diff options
Diffstat (limited to 'drivers/dma/sh/usb-dmac.c')
| -rw-r--r-- | drivers/dma/sh/usb-dmac.c | 910 |
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..f705798ce3eb --- /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, *_desc; + LIST_HEAD(list); + + list_splice_init(&chan->desc_freed, &list); + list_splice_init(&chan->desc_got, &list); + + list_for_each_entry_safe(desc, _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"); |