linux/drivers/dma/idma64.c

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/*
* Core driver for the Intel integrated DMA 64-bit
*
* Copyright (C) 2015 Intel Corporation
* Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "idma64.h"
/* Platform driver name */
#define DRV_NAME "idma64"
/* For now we support only two channels */
#define IDMA64_NR_CHAN 2
/* ---------------------------------------------------------------------- */
static struct device *chan2dev(struct dma_chan *chan)
{
return &chan->dev->device;
}
/* ---------------------------------------------------------------------- */
static void idma64_off(struct idma64 *idma64)
{
unsigned short count = 100;
dma_writel(idma64, CFG, 0);
channel_clear_bit(idma64, MASK(XFER), idma64->all_chan_mask);
channel_clear_bit(idma64, MASK(BLOCK), idma64->all_chan_mask);
channel_clear_bit(idma64, MASK(SRC_TRAN), idma64->all_chan_mask);
channel_clear_bit(idma64, MASK(DST_TRAN), idma64->all_chan_mask);
channel_clear_bit(idma64, MASK(ERROR), idma64->all_chan_mask);
do {
cpu_relax();
} while (dma_readl(idma64, CFG) & IDMA64_CFG_DMA_EN && --count);
}
static void idma64_on(struct idma64 *idma64)
{
dma_writel(idma64, CFG, IDMA64_CFG_DMA_EN);
}
/* ---------------------------------------------------------------------- */
static void idma64_chan_init(struct idma64 *idma64, struct idma64_chan *idma64c)
{
u32 cfghi = IDMA64C_CFGH_SRC_PER(1) | IDMA64C_CFGH_DST_PER(0);
u32 cfglo = 0;
/* Enforce FIFO drain when channel is suspended */
cfglo |= IDMA64C_CFGL_CH_DRAIN;
/* Set default burst alignment */
cfglo |= IDMA64C_CFGL_DST_BURST_ALIGN | IDMA64C_CFGL_SRC_BURST_ALIGN;
channel_writel(idma64c, CFG_LO, cfglo);
channel_writel(idma64c, CFG_HI, cfghi);
/* Enable interrupts */
channel_set_bit(idma64, MASK(XFER), idma64c->mask);
channel_set_bit(idma64, MASK(ERROR), idma64c->mask);
/*
* Enforce the controller to be turned on.
*
* The iDMA is turned off in ->probe() and looses context during system
* suspend / resume cycle. That's why we have to enable it each time we
* use it.
*/
idma64_on(idma64);
}
static void idma64_chan_stop(struct idma64 *idma64, struct idma64_chan *idma64c)
{
channel_clear_bit(idma64, CH_EN, idma64c->mask);
}
static void idma64_chan_start(struct idma64 *idma64, struct idma64_chan *idma64c)
{
struct idma64_desc *desc = idma64c->desc;
struct idma64_hw_desc *hw = &desc->hw[0];
channel_writeq(idma64c, SAR, 0);
channel_writeq(idma64c, DAR, 0);
channel_writel(idma64c, CTL_HI, IDMA64C_CTLH_BLOCK_TS(~0UL));
channel_writel(idma64c, CTL_LO, IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN);
channel_writeq(idma64c, LLP, hw->llp);
channel_set_bit(idma64, CH_EN, idma64c->mask);
}
static void idma64_stop_transfer(struct idma64_chan *idma64c)
{
struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device);
idma64_chan_stop(idma64, idma64c);
}
static void idma64_start_transfer(struct idma64_chan *idma64c)
{
struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device);
struct virt_dma_desc *vdesc;
/* Get the next descriptor */
vdesc = vchan_next_desc(&idma64c->vchan);
if (!vdesc) {
idma64c->desc = NULL;
return;
}
list_del(&vdesc->node);
idma64c->desc = to_idma64_desc(vdesc);
/* Configure the channel */
idma64_chan_init(idma64, idma64c);
/* Start the channel with a new descriptor */
idma64_chan_start(idma64, idma64c);
}
/* ---------------------------------------------------------------------- */
static void idma64_chan_irq(struct idma64 *idma64, unsigned short c,
u32 status_err, u32 status_xfer)
{
struct idma64_chan *idma64c = &idma64->chan[c];
struct idma64_desc *desc;
unsigned long flags;
spin_lock_irqsave(&idma64c->vchan.lock, flags);
desc = idma64c->desc;
if (desc) {
if (status_err & (1 << c)) {
dma_writel(idma64, CLEAR(ERROR), idma64c->mask);
desc->status = DMA_ERROR;
} else if (status_xfer & (1 << c)) {
dma_writel(idma64, CLEAR(XFER), idma64c->mask);
desc->status = DMA_COMPLETE;
vchan_cookie_complete(&desc->vdesc);
idma64_start_transfer(idma64c);
}
/* idma64_start_transfer() updates idma64c->desc */
if (idma64c->desc == NULL || desc->status == DMA_ERROR)
idma64_stop_transfer(idma64c);
}
spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
}
static irqreturn_t idma64_irq(int irq, void *dev)
{
struct idma64 *idma64 = dev;
u32 status = dma_readl(idma64, STATUS_INT);
u32 status_xfer;
u32 status_err;
unsigned short i;
dev_vdbg(idma64->dma.dev, "%s: status=%#x\n", __func__, status);
/* Check if we have any interrupt from the DMA controller */
if (!status)
return IRQ_NONE;
/* Disable interrupts */
channel_clear_bit(idma64, MASK(XFER), idma64->all_chan_mask);
channel_clear_bit(idma64, MASK(ERROR), idma64->all_chan_mask);
status_xfer = dma_readl(idma64, RAW(XFER));
status_err = dma_readl(idma64, RAW(ERROR));
for (i = 0; i < idma64->dma.chancnt; i++)
idma64_chan_irq(idma64, i, status_err, status_xfer);
/* Re-enable interrupts */
channel_set_bit(idma64, MASK(XFER), idma64->all_chan_mask);
channel_set_bit(idma64, MASK(ERROR), idma64->all_chan_mask);
return IRQ_HANDLED;
}
/* ---------------------------------------------------------------------- */
static struct idma64_desc *idma64_alloc_desc(unsigned int ndesc)
{
struct idma64_desc *desc;
desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
if (!desc)
return NULL;
desc->hw = kcalloc(ndesc, sizeof(*desc->hw), GFP_NOWAIT);
if (!desc->hw) {
kfree(desc);
return NULL;
}
return desc;
}
static void idma64_desc_free(struct idma64_chan *idma64c,
struct idma64_desc *desc)
{
struct idma64_hw_desc *hw;
if (desc->ndesc) {
unsigned int i = desc->ndesc;
do {
hw = &desc->hw[--i];
dma_pool_free(idma64c->pool, hw->lli, hw->llp);
} while (i);
}
kfree(desc->hw);
kfree(desc);
}
static void idma64_vdesc_free(struct virt_dma_desc *vdesc)
{
struct idma64_chan *idma64c = to_idma64_chan(vdesc->tx.chan);
idma64_desc_free(idma64c, to_idma64_desc(vdesc));
}
static u64 idma64_hw_desc_fill(struct idma64_hw_desc *hw,
struct dma_slave_config *config,
enum dma_transfer_direction direction, u64 llp)
{
struct idma64_lli *lli = hw->lli;
u64 sar, dar;
u32 ctlhi = IDMA64C_CTLH_BLOCK_TS(hw->len);
u32 ctllo = IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN;
u32 src_width, dst_width;
if (direction == DMA_MEM_TO_DEV) {
sar = hw->phys;
dar = config->dst_addr;
ctllo |= IDMA64C_CTLL_DST_FIX | IDMA64C_CTLL_SRC_INC |
IDMA64C_CTLL_FC_M2P;
src_width = min_t(u32, 2, __fls(sar | hw->len));
dst_width = __fls(config->dst_addr_width);
} else { /* DMA_DEV_TO_MEM */
sar = config->src_addr;
dar = hw->phys;
ctllo |= IDMA64C_CTLL_DST_INC | IDMA64C_CTLL_SRC_FIX |
IDMA64C_CTLL_FC_P2M;
src_width = __fls(config->src_addr_width);
dst_width = min_t(u32, 2, __fls(dar | hw->len));
}
lli->sar = sar;
lli->dar = dar;
lli->ctlhi = ctlhi;
lli->ctllo = ctllo |
IDMA64C_CTLL_SRC_MSIZE(config->src_maxburst) |
IDMA64C_CTLL_DST_MSIZE(config->dst_maxburst) |
IDMA64C_CTLL_DST_WIDTH(dst_width) |
IDMA64C_CTLL_SRC_WIDTH(src_width);
lli->llp = llp;
return hw->llp;
}
static void idma64_desc_fill(struct idma64_chan *idma64c,
struct idma64_desc *desc)
{
struct dma_slave_config *config = &idma64c->config;
struct idma64_hw_desc *hw = &desc->hw[desc->ndesc - 1];
struct idma64_lli *lli = hw->lli;
u64 llp = 0;
unsigned int i = desc->ndesc;
/* Fill the hardware descriptors and link them to a list */
do {
hw = &desc->hw[--i];
llp = idma64_hw_desc_fill(hw, config, desc->direction, llp);
desc->length += hw->len;
} while (i);
/* Trigger interrupt after last block */
lli->ctllo |= IDMA64C_CTLL_INT_EN;
}
static struct dma_async_tx_descriptor *idma64_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 idma64_chan *idma64c = to_idma64_chan(chan);
struct idma64_desc *desc;
struct scatterlist *sg;
unsigned int i;
desc = idma64_alloc_desc(sg_len);
if (!desc)
return NULL;
for_each_sg(sgl, sg, sg_len, i) {
struct idma64_hw_desc *hw = &desc->hw[i];
/* Allocate DMA capable memory for hardware descriptor */
hw->lli = dma_pool_alloc(idma64c->pool, GFP_NOWAIT, &hw->llp);
if (!hw->lli) {
desc->ndesc = i;
idma64_desc_free(idma64c, desc);
return NULL;
}
hw->phys = sg_dma_address(sg);
hw->len = sg_dma_len(sg);
}
desc->ndesc = sg_len;
desc->direction = direction;
desc->status = DMA_IN_PROGRESS;
idma64_desc_fill(idma64c, desc);
return vchan_tx_prep(&idma64c->vchan, &desc->vdesc, flags);
}
static void idma64_issue_pending(struct dma_chan *chan)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
unsigned long flags;
spin_lock_irqsave(&idma64c->vchan.lock, flags);
if (vchan_issue_pending(&idma64c->vchan) && !idma64c->desc)
idma64_start_transfer(idma64c);
spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
}
static size_t idma64_active_desc_size(struct idma64_chan *idma64c)
{
struct idma64_desc *desc = idma64c->desc;
struct idma64_hw_desc *hw;
size_t bytes = desc->length;
u64 llp;
u32 ctlhi;
unsigned int i = 0;
llp = channel_readq(idma64c, LLP);
do {
hw = &desc->hw[i];
} while ((hw->llp != llp) && (++i < desc->ndesc));
if (!i)
return bytes;
do {
bytes -= desc->hw[--i].len;
} while (i);
ctlhi = channel_readl(idma64c, CTL_HI);
return bytes - IDMA64C_CTLH_BLOCK_TS(ctlhi);
}
static enum dma_status idma64_tx_status(struct dma_chan *chan,
dma_cookie_t cookie, struct dma_tx_state *state)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
struct virt_dma_desc *vdesc;
enum dma_status status;
size_t bytes;
unsigned long flags;
status = dma_cookie_status(chan, cookie, state);
if (status == DMA_COMPLETE)
return status;
spin_lock_irqsave(&idma64c->vchan.lock, flags);
vdesc = vchan_find_desc(&idma64c->vchan, cookie);
if (idma64c->desc && cookie == idma64c->desc->vdesc.tx.cookie) {
bytes = idma64_active_desc_size(idma64c);
dma_set_residue(state, bytes);
status = idma64c->desc->status;
} else if (vdesc) {
bytes = to_idma64_desc(vdesc)->length;
dma_set_residue(state, bytes);
}
spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
return status;
}
static void convert_burst(u32 *maxburst)
{
if (*maxburst)
*maxburst = __fls(*maxburst);
else
*maxburst = 0;
}
static int idma64_slave_config(struct dma_chan *chan,
struct dma_slave_config *config)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
/* Check if chan will be configured for slave transfers */
if (!is_slave_direction(config->direction))
return -EINVAL;
memcpy(&idma64c->config, config, sizeof(idma64c->config));
convert_burst(&idma64c->config.src_maxburst);
convert_burst(&idma64c->config.dst_maxburst);
return 0;
}
static void idma64_chan_deactivate(struct idma64_chan *idma64c)
{
unsigned short count = 100;
u32 cfglo;
cfglo = channel_readl(idma64c, CFG_LO);
channel_writel(idma64c, CFG_LO, cfglo | IDMA64C_CFGL_CH_SUSP);
do {
udelay(1);
cfglo = channel_readl(idma64c, CFG_LO);
} while (!(cfglo & IDMA64C_CFGL_FIFO_EMPTY) && --count);
}
static void idma64_chan_activate(struct idma64_chan *idma64c)
{
u32 cfglo;
cfglo = channel_readl(idma64c, CFG_LO);
channel_writel(idma64c, CFG_LO, cfglo & ~IDMA64C_CFGL_CH_SUSP);
}
static int idma64_pause(struct dma_chan *chan)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
unsigned long flags;
spin_lock_irqsave(&idma64c->vchan.lock, flags);
if (idma64c->desc && idma64c->desc->status == DMA_IN_PROGRESS) {
idma64_chan_deactivate(idma64c);
idma64c->desc->status = DMA_PAUSED;
}
spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
return 0;
}
static int idma64_resume(struct dma_chan *chan)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
unsigned long flags;
spin_lock_irqsave(&idma64c->vchan.lock, flags);
if (idma64c->desc && idma64c->desc->status == DMA_PAUSED) {
idma64c->desc->status = DMA_IN_PROGRESS;
idma64_chan_activate(idma64c);
}
spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
return 0;
}
static int idma64_terminate_all(struct dma_chan *chan)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&idma64c->vchan.lock, flags);
idma64_chan_deactivate(idma64c);
idma64_stop_transfer(idma64c);
if (idma64c->desc) {
idma64_vdesc_free(&idma64c->desc->vdesc);
idma64c->desc = NULL;
}
vchan_get_all_descriptors(&idma64c->vchan, &head);
spin_unlock_irqrestore(&idma64c->vchan.lock, flags);
vchan_dma_desc_free_list(&idma64c->vchan, &head);
return 0;
}
static int idma64_alloc_chan_resources(struct dma_chan *chan)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
/* Create a pool of consistent memory blocks for hardware descriptors */
idma64c->pool = dma_pool_create(dev_name(chan2dev(chan)),
chan->device->dev,
sizeof(struct idma64_lli), 8, 0);
if (!idma64c->pool) {
dev_err(chan2dev(chan), "No memory for descriptors\n");
return -ENOMEM;
}
return 0;
}
static void idma64_free_chan_resources(struct dma_chan *chan)
{
struct idma64_chan *idma64c = to_idma64_chan(chan);
vchan_free_chan_resources(to_virt_chan(chan));
dma_pool_destroy(idma64c->pool);
idma64c->pool = NULL;
}
/* ---------------------------------------------------------------------- */
#define IDMA64_BUSWIDTHS \
BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
static int idma64_probe(struct idma64_chip *chip)
{
struct idma64 *idma64;
unsigned short nr_chan = IDMA64_NR_CHAN;
unsigned short i;
int ret;
idma64 = devm_kzalloc(chip->dev, sizeof(*idma64), GFP_KERNEL);
if (!idma64)
return -ENOMEM;
idma64->regs = chip->regs;
chip->idma64 = idma64;
idma64->chan = devm_kcalloc(chip->dev, nr_chan, sizeof(*idma64->chan),
GFP_KERNEL);
if (!idma64->chan)
return -ENOMEM;
idma64->all_chan_mask = (1 << nr_chan) - 1;
/* Turn off iDMA controller */
idma64_off(idma64);
ret = devm_request_irq(chip->dev, chip->irq, idma64_irq, IRQF_SHARED,
dev_name(chip->dev), idma64);
if (ret)
return ret;
INIT_LIST_HEAD(&idma64->dma.channels);
for (i = 0; i < nr_chan; i++) {
struct idma64_chan *idma64c = &idma64->chan[i];
idma64c->vchan.desc_free = idma64_vdesc_free;
vchan_init(&idma64c->vchan, &idma64->dma);
idma64c->regs = idma64->regs + i * IDMA64_CH_LENGTH;
idma64c->mask = BIT(i);
}
dma_cap_set(DMA_SLAVE, idma64->dma.cap_mask);
dma_cap_set(DMA_PRIVATE, idma64->dma.cap_mask);
idma64->dma.device_alloc_chan_resources = idma64_alloc_chan_resources;
idma64->dma.device_free_chan_resources = idma64_free_chan_resources;
idma64->dma.device_prep_slave_sg = idma64_prep_slave_sg;
idma64->dma.device_issue_pending = idma64_issue_pending;
idma64->dma.device_tx_status = idma64_tx_status;
idma64->dma.device_config = idma64_slave_config;
idma64->dma.device_pause = idma64_pause;
idma64->dma.device_resume = idma64_resume;
idma64->dma.device_terminate_all = idma64_terminate_all;
idma64->dma.src_addr_widths = IDMA64_BUSWIDTHS;
idma64->dma.dst_addr_widths = IDMA64_BUSWIDTHS;
idma64->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
idma64->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
idma64->dma.dev = chip->dev;
ret = dma_async_device_register(&idma64->dma);
if (ret)
return ret;
dev_info(chip->dev, "Found Intel integrated DMA 64-bit\n");
return 0;
}
static int idma64_remove(struct idma64_chip *chip)
{
struct idma64 *idma64 = chip->idma64;
unsigned short i;
dma_async_device_unregister(&idma64->dma);
/*
* Explicitly call devm_request_irq() to avoid the side effects with
* the scheduled tasklets.
*/
devm_free_irq(chip->dev, chip->irq, idma64);
for (i = 0; i < idma64->dma.chancnt; i++) {
struct idma64_chan *idma64c = &idma64->chan[i];
tasklet_kill(&idma64c->vchan.task);
}
return 0;
}
/* ---------------------------------------------------------------------- */
static int idma64_platform_probe(struct platform_device *pdev)
{
struct idma64_chip *chip;
struct device *dev = &pdev->dev;
struct resource *mem;
int ret;
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->irq = platform_get_irq(pdev, 0);
if (chip->irq < 0)
return chip->irq;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
chip->regs = devm_ioremap_resource(dev, mem);
if (IS_ERR(chip->regs))
return PTR_ERR(chip->regs);
ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
if (ret)
return ret;
chip->dev = dev;
ret = idma64_probe(chip);
if (ret)
return ret;
platform_set_drvdata(pdev, chip);
return 0;
}
static int idma64_platform_remove(struct platform_device *pdev)
{
struct idma64_chip *chip = platform_get_drvdata(pdev);
return idma64_remove(chip);
}
#ifdef CONFIG_PM_SLEEP
static int idma64_pm_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct idma64_chip *chip = platform_get_drvdata(pdev);
idma64_off(chip->idma64);
return 0;
}
static int idma64_pm_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct idma64_chip *chip = platform_get_drvdata(pdev);
idma64_on(chip->idma64);
return 0;
}
#endif /* CONFIG_PM_SLEEP */
static const struct dev_pm_ops idma64_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(idma64_pm_suspend, idma64_pm_resume)
};
static struct platform_driver idma64_platform_driver = {
.probe = idma64_platform_probe,
.remove = idma64_platform_remove,
.driver = {
.name = DRV_NAME,
.pm = &idma64_dev_pm_ops,
},
};
module_platform_driver(idma64_platform_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("iDMA64 core driver");
MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
MODULE_ALIAS("platform:" DRV_NAME);