+++ /dev/null
-/*
- * arch/arm/mach-ep93xx/dma-m2p.c
- * M2P DMA handling for Cirrus EP93xx chips.
- *
- * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
- * Copyright (C) 2006 Applied Data Systems
- *
- * Copyright (C) 2009 Ryan Mallon <ryan@bluewatersys.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or (at
- * your option) any later version.
- */
-
-/*
- * On the EP93xx chip the following peripherals my be allocated to the 10
- * Memory to Internal Peripheral (M2P) channels (5 transmit + 5 receive).
- *
- * I2S contains 3 Tx and 3 Rx DMA Channels
- * AAC contains 3 Tx and 3 Rx DMA Channels
- * UART1 contains 1 Tx and 1 Rx DMA Channels
- * UART2 contains 1 Tx and 1 Rx DMA Channels
- * UART3 contains 1 Tx and 1 Rx DMA Channels
- * IrDA contains 1 Tx and 1 Rx DMA Channels
- *
- * SSP and IDE use the Memory to Memory (M2M) channels and are not covered
- * with this implementation.
- */
-
-#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt
-
-#include <linux/kernel.h>
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/interrupt.h>
-#include <linux/module.h>
-#include <linux/io.h>
-
-#include <mach/dma.h>
-#include <mach/hardware.h>
-
-#define M2P_CONTROL 0x00
-#define M2P_CONTROL_STALL_IRQ_EN (1 << 0)
-#define M2P_CONTROL_NFB_IRQ_EN (1 << 1)
-#define M2P_CONTROL_ERROR_IRQ_EN (1 << 3)
-#define M2P_CONTROL_ENABLE (1 << 4)
-#define M2P_INTERRUPT 0x04
-#define M2P_INTERRUPT_STALL (1 << 0)
-#define M2P_INTERRUPT_NFB (1 << 1)
-#define M2P_INTERRUPT_ERROR (1 << 3)
-#define M2P_PPALLOC 0x08
-#define M2P_STATUS 0x0c
-#define M2P_REMAIN 0x14
-#define M2P_MAXCNT0 0x20
-#define M2P_BASE0 0x24
-#define M2P_MAXCNT1 0x30
-#define M2P_BASE1 0x34
-
-#define STATE_IDLE 0 /* Channel is inactive. */
-#define STATE_STALL 1 /* Channel is active, no buffers pending. */
-#define STATE_ON 2 /* Channel is active, one buffer pending. */
-#define STATE_NEXT 3 /* Channel is active, two buffers pending. */
-
-struct m2p_channel {
- char *name;
- void __iomem *base;
- int irq;
-
- struct clk *clk;
- spinlock_t lock;
-
- void *client;
- unsigned next_slot:1;
- struct ep93xx_dma_buffer *buffer_xfer;
- struct ep93xx_dma_buffer *buffer_next;
- struct list_head buffers_pending;
-};
-
-static struct m2p_channel m2p_rx[] = {
- {"m2p1", EP93XX_DMA_BASE + 0x0040, IRQ_EP93XX_DMAM2P1},
- {"m2p3", EP93XX_DMA_BASE + 0x00c0, IRQ_EP93XX_DMAM2P3},
- {"m2p5", EP93XX_DMA_BASE + 0x0200, IRQ_EP93XX_DMAM2P5},
- {"m2p7", EP93XX_DMA_BASE + 0x0280, IRQ_EP93XX_DMAM2P7},
- {"m2p9", EP93XX_DMA_BASE + 0x0300, IRQ_EP93XX_DMAM2P9},
- {NULL},
-};
-
-static struct m2p_channel m2p_tx[] = {
- {"m2p0", EP93XX_DMA_BASE + 0x0000, IRQ_EP93XX_DMAM2P0},
- {"m2p2", EP93XX_DMA_BASE + 0x0080, IRQ_EP93XX_DMAM2P2},
- {"m2p4", EP93XX_DMA_BASE + 0x0240, IRQ_EP93XX_DMAM2P4},
- {"m2p6", EP93XX_DMA_BASE + 0x02c0, IRQ_EP93XX_DMAM2P6},
- {"m2p8", EP93XX_DMA_BASE + 0x0340, IRQ_EP93XX_DMAM2P8},
- {NULL},
-};
-
-static void feed_buf(struct m2p_channel *ch, struct ep93xx_dma_buffer *buf)
-{
- if (ch->next_slot == 0) {
- writel(buf->size, ch->base + M2P_MAXCNT0);
- writel(buf->bus_addr, ch->base + M2P_BASE0);
- } else {
- writel(buf->size, ch->base + M2P_MAXCNT1);
- writel(buf->bus_addr, ch->base + M2P_BASE1);
- }
- ch->next_slot ^= 1;
-}
-
-static void choose_buffer_xfer(struct m2p_channel *ch)
-{
- struct ep93xx_dma_buffer *buf;
-
- ch->buffer_xfer = NULL;
- if (!list_empty(&ch->buffers_pending)) {
- buf = list_entry(ch->buffers_pending.next,
- struct ep93xx_dma_buffer, list);
- list_del(&buf->list);
- feed_buf(ch, buf);
- ch->buffer_xfer = buf;
- }
-}
-
-static void choose_buffer_next(struct m2p_channel *ch)
-{
- struct ep93xx_dma_buffer *buf;
-
- ch->buffer_next = NULL;
- if (!list_empty(&ch->buffers_pending)) {
- buf = list_entry(ch->buffers_pending.next,
- struct ep93xx_dma_buffer, list);
- list_del(&buf->list);
- feed_buf(ch, buf);
- ch->buffer_next = buf;
- }
-}
-
-static inline void m2p_set_control(struct m2p_channel *ch, u32 v)
-{
- /*
- * The control register must be read immediately after being written so
- * that the internal state machine is correctly updated. See the ep93xx
- * users' guide for details.
- */
- writel(v, ch->base + M2P_CONTROL);
- readl(ch->base + M2P_CONTROL);
-}
-
-static inline int m2p_channel_state(struct m2p_channel *ch)
-{
- return (readl(ch->base + M2P_STATUS) >> 4) & 0x3;
-}
-
-static irqreturn_t m2p_irq(int irq, void *dev_id)
-{
- struct m2p_channel *ch = dev_id;
- struct ep93xx_dma_m2p_client *cl;
- u32 irq_status, v;
- int error = 0;
-
- cl = ch->client;
-
- spin_lock(&ch->lock);
- irq_status = readl(ch->base + M2P_INTERRUPT);
-
- if (irq_status & M2P_INTERRUPT_ERROR) {
- writel(M2P_INTERRUPT_ERROR, ch->base + M2P_INTERRUPT);
- error = 1;
- }
-
- if ((irq_status & (M2P_INTERRUPT_STALL | M2P_INTERRUPT_NFB)) == 0) {
- spin_unlock(&ch->lock);
- return IRQ_NONE;
- }
-
- switch (m2p_channel_state(ch)) {
- case STATE_IDLE:
- pr_crit("dma interrupt without a dma buffer\n");
- BUG();
- break;
-
- case STATE_STALL:
- cl->buffer_finished(cl->cookie, ch->buffer_xfer, 0, error);
- if (ch->buffer_next != NULL) {
- cl->buffer_finished(cl->cookie, ch->buffer_next,
- 0, error);
- }
- choose_buffer_xfer(ch);
- choose_buffer_next(ch);
- if (ch->buffer_xfer != NULL)
- cl->buffer_started(cl->cookie, ch->buffer_xfer);
- break;
-
- case STATE_ON:
- cl->buffer_finished(cl->cookie, ch->buffer_xfer, 0, error);
- ch->buffer_xfer = ch->buffer_next;
- choose_buffer_next(ch);
- cl->buffer_started(cl->cookie, ch->buffer_xfer);
- break;
-
- case STATE_NEXT:
- pr_crit("dma interrupt while next\n");
- BUG();
- break;
- }
-
- v = readl(ch->base + M2P_CONTROL) & ~(M2P_CONTROL_STALL_IRQ_EN |
- M2P_CONTROL_NFB_IRQ_EN);
- if (ch->buffer_xfer != NULL)
- v |= M2P_CONTROL_STALL_IRQ_EN;
- if (ch->buffer_next != NULL)
- v |= M2P_CONTROL_NFB_IRQ_EN;
- m2p_set_control(ch, v);
-
- spin_unlock(&ch->lock);
- return IRQ_HANDLED;
-}
-
-static struct m2p_channel *find_free_channel(struct ep93xx_dma_m2p_client *cl)
-{
- struct m2p_channel *ch;
- int i;
-
- if (cl->flags & EP93XX_DMA_M2P_RX)
- ch = m2p_rx;
- else
- ch = m2p_tx;
-
- for (i = 0; ch[i].base; i++) {
- struct ep93xx_dma_m2p_client *client;
-
- client = ch[i].client;
- if (client != NULL) {
- int port;
-
- port = cl->flags & EP93XX_DMA_M2P_PORT_MASK;
- if (port == (client->flags &
- EP93XX_DMA_M2P_PORT_MASK)) {
- pr_warning("DMA channel already used by %s\n",
- cl->name ? : "unknown client");
- return ERR_PTR(-EBUSY);
- }
- }
- }
-
- for (i = 0; ch[i].base; i++) {
- if (ch[i].client == NULL)
- return ch + i;
- }
-
- pr_warning("No free DMA channel for %s\n",
- cl->name ? : "unknown client");
- return ERR_PTR(-ENODEV);
-}
-
-static void channel_enable(struct m2p_channel *ch)
-{
- struct ep93xx_dma_m2p_client *cl = ch->client;
- u32 v;
-
- clk_enable(ch->clk);
-
- v = cl->flags & EP93XX_DMA_M2P_PORT_MASK;
- writel(v, ch->base + M2P_PPALLOC);
-
- v = cl->flags & EP93XX_DMA_M2P_ERROR_MASK;
- v |= M2P_CONTROL_ENABLE | M2P_CONTROL_ERROR_IRQ_EN;
- m2p_set_control(ch, v);
-}
-
-static void channel_disable(struct m2p_channel *ch)
-{
- u32 v;
-
- v = readl(ch->base + M2P_CONTROL);
- v &= ~(M2P_CONTROL_STALL_IRQ_EN | M2P_CONTROL_NFB_IRQ_EN);
- m2p_set_control(ch, v);
-
- while (m2p_channel_state(ch) >= STATE_ON)
- cpu_relax();
-
- m2p_set_control(ch, 0x0);
-
- while (m2p_channel_state(ch) == STATE_STALL)
- cpu_relax();
-
- clk_disable(ch->clk);
-}
-
-int ep93xx_dma_m2p_client_register(struct ep93xx_dma_m2p_client *cl)
-{
- struct m2p_channel *ch;
- int err;
-
- ch = find_free_channel(cl);
- if (IS_ERR(ch))
- return PTR_ERR(ch);
-
- err = request_irq(ch->irq, m2p_irq, 0, cl->name ? : "dma-m2p", ch);
- if (err)
- return err;
-
- ch->client = cl;
- ch->next_slot = 0;
- ch->buffer_xfer = NULL;
- ch->buffer_next = NULL;
- INIT_LIST_HEAD(&ch->buffers_pending);
-
- cl->channel = ch;
-
- channel_enable(ch);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(ep93xx_dma_m2p_client_register);
-
-void ep93xx_dma_m2p_client_unregister(struct ep93xx_dma_m2p_client *cl)
-{
- struct m2p_channel *ch = cl->channel;
-
- channel_disable(ch);
- free_irq(ch->irq, ch);
- ch->client = NULL;
-}
-EXPORT_SYMBOL_GPL(ep93xx_dma_m2p_client_unregister);
-
-void ep93xx_dma_m2p_submit(struct ep93xx_dma_m2p_client *cl,
- struct ep93xx_dma_buffer *buf)
-{
- struct m2p_channel *ch = cl->channel;
- unsigned long flags;
- u32 v;
-
- spin_lock_irqsave(&ch->lock, flags);
- v = readl(ch->base + M2P_CONTROL);
- if (ch->buffer_xfer == NULL) {
- ch->buffer_xfer = buf;
- feed_buf(ch, buf);
- cl->buffer_started(cl->cookie, buf);
-
- v |= M2P_CONTROL_STALL_IRQ_EN;
- m2p_set_control(ch, v);
-
- } else if (ch->buffer_next == NULL) {
- ch->buffer_next = buf;
- feed_buf(ch, buf);
-
- v |= M2P_CONTROL_NFB_IRQ_EN;
- m2p_set_control(ch, v);
- } else {
- list_add_tail(&buf->list, &ch->buffers_pending);
- }
- spin_unlock_irqrestore(&ch->lock, flags);
-}
-EXPORT_SYMBOL_GPL(ep93xx_dma_m2p_submit);
-
-void ep93xx_dma_m2p_submit_recursive(struct ep93xx_dma_m2p_client *cl,
- struct ep93xx_dma_buffer *buf)
-{
- struct m2p_channel *ch = cl->channel;
-
- list_add_tail(&buf->list, &ch->buffers_pending);
-}
-EXPORT_SYMBOL_GPL(ep93xx_dma_m2p_submit_recursive);
-
-void ep93xx_dma_m2p_flush(struct ep93xx_dma_m2p_client *cl)
-{
- struct m2p_channel *ch = cl->channel;
-
- channel_disable(ch);
- ch->next_slot = 0;
- ch->buffer_xfer = NULL;
- ch->buffer_next = NULL;
- INIT_LIST_HEAD(&ch->buffers_pending);
- channel_enable(ch);
-}
-EXPORT_SYMBOL_GPL(ep93xx_dma_m2p_flush);
-
-static int init_channel(struct m2p_channel *ch)
-{
- ch->clk = clk_get(NULL, ch->name);
- if (IS_ERR(ch->clk))
- return PTR_ERR(ch->clk);
-
- spin_lock_init(&ch->lock);
- ch->client = NULL;
-
- return 0;
-}
-
-static int __init ep93xx_dma_m2p_init(void)
-{
- int i;
- int ret;
-
- for (i = 0; m2p_rx[i].base; i++) {
- ret = init_channel(m2p_rx + i);
- if (ret)
- return ret;
- }
-
- for (i = 0; m2p_tx[i].base; i++) {
- ret = init_channel(m2p_tx + i);
- if (ret)
- return ret;
- }
-
- pr_info("M2P DMA subsystem initialized\n");
- return 0;
-}
-arch_initcall(ep93xx_dma_m2p_init);
-/**
- * DOC: EP93xx DMA M2P memory to peripheral and peripheral to memory engine
- *
- * The EP93xx DMA M2P subsystem handles DMA transfers between memory and
- * peripherals. DMA M2P channels are available for audio, UARTs and IrDA.
- * See chapter 10 of the EP93xx users guide for full details on the DMA M2P
- * engine.
- *
- * See sound/soc/ep93xx/ep93xx-pcm.c for an example use of the DMA M2P code.
- *
- */
-
#ifndef __ASM_ARCH_DMA_H
#define __ASM_ARCH_DMA_H
-#include <linux/list.h>
#include <linux/types.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
-/**
- * struct ep93xx_dma_buffer - Information about a buffer to be transferred
- * using the DMA M2P engine
- *
- * @list: Entry in DMA buffer list
- * @bus_addr: Physical address of the buffer
- * @size: Size of the buffer in bytes
- */
-struct ep93xx_dma_buffer {
- struct list_head list;
- u32 bus_addr;
- u16 size;
-};
-
-/**
- * struct ep93xx_dma_m2p_client - Information about a DMA M2P client
- *
- * @name: Unique name for this client
- * @flags: Client flags
- * @cookie: User data to pass to callback functions
- * @buffer_started: Non NULL function to call when a transfer is started.
- * The arguments are the user data cookie and the DMA
- * buffer which is starting.
- * @buffer_finished: Non NULL function to call when a transfer is completed.
- * The arguments are the user data cookie, the DMA buffer
- * which has completed, and a boolean flag indicating if
- * the transfer had an error.
- */
-struct ep93xx_dma_m2p_client {
- char *name;
- u8 flags;
- void *cookie;
- void (*buffer_started)(void *cookie,
- struct ep93xx_dma_buffer *buf);
- void (*buffer_finished)(void *cookie,
- struct ep93xx_dma_buffer *buf,
- int bytes, int error);
-
- /* private: Internal use only */
- void *channel;
-};
-
-/* DMA M2P ports */
-#define EP93XX_DMA_M2P_PORT_I2S1 0x00
-#define EP93XX_DMA_M2P_PORT_I2S2 0x01
-#define EP93XX_DMA_M2P_PORT_AAC1 0x02
-#define EP93XX_DMA_M2P_PORT_AAC2 0x03
-#define EP93XX_DMA_M2P_PORT_AAC3 0x04
-#define EP93XX_DMA_M2P_PORT_I2S3 0x05
-#define EP93XX_DMA_M2P_PORT_UART1 0x06
-#define EP93XX_DMA_M2P_PORT_UART2 0x07
-#define EP93XX_DMA_M2P_PORT_UART3 0x08
-#define EP93XX_DMA_M2P_PORT_IRDA 0x09
-#define EP93XX_DMA_M2P_PORT_MASK 0x0f
-
-/* DMA M2P client flags */
-#define EP93XX_DMA_M2P_TX 0x00 /* Memory to peripheral */
-#define EP93XX_DMA_M2P_RX 0x10 /* Peripheral to memory */
-
-/*
- * DMA M2P client error handling flags. See the EP93xx users guide
- * documentation on the DMA M2P CONTROL register for more details
- */
-#define EP93XX_DMA_M2P_ABORT_ON_ERROR 0x20 /* Abort on peripheral error */
-#define EP93XX_DMA_M2P_IGNORE_ERROR 0x40 /* Ignore peripheral errors */
-#define EP93XX_DMA_M2P_ERROR_MASK 0x60 /* Mask of error bits */
-
-/**
- * ep93xx_dma_m2p_client_register - Register a client with the DMA M2P
- * subsystem
- *
- * @m2p: Client information to register
- * returns 0 on success
- *
- * The DMA M2P subsystem allocates a channel and an interrupt line for the DMA
- * client
- */
-int ep93xx_dma_m2p_client_register(struct ep93xx_dma_m2p_client *m2p);
-
-/**
- * ep93xx_dma_m2p_client_unregister - Unregister a client from the DMA M2P
- * subsystem
- *
- * @m2p: Client to unregister
- *
- * Any transfers currently in progress will be completed in hardware, but
- * ignored in software.
- */
-void ep93xx_dma_m2p_client_unregister(struct ep93xx_dma_m2p_client *m2p);
-
-/**
- * ep93xx_dma_m2p_submit - Submit a DMA M2P transfer
- *
- * @m2p: DMA Client to submit the transfer on
- * @buf: DMA Buffer to submit
- *
- * If the current or next transfer positions are free on the M2P client then
- * the transfer is started immediately. If not, the transfer is added to the
- * list of pending transfers. This function must not be called from the
- * buffer_finished callback for an M2P channel.
- *
- */
-void ep93xx_dma_m2p_submit(struct ep93xx_dma_m2p_client *m2p,
- struct ep93xx_dma_buffer *buf);
-
-/**
- * ep93xx_dma_m2p_submit_recursive - Put a DMA transfer on the pending list
- * for an M2P channel
- *
- * @m2p: DMA Client to submit the transfer on
- * @buf: DMA Buffer to submit
- *
- * This function must only be called from the buffer_finished callback for an
- * M2P channel. It is commonly used to add the next transfer in a chained list
- * of DMA transfers.
- */
-void ep93xx_dma_m2p_submit_recursive(struct ep93xx_dma_m2p_client *m2p,
- struct ep93xx_dma_buffer *buf);
-
-/**
- * ep93xx_dma_m2p_flush - Flush all pending transfers on a DMA M2P client
- *
- * @m2p: DMA client to flush transfers on
- *
- * Any transfers currently in progress will be completed in hardware, but
- * ignored in software.
- *
- */
-void ep93xx_dma_m2p_flush(struct ep93xx_dma_m2p_client *m2p);
-
/*
* M2P channels.
*
git.openpandora.org / pandora-kernel.git / commitdiff