ath6kl_bmi_send_buf(struct ath6kl *ar, u8 *buf, u32 len)
{
	int ret;
	u32 addr;

	ret = ath6kl_get_bmi_cmd_credits(ar);
	if (ret)
		return ret;

	addr = ar->mbox_info.htc_addr;

	ret = hif_read_write_sync(ar, addr, buf, len,
				  HIF_WR_SYNC_BYTE_INC);
	if (ret)
		ath6kl_err("unable to send the bmi data to the device\n");

	return ret;
}

static int ath6kl_bmi_recv_buf(struct ath6kl *ar, u8 *buf, u32 len)
{
	int ret;
	u32 addr;

	/*
	 * During normal bootup, small reads may be required.
	 * Rather than issue an HIF Read and then wait as the Target
	 * adds successive bytes to the FIFO, we wait here until
	 * we know that response data is available.
	 *
	 * This allows us to cleanly timeout on an unexpected
	 * Target failure rather than risk problems at the HIF level.
	 * In particular, this avoids SDIO timeouts and possibly garbage
	 * data on some host controllers.  And on an interconnect
	 * such as Compact Flash (as well as some SDIO masters) which
	 * does not provide any indication on data timeout, it avoids
	 * a potential hang or garbage response.
	 *
	 * Synchronization is more difficult for reads larger than the
	 * size of the MBOX FIFO (128B), because the Target is unable
	 * to push the 129th byte of data until AFTER the Host posts an
	 * HIF Read and removes some FIFO data.  So for large reads the
	 * Host proceeds to post an HIF Read BEFORE all the data is
	 * actually available to read.  Fortunately, large BMI reads do
	 * not occur in practice -- they're supported for debug/development.
	 *
	 * So Host/Target BMI synchronization is divided into these cases:
	 *  CASE 1: length < 4
	 *        Should not happen
	 *
	 *  CASE 2: 4 <= length <= 128
	 *        Wait for first 4 bytes to be in FIFO
	 *        If CONSERVATIVE_BMI_READ is enabled, also wait for
	 *        a BMI command credit, which indicates that the ENTIRE
	 *        response is available in the the FIFO
	 *
	 *  CASE 3: length > 128
	 *        Wait for the first 4 bytes to be in FIFO
	 *
	 * For most uses, a small timeout should be sufficient and we will
	 * usually see a response quickly; but there may be some unusual
	 * (debug) cases of BMI_EXECUTE where we want an larger timeout.
	 * For now, we use an unbounded busy loop while waiting for
	 * BMI_EXECUTE.
	 *
	 * If BMI_EXECUTE ever needs to support longer-latency execution,
	 * especially in production, this code needs to be enhanced to sleep
	 * and yield.  Also note that BMI_COMMUNICATION_TIMEOUT is currently
	 * a function of Host processor speed.
	 */
	if (len >= 4) { /* NB: Currently, always true */
		ret = ath6kl_bmi_get_rx_lkahd(ar);
		if (ret)
			return ret;
	}

	addr = ar->mbox_info.htc_addr;
	ret = hif_read_write_sync(ar, addr, buf, len,
				  HIF_RD_SYNC_BYTE_INC);
	if (ret) {
		ath6kl_err("Unable to read the bmi data from the device: %d\n",
			   ret);
		return ret;
	}

	return 0;
}

int ath6kl_bmi_done(struct ath6kl *ar)
{
	int ret;
	u32 cid = BMI_DONE;

	if (ar->bmi.done_sent) {
		ath6kl_dbg(ATH6KL_DBG_BMI, "bmi done skipped\n");
		return 0;
	}

	ar->bmi.done_sent = true;

	ret = ath6kl_bmi_send_buf(ar, (u8 *)&cid, sizeof(cid));
	if (ret) {
		ath6kl_err("Unable to send bmi done: %d\n", ret);
		return ret;
	}

	ath6kl_bmi_cleanup(ar);

	return 0;
}

int ath6kl_bmi_get_target_info(struct ath6kl *ar,
			       struct ath6kl_bmi_target_info *targ_info)
{
	int ret;
	u32 cid = BMI_GET_TARGET_INFO;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	ret = ath6kl_bmi_send_buf(ar, (u8 *)&cid, sizeof(cid));
	if (ret) {
		ath6kl_err("Unable to send get target info: %d\n", ret);
		return ret;
	}

	ret = ath6kl_bmi_recv_buf(ar, (u8 *)&targ_info->version,
				  sizeof(targ_info->version));
	if (ret) {
		ath6kl_err("Unable to recv target info: %d\n", ret);
		return ret;
	}

	if (le32_to_cpu(targ_info->version) == TARGET_VERSION_SENTINAL) {
		/* Determine how many bytes are in the Target's targ_info */
		ret = ath6kl_bmi_recv_buf(ar,
				   (u8 *)&targ_info->byte_count,
				   sizeof(targ_info->byte_count));
		if (ret) {
			ath6kl_err("unable to read target info byte count: %d\n",
				   ret);
			return ret;
		}

		/*
		 * The target's targ_info doesn't match the host's targ_info.
		 * We need to do some backwards compatibility to make this work.
		 */
		if (le32_to_cpu(targ_info->byte_count) != sizeof(*targ_info)) {
			WARN_ON(1);
			return -EINVAL;
		}

		/* Read the remainder of the targ_info */
		ret = ath6kl_bmi_recv_buf(ar,
				   ((u8 *)targ_info) +
				   sizeof(targ_info->byte_count),
				   sizeof(*targ_info) -
				   sizeof(targ_info->byte_count));

		if (ret) {
			ath6kl_err("Unable to read target info (%d bytes): %d\n",
				   targ_info->byte_count, ret);
			return ret;
		}
	}

	ath6kl_dbg(ATH6KL_DBG_BMI, "target info (ver: 0x%x type: 0x%x)\n",
		targ_info->version, targ_info->type);

	return 0;
}

int ath6kl_bmi_read(struct ath6kl *ar, u32 addr, u8 *buf, u32 len)
{
	u32 cid = BMI_READ_MEMORY;
	int ret;
	u32 offset;
	u32 len_remain, rx_len;
	u16 size;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	size = BMI_DATASZ_MAX + sizeof(cid) + sizeof(addr) + sizeof(len);
	if (size > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}
	memset(ar->bmi.cmd_buf, 0, size);

	ath6kl_dbg(ATH6KL_DBG_BMI,
		   "bmi read memory: device: addr: 0x%x, len: %d\n",
		   addr, len);

	len_remain = len;

	while (len_remain) {
		rx_len = (len_remain < BMI_DATASZ_MAX) ?
					len_remain : BMI_DATASZ_MAX;
		offset = 0;
		memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
		offset += sizeof(cid);
		memcpy(&(ar->bmi.cmd_buf[offset]), &addr, sizeof(addr));
		offset += sizeof(addr);
		memcpy(&(ar->bmi.cmd_buf[offset]), &rx_len, sizeof(rx_len));
		offset += sizeof(len);

		ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
		if (ret) {
			ath6kl_err("Unable to write to the device: %d\n",
				   ret);
			return ret;
		}
		ret = ath6kl_bmi_recv_buf(ar, ar->bmi.cmd_buf, rx_len);
		if (ret) {
			ath6kl_err("Unable to read from the device: %d\n",
				   ret);
			return ret;
		}
		memcpy(&buf[len - len_remain], ar->bmi.cmd_buf, rx_len);
		len_remain -= rx_len; addr += rx_len;
	}

	return 0;
}

int ath6kl_bmi_write(struct ath6kl *ar, u32 addr, u8 *buf, u32 len)
{
	u32 cid = BMI_WRITE_MEMORY;
	int ret;
	u32 offset;
	u32 len_remain, tx_len;
	const u32 header = sizeof(cid) + sizeof(addr) + sizeof(len);
	u8 aligned_buf[BMI_DATASZ_MAX];
	u8 *src;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	if ((BMI_DATASZ_MAX + header) > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}

	memset(ar->bmi.cmd_buf, 0, BMI_DATASZ_MAX + header);

	ath6kl_dbg(ATH6KL_DBG_BMI,
		  "bmi write memory: addr: 0x%x, len: %d\n", addr, len);

	len_remain = len;
	while (len_remain) {
		src = &buf[len - len_remain];

		if (len_remain < (BMI_DATASZ_MAX - header)) {
			if (len_remain & 3) {
				/* align it with 4 bytes */
				len_remain = len_remain +
					     (4 - (len_remain & 3));
				memcpy(aligned_buf, src, len_remain);
				src = aligned_buf;
			}
			tx_len = len_remain;
		} else {
			tx_len = (BMI_DATASZ_MAX - header);
		}

		offset = 0;
		memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
		offset += sizeof(cid);
		memcpy(&(ar->bmi.cmd_buf[offset]), &addr, sizeof(addr));
		offset += sizeof(addr);
		memcpy(&(ar->bmi.cmd_buf[offset]), &tx_len, sizeof(tx_len));
		offset += sizeof(tx_len);
		memcpy(&(ar->bmi.cmd_buf[offset]), src, tx_len);
		offset += tx_len;

		ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
		if (ret) {
			ath6kl_err("Unable to write to the device: %d\n",
				   ret);
			return ret;
		}
		len_remain -= tx_len; addr += tx_len;
	}

	return 0;
}

int ath6kl_bmi_execute(struct ath6kl *ar, u32 addr, u32 *param)
{
	u32 cid = BMI_EXECUTE;
	int ret;
	u32 offset;
	u16 size;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	size = sizeof(cid) + sizeof(addr) + sizeof(param);
	if (size > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}
	memset(ar->bmi.cmd_buf, 0, size);

	ath6kl_dbg(ATH6KL_DBG_BMI, "bmi execute: addr: 0x%x, param: %d)\n",
		   addr, *param);

	offset = 0;
	memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
	offset += sizeof(cid);
	memcpy(&(ar->bmi.cmd_buf[offset]), &addr, sizeof(addr));
	offset += sizeof(addr);
	memcpy(&(ar->bmi.cmd_buf[offset]), param, sizeof(*param));
	offset += sizeof(*param);

	ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
	if (ret) {
		ath6kl_err("Unable to write to the device: %d\n", ret);
		return ret;
	}

	ret = ath6kl_bmi_recv_buf(ar, ar->bmi.cmd_buf, sizeof(*param));
	if (ret) {
		ath6kl_err("Unable to read from the device: %d\n", ret);
		return ret;
	}

	memcpy(param, ar->bmi.cmd_buf, sizeof(*param));

	return 0;
}

int ath6kl_bmi_set_app_start(struct ath6kl *ar, u32 addr)
{
	u32 cid = BMI_SET_APP_START;
	int ret;
	u32 offset;
	u16 size;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	size = sizeof(cid) + sizeof(addr);
	if (size > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}
	memset(ar->bmi.cmd_buf, 0, size);

	ath6kl_dbg(ATH6KL_DBG_BMI, "bmi set app start: addr: 0x%x\n", addr);

	offset = 0;
	memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
	offset += sizeof(cid);
	memcpy(&(ar->bmi.cmd_buf[offset]), &addr, sizeof(addr));
	offset += sizeof(addr);

	ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
	if (ret) {
		ath6kl_err("Unable to write to the device: %d\n", ret);
		return ret;
	}

	return 0;
}

int ath6kl_bmi_reg_read(struct ath6kl *ar, u32 addr, u32 *param)
{
	u32 cid = BMI_READ_SOC_REGISTER;
	int ret;
	u32 offset;
	u16 size;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	size = sizeof(cid) + sizeof(addr);
	if (size > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}
	memset(ar->bmi.cmd_buf, 0, size);

	ath6kl_dbg(ATH6KL_DBG_BMI, "bmi read SOC reg: addr: 0x%x\n", addr);

	offset = 0;
	memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
	offset += sizeof(cid);
	memcpy(&(ar->bmi.cmd_buf[offset]), &addr, sizeof(addr));
	offset += sizeof(addr);

	ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
	if (ret) {
		ath6kl_err("Unable to write to the device: %d\n", ret);
		return ret;
	}

	ret = ath6kl_bmi_recv_buf(ar, ar->bmi.cmd_buf, sizeof(*param));
	if (ret) {
		ath6kl_err("Unable to read from the device: %d\n", ret);
		return ret;
	}
	memcpy(param, ar->bmi.cmd_buf, sizeof(*param));

	return 0;
}

int ath6kl_bmi_reg_write(struct ath6kl *ar, u32 addr, u32 param)
{
	u32 cid = BMI_WRITE_SOC_REGISTER;
	int ret;
	u32 offset;
	u16 size;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	size = sizeof(cid) + sizeof(addr) + sizeof(param);
	if (size > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}
	memset(ar->bmi.cmd_buf, 0, size);

	ath6kl_dbg(ATH6KL_DBG_BMI,
		   "bmi write SOC reg: addr: 0x%x, param: %d\n",
		    addr, param);

	offset = 0;
	memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
	offset += sizeof(cid);
	memcpy(&(ar->bmi.cmd_buf[offset]), &addr, sizeof(addr));
	offset += sizeof(addr);
	memcpy(&(ar->bmi.cmd_buf[offset]), &param, sizeof(param));
	offset += sizeof(param);

	ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
	if (ret) {
		ath6kl_err("Unable to write to the device: %d\n", ret);
		return ret;
	}

	return 0;
}

int ath6kl_bmi_lz_data(struct ath6kl *ar, u8 *buf, u32 len)
{
	u32 cid = BMI_LZ_DATA;
	int ret;
	u32 offset;
	u32 len_remain, tx_len;
	const u32 header = sizeof(cid) + sizeof(len);
	u16 size;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	size = BMI_DATASZ_MAX + header;
	if (size > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}
	memset(ar->bmi.cmd_buf, 0, size);

	ath6kl_dbg(ATH6KL_DBG_BMI, "bmi send LZ data: len: %d)\n",
		   len);

	len_remain = len;
	while (len_remain) {
		tx_len = (len_remain < (BMI_DATASZ_MAX - header)) ?
			  len_remain : (BMI_DATASZ_MAX - header);

		offset = 0;
		memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
		offset += sizeof(cid);
		memcpy(&(ar->bmi.cmd_buf[offset]), &tx_len, sizeof(tx_len));
		offset += sizeof(tx_len);
		memcpy(&(ar->bmi.cmd_buf[offset]), &buf[len - len_remain],
			tx_len);
		offset += tx_len;

		ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
		if (ret) {
			ath6kl_err("Unable to write to the device: %d\n",
				   ret);
			return ret;
		}

		len_remain -= tx_len;
	}

	return 0;
}

int ath6kl_bmi_lz_stream_start(struct ath6kl *ar, u32 addr)
{
	u32 cid = BMI_LZ_STREAM_START;
	int ret;
	u32 offset;
	u16 size;

	if (ar->bmi.done_sent) {
		ath6kl_err("bmi done sent already, cmd %d disallowed\n", cid);
		return -EACCES;
	}

	size = sizeof(cid) + sizeof(addr);
	if (size > MAX_BMI_CMDBUF_SZ) {
		WARN_ON(1);
		return -EINVAL;
	}
	memset(ar->bmi.cmd_buf, 0, size);

	ath6kl_dbg(ATH6KL_DBG_BMI,
		   "bmi LZ stream start: addr: 0x%x)\n",
		    addr);

	offset = 0;
	memcpy(&(ar->bmi.cmd_buf[offset]), &cid, sizeof(cid));
	offset += sizeof(cid);
	memcpy(&(ar->bmi.cmd_buf[offset]), &addr, sizeof(addr));
	offset += sizeof(addr);

	ret = ath6kl_bmi_send_buf(ar, ar->bmi.cmd_buf, offset);
	if (ret) {
		ath6kl_err("Unable to start LZ stream to the device: %d\n",
			   ret);
		return ret;
	}

	return 0;
}

int ath6kl_bmi_fast_download(struct ath6kl *ar, u32 addr, u8 *buf, u32 len)
{
	int ret;
	u32 last_word = 0;
	u32 last_word_offset = len & ~0x3;
	u32 unaligned_bytes = len & 0x3;

	ret = ath6kl_bmi_lz_stream_start(ar, addr);
	if (ret)
		return ret;

	if (unaligned_bytes) {
		/* copy the last word into a zero padded buffer */
		memcpy(&last_word, &buf[last_word_offset], unaligned_bytes);
	}

	ret = ath6kl_bmi_lz_data(ar, buf, last_word_offset);
	if (ret)
		return ret;

	if (unaligned_bytes)
		ret = ath6kl_bmi_lz_data(ar, (u8 *)&last_word, 4);

	if (!ret) {
		/* Close compressed stream and open a new (fake) one.
		 * This serves mainly to flush Target caches. */
		ret = ath6kl_bmi_lz_stream_start(ar, 0x00);
	}
	return ret;
}

int ath6kl_bmi_init(struct ath6kl *ar)
{
	ar->bmi.cmd_buf = kzalloc(MAX_BMI_CMDBUF_SZ, GFP_ATOMIC);

	if (!ar->bmi.cmd_buf)
		return -ENOMEM;

	return 0;
}

void ath6kl_bmi_cleanup(struct ath6kl *ar)
{
	kfree(ar->bmi.cmd_buf);
	ar->bmi.cmd_buf = NULL;
}