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linux/drivers/dma/at_hdmac.c
Tudor Ambarus ac803b5686 dmaengine: at_hdmac: Convert driver to use virt-dma 
Convert the driver to use the core virt-dma. The driver will be easier to
maintain as it uses the list handling and the tasklet from virt-dma.

With the conversion replace the election of a new transfer in the tasklet
with the election of the new transfer in the interrupt handler. With this
we have a shorter idle window as we remove the scheduling latency of the
tasklet. I chose to do this while doing the conversion to virt-dma,
because if I made a prerequisite patch with the new transfer election in
the irq handler, I would have to duplicate some virt-dma code in the
at_hdmac driver that would end up being removed at the virt-dma conversion
anyway. So do this in a single step.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-33-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2022-11-11 12:15:09 +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_device.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(22, 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_PER_MSB(h) ((0x30U & (h)) >> 4) /* Extract most significant bits of a handshaking identifier */
#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_SRC_PER_ID(id) (FIELD_PREP(ATC_SRC_PER_MSB, (id)) | \
FIELD_PREP(ATC_SRC_PER, (id)))
#define ATC_DST_PER_ID(id) (FIELD_PREP(ATC_DST_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 int 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);
return 0;
}
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 = 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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