drivers/dma/bam.c

/* Copyright (c) 2012,2015-2018 The Linux Foundation. All rights reserved.
 *
 * 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.
 *     * Neither the name of The Linux Foundation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * 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.
 */

#include <asm/io.h>
#include <asm/errno.h>

#include <common.h>
#include <asm/arch-qca-common/bam.h>
#define HLOS_EE_INDEX          0
#define TIMEOUT		2000

/* Resets pipe registers and state machines */
void bam_pipe_reset(struct bam_instance *bam,
					uint8_t pipe_num)
{
	/* Start sw reset of the pipe to be allocated */
	writel(1, BAM_P_RSTn(bam->pipe[pipe_num].pipe_num, bam->base));

	/* No delay required */

	/* Stop sw reset of the pipe to be allocated */
	writel(0, BAM_P_RSTn(bam->pipe[pipe_num].pipe_num, bam->base));
}

/* A blocking function that waits till an interrupt is signalled.
 * bam : BAM instance for the descriptors to be queued.
 * pipe_num : pipe number for the descriptors to be queued.
 * interrupt: interrupt to wait for.
 */
int bam_wait_for_interrupt(struct bam_instance *bam,
                           uint8_t pipe_num,
                           enum p_int_type interrupt)
{
	uint32_t val;
	uint32_t start;

	while (1)
	{
		start = get_timer(0);
		/* Wait for a interrupt on the right pipe */
		do{
			/* Determine the pipe causing the interrupt */
			val = readl(BAM_IRQ_SRCS(bam->base, bam->ee));
			if(get_timer(start) >= TIMEOUT)
				return BAM_RESULT_FAILURE;
			/* Flush out the right most global interrupt bit */
		} while (!((val & BAM_IRQ_SRCS_PIPE_MASK) &
				   (1 << bam->pipe[pipe_num].pipe_num)));

		/* Check the interrupt type */
		/* Read interrupt status register */
		val = readl(BAM_P_IRQ_STTSn(bam->pipe[pipe_num].pipe_num, bam->base));

		/* Check for error */
		if (val & P_ERR_EN_MASK)
			goto bam_wait_int_error;

		if (val & interrupt)
		{
			/* Correct interrupt was fired. */
			 /* Clear the other interrupts */
			val = P_OUT_OF_DESC_EN_MASK | P_PRCSD_DESC_EN_MASK | P_TRNSFR_END_EN_MASK;
			writel (val, BAM_P_IRQ_CLRn(bam->pipe[pipe_num].pipe_num, bam->base));
			return BAM_RESULT_SUCCESS;
		}
	}

bam_wait_int_error:

	printf("bam: Unexpected interrupt : val %u\n", val);
	return BAM_RESULT_FAILURE;
}

/* Enable BAM and pipe level interrupts */
void bam_enable_interrupts(struct bam_instance *bam, uint8_t pipe_num)
{

	uint32_t int_mask = P_ERR_EN_MASK | P_OUT_OF_DESC_EN_MASK |
						P_PRCSD_DESC_EN_MASK;
	uint32_t val;

	/* Leave BAM error interrupts disabled. */
	/* Enable the interrupts for the pipe by enabling the relevant bits
	 * in the BAM_PIPE_INTERRUPT_ENABLE register.
	 */
	writel(int_mask,
			BAM_P_IRQ_ENn(bam->pipe[pipe_num].pipe_num, bam->base));
	/* Enable pipe interrups */
	/* Do read-modify-write */
	val = readl(BAM_IRQ_SRCS_MSK(bam->base, bam->ee));
	writel((1 << bam->pipe[pipe_num].pipe_num) | val,
			BAM_IRQ_SRCS_MSK(bam->base, bam->ee));
}

/* Reset and initialize the bam module */
void bam_init(struct bam_instance *bam)
{
	uint32_t val = 0;

	/* Check for only one pipe's direction.
	 * The other is assumed to be the opposite system
	 * transaction.
	 */
	if (bam->pipe[0].trans_type == SYS2BAM ||
		bam->pipe[0].trans_type == BAM2SYS)
	{
		/* Program the threshold count */
		writel(bam->threshold, BAM_DESC_CNT_TRSHLD_REG(bam->base));
	}

	/* Program config register for H/W bug fixes */
	val = 0xffffffff & ~(1 << 11);
	writel(val, BAM_CNFG_BITS(bam->base));

	val = readl(BAM_CTRL_REG(bam->base));
	val = val | BAM_ENABLE_BIT_MASK;
	/* Enable the BAM */
	writel(val, BAM_CTRL_REG(bam->base));
}

/* Funtion to setup a simple fifo structure.
 * Note: Addr should be 8 byte aligned.
 * bam : BAM instance for the descriptors to be queued.
 * pipe_num : pipe number for the descriptors to be queued.
 */
int bam_pipe_fifo_init(struct bam_instance *bam,
                       uint8_t pipe_num)
{
	if (bam->pipe[pipe_num].fifo.size > 0x7FFF) {
		printf("bam: Size exceeds max size for a descriptor(0x7FFF)\n");
		return BAM_RESULT_FAILURE;
	}

	/* Check if fifo start is 8-byte alligned */
	if ((addr_t)bam->pipe[pipe_num].fifo.head & 0x7) {
		return BAM_RESULT_FAILURE;
	}

	/* Check if fifo size is a power of 2.
	 * The circular fifo logic in lk expects this.
	 */

	if (!(ispow2(bam->pipe[pipe_num].fifo.size))) {
		return BAM_RESULT_FAILURE;
	}

	bam->pipe[pipe_num].fifo.current = bam->pipe[pipe_num].fifo.head;

	/* Set the descriptor buffer size. Must be a multiple of 8 */
	writel(bam->pipe[pipe_num].fifo.size * BAM_DESC_SIZE,
		BAM_P_FIFO_SIZESn(bam->pipe[pipe_num].pipe_num, bam->base));

	/* Write descriptors FIFO base addr must be 8-byte aligned */
	/* Needs a physical address conversion as we are setting up
	 * the base of the FIFO for the BAM state machine.
	 */
	writel((uint32_t)((addr_t)bam->pipe[pipe_num].fifo.head),
		BAM_P_DESC_FIFO_ADDRn(bam->pipe[pipe_num].pipe_num, bam->base));

	/* Initialize FIFO offset for the first read */
	bam->pipe[pipe_num].fifo.offset = BAM_DESC_SIZE;

	writel(P_ENABLE | readl(BAM_P_CTRLn(bam->pipe[pipe_num].pipe_num, bam->base)),
		   BAM_P_CTRLn(bam->pipe[pipe_num].pipe_num, bam->base));

	/* Everything is set.
	 * Flag pipe init done.
	 */
	 bam->pipe[pipe_num].initialized = 1;

	return BAM_RESULT_SUCCESS;
}

void bam_sys_pipe_init(struct bam_instance *bam,
                       uint8_t pipe_num)
{
	/* Reset the pipe to be allocated */
	bam_pipe_reset(bam, pipe_num);

	/* Enable minimal interrupts */
	bam_enable_interrupts(bam, pipe_num);
	/* Pipe event threshold register is not relevant in sys modes */

	/* Enable pipe in system mode and set the direction */
	writel(P_SYS_MODE_MASK | bam->pipe[pipe_num].lock_grp <<  P_LOCK_GRP_SHIFT |
		   (bam->pipe[pipe_num].trans_type << P_DIRECTION_SHIFT),
		   BAM_P_CTRLn(bam->pipe[pipe_num].pipe_num, bam->base));

	/* Mark the pipe FIFO as uninitialized. */
	bam->pipe[pipe_num].initialized = 0;
}

/* Function to notify written descriptors to BAM.
 * bam : BAM instance for the descriptors to be queued.
 * pipe_num : pipe number for the descriptors to be queued.
 * num_desc : number of the descriptors.
 * fifo : Circular FIFO used for the descriptors.
 */
void bam_sys_gen_event(struct bam_instance *bam,
                       uint8_t pipe_num,
                       unsigned int num_desc)
{
	uint32_t val = 0;

	if (num_desc >= bam->pipe[pipe_num].fifo.size) {
		printf("bam: Max allowed desc is one less than the fifo length\n");
		return;
	}

	/* bits 0:15 of BAM_P_EVNT_REGn denotes the offset. We read the offset,
	 * and update the offset to notify BAM HW that new descriptors have been written
	 */
	val = readl(BAM_P_EVNT_REGn(bam->pipe[pipe_num].pipe_num, bam->base));

	/* Update the fifo peer offset */
	val += (num_desc) * BAM_DESC_SIZE;
	val &= (bam->pipe[pipe_num].fifo.size * BAM_DESC_SIZE - 1);

	writel(val, BAM_P_EVNT_REGn(bam->pipe[pipe_num].pipe_num, bam->base));
}

/* Function to read the updates for FIFO offsets.
 * bam : BAM that uses the FIFO.
 * pipe : BAM pipe that uses the FIFO.
 * return : void.
 * Note : As per IPCAT This register denotes the pointer Offset of the first un-Acknowledged Descriptor.
 *        This register is only used by the Software. After receiving an interrupt, software reads this register
 *        in order to know what descriptors has been processed. Although being Writable, Software
 *        should never write to this register.
 */
void bam_read_offset_update(struct bam_instance *bam, unsigned int pipe_num)
{
	uint32_t offset;

	offset = readl(BAM_P_SW_OFSTSn(bam->pipe[pipe_num].pipe_num, bam->base));
	offset &= 0xFFFF;
}

/* Function to get the next desc address.
 * Keeps track of circular properties of the FIFO
 * and returns the appropriate address.
 */
static struct bam_desc* fifo_getnext(struct bam_desc_fifo *fifo,
                                     struct bam_desc* desc)
{
	uint16_t offset;

	offset = desc - fifo->head;

	if (offset == (fifo->size - 1))
		return fifo->head;
	else
		return desc + 1;
}

/* Function to add BAM descriptors for a given fifo.
 * bam : BAM instance to be used.
 * data_ptr : Memory address for data transfer.
 * data_len : Length of the data_ptr.
 * flags : Flags to be set on the last desc added.
 *
 * Note: This function also notifies the BAM about the added descriptors.
 */
int bam_add_desc(struct bam_instance *bam,
                 unsigned int pipe_num,
                 unsigned char *data_ptr,
                 unsigned int data_len,
                 unsigned flags)
{
	int bam_ret = BAM_RESULT_SUCCESS;
	unsigned int len = data_len;
	unsigned int desc_len;
	unsigned int n = 0;
	unsigned int desc_flags;

	if (data_ptr == NULL || len == 0) {
		printf("bam: Wrong params for BAM transfer \n");
		bam_ret = BAM_RESULT_FAILURE;
		goto bam_add_desc_error;
	}

	/* Check if we have enough space in FIFO */
	if (len > (unsigned)bam->pipe[pipe_num].fifo.size * bam->max_desc_len) {
		printf("bam: Data transfer exceeds desc fifo length.\n");
		bam_ret = BAM_RESULT_FAILURE;
		goto bam_add_desc_error;
	}

	while (len) {
		/* There are only 16 bits to write data length.
		 * If more bits are needed, create more
		 * descriptors.
		 */
		if (len > bam->max_desc_len) {
			desc_len = bam->max_desc_len;
			len -= bam->max_desc_len;
			desc_flags = 0;
		} else {
			desc_len = len;
			len = 0;
			/* Set correct flags on the last desc. */
			desc_flags = flags;
		}

		/* Write descriptor */
		bam_add_one_desc(bam, pipe_num, data_ptr, desc_len, desc_flags);

		data_ptr += bam->max_desc_len;
		n++;
	}


	/* Create a read/write event to notify the periperal of the added desc. */
	bam_sys_gen_event(bam, pipe_num, n);

bam_add_desc_error:

	return bam_ret;
}

/* Function to add a BAM descriptor for a given fifo.
 * bam : BAM instance to be used.
 * data_ptr : Memory address for data transfer.
 * data_len : Length of the data_ptr.
 * flags : Flags to be set on the desc added.
 *
 * Note: This function does not notify the BAM about the added descriptor.
 */
int bam_add_one_desc(struct bam_instance *bam,
                     unsigned int pipe_num,
                     unsigned char* data_ptr,
                     uint32_t len,
                     uint8_t flags)
{

	struct bam_desc *desc = bam->pipe[pipe_num].fifo.current;
	int bam_ret = BAM_RESULT_SUCCESS;

	if (data_ptr == NULL || len == 0) {
		printf("bam: Wrong params for BAM transfer \n");
		bam_ret = BAM_RESULT_FAILURE;
		goto bam_add_one_desc_error;
	}

	/* Check if the FIFO is allocated for the pipe */
	if (!bam->pipe[pipe_num].initialized) {
		printf("bam: Please allocate the FIFO for the BAM pipe %d\n",
				bam->pipe[pipe_num].pipe_num);
		bam_ret = BAM_RESULT_FAILURE;
		goto bam_add_one_desc_error;
	}

	if ((flags & BAM_DESC_LOCK_FLAG) && (flags & BAM_DESC_UNLOCK_FLAG)) {
		printf("bam: Can't lock and unlock in the same desc\n");
		bam_ret = BAM_RESULT_FAILURE;
		goto bam_add_one_desc_error;
	}

	/* Setting EOT flag on a CMD desc is not valid */
	if ((flags & BAM_DESC_EOT_FLAG) && (flags & BAM_DESC_CMD_FLAG)) {
		printf("bam: EOT flag set on the CMD desc\n");
		bam_ret = BAM_RESULT_FAILURE;
		goto bam_add_one_desc_error;
	}

	/* Check for the length of the desc. */
	if (len > bam->max_desc_len) {
		printf("bam: len of the desc exceeds max length"
				" %d > %d\n", len, bam->max_desc_len);
		bam_ret = BAM_RESULT_FAILURE;
		goto bam_add_one_desc_error;
	}

	desc->flags    = flags;
	desc->addr     = (uint32_t)data_ptr;
	desc->size     = (uint16_t)len;
	desc->reserved = 0;

#if !defined(CONFIG_SYS_DCACHE_OFF)
	flush_dcache_range((addr_t)desc, ((addr_t)desc + BAM_DESC_SIZE));
	flush_dcache_range((addr_t)data_ptr, (addr_t)data_ptr + len);
#endif

	/* Update the FIFO to point to the head */
	bam->pipe[pipe_num].fifo.current = fifo_getnext(&bam->pipe[pipe_num].fifo, desc);

bam_add_one_desc_error:
	return bam_ret;
}

struct cmd_element* bam_add_cmd_element(struct cmd_element *ptr,
                                        uint32_t reg_addr,
                                        uint32_t value,
                                        enum bam_ce_cmd_t cmd_type)
{
	/* Write cmd type.
	 * Also, write the register address.
	 */
	ptr->addr_n_cmd = (reg_addr & ~(BAM_CE_REG_ADDR_MASK)) |
				(cmd_type << (BAM_CE_CMD_TYPE_SHIFT));

	/* Do not mask any of the addr bits by default */
	ptr->reg_mask = BAM_CE_REG_MASK;

	/* Write the value to be written */
	ptr->reg_data = value;

#if !defined(CONFIG_SYS_DCACHE_OFF)
	if(cmd_type == CE_READ_TYPE)
		flush_dcache_range((addr_t)value,
					((addr_t)value + sizeof(uint32_t)));
#endif

	/* Return the address to add the next element to */
	return ptr + 1;
}