linux/drivers/dma/idma64.c
Andy Shevchenko 667dfed986 dmaengine: add a driver for Intel integrated DMA 64-bit
Intel integrated DMA (iDMA) 64-bit is a specific IP that is used as a part of
LPSS devices such as HSUART or SPI. The iDMA IP is attached for private
usage on each host controller independently.

While it has similarities with Synopsys DesignWare DMA, the following
distinctions doesn't allow to use the existing driver:
- 64-bit mode with corresponding changes in Hardware Linked List data structure
- many slight differences in the channel registers

Moreover this driver is based on the DMA virtual channels framework that helps
to make the driver cleaner and easy to understand.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-07-28 09:56:17 +01:00

711 lines
18 KiB
C

/*
* 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);