--- /dev/null
+/*
+ * Driver for the Cirrus Logic EP93xx DMA Controller
+ *
+ * Copyright (C) 2011 Mika Westerberg
+ *
+ * DMA M2P implementation is based on the original
+ * arch/arm/mach-ep93xx/dma-m2p.c which has following copyrights:
+ *
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ * Copyright (C) 2006 Applied Data Systems
+ * Copyright (C) 2009 Ryan Mallon <rmallon@gmail.com>
+ *
+ * This driver is based on dw_dmac and amba-pl08x drivers.
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <mach/dma.h>
+
+/* M2P registers */
+#define M2P_CONTROL 0x0000
+#define M2P_CONTROL_STALLINT BIT(0)
+#define M2P_CONTROL_NFBINT BIT(1)
+#define M2P_CONTROL_CH_ERROR_INT BIT(3)
+#define M2P_CONTROL_ENABLE BIT(4)
+#define M2P_CONTROL_ICE BIT(6)
+
+#define M2P_INTERRUPT 0x0004
+#define M2P_INTERRUPT_STALL BIT(0)
+#define M2P_INTERRUPT_NFB BIT(1)
+#define M2P_INTERRUPT_ERROR BIT(3)
+
+#define M2P_PPALLOC 0x0008
+#define M2P_STATUS 0x000c
+
+#define M2P_MAXCNT0 0x0020
+#define M2P_BASE0 0x0024
+#define M2P_MAXCNT1 0x0030
+#define M2P_BASE1 0x0034
+
+#define M2P_STATE_IDLE 0
+#define M2P_STATE_STALL 1
+#define M2P_STATE_ON 2
+#define M2P_STATE_NEXT 3
+
+/* M2M registers */
+#define M2M_CONTROL 0x0000
+#define M2M_CONTROL_DONEINT BIT(2)
+#define M2M_CONTROL_ENABLE BIT(3)
+#define M2M_CONTROL_START BIT(4)
+#define M2M_CONTROL_DAH BIT(11)
+#define M2M_CONTROL_SAH BIT(12)
+#define M2M_CONTROL_PW_SHIFT 9
+#define M2M_CONTROL_PW_8 (0 << M2M_CONTROL_PW_SHIFT)
+#define M2M_CONTROL_PW_16 (1 << M2M_CONTROL_PW_SHIFT)
+#define M2M_CONTROL_PW_32 (2 << M2M_CONTROL_PW_SHIFT)
+#define M2M_CONTROL_PW_MASK (3 << M2M_CONTROL_PW_SHIFT)
+#define M2M_CONTROL_TM_SHIFT 13
+#define M2M_CONTROL_TM_TX (1 << M2M_CONTROL_TM_SHIFT)
+#define M2M_CONTROL_TM_RX (2 << M2M_CONTROL_TM_SHIFT)
+#define M2M_CONTROL_RSS_SHIFT 22
+#define M2M_CONTROL_RSS_SSPRX (1 << M2M_CONTROL_RSS_SHIFT)
+#define M2M_CONTROL_RSS_SSPTX (2 << M2M_CONTROL_RSS_SHIFT)
+#define M2M_CONTROL_RSS_IDE (3 << M2M_CONTROL_RSS_SHIFT)
+#define M2M_CONTROL_NO_HDSK BIT(24)
+#define M2M_CONTROL_PWSC_SHIFT 25
+
+#define M2M_INTERRUPT 0x0004
+#define M2M_INTERRUPT_DONEINT BIT(1)
+
+#define M2M_BCR0 0x0010
+#define M2M_BCR1 0x0014
+#define M2M_SAR_BASE0 0x0018
+#define M2M_SAR_BASE1 0x001c
+#define M2M_DAR_BASE0 0x002c
+#define M2M_DAR_BASE1 0x0030
+
+#define DMA_MAX_CHAN_BYTES 0xffff
+#define DMA_MAX_CHAN_DESCRIPTORS 32
+
+struct ep93xx_dma_engine;
+
+/**
+ * struct ep93xx_dma_desc - EP93xx specific transaction descriptor
+ * @src_addr: source address of the transaction
+ * @dst_addr: destination address of the transaction
+ * @size: size of the transaction (in bytes)
+ * @complete: this descriptor is completed
+ * @txd: dmaengine API descriptor
+ * @tx_list: list of linked descriptors
+ * @node: link used for putting this into a channel queue
+ */
+struct ep93xx_dma_desc {
+ u32 src_addr;
+ u32 dst_addr;
+ size_t size;
+ bool complete;
+ struct dma_async_tx_descriptor txd;
+ struct list_head tx_list;
+ struct list_head node;
+};
+
+/**
+ * struct ep93xx_dma_chan - an EP93xx DMA M2P/M2M channel
+ * @chan: dmaengine API channel
+ * @edma: pointer to to the engine device
+ * @regs: memory mapped registers
+ * @irq: interrupt number of the channel
+ * @clk: clock used by this channel
+ * @tasklet: channel specific tasklet used for callbacks
+ * @lock: lock protecting the fields following
+ * @flags: flags for the channel
+ * @buffer: which buffer to use next (0/1)
+ * @last_completed: last completed cookie value
+ * @active: flattened chain of descriptors currently being processed
+ * @queue: pending descriptors which are handled next
+ * @free_list: list of free descriptors which can be used
+ * @runtime_addr: physical address currently used as dest/src (M2M only). This
+ * is set via %DMA_SLAVE_CONFIG before slave operation is
+ * prepared
+ * @runtime_ctrl: M2M runtime values for the control register.
+ *
+ * As EP93xx DMA controller doesn't support real chained DMA descriptors we
+ * will have slightly different scheme here: @active points to a head of
+ * flattened DMA descriptor chain.
+ *
+ * @queue holds pending transactions. These are linked through the first
+ * descriptor in the chain. When a descriptor is moved to the @active queue,
+ * the first and chained descriptors are flattened into a single list.
+ *
+ * @chan.private holds pointer to &struct ep93xx_dma_data which contains
+ * necessary channel configuration information. For memcpy channels this must
+ * be %NULL.
+ */
+struct ep93xx_dma_chan {
+ struct dma_chan chan;
+ const struct ep93xx_dma_engine *edma;
+ void __iomem *regs;
+ int irq;
+ struct clk *clk;
+ struct tasklet_struct tasklet;
+ /* protects the fields following */
+ spinlock_t lock;
+ unsigned long flags;
+/* Channel is configured for cyclic transfers */
+#define EP93XX_DMA_IS_CYCLIC 0
+
+ int buffer;
+ dma_cookie_t last_completed;
+ struct list_head active;
+ struct list_head queue;
+ struct list_head free_list;
+ u32 runtime_addr;
+ u32 runtime_ctrl;
+};
+
+/**
+ * struct ep93xx_dma_engine - the EP93xx DMA engine instance
+ * @dma_dev: holds the dmaengine device
+ * @m2m: is this an M2M or M2P device
+ * @hw_setup: method which sets the channel up for operation
+ * @hw_shutdown: shuts the channel down and flushes whatever is left
+ * @hw_submit: pushes active descriptor(s) to the hardware
+ * @hw_interrupt: handle the interrupt
+ * @num_channels: number of channels for this instance
+ * @channels: array of channels
+ *
+ * There is one instance of this struct for the M2P channels and one for the
+ * M2M channels. hw_xxx() methods are used to perform operations which are
+ * different on M2M and M2P channels. These methods are called with channel
+ * lock held and interrupts disabled so they cannot sleep.
+ */
+struct ep93xx_dma_engine {
+ struct dma_device dma_dev;
+ bool m2m;
+ int (*hw_setup)(struct ep93xx_dma_chan *);
+ void (*hw_shutdown)(struct ep93xx_dma_chan *);
+ void (*hw_submit)(struct ep93xx_dma_chan *);
+ int (*hw_interrupt)(struct ep93xx_dma_chan *);
+#define INTERRUPT_UNKNOWN 0
+#define INTERRUPT_DONE 1
+#define INTERRUPT_NEXT_BUFFER 2
+
+ size_t num_channels;
+ struct ep93xx_dma_chan channels[];
+};
+
+static inline struct device *chan2dev(struct ep93xx_dma_chan *edmac)
+{
+ return &edmac->chan.dev->device;
+}
+
+static struct ep93xx_dma_chan *to_ep93xx_dma_chan(struct dma_chan *chan)
+{
+ return container_of(chan, struct ep93xx_dma_chan, chan);
+}
+
+/**
+ * ep93xx_dma_set_active - set new active descriptor chain
+ * @edmac: channel
+ * @desc: head of the new active descriptor chain
+ *
+ * Sets @desc to be the head of the new active descriptor chain. This is the
+ * chain which is processed next. The active list must be empty before calling
+ * this function.
+ *
+ * Called with @edmac->lock held and interrupts disabled.
+ */
+static void ep93xx_dma_set_active(struct ep93xx_dma_chan *edmac,
+ struct ep93xx_dma_desc *desc)
+{
+ BUG_ON(!list_empty(&edmac->active));
+
+ list_add_tail(&desc->node, &edmac->active);
+
+ /* Flatten the @desc->tx_list chain into @edmac->active list */
+ while (!list_empty(&desc->tx_list)) {
+ struct ep93xx_dma_desc *d = list_first_entry(&desc->tx_list,
+ struct ep93xx_dma_desc, node);
+
+ /*
+ * We copy the callback parameters from the first descriptor
+ * to all the chained descriptors. This way we can call the
+ * callback without having to find out the first descriptor in
+ * the chain. Useful for cyclic transfers.
+ */
+ d->txd.callback = desc->txd.callback;
+ d->txd.callback_param = desc->txd.callback_param;
+
+ list_move_tail(&d->node, &edmac->active);
+ }
+}
+
+/* Called with @edmac->lock held and interrupts disabled */
+static struct ep93xx_dma_desc *
+ep93xx_dma_get_active(struct ep93xx_dma_chan *edmac)
+{
+ return list_first_entry(&edmac->active, struct ep93xx_dma_desc, node);
+}
+
+/**
+ * ep93xx_dma_advance_active - advances to the next active descriptor
+ * @edmac: channel
+ *
+ * Function advances active descriptor to the next in the @edmac->active and
+ * returns %true if we still have descriptors in the chain to process.
+ * Otherwise returns %false.
+ *
+ * When the channel is in cyclic mode always returns %true.
+ *
+ * Called with @edmac->lock held and interrupts disabled.
+ */
+static bool ep93xx_dma_advance_active(struct ep93xx_dma_chan *edmac)
+{
+ list_rotate_left(&edmac->active);
+
+ if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags))
+ return true;
+
+ /*
+ * If txd.cookie is set it means that we are back in the first
+ * descriptor in the chain and hence done with it.
+ */
+ return !ep93xx_dma_get_active(edmac)->txd.cookie;
+}
+
+/*
+ * M2P DMA implementation
+ */
+
+static void m2p_set_control(struct ep93xx_dma_chan *edmac, u32 control)
+{
+ writel(control, edmac->regs + M2P_CONTROL);
+ /*
+ * EP93xx User's Guide states that we must perform a dummy read after
+ * write to the control register.
+ */
+ readl(edmac->regs + M2P_CONTROL);
+}
+
+static int m2p_hw_setup(struct ep93xx_dma_chan *edmac)
+{
+ struct ep93xx_dma_data *data = edmac->chan.private;
+ u32 control;
+
+ writel(data->port & 0xf, edmac->regs + M2P_PPALLOC);
+
+ control = M2P_CONTROL_CH_ERROR_INT | M2P_CONTROL_ICE
+ | M2P_CONTROL_ENABLE;
+ m2p_set_control(edmac, control);
+
+ return 0;
+}
+
+static inline u32 m2p_channel_state(struct ep93xx_dma_chan *edmac)
+{
+ return (readl(edmac->regs + M2P_STATUS) >> 4) & 0x3;
+}
+
+static void m2p_hw_shutdown(struct ep93xx_dma_chan *edmac)
+{
+ u32 control;
+
+ control = readl(edmac->regs + M2P_CONTROL);
+ control &= ~(M2P_CONTROL_STALLINT | M2P_CONTROL_NFBINT);
+ m2p_set_control(edmac, control);
+
+ while (m2p_channel_state(edmac) >= M2P_STATE_ON)
+ cpu_relax();
+
+ m2p_set_control(edmac, 0);
+
+ while (m2p_channel_state(edmac) == M2P_STATE_STALL)
+ cpu_relax();
+}
+
+static void m2p_fill_desc(struct ep93xx_dma_chan *edmac)
+{
+ struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac);
+ u32 bus_addr;
+
+ if (ep93xx_dma_chan_direction(&edmac->chan) == DMA_TO_DEVICE)
+ bus_addr = desc->src_addr;
+ else
+ bus_addr = desc->dst_addr;
+
+ if (edmac->buffer == 0) {
+ writel(desc->size, edmac->regs + M2P_MAXCNT0);
+ writel(bus_addr, edmac->regs + M2P_BASE0);
+ } else {
+ writel(desc->size, edmac->regs + M2P_MAXCNT1);
+ writel(bus_addr, edmac->regs + M2P_BASE1);
+ }
+
+ edmac->buffer ^= 1;
+}
+
+static void m2p_hw_submit(struct ep93xx_dma_chan *edmac)
+{
+ u32 control = readl(edmac->regs + M2P_CONTROL);
+
+ m2p_fill_desc(edmac);
+ control |= M2P_CONTROL_STALLINT;
+
+ if (ep93xx_dma_advance_active(edmac)) {
+ m2p_fill_desc(edmac);
+ control |= M2P_CONTROL_NFBINT;
+ }
+
+ m2p_set_control(edmac, control);
+}
+
+static int m2p_hw_interrupt(struct ep93xx_dma_chan *edmac)
+{
+ u32 irq_status = readl(edmac->regs + M2P_INTERRUPT);
+ u32 control;
+
+ if (irq_status & M2P_INTERRUPT_ERROR) {
+ struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac);
+
+ /* Clear the error interrupt */
+ writel(1, edmac->regs + M2P_INTERRUPT);
+
+ /*
+ * It seems that there is no easy way of reporting errors back
+ * to client so we just report the error here and continue as
+ * usual.
+ *
+ * Revisit this when there is a mechanism to report back the
+ * errors.
+ */
+ dev_err(chan2dev(edmac),
+ "DMA transfer failed! Details:\n"
+ "\tcookie : %d\n"
+ "\tsrc_addr : 0x%08x\n"
+ "\tdst_addr : 0x%08x\n"
+ "\tsize : %zu\n",
+ desc->txd.cookie, desc->src_addr, desc->dst_addr,
+ desc->size);
+ }
+
+ switch (irq_status & (M2P_INTERRUPT_STALL | M2P_INTERRUPT_NFB)) {
+ case M2P_INTERRUPT_STALL:
+ /* Disable interrupts */
+ control = readl(edmac->regs + M2P_CONTROL);
+ control &= ~(M2P_CONTROL_STALLINT | M2P_CONTROL_NFBINT);
+ m2p_set_control(edmac, control);
+
+ return INTERRUPT_DONE;
+
+ case M2P_INTERRUPT_NFB:
+ if (ep93xx_dma_advance_active(edmac))
+ m2p_fill_desc(edmac);
+
+ return INTERRUPT_NEXT_BUFFER;
+ }
+
+ return INTERRUPT_UNKNOWN;
+}
+
+/*
+ * M2M DMA implementation
+ *
+ * For the M2M transfers we don't use NFB at all. This is because it simply
+ * doesn't work well with memcpy transfers. When you submit both buffers it is
+ * extremely unlikely that you get an NFB interrupt, but it instead reports
+ * DONE interrupt and both buffers are already transferred which means that we
+ * weren't able to update the next buffer.
+ *
+ * So for now we "simulate" NFB by just submitting buffer after buffer
+ * without double buffering.
+ */
+
+static int m2m_hw_setup(struct ep93xx_dma_chan *edmac)
+{
+ const struct ep93xx_dma_data *data = edmac->chan.private;
+ u32 control = 0;
+
+ if (!data) {
+ /* This is memcpy channel, nothing to configure */
+ writel(control, edmac->regs + M2M_CONTROL);
+ return 0;
+ }
+
+ switch (data->port) {
+ case EP93XX_DMA_SSP:
+ /*
+ * This was found via experimenting - anything less than 5
+ * causes the channel to perform only a partial transfer which
+ * leads to problems since we don't get DONE interrupt then.
+ */
+ control = (5 << M2M_CONTROL_PWSC_SHIFT);
+ control |= M2M_CONTROL_NO_HDSK;
+
+ if (data->direction == DMA_TO_DEVICE) {
+ control |= M2M_CONTROL_DAH;
+ control |= M2M_CONTROL_TM_TX;
+ control |= M2M_CONTROL_RSS_SSPTX;
+ } else {
+ control |= M2M_CONTROL_SAH;
+ control |= M2M_CONTROL_TM_RX;
+ control |= M2M_CONTROL_RSS_SSPRX;
+ }
+ break;
+
+ case EP93XX_DMA_IDE:
+ /*
+ * This IDE part is totally untested. Values below are taken
+ * from the EP93xx Users's Guide and might not be correct.
+ */
+ control |= M2M_CONTROL_NO_HDSK;
+ control |= M2M_CONTROL_RSS_IDE;
+ control |= M2M_CONTROL_PW_16;
+
+ if (data->direction == DMA_TO_DEVICE) {
+ /* Worst case from the UG */
+ control = (3 << M2M_CONTROL_PWSC_SHIFT);
+ control |= M2M_CONTROL_DAH;
+ control |= M2M_CONTROL_TM_TX;
+ } else {
+ control = (2 << M2M_CONTROL_PWSC_SHIFT);
+ control |= M2M_CONTROL_SAH;
+ control |= M2M_CONTROL_TM_RX;
+ }
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ writel(control, edmac->regs + M2M_CONTROL);
+ return 0;
+}
+
+static void m2m_hw_shutdown(struct ep93xx_dma_chan *edmac)
+{
+ /* Just disable the channel */
+ writel(0, edmac->regs + M2M_CONTROL);
+}
+
+static void m2m_fill_desc(struct ep93xx_dma_chan *edmac)
+{
+ struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac);
+
+ if (edmac->buffer == 0) {
+ writel(desc->src_addr, edmac->regs + M2M_SAR_BASE0);
+ writel(desc->dst_addr, edmac->regs + M2M_DAR_BASE0);
+ writel(desc->size, edmac->regs + M2M_BCR0);
+ } else {
+ writel(desc->src_addr, edmac->regs + M2M_SAR_BASE1);
+ writel(desc->dst_addr, edmac->regs + M2M_DAR_BASE1);
+ writel(desc->size, edmac->regs + M2M_BCR1);
+ }
+
+ edmac->buffer ^= 1;
+}
+
+static void m2m_hw_submit(struct ep93xx_dma_chan *edmac)
+{
+ struct ep93xx_dma_data *data = edmac->chan.private;
+ u32 control = readl(edmac->regs + M2M_CONTROL);
+
+ /*
+ * Since we allow clients to configure PW (peripheral width) we always
+ * clear PW bits here and then set them according what is given in
+ * the runtime configuration.
+ */
+ control &= ~M2M_CONTROL_PW_MASK;
+ control |= edmac->runtime_ctrl;
+
+ m2m_fill_desc(edmac);
+ control |= M2M_CONTROL_DONEINT;
+
+ /*
+ * Now we can finally enable the channel. For M2M channel this must be
+ * done _after_ the BCRx registers are programmed.
+ */
+ control |= M2M_CONTROL_ENABLE;
+ writel(control, edmac->regs + M2M_CONTROL);
+
+ if (!data) {
+ /*
+ * For memcpy channels the software trigger must be asserted
+ * in order to start the memcpy operation.
+ */
+ control |= M2M_CONTROL_START;
+ writel(control, edmac->regs + M2M_CONTROL);
+ }
+}
+
+static int m2m_hw_interrupt(struct ep93xx_dma_chan *edmac)
+{
+ u32 control;
+
+ if (!(readl(edmac->regs + M2M_INTERRUPT) & M2M_INTERRUPT_DONEINT))
+ return INTERRUPT_UNKNOWN;
+
+ /* Clear the DONE bit */
+ writel(0, edmac->regs + M2M_INTERRUPT);
+
+ /* Disable interrupts and the channel */
+ control = readl(edmac->regs + M2M_CONTROL);
+ control &= ~(M2M_CONTROL_DONEINT | M2M_CONTROL_ENABLE);
+ writel(control, edmac->regs + M2M_CONTROL);
+
+ /*
+ * Since we only get DONE interrupt we have to find out ourselves
+ * whether there still is something to process. So we try to advance
+ * the chain an see whether it succeeds.
+ */
+ if (ep93xx_dma_advance_active(edmac)) {
+ edmac->edma->hw_submit(edmac);
+ return INTERRUPT_NEXT_BUFFER;
+ }
+
+ return INTERRUPT_DONE;
+}
+
+/*
+ * DMA engine API implementation
+ */
+
+static struct ep93xx_dma_desc *
+ep93xx_dma_desc_get(struct ep93xx_dma_chan *edmac)
+{
+ struct ep93xx_dma_desc *desc, *_desc;
+ struct ep93xx_dma_desc *ret = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&edmac->lock, flags);
+ list_for_each_entry_safe(desc, _desc, &edmac->free_list, node) {
+ if (async_tx_test_ack(&desc->txd)) {
+ list_del_init(&desc->node);
+
+ /* Re-initialize the descriptor */
+ desc->src_addr = 0;
+ desc->dst_addr = 0;
+ desc->size = 0;
+ desc->complete = false;
+ desc->txd.cookie = 0;
+ desc->txd.callback = NULL;
+ desc->txd.callback_param = NULL;
+
+ ret = desc;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&edmac->lock, flags);
+ return ret;
+}
+
+static void ep93xx_dma_desc_put(struct ep93xx_dma_chan *edmac,
+ struct ep93xx_dma_desc *desc)
+{
+ if (desc) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&edmac->lock, flags);
+ list_splice_init(&desc->tx_list, &edmac->free_list);
+ list_add(&desc->node, &edmac->free_list);
+ spin_unlock_irqrestore(&edmac->lock, flags);
+ }
+}
+
+/**
+ * ep93xx_dma_advance_work - start processing the next pending transaction
+ * @edmac: channel
+ *
+ * If we have pending transactions queued and we are currently idling, this
+ * function takes the next queued transaction from the @edmac->queue and
+ * pushes it to the hardware for execution.
+ */
+static void ep93xx_dma_advance_work(struct ep93xx_dma_chan *edmac)
+{
+ struct ep93xx_dma_desc *new;
+ unsigned long flags;
+
+ spin_lock_irqsave(&edmac->lock, flags);
+ if (!list_empty(&edmac->active) || list_empty(&edmac->queue)) {
+ spin_unlock_irqrestore(&edmac->lock, flags);
+ return;
+ }
+
+ /* Take the next descriptor from the pending queue */
+ new = list_first_entry(&edmac->queue, struct ep93xx_dma_desc, node);
+ list_del_init(&new->node);
+
+ ep93xx_dma_set_active(edmac, new);
+
+ /* Push it to the hardware */
+ edmac->edma->hw_submit(edmac);
+ spin_unlock_irqrestore(&edmac->lock, flags);
+}
+
+static void ep93xx_dma_unmap_buffers(struct ep93xx_dma_desc *desc)
+{
+ struct device *dev = desc->txd.chan->device->dev;
+
+ if (!(desc->txd.flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+ if (desc->txd.flags & DMA_COMPL_SRC_UNMAP_SINGLE)
+ dma_unmap_single(dev, desc->src_addr, desc->size,
+ DMA_TO_DEVICE);
+ else
+ dma_unmap_page(dev, desc->src_addr, desc->size,
+ DMA_TO_DEVICE);
+ }
+ if (!(desc->txd.flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+ if (desc->txd.flags & DMA_COMPL_DEST_UNMAP_SINGLE)
+ dma_unmap_single(dev, desc->dst_addr, desc->size,
+ DMA_FROM_DEVICE);
+ else
+ dma_unmap_page(dev, desc->dst_addr, desc->size,
+ DMA_FROM_DEVICE);
+ }
+}
+
+static void ep93xx_dma_tasklet(unsigned long data)
+{
+ struct ep93xx_dma_chan *edmac = (struct ep93xx_dma_chan *)data;
+ struct ep93xx_dma_desc *desc, *d;
+ dma_async_tx_callback callback;
+ void *callback_param;
+ LIST_HEAD(list);
+
+ spin_lock_irq(&edmac->lock);
+ desc = ep93xx_dma_get_active(edmac);
+ if (desc->complete) {
+ edmac->last_completed = desc->txd.cookie;
+ list_splice_init(&edmac->active, &list);
+ }
+ spin_unlock_irq(&edmac->lock);
+
+ /* Pick up the next descriptor from the queue */
+ ep93xx_dma_advance_work(edmac);
+
+ callback = desc->txd.callback;
+ callback_param = desc->txd.callback_param;
+
+ /* Now we can release all the chained descriptors */
+ list_for_each_entry_safe(desc, d, &list, node) {
+ /*
+ * For the memcpy channels the API requires us to unmap the
+ * buffers unless requested otherwise.
+ */
+ if (!edmac->chan.private)
+ ep93xx_dma_unmap_buffers(desc);
+
+ ep93xx_dma_desc_put(edmac, desc);
+ }
+
+ if (callback)
+ callback(callback_param);
+}
+
+static irqreturn_t ep93xx_dma_interrupt(int irq, void *dev_id)
+{
+ struct ep93xx_dma_chan *edmac = dev_id;
+ irqreturn_t ret = IRQ_HANDLED;
+
+ spin_lock(&edmac->lock);
+
+ switch (edmac->edma->hw_interrupt(edmac)) {
+ case INTERRUPT_DONE:
+ ep93xx_dma_get_active(edmac)->complete = true;
+ tasklet_schedule(&edmac->tasklet);
+ break;
+
+ case INTERRUPT_NEXT_BUFFER:
+ if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags))
+ tasklet_schedule(&edmac->tasklet);
+ break;
+
+ default:
+ dev_warn(chan2dev(edmac), "unknown interrupt!\n");
+ ret = IRQ_NONE;
+ break;
+ }
+
+ spin_unlock(&edmac->lock);
+ return ret;
+}
+
+/**
+ * ep93xx_dma_tx_submit - set the prepared descriptor(s) to be executed
+ * @tx: descriptor to be executed
+ *
+ * Function will execute given descriptor on the hardware or if the hardware
+ * is busy, queue the descriptor to be executed later on. Returns cookie which
+ * can be used to poll the status of the descriptor.
+ */
+static dma_cookie_t ep93xx_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(tx->chan);
+ struct ep93xx_dma_desc *desc;
+ dma_cookie_t cookie;
+ unsigned long flags;
+
+ spin_lock_irqsave(&edmac->lock, flags);
+
+ cookie = edmac->chan.cookie;
+
+ if (++cookie < 0)
+ cookie = 1;
+
+ desc = container_of(tx, struct ep93xx_dma_desc, txd);
+
+ edmac->chan.cookie = cookie;
+ desc->txd.cookie = cookie;
+
+ /*
+ * If nothing is currently prosessed, we push this descriptor
+ * directly to the hardware. Otherwise we put the descriptor
+ * to the pending queue.
+ */
+ if (list_empty(&edmac->active)) {
+ ep93xx_dma_set_active(edmac, desc);
+ edmac->edma->hw_submit(edmac);
+ } else {
+ list_add_tail(&desc->node, &edmac->queue);
+ }
+
+ spin_unlock_irqrestore(&edmac->lock, flags);
+ return cookie;
+}
+
+/**
+ * ep93xx_dma_alloc_chan_resources - allocate resources for the channel
+ * @chan: channel to allocate resources
+ *
+ * Function allocates necessary resources for the given DMA channel and
+ * returns number of allocated descriptors for the channel. Negative errno
+ * is returned in case of failure.
+ */
+static int ep93xx_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+ struct ep93xx_dma_data *data = chan->private;
+ const char *name = dma_chan_name(chan);
+ int ret, i;
+
+ /* Sanity check the channel parameters */
+ if (!edmac->edma->m2m) {
+ if (!data)
+ return -EINVAL;
+ if (data->port < EP93XX_DMA_I2S1 ||
+ data->port > EP93XX_DMA_IRDA)
+ return -EINVAL;
+ if (data->direction != ep93xx_dma_chan_direction(chan))
+ return -EINVAL;
+ } else {
+ if (data) {
+ switch (data->port) {
+ case EP93XX_DMA_SSP:
+ case EP93XX_DMA_IDE:
+ if (data->direction != DMA_TO_DEVICE &&
+ data->direction != DMA_FROM_DEVICE)
+ return -EINVAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+ }
+
+ if (data && data->name)
+ name = data->name;
+
+ ret = clk_enable(edmac->clk);
+ if (ret)
+ return ret;
+
+ ret = request_irq(edmac->irq, ep93xx_dma_interrupt, 0, name, edmac);
+ if (ret)
+ goto fail_clk_disable;
+
+ spin_lock_irq(&edmac->lock);
+ edmac->last_completed = 1;
+ edmac->chan.cookie = 1;
+ ret = edmac->edma->hw_setup(edmac);
+ spin_unlock_irq(&edmac->lock);
+
+ if (ret)
+ goto fail_free_irq;
+
+ for (i = 0; i < DMA_MAX_CHAN_DESCRIPTORS; i++) {
+ struct ep93xx_dma_desc *desc;
+
+ desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+ if (!desc) {
+ dev_warn(chan2dev(edmac), "not enough descriptors\n");
+ break;
+ }
+
+ INIT_LIST_HEAD(&desc->tx_list);
+
+ dma_async_tx_descriptor_init(&desc->txd, chan);
+ desc->txd.flags = DMA_CTRL_ACK;
+ desc->txd.tx_submit = ep93xx_dma_tx_submit;
+
+ ep93xx_dma_desc_put(edmac, desc);
+ }
+
+ return i;
+
+fail_free_irq:
+ free_irq(edmac->irq, edmac);
+fail_clk_disable:
+ clk_disable(edmac->clk);
+
+ return ret;
+}
+
+/**
+ * ep93xx_dma_free_chan_resources - release resources for the channel
+ * @chan: channel
+ *
+ * Function releases all the resources allocated for the given channel.
+ * The channel must be idle when this is called.
+ */
+static void ep93xx_dma_free_chan_resources(struct dma_chan *chan)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+ struct ep93xx_dma_desc *desc, *d;
+ unsigned long flags;
+ LIST_HEAD(list);
+
+ BUG_ON(!list_empty(&edmac->active));
+ BUG_ON(!list_empty(&edmac->queue));
+
+ spin_lock_irqsave(&edmac->lock, flags);
+ edmac->edma->hw_shutdown(edmac);
+ edmac->runtime_addr = 0;
+ edmac->runtime_ctrl = 0;
+ edmac->buffer = 0;
+ list_splice_init(&edmac->free_list, &list);
+ spin_unlock_irqrestore(&edmac->lock, flags);
+
+ list_for_each_entry_safe(desc, d, &list, node)
+ kfree(desc);
+
+ clk_disable(edmac->clk);
+ free_irq(edmac->irq, edmac);
+}
+
+/**
+ * ep93xx_dma_prep_dma_memcpy - prepare a memcpy DMA operation
+ * @chan: channel
+ * @dest: destination bus address
+ * @src: source bus address
+ * @len: size of the transaction
+ * @flags: flags for the descriptor
+ *
+ * Returns a valid DMA descriptor or %NULL in case of failure.
+ */
+struct dma_async_tx_descriptor *
+ep93xx_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
+ dma_addr_t src, size_t len, unsigned long flags)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+ struct ep93xx_dma_desc *desc, *first;
+ size_t bytes, offset;
+
+ first = NULL;
+ for (offset = 0; offset < len; offset += bytes) {
+ desc = ep93xx_dma_desc_get(edmac);
+ if (!desc) {
+ dev_warn(chan2dev(edmac), "couln't get descriptor\n");
+ goto fail;
+ }
+
+ bytes = min_t(size_t, len - offset, DMA_MAX_CHAN_BYTES);
+
+ desc->src_addr = src + offset;
+ desc->dst_addr = dest + offset;
+ desc->size = bytes;
+
+ if (!first)
+ first = desc;
+ else
+ list_add_tail(&desc->node, &first->tx_list);
+ }
+
+ first->txd.cookie = -EBUSY;
+ first->txd.flags = flags;
+
+ return &first->txd;
+fail:
+ ep93xx_dma_desc_put(edmac, first);
+ return NULL;
+}
+
+/**
+ * ep93xx_dma_prep_slave_sg - prepare a slave DMA operation
+ * @chan: channel
+ * @sgl: list of buffers to transfer
+ * @sg_len: number of entries in @sgl
+ * @dir: direction of tha DMA transfer
+ * @flags: flags for the descriptor
+ *
+ * Returns a valid DMA descriptor or %NULL in case of failure.
+ */
+static struct dma_async_tx_descriptor *
+ep93xx_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_data_direction dir,
+ unsigned long flags)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+ struct ep93xx_dma_desc *desc, *first;
+ struct scatterlist *sg;
+ int i;
+
+ if (!edmac->edma->m2m && dir != ep93xx_dma_chan_direction(chan)) {
+ dev_warn(chan2dev(edmac),
+ "channel was configured with different direction\n");
+ return NULL;
+ }
+
+ if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags)) {
+ dev_warn(chan2dev(edmac),
+ "channel is already used for cyclic transfers\n");
+ return NULL;
+ }
+
+ first = NULL;
+ for_each_sg(sgl, sg, sg_len, i) {
+ size_t sg_len = sg_dma_len(sg);
+
+ if (sg_len > DMA_MAX_CHAN_BYTES) {
+ dev_warn(chan2dev(edmac), "too big transfer size %d\n",
+ sg_len);
+ goto fail;
+ }
+
+ desc = ep93xx_dma_desc_get(edmac);
+ if (!desc) {
+ dev_warn(chan2dev(edmac), "couln't get descriptor\n");
+ goto fail;
+ }
+
+ if (dir == DMA_TO_DEVICE) {
+ desc->src_addr = sg_dma_address(sg);
+ desc->dst_addr = edmac->runtime_addr;
+ } else {
+ desc->src_addr = edmac->runtime_addr;
+ desc->dst_addr = sg_dma_address(sg);
+ }
+ desc->size = sg_len;
+
+ if (!first)
+ first = desc;
+ else
+ list_add_tail(&desc->node, &first->tx_list);
+ }
+
+ first->txd.cookie = -EBUSY;
+ first->txd.flags = flags;
+
+ return &first->txd;
+
+fail:
+ ep93xx_dma_desc_put(edmac, first);
+ return NULL;
+}
+
+/**
+ * ep93xx_dma_prep_dma_cyclic - prepare a cyclic DMA operation
+ * @chan: channel
+ * @dma_addr: DMA mapped address of the buffer
+ * @buf_len: length of the buffer (in bytes)
+ * @period_len: lenght of a single period
+ * @dir: direction of the operation
+ *
+ * Prepares a descriptor for cyclic DMA operation. This means that once the
+ * descriptor is submitted, we will be submitting in a @period_len sized
+ * buffers and calling callback once the period has been elapsed. Transfer
+ * terminates only when client calls dmaengine_terminate_all() for this
+ * channel.
+ *
+ * Returns a valid DMA descriptor or %NULL in case of failure.
+ */
+static struct dma_async_tx_descriptor *
+ep93xx_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr,
+ size_t buf_len, size_t period_len,
+ enum dma_data_direction dir)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+ struct ep93xx_dma_desc *desc, *first;
+ size_t offset = 0;
+
+ if (!edmac->edma->m2m && dir != ep93xx_dma_chan_direction(chan)) {
+ dev_warn(chan2dev(edmac),
+ "channel was configured with different direction\n");
+ return NULL;
+ }
+
+ if (test_and_set_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags)) {
+ dev_warn(chan2dev(edmac),
+ "channel is already used for cyclic transfers\n");
+ return NULL;
+ }
+
+ if (period_len > DMA_MAX_CHAN_BYTES) {
+ dev_warn(chan2dev(edmac), "too big period length %d\n",
+ period_len);
+ return NULL;
+ }
+
+ /* Split the buffer into period size chunks */
+ first = NULL;
+ for (offset = 0; offset < buf_len; offset += period_len) {
+ desc = ep93xx_dma_desc_get(edmac);
+ if (!desc) {
+ dev_warn(chan2dev(edmac), "couln't get descriptor\n");
+ goto fail;
+ }
+
+ if (dir == DMA_TO_DEVICE) {
+ desc->src_addr = dma_addr + offset;
+ desc->dst_addr = edmac->runtime_addr;
+ } else {
+ desc->src_addr = edmac->runtime_addr;
+ desc->dst_addr = dma_addr + offset;
+ }
+
+ desc->size = period_len;
+
+ if (!first)
+ first = desc;
+ else
+ list_add_tail(&desc->node, &first->tx_list);
+ }
+
+ first->txd.cookie = -EBUSY;
+
+ return &first->txd;
+
+fail:
+ ep93xx_dma_desc_put(edmac, first);
+ return NULL;
+}
+
+/**
+ * ep93xx_dma_terminate_all - terminate all transactions
+ * @edmac: channel
+ *
+ * Stops all DMA transactions. All descriptors are put back to the
+ * @edmac->free_list and callbacks are _not_ called.
+ */
+static int ep93xx_dma_terminate_all(struct ep93xx_dma_chan *edmac)
+{
+ struct ep93xx_dma_desc *desc, *_d;
+ unsigned long flags;
+ LIST_HEAD(list);
+
+ spin_lock_irqsave(&edmac->lock, flags);
+ /* First we disable and flush the DMA channel */
+ edmac->edma->hw_shutdown(edmac);
+ clear_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags);
+ list_splice_init(&edmac->active, &list);
+ list_splice_init(&edmac->queue, &list);
+ /*
+ * We then re-enable the channel. This way we can continue submitting
+ * the descriptors by just calling ->hw_submit() again.
+ */
+ edmac->edma->hw_setup(edmac);
+ spin_unlock_irqrestore(&edmac->lock, flags);
+
+ list_for_each_entry_safe(desc, _d, &list, node)
+ ep93xx_dma_desc_put(edmac, desc);
+
+ return 0;
+}
+
+static int ep93xx_dma_slave_config(struct ep93xx_dma_chan *edmac,
+ struct dma_slave_config *config)
+{
+ enum dma_slave_buswidth width;
+ unsigned long flags;
+ u32 addr, ctrl;
+
+ if (!edmac->edma->m2m)
+ return -EINVAL;
+
+ switch (config->direction) {
+ case DMA_FROM_DEVICE:
+ width = config->src_addr_width;
+ addr = config->src_addr;
+ break;
+
+ case DMA_TO_DEVICE:
+ width = config->dst_addr_width;
+ addr = config->dst_addr;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ switch (width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ ctrl = 0;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ ctrl = M2M_CONTROL_PW_16;
+ break;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ ctrl = M2M_CONTROL_PW_32;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&edmac->lock, flags);
+ edmac->runtime_addr = addr;
+ edmac->runtime_ctrl = ctrl;
+ spin_unlock_irqrestore(&edmac->lock, flags);
+
+ return 0;
+}
+
+/**
+ * ep93xx_dma_control - manipulate all pending operations on a channel
+ * @chan: channel
+ * @cmd: control command to perform
+ * @arg: optional argument
+ *
+ * Controls the channel. Function returns %0 in case of success or negative
+ * error in case of failure.
+ */
+static int ep93xx_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+ struct dma_slave_config *config;
+
+ switch (cmd) {
+ case DMA_TERMINATE_ALL:
+ return ep93xx_dma_terminate_all(edmac);
+
+ case DMA_SLAVE_CONFIG:
+ config = (struct dma_slave_config *)arg;
+ return ep93xx_dma_slave_config(edmac, config);
+
+ default:
+ break;
+ }
+
+ return -ENOSYS;
+}
+
+/**
+ * ep93xx_dma_tx_status - check if a transaction is completed
+ * @chan: channel
+ * @cookie: transaction specific cookie
+ * @state: state of the transaction is stored here if given
+ *
+ * This function can be used to query state of a given transaction.
+ */
+static enum dma_status ep93xx_dma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *state)
+{
+ struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
+ dma_cookie_t last_used, last_completed;
+ enum dma_status ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&edmac->lock, flags);
+ last_used = chan->cookie;
+ last_completed = edmac->last_completed;
+ spin_unlock_irqrestore(&edmac->lock, flags);
+
+ ret = dma_async_is_complete(cookie, last_completed, last_used);
+ dma_set_tx_state(state, last_completed, last_used, 0);
+
+ return ret;
+}
+
+/**
+ * ep93xx_dma_issue_pending - push pending transactions to the hardware
+ * @chan: channel
+ *
+ * When this function is called, all pending transactions are pushed to the
+ * hardware and executed.
+ */
+static void ep93xx_dma_issue_pending(struct dma_chan *chan)
+{
+ ep93xx_dma_advance_work(to_ep93xx_dma_chan(chan));
+}
+
+static int __init ep93xx_dma_probe(struct platform_device *pdev)
+{
+ struct ep93xx_dma_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct ep93xx_dma_engine *edma;
+ struct dma_device *dma_dev;
+ size_t edma_size;
+ int ret, i;
+
+ edma_size = pdata->num_channels * sizeof(struct ep93xx_dma_chan);
+ edma = kzalloc(sizeof(*edma) + edma_size, GFP_KERNEL);
+ if (!edma)
+ return -ENOMEM;
+
+ dma_dev = &edma->dma_dev;
+ edma->m2m = platform_get_device_id(pdev)->driver_data;
+ edma->num_channels = pdata->num_channels;
+
+ INIT_LIST_HEAD(&dma_dev->channels);
+ for (i = 0; i < pdata->num_channels; i++) {
+ const struct ep93xx_dma_chan_data *cdata = &pdata->channels[i];
+ struct ep93xx_dma_chan *edmac = &edma->channels[i];
+
+ edmac->chan.device = dma_dev;
+ edmac->regs = cdata->base;
+ edmac->irq = cdata->irq;
+ edmac->edma = edma;
+
+ edmac->clk = clk_get(NULL, cdata->name);
+ if (IS_ERR(edmac->clk)) {
+ dev_warn(&pdev->dev, "failed to get clock for %s\n",
+ cdata->name);
+ continue;
+ }
+
+ spin_lock_init(&edmac->lock);
+ INIT_LIST_HEAD(&edmac->active);
+ INIT_LIST_HEAD(&edmac->queue);
+ INIT_LIST_HEAD(&edmac->free_list);
+ tasklet_init(&edmac->tasklet, ep93xx_dma_tasklet,
+ (unsigned long)edmac);
+
+ list_add_tail(&edmac->chan.device_node,
+ &dma_dev->channels);
+ }
+
+ dma_cap_zero(dma_dev->cap_mask);
+ dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
+ dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
+
+ dma_dev->dev = &pdev->dev;
+ dma_dev->device_alloc_chan_resources = ep93xx_dma_alloc_chan_resources;
+ dma_dev->device_free_chan_resources = ep93xx_dma_free_chan_resources;
+ dma_dev->device_prep_slave_sg = ep93xx_dma_prep_slave_sg;
+ dma_dev->device_prep_dma_cyclic = ep93xx_dma_prep_dma_cyclic;
+ dma_dev->device_control = ep93xx_dma_control;
+ dma_dev->device_issue_pending = ep93xx_dma_issue_pending;
+ dma_dev->device_tx_status = ep93xx_dma_tx_status;
+
+ dma_set_max_seg_size(dma_dev->dev, DMA_MAX_CHAN_BYTES);
+
+ if (edma->m2m) {
+ dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+ dma_dev->device_prep_dma_memcpy = ep93xx_dma_prep_dma_memcpy;
+
+ edma->hw_setup = m2m_hw_setup;
+ edma->hw_shutdown = m2m_hw_shutdown;
+ edma->hw_submit = m2m_hw_submit;
+ edma->hw_interrupt = m2m_hw_interrupt;
+ } else {
+ dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
+
+ edma->hw_setup = m2p_hw_setup;
+ edma->hw_shutdown = m2p_hw_shutdown;
+ edma->hw_submit = m2p_hw_submit;
+ edma->hw_interrupt = m2p_hw_interrupt;
+ }
+
+ ret = dma_async_device_register(dma_dev);
+ if (unlikely(ret)) {
+ for (i = 0; i < edma->num_channels; i++) {
+ struct ep93xx_dma_chan *edmac = &edma->channels[i];
+ if (!IS_ERR_OR_NULL(edmac->clk))
+ clk_put(edmac->clk);
+ }
+ kfree(edma);
+ } else {
+ dev_info(dma_dev->dev, "EP93xx M2%s DMA ready\n",
+ edma->m2m ? "M" : "P");
+ }
+
+ return ret;
+}
+
+static struct platform_device_id ep93xx_dma_driver_ids[] = {
+ { "ep93xx-dma-m2p", 0 },
+ { "ep93xx-dma-m2m", 1 },
+ { },
+};
+
+static struct platform_driver ep93xx_dma_driver = {
+ .driver = {
+ .name = "ep93xx-dma",
+ },
+ .id_table = ep93xx_dma_driver_ids,
+};
+
+static int __init ep93xx_dma_module_init(void)
+{
+ return platform_driver_probe(&ep93xx_dma_driver, ep93xx_dma_probe);
+}
+subsys_initcall(ep93xx_dma_module_init);
+
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
+MODULE_DESCRIPTION("EP93xx DMA driver");
+MODULE_LICENSE("GPL");
git.openpandora.org / pandora-kernel.git / commitdiff