linux-imx

/*

 * Copyright 2016 Broadcom

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License, version 2, as

 * published by the Free Software Foundation (the "GPL").

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License version 2 (GPLv2) for more details.

 *

 * You should have received a copy of the GNU General Public License

 * version 2 (GPLv2) along with this source code.

 */

​

/*

 * Broadcom PDC Mailbox Driver

 * The PDC provides a ring based programming interface to one or more hardware

 * offload engines. For example, the PDC driver works with both SPU-M and SPU2

 * cryptographic offload hardware. In some chips the PDC is referred to as MDE,

 * and in others the FA2/FA+ hardware is used with this PDC driver.

 *

 * The PDC driver registers with the Linux mailbox framework as a mailbox

 * controller, once for each PDC instance. Ring 0 for each PDC is registered as

 * a mailbox channel. The PDC driver uses interrupts to determine when data

 * transfers to and from an offload engine are complete. The PDC driver uses

 * threaded IRQs so that response messages are handled outside of interrupt

 * context.

 *

 * The PDC driver allows multiple messages to be pending in the descriptor

 * rings. The tx_msg_start descriptor index indicates where the last message

 * starts. The txin_numd value at this index indicates how many descriptor

 * indexes make up the message. Similar state is kept on the receive side. When

 * an rx interrupt indicates a response is ready, the PDC driver processes numd

 * descriptors from the tx and rx ring, thus processing one response at a time.

 */

​

#include <linux/errno.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/debugfs.h>

#include <linux/interrupt.h>

#include <linux/wait.h>

#include <linux/platform_device.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/of_address.h>

#include <linux/of_irq.h>

#include <linux/mailbox_controller.h>

#include <linux/mailbox/brcm-message.h>

#include <linux/scatterlist.h>

#include <linux/dma-direction.h>

#include <linux/dma-mapping.h>

#include <linux/dmapool.h>

​

#define PDC_SUCCESS  0

​

#define RING_ENTRY_SIZE   sizeof(struct dma64dd)

​

/* # entries in PDC dma ring */

#define PDC_RING_ENTRIES  512

/*

 * Minimum number of ring descriptor entries that must be free to tell mailbox

 * framework that it can submit another request

 */

#define PDC_RING_SPACE_MIN  15

​

#define PDC_RING_SIZE    (PDC_RING_ENTRIES * RING_ENTRY_SIZE)

/* Rings are 8k aligned */

#define RING_ALIGN_ORDER  13

#define RING_ALIGN        BIT(RING_ALIGN_ORDER)

​

#define RX_BUF_ALIGN_ORDER  5

#define RX_BUF_ALIGN        BIT(RX_BUF_ALIGN_ORDER)

​

/* descriptor bumping macros */

#define XXD(x, max_mask)              ((x) & (max_mask))

#define TXD(x, max_mask)              XXD((x), (max_mask))

#define RXD(x, max_mask)              XXD((x), (max_mask))

#define NEXTTXD(i, max_mask)          TXD((i) + 1, (max_mask))

#define PREVTXD(i, max_mask)          TXD((i) - 1, (max_mask))

#define NEXTRXD(i, max_mask)          RXD((i) + 1, (max_mask))

#define PREVRXD(i, max_mask)          RXD((i) - 1, (max_mask))

#define NTXDACTIVE(h, t, max_mask)    TXD((t) - (h), (max_mask))

#define NRXDACTIVE(h, t, max_mask)    RXD((t) - (h), (max_mask))

​

/* Length of BCM header at start of SPU msg, in bytes */

#define BCM_HDR_LEN  8

​