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authorYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>2015-04-01 15:22:45 +0900
committerVinod Koul <vinod.koul@intel.com>2015-04-02 12:57:32 +0530
commit0c1c8ff32fa29e425b4938934c21afdb81104431 (patch)
treefaf7202a17ebabad17fa449c6e300d93808af1ce /drivers/dma/sh/usb-dmac.c
parenta7267831565030ab94dab76eb1afe5d4b63a1009 (diff)
dmaengine: usb-dmac: Add Renesas USB DMA Controller (USB-DMAC) driver
This DMAC is Renesas USB high-speed module DMA controller that supports slave transfer. This USB-DMAC has similar register sets with R-Car Gen2 DMAC, but the USB-DMAC has specific registers to control the USB transactions. If this code is added into the rcar-dmac driver, it will become unreadable. So, this driver is independent from the rcar-dmac. And, this USB-DMAC uses virt-dma infrastructure. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/sh/usb-dmac.c')
-rw-r--r--drivers/dma/sh/usb-dmac.c910
1 files changed, 910 insertions, 0 deletions
diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
new file mode 100644
index 000000000000..d5dad98bef0b
--- /dev/null
+++ b/drivers/dma/sh/usb-dmac.c
@@ -0,0 +1,910 @@
+/*
+ * Renesas USB DMA Controller Driver
+ *
+ * Copyright (C) 2015 Renesas Electronics Corporation
+ *
+ * based on rcar-dmac.c
+ * Copyright (C) 2014 Renesas Electronics Inc.
+ * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "../dmaengine.h"
+#include "../virt-dma.h"
+
+/*
+ * struct usb_dmac_sg - Descriptor for a hardware transfer
+ * @mem_addr: memory address
+ * @size: transfer size in bytes
+ */
+struct usb_dmac_sg {
+ dma_addr_t mem_addr;
+ u32 size;
+};
+
+/*
+ * struct usb_dmac_desc - USB DMA Transfer Descriptor
+ * @vd: base virtual channel DMA transaction descriptor
+ * @direction: direction of the DMA transfer
+ * @sg_allocated_len: length of allocated sg
+ * @sg_len: length of sg
+ * @sg_index: index of sg
+ * @residue: residue after the DMAC completed a transfer
+ * @node: node for desc_got and desc_freed
+ * @done_cookie: cookie after the DMAC completed a transfer
+ * @sg: information for the transfer
+ */
+struct usb_dmac_desc {
+ struct virt_dma_desc vd;
+ enum dma_transfer_direction direction;
+ unsigned int sg_allocated_len;
+ unsigned int sg_len;
+ unsigned int sg_index;
+ u32 residue;
+ struct list_head node;
+ dma_cookie_t done_cookie;
+ struct usb_dmac_sg sg[0];
+};
+
+#define to_usb_dmac_desc(vd) container_of(vd, struct usb_dmac_desc, vd)
+
+/*
+ * struct usb_dmac_chan - USB DMA Controller Channel
+ * @vc: base virtual DMA channel object
+ * @iomem: channel I/O memory base
+ * @index: index of this channel in the controller
+ * @irq: irq number of this channel
+ * @desc: the current descriptor
+ * @descs_allocated: number of descriptors allocated
+ * @desc_got: got descriptors
+ * @desc_freed: freed descriptors after the DMAC completed a transfer
+ */
+struct usb_dmac_chan {
+ struct virt_dma_chan vc;
+ void __iomem *iomem;
+ unsigned int index;
+ int irq;
+ struct usb_dmac_desc *desc;
+ int descs_allocated;
+ struct list_head desc_got;
+ struct list_head desc_freed;
+};
+
+#define to_usb_dmac_chan(c) container_of(c, struct usb_dmac_chan, vc.chan)
+
+/*
+ * struct usb_dmac - USB DMA Controller
+ * @engine: base DMA engine object
+ * @dev: the hardware device
+ * @iomem: remapped I/O memory base
+ * @n_channels: number of available channels
+ * @channels: array of DMAC channels
+ */
+struct usb_dmac {
+ struct dma_device engine;
+ struct device *dev;
+ void __iomem *iomem;
+
+ unsigned int n_channels;
+ struct usb_dmac_chan *channels;
+};
+
+#define to_usb_dmac(d) container_of(d, struct usb_dmac, engine)
+
+/* -----------------------------------------------------------------------------
+ * Registers
+ */
+
+#define USB_DMAC_CHAN_OFFSET(i) (0x20 + 0x20 * (i))
+
+#define USB_DMASWR 0x0008
+#define USB_DMASWR_SWR (1 << 0)
+#define USB_DMAOR 0x0060
+#define USB_DMAOR_AE (1 << 2)
+#define USB_DMAOR_DME (1 << 0)
+
+#define USB_DMASAR 0x0000
+#define USB_DMADAR 0x0004
+#define USB_DMATCR 0x0008
+#define USB_DMATCR_MASK 0x00ffffff
+#define USB_DMACHCR 0x0014
+#define USB_DMACHCR_FTE (1 << 24)
+#define USB_DMACHCR_NULLE (1 << 16)
+#define USB_DMACHCR_NULL (1 << 12)
+#define USB_DMACHCR_TS_8B ((0 << 7) | (0 << 6))
+#define USB_DMACHCR_TS_16B ((0 << 7) | (1 << 6))
+#define USB_DMACHCR_TS_32B ((1 << 7) | (0 << 6))
+#define USB_DMACHCR_IE (1 << 5)
+#define USB_DMACHCR_SP (1 << 2)
+#define USB_DMACHCR_TE (1 << 1)
+#define USB_DMACHCR_DE (1 << 0)
+#define USB_DMATEND 0x0018
+
+/* Hardcode the xfer_shift to 5 (32bytes) */
+#define USB_DMAC_XFER_SHIFT 5
+#define USB_DMAC_XFER_SIZE (1 << USB_DMAC_XFER_SHIFT)
+#define USB_DMAC_CHCR_TS USB_DMACHCR_TS_32B
+#define USB_DMAC_SLAVE_BUSWIDTH DMA_SLAVE_BUSWIDTH_32_BYTES
+
+/* for descriptors */
+#define USB_DMAC_INITIAL_NR_DESC 16
+#define USB_DMAC_INITIAL_NR_SG 8
+
+/* -----------------------------------------------------------------------------
+ * Device access
+ */
+
+static void usb_dmac_write(struct usb_dmac *dmac, u32 reg, u32 data)
+{
+ writel(data, dmac->iomem + reg);
+}
+
+static u32 usb_dmac_read(struct usb_dmac *dmac, u32 reg)
+{
+ return readl(dmac->iomem + reg);
+}
+
+static u32 usb_dmac_chan_read(struct usb_dmac_chan *chan, u32 reg)
+{
+ return readl(chan->iomem + reg);
+}
+
+static void usb_dmac_chan_write(struct usb_dmac_chan *chan, u32 reg, u32 data)
+{
+ writel(data, chan->iomem + reg);
+}
+
+/* -----------------------------------------------------------------------------
+ * Initialization and configuration
+ */
+
+static bool usb_dmac_chan_is_busy(struct usb_dmac_chan *chan)
+{
+ u32 chcr = usb_dmac_chan_read(chan, USB_DMACHCR);
+
+ return (chcr & (USB_DMACHCR_DE | USB_DMACHCR_TE)) == USB_DMACHCR_DE;
+}
+
+static u32 usb_dmac_calc_tend(u32 size)
+{
+ /*
+ * Please refer to the Figure "Example of Final Transaction Valid
+ * Data Transfer Enable (EDTEN) Setting" in the data sheet.
+ */
+ return 0xffffffff << (32 - (size % USB_DMAC_XFER_SIZE ? :
+ USB_DMAC_XFER_SIZE));
+}
+
+/* This function is already held by vc.lock */
+static void usb_dmac_chan_start_sg(struct usb_dmac_chan *chan,
+ unsigned int index)
+{
+ struct usb_dmac_desc *desc = chan->desc;
+ struct usb_dmac_sg *sg = desc->sg + index;
+ dma_addr_t src_addr = 0, dst_addr = 0;
+
+ WARN_ON_ONCE(usb_dmac_chan_is_busy(chan));
+
+ if (desc->direction == DMA_DEV_TO_MEM)
+ dst_addr = sg->mem_addr;
+ else
+ src_addr = sg->mem_addr;
+
+ dev_dbg(chan->vc.chan.device->dev,
+ "chan%u: queue sg %p: %u@%pad -> %pad\n",
+ chan->index, sg, sg->size, &src_addr, &dst_addr);
+
+ usb_dmac_chan_write(chan, USB_DMASAR, src_addr & 0xffffffff);
+ usb_dmac_chan_write(chan, USB_DMADAR, dst_addr & 0xffffffff);
+ usb_dmac_chan_write(chan, USB_DMATCR,
+ DIV_ROUND_UP(sg->size, USB_DMAC_XFER_SIZE));
+ usb_dmac_chan_write(chan, USB_DMATEND, usb_dmac_calc_tend(sg->size));
+
+ usb_dmac_chan_write(chan, USB_DMACHCR, USB_DMAC_CHCR_TS |
+ USB_DMACHCR_NULLE | USB_DMACHCR_IE | USB_DMACHCR_DE);
+}
+
+/* This function is already held by vc.lock */
+static void usb_dmac_chan_start_desc(struct usb_dmac_chan *chan)
+{
+ struct virt_dma_desc *vd;
+
+ vd = vchan_next_desc(&chan->vc);
+ if (!vd) {
+ chan->desc = NULL;
+ return;
+ }
+
+ /*
+ * Remove this request from vc->desc_issued. Otherwise, this driver
+ * will get the previous value from vchan_next_desc() after a transfer
+ * was completed.
+ */
+ list_del(&vd->node);
+
+ chan->desc = to_usb_dmac_desc(vd);
+ chan->desc->sg_index = 0;
+ usb_dmac_chan_start_sg(chan, 0);
+}
+
+static int usb_dmac_init(struct usb_dmac *dmac)
+{
+ u16 dmaor;
+
+ /* Clear all channels and enable the DMAC globally. */
+ usb_dmac_write(dmac, USB_DMAOR, USB_DMAOR_DME);
+
+ dmaor = usb_dmac_read(dmac, USB_DMAOR);
+ if ((dmaor & (USB_DMAOR_AE | USB_DMAOR_DME)) != USB_DMAOR_DME) {
+ dev_warn(dmac->dev, "DMAOR initialization failed.\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * Descriptors allocation and free
+ */
+static int usb_dmac_desc_alloc(struct usb_dmac_chan *chan, unsigned int sg_len,
+ gfp_t gfp)
+{
+ struct usb_dmac_desc *desc;
+ unsigned long flags;
+
+ desc = kzalloc(sizeof(*desc) + sg_len * sizeof(desc->sg[0]), gfp);
+ if (!desc)
+ return -ENOMEM;
+
+ desc->sg_allocated_len = sg_len;
+ INIT_LIST_HEAD(&desc->node);
+
+ spin_lock_irqsave(&chan->vc.lock, flags);
+ list_add_tail(&desc->node, &chan->desc_freed);
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+ return 0;
+}
+
+static void usb_dmac_desc_free(struct usb_dmac_chan *chan)
+{
+ struct usb_dmac_desc *desc;
+ LIST_HEAD(list);
+
+ list_splice_init(&chan->desc_freed, &list);
+ list_splice_init(&chan->desc_got, &list);
+
+ list_for_each_entry(desc, &list, node) {
+ list_del(&desc->node);
+ kfree(desc);
+ }
+ chan->descs_allocated = 0;
+}
+
+static struct usb_dmac_desc *usb_dmac_desc_get(struct usb_dmac_chan *chan,
+ unsigned int sg_len, gfp_t gfp)
+{
+ struct usb_dmac_desc *desc = NULL;
+ unsigned long flags;
+
+ /* Get a freed descritpor */
+ spin_lock_irqsave(&chan->vc.lock, flags);
+ list_for_each_entry(desc, &chan->desc_freed, node) {
+ if (sg_len <= desc->sg_allocated_len) {
+ list_move_tail(&desc->node, &chan->desc_got);
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+ return desc;
+ }
+ }
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+ /* Allocate a new descriptor */
+ if (!usb_dmac_desc_alloc(chan, sg_len, gfp)) {
+ /* If allocated the desc, it was added to tail of the list */
+ spin_lock_irqsave(&chan->vc.lock, flags);
+ desc = list_last_entry(&chan->desc_freed, struct usb_dmac_desc,
+ node);
+ list_move_tail(&desc->node, &chan->desc_got);
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+ return desc;
+ }
+
+ return NULL;
+}
+
+static void usb_dmac_desc_put(struct usb_dmac_chan *chan,
+ struct usb_dmac_desc *desc)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->vc.lock, flags);
+ list_move_tail(&desc->node, &chan->desc_freed);
+ spin_unlock_irqrestore(&chan->vc.lock, flags);
+}
+
+/* -----------------------------------------------------------------------------
+ * Stop and reset
+ */
+
+static void usb_dmac_soft_reset(struct usb_dmac_chan *uchan)
+{
+ struct dma_chan *chan = &uchan->vc.chan;
+ struct usb_dmac *dmac = to_usb_dmac(chan->device);
+ int i;
+
+ /* Don't issue soft reset if any one of channels is busy */
+ for (i = 0; i < dmac->n_channels; ++i) {
+ if (usb_dmac_chan_is_busy(uchan))
+ return;
+ }
+
+ usb_dmac_write(dmac, USB_DMAOR, 0);
+ usb_dmac_write(dmac, USB_DMASWR, USB_DMASWR_SWR);
+ udelay(100);
+ usb_dmac_write(dmac, USB_DMASWR, 0);
+ usb_dmac_write(dmac, USB_DMAOR, 1);
+}
+
+static void usb_dmac_chan_halt(struct usb_dmac_chan *chan)
+{
+ u32 chcr = usb_dmac_chan_read(chan, USB_DMACHCR);
+
+ chcr &= ~(USB_DMACHCR_IE | USB_DMACHCR_TE | USB_DMACHCR_DE);
+ usb_dmac_chan_write(chan, USB_DMACHCR, chcr);
+
+ usb_dmac_soft_reset(chan);
+}
+
+static void usb_dmac_stop(struct usb_dmac *dmac)
+{
+ usb_dmac_write(dmac, USB_DMAOR, 0);
+}
+
+/* -----------------------------------------------------------------------------
+ * DMA engine operations
+ */
+
+static int usb_dmac_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
+ int ret;
+
+ while (uchan->descs_allocated < USB_DMAC_INITIAL_NR_DESC) {
+ ret = usb_dmac_desc_alloc(uchan, USB_DMAC_INITIAL_NR_SG,
+ GFP_KERNEL);
+ if (ret < 0) {
+ usb_dmac_desc_free(uchan);
+ return ret;
+ }
+ uchan->descs_allocated++;
+ }
+
+ return pm_runtime_get_sync(chan->device->dev);
+}
+
+static void usb_dmac_free_chan_resources(struct dma_chan *chan)
+{
+ struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
+ unsigned long flags;
+
+ /* Protect against ISR */
+ spin_lock_irqsave(&uchan->vc.lock, flags);
+ usb_dmac_chan_halt(uchan);
+ spin_unlock_irqrestore(&uchan->vc.lock, flags);
+
+ usb_dmac_desc_free(uchan);
+ vchan_free_chan_resources(&uchan->vc);
+
+ pm_runtime_put(chan->device->dev);
+}
+
+static struct dma_async_tx_descriptor *
+usb_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_transfer_direction dir,
+ unsigned long dma_flags, void *context)
+{
+ struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
+ struct usb_dmac_desc *desc;
+ struct scatterlist *sg;
+ int i;
+
+ if (!sg_len) {
+ dev_warn(chan->device->dev,
+ "%s: bad parameter: len=%d\n", __func__, sg_len);
+ return NULL;
+ }
+
+ desc = usb_dmac_desc_get(uchan, sg_len, GFP_NOWAIT);
+ if (!desc)
+ return NULL;
+
+ desc->direction = dir;
+ desc->sg_len = sg_len;
+ for_each_sg(sgl, sg, sg_len, i) {
+ desc->sg[i].mem_addr = sg_dma_address(sg);
+ desc->sg[i].size = sg_dma_len(sg);
+ }
+
+ return vchan_tx_prep(&uchan->vc, &desc->vd, dma_flags);
+}
+
+static int usb_dmac_chan_terminate_all(struct dma_chan *chan)
+{
+ struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
+ struct usb_dmac_desc *desc;
+ unsigned long flags;
+ LIST_HEAD(head);
+ LIST_HEAD(list);
+
+ spin_lock_irqsave(&uchan->vc.lock, flags);
+ usb_dmac_chan_halt(uchan);
+ vchan_get_all_descriptors(&uchan->vc, &head);
+ if (uchan->desc)
+ uchan->desc = NULL;
+ list_splice_init(&uchan->desc_got, &list);
+ list_for_each_entry(desc, &list, node)
+ list_move_tail(&desc->node, &uchan->desc_freed);
+ spin_unlock_irqrestore(&uchan->vc.lock, flags);
+ vchan_dma_desc_free_list(&uchan->vc, &head);
+
+ return 0;
+}
+
+static unsigned int usb_dmac_get_current_residue(struct usb_dmac_chan *chan,
+ struct usb_dmac_desc *desc,
+ int sg_index)
+{
+ struct usb_dmac_sg *sg = desc->sg + sg_index;
+ u32 mem_addr = sg->mem_addr & 0xffffffff;
+ unsigned int residue = sg->size;
+
+ /*
+ * We cannot use USB_DMATCR to calculate residue because USB_DMATCR
+ * has unsuited value to calculate.
+ */
+ if (desc->direction == DMA_DEV_TO_MEM)
+ residue -= usb_dmac_chan_read(chan, USB_DMADAR) - mem_addr;
+ else
+ residue -= usb_dmac_chan_read(chan, USB_DMASAR) - mem_addr;
+
+ return residue;
+}
+
+static u32 usb_dmac_chan_get_residue_if_complete(struct usb_dmac_chan *chan,
+ dma_cookie_t cookie)
+{
+ struct usb_dmac_desc *desc;
+ u32 residue = 0;
+
+ list_for_each_entry_reverse(desc, &chan->desc_freed, node) {
+ if (desc->done_cookie == cookie) {
+ residue = desc->residue;
+ break;
+ }
+ }
+
+ return residue;
+}
+
+static u32 usb_dmac_chan_get_residue(struct usb_dmac_chan *chan,
+ dma_cookie_t cookie)
+{
+ u32 residue = 0;
+ struct virt_dma_desc *vd;
+ struct usb_dmac_desc *desc = chan->desc;
+ int i;
+
+ if (!desc) {
+ vd = vchan_find_desc(&chan->vc, cookie);
+ if (!vd)
+ return 0;
+ desc = to_usb_dmac_desc(vd);
+ }
+
+ /* Compute the size of all usb_dmac_sg still to be transferred */
+ for (i = desc->sg_index + 1; i < desc->sg_len; i++)
+ residue += desc->sg[i].size;
+
+ /* Add the residue for the current sg */
+ residue += usb_dmac_get_current_residue(chan, desc, desc->sg_index);
+
+ return residue;
+}
+
+static enum dma_status usb_dmac_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
+ enum dma_status status;
+ unsigned int residue = 0;
+ unsigned long flags;
+
+ status = dma_cookie_status(chan, cookie, txstate);
+ /* a client driver will get residue after DMA_COMPLETE */
+ if (!txstate)
+ return status;
+
+ spin_lock_irqsave(&uchan->vc.lock, flags);
+ if (status == DMA_COMPLETE)
+ residue = usb_dmac_chan_get_residue_if_complete(uchan, cookie);
+ else
+ residue = usb_dmac_chan_get_residue(uchan, cookie);
+ spin_unlock_irqrestore(&uchan->vc.lock, flags);
+
+ dma_set_residue(txstate, residue);
+
+ return status;
+}
+
+static void usb_dmac_issue_pending(struct dma_chan *chan)
+{
+ struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&uchan->vc.lock, flags);
+ if (vchan_issue_pending(&uchan->vc) && !uchan->desc)
+ usb_dmac_chan_start_desc(uchan);
+ spin_unlock_irqrestore(&uchan->vc.lock, flags);
+}
+
+static void usb_dmac_virt_desc_free(struct virt_dma_desc *vd)
+{
+ struct usb_dmac_desc *desc = to_usb_dmac_desc(vd);
+ struct usb_dmac_chan *chan = to_usb_dmac_chan(vd->tx.chan);
+
+ usb_dmac_desc_put(chan, desc);
+}
+
+/* -----------------------------------------------------------------------------
+ * IRQ handling
+ */
+
+static void usb_dmac_isr_transfer_end(struct usb_dmac_chan *chan)
+{
+ struct usb_dmac_desc *desc = chan->desc;
+
+ BUG_ON(!desc);
+
+ if (++desc->sg_index < desc->sg_len) {
+ usb_dmac_chan_start_sg(chan, desc->sg_index);
+ } else {
+ desc->residue = usb_dmac_get_current_residue(chan, desc,
+ desc->sg_index - 1);
+ desc->done_cookie = desc->vd.tx.cookie;
+ vchan_cookie_complete(&desc->vd);
+
+ /* Restart the next transfer if this driver has a next desc */
+ usb_dmac_chan_start_desc(chan);
+ }
+}
+
+static irqreturn_t usb_dmac_isr_channel(int irq, void *dev)
+{
+ struct usb_dmac_chan *chan = dev;
+ irqreturn_t ret = IRQ_NONE;
+ u32 mask = USB_DMACHCR_TE;
+ u32 check_bits = USB_DMACHCR_TE | USB_DMACHCR_SP;
+ u32 chcr;
+
+ spin_lock(&chan->vc.lock);
+
+ chcr = usb_dmac_chan_read(chan, USB_DMACHCR);
+ if (chcr & check_bits)
+ mask |= USB_DMACHCR_DE | check_bits;
+ if (chcr & USB_DMACHCR_NULL) {
+ /* An interruption of TE will happen after we set FTE */
+ mask |= USB_DMACHCR_NULL;
+ chcr |= USB_DMACHCR_FTE;
+ ret |= IRQ_HANDLED;
+ }
+ usb_dmac_chan_write(chan, USB_DMACHCR, chcr & ~mask);
+
+ if (chcr & check_bits) {
+ usb_dmac_isr_transfer_end(chan);
+ ret |= IRQ_HANDLED;
+ }
+
+ spin_unlock(&chan->vc.lock);
+
+ return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * OF xlate and channel filter
+ */
+
+static bool usb_dmac_chan_filter(struct dma_chan *chan, void *arg)
+{
+ struct usb_dmac_chan *uchan = to_usb_dmac_chan(chan);
+ struct of_phandle_args *dma_spec = arg;
+
+ if (dma_spec->np != chan->device->dev->of_node)
+ return false;
+
+ /* USB-DMAC should be used with fixed usb controller's FIFO */
+ if (uchan->index != dma_spec->args[0])
+ return false;
+
+ return true;
+}
+
+static struct dma_chan *usb_dmac_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct usb_dmac_chan *uchan;
+ struct dma_chan *chan;
+ dma_cap_mask_t mask;
+
+ if (dma_spec->args_count != 1)
+ return NULL;
+
+ /* Only slave DMA channels can be allocated via DT */
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ chan = dma_request_channel(mask, usb_dmac_chan_filter, dma_spec);
+ if (!chan)
+ return NULL;
+
+ uchan = to_usb_dmac_chan(chan);
+
+ return chan;
+}
+
+/* -----------------------------------------------------------------------------
+ * Power management
+ */
+
+static int usb_dmac_runtime_suspend(struct device *dev)
+{
+ struct usb_dmac *dmac = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < dmac->n_channels; ++i)
+ usb_dmac_chan_halt(&dmac->channels[i]);
+
+ return 0;
+}
+
+static int usb_dmac_runtime_resume(struct device *dev)
+{
+ struct usb_dmac *dmac = dev_get_drvdata(dev);
+
+ return usb_dmac_init(dmac);
+}
+
+static const struct dev_pm_ops usb_dmac_pm = {
+ SET_RUNTIME_PM_OPS(usb_dmac_runtime_suspend, usb_dmac_runtime_resume,
+ NULL)
+};
+
+/* -----------------------------------------------------------------------------
+ * Probe and remove
+ */
+
+static int usb_dmac_chan_probe(struct usb_dmac *dmac,
+ struct usb_dmac_chan *uchan,
+ unsigned int index)
+{
+ struct platform_device *pdev = to_platform_device(dmac->dev);
+ char pdev_irqname[5];
+ char *irqname;
+ int ret;
+
+ uchan->index = index;
+ uchan->iomem = dmac->iomem + USB_DMAC_CHAN_OFFSET(index);
+
+ /* Request the channel interrupt. */
+ sprintf(pdev_irqname, "ch%u", index);
+ uchan->irq = platform_get_irq_byname(pdev, pdev_irqname);
+ if (uchan->irq < 0) {
+ dev_err(dmac->dev, "no IRQ specified for channel %u\n", index);
+ return -ENODEV;
+ }
+
+ irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u",
+ dev_name(dmac->dev), index);
+ if (!irqname)
+ return -ENOMEM;
+
+ ret = devm_request_irq(dmac->dev, uchan->irq, usb_dmac_isr_channel,
+ IRQF_SHARED, irqname, uchan);
+ if (ret) {
+ dev_err(dmac->dev, "failed to request IRQ %u (%d)\n",
+ uchan->irq, ret);
+ return ret;
+ }
+
+ uchan->vc.desc_free = usb_dmac_virt_desc_free;
+ vchan_init(&uchan->vc, &dmac->engine);
+ INIT_LIST_HEAD(&uchan->desc_freed);
+ INIT_LIST_HEAD(&uchan->desc_got);
+
+ return 0;
+}
+
+static int usb_dmac_parse_of(struct device *dev, struct usb_dmac *dmac)
+{
+ struct device_node *np = dev->of_node;
+ int ret;
+
+ ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels);
+ if (ret < 0) {
+ dev_err(dev, "unable to read dma-channels property\n");
+ return ret;
+ }
+
+ if (dmac->n_channels <= 0 || dmac->n_channels >= 100) {
+ dev_err(dev, "invalid number of channels %u\n",
+ dmac->n_channels);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int usb_dmac_probe(struct platform_device *pdev)
+{
+ const enum dma_slave_buswidth widths = USB_DMAC_SLAVE_BUSWIDTH;
+ struct dma_device *engine;
+ struct usb_dmac *dmac;
+ struct resource *mem;
+ unsigned int i;
+ int ret;
+
+ dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
+ if (!dmac)
+ return -ENOMEM;
+
+ dmac->dev = &pdev->dev;
+ platform_set_drvdata(pdev, dmac);
+
+ ret = usb_dmac_parse_of(&pdev->dev, dmac);
+ if (ret < 0)
+ return ret;
+
+ dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
+ sizeof(*dmac->channels), GFP_KERNEL);
+ if (!dmac->channels)
+ return -ENOMEM;
+
+ /* Request resources. */
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dmac->iomem = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(dmac->iomem))
+ return PTR_ERR(dmac->iomem);
+
+ /* Enable runtime PM and initialize the device. */
+ pm_runtime_enable(&pdev->dev);
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret);
+ return ret;
+ }
+
+ ret = usb_dmac_init(dmac);
+ pm_runtime_put(&pdev->dev);
+
+ if (ret) {
+ dev_err(&pdev->dev, "failed to reset device\n");
+ goto error;
+ }
+
+ /* Initialize the channels. */
+ INIT_LIST_HEAD(&dmac->engine.channels);
+
+ for (i = 0; i < dmac->n_channels; ++i) {
+ ret = usb_dmac_chan_probe(dmac, &dmac->channels[i], i);
+ if (ret < 0)
+ goto error;
+ }
+
+ /* Register the DMAC as a DMA provider for DT. */
+ ret = of_dma_controller_register(pdev->dev.of_node, usb_dmac_of_xlate,
+ NULL);
+ if (ret < 0)
+ goto error;
+
+ /*
+ * Register the DMA engine device.
+ *
+ * Default transfer size of 32 bytes requires 32-byte alignment.
+ */
+ engine = &dmac->engine;
+ dma_cap_set(DMA_SLAVE, engine->cap_mask);
+
+ engine->dev = &pdev->dev;
+
+ engine->src_addr_widths = widths;
+ engine->dst_addr_widths = widths;
+ engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
+ engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+
+ engine->device_alloc_chan_resources = usb_dmac_alloc_chan_resources;
+ engine->device_free_chan_resources = usb_dmac_free_chan_resources;
+ engine->device_prep_slave_sg = usb_dmac_prep_slave_sg;
+ engine->device_terminate_all = usb_dmac_chan_terminate_all;
+ engine->device_tx_status = usb_dmac_tx_status;
+ engine->device_issue_pending = usb_dmac_issue_pending;
+
+ ret = dma_async_device_register(engine);
+ if (ret < 0)
+ goto error;
+
+ return 0;
+
+error:
+ of_dma_controller_free(pdev->dev.of_node);
+ pm_runtime_disable(&pdev->dev);
+ return ret;
+}
+
+static void usb_dmac_chan_remove(struct usb_dmac *dmac,
+ struct usb_dmac_chan *uchan)
+{
+ usb_dmac_chan_halt(uchan);
+ devm_free_irq(dmac->dev, uchan->irq, uchan);
+}
+
+static int usb_dmac_remove(struct platform_device *pdev)
+{
+ struct usb_dmac *dmac = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < dmac->n_channels; ++i)
+ usb_dmac_chan_remove(dmac, &dmac->channels[i]);
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&dmac->engine);
+
+ pm_runtime_disable(&pdev->dev);
+
+ return 0;
+}
+
+static void usb_dmac_shutdown(struct platform_device *pdev)
+{
+ struct usb_dmac *dmac = platform_get_drvdata(pdev);
+
+ usb_dmac_stop(dmac);
+}
+
+static const struct of_device_id usb_dmac_of_ids[] = {
+ { .compatible = "renesas,usb-dmac", },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, usb_dmac_of_ids);
+
+static struct platform_driver usb_dmac_driver = {
+ .driver = {
+ .pm = &usb_dmac_pm,
+ .name = "usb-dmac",
+ .of_match_table = usb_dmac_of_ids,
+ },
+ .probe = usb_dmac_probe,
+ .remove = usb_dmac_remove,
+ .shutdown = usb_dmac_shutdown,
+};
+
+module_platform_driver(usb_dmac_driver);
+
+MODULE_DESCRIPTION("Renesas USB DMA Controller Driver");
+MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");
+MODULE_LICENSE("GPL v2");

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