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linux-stable/drivers/dma/at_hdmac.c
Uwe Kleine-König ae3f38e495 dmaengine: at_hdmac: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230919133207.1400430-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2023-09-28 13:10:45 +05:30

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems)
*
* Copyright (C) 2008 Atmel Corporation
* Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries
*
* This supports the Atmel AHB DMA Controller found in several Atmel SoCs.
* The only Atmel DMA Controller that is not covered by this driver is the one
* found on AT91SAM9263.
*/
#include <dt-bindings/dma/at91.h>
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/overflow.h>
#include <linux/of_platform.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "dmaengine.h"
#include "virt-dma.h"
/*
* Glossary
* --------
*
* at_hdmac : Name of the ATmel AHB DMA Controller
* at_dma_ / atdma : ATmel DMA controller entity related
* atc_ / atchan : ATmel DMA Channel entity related
*/
#define AT_DMA_MAX_NR_CHANNELS 8
/* Global Configuration Register */
#define AT_DMA_GCFG 0x00
#define AT_DMA_IF_BIGEND(i) BIT((i)) /* AHB-Lite Interface i in Big-endian mode */
#define AT_DMA_ARB_CFG BIT(4) /* Arbiter mode. */
/* Controller Enable Register */
#define AT_DMA_EN 0x04
#define AT_DMA_ENABLE BIT(0)
/* Software Single Request Register */
#define AT_DMA_SREQ 0x08
#define AT_DMA_SSREQ(x) BIT((x) << 1) /* Request a source single transfer on channel x */
#define AT_DMA_DSREQ(x) BIT(1 + ((x) << 1)) /* Request a destination single transfer on channel x */
/* Software Chunk Transfer Request Register */
#define AT_DMA_CREQ 0x0c
#define AT_DMA_SCREQ(x) BIT((x) << 1) /* Request a source chunk transfer on channel x */
#define AT_DMA_DCREQ(x) BIT(1 + ((x) << 1)) /* Request a destination chunk transfer on channel x */
/* Software Last Transfer Flag Register */
#define AT_DMA_LAST 0x10
#define AT_DMA_SLAST(x) BIT((x) << 1) /* This src rq is last tx of buffer on channel x */
#define AT_DMA_DLAST(x) BIT(1 + ((x) << 1)) /* This dst rq is last tx of buffer on channel x */
/* Request Synchronization Register */
#define AT_DMA_SYNC 0x14
#define AT_DMA_SYR(h) BIT((h)) /* Synchronize handshake line h */
/* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */
#define AT_DMA_EBCIER 0x18 /* Enable register */
#define AT_DMA_EBCIDR 0x1c /* Disable register */
#define AT_DMA_EBCIMR 0x20 /* Mask Register */
#define AT_DMA_EBCISR 0x24 /* Status Register */
#define AT_DMA_CBTC_OFFSET 8
#define AT_DMA_ERR_OFFSET 16
#define AT_DMA_BTC(x) BIT((x))
#define AT_DMA_CBTC(x) BIT(AT_DMA_CBTC_OFFSET + (x))
#define AT_DMA_ERR(x) BIT(AT_DMA_ERR_OFFSET + (x))
/* Channel Handler Enable Register */
#define AT_DMA_CHER 0x28
#define AT_DMA_ENA(x) BIT((x))
#define AT_DMA_SUSP(x) BIT(8 + (x))
#define AT_DMA_KEEP(x) BIT(24 + (x))
/* Channel Handler Disable Register */
#define AT_DMA_CHDR 0x2c
#define AT_DMA_DIS(x) BIT(x)
#define AT_DMA_RES(x) BIT(8 + (x))
/* Channel Handler Status Register */
#define AT_DMA_CHSR 0x30
#define AT_DMA_EMPT(x) BIT(16 + (x))
#define AT_DMA_STAL(x) BIT(24 + (x))
/* Channel registers base address */
#define AT_DMA_CH_REGS_BASE 0x3c
#define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */
/* Hardware register offset for each channel */
#define ATC_SADDR_OFFSET 0x00 /* Source Address Register */
#define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */
#define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */
#define ATC_CTRLA_OFFSET 0x0c /* Control A Register */
#define ATC_CTRLB_OFFSET 0x10 /* Control B Register */
#define ATC_CFG_OFFSET 0x14 /* Configuration Register */
#define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */
#define ATC_DPIP_OFFSET 0x1c /* Dst PIP Configuration Register */
/* Bitfield definitions */
/* Bitfields in DSCR */
#define ATC_DSCR_IF GENMASK(1, 0) /* Dsc feched via AHB-Lite Interface */
/* Bitfields in CTRLA */
#define ATC_BTSIZE_MAX GENMASK(15, 0) /* Maximum Buffer Transfer Size */
#define ATC_BTSIZE GENMASK(15, 0) /* Buffer Transfer Size */
#define ATC_SCSIZE GENMASK(18, 16) /* Source Chunk Transfer Size */
#define ATC_DCSIZE GENMASK(22, 20) /* Destination Chunk Transfer Size */
#define ATC_SRC_WIDTH GENMASK(25, 24) /* Source Single Transfer Size */
#define ATC_DST_WIDTH GENMASK(29, 28) /* Destination Single Transfer Size */
#define ATC_DONE BIT(31) /* Tx Done (only written back in descriptor) */
/* Bitfields in CTRLB */
#define ATC_SIF GENMASK(1, 0) /* Src tx done via AHB-Lite Interface i */
#define ATC_DIF GENMASK(5, 4) /* Dst tx done via AHB-Lite Interface i */
#define AT_DMA_MEM_IF 0x0 /* interface 0 as memory interface */
#define AT_DMA_PER_IF 0x1 /* interface 1 as peripheral interface */
#define ATC_SRC_PIP BIT(8) /* Source Picture-in-Picture enabled */
#define ATC_DST_PIP BIT(12) /* Destination Picture-in-Picture enabled */
#define ATC_SRC_DSCR_DIS BIT(16) /* Src Descriptor fetch disable */
#define ATC_DST_DSCR_DIS BIT(20) /* Dst Descriptor fetch disable */
#define ATC_FC GENMASK(23, 21) /* Choose Flow Controller */
#define ATC_FC_MEM2MEM 0x0 /* Mem-to-Mem (DMA) */
#define ATC_FC_MEM2PER 0x1 /* Mem-to-Periph (DMA) */
#define ATC_FC_PER2MEM 0x2 /* Periph-to-Mem (DMA) */
#define ATC_FC_PER2PER 0x3 /* Periph-to-Periph (DMA) */
#define ATC_FC_PER2MEM_PER 0x4 /* Periph-to-Mem (Peripheral) */
#define ATC_FC_MEM2PER_PER 0x5 /* Mem-to-Periph (Peripheral) */
#define ATC_FC_PER2PER_SRCPER 0x6 /* Periph-to-Periph (Src Peripheral) */
#define ATC_FC_PER2PER_DSTPER 0x7 /* Periph-to-Periph (Dst Peripheral) */
#define ATC_SRC_ADDR_MODE GENMASK(25, 24)
#define ATC_SRC_ADDR_MODE_INCR 0x0 /* Incrementing Mode */
#define ATC_SRC_ADDR_MODE_DECR 0x1 /* Decrementing Mode */
#define ATC_SRC_ADDR_MODE_FIXED 0x2 /* Fixed Mode */
#define ATC_DST_ADDR_MODE GENMASK(29, 28)
#define ATC_DST_ADDR_MODE_INCR 0x0 /* Incrementing Mode */
#define ATC_DST_ADDR_MODE_DECR 0x1 /* Decrementing Mode */
#define ATC_DST_ADDR_MODE_FIXED 0x2 /* Fixed Mode */
#define ATC_IEN BIT(30) /* BTC interrupt enable (active low) */
#define ATC_AUTO BIT(31) /* Auto multiple buffer tx enable */
/* Bitfields in CFG */
#define ATC_SRC_PER GENMASK(3, 0) /* Channel src rq associated with periph handshaking ifc h */
#define ATC_DST_PER GENMASK(7, 4) /* Channel dst rq associated with periph handshaking ifc h */
#define ATC_SRC_REP BIT(8) /* Source Replay Mod */
#define ATC_SRC_H2SEL BIT(9) /* Source Handshaking Mod */
#define ATC_SRC_PER_MSB GENMASK(11, 10) /* Channel src rq (most significant bits) */
#define ATC_DST_REP BIT(12) /* Destination Replay Mod */
#define ATC_DST_H2SEL BIT(13) /* Destination Handshaking Mod */
#define ATC_DST_PER_MSB GENMASK(15, 14) /* Channel dst rq (most significant bits) */
#define ATC_SOD BIT(16) /* Stop On Done */
#define ATC_LOCK_IF BIT(20) /* Interface Lock */
#define ATC_LOCK_B BIT(21) /* AHB Bus Lock */
#define ATC_LOCK_IF_L BIT(22) /* Master Interface Arbiter Lock */
#define ATC_AHB_PROT GENMASK(26, 24) /* AHB Protection */
#define ATC_FIFOCFG GENMASK(29, 28) /* FIFO Request Configuration */
#define ATC_FIFOCFG_LARGESTBURST 0x0
#define ATC_FIFOCFG_HALFFIFO 0x1
#define ATC_FIFOCFG_ENOUGHSPACE 0x2
/* Bitfields in SPIP */
#define ATC_SPIP_HOLE GENMASK(15, 0)
#define ATC_SPIP_BOUNDARY GENMASK(25, 16)
/* Bitfields in DPIP */
#define ATC_DPIP_HOLE GENMASK(15, 0)
#define ATC_DPIP_BOUNDARY GENMASK(25, 16)
#define ATC_PER_MSB GENMASK(5, 4) /* Extract MSBs of a handshaking identifier */
#define ATC_SRC_PER_ID(id) \
({ typeof(id) _id = (id); \
FIELD_PREP(ATC_SRC_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \
FIELD_PREP(ATC_SRC_PER, _id); })
#define ATC_DST_PER_ID(id) \
({ typeof(id) _id = (id); \
FIELD_PREP(ATC_DST_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \
FIELD_PREP(ATC_DST_PER, _id); })
/*-- descriptors -----------------------------------------------------*/
/* LLI == Linked List Item; aka DMA buffer descriptor */
struct at_lli {
/* values that are not changed by hardware */
u32 saddr;
u32 daddr;
/* value that may get written back: */
u32 ctrla;
/* more values that are not changed by hardware */
u32 ctrlb;
u32 dscr; /* chain to next lli */
};
/**
* struct atdma_sg - atdma scatter gather entry
* @len: length of the current Linked List Item.
* @lli: linked list item that is passed to the DMA controller
* @lli_phys: physical address of the LLI.
*/
struct atdma_sg {
unsigned int len;
struct at_lli *lli;
dma_addr_t lli_phys;
};
/**
* struct at_desc - software descriptor
* @vd: pointer to the virtual dma descriptor.
* @atchan: pointer to the atmel dma channel.
* @total_len: total transaction byte count
* @sg_len: number of sg entries.
* @sg: array of sgs.
*/
struct at_desc {
struct virt_dma_desc vd;
struct at_dma_chan *atchan;
size_t total_len;
unsigned int sglen;
/* Interleaved data */
size_t boundary;
size_t dst_hole;
size_t src_hole;
/* Memset temporary buffer */
bool memset_buffer;
dma_addr_t memset_paddr;
int *memset_vaddr;
struct atdma_sg sg[];
};
/*-- Channels --------------------------------------------------------*/
/**
* atc_status - information bits stored in channel status flag
*
* Manipulated with atomic operations.
*/
enum atc_status {
ATC_IS_PAUSED = 1,
ATC_IS_CYCLIC = 24,
};
/**
* struct at_dma_chan - internal representation of an Atmel HDMAC channel
* @vc: virtual dma channel entry.
* @atdma: pointer to the driver data.
* @ch_regs: memory mapped register base
* @mask: channel index in a mask
* @per_if: peripheral interface
* @mem_if: memory interface
* @status: transmit status information from irq/prep* functions
* to tasklet (use atomic operations)
* @save_cfg: configuration register that is saved on suspend/resume cycle
* @save_dscr: for cyclic operations, preserve next descriptor address in
* the cyclic list on suspend/resume cycle
* @dma_sconfig: configuration for slave transfers, passed via
* .device_config
* @desc: pointer to the atmel dma descriptor.
*/
struct at_dma_chan {
struct virt_dma_chan vc;
struct at_dma *atdma;
void __iomem *ch_regs;
u8 mask;
u8 per_if;
u8 mem_if;
unsigned long status;
u32 save_cfg;
u32 save_dscr;
struct dma_slave_config dma_sconfig;
bool cyclic;
struct at_desc *desc;
};
#define channel_readl(atchan, name) \
__raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET)
#define channel_writel(atchan, name, val) \
__raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET)
/*
* Fix sconfig's burst size according to at_hdmac. We need to convert them as:
* 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7.
*
* This can be done by finding most significant bit set.
*/
static inline void convert_burst(u32 *maxburst)
{
if (*maxburst > 1)
*maxburst = fls(*maxburst) - 2;
else
*maxburst = 0;
}
/*
* Fix sconfig's bus width according to at_hdmac.
* 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2.
*/
static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
{
switch (addr_width) {
case DMA_SLAVE_BUSWIDTH_2_BYTES:
return 1;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
return 2;
default:
/* For 1 byte width or fallback */
return 0;
}
}
/*-- Controller ------------------------------------------------------*/
/**
* struct at_dma - internal representation of an Atmel HDMA Controller
* @dma_device: dmaengine dma_device object members
* @atdma_devtype: identifier of DMA controller compatibility
* @ch_regs: memory mapped register base
* @clk: dma controller clock
* @save_imr: interrupt mask register that is saved on suspend/resume cycle
* @all_chan_mask: all channels availlable in a mask
* @lli_pool: hw lli table
* @chan: channels table to store at_dma_chan structures
*/
struct at_dma {
struct dma_device dma_device;
void __iomem *regs;
struct clk *clk;
u32 save_imr;
u8 all_chan_mask;
struct dma_pool *lli_pool;
struct dma_pool *memset_pool;
/* AT THE END channels table */
struct at_dma_chan chan[];
};
#define dma_readl(atdma, name) \
__raw_readl((atdma)->regs + AT_DMA_##name)
#define dma_writel(atdma, name, val) \
__raw_writel((val), (atdma)->regs + AT_DMA_##name)
static inline struct at_desc *to_atdma_desc(struct dma_async_tx_descriptor *t)
{
return container_of(t, struct at_desc, vd.tx);
}
static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *chan)
{
return container_of(chan, struct at_dma_chan, vc.chan);
}
static inline struct at_dma *to_at_dma(struct dma_device *ddev)
{
return container_of(ddev, struct at_dma, dma_device);
}
/*-- Helper functions ------------------------------------------------*/
static struct device *chan2dev(struct dma_chan *chan)
{
return &chan->dev->device;
}
#if defined(VERBOSE_DEBUG)
static void vdbg_dump_regs(struct at_dma_chan *atchan)
{
struct at_dma *atdma = to_at_dma(atchan->vc.chan.device);
dev_err(chan2dev(&atchan->vc.chan),
" channel %d : imr = 0x%x, chsr = 0x%x\n",
atchan->vc.chan.chan_id,
dma_readl(atdma, EBCIMR),
dma_readl(atdma, CHSR));
dev_err(chan2dev(&atchan->vc.chan),
" channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n",
channel_readl(atchan, SADDR),
channel_readl(atchan, DADDR),
channel_readl(atchan, CTRLA),
channel_readl(atchan, CTRLB),
channel_readl(atchan, CFG),
channel_readl(atchan, DSCR));
}
#else
static void vdbg_dump_regs(struct at_dma_chan *atchan) {}
#endif
static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
{
dev_crit(chan2dev(&atchan->vc.chan),
"desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n",
&lli->saddr, &lli->daddr,
lli->ctrla, lli->ctrlb, &lli->dscr);
}
static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on)
{
u32 ebci;
/* enable interrupts on buffer transfer completion & error */
ebci = AT_DMA_BTC(chan_id)
| AT_DMA_ERR(chan_id);
if (on)
dma_writel(atdma, EBCIER, ebci);
else
dma_writel(atdma, EBCIDR, ebci);
}
static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id)
{
atc_setup_irq(atdma, chan_id, 1);
}
static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id)
{
atc_setup_irq(atdma, chan_id, 0);
}
/**
* atc_chan_is_enabled - test if given channel is enabled
* @atchan: channel we want to test status
*/
static inline int atc_chan_is_enabled(struct at_dma_chan *atchan)
{
struct at_dma *atdma = to_at_dma(atchan->vc.chan.device);
return !!(dma_readl(atdma, CHSR) & atchan->mask);
}
/**
* atc_chan_is_paused - test channel pause/resume status
* @atchan: channel we want to test status
*/
static inline int atc_chan_is_paused(struct at_dma_chan *atchan)
{
return test_bit(ATC_IS_PAUSED, &atchan->status);
}
/**
* atc_chan_is_cyclic - test if given channel has cyclic property set
* @atchan: channel we want to test status
*/
static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan)
{
return test_bit(ATC_IS_CYCLIC, &atchan->status);
}
/**
* set_lli_eol - set end-of-link to descriptor so it will end transfer
* @desc: descriptor, signle or at the end of a chain, to end chain on
* @i: index of the atmel scatter gather entry that is at the end of the chain.
*/
static void set_lli_eol(struct at_desc *desc, unsigned int i)
{
u32 ctrlb = desc->sg[i].lli->ctrlb;
ctrlb &= ~ATC_IEN;
ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS;
desc->sg[i].lli->ctrlb = ctrlb;
desc->sg[i].lli->dscr = 0;
}
#define ATC_DEFAULT_CFG FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO)
#define ATC_DEFAULT_CTRLB (FIELD_PREP(ATC_SIF, AT_DMA_MEM_IF) | \
FIELD_PREP(ATC_DIF, AT_DMA_MEM_IF))
#define ATC_DMA_BUSWIDTHS\
(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\
BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
#define ATC_MAX_DSCR_TRIALS 10
/*
* Initial number of descriptors to allocate for each channel. This could
* be increased during dma usage.
*/
static unsigned int init_nr_desc_per_channel = 64;
module_param(init_nr_desc_per_channel, uint, 0644);
MODULE_PARM_DESC(init_nr_desc_per_channel,
"initial descriptors per channel (default: 64)");
/**
* struct at_dma_platform_data - Controller configuration parameters
* @nr_channels: Number of channels supported by hardware (max 8)
* @cap_mask: dma_capability flags supported by the platform
*/
struct at_dma_platform_data {
unsigned int nr_channels;
dma_cap_mask_t cap_mask;
};
/**
* struct at_dma_slave - Controller-specific information about a slave
* @dma_dev: required DMA master device
* @cfg: Platform-specific initializer for the CFG register
*/
struct at_dma_slave {
struct device *dma_dev;
u32 cfg;
};
static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst,
size_t len)
{
unsigned int width;
if (!((src | dst | len) & 3))
width = 2;
else if (!((src | dst | len) & 1))
width = 1;
else
width = 0;
return width;
}
static void atdma_lli_chain(struct at_desc *desc, unsigned int i)
{
struct atdma_sg *atdma_sg = &desc->sg[i];
if (i)
desc->sg[i - 1].lli->dscr = atdma_sg->lli_phys;
}
/**
* atc_dostart - starts the DMA engine for real
* @atchan: the channel we want to start
*/
static void atc_dostart(struct at_dma_chan *atchan)
{
struct virt_dma_desc *vd = vchan_next_desc(&atchan->vc);
struct at_desc *desc;
if (!vd) {
atchan->desc = NULL;
return;
}
vdbg_dump_regs(atchan);
list_del(&vd->node);
atchan->desc = desc = to_atdma_desc(&vd->tx);
channel_writel(atchan, SADDR, 0);
channel_writel(atchan, DADDR, 0);
channel_writel(atchan, CTRLA, 0);
channel_writel(atchan, CTRLB, 0);
channel_writel(atchan, DSCR, desc->sg[0].lli_phys);
channel_writel(atchan, SPIP,
FIELD_PREP(ATC_SPIP_HOLE, desc->src_hole) |
FIELD_PREP(ATC_SPIP_BOUNDARY, desc->boundary));
channel_writel(atchan, DPIP,
FIELD_PREP(ATC_DPIP_HOLE, desc->dst_hole) |
FIELD_PREP(ATC_DPIP_BOUNDARY, desc->boundary));
/* Don't allow CPU to reorder channel enable. */
wmb();
dma_writel(atchan->atdma, CHER, atchan->mask);
vdbg_dump_regs(atchan);
}
static void atdma_desc_free(struct virt_dma_desc *vd)
{
struct at_dma *atdma = to_at_dma(vd->tx.chan->device);
struct at_desc *desc = to_atdma_desc(&vd->tx);
unsigned int i;
for (i = 0; i < desc->sglen; i++) {
if (desc->sg[i].lli)
dma_pool_free(atdma->lli_pool, desc->sg[i].lli,
desc->sg[i].lli_phys);
}
/* If the transfer was a memset, free our temporary buffer */
if (desc->memset_buffer) {
dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
desc->memset_paddr);
desc->memset_buffer = false;
}
kfree(desc);
}
/**
* atc_calc_bytes_left - calculates the number of bytes left according to the
* value read from CTRLA.
*
* @current_len: the number of bytes left before reading CTRLA
* @ctrla: the value of CTRLA
*/
static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla)
{
u32 btsize = FIELD_GET(ATC_BTSIZE, ctrla);
u32 src_width = FIELD_GET(ATC_SRC_WIDTH, ctrla);
/*
* According to the datasheet, when reading the Control A Register
* (ctrla), the Buffer Transfer Size (btsize) bitfield refers to the
* number of transfers completed on the Source Interface.
* So btsize is always a number of source width transfers.
*/
return current_len - (btsize << src_width);
}
/**
* atc_get_llis_residue - Get residue for a hardware linked list transfer
*
* Calculate the residue by removing the length of the Linked List Item (LLI)
* already transferred from the total length. To get the current LLI we can use
* the value of the channel's DSCR register and compare it against the DSCR
* value of each LLI.
*
* The CTRLA register provides us with the amount of data already read from the
* source for the LLI. So we can compute a more accurate residue by also
* removing the number of bytes corresponding to this amount of data.
*
* However, the DSCR and CTRLA registers cannot be read both atomically. Hence a
* race condition may occur: the first read register may refer to one LLI
* whereas the second read may refer to a later LLI in the list because of the
* DMA transfer progression inbetween the two reads.
*
* One solution could have been to pause the DMA transfer, read the DSCR and
* CTRLA then resume the DMA transfer. Nonetheless, this approach presents some
* drawbacks:
* - If the DMA transfer is paused, RX overruns or TX underruns are more likey
* to occur depending on the system latency. Taking the USART driver as an
* example, it uses a cyclic DMA transfer to read data from the Receive
* Holding Register (RHR) to avoid RX overruns since the RHR is not protected
* by any FIFO on most Atmel SoCs. So pausing the DMA transfer to compute the
* residue would break the USART driver design.
* - The atc_pause() function masks interrupts but we'd rather avoid to do so
* for system latency purpose.
*
* Then we'd rather use another solution: the DSCR is read a first time, the
* CTRLA is read in turn, next the DSCR is read a second time. If the two
* consecutive read values of the DSCR are the same then we assume both refers
* to the very same LLI as well as the CTRLA value read inbetween does. For
* cyclic tranfers, the assumption is that a full loop is "not so fast". If the
* two DSCR values are different, we read again the CTRLA then the DSCR till two
* consecutive read values from DSCR are equal or till the maximum trials is
* reach. This algorithm is very unlikely not to find a stable value for DSCR.
* @atchan: pointer to an atmel hdmac channel.
* @desc: pointer to the descriptor for which the residue is calculated.
* @residue: residue to be set to dma_tx_state.
* Returns 0 on success, -errno otherwise.
*/
static int atc_get_llis_residue(struct at_dma_chan *atchan,
struct at_desc *desc, u32 *residue)
{
u32 len, ctrla, dscr;
unsigned int i;
len = desc->total_len;
dscr = channel_readl(atchan, DSCR);
rmb(); /* ensure DSCR is read before CTRLA */
ctrla = channel_readl(atchan, CTRLA);
for (i = 0; i < ATC_MAX_DSCR_TRIALS; ++i) {
u32 new_dscr;
rmb(); /* ensure DSCR is read after CTRLA */
new_dscr = channel_readl(atchan, DSCR);
/*
* If the DSCR register value has not changed inside the DMA
* controller since the previous read, we assume that both the
* dscr and ctrla values refers to the very same descriptor.
*/
if (likely(new_dscr == dscr))
break;
/*
* DSCR has changed inside the DMA controller, so the previouly
* read value of CTRLA may refer to an already processed
* descriptor hence could be outdated. We need to update ctrla
* to match the current descriptor.
*/
dscr = new_dscr;
rmb(); /* ensure DSCR is read before CTRLA */
ctrla = channel_readl(atchan, CTRLA);
}
if (unlikely(i == ATC_MAX_DSCR_TRIALS))
return -ETIMEDOUT;
/* For the first descriptor we can be more accurate. */
if (desc->sg[0].lli->dscr == dscr) {
*residue = atc_calc_bytes_left(len, ctrla);
return 0;
}
len -= desc->sg[0].len;
for (i = 1; i < desc->sglen; i++) {
if (desc->sg[i].lli && desc->sg[i].lli->dscr == dscr)
break;
len -= desc->sg[i].len;
}
/*
* For the current LLI in the chain we can calculate the remaining bytes
* using the channel's CTRLA register.
*/
*residue = atc_calc_bytes_left(len, ctrla);
return 0;
}
/**
* atc_get_residue - get the number of bytes residue for a cookie.
* The residue is passed by address and updated on success.
* @chan: DMA channel
* @cookie: transaction identifier to check status of
* @residue: residue to be updated.
* Return 0 on success, -errono otherwise.
*/
static int atc_get_residue(struct dma_chan *chan, dma_cookie_t cookie,
u32 *residue)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct virt_dma_desc *vd;
struct at_desc *desc = NULL;
u32 len, ctrla;
vd = vchan_find_desc(&atchan->vc, cookie);
if (vd)
desc = to_atdma_desc(&vd->tx);
else if (atchan->desc && atchan->desc->vd.tx.cookie == cookie)
desc = atchan->desc;
if (!desc)
return -EINVAL;
if (desc->sg[0].lli->dscr)
/* hardware linked list transfer */
return atc_get_llis_residue(atchan, desc, residue);
/* single transfer */
len = desc->total_len;
ctrla = channel_readl(atchan, CTRLA);
*residue = atc_calc_bytes_left(len, ctrla);
return 0;
}
/**
* atc_handle_error - handle errors reported by DMA controller
* @atchan: channel where error occurs.
* @i: channel index
*/
static void atc_handle_error(struct at_dma_chan *atchan, unsigned int i)
{
struct at_desc *desc = atchan->desc;
/* Disable channel on AHB error */
dma_writel(atchan->atdma, CHDR, AT_DMA_RES(i) | atchan->mask);
/*
* KERN_CRITICAL may seem harsh, but since this only happens
* when someone submits a bad physical address in a
* descriptor, we should consider ourselves lucky that the
* controller flagged an error instead of scribbling over
* random memory locations.
*/
dev_crit(chan2dev(&atchan->vc.chan), "Bad descriptor submitted for DMA!\n");
dev_crit(chan2dev(&atchan->vc.chan), "cookie: %d\n",
desc->vd.tx.cookie);
for (i = 0; i < desc->sglen; i++)
atc_dump_lli(atchan, desc->sg[i].lli);
}
static void atdma_handle_chan_done(struct at_dma_chan *atchan, u32 pending,
unsigned int i)
{
struct at_desc *desc;
spin_lock(&atchan->vc.lock);
desc = atchan->desc;
if (desc) {
if (pending & AT_DMA_ERR(i)) {
atc_handle_error(atchan, i);
/* Pretend the descriptor completed successfully */
}
if (atc_chan_is_cyclic(atchan)) {
vchan_cyclic_callback(&desc->vd);
} else {
vchan_cookie_complete(&desc->vd);
atchan->desc = NULL;
if (!(atc_chan_is_enabled(atchan)))
atc_dostart(atchan);
}
}
spin_unlock(&atchan->vc.lock);
}
static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
{
struct at_dma *atdma = dev_id;
struct at_dma_chan *atchan;
int i;
u32 status, pending, imr;
int ret = IRQ_NONE;
do {
imr = dma_readl(atdma, EBCIMR);
status = dma_readl(atdma, EBCISR);
pending = status & imr;
if (!pending)
break;
dev_vdbg(atdma->dma_device.dev,
"interrupt: status = 0x%08x, 0x%08x, 0x%08x\n",
status, imr, pending);
for (i = 0; i < atdma->dma_device.chancnt; i++) {
atchan = &atdma->chan[i];
if (!(pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))))
continue;
atdma_handle_chan_done(atchan, pending, i);
ret = IRQ_HANDLED;
}
} while (pending);
return ret;
}
/*-- DMA Engine API --------------------------------------------------*/
/**
* atc_prep_dma_interleaved - prepare memory to memory interleaved operation
* @chan: the channel to prepare operation on
* @xt: Interleaved transfer template
* @flags: tx descriptor status flags
*/
static struct dma_async_tx_descriptor *
atc_prep_dma_interleaved(struct dma_chan *chan,
struct dma_interleaved_template *xt,
unsigned long flags)
{
struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct data_chunk *first;
struct atdma_sg *atdma_sg;
struct at_desc *desc;
struct at_lli *lli;
size_t xfer_count;
unsigned int dwidth;
u32 ctrla;
u32 ctrlb;
size_t len = 0;
int i;
if (unlikely(!xt || xt->numf != 1 || !xt->frame_size))
return NULL;
first = xt->sgl;
dev_info(chan2dev(chan),
"%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n",
__func__, &xt->src_start, &xt->dst_start, xt->numf,
xt->frame_size, flags);
/*
* The controller can only "skip" X bytes every Y bytes, so we
* need to make sure we are given a template that fit that
* description, ie a template with chunks that always have the
* same size, with the same ICGs.
*/
for (i = 0; i < xt->frame_size; i++) {
struct data_chunk *chunk = xt->sgl + i;
if ((chunk->size != xt->sgl->size) ||
(dmaengine_get_dst_icg(xt, chunk) != dmaengine_get_dst_icg(xt, first)) ||
(dmaengine_get_src_icg(xt, chunk) != dmaengine_get_src_icg(xt, first))) {
dev_err(chan2dev(chan),
"%s: the controller can transfer only identical chunks\n",
__func__);
return NULL;
}
len += chunk->size;
}
dwidth = atc_get_xfer_width(xt->src_start, xt->dst_start, len);
xfer_count = len >> dwidth;
if (xfer_count > ATC_BTSIZE_MAX) {
dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__);
return NULL;
}
ctrla = FIELD_PREP(ATC_SRC_WIDTH, dwidth) |
FIELD_PREP(ATC_DST_WIDTH, dwidth);
ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
ATC_SRC_PIP | ATC_DST_PIP |
FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);
desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC);
if (!desc)
return NULL;
desc->sglen = 1;
atdma_sg = desc->sg;
atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
&atdma_sg->lli_phys);
if (!atdma_sg->lli) {
kfree(desc);
return NULL;
}
lli = atdma_sg->lli;
lli->saddr = xt->src_start;
lli->daddr = xt->dst_start;
lli->ctrla = ctrla | xfer_count;
lli->ctrlb = ctrlb;
desc->boundary = first->size >> dwidth;
desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1;
desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1;
atdma_sg->len = len;
desc->total_len = len;
set_lli_eol(desc, 0);
return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
}
/**
* atc_prep_dma_memcpy - prepare a memcpy operation
* @chan: the channel to prepare operation on
* @dest: operation virtual destination address
* @src: operation virtual source address
* @len: operation length
* @flags: tx descriptor status flags
*/
static struct dma_async_tx_descriptor *
atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t len, unsigned long flags)
{
struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_desc *desc = NULL;
size_t xfer_count;
size_t offset;
size_t sg_len;
unsigned int src_width;
unsigned int dst_width;
unsigned int i;
u32 ctrla;
u32 ctrlb;
dev_dbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n",
&dest, &src, len, flags);
if (unlikely(!len)) {
dev_err(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
return NULL;
}
sg_len = DIV_ROUND_UP(len, ATC_BTSIZE_MAX);
desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
if (!desc)
return NULL;
desc->sglen = sg_len;
ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);
/*
* We can be a lot more clever here, but this should take care
* of the most common optimization.
*/
src_width = dst_width = atc_get_xfer_width(src, dest, len);
ctrla = FIELD_PREP(ATC_SRC_WIDTH, src_width) |
FIELD_PREP(ATC_DST_WIDTH, dst_width);
for (offset = 0, i = 0; offset < len;
offset += xfer_count << src_width, i++) {
struct atdma_sg *atdma_sg = &desc->sg[i];
struct at_lli *lli;
atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
&atdma_sg->lli_phys);
if (!atdma_sg->lli)
goto err_desc_get;
lli = atdma_sg->lli;
xfer_count = min_t(size_t, (len - offset) >> src_width,
ATC_BTSIZE_MAX);
lli->saddr = src + offset;
lli->daddr = dest + offset;
lli->ctrla = ctrla | xfer_count;
lli->ctrlb = ctrlb;
desc->sg[i].len = xfer_count << src_width;
atdma_lli_chain(desc, i);
}
desc->total_len = len;
/* set end-of-link to the last link descriptor of list*/
set_lli_eol(desc, i - 1);
return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
err_desc_get:
atdma_desc_free(&desc->vd);
return NULL;
}
static int atdma_create_memset_lli(struct dma_chan *chan,
struct atdma_sg *atdma_sg,
dma_addr_t psrc, dma_addr_t pdst, size_t len)
{
struct at_dma *atdma = to_at_dma(chan->device);
struct at_lli *lli;
size_t xfer_count;
u32 ctrla = FIELD_PREP(ATC_SRC_WIDTH, 2) | FIELD_PREP(ATC_DST_WIDTH, 2);
u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) |
FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM);
xfer_count = len >> 2;
if (xfer_count > ATC_BTSIZE_MAX) {
dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__);
return -EINVAL;
}
atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT,
&atdma_sg->lli_phys);
if (!atdma_sg->lli)
return -ENOMEM;
lli = atdma_sg->lli;
lli->saddr = psrc;
lli->daddr = pdst;
lli->ctrla = ctrla | xfer_count;
lli->ctrlb = ctrlb;
atdma_sg->len = len;
return 0;
}
/**
* atc_prep_dma_memset - prepare a memcpy operation
* @chan: the channel to prepare operation on
* @dest: operation virtual destination address
* @value: value to set memory buffer to
* @len: operation length
* @flags: tx descriptor status flags
*/
static struct dma_async_tx_descriptor *
atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
size_t len, unsigned long flags)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
struct at_desc *desc;
void __iomem *vaddr;
dma_addr_t paddr;
char fill_pattern;
int ret;
dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__,
&dest, value, len, flags);
if (unlikely(!len)) {
dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);
return NULL;
}
if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n",
__func__);
return NULL;
}
vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr);
if (!vaddr) {
dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
__func__);
return NULL;
}
/* Only the first byte of value is to be used according to dmaengine */
fill_pattern = (char)value;
*(u32*)vaddr = (fill_pattern << 24) |
(fill_pattern << 16) |
(fill_pattern << 8) |
fill_pattern;
desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC);
if (!desc)
goto err_free_buffer;
desc->sglen = 1;
ret = atdma_create_memset_lli(chan, desc->sg, paddr, dest, len);
if (ret)
goto err_free_desc;
desc->memset_paddr = paddr;
desc->memset_vaddr = vaddr;
desc->memset_buffer = true;
desc->total_len = len;
/* set end-of-link on the descriptor */
set_lli_eol(desc, 0);
return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
err_free_desc:
kfree(desc);
err_free_buffer:
dma_pool_free(atdma->memset_pool, vaddr, paddr);
return NULL;
}
static struct dma_async_tx_descriptor *
atc_prep_dma_memset_sg(struct dma_chan *chan,
struct scatterlist *sgl,
unsigned int sg_len, int value,
unsigned long flags)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
struct at_desc *desc;
struct scatterlist *sg;
void __iomem *vaddr;
dma_addr_t paddr;
size_t total_len = 0;
int i;
int ret;
dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
value, sg_len, flags);
if (unlikely(!sgl || !sg_len)) {
dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n",
__func__);
return NULL;
}
vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr);
if (!vaddr) {
dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
__func__);
return NULL;
}
*(u32*)vaddr = value;
desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
if (!desc)
goto err_free_dma_buf;
desc->sglen = sg_len;
for_each_sg(sgl, sg, sg_len, i) {
dma_addr_t dest = sg_dma_address(sg);
size_t len = sg_dma_len(sg);
dev_vdbg(chan2dev(chan), "%s: d%pad, l0x%zx\n",
__func__, &dest, len);
if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
__func__);
goto err_free_desc;
}
ret = atdma_create_memset_lli(chan, &desc->sg[i], paddr, dest,
len);
if (ret)
goto err_free_desc;
atdma_lli_chain(desc, i);
total_len += len;
}
desc->memset_paddr = paddr;
desc->memset_vaddr = vaddr;
desc->memset_buffer = true;
desc->total_len = total_len;
/* set end-of-link on the descriptor */
set_lli_eol(desc, i - 1);
return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
err_free_desc:
atdma_desc_free(&desc->vd);
err_free_dma_buf:
dma_pool_free(atdma->memset_pool, vaddr, paddr);
return NULL;
}
/**
* atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
* @chan: DMA channel
* @sgl: scatterlist to transfer to/from
* @sg_len: number of entries in @scatterlist
* @direction: DMA direction
* @flags: tx descriptor status flags
* @context: transaction context (ignored)
*/
static struct dma_async_tx_descriptor *
atc_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 at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma_slave *atslave = chan->private;
struct dma_slave_config *sconfig = &atchan->dma_sconfig;
struct at_desc *desc;
u32 ctrla;
u32 ctrlb;
dma_addr_t reg;
unsigned int reg_width;
unsigned int mem_width;
unsigned int i;
struct scatterlist *sg;
size_t total_len = 0;
dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n",
sg_len,
direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
flags);
if (unlikely(!atslave || !sg_len)) {
dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n");
return NULL;
}
desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
if (!desc)
return NULL;
desc->sglen = sg_len;
ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst);
ctrlb = ATC_IEN;
switch (direction) {
case DMA_MEM_TO_DEV:
reg_width = convert_buswidth(sconfig->dst_addr_width);
ctrla |= FIELD_PREP(ATC_DST_WIDTH, reg_width);
ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE,
ATC_DST_ADDR_MODE_FIXED) |
FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) |
FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
FIELD_PREP(ATC_SIF, atchan->mem_if) |
FIELD_PREP(ATC_DIF, atchan->per_if);
reg = sconfig->dst_addr;
for_each_sg(sgl, sg, sg_len, i) {
struct atdma_sg *atdma_sg = &desc->sg[i];
struct at_lli *lli;
u32 len;
u32 mem;
atdma_sg->lli = dma_pool_alloc(atdma->lli_pool,
GFP_NOWAIT,
&atdma_sg->lli_phys);
if (!atdma_sg->lli)
goto err_desc_get;
lli = atdma_sg->lli;
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
if (unlikely(!len)) {
dev_dbg(chan2dev(chan),
"prep_slave_sg: sg(%d) data length is zero\n", i);
goto err;
}
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
lli->saddr = mem;
lli->daddr = reg;
lli->ctrla = ctrla |
FIELD_PREP(ATC_SRC_WIDTH, mem_width) |
len >> mem_width;
lli->ctrlb = ctrlb;
atdma_sg->len = len;
total_len += len;
desc->sg[i].len = len;
atdma_lli_chain(desc, i);
}
break;
case DMA_DEV_TO_MEM:
reg_width = convert_buswidth(sconfig->src_addr_width);
ctrla |= FIELD_PREP(ATC_SRC_WIDTH, reg_width);
ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) |
FIELD_PREP(ATC_SRC_ADDR_MODE,
ATC_SRC_ADDR_MODE_FIXED) |
FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
FIELD_PREP(ATC_SIF, atchan->per_if) |
FIELD_PREP(ATC_DIF, atchan->mem_if);
reg = sconfig->src_addr;
for_each_sg(sgl, sg, sg_len, i) {
struct atdma_sg *atdma_sg = &desc->sg[i];
struct at_lli *lli;
u32 len;
u32 mem;
atdma_sg->lli = dma_pool_alloc(atdma->lli_pool,
GFP_NOWAIT,
&atdma_sg->lli_phys);
if (!atdma_sg->lli)
goto err_desc_get;
lli = atdma_sg->lli;
mem = sg_dma_address(sg);
len = sg_dma_len(sg);
if (unlikely(!len)) {
dev_dbg(chan2dev(chan),
"prep_slave_sg: sg(%d) data length is zero\n", i);
goto err;
}
mem_width = 2;
if (unlikely(mem & 3 || len & 3))
mem_width = 0;
lli->saddr = reg;
lli->daddr = mem;
lli->ctrla = ctrla |
FIELD_PREP(ATC_DST_WIDTH, mem_width) |
len >> reg_width;
lli->ctrlb = ctrlb;
desc->sg[i].len = len;
total_len += len;
atdma_lli_chain(desc, i);
}
break;
default:
return NULL;
}
/* set end-of-link to the last link descriptor of list*/
set_lli_eol(desc, i - 1);
desc->total_len = total_len;
return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
err_desc_get:
dev_err(chan2dev(chan), "not enough descriptors available\n");
err:
atdma_desc_free(&desc->vd);
return NULL;
}
/*
* atc_dma_cyclic_check_values
* Check for too big/unaligned periods and unaligned DMA buffer
*/
static int
atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
size_t period_len)
{
if (period_len > (ATC_BTSIZE_MAX << reg_width))
goto err_out;
if (unlikely(period_len & ((1 << reg_width) - 1)))
goto err_out;
if (unlikely(buf_addr & ((1 << reg_width) - 1)))
goto err_out;
return 0;
err_out:
return -EINVAL;
}
/*
* atc_dma_cyclic_fill_desc - Fill one period descriptor
*/
static int
atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
unsigned int i, dma_addr_t buf_addr,
unsigned int reg_width, size_t period_len,
enum dma_transfer_direction direction)
{
struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct dma_slave_config *sconfig = &atchan->dma_sconfig;
struct atdma_sg *atdma_sg = &desc->sg[i];
struct at_lli *lli;
atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_ATOMIC,
&atdma_sg->lli_phys);
if (!atdma_sg->lli)
return -ENOMEM;
lli = atdma_sg->lli;
switch (direction) {
case DMA_MEM_TO_DEV:
lli->saddr = buf_addr + (period_len * i);
lli->daddr = sconfig->dst_addr;
lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
ATC_DST_ADDR_MODE_FIXED) |
FIELD_PREP(ATC_SRC_ADDR_MODE,
ATC_SRC_ADDR_MODE_INCR) |
FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) |
FIELD_PREP(ATC_SIF, atchan->mem_if) |
FIELD_PREP(ATC_DIF, atchan->per_if);
break;
case DMA_DEV_TO_MEM:
lli->saddr = sconfig->src_addr;
lli->daddr = buf_addr + (period_len * i);
lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE,
ATC_DST_ADDR_MODE_INCR) |
FIELD_PREP(ATC_SRC_ADDR_MODE,
ATC_SRC_ADDR_MODE_FIXED) |
FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) |
FIELD_PREP(ATC_SIF, atchan->per_if) |
FIELD_PREP(ATC_DIF, atchan->mem_if);
break;
default:
return -EINVAL;
}
lli->ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) |
FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) |
FIELD_PREP(ATC_DST_WIDTH, reg_width) |
FIELD_PREP(ATC_SRC_WIDTH, reg_width) |
period_len >> reg_width;
desc->sg[i].len = period_len;
return 0;
}
/**
* atc_prep_dma_cyclic - prepare the cyclic DMA transfer
* @chan: the DMA channel to prepare
* @buf_addr: physical DMA address where the buffer starts
* @buf_len: total number of bytes for the entire buffer
* @period_len: number of bytes for each period
* @direction: transfer direction, to or from device
* @flags: tx descriptor status flags
*/
static struct dma_async_tx_descriptor *
atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma_slave *atslave = chan->private;
struct dma_slave_config *sconfig = &atchan->dma_sconfig;
struct at_desc *desc;
unsigned long was_cyclic;
unsigned int reg_width;
unsigned int periods = buf_len / period_len;
unsigned int i;
dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@%pad - %d (%d/%d)\n",
direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE",
&buf_addr,
periods, buf_len, period_len);
if (unlikely(!atslave || !buf_len || !period_len)) {
dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n");
return NULL;
}
was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status);
if (was_cyclic) {
dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n");
return NULL;
}
if (unlikely(!is_slave_direction(direction)))
goto err_out;
if (direction == DMA_MEM_TO_DEV)
reg_width = convert_buswidth(sconfig->dst_addr_width);
else
reg_width = convert_buswidth(sconfig->src_addr_width);
/* Check for too big/unaligned periods and unaligned DMA buffer */
if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
goto err_out;
desc = kzalloc(struct_size(desc, sg, periods), GFP_ATOMIC);
if (!desc)
goto err_out;
desc->sglen = periods;
/* build cyclic linked list */
for (i = 0; i < periods; i++) {
if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr,
reg_width, period_len, direction))
goto err_fill_desc;
atdma_lli_chain(desc, i);
}
desc->total_len = buf_len;
/* lets make a cyclic list */
desc->sg[i - 1].lli->dscr = desc->sg[0].lli_phys;
return vchan_tx_prep(&atchan->vc, &desc->vd, flags);
err_fill_desc:
atdma_desc_free(&desc->vd);
err_out:
clear_bit(ATC_IS_CYCLIC, &atchan->status);
return NULL;
}
static int atc_config(struct dma_chan *chan,
struct dma_slave_config *sconfig)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
dev_vdbg(chan2dev(chan), "%s\n", __func__);
/* Check if it is chan is configured for slave transfers */
if (!chan->private)
return -EINVAL;
memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig));
convert_burst(&atchan->dma_sconfig.src_maxburst);
convert_burst(&atchan->dma_sconfig.dst_maxburst);
return 0;
}
static int atc_pause(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->vc.chan.chan_id;
unsigned long flags;
dev_vdbg(chan2dev(chan), "%s\n", __func__);
spin_lock_irqsave(&atchan->vc.lock, flags);
dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
set_bit(ATC_IS_PAUSED, &atchan->status);
spin_unlock_irqrestore(&atchan->vc.lock, flags);
return 0;
}
static int atc_resume(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->vc.chan.chan_id;
unsigned long flags;
dev_vdbg(chan2dev(chan), "%s\n", __func__);
if (!atc_chan_is_paused(atchan))
return 0;
spin_lock_irqsave(&atchan->vc.lock, flags);
dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
clear_bit(ATC_IS_PAUSED, &atchan->status);
spin_unlock_irqrestore(&atchan->vc.lock, flags);
return 0;
}
static int atc_terminate_all(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->vc.chan.chan_id;
unsigned long flags;
LIST_HEAD(list);
dev_vdbg(chan2dev(chan), "%s\n", __func__);
/*
* This is only called when something went wrong elsewhere, so
* we don't really care about the data. Just disable the
* channel. We still have to poll the channel enable bit due
* to AHB/HSB limitations.
*/
spin_lock_irqsave(&atchan->vc.lock, flags);
/* disabling channel: must also remove suspend state */
dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
/* confirm that this channel is disabled */
while (dma_readl(atdma, CHSR) & atchan->mask)
cpu_relax();
if (atchan->desc) {
vchan_terminate_vdesc(&atchan->desc->vd);
atchan->desc = NULL;
}
vchan_get_all_descriptors(&atchan->vc, &list);
clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);
spin_unlock_irqrestore(&atchan->vc.lock, flags);
vchan_dma_desc_free_list(&atchan->vc, &list);
return 0;
}
/**
* atc_tx_status - poll for transaction completion
* @chan: DMA channel
* @cookie: transaction identifier to check status of
* @txstate: if not %NULL updated with transaction state
*
* If @txstate is passed in, upon return it reflect the driver
* internal state and can be used with dma_async_is_complete() to check
* the status of multiple cookies without re-checking hardware state.
*/
static enum dma_status
atc_tx_status(struct dma_chan *chan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
unsigned long flags;
enum dma_status dma_status;
u32 residue;
int ret;
dma_status = dma_cookie_status(chan, cookie, txstate);
if (dma_status == DMA_COMPLETE || !txstate)
return dma_status;
spin_lock_irqsave(&atchan->vc.lock, flags);
/* Get number of bytes left in the active transactions */
ret = atc_get_residue(chan, cookie, &residue);
spin_unlock_irqrestore(&atchan->vc.lock, flags);
if (unlikely(ret < 0)) {
dev_vdbg(chan2dev(chan), "get residual bytes error\n");
return DMA_ERROR;
} else {
dma_set_residue(txstate, residue);
}
dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %u\n",
dma_status, cookie, residue);
return dma_status;
}
static void atc_issue_pending(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
unsigned long flags;
spin_lock_irqsave(&atchan->vc.lock, flags);
if (vchan_issue_pending(&atchan->vc) && !atchan->desc) {
if (!(atc_chan_is_enabled(atchan)))
atc_dostart(atchan);
}
spin_unlock_irqrestore(&atchan->vc.lock, flags);
}
/**
* atc_alloc_chan_resources - allocate resources for DMA channel
* @chan: allocate descriptor resources for this channel
*
* return - the number of allocated descriptors
*/
static int atc_alloc_chan_resources(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
struct at_dma_slave *atslave;
u32 cfg;
dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
/* ASSERT: channel is idle */
if (atc_chan_is_enabled(atchan)) {
dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
return -EIO;
}
cfg = ATC_DEFAULT_CFG;
atslave = chan->private;
if (atslave) {
/*
* We need controller-specific data to set up slave
* transfers.
*/
BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_device.dev);
/* if cfg configuration specified take it instead of default */
if (atslave->cfg)
cfg = atslave->cfg;
}
/* channel parameters */
channel_writel(atchan, CFG, cfg);
return 0;
}
/**
* atc_free_chan_resources - free all channel resources
* @chan: DMA channel
*/
static void atc_free_chan_resources(struct dma_chan *chan)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
BUG_ON(atc_chan_is_enabled(atchan));
vchan_free_chan_resources(to_virt_chan(chan));
atchan->status = 0;
/*
* Free atslave allocated in at_dma_xlate()
*/
kfree(chan->private);
chan->private = NULL;
dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
}
#ifdef CONFIG_OF
static bool at_dma_filter(struct dma_chan *chan, void *slave)
{
struct at_dma_slave *atslave = slave;
if (atslave->dma_dev == chan->device->dev) {
chan->private = atslave;
return true;
} else {
return false;
}
}
static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
struct of_dma *of_dma)
{
struct dma_chan *chan;
struct at_dma_chan *atchan;
struct at_dma_slave *atslave;
dma_cap_mask_t mask;
unsigned int per_id;
struct platform_device *dmac_pdev;
if (dma_spec->args_count != 2)
return NULL;
dmac_pdev = of_find_device_by_node(dma_spec->np);
if (!dmac_pdev)
return NULL;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
atslave = kmalloc(sizeof(*atslave), GFP_KERNEL);
if (!atslave) {
put_device(&dmac_pdev->dev);
return NULL;
}
atslave->cfg = ATC_DST_H2SEL | ATC_SRC_H2SEL;
/*
* We can fill both SRC_PER and DST_PER, one of these fields will be
* ignored depending on DMA transfer direction.
*/
per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK;
atslave->cfg |= ATC_DST_PER_ID(per_id) | ATC_SRC_PER_ID(per_id);
/*
* We have to translate the value we get from the device tree since
* the half FIFO configuration value had to be 0 to keep backward
* compatibility.
*/
switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) {
case AT91_DMA_CFG_FIFOCFG_ALAP:
atslave->cfg |= FIELD_PREP(ATC_FIFOCFG,
ATC_FIFOCFG_LARGESTBURST);
break;
case AT91_DMA_CFG_FIFOCFG_ASAP:
atslave->cfg |= FIELD_PREP(ATC_FIFOCFG,
ATC_FIFOCFG_ENOUGHSPACE);
break;
case AT91_DMA_CFG_FIFOCFG_HALF:
default:
atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO);
}
atslave->dma_dev = &dmac_pdev->dev;
chan = dma_request_channel(mask, at_dma_filter, atslave);
if (!chan) {
put_device(&dmac_pdev->dev);
kfree(atslave);
return NULL;
}
atchan = to_at_dma_chan(chan);
atchan->per_if = dma_spec->args[0] & 0xff;
atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff;
return chan;
}
#else
static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
struct of_dma *of_dma)
{
return NULL;
}
#endif
/*-- Module Management -----------------------------------------------*/
/* cap_mask is a multi-u32 bitfield, fill it with proper C code. */
static struct at_dma_platform_data at91sam9rl_config = {
.nr_channels = 2,
};
static struct at_dma_platform_data at91sam9g45_config = {
.nr_channels = 8,
};
#if defined(CONFIG_OF)
static const struct of_device_id atmel_dma_dt_ids[] = {
{
.compatible = "atmel,at91sam9rl-dma",
.data = &at91sam9rl_config,
}, {
.compatible = "atmel,at91sam9g45-dma",
.data = &at91sam9g45_config,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
#endif
static const struct platform_device_id atdma_devtypes[] = {
{
.name = "at91sam9rl_dma",
.driver_data = (unsigned long) &at91sam9rl_config,
}, {
.name = "at91sam9g45_dma",
.driver_data = (unsigned long) &at91sam9g45_config,
}, {
/* sentinel */
}
};
static inline const struct at_dma_platform_data * __init at_dma_get_driver_data(
struct platform_device *pdev)
{
if (pdev->dev.of_node) {
const struct of_device_id *match;
match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node);
if (match == NULL)
return NULL;
return match->data;
}
return (struct at_dma_platform_data *)
platform_get_device_id(pdev)->driver_data;
}
/**
* at_dma_off - disable DMA controller
* @atdma: the Atmel HDAMC device
*/
static void at_dma_off(struct at_dma *atdma)
{
dma_writel(atdma, EN, 0);
/* disable all interrupts */
dma_writel(atdma, EBCIDR, -1L);
/* confirm that all channels are disabled */
while (dma_readl(atdma, CHSR) & atdma->all_chan_mask)
cpu_relax();
}
static int __init at_dma_probe(struct platform_device *pdev)
{
struct at_dma *atdma;
int irq;
int err;
int i;
const struct at_dma_platform_data *plat_dat;
/* setup platform data for each SoC */
dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask);
dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask);
dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask);
dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask);
dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask);
dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
/* get DMA parameters from controller type */
plat_dat = at_dma_get_driver_data(pdev);
if (!plat_dat)
return -ENODEV;
atdma = devm_kzalloc(&pdev->dev,
struct_size(atdma, chan, plat_dat->nr_channels),
GFP_KERNEL);
if (!atdma)
return -ENOMEM;
atdma->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(atdma->regs))
return PTR_ERR(atdma->regs);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
/* discover transaction capabilities */
atdma->dma_device.cap_mask = plat_dat->cap_mask;
atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1;
atdma->clk = devm_clk_get(&pdev->dev, "dma_clk");
if (IS_ERR(atdma->clk))
return PTR_ERR(atdma->clk);
err = clk_prepare_enable(atdma->clk);
if (err)
return err;
/* force dma off, just in case */
at_dma_off(atdma);
err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma);
if (err)
goto err_irq;
platform_set_drvdata(pdev, atdma);
/* create a pool of consistent memory blocks for hardware descriptors */
atdma->lli_pool = dma_pool_create("at_hdmac_lli_pool",
&pdev->dev, sizeof(struct at_lli),
4 /* word alignment */, 0);
if (!atdma->lli_pool) {
dev_err(&pdev->dev, "Unable to allocate DMA LLI descriptor pool\n");
err = -ENOMEM;
goto err_desc_pool_create;
}
/* create a pool of consistent memory blocks for memset blocks */
atdma->memset_pool = dma_pool_create("at_hdmac_memset_pool",
&pdev->dev, sizeof(int), 4, 0);
if (!atdma->memset_pool) {
dev_err(&pdev->dev, "No memory for memset dma pool\n");
err = -ENOMEM;
goto err_memset_pool_create;
}
/* clear any pending interrupt */
while (dma_readl(atdma, EBCISR))
cpu_relax();
/* initialize channels related values */
INIT_LIST_HEAD(&atdma->dma_device.channels);
for (i = 0; i < plat_dat->nr_channels; i++) {
struct at_dma_chan *atchan = &atdma->chan[i];
atchan->mem_if = AT_DMA_MEM_IF;
atchan->per_if = AT_DMA_PER_IF;
atchan->ch_regs = atdma->regs + ch_regs(i);
atchan->mask = 1 << i;
atchan->atdma = atdma;
atchan->vc.desc_free = atdma_desc_free;
vchan_init(&atchan->vc, &atdma->dma_device);
atc_enable_chan_irq(atdma, i);
}
/* set base routines */
atdma->dma_device.device_alloc_chan_resources = atc_alloc_chan_resources;
atdma->dma_device.device_free_chan_resources = atc_free_chan_resources;
atdma->dma_device.device_tx_status = atc_tx_status;
atdma->dma_device.device_issue_pending = atc_issue_pending;
atdma->dma_device.dev = &pdev->dev;
/* set prep routines based on capability */
if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_device.cap_mask))
atdma->dma_device.device_prep_interleaved_dma = atc_prep_dma_interleaved;
if (dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask))
atdma->dma_device.device_prep_dma_memcpy = atc_prep_dma_memcpy;
if (dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask)) {
atdma->dma_device.device_prep_dma_memset = atc_prep_dma_memset;
atdma->dma_device.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
atdma->dma_device.fill_align = DMAENGINE_ALIGN_4_BYTES;
}
if (dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask)) {
atdma->dma_device.device_prep_slave_sg = atc_prep_slave_sg;
/* controller can do slave DMA: can trigger cyclic transfers */
dma_cap_set(DMA_CYCLIC, atdma->dma_device.cap_mask);
atdma->dma_device.device_prep_dma_cyclic = atc_prep_dma_cyclic;
atdma->dma_device.device_config = atc_config;
atdma->dma_device.device_pause = atc_pause;
atdma->dma_device.device_resume = atc_resume;
atdma->dma_device.device_terminate_all = atc_terminate_all;
atdma->dma_device.src_addr_widths = ATC_DMA_BUSWIDTHS;
atdma->dma_device.dst_addr_widths = ATC_DMA_BUSWIDTHS;
atdma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
atdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
}
dma_writel(atdma, EN, AT_DMA_ENABLE);
dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n",
dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask) ? "cpy " : "",
dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask) ? "set " : "",
dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask) ? "slave " : "",
plat_dat->nr_channels);
err = dma_async_device_register(&atdma->dma_device);
if (err) {
dev_err(&pdev->dev, "Unable to register: %d.\n", err);
goto err_dma_async_device_register;
}
/*
* Do not return an error if the dmac node is not present in order to
* not break the existing way of requesting channel with
* dma_request_channel().
*/
if (pdev->dev.of_node) {
err = of_dma_controller_register(pdev->dev.of_node,
at_dma_xlate, atdma);
if (err) {
dev_err(&pdev->dev, "could not register of_dma_controller\n");
goto err_of_dma_controller_register;
}
}
return 0;
err_of_dma_controller_register:
dma_async_device_unregister(&atdma->dma_device);
err_dma_async_device_register:
dma_pool_destroy(atdma->memset_pool);
err_memset_pool_create:
dma_pool_destroy(atdma->lli_pool);
err_desc_pool_create:
free_irq(platform_get_irq(pdev, 0), atdma);
err_irq:
clk_disable_unprepare(atdma->clk);
return err;
}
static void at_dma_remove(struct platform_device *pdev)
{
struct at_dma *atdma = platform_get_drvdata(pdev);
struct dma_chan *chan, *_chan;
at_dma_off(atdma);
if (pdev->dev.of_node)
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&atdma->dma_device);
dma_pool_destroy(atdma->memset_pool);
dma_pool_destroy(atdma->lli_pool);
free_irq(platform_get_irq(pdev, 0), atdma);
list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
/* Disable interrupts */
atc_disable_chan_irq(atdma, chan->chan_id);
list_del(&chan->device_node);
}
clk_disable_unprepare(atdma->clk);
}
static void at_dma_shutdown(struct platform_device *pdev)
{
struct at_dma *atdma = platform_get_drvdata(pdev);
at_dma_off(platform_get_drvdata(pdev));
clk_disable_unprepare(atdma->clk);
}
static int at_dma_prepare(struct device *dev)
{
struct at_dma *atdma = dev_get_drvdata(dev);
struct dma_chan *chan, *_chan;
list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
struct at_dma_chan *atchan = to_at_dma_chan(chan);
/* wait for transaction completion (except in cyclic case) */
if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan))
return -EAGAIN;
}
return 0;
}
static void atc_suspend_cyclic(struct at_dma_chan *atchan)
{
struct dma_chan *chan = &atchan->vc.chan;
/* Channel should be paused by user
* do it anyway even if it is not done already */
if (!atc_chan_is_paused(atchan)) {
dev_warn(chan2dev(chan),
"cyclic channel not paused, should be done by channel user\n");
atc_pause(chan);
}
/* now preserve additional data for cyclic operations */
/* next descriptor address in the cyclic list */
atchan->save_dscr = channel_readl(atchan, DSCR);
vdbg_dump_regs(atchan);
}
static int at_dma_suspend_noirq(struct device *dev)
{
struct at_dma *atdma = dev_get_drvdata(dev);
struct dma_chan *chan, *_chan;
/* preserve data */
list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
struct at_dma_chan *atchan = to_at_dma_chan(chan);
if (atc_chan_is_cyclic(atchan))
atc_suspend_cyclic(atchan);
atchan->save_cfg = channel_readl(atchan, CFG);
}
atdma->save_imr = dma_readl(atdma, EBCIMR);
/* disable DMA controller */
at_dma_off(atdma);
clk_disable_unprepare(atdma->clk);
return 0;
}
static void atc_resume_cyclic(struct at_dma_chan *atchan)
{
struct at_dma *atdma = to_at_dma(atchan->vc.chan.device);
/* restore channel status for cyclic descriptors list:
* next descriptor in the cyclic list at the time of suspend */
channel_writel(atchan, SADDR, 0);
channel_writel(atchan, DADDR, 0);
channel_writel(atchan, CTRLA, 0);
channel_writel(atchan, CTRLB, 0);
channel_writel(atchan, DSCR, atchan->save_dscr);
dma_writel(atdma, CHER, atchan->mask);
/* channel pause status should be removed by channel user
* We cannot take the initiative to do it here */
vdbg_dump_regs(atchan);
}
static int at_dma_resume_noirq(struct device *dev)
{
struct at_dma *atdma = dev_get_drvdata(dev);
struct dma_chan *chan, *_chan;
/* bring back DMA controller */
clk_prepare_enable(atdma->clk);
dma_writel(atdma, EN, AT_DMA_ENABLE);
/* clear any pending interrupt */
while (dma_readl(atdma, EBCISR))
cpu_relax();
/* restore saved data */
dma_writel(atdma, EBCIER, atdma->save_imr);
list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
device_node) {
struct at_dma_chan *atchan = to_at_dma_chan(chan);
channel_writel(atchan, CFG, atchan->save_cfg);
if (atc_chan_is_cyclic(atchan))
atc_resume_cyclic(atchan);
}
return 0;
}
static const struct dev_pm_ops __maybe_unused at_dma_dev_pm_ops = {
.prepare = at_dma_prepare,
.suspend_noirq = at_dma_suspend_noirq,
.resume_noirq = at_dma_resume_noirq,
};
static struct platform_driver at_dma_driver = {
.remove_new = at_dma_remove,
.shutdown = at_dma_shutdown,
.id_table = atdma_devtypes,
.driver = {
.name = "at_hdmac",
.pm = pm_ptr(&at_dma_dev_pm_ops),
.of_match_table = of_match_ptr(atmel_dma_dt_ids),
},
};
static int __init at_dma_init(void)
{
return platform_driver_probe(&at_dma_driver, at_dma_probe);
}
subsys_initcall(at_dma_init);
static void __exit at_dma_exit(void)
{
platform_driver_unregister(&at_dma_driver);
}
module_exit(at_dma_exit);
MODULE_DESCRIPTION("Atmel AHB DMA Controller driver");
MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at_hdmac");
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