/*-
*******************************************************************************
Copyright (C) 2015 Annapurna Labs Ltd.

This file may be licensed under the terms of the Annapurna Labs Commercial
License Agreement.

Alternatively, this file can be distributed under the terms of the GNU General
Public License V2 as published by the Free Software Foundation and can be
found at http://www.gnu.org/licenses/gpl-2.0.html

Alternatively, redistribution and use in source and binary forms, with or
without modification, are permitted provided that the following conditions are
met:

    *     Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.

    *     Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*******************************************************************************/

/**
 *  @{
 * @file   al_hal_udma_main.c
 *
 * @brief  Universal DMA HAL driver for main functions (initialization, data path)
 *
 */

#include <al_hal_udma.h>
#include <al_hal_udma_config.h>

#define AL_UDMA_Q_RST_TOUT	10000	/* Queue reset timeout [uSecs] */

#define UDMA_STATE_IDLE		0x0
#define UDMA_STATE_NORMAL	0x1
#define UDMA_STATE_ABORT	0x2
#define UDMA_STATE_RESERVED	0x3

const char *const al_udma_states_name[] = {
	"Disable",
	"Idle",
	"Normal",
	"Abort",
	"Reset"
};

#define AL_UDMA_INITIAL_RING_ID	1

/*  dma_q flags */
#define AL_UDMA_Q_FLAGS_IGNORE_RING_ID	AL_BIT(0)
#define AL_UDMA_Q_FLAGS_NO_COMP_UPDATE	AL_BIT(1)
#define AL_UDMA_Q_FLAGS_EN_COMP_COAL	AL_BIT(2)


static void al_udma_set_defaults(struct al_udma *udma)
{
	uint8_t rev_id = udma->rev_id;

	if (udma->type == UDMA_TX) {
		struct unit_regs* tmp_unit_regs =
			(struct unit_regs*)udma->udma_regs;

		/* Setting the data fifo depth to 4K (256 strips of 16B)
		 * This allows the UDMA to have 16 outstanding writes */
		if (rev_id >= AL_UDMA_REV_ID_2) {
			al_reg_write32_masked(&tmp_unit_regs->m2s.m2s_rd.data_cfg,
			      UDMA_M2S_RD_DATA_CFG_DATA_FIFO_DEPTH_MASK,
			      256 << UDMA_M2S_RD_DATA_CFG_DATA_FIFO_DEPTH_SHIFT);
		}

		/* set AXI timeout to 1M (~2.6 ms) */
		al_reg_write32(&tmp_unit_regs->gen.axi.cfg_1, 1000000);

		al_reg_write32(&tmp_unit_regs->m2s.m2s_comp.cfg_application_ack
					, 0); /* Ack time out */
	}
	if (udma->type == UDMA_RX) {
		al_reg_write32(
			&udma->udma_regs->s2m.s2m_comp.cfg_application_ack, 0);
					/* Ack time out */

	}
}
/**
 * misc queue configurations
 *
 * @param udma_q udma queue data structure
 *
 * @return 0
 */
static int al_udma_q_config(struct al_udma_q *udma_q)
{
	uint32_t *reg_addr;
	uint32_t val;

	if (udma_q->udma->type == UDMA_TX) {
		reg_addr = &udma_q->q_regs->m2s_q.rlimit.mask;

		val = al_reg_read32(reg_addr);
		// enable DMB
		val &= ~UDMA_M2S_Q_RATE_LIMIT_MASK_INTERNAL_PAUSE_DMB;
		al_reg_write32(reg_addr, val);
	}
	return 0;
}

/**
 * set the queue's completion configuration register
 *
 * @param udma_q udma queue data structure
 *
 * @return 0
 */
static int al_udma_q_config_compl(struct al_udma_q *udma_q)
{
	uint32_t *reg_addr;
	uint32_t val;

	if (udma_q->udma->type == UDMA_TX)
		reg_addr = &udma_q->q_regs->m2s_q.comp_cfg;
	else
		reg_addr = &udma_q->q_regs->s2m_q.comp_cfg;

	val = al_reg_read32(reg_addr);

	if (udma_q->flags & AL_UDMA_Q_FLAGS_NO_COMP_UPDATE)
		val &= ~UDMA_M2S_Q_COMP_CFG_EN_COMP_RING_UPDATE;
	else
		val |= UDMA_M2S_Q_COMP_CFG_EN_COMP_RING_UPDATE;

	if (udma_q->flags & AL_UDMA_Q_FLAGS_EN_COMP_COAL)
		val &= ~UDMA_M2S_Q_COMP_CFG_DIS_COMP_COAL;
	else
		val |= UDMA_M2S_Q_COMP_CFG_DIS_COMP_COAL;

	al_reg_write32(reg_addr, val);

	/* set the completion queue size */
	if (udma_q->udma->type == UDMA_RX) {
		val = al_reg_read32(
				&udma_q->udma->udma_regs->s2m.s2m_comp.cfg_1c);
		val &= ~UDMA_S2M_COMP_CFG_1C_DESC_SIZE_MASK;
		/* the register expects it to be in words */
		val |= (udma_q->cdesc_size >> 2)
				& UDMA_S2M_COMP_CFG_1C_DESC_SIZE_MASK;
		al_reg_write32(&udma_q->udma->udma_regs->s2m.s2m_comp.cfg_1c
							, val);
	}
	return 0;
}

/**
 * reset the queues pointers (Head, Tail, etc) and set the base addresses
 *
 * @param udma_q udma queue data structure
 */
static int al_udma_q_set_pointers(struct al_udma_q *udma_q)
{
	/* reset the descriptors ring pointers */
	/* assert descriptor base address aligned. */
	al_assert((AL_ADDR_LOW(udma_q->desc_phy_base) &
		   ~UDMA_M2S_Q_TDRBP_LOW_ADDR_MASK) == 0);
	al_reg_write32(&udma_q->q_regs->rings.drbp_low,
		       AL_ADDR_LOW(udma_q->desc_phy_base));
	al_reg_write32(&udma_q->q_regs->rings.drbp_high,
		       AL_ADDR_HIGH(udma_q->desc_phy_base));

	al_reg_write32(&udma_q->q_regs->rings.drl, udma_q->size);

	/* if completion ring update disabled */
	if (udma_q->cdesc_base_ptr == NULL) {
		udma_q->flags |= AL_UDMA_Q_FLAGS_NO_COMP_UPDATE;
	} else {
		/* reset the completion descriptors ring pointers */
		/* assert completion base address aligned. */
		al_assert((AL_ADDR_LOW(udma_q->cdesc_phy_base) &
			   ~UDMA_M2S_Q_TCRBP_LOW_ADDR_MASK) == 0);
		al_reg_write32(&udma_q->q_regs->rings.crbp_low,
			       AL_ADDR_LOW(udma_q->cdesc_phy_base));
		al_reg_write32(&udma_q->q_regs->rings.crbp_high,
			       AL_ADDR_HIGH(udma_q->cdesc_phy_base));
	}
	al_udma_q_config_compl(udma_q);
	return 0;
}

/**
 * enable/disable udma queue
 *
 * @param udma_q udma queue data structure
 * @param enable none zero value enables the queue, zero means disable
 *
 * @return 0
 */
static int al_udma_q_enable(struct al_udma_q *udma_q, int enable)
{
	uint32_t reg = al_reg_read32(&udma_q->q_regs->rings.cfg);

	if (enable) {
		reg |= (UDMA_M2S_Q_CFG_EN_PREF | UDMA_M2S_Q_CFG_EN_SCHEDULING);
		udma_q->status = AL_QUEUE_ENABLED;
	} else {
		reg &= ~(UDMA_M2S_Q_CFG_EN_PREF | UDMA_M2S_Q_CFG_EN_SCHEDULING);
		udma_q->status = AL_QUEUE_DISABLED;
	}
	al_reg_write32(&udma_q->q_regs->rings.cfg, reg);
	return 0;
}


/************************ API functions ***************************************/

/* Initializations functions */
/*
 * Initialize the udma engine
 */
int al_udma_init(struct al_udma *udma, struct al_udma_params *udma_params)
{
	int i;

	al_assert(udma);

	if (udma_params->num_of_queues > DMA_MAX_Q) {
		al_err("udma: invalid num_of_queues parameter\n");
		return -EINVAL;
	}

	udma->type = udma_params->type;
	udma->num_of_queues = udma_params->num_of_queues;
	udma->gen_regs = &udma_params->udma_regs_base->gen;

	if (udma->type == UDMA_TX)
		udma->udma_regs = (union udma_regs *)&udma_params->udma_regs_base->m2s;
	else
		udma->udma_regs = (union udma_regs *)&udma_params->udma_regs_base->s2m;

	udma->rev_id = al_udma_get_revision(udma_params->udma_regs_base);

	if (udma_params->name == NULL)
		udma->name = "";
	else
		udma->name = udma_params->name;

	udma->state = UDMA_DISABLE;
	for (i = 0; i < DMA_MAX_Q; i++) {
		udma->udma_q[i].status = AL_QUEUE_NOT_INITIALIZED;
	}
	/* initialize configuration registers to correct values */
	al_udma_set_defaults(udma);
	al_dbg("udma [%s] initialized. base %p\n", udma->name,
		udma->udma_regs);
	return 0;
}

/*
 * Initialize the udma queue data structure
 */
int al_udma_q_init(struct al_udma *udma, uint32_t qid,
					struct al_udma_q_params *q_params)
{
	struct al_udma_q *udma_q;

	al_assert(udma);
	al_assert(q_params);

	if (qid >= udma->num_of_queues) {
		al_err("udma: invalid queue id (%d)\n", qid);
		return -EINVAL;
	}

	if (udma->udma_q[qid].status == AL_QUEUE_ENABLED) {
		al_err("udma: queue (%d) already enabled!\n", qid);
		return -EIO;
	}

	if (q_params->size < AL_UDMA_MIN_Q_SIZE) {
		al_err("udma: queue (%d) size too small\n", qid);
		return -EINVAL;
	}

	if (q_params->size > AL_UDMA_MAX_Q_SIZE) {
		al_err("udma: queue (%d) size too large\n", qid);
		return -EINVAL;
	}

	if (q_params->size & (q_params->size - 1)) {
		al_err("udma: queue (%d) size (%d) must be power of 2\n",
			 q_params->size, qid);
		return -EINVAL;
	}

	udma_q = &udma->udma_q[qid];
	/* set the queue's regs base address */
	if (udma->type == UDMA_TX)
		udma_q->q_regs = (union udma_q_regs __iomem *)
					&udma->udma_regs->m2s.m2s_q[qid];
	else
		udma_q->q_regs = (union udma_q_regs __iomem *)
					&udma->udma_regs->s2m.s2m_q[qid];

	udma_q->adapter_rev_id = q_params->adapter_rev_id;
	udma_q->size = q_params->size;
	udma_q->size_mask = q_params->size - 1;
	udma_q->desc_base_ptr = q_params->desc_base;
	udma_q->desc_phy_base = q_params->desc_phy_base;
	udma_q->cdesc_base_ptr = q_params->cdesc_base;
	udma_q->cdesc_phy_base = q_params->cdesc_phy_base;
	udma_q->cdesc_size = q_params->cdesc_size;

	udma_q->next_desc_idx = 0;
	udma_q->next_cdesc_idx = 0;
	udma_q->end_cdesc_ptr = (uint8_t *) udma_q->cdesc_base_ptr +
	    (udma_q->size - 1) * udma_q->cdesc_size;
	udma_q->comp_head_idx = 0;
	udma_q->comp_head_ptr = (union al_udma_cdesc *)udma_q->cdesc_base_ptr;
	udma_q->desc_ring_id = AL_UDMA_INITIAL_RING_ID;
	udma_q->comp_ring_id = AL_UDMA_INITIAL_RING_ID;
#if 0
	udma_q->desc_ctrl_bits = AL_UDMA_INITIAL_RING_ID <<
						AL_M2S_DESC_RING_ID_SHIFT;
#endif
	udma_q->pkt_crnt_descs = 0;
	udma_q->flags = 0;
	udma_q->status = AL_QUEUE_DISABLED;
	udma_q->udma = udma;
	udma_q->qid = qid;

	/* start hardware configuration: */
	al_udma_q_config(udma_q);
	/* reset the queue pointers */
	al_udma_q_set_pointers(udma_q);

	/* enable the q */
	al_udma_q_enable(udma_q, 1);

	al_dbg("udma [%s %d]: %s q init. size 0x%x\n"
			"  desc ring info: phys base 0x%llx virt base %p)",
			udma_q->udma->name, udma_q->qid,
			udma->type == UDMA_TX ? "Tx" : "Rx",
			q_params->size,
			(unsigned long long)q_params->desc_phy_base,
			q_params->desc_base);
	al_dbg("  cdesc ring info: phys base 0x%llx virt base %p entry size 0x%x",
			(unsigned long long)q_params->cdesc_phy_base,
			q_params->cdesc_base,
			q_params->cdesc_size);

	return 0;
}

/*
 * Reset a udma queue
 */
int al_udma_q_reset(struct al_udma_q *udma_q)
{
	unsigned int remaining_time = AL_UDMA_Q_RST_TOUT;
	uint32_t *status_reg;
	uint32_t *dcp_reg;
	uint32_t *crhp_reg;
	uint32_t *q_sw_ctrl_reg;

	al_assert(udma_q);

	/* De-assert scheduling and prefetch */
	al_udma_q_enable(udma_q, 0);

	/* Wait for scheduling and prefetch to stop */
	status_reg = &udma_q->q_regs->rings.status;

	while (remaining_time) {
		uint32_t status = al_reg_read32(status_reg);

		if (!(status & (UDMA_M2S_Q_STATUS_PREFETCH |
						UDMA_M2S_Q_STATUS_SCHEDULER)))
			break;

		remaining_time--;
		al_udelay(1);
	}

	if (!remaining_time) {
		al_err("udma [%s %d]: %s timeout waiting for prefetch and "
			"scheduler disable\n", udma_q->udma->name, udma_q->qid,
			__func__);
		return -ETIMEDOUT;
	}

	/* Wait for the completion queue to reach to the same pointer as the
	 * prefetch stopped at ([TR]DCP == [TR]CRHP) */
	dcp_reg = &udma_q->q_regs->rings.dcp;
	crhp_reg = &udma_q->q_regs->rings.crhp;

	while (remaining_time) {
		uint32_t dcp = al_reg_read32(dcp_reg);
		uint32_t crhp = al_reg_read32(crhp_reg);

		if (dcp == crhp)
			break;

		remaining_time--;
		al_udelay(1);
	};

	if (!remaining_time) {
		al_err("udma [%s %d]: %s timeout waiting for dcp==crhp\n",
			udma_q->udma->name, udma_q->qid, __func__);
		return -ETIMEDOUT;
	}

	/* Assert the queue reset */
	if (udma_q->udma->type == UDMA_TX)
		q_sw_ctrl_reg = &udma_q->q_regs->m2s_q.q_sw_ctrl;
	else
		q_sw_ctrl_reg = &udma_q->q_regs->s2m_q.q_sw_ctrl;

	al_reg_write32(q_sw_ctrl_reg, UDMA_M2S_Q_SW_CTRL_RST_Q);

	return 0;
}

/*
 * return (by reference) a pointer to a specific queue date structure.
 */
int al_udma_q_handle_get(struct al_udma *udma, uint32_t qid,
						struct al_udma_q **q_handle)
{

	al_assert(udma);
	al_assert(q_handle);

	if (unlikely(qid >= udma->num_of_queues)) {
		al_err("udma [%s]: invalid queue id (%d)\n", udma->name, qid);
		return -EINVAL;
	}
	*q_handle = &udma->udma_q[qid];
	return 0;
}

/*
 * Change the UDMA's state
 */
int al_udma_state_set(struct al_udma *udma, enum al_udma_state state)
{
	uint32_t reg;

	al_assert(udma != NULL);
	if (state == udma->state)
		al_dbg("udma [%s]: requested state identical to "
			"current state (%d)\n", udma->name, state);

	al_dbg("udma [%s]: change state from (%s) to (%s)\n",
		 udma->name, al_udma_states_name[udma->state],
		 al_udma_states_name[state]);

	reg = 0;
	switch (state) {
	case UDMA_DISABLE:
		reg |= UDMA_M2S_CHANGE_STATE_DIS;
		break;
	case UDMA_NORMAL:
		reg |= UDMA_M2S_CHANGE_STATE_NORMAL;
		break;
	case UDMA_ABORT:
		reg |= UDMA_M2S_CHANGE_STATE_ABORT;
		break;
	default:
		al_err("udma: invalid state (%d)\n", state);
		return -EINVAL;
	}

	if (udma->type == UDMA_TX)
		al_reg_write32(&udma->udma_regs->m2s.m2s.change_state, reg);
	else
		al_reg_write32(&udma->udma_regs->s2m.s2m.change_state, reg);

	udma->state = state;
	return 0;
}

/*
 * return the current UDMA hardware state
 */
enum al_udma_state al_udma_state_get(struct al_udma *udma)
{
	uint32_t state_reg;
	uint32_t comp_ctrl;
	uint32_t stream_if;
	uint32_t data_rd;
	uint32_t desc_pref;

	if (udma->type == UDMA_TX)
		state_reg = al_reg_read32(&udma->udma_regs->m2s.m2s.state);
	else
		state_reg = al_reg_read32(&udma->udma_regs->s2m.s2m.state);

	comp_ctrl = AL_REG_FIELD_GET(state_reg,
				     UDMA_M2S_STATE_COMP_CTRL_MASK,
				     UDMA_M2S_STATE_COMP_CTRL_SHIFT);
	stream_if = AL_REG_FIELD_GET(state_reg,
				     UDMA_M2S_STATE_STREAM_IF_MASK,
				     UDMA_M2S_STATE_STREAM_IF_SHIFT);
	data_rd = AL_REG_FIELD_GET(state_reg,
				   UDMA_M2S_STATE_DATA_RD_CTRL_MASK,
				   UDMA_M2S_STATE_DATA_RD_CTRL_SHIFT);
	desc_pref = AL_REG_FIELD_GET(state_reg,
				     UDMA_M2S_STATE_DESC_PREF_MASK,
				     UDMA_M2S_STATE_DESC_PREF_SHIFT);

	al_assert(comp_ctrl != UDMA_STATE_RESERVED);
	al_assert(stream_if != UDMA_STATE_RESERVED);
	al_assert(data_rd != UDMA_STATE_RESERVED);
	al_assert(desc_pref != UDMA_STATE_RESERVED);

	/* if any of the states is abort then return abort */
	if ((comp_ctrl == UDMA_STATE_ABORT) || (stream_if == UDMA_STATE_ABORT)
			|| (data_rd == UDMA_STATE_ABORT)
			|| (desc_pref == UDMA_STATE_ABORT))
		return UDMA_ABORT;

	/* if any of the states is normal then return normal */
	if ((comp_ctrl == UDMA_STATE_NORMAL)
			|| (stream_if == UDMA_STATE_NORMAL)
			|| (data_rd == UDMA_STATE_NORMAL)
			|| (desc_pref == UDMA_STATE_NORMAL))
		return UDMA_NORMAL;

	return UDMA_IDLE;
}

/*
 * Action handling
 */

/*
 * get next completed packet from completion ring of the queue
 */
uint32_t al_udma_cdesc_packet_get(
	struct al_udma_q		*udma_q,
	volatile union al_udma_cdesc	**cdesc)
{
	uint32_t count;
	volatile union al_udma_cdesc *curr;
	uint32_t comp_flags;

	/* this function requires the completion ring update */
	al_assert(!(udma_q->flags & AL_UDMA_Q_FLAGS_NO_COMP_UPDATE));

	/* comp_head points to the last comp desc that was processed */
	curr = udma_q->comp_head_ptr;
	comp_flags = swap32_from_le(curr->al_desc_comp_tx.ctrl_meta);

	/* check if the completion descriptor is new */
	if (unlikely(al_udma_new_cdesc(udma_q, comp_flags) == AL_FALSE))
		return 0;
	/* if new desc found, increment the current packets descriptors */
	count = udma_q->pkt_crnt_descs + 1;
	while (!cdesc_is_last(comp_flags)) {
		curr = al_cdesc_next_update(udma_q, curr);
		comp_flags = swap32_from_le(curr->al_desc_comp_tx.ctrl_meta);
		if (unlikely(al_udma_new_cdesc(udma_q, comp_flags)
								== AL_FALSE)) {
			/* the current packet here doesn't have all  */
			/* descriptors completed. log the current desc */
			/* location and number of completed descriptors so */
			/*  far. then return */
			udma_q->pkt_crnt_descs = count;
			udma_q->comp_head_ptr = curr;
			return 0;
		}
		count++;
		/* check against max descs per packet. */
		al_assert(count <= udma_q->size);
	}
	/* return back the first descriptor of the packet */
	*cdesc = al_udma_cdesc_idx_to_ptr(udma_q, udma_q->next_cdesc_idx);
	udma_q->pkt_crnt_descs = 0;
	udma_q->comp_head_ptr = al_cdesc_next_update(udma_q, curr);

	al_dbg("udma [%s %d]: packet completed. first desc %p (ixd 0x%x)"
		 " descs %d\n", udma_q->udma->name, udma_q->qid, *cdesc,
		 udma_q->next_cdesc_idx, count);

	return count;
}

/** @} end of UDMA group */