linux-stable/drivers/dma/uniphier-xdmac.c

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// SPDX-License-Identifier: GPL-2.0
/*
* External DMA controller driver for UniPhier SoCs
* Copyright 2019 Socionext Inc.
* Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
*/
#include <linux/bitops.h>
#include <linux/bitfield.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "dmaengine.h"
#include "virt-dma.h"
#define XDMAC_CH_WIDTH 0x100
#define XDMAC_TFA 0x08
#define XDMAC_TFA_MCNT_MASK GENMASK(23, 16)
#define XDMAC_TFA_MASK GENMASK(5, 0)
#define XDMAC_SADM 0x10
#define XDMAC_SADM_STW_MASK GENMASK(25, 24)
#define XDMAC_SADM_SAM BIT(4)
#define XDMAC_SADM_SAM_FIXED XDMAC_SADM_SAM
#define XDMAC_SADM_SAM_INC 0
#define XDMAC_DADM 0x14
#define XDMAC_DADM_DTW_MASK XDMAC_SADM_STW_MASK
#define XDMAC_DADM_DAM XDMAC_SADM_SAM
#define XDMAC_DADM_DAM_FIXED XDMAC_SADM_SAM_FIXED
#define XDMAC_DADM_DAM_INC XDMAC_SADM_SAM_INC
#define XDMAC_EXSAD 0x18
#define XDMAC_EXDAD 0x1c
#define XDMAC_SAD 0x20
#define XDMAC_DAD 0x24
#define XDMAC_ITS 0x28
#define XDMAC_ITS_MASK GENMASK(25, 0)
#define XDMAC_TNUM 0x2c
#define XDMAC_TNUM_MASK GENMASK(15, 0)
#define XDMAC_TSS 0x30
#define XDMAC_TSS_REQ BIT(0)
#define XDMAC_IEN 0x34
#define XDMAC_IEN_ERRIEN BIT(1)
#define XDMAC_IEN_ENDIEN BIT(0)
#define XDMAC_STAT 0x40
#define XDMAC_STAT_TENF BIT(0)
#define XDMAC_IR 0x44
#define XDMAC_IR_ERRF BIT(1)
#define XDMAC_IR_ENDF BIT(0)
#define XDMAC_ID 0x48
#define XDMAC_ID_ERRIDF BIT(1)
#define XDMAC_ID_ENDIDF BIT(0)
#define XDMAC_MAX_CHANS 16
#define XDMAC_INTERVAL_CLKS 20
#define XDMAC_MAX_WORDS XDMAC_TNUM_MASK
/* cut lower bit for maintain alignment of maximum transfer size */
#define XDMAC_MAX_WORD_SIZE (XDMAC_ITS_MASK & ~GENMASK(3, 0))
#define UNIPHIER_XDMAC_BUSWIDTHS \
(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
struct uniphier_xdmac_desc_node {
dma_addr_t src;
dma_addr_t dst;
u32 burst_size;
u32 nr_burst;
};
struct uniphier_xdmac_desc {
struct virt_dma_desc vd;
unsigned int nr_node;
unsigned int cur_node;
enum dma_transfer_direction dir;
struct uniphier_xdmac_desc_node nodes[];
};
struct uniphier_xdmac_chan {
struct virt_dma_chan vc;
struct uniphier_xdmac_device *xdev;
struct uniphier_xdmac_desc *xd;
void __iomem *reg_ch_base;
struct dma_slave_config sconfig;
int id;
unsigned int req_factor;
};
struct uniphier_xdmac_device {
struct dma_device ddev;
void __iomem *reg_base;
int nr_chans;
struct uniphier_xdmac_chan channels[];
};
static struct uniphier_xdmac_chan *
to_uniphier_xdmac_chan(struct virt_dma_chan *vc)
{
return container_of(vc, struct uniphier_xdmac_chan, vc);
}
static struct uniphier_xdmac_desc *
to_uniphier_xdmac_desc(struct virt_dma_desc *vd)
{
return container_of(vd, struct uniphier_xdmac_desc, vd);
}
/* xc->vc.lock must be held by caller */
static struct uniphier_xdmac_desc *
uniphier_xdmac_next_desc(struct uniphier_xdmac_chan *xc)
{
struct virt_dma_desc *vd;
vd = vchan_next_desc(&xc->vc);
if (!vd)
return NULL;
list_del(&vd->node);
return to_uniphier_xdmac_desc(vd);
}
/* xc->vc.lock must be held by caller */
static void uniphier_xdmac_chan_start(struct uniphier_xdmac_chan *xc,
struct uniphier_xdmac_desc *xd)
{
u32 src_mode, src_addr, src_width;
u32 dst_mode, dst_addr, dst_width;
u32 val, its, tnum;
enum dma_slave_buswidth buswidth;
src_addr = xd->nodes[xd->cur_node].src;
dst_addr = xd->nodes[xd->cur_node].dst;
its = xd->nodes[xd->cur_node].burst_size;
tnum = xd->nodes[xd->cur_node].nr_burst;
/*
* The width of MEM side must be 4 or 8 bytes, that does not
* affect that of DEV side and transfer size.
*/
if (xd->dir == DMA_DEV_TO_MEM) {
src_mode = XDMAC_SADM_SAM_FIXED;
buswidth = xc->sconfig.src_addr_width;
} else {
src_mode = XDMAC_SADM_SAM_INC;
buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
}
src_width = FIELD_PREP(XDMAC_SADM_STW_MASK, __ffs(buswidth));
if (xd->dir == DMA_MEM_TO_DEV) {
dst_mode = XDMAC_DADM_DAM_FIXED;
buswidth = xc->sconfig.dst_addr_width;
} else {
dst_mode = XDMAC_DADM_DAM_INC;
buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
}
dst_width = FIELD_PREP(XDMAC_DADM_DTW_MASK, __ffs(buswidth));
/* setup transfer factor */
val = FIELD_PREP(XDMAC_TFA_MCNT_MASK, XDMAC_INTERVAL_CLKS);
val |= FIELD_PREP(XDMAC_TFA_MASK, xc->req_factor);
writel(val, xc->reg_ch_base + XDMAC_TFA);
/* setup the channel */
writel(lower_32_bits(src_addr), xc->reg_ch_base + XDMAC_SAD);
writel(upper_32_bits(src_addr), xc->reg_ch_base + XDMAC_EXSAD);
writel(lower_32_bits(dst_addr), xc->reg_ch_base + XDMAC_DAD);
writel(upper_32_bits(dst_addr), xc->reg_ch_base + XDMAC_EXDAD);
src_mode |= src_width;
dst_mode |= dst_width;
writel(src_mode, xc->reg_ch_base + XDMAC_SADM);
writel(dst_mode, xc->reg_ch_base + XDMAC_DADM);
writel(its, xc->reg_ch_base + XDMAC_ITS);
writel(tnum, xc->reg_ch_base + XDMAC_TNUM);
/* enable interrupt */
writel(XDMAC_IEN_ENDIEN | XDMAC_IEN_ERRIEN,
xc->reg_ch_base + XDMAC_IEN);
/* start XDMAC */
val = readl(xc->reg_ch_base + XDMAC_TSS);
val |= XDMAC_TSS_REQ;
writel(val, xc->reg_ch_base + XDMAC_TSS);
}
/* xc->vc.lock must be held by caller */
static int uniphier_xdmac_chan_stop(struct uniphier_xdmac_chan *xc)
{
u32 val;
/* disable interrupt */
val = readl(xc->reg_ch_base + XDMAC_IEN);
val &= ~(XDMAC_IEN_ENDIEN | XDMAC_IEN_ERRIEN);
writel(val, xc->reg_ch_base + XDMAC_IEN);
/* stop XDMAC */
val = readl(xc->reg_ch_base + XDMAC_TSS);
val &= ~XDMAC_TSS_REQ;
writel(0, xc->reg_ch_base + XDMAC_TSS);
/* wait until transfer is stopped */
return readl_poll_timeout(xc->reg_ch_base + XDMAC_STAT, val,
!(val & XDMAC_STAT_TENF), 100, 1000);
}
/* xc->vc.lock must be held by caller */
static void uniphier_xdmac_start(struct uniphier_xdmac_chan *xc)
{
struct uniphier_xdmac_desc *xd;
xd = uniphier_xdmac_next_desc(xc);
if (xd)
uniphier_xdmac_chan_start(xc, xd);
/* set desc to chan regardless of xd is null */
xc->xd = xd;
}
static void uniphier_xdmac_chan_irq(struct uniphier_xdmac_chan *xc)
{
u32 stat;
int ret;
spin_lock(&xc->vc.lock);
stat = readl(xc->reg_ch_base + XDMAC_ID);
if (stat & XDMAC_ID_ERRIDF) {
ret = uniphier_xdmac_chan_stop(xc);
if (ret)
dev_err(xc->xdev->ddev.dev,
"DMA transfer error with aborting issue\n");
else
dev_err(xc->xdev->ddev.dev,
"DMA transfer error\n");
} else if ((stat & XDMAC_ID_ENDIDF) && xc->xd) {
xc->xd->cur_node++;
if (xc->xd->cur_node >= xc->xd->nr_node) {
vchan_cookie_complete(&xc->xd->vd);
uniphier_xdmac_start(xc);
} else {
uniphier_xdmac_chan_start(xc, xc->xd);
}
}
/* write bits to clear */
writel(stat, xc->reg_ch_base + XDMAC_IR);
spin_unlock(&xc->vc.lock);
}
static irqreturn_t uniphier_xdmac_irq_handler(int irq, void *dev_id)
{
struct uniphier_xdmac_device *xdev = dev_id;
int i;
for (i = 0; i < xdev->nr_chans; i++)
uniphier_xdmac_chan_irq(&xdev->channels[i]);
return IRQ_HANDLED;
}
static void uniphier_xdmac_free_chan_resources(struct dma_chan *chan)
{
vchan_free_chan_resources(to_virt_chan(chan));
}
static struct dma_async_tx_descriptor *
uniphier_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst,
dma_addr_t src, size_t len, unsigned long flags)
{
struct virt_dma_chan *vc = to_virt_chan(chan);
struct uniphier_xdmac_desc *xd;
unsigned int nr;
size_t burst_size, tlen;
int i;
if (len > XDMAC_MAX_WORD_SIZE * XDMAC_MAX_WORDS)
return NULL;
nr = 1 + len / XDMAC_MAX_WORD_SIZE;
xd = kzalloc(struct_size(xd, nodes, nr), GFP_NOWAIT);
if (!xd)
return NULL;
for (i = 0; i < nr; i++) {
burst_size = min_t(size_t, len, XDMAC_MAX_WORD_SIZE);
xd->nodes[i].src = src;
xd->nodes[i].dst = dst;
xd->nodes[i].burst_size = burst_size;
xd->nodes[i].nr_burst = len / burst_size;
tlen = rounddown(len, burst_size);
src += tlen;
dst += tlen;
len -= tlen;
}
xd->dir = DMA_MEM_TO_MEM;
xd->nr_node = nr;
xd->cur_node = 0;
return vchan_tx_prep(vc, &xd->vd, flags);
}
static struct dma_async_tx_descriptor *
uniphier_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len,
enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct virt_dma_chan *vc = to_virt_chan(chan);
struct uniphier_xdmac_chan *xc = to_uniphier_xdmac_chan(vc);
struct uniphier_xdmac_desc *xd;
struct scatterlist *sg;
enum dma_slave_buswidth buswidth;
u32 maxburst;
int i;
if (!is_slave_direction(direction))
return NULL;
if (direction == DMA_DEV_TO_MEM) {
buswidth = xc->sconfig.src_addr_width;
maxburst = xc->sconfig.src_maxburst;
} else {
buswidth = xc->sconfig.dst_addr_width;
maxburst = xc->sconfig.dst_maxburst;
}
if (!maxburst)
maxburst = 1;
if (maxburst > xc->xdev->ddev.max_burst) {
dev_err(xc->xdev->ddev.dev,
"Exceed maximum number of burst words\n");
return NULL;
}
xd = kzalloc(struct_size(xd, nodes, sg_len), GFP_NOWAIT);
if (!xd)
return NULL;
for_each_sg(sgl, sg, sg_len, i) {
xd->nodes[i].src = (direction == DMA_DEV_TO_MEM)
? xc->sconfig.src_addr : sg_dma_address(sg);
xd->nodes[i].dst = (direction == DMA_MEM_TO_DEV)
? xc->sconfig.dst_addr : sg_dma_address(sg);
xd->nodes[i].burst_size = maxburst * buswidth;
xd->nodes[i].nr_burst =
sg_dma_len(sg) / xd->nodes[i].burst_size;
/*
* Currently transfer that size doesn't align the unit size
* (the number of burst words * bus-width) is not allowed,
* because the driver does not support the way to transfer
* residue size. As a matter of fact, in order to transfer
* arbitrary size, 'src_maxburst' or 'dst_maxburst' of
* dma_slave_config must be 1.
*/
if (sg_dma_len(sg) % xd->nodes[i].burst_size) {
dev_err(xc->xdev->ddev.dev,
"Unaligned transfer size: %d", sg_dma_len(sg));
kfree(xd);
return NULL;
}
if (xd->nodes[i].nr_burst > XDMAC_MAX_WORDS) {
dev_err(xc->xdev->ddev.dev,
"Exceed maximum transfer size");
kfree(xd);
return NULL;
}
}
xd->dir = direction;
xd->nr_node = sg_len;
xd->cur_node = 0;
return vchan_tx_prep(vc, &xd->vd, flags);
}
static int uniphier_xdmac_slave_config(struct dma_chan *chan,
struct dma_slave_config *config)
{
struct virt_dma_chan *vc = to_virt_chan(chan);
struct uniphier_xdmac_chan *xc = to_uniphier_xdmac_chan(vc);
memcpy(&xc->sconfig, config, sizeof(*config));
return 0;
}
static int uniphier_xdmac_terminate_all(struct dma_chan *chan)
{
struct virt_dma_chan *vc = to_virt_chan(chan);
struct uniphier_xdmac_chan *xc = to_uniphier_xdmac_chan(vc);
unsigned long flags;
int ret = 0;
LIST_HEAD(head);
spin_lock_irqsave(&vc->lock, flags);
if (xc->xd) {
vchan_terminate_vdesc(&xc->xd->vd);
xc->xd = NULL;
ret = uniphier_xdmac_chan_stop(xc);
}
vchan_get_all_descriptors(vc, &head);
spin_unlock_irqrestore(&vc->lock, flags);
vchan_dma_desc_free_list(vc, &head);
return ret;
}
static void uniphier_xdmac_synchronize(struct dma_chan *chan)
{
vchan_synchronize(to_virt_chan(chan));
}
static void uniphier_xdmac_issue_pending(struct dma_chan *chan)
{
struct virt_dma_chan *vc = to_virt_chan(chan);
struct uniphier_xdmac_chan *xc = to_uniphier_xdmac_chan(vc);
unsigned long flags;
spin_lock_irqsave(&vc->lock, flags);
if (vchan_issue_pending(vc) && !xc->xd)
uniphier_xdmac_start(xc);
spin_unlock_irqrestore(&vc->lock, flags);
}
static void uniphier_xdmac_desc_free(struct virt_dma_desc *vd)
{
kfree(to_uniphier_xdmac_desc(vd));
}
static void uniphier_xdmac_chan_init(struct uniphier_xdmac_device *xdev,
int ch)
{
struct uniphier_xdmac_chan *xc = &xdev->channels[ch];
xc->xdev = xdev;
xc->reg_ch_base = xdev->reg_base + XDMAC_CH_WIDTH * ch;
xc->vc.desc_free = uniphier_xdmac_desc_free;
vchan_init(&xc->vc, &xdev->ddev);
}
static struct dma_chan *of_dma_uniphier_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct uniphier_xdmac_device *xdev = ofdma->of_dma_data;
int chan_id = dma_spec->args[0];
if (chan_id >= xdev->nr_chans)
return NULL;
xdev->channels[chan_id].id = chan_id;
xdev->channels[chan_id].req_factor = dma_spec->args[1];
return dma_get_slave_channel(&xdev->channels[chan_id].vc.chan);
}
static int uniphier_xdmac_probe(struct platform_device *pdev)
{
struct uniphier_xdmac_device *xdev;
struct device *dev = &pdev->dev;
struct dma_device *ddev;
int irq;
int nr_chans;
int i, ret;
if (of_property_read_u32(dev->of_node, "dma-channels", &nr_chans))
return -EINVAL;
if (nr_chans > XDMAC_MAX_CHANS)
nr_chans = XDMAC_MAX_CHANS;
xdev = devm_kzalloc(dev, struct_size(xdev, channels, nr_chans),
GFP_KERNEL);
if (!xdev)
return -ENOMEM;
xdev->nr_chans = nr_chans;
xdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(xdev->reg_base))
return PTR_ERR(xdev->reg_base);
ddev = &xdev->ddev;
ddev->dev = dev;
dma_cap_zero(ddev->cap_mask);
dma_cap_set(DMA_MEMCPY, ddev->cap_mask);
dma_cap_set(DMA_SLAVE, ddev->cap_mask);
ddev->src_addr_widths = UNIPHIER_XDMAC_BUSWIDTHS;
ddev->dst_addr_widths = UNIPHIER_XDMAC_BUSWIDTHS;
ddev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
BIT(DMA_MEM_TO_MEM);
ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
ddev->max_burst = XDMAC_MAX_WORDS;
ddev->device_free_chan_resources = uniphier_xdmac_free_chan_resources;
ddev->device_prep_dma_memcpy = uniphier_xdmac_prep_dma_memcpy;
ddev->device_prep_slave_sg = uniphier_xdmac_prep_slave_sg;
ddev->device_config = uniphier_xdmac_slave_config;
ddev->device_terminate_all = uniphier_xdmac_terminate_all;
ddev->device_synchronize = uniphier_xdmac_synchronize;
ddev->device_tx_status = dma_cookie_status;
ddev->device_issue_pending = uniphier_xdmac_issue_pending;
INIT_LIST_HEAD(&ddev->channels);
for (i = 0; i < nr_chans; i++)
uniphier_xdmac_chan_init(xdev, i);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
ret = devm_request_irq(dev, irq, uniphier_xdmac_irq_handler,
IRQF_SHARED, "xdmac", xdev);
if (ret) {
dev_err(dev, "Failed to request IRQ\n");
return ret;
}
ret = dma_async_device_register(ddev);
if (ret) {
dev_err(dev, "Failed to register XDMA device\n");
return ret;
}
ret = of_dma_controller_register(dev->of_node,
of_dma_uniphier_xlate, xdev);
if (ret) {
dev_err(dev, "Failed to register XDMA controller\n");
goto out_unregister_dmac;
}
platform_set_drvdata(pdev, xdev);
dev_info(&pdev->dev, "UniPhier XDMAC driver (%d channels)\n",
nr_chans);
return 0;
out_unregister_dmac:
dma_async_device_unregister(ddev);
return ret;
}
static int uniphier_xdmac_remove(struct platform_device *pdev)
{
struct uniphier_xdmac_device *xdev = platform_get_drvdata(pdev);
struct dma_device *ddev = &xdev->ddev;
struct dma_chan *chan;
int ret;
/*
* Before reaching here, almost all descriptors have been freed by the
* ->device_free_chan_resources() hook. However, each channel might
* be still holding one descriptor that was on-flight at that moment.
* Terminate it to make sure this hardware is no longer running. Then,
* free the channel resources once again to avoid memory leak.
*/
list_for_each_entry(chan, &ddev->channels, device_node) {
ret = dmaengine_terminate_sync(chan);
if (ret)
return ret;
uniphier_xdmac_free_chan_resources(chan);
}
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(ddev);
return 0;
}
static const struct of_device_id uniphier_xdmac_match[] = {
{ .compatible = "socionext,uniphier-xdmac" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, uniphier_xdmac_match);
static struct platform_driver uniphier_xdmac_driver = {
.probe = uniphier_xdmac_probe,
.remove = uniphier_xdmac_remove,
.driver = {
.name = "uniphier-xdmac",
.of_match_table = uniphier_xdmac_match,
},
};
module_platform_driver(uniphier_xdmac_driver);
MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
MODULE_DESCRIPTION("UniPhier external DMA controller driver");
MODULE_LICENSE("GPL v2");