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linux/drivers/dma/at_xdmac.c
Gustavo A. R. Silva d9fd428a30 dmaengine: at_xdmac: Replace zero-length array with flexible-array 
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Ludovic Desroches<ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200507190046.GA15298@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-05-13 20:25:41 +05:30

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for the Atmel Extensible DMA Controller (aka XDMAC on AT91 systems)
*
* Copyright (C) 2014 Atmel Corporation
*
* Author: Ludovic Desroches <ludovic.desroches@atmel.com>
*/
#include <asm/barrier.h>
#include <dt-bindings/dma/at91.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of_dma.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include "dmaengine.h"
/* Global registers */
#define AT_XDMAC_GTYPE 0x00 /* Global Type Register */
#define AT_XDMAC_NB_CH(i) (((i) & 0x1F) + 1) /* Number of Channels Minus One */
#define AT_XDMAC_FIFO_SZ(i) (((i) >> 5) & 0x7FF) /* Number of Bytes */
#define AT_XDMAC_NB_REQ(i) ((((i) >> 16) & 0x3F) + 1) /* Number of Peripheral Requests Minus One */
#define AT_XDMAC_GCFG 0x04 /* Global Configuration Register */
#define AT_XDMAC_GWAC 0x08 /* Global Weighted Arbiter Configuration Register */
#define AT_XDMAC_GIE 0x0C /* Global Interrupt Enable Register */
#define AT_XDMAC_GID 0x10 /* Global Interrupt Disable Register */
#define AT_XDMAC_GIM 0x14 /* Global Interrupt Mask Register */
#define AT_XDMAC_GIS 0x18 /* Global Interrupt Status Register */
#define AT_XDMAC_GE 0x1C /* Global Channel Enable Register */
#define AT_XDMAC_GD 0x20 /* Global Channel Disable Register */
#define AT_XDMAC_GS 0x24 /* Global Channel Status Register */
#define AT_XDMAC_GRS 0x28 /* Global Channel Read Suspend Register */
#define AT_XDMAC_GWS 0x2C /* Global Write Suspend Register */
#define AT_XDMAC_GRWS 0x30 /* Global Channel Read Write Suspend Register */
#define AT_XDMAC_GRWR 0x34 /* Global Channel Read Write Resume Register */
#define AT_XDMAC_GSWR 0x38 /* Global Channel Software Request Register */
#define AT_XDMAC_GSWS 0x3C /* Global channel Software Request Status Register */
#define AT_XDMAC_GSWF 0x40 /* Global Channel Software Flush Request Register */
#define AT_XDMAC_VERSION 0xFFC /* XDMAC Version Register */
/* Channel relative registers offsets */
#define AT_XDMAC_CIE 0x00 /* Channel Interrupt Enable Register */
#define AT_XDMAC_CIE_BIE BIT(0) /* End of Block Interrupt Enable Bit */
#define AT_XDMAC_CIE_LIE BIT(1) /* End of Linked List Interrupt Enable Bit */
#define AT_XDMAC_CIE_DIE BIT(2) /* End of Disable Interrupt Enable Bit */
#define AT_XDMAC_CIE_FIE BIT(3) /* End of Flush Interrupt Enable Bit */
#define AT_XDMAC_CIE_RBEIE BIT(4) /* Read Bus Error Interrupt Enable Bit */
#define AT_XDMAC_CIE_WBEIE BIT(5) /* Write Bus Error Interrupt Enable Bit */
#define AT_XDMAC_CIE_ROIE BIT(6) /* Request Overflow Interrupt Enable Bit */
#define AT_XDMAC_CID 0x04 /* Channel Interrupt Disable Register */
#define AT_XDMAC_CID_BID BIT(0) /* End of Block Interrupt Disable Bit */
#define AT_XDMAC_CID_LID BIT(1) /* End of Linked List Interrupt Disable Bit */
#define AT_XDMAC_CID_DID BIT(2) /* End of Disable Interrupt Disable Bit */
#define AT_XDMAC_CID_FID BIT(3) /* End of Flush Interrupt Disable Bit */
#define AT_XDMAC_CID_RBEID BIT(4) /* Read Bus Error Interrupt Disable Bit */
#define AT_XDMAC_CID_WBEID BIT(5) /* Write Bus Error Interrupt Disable Bit */
#define AT_XDMAC_CID_ROID BIT(6) /* Request Overflow Interrupt Disable Bit */
#define AT_XDMAC_CIM 0x08 /* Channel Interrupt Mask Register */
#define AT_XDMAC_CIM_BIM BIT(0) /* End of Block Interrupt Mask Bit */
#define AT_XDMAC_CIM_LIM BIT(1) /* End of Linked List Interrupt Mask Bit */
#define AT_XDMAC_CIM_DIM BIT(2) /* End of Disable Interrupt Mask Bit */
#define AT_XDMAC_CIM_FIM BIT(3) /* End of Flush Interrupt Mask Bit */
#define AT_XDMAC_CIM_RBEIM BIT(4) /* Read Bus Error Interrupt Mask Bit */
#define AT_XDMAC_CIM_WBEIM BIT(5) /* Write Bus Error Interrupt Mask Bit */
#define AT_XDMAC_CIM_ROIM BIT(6) /* Request Overflow Interrupt Mask Bit */
#define AT_XDMAC_CIS 0x0C /* Channel Interrupt Status Register */
#define AT_XDMAC_CIS_BIS BIT(0) /* End of Block Interrupt Status Bit */
#define AT_XDMAC_CIS_LIS BIT(1) /* End of Linked List Interrupt Status Bit */
#define AT_XDMAC_CIS_DIS BIT(2) /* End of Disable Interrupt Status Bit */
#define AT_XDMAC_CIS_FIS BIT(3) /* End of Flush Interrupt Status Bit */
#define AT_XDMAC_CIS_RBEIS BIT(4) /* Read Bus Error Interrupt Status Bit */
#define AT_XDMAC_CIS_WBEIS BIT(5) /* Write Bus Error Interrupt Status Bit */
#define AT_XDMAC_CIS_ROIS BIT(6) /* Request Overflow Interrupt Status Bit */
#define AT_XDMAC_CSA 0x10 /* Channel Source Address Register */
#define AT_XDMAC_CDA 0x14 /* Channel Destination Address Register */
#define AT_XDMAC_CNDA 0x18 /* Channel Next Descriptor Address Register */
#define AT_XDMAC_CNDA_NDAIF(i) ((i) & 0x1) /* Channel x Next Descriptor Interface */
#define AT_XDMAC_CNDA_NDA(i) ((i) & 0xfffffffc) /* Channel x Next Descriptor Address */
#define AT_XDMAC_CNDC 0x1C /* Channel Next Descriptor Control Register */
#define AT_XDMAC_CNDC_NDE (0x1 << 0) /* Channel x Next Descriptor Enable */
#define AT_XDMAC_CNDC_NDSUP (0x1 << 1) /* Channel x Next Descriptor Source Update */
#define AT_XDMAC_CNDC_NDDUP (0x1 << 2) /* Channel x Next Descriptor Destination Update */
#define AT_XDMAC_CNDC_NDVIEW_NDV0 (0x0 << 3) /* Channel x Next Descriptor View 0 */
#define AT_XDMAC_CNDC_NDVIEW_NDV1 (0x1 << 3) /* Channel x Next Descriptor View 1 */
#define AT_XDMAC_CNDC_NDVIEW_NDV2 (0x2 << 3) /* Channel x Next Descriptor View 2 */
#define AT_XDMAC_CNDC_NDVIEW_NDV3 (0x3 << 3) /* Channel x Next Descriptor View 3 */
#define AT_XDMAC_CUBC 0x20 /* Channel Microblock Control Register */
#define AT_XDMAC_CBC 0x24 /* Channel Block Control Register */
#define AT_XDMAC_CC 0x28 /* Channel Configuration Register */
#define AT_XDMAC_CC_TYPE (0x1 << 0) /* Channel Transfer Type */
#define AT_XDMAC_CC_TYPE_MEM_TRAN (0x0 << 0) /* Memory to Memory Transfer */
#define AT_XDMAC_CC_TYPE_PER_TRAN (0x1 << 0) /* Peripheral to Memory or Memory to Peripheral Transfer */
#define AT_XDMAC_CC_MBSIZE_MASK (0x3 << 1)
#define AT_XDMAC_CC_MBSIZE_SINGLE (0x0 << 1)
#define AT_XDMAC_CC_MBSIZE_FOUR (0x1 << 1)
#define AT_XDMAC_CC_MBSIZE_EIGHT (0x2 << 1)
#define AT_XDMAC_CC_MBSIZE_SIXTEEN (0x3 << 1)
#define AT_XDMAC_CC_DSYNC (0x1 << 4) /* Channel Synchronization */
#define AT_XDMAC_CC_DSYNC_PER2MEM (0x0 << 4)
#define AT_XDMAC_CC_DSYNC_MEM2PER (0x1 << 4)
#define AT_XDMAC_CC_PROT (0x1 << 5) /* Channel Protection */
#define AT_XDMAC_CC_PROT_SEC (0x0 << 5)
#define AT_XDMAC_CC_PROT_UNSEC (0x1 << 5)
#define AT_XDMAC_CC_SWREQ (0x1 << 6) /* Channel Software Request Trigger */
#define AT_XDMAC_CC_SWREQ_HWR_CONNECTED (0x0 << 6)
#define AT_XDMAC_CC_SWREQ_SWR_CONNECTED (0x1 << 6)
#define AT_XDMAC_CC_MEMSET (0x1 << 7) /* Channel Fill Block of memory */
#define AT_XDMAC_CC_MEMSET_NORMAL_MODE (0x0 << 7)
#define AT_XDMAC_CC_MEMSET_HW_MODE (0x1 << 7)
#define AT_XDMAC_CC_CSIZE(i) ((0x7 & (i)) << 8) /* Channel Chunk Size */
#define AT_XDMAC_CC_DWIDTH_OFFSET 11
#define AT_XDMAC_CC_DWIDTH_MASK (0x3 << AT_XDMAC_CC_DWIDTH_OFFSET)
#define AT_XDMAC_CC_DWIDTH(i) ((0x3 & (i)) << AT_XDMAC_CC_DWIDTH_OFFSET) /* Channel Data Width */
#define AT_XDMAC_CC_DWIDTH_BYTE 0x0
#define AT_XDMAC_CC_DWIDTH_HALFWORD 0x1
#define AT_XDMAC_CC_DWIDTH_WORD 0x2
#define AT_XDMAC_CC_DWIDTH_DWORD 0x3
#define AT_XDMAC_CC_SIF(i) ((0x1 & (i)) << 13) /* Channel Source Interface Identifier */
#define AT_XDMAC_CC_DIF(i) ((0x1 & (i)) << 14) /* Channel Destination Interface Identifier */
#define AT_XDMAC_CC_SAM_MASK (0x3 << 16) /* Channel Source Addressing Mode */
#define AT_XDMAC_CC_SAM_FIXED_AM (0x0 << 16)
#define AT_XDMAC_CC_SAM_INCREMENTED_AM (0x1 << 16)
#define AT_XDMAC_CC_SAM_UBS_AM (0x2 << 16)
#define AT_XDMAC_CC_SAM_UBS_DS_AM (0x3 << 16)
#define AT_XDMAC_CC_DAM_MASK (0x3 << 18) /* Channel Source Addressing Mode */
#define AT_XDMAC_CC_DAM_FIXED_AM (0x0 << 18)
#define AT_XDMAC_CC_DAM_INCREMENTED_AM (0x1 << 18)
#define AT_XDMAC_CC_DAM_UBS_AM (0x2 << 18)
#define AT_XDMAC_CC_DAM_UBS_DS_AM (0x3 << 18)
#define AT_XDMAC_CC_INITD (0x1 << 21) /* Channel Initialization Terminated (read only) */
#define AT_XDMAC_CC_INITD_TERMINATED (0x0 << 21)
#define AT_XDMAC_CC_INITD_IN_PROGRESS (0x1 << 21)
#define AT_XDMAC_CC_RDIP (0x1 << 22) /* Read in Progress (read only) */
#define AT_XDMAC_CC_RDIP_DONE (0x0 << 22)
#define AT_XDMAC_CC_RDIP_IN_PROGRESS (0x1 << 22)
#define AT_XDMAC_CC_WRIP (0x1 << 23) /* Write in Progress (read only) */
#define AT_XDMAC_CC_WRIP_DONE (0x0 << 23)
#define AT_XDMAC_CC_WRIP_IN_PROGRESS (0x1 << 23)
#define AT_XDMAC_CC_PERID(i) (0x7f & (i) << 24) /* Channel Peripheral Identifier */
#define AT_XDMAC_CDS_MSP 0x2C /* Channel Data Stride Memory Set Pattern */
#define AT_XDMAC_CSUS 0x30 /* Channel Source Microblock Stride */
#define AT_XDMAC_CDUS 0x34 /* Channel Destination Microblock Stride */
#define AT_XDMAC_CHAN_REG_BASE 0x50 /* Channel registers base address */
/* Microblock control members */
#define AT_XDMAC_MBR_UBC_UBLEN_MAX 0xFFFFFFUL /* Maximum Microblock Length */
#define AT_XDMAC_MBR_UBC_NDE (0x1 << 24) /* Next Descriptor Enable */
#define AT_XDMAC_MBR_UBC_NSEN (0x1 << 25) /* Next Descriptor Source Update */
#define AT_XDMAC_MBR_UBC_NDEN (0x1 << 26) /* Next Descriptor Destination Update */
#define AT_XDMAC_MBR_UBC_NDV0 (0x0 << 27) /* Next Descriptor View 0 */
#define AT_XDMAC_MBR_UBC_NDV1 (0x1 << 27) /* Next Descriptor View 1 */
#define AT_XDMAC_MBR_UBC_NDV2 (0x2 << 27) /* Next Descriptor View 2 */
#define AT_XDMAC_MBR_UBC_NDV3 (0x3 << 27) /* Next Descriptor View 3 */
#define AT_XDMAC_MAX_CHAN 0x20
#define AT_XDMAC_MAX_CSIZE 16 /* 16 data */
#define AT_XDMAC_MAX_DWIDTH 8 /* 64 bits */
#define AT_XDMAC_RESIDUE_MAX_RETRIES 5
#define AT_XDMAC_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) |\
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
enum atc_status {
AT_XDMAC_CHAN_IS_CYCLIC = 0,
AT_XDMAC_CHAN_IS_PAUSED,
};
/* ----- Channels ----- */
struct at_xdmac_chan {
struct dma_chan chan;
void __iomem *ch_regs;
u32 mask; /* Channel Mask */
u32 cfg; /* Channel Configuration Register */
u8 perid; /* Peripheral ID */
u8 perif; /* Peripheral Interface */
u8 memif; /* Memory Interface */
u32 save_cc;
u32 save_cim;
u32 save_cnda;
u32 save_cndc;
u32 irq_status;
unsigned long status;
struct tasklet_struct tasklet;
struct dma_slave_config sconfig;
spinlock_t lock;
struct list_head xfers_list;
struct list_head free_descs_list;
};
/* ----- Controller ----- */
struct at_xdmac {
struct dma_device dma;
void __iomem *regs;
int irq;
struct clk *clk;
u32 save_gim;
struct dma_pool *at_xdmac_desc_pool;
struct at_xdmac_chan chan[];
};
/* ----- Descriptors ----- */
/* Linked List Descriptor */
struct at_xdmac_lld {
dma_addr_t mbr_nda; /* Next Descriptor Member */
u32 mbr_ubc; /* Microblock Control Member */
dma_addr_t mbr_sa; /* Source Address Member */
dma_addr_t mbr_da; /* Destination Address Member */
u32 mbr_cfg; /* Configuration Register */
u32 mbr_bc; /* Block Control Register */
u32 mbr_ds; /* Data Stride Register */
u32 mbr_sus; /* Source Microblock Stride Register */
u32 mbr_dus; /* Destination Microblock Stride Register */
};
/* 64-bit alignment needed to update CNDA and CUBC registers in an atomic way. */
struct at_xdmac_desc {
struct at_xdmac_lld lld;
enum dma_transfer_direction direction;
struct dma_async_tx_descriptor tx_dma_desc;
struct list_head desc_node;
/* Following members are only used by the first descriptor */
bool active_xfer;
unsigned int xfer_size;
struct list_head descs_list;
struct list_head xfer_node;
} __aligned(sizeof(u64));
static inline void __iomem *at_xdmac_chan_reg_base(struct at_xdmac *atxdmac, unsigned int chan_nb)
{
return atxdmac->regs + (AT_XDMAC_CHAN_REG_BASE + chan_nb * 0x40);
}
#define at_xdmac_read(atxdmac, reg) readl_relaxed((atxdmac)->regs + (reg))
#define at_xdmac_write(atxdmac, reg, value) \
writel_relaxed((value), (atxdmac)->regs + (reg))
#define at_xdmac_chan_read(atchan, reg) readl_relaxed((atchan)->ch_regs + (reg))
#define at_xdmac_chan_write(atchan, reg, value) writel_relaxed((value), (atchan)->ch_regs + (reg))
static inline struct at_xdmac_chan *to_at_xdmac_chan(struct dma_chan *dchan)
{
return container_of(dchan, struct at_xdmac_chan, chan);
}
static struct device *chan2dev(struct dma_chan *chan)
{
return &chan->dev->device;
}
static inline struct at_xdmac *to_at_xdmac(struct dma_device *ddev)
{
return container_of(ddev, struct at_xdmac, dma);
}
static inline struct at_xdmac_desc *txd_to_at_desc(struct dma_async_tx_descriptor *txd)
{
return container_of(txd, struct at_xdmac_desc, tx_dma_desc);
}
static inline int at_xdmac_chan_is_cyclic(struct at_xdmac_chan *atchan)
{
return test_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status);
}
static inline int at_xdmac_chan_is_paused(struct at_xdmac_chan *atchan)
{
return test_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
}
static inline int at_xdmac_csize(u32 maxburst)
{
int csize;
csize = ffs(maxburst) - 1;
if (csize > 4)
csize = -EINVAL;
return csize;
};
static inline bool at_xdmac_chan_is_peripheral_xfer(u32 cfg)
{
return cfg & AT_XDMAC_CC_TYPE_PER_TRAN;
}
static inline u8 at_xdmac_get_dwidth(u32 cfg)
{
return (cfg & AT_XDMAC_CC_DWIDTH_MASK) >> AT_XDMAC_CC_DWIDTH_OFFSET;
};
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)");
static bool at_xdmac_chan_is_enabled(struct at_xdmac_chan *atchan)
{
return at_xdmac_chan_read(atchan, AT_XDMAC_GS) & atchan->mask;
}
static void at_xdmac_off(struct at_xdmac *atxdmac)
{
at_xdmac_write(atxdmac, AT_XDMAC_GD, -1L);
/* Wait that all chans are disabled. */
while (at_xdmac_read(atxdmac, AT_XDMAC_GS))
cpu_relax();
at_xdmac_write(atxdmac, AT_XDMAC_GID, -1L);
}
/* Call with lock hold. */
static void at_xdmac_start_xfer(struct at_xdmac_chan *atchan,
struct at_xdmac_desc *first)
{
struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
u32 reg;
dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, first);
if (at_xdmac_chan_is_enabled(atchan))
return;
/* Set transfer as active to not try to start it again. */
first->active_xfer = true;
/* Tell xdmac where to get the first descriptor. */
reg = AT_XDMAC_CNDA_NDA(first->tx_dma_desc.phys)
| AT_XDMAC_CNDA_NDAIF(atchan->memif);
at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, reg);
/*
* When doing non cyclic transfer we need to use the next
* descriptor view 2 since some fields of the configuration register
* depend on transfer size and src/dest addresses.
*/
if (at_xdmac_chan_is_cyclic(atchan))
reg = AT_XDMAC_CNDC_NDVIEW_NDV1;
else if (first->lld.mbr_ubc & AT_XDMAC_MBR_UBC_NDV3)
reg = AT_XDMAC_CNDC_NDVIEW_NDV3;
else
reg = AT_XDMAC_CNDC_NDVIEW_NDV2;
/*
* Even if the register will be updated from the configuration in the
* descriptor when using view 2 or higher, the PROT bit won't be set
* properly. This bit can be modified only by using the channel
* configuration register.
*/
at_xdmac_chan_write(atchan, AT_XDMAC_CC, first->lld.mbr_cfg);
reg |= AT_XDMAC_CNDC_NDDUP
| AT_XDMAC_CNDC_NDSUP
| AT_XDMAC_CNDC_NDE;
at_xdmac_chan_write(atchan, AT_XDMAC_CNDC, reg);
dev_vdbg(chan2dev(&atchan->chan),
"%s: CC=0x%08x CNDA=0x%08x, CNDC=0x%08x, CSA=0x%08x, CDA=0x%08x, CUBC=0x%08x\n",
__func__, at_xdmac_chan_read(atchan, AT_XDMAC_CC),
at_xdmac_chan_read(atchan, AT_XDMAC_CNDA),
at_xdmac_chan_read(atchan, AT_XDMAC_CNDC),
at_xdmac_chan_read(atchan, AT_XDMAC_CSA),
at_xdmac_chan_read(atchan, AT_XDMAC_CDA),
at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
at_xdmac_chan_write(atchan, AT_XDMAC_CID, 0xffffffff);
reg = AT_XDMAC_CIE_RBEIE | AT_XDMAC_CIE_WBEIE;
/*
* Request Overflow Error is only for peripheral synchronized transfers
*/
if (at_xdmac_chan_is_peripheral_xfer(first->lld.mbr_cfg))
reg |= AT_XDMAC_CIE_ROIE;
/*
* There is no end of list when doing cyclic dma, we need to get
* an interrupt after each periods.
*/
if (at_xdmac_chan_is_cyclic(atchan))
at_xdmac_chan_write(atchan, AT_XDMAC_CIE,
reg | AT_XDMAC_CIE_BIE);
else
at_xdmac_chan_write(atchan, AT_XDMAC_CIE,
reg | AT_XDMAC_CIE_LIE);
at_xdmac_write(atxdmac, AT_XDMAC_GIE, atchan->mask);
dev_vdbg(chan2dev(&atchan->chan),
"%s: enable channel (0x%08x)\n", __func__, atchan->mask);
wmb();
at_xdmac_write(atxdmac, AT_XDMAC_GE, atchan->mask);
dev_vdbg(chan2dev(&atchan->chan),
"%s: CC=0x%08x CNDA=0x%08x, CNDC=0x%08x, CSA=0x%08x, CDA=0x%08x, CUBC=0x%08x\n",
__func__, at_xdmac_chan_read(atchan, AT_XDMAC_CC),
at_xdmac_chan_read(atchan, AT_XDMAC_CNDA),
at_xdmac_chan_read(atchan, AT_XDMAC_CNDC),
at_xdmac_chan_read(atchan, AT_XDMAC_CSA),
at_xdmac_chan_read(atchan, AT_XDMAC_CDA),
at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
}
static dma_cookie_t at_xdmac_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct at_xdmac_desc *desc = txd_to_at_desc(tx);
struct at_xdmac_chan *atchan = to_at_xdmac_chan(tx->chan);
dma_cookie_t cookie;
unsigned long irqflags;
spin_lock_irqsave(&atchan->lock, irqflags);
cookie = dma_cookie_assign(tx);
dev_vdbg(chan2dev(tx->chan), "%s: atchan 0x%p, add desc 0x%p to xfers_list\n",
__func__, atchan, desc);
list_add_tail(&desc->xfer_node, &atchan->xfers_list);
if (list_is_singular(&atchan->xfers_list))
at_xdmac_start_xfer(atchan, desc);
spin_unlock_irqrestore(&atchan->lock, irqflags);
return cookie;
}
static struct at_xdmac_desc *at_xdmac_alloc_desc(struct dma_chan *chan,
gfp_t gfp_flags)
{
struct at_xdmac_desc *desc;
struct at_xdmac *atxdmac = to_at_xdmac(chan->device);
dma_addr_t phys;
desc = dma_pool_zalloc(atxdmac->at_xdmac_desc_pool, gfp_flags, &phys);
if (desc) {
INIT_LIST_HEAD(&desc->descs_list);
dma_async_tx_descriptor_init(&desc->tx_dma_desc, chan);
desc->tx_dma_desc.tx_submit = at_xdmac_tx_submit;
desc->tx_dma_desc.phys = phys;
}
return desc;
}
static void at_xdmac_init_used_desc(struct at_xdmac_desc *desc)
{
memset(&desc->lld, 0, sizeof(desc->lld));
INIT_LIST_HEAD(&desc->descs_list);
desc->direction = DMA_TRANS_NONE;
desc->xfer_size = 0;
desc->active_xfer = false;
}
/* Call must be protected by lock. */
static struct at_xdmac_desc *at_xdmac_get_desc(struct at_xdmac_chan *atchan)
{
struct at_xdmac_desc *desc;
if (list_empty(&atchan->free_descs_list)) {
desc = at_xdmac_alloc_desc(&atchan->chan, GFP_NOWAIT);
} else {
desc = list_first_entry(&atchan->free_descs_list,
struct at_xdmac_desc, desc_node);
list_del(&desc->desc_node);
at_xdmac_init_used_desc(desc);
}
return desc;
}
static void at_xdmac_queue_desc(struct dma_chan *chan,
struct at_xdmac_desc *prev,
struct at_xdmac_desc *desc)
{
if (!prev || !desc)
return;
prev->lld.mbr_nda = desc->tx_dma_desc.phys;
prev->lld.mbr_ubc |= AT_XDMAC_MBR_UBC_NDE;
dev_dbg(chan2dev(chan), "%s: chain lld: prev=0x%p, mbr_nda=%pad\n",
__func__, prev, &prev->lld.mbr_nda);
}
static inline void at_xdmac_increment_block_count(struct dma_chan *chan,
struct at_xdmac_desc *desc)
{
if (!desc)
return;
desc->lld.mbr_bc++;
dev_dbg(chan2dev(chan),
"%s: incrementing the block count of the desc 0x%p\n",
__func__, desc);
}
static struct dma_chan *at_xdmac_xlate(struct of_phandle_args *dma_spec,
struct of_dma *of_dma)
{
struct at_xdmac *atxdmac = of_dma->of_dma_data;
struct at_xdmac_chan *atchan;
struct dma_chan *chan;
struct device *dev = atxdmac->dma.dev;
if (dma_spec->args_count != 1) {
dev_err(dev, "dma phandler args: bad number of args\n");
return NULL;
}
chan = dma_get_any_slave_channel(&atxdmac->dma);
if (!chan) {
dev_err(dev, "can't get a dma channel\n");
return NULL;
}
atchan = to_at_xdmac_chan(chan);
atchan->memif = AT91_XDMAC_DT_GET_MEM_IF(dma_spec->args[0]);
atchan->perif = AT91_XDMAC_DT_GET_PER_IF(dma_spec->args[0]);
atchan->perid = AT91_XDMAC_DT_GET_PERID(dma_spec->args[0]);
dev_dbg(dev, "chan dt cfg: memif=%u perif=%u perid=%u\n",
atchan->memif, atchan->perif, atchan->perid);
return chan;
}
static int at_xdmac_compute_chan_conf(struct dma_chan *chan,
enum dma_transfer_direction direction)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
int csize, dwidth;
if (direction == DMA_DEV_TO_MEM) {
atchan->cfg =
AT91_XDMAC_DT_PERID(atchan->perid)
| AT_XDMAC_CC_DAM_INCREMENTED_AM
| AT_XDMAC_CC_SAM_FIXED_AM
| AT_XDMAC_CC_DIF(atchan->memif)
| AT_XDMAC_CC_SIF(atchan->perif)
| AT_XDMAC_CC_SWREQ_HWR_CONNECTED
| AT_XDMAC_CC_DSYNC_PER2MEM
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_PER_TRAN;
csize = ffs(atchan->sconfig.src_maxburst) - 1;
if (csize < 0) {
dev_err(chan2dev(chan), "invalid src maxburst value\n");
return -EINVAL;
}
atchan->cfg |= AT_XDMAC_CC_CSIZE(csize);
dwidth = ffs(atchan->sconfig.src_addr_width) - 1;
if (dwidth < 0) {
dev_err(chan2dev(chan), "invalid src addr width value\n");
return -EINVAL;
}
atchan->cfg |= AT_XDMAC_CC_DWIDTH(dwidth);
} else if (direction == DMA_MEM_TO_DEV) {
atchan->cfg =
AT91_XDMAC_DT_PERID(atchan->perid)
| AT_XDMAC_CC_DAM_FIXED_AM
| AT_XDMAC_CC_SAM_INCREMENTED_AM
| AT_XDMAC_CC_DIF(atchan->perif)
| AT_XDMAC_CC_SIF(atchan->memif)
| AT_XDMAC_CC_SWREQ_HWR_CONNECTED
| AT_XDMAC_CC_DSYNC_MEM2PER
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_PER_TRAN;
csize = ffs(atchan->sconfig.dst_maxburst) - 1;
if (csize < 0) {
dev_err(chan2dev(chan), "invalid src maxburst value\n");
return -EINVAL;
}
atchan->cfg |= AT_XDMAC_CC_CSIZE(csize);
dwidth = ffs(atchan->sconfig.dst_addr_width) - 1;
if (dwidth < 0) {
dev_err(chan2dev(chan), "invalid dst addr width value\n");
return -EINVAL;
}
atchan->cfg |= AT_XDMAC_CC_DWIDTH(dwidth);
}
dev_dbg(chan2dev(chan), "%s: cfg=0x%08x\n", __func__, atchan->cfg);
return 0;
}
/*
* Only check that maxburst and addr width values are supported by the
* the controller but not that the configuration is good to perform the
* transfer since we don't know the direction at this stage.
*/
static int at_xdmac_check_slave_config(struct dma_slave_config *sconfig)
{
if ((sconfig->src_maxburst > AT_XDMAC_MAX_CSIZE)
|| (sconfig->dst_maxburst > AT_XDMAC_MAX_CSIZE))
return -EINVAL;
if ((sconfig->src_addr_width > AT_XDMAC_MAX_DWIDTH)
|| (sconfig->dst_addr_width > AT_XDMAC_MAX_DWIDTH))
return -EINVAL;
return 0;
}
static int at_xdmac_set_slave_config(struct dma_chan *chan,
struct dma_slave_config *sconfig)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
if (at_xdmac_check_slave_config(sconfig)) {
dev_err(chan2dev(chan), "invalid slave configuration\n");
return -EINVAL;
}
memcpy(&atchan->sconfig, sconfig, sizeof(atchan->sconfig));
return 0;
}
static struct dma_async_tx_descriptor *
at_xdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *first = NULL, *prev = NULL;
struct scatterlist *sg;
int i;
unsigned int xfer_size = 0;
unsigned long irqflags;
struct dma_async_tx_descriptor *ret = NULL;
if (!sgl)
return NULL;
if (!is_slave_direction(direction)) {
dev_err(chan2dev(chan), "invalid DMA direction\n");
return NULL;
}
dev_dbg(chan2dev(chan), "%s: sg_len=%d, dir=%s, flags=0x%lx\n",
__func__, sg_len,
direction == DMA_MEM_TO_DEV ? "to device" : "from device",
flags);
/* Protect dma_sconfig field that can be modified by set_slave_conf. */
spin_lock_irqsave(&atchan->lock, irqflags);
if (at_xdmac_compute_chan_conf(chan, direction))
goto spin_unlock;
/* Prepare descriptors. */
for_each_sg(sgl, sg, sg_len, i) {
struct at_xdmac_desc *desc = NULL;
u32 len, mem, dwidth, fixed_dwidth;
len = sg_dma_len(sg);
mem = sg_dma_address(sg);
if (unlikely(!len)) {
dev_err(chan2dev(chan), "sg data length is zero\n");
goto spin_unlock;
}
dev_dbg(chan2dev(chan), "%s: * sg%d len=%u, mem=0x%08x\n",
__func__, i, len, mem);
desc = at_xdmac_get_desc(atchan);
if (!desc) {
dev_err(chan2dev(chan), "can't get descriptor\n");
if (first)
list_splice_init(&first->descs_list, &atchan->free_descs_list);
goto spin_unlock;
}
/* Linked list descriptor setup. */
if (direction == DMA_DEV_TO_MEM) {
desc->lld.mbr_sa = atchan->sconfig.src_addr;
desc->lld.mbr_da = mem;
} else {
desc->lld.mbr_sa = mem;
desc->lld.mbr_da = atchan->sconfig.dst_addr;
}
dwidth = at_xdmac_get_dwidth(atchan->cfg);
fixed_dwidth = IS_ALIGNED(len, 1 << dwidth)
? dwidth
: AT_XDMAC_CC_DWIDTH_BYTE;
desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV2 /* next descriptor view */
| AT_XDMAC_MBR_UBC_NDEN /* next descriptor dst parameter update */
| AT_XDMAC_MBR_UBC_NSEN /* next descriptor src parameter update */
| (len >> fixed_dwidth); /* microblock length */
desc->lld.mbr_cfg = (atchan->cfg & ~AT_XDMAC_CC_DWIDTH_MASK) |
AT_XDMAC_CC_DWIDTH(fixed_dwidth);
dev_dbg(chan2dev(chan),
"%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n",
__func__, &desc->lld.mbr_sa, &desc->lld.mbr_da, desc->lld.mbr_ubc);
/* Chain lld. */
if (prev)
at_xdmac_queue_desc(chan, prev, desc);
prev = desc;
if (!first)
first = desc;
dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
__func__, desc, first);
list_add_tail(&desc->desc_node, &first->descs_list);
xfer_size += len;
}
first->tx_dma_desc.flags = flags;
first->xfer_size = xfer_size;
first->direction = direction;
ret = &first->tx_dma_desc;
spin_unlock:
spin_unlock_irqrestore(&atchan->lock, irqflags);
return ret;
}
static struct dma_async_tx_descriptor *
at_xdmac_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_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *first = NULL, *prev = NULL;
unsigned int periods = buf_len / period_len;
int i;
unsigned long irqflags;
dev_dbg(chan2dev(chan), "%s: buf_addr=%pad, buf_len=%zd, period_len=%zd, dir=%s, flags=0x%lx\n",
__func__, &buf_addr, buf_len, period_len,
direction == DMA_MEM_TO_DEV ? "mem2per" : "per2mem", flags);
if (!is_slave_direction(direction)) {
dev_err(chan2dev(chan), "invalid DMA direction\n");
return NULL;
}
if (test_and_set_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status)) {
dev_err(chan2dev(chan), "channel currently used\n");
return NULL;
}
if (at_xdmac_compute_chan_conf(chan, direction))
return NULL;
for (i = 0; i < periods; i++) {
struct at_xdmac_desc *desc = NULL;
spin_lock_irqsave(&atchan->lock, irqflags);
desc = at_xdmac_get_desc(atchan);
if (!desc) {
dev_err(chan2dev(chan), "can't get descriptor\n");
if (first)
list_splice_init(&first->descs_list, &atchan->free_descs_list);
spin_unlock_irqrestore(&atchan->lock, irqflags);
return NULL;
}
spin_unlock_irqrestore(&atchan->lock, irqflags);
dev_dbg(chan2dev(chan),
"%s: desc=0x%p, tx_dma_desc.phys=%pad\n",
__func__, desc, &desc->tx_dma_desc.phys);
if (direction == DMA_DEV_TO_MEM) {
desc->lld.mbr_sa = atchan->sconfig.src_addr;
desc->lld.mbr_da = buf_addr + i * period_len;
} else {
desc->lld.mbr_sa = buf_addr + i * period_len;
desc->lld.mbr_da = atchan->sconfig.dst_addr;
}
desc->lld.mbr_cfg = atchan->cfg;
desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV1
| AT_XDMAC_MBR_UBC_NDEN
| AT_XDMAC_MBR_UBC_NSEN
| period_len >> at_xdmac_get_dwidth(desc->lld.mbr_cfg);
dev_dbg(chan2dev(chan),
"%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n",
__func__, &desc->lld.mbr_sa, &desc->lld.mbr_da, desc->lld.mbr_ubc);
/* Chain lld. */
if (prev)
at_xdmac_queue_desc(chan, prev, desc);
prev = desc;
if (!first)
first = desc;
dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
__func__, desc, first);
list_add_tail(&desc->desc_node, &first->descs_list);
}
at_xdmac_queue_desc(chan, prev, first);
first->tx_dma_desc.flags = flags;
first->xfer_size = buf_len;
first->direction = direction;
return &first->tx_dma_desc;
}
static inline u32 at_xdmac_align_width(struct dma_chan *chan, dma_addr_t addr)
{
u32 width;
/*
* Check address alignment to select the greater data width we
* can use.
*
* Some XDMAC implementations don't provide dword transfer, in
* this case selecting dword has the same behavior as
* selecting word transfers.
*/
if (!(addr & 7)) {
width = AT_XDMAC_CC_DWIDTH_DWORD;
dev_dbg(chan2dev(chan), "%s: dwidth: double word\n", __func__);
} else if (!(addr & 3)) {
width = AT_XDMAC_CC_DWIDTH_WORD;
dev_dbg(chan2dev(chan), "%s: dwidth: word\n", __func__);
} else if (!(addr & 1)) {
width = AT_XDMAC_CC_DWIDTH_HALFWORD;
dev_dbg(chan2dev(chan), "%s: dwidth: half word\n", __func__);
} else {
width = AT_XDMAC_CC_DWIDTH_BYTE;
dev_dbg(chan2dev(chan), "%s: dwidth: byte\n", __func__);
}
return width;
}
static struct at_xdmac_desc *
at_xdmac_interleaved_queue_desc(struct dma_chan *chan,
struct at_xdmac_chan *atchan,
struct at_xdmac_desc *prev,
dma_addr_t src, dma_addr_t dst,
struct dma_interleaved_template *xt,
struct data_chunk *chunk)
{
struct at_xdmac_desc *desc;
u32 dwidth;
unsigned long flags;
size_t ublen;
/*
* WARNING: The channel configuration is set here since there is no
* dmaengine_slave_config call in this case. Moreover we don't know the
* direction, it involves we can't dynamically set the source and dest
* interface so we have to use the same one. Only interface 0 allows EBI
* access. Hopefully we can access DDR through both ports (at least on
* SAMA5D4x), so we can use the same interface for source and dest,
* that solves the fact we don't know the direction.
* ERRATA: Even if useless for memory transfers, the PERID has to not
* match the one of another channel. If not, it could lead to spurious
* flag status.
*/
u32 chan_cc = AT_XDMAC_CC_PERID(0x3f)
| AT_XDMAC_CC_DIF(0)
| AT_XDMAC_CC_SIF(0)
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_MEM_TRAN;
dwidth = at_xdmac_align_width(chan, src | dst | chunk->size);
if (chunk->size >= (AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth)) {
dev_dbg(chan2dev(chan),
"%s: chunk too big (%zu, max size %lu)...\n",
__func__, chunk->size,
AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth);
return NULL;
}
if (prev)
dev_dbg(chan2dev(chan),
"Adding items at the end of desc 0x%p\n", prev);
if (xt->src_inc) {
if (xt->src_sgl)
chan_cc |= AT_XDMAC_CC_SAM_UBS_AM;
else
chan_cc |= AT_XDMAC_CC_SAM_INCREMENTED_AM;
}
if (xt->dst_inc) {
if (xt->dst_sgl)
chan_cc |= AT_XDMAC_CC_DAM_UBS_AM;
else
chan_cc |= AT_XDMAC_CC_DAM_INCREMENTED_AM;
}
spin_lock_irqsave(&atchan->lock, flags);
desc = at_xdmac_get_desc(atchan);
spin_unlock_irqrestore(&atchan->lock, flags);
if (!desc) {
dev_err(chan2dev(chan), "can't get descriptor\n");
return NULL;
}
chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);
ublen = chunk->size >> dwidth;
desc->lld.mbr_sa = src;
desc->lld.mbr_da = dst;
desc->lld.mbr_sus = dmaengine_get_src_icg(xt, chunk);
desc->lld.mbr_dus = dmaengine_get_dst_icg(xt, chunk);
desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3
| AT_XDMAC_MBR_UBC_NDEN
| AT_XDMAC_MBR_UBC_NSEN
| ublen;
desc->lld.mbr_cfg = chan_cc;
dev_dbg(chan2dev(chan),
"%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x, mbr_cfg=0x%08x\n",
__func__, &desc->lld.mbr_sa, &desc->lld.mbr_da,
desc->lld.mbr_ubc, desc->lld.mbr_cfg);
/* Chain lld. */
if (prev)
at_xdmac_queue_desc(chan, prev, desc);
return desc;
}
static struct dma_async_tx_descriptor *
at_xdmac_prep_interleaved(struct dma_chan *chan,
struct dma_interleaved_template *xt,
unsigned long flags)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *prev = NULL, *first = NULL;
dma_addr_t dst_addr, src_addr;
size_t src_skip = 0, dst_skip = 0, len = 0;
struct data_chunk *chunk;
int i;
if (!xt || !xt->numf || (xt->dir != DMA_MEM_TO_MEM))
return NULL;
/*
* TODO: Handle the case where we have to repeat a chain of
* descriptors...
*/
if ((xt->numf > 1) && (xt->frame_size > 1))
return NULL;
dev_dbg(chan2dev(chan), "%s: src=%pad, dest=%pad, numf=%zu, frame_size=%zu, flags=0x%lx\n",
__func__, &xt->src_start, &xt->dst_start, xt->numf,
xt->frame_size, flags);
src_addr = xt->src_start;
dst_addr = xt->dst_start;
if (xt->numf > 1) {
first = at_xdmac_interleaved_queue_desc(chan, atchan,
NULL,
src_addr, dst_addr,
xt, xt->sgl);
/* Length of the block is (BLEN+1) microblocks. */
for (i = 0; i < xt->numf - 1; i++)
at_xdmac_increment_block_count(chan, first);
dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
__func__, first, first);
list_add_tail(&first->desc_node, &first->descs_list);
} else {
for (i = 0; i < xt->frame_size; i++) {
size_t src_icg = 0, dst_icg = 0;
struct at_xdmac_desc *desc;
chunk = xt->sgl + i;
dst_icg = dmaengine_get_dst_icg(xt, chunk);
src_icg = dmaengine_get_src_icg(xt, chunk);
src_skip = chunk->size + src_icg;
dst_skip = chunk->size + dst_icg;
dev_dbg(chan2dev(chan),
"%s: chunk size=%zu, src icg=%zu, dst icg=%zu\n",
__func__, chunk->size, src_icg, dst_icg);
desc = at_xdmac_interleaved_queue_desc(chan, atchan,
prev,
src_addr, dst_addr,
xt, chunk);
if (!desc) {
list_splice_init(&first->descs_list,
&atchan->free_descs_list);
return NULL;
}
if (!first)
first = desc;
dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
__func__, desc, first);
list_add_tail(&desc->desc_node, &first->descs_list);
if (xt->src_sgl)
src_addr += src_skip;
if (xt->dst_sgl)
dst_addr += dst_skip;
len += chunk->size;
prev = desc;
}
}
first->tx_dma_desc.cookie = -EBUSY;
first->tx_dma_desc.flags = flags;
first->xfer_size = len;
return &first->tx_dma_desc;
}
static struct dma_async_tx_descriptor *
at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t len, unsigned long flags)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *first = NULL, *prev = NULL;
size_t remaining_size = len, xfer_size = 0, ublen;
dma_addr_t src_addr = src, dst_addr = dest;
u32 dwidth;
/*
* WARNING: We don't know the direction, it involves we can't
* dynamically set the source and dest interface so we have to use the
* same one. Only interface 0 allows EBI access. Hopefully we can
* access DDR through both ports (at least on SAMA5D4x), so we can use
* the same interface for source and dest, that solves the fact we
* don't know the direction.
* ERRATA: Even if useless for memory transfers, the PERID has to not
* match the one of another channel. If not, it could lead to spurious
* flag status.
*/
u32 chan_cc = AT_XDMAC_CC_PERID(0x3f)
| AT_XDMAC_CC_DAM_INCREMENTED_AM
| AT_XDMAC_CC_SAM_INCREMENTED_AM
| AT_XDMAC_CC_DIF(0)
| AT_XDMAC_CC_SIF(0)
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_TYPE_MEM_TRAN;
unsigned long irqflags;
dev_dbg(chan2dev(chan), "%s: src=%pad, dest=%pad, len=%zd, flags=0x%lx\n",
__func__, &src, &dest, len, flags);
if (unlikely(!len))
return NULL;
dwidth = at_xdmac_align_width(chan, src_addr | dst_addr);
/* Prepare descriptors. */
while (remaining_size) {
struct at_xdmac_desc *desc = NULL;
dev_dbg(chan2dev(chan), "%s: remaining_size=%zu\n", __func__, remaining_size);
spin_lock_irqsave(&atchan->lock, irqflags);
desc = at_xdmac_get_desc(atchan);
spin_unlock_irqrestore(&atchan->lock, irqflags);
if (!desc) {
dev_err(chan2dev(chan), "can't get descriptor\n");
if (first)
list_splice_init(&first->descs_list, &atchan->free_descs_list);
return NULL;
}
/* Update src and dest addresses. */
src_addr += xfer_size;
dst_addr += xfer_size;
if (remaining_size >= AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth)
xfer_size = AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth;
else
xfer_size = remaining_size;
dev_dbg(chan2dev(chan), "%s: xfer_size=%zu\n", __func__, xfer_size);
/* Check remaining length and change data width if needed. */
dwidth = at_xdmac_align_width(chan,
src_addr | dst_addr | xfer_size);
chan_cc &= ~AT_XDMAC_CC_DWIDTH_MASK;
chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);
ublen = xfer_size >> dwidth;
remaining_size -= xfer_size;
desc->lld.mbr_sa = src_addr;
desc->lld.mbr_da = dst_addr;
desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV2
| AT_XDMAC_MBR_UBC_NDEN
| AT_XDMAC_MBR_UBC_NSEN
| ublen;
desc->lld.mbr_cfg = chan_cc;
dev_dbg(chan2dev(chan),
"%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x, mbr_cfg=0x%08x\n",
__func__, &desc->lld.mbr_sa, &desc->lld.mbr_da, desc->lld.mbr_ubc, desc->lld.mbr_cfg);
/* Chain lld. */
if (prev)
at_xdmac_queue_desc(chan, prev, desc);
prev = desc;
if (!first)
first = desc;
dev_dbg(chan2dev(chan), "%s: add desc 0x%p to descs_list 0x%p\n",
__func__, desc, first);
list_add_tail(&desc->desc_node, &first->descs_list);
}
first->tx_dma_desc.flags = flags;
first->xfer_size = len;
return &first->tx_dma_desc;
}
static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan,
struct at_xdmac_chan *atchan,
dma_addr_t dst_addr,
size_t len,
int value)
{
struct at_xdmac_desc *desc;
unsigned long flags;
size_t ublen;
u32 dwidth;
/*
* WARNING: The channel configuration is set here since there is no
* dmaengine_slave_config call in this case. Moreover we don't know the
* direction, it involves we can't dynamically set the source and dest
* interface so we have to use the same one. Only interface 0 allows EBI
* access. Hopefully we can access DDR through both ports (at least on
* SAMA5D4x), so we can use the same interface for source and dest,
* that solves the fact we don't know the direction.
* ERRATA: Even if useless for memory transfers, the PERID has to not
* match the one of another channel. If not, it could lead to spurious
* flag status.
*/
u32 chan_cc = AT_XDMAC_CC_PERID(0x3f)
| AT_XDMAC_CC_DAM_UBS_AM
| AT_XDMAC_CC_SAM_INCREMENTED_AM
| AT_XDMAC_CC_DIF(0)
| AT_XDMAC_CC_SIF(0)
| AT_XDMAC_CC_MBSIZE_SIXTEEN
| AT_XDMAC_CC_MEMSET_HW_MODE
| AT_XDMAC_CC_TYPE_MEM_TRAN;
dwidth = at_xdmac_align_width(chan, dst_addr);
if (len >= (AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth)) {
dev_err(chan2dev(chan),
"%s: Transfer too large, aborting...\n",
__func__);
return NULL;
}
spin_lock_irqsave(&atchan->lock, flags);
desc = at_xdmac_get_desc(atchan);
spin_unlock_irqrestore(&atchan->lock, flags);
if (!desc) {
dev_err(chan2dev(chan), "can't get descriptor\n");
return NULL;
}
chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);
ublen = len >> dwidth;
desc->lld.mbr_da = dst_addr;
desc->lld.mbr_ds = value;
desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3
| AT_XDMAC_MBR_UBC_NDEN
| AT_XDMAC_MBR_UBC_NSEN
| ublen;
desc->lld.mbr_cfg = chan_cc;
dev_dbg(chan2dev(chan),
"%s: lld: mbr_da=%pad, mbr_ds=0x%08x, mbr_ubc=0x%08x, mbr_cfg=0x%08x\n",
__func__, &desc->lld.mbr_da, desc->lld.mbr_ds, desc->lld.mbr_ubc,
desc->lld.mbr_cfg);
return desc;
}
static struct dma_async_tx_descriptor *
at_xdmac_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
size_t len, unsigned long flags)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *desc;
dev_dbg(chan2dev(chan), "%s: dest=%pad, len=%zu, pattern=0x%x, flags=0x%lx\n",
__func__, &dest, len, value, flags);
if (unlikely(!len))
return NULL;
desc = at_xdmac_memset_create_desc(chan, atchan, dest, len, value);
list_add_tail(&desc->desc_node, &desc->descs_list);
desc->tx_dma_desc.cookie = -EBUSY;
desc->tx_dma_desc.flags = flags;
desc->xfer_size = len;
return &desc->tx_dma_desc;
}
static struct dma_async_tx_descriptor *
at_xdmac_prep_dma_memset_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, int value,
unsigned long flags)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *desc, *pdesc = NULL,
*ppdesc = NULL, *first = NULL;
struct scatterlist *sg, *psg = NULL, *ppsg = NULL;
size_t stride = 0, pstride = 0, len = 0;
int i;
if (!sgl)
return NULL;
dev_dbg(chan2dev(chan), "%s: sg_len=%d, value=0x%x, flags=0x%lx\n",
__func__, sg_len, value, flags);
/* Prepare descriptors. */
for_each_sg(sgl, sg, sg_len, i) {
dev_dbg(chan2dev(chan), "%s: dest=%pad, len=%d, pattern=0x%x, flags=0x%lx\n",
__func__, &sg_dma_address(sg), sg_dma_len(sg),
value, flags);
desc = at_xdmac_memset_create_desc(chan, atchan,
sg_dma_address(sg),
sg_dma_len(sg),
value);
if (!desc && first)
list_splice_init(&first->descs_list,
&atchan->free_descs_list);
if (!first)
first = desc;
/* Update our strides */
pstride = stride;
if (psg)
stride = sg_dma_address(sg) -
(sg_dma_address(psg) + sg_dma_len(psg));
/*
* The scatterlist API gives us only the address and
* length of each elements.
*
* Unfortunately, we don't have the stride, which we
* will need to compute.
*
* That make us end up in a situation like this one:
* len stride len stride len
* +-------+ +-------+ +-------+
* | N-2 | | N-1 | | N |
* +-------+ +-------+ +-------+
*
* We need all these three elements (N-2, N-1 and N)
* to actually take the decision on whether we need to
* queue N-1 or reuse N-2.
*
* We will only consider N if it is the last element.
*/
if (ppdesc && pdesc) {
if ((stride == pstride) &&
(sg_dma_len(ppsg) == sg_dma_len(psg))) {
dev_dbg(chan2dev(chan),
"%s: desc 0x%p can be merged with desc 0x%p\n",
__func__, pdesc, ppdesc);
/*
* Increment the block count of the
* N-2 descriptor
*/
at_xdmac_increment_block_count(chan, ppdesc);
ppdesc->lld.mbr_dus = stride;
/*
* Put back the N-1 descriptor in the
* free descriptor list
*/
list_add_tail(&pdesc->desc_node,
&atchan->free_descs_list);
/*
* Make our N-1 descriptor pointer
* point to the N-2 since they were
* actually merged.
*/
pdesc = ppdesc;
/*
* Rule out the case where we don't have
* pstride computed yet (our second sg
* element)
*
* We also want to catch the case where there
* would be a negative stride,
*/
} else if (pstride ||
sg_dma_address(sg) < sg_dma_address(psg)) {
/*
* Queue the N-1 descriptor after the
* N-2
*/
at_xdmac_queue_desc(chan, ppdesc, pdesc);
/*
* Add the N-1 descriptor to the list
* of the descriptors used for this
* transfer
*/
list_add_tail(&desc->desc_node,
&first->descs_list);
dev_dbg(chan2dev(chan),
"%s: add desc 0x%p to descs_list 0x%p\n",
__func__, desc, first);
}
}
/*
* If we are the last element, just see if we have the
* same size than the previous element.
*
* If so, we can merge it with the previous descriptor
* since we don't care about the stride anymore.
*/
if ((i == (sg_len - 1)) &&
sg_dma_len(psg) == sg_dma_len(sg)) {
dev_dbg(chan2dev(chan),
"%s: desc 0x%p can be merged with desc 0x%p\n",
__func__, desc, pdesc);
/*
* Increment the block count of the N-1
* descriptor
*/
at_xdmac_increment_block_count(chan, pdesc);
pdesc->lld.mbr_dus = stride;
/*
* Put back the N descriptor in the free
* descriptor list
*/
list_add_tail(&desc->desc_node,
&atchan->free_descs_list);
}
/* Update our descriptors */
ppdesc = pdesc;
pdesc = desc;
/* Update our scatter pointers */
ppsg = psg;
psg = sg;
len += sg_dma_len(sg);
}
first->tx_dma_desc.cookie = -EBUSY;
first->tx_dma_desc.flags = flags;
first->xfer_size = len;
return &first->tx_dma_desc;
}
static enum dma_status
at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
struct at_xdmac_desc *desc, *_desc;
struct list_head *descs_list;
enum dma_status ret;
int residue, retry;
u32 cur_nda, check_nda, cur_ubc, mask, value;
u8 dwidth = 0;
unsigned long flags;
bool initd;
ret = dma_cookie_status(chan, cookie, txstate);
if (ret == DMA_COMPLETE)
return ret;
if (!txstate)
return ret;
spin_lock_irqsave(&atchan->lock, flags);
desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, xfer_node);
/*
* If the transfer has not been started yet, don't need to compute the
* residue, it's the transfer length.
*/
if (!desc->active_xfer) {
dma_set_residue(txstate, desc->xfer_size);
goto spin_unlock;
}
residue = desc->xfer_size;
/*
* Flush FIFO: only relevant when the transfer is source peripheral
* synchronized. Flush is needed before reading CUBC because data in
* the FIFO are not reported by CUBC. Reporting a residue of the
* transfer length while we have data in FIFO can cause issue.
* Usecase: atmel USART has a timeout which means I have received
* characters but there is no more character received for a while. On
* timeout, it requests the residue. If the data are in the DMA FIFO,
* we will return a residue of the transfer length. It means no data
* received. If an application is waiting for these data, it will hang
* since we won't have another USART timeout without receiving new
* data.
*/
mask = AT_XDMAC_CC_TYPE | AT_XDMAC_CC_DSYNC;
value = AT_XDMAC_CC_TYPE_PER_TRAN | AT_XDMAC_CC_DSYNC_PER2MEM;
if ((desc->lld.mbr_cfg & mask) == value) {
at_xdmac_write(atxdmac, AT_XDMAC_GSWF, atchan->mask);
while (!(at_xdmac_chan_read(atchan, AT_XDMAC_CIS) & AT_XDMAC_CIS_FIS))
cpu_relax();
}
/*
* The easiest way to compute the residue should be to pause the DMA
* but doing this can lead to miss some data as some devices don't
* have FIFO.
* We need to read several registers because:
* - DMA is running therefore a descriptor change is possible while
* reading these registers
* - When the block transfer is done, the value of the CUBC register
* is set to its initial value until the fetch of the next descriptor.
* This value will corrupt the residue calculation so we have to skip
* it.
*
* INITD -------- ------------
* |____________________|
* _______________________ _______________
* NDA @desc2 \/ @desc3
* _______________________/\_______________
* __________ ___________ _______________
* CUBC 0 \/ MAX desc1 \/ MAX desc2
* __________/\___________/\_______________
*
* Since descriptors are aligned on 64 bits, we can assume that
* the update of NDA and CUBC is atomic.
* Memory barriers are used to ensure the read order of the registers.
* A max number of retries is set because unlikely it could never ends.
*/
for (retry = 0; retry < AT_XDMAC_RESIDUE_MAX_RETRIES; retry++) {
check_nda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA) & 0xfffffffc;
rmb();
cur_ubc = at_xdmac_chan_read(atchan, AT_XDMAC_CUBC);
rmb();
initd = !!(at_xdmac_chan_read(atchan, AT_XDMAC_CC) & AT_XDMAC_CC_INITD);
rmb();
cur_nda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA) & 0xfffffffc;
rmb();
if ((check_nda == cur_nda) && initd)
break;
}
if (unlikely(retry >= AT_XDMAC_RESIDUE_MAX_RETRIES)) {
ret = DMA_ERROR;
goto spin_unlock;
}
/*
* Flush FIFO: only relevant when the transfer is source peripheral
* synchronized. Another flush is needed here because CUBC is updated
* when the controller sends the data write command. It can lead to
* report data that are not written in the memory or the device. The
* FIFO flush ensures that data are really written.
*/
if ((desc->lld.mbr_cfg & mask) == value) {
at_xdmac_write(atxdmac, AT_XDMAC_GSWF, atchan->mask);
while (!(at_xdmac_chan_read(atchan, AT_XDMAC_CIS) & AT_XDMAC_CIS_FIS))
cpu_relax();
}
/*
* Remove size of all microblocks already transferred and the current
* one. Then add the remaining size to transfer of the current
* microblock.
*/
descs_list = &desc->descs_list;
list_for_each_entry_safe(desc, _desc, descs_list, desc_node) {
dwidth = at_xdmac_get_dwidth(desc->lld.mbr_cfg);
residue -= (desc->lld.mbr_ubc & 0xffffff) << dwidth;
if ((desc->lld.mbr_nda & 0xfffffffc) == cur_nda)
break;
}
residue += cur_ubc << dwidth;
dma_set_residue(txstate, residue);
dev_dbg(chan2dev(chan),
"%s: desc=0x%p, tx_dma_desc.phys=%pad, tx_status=%d, cookie=%d, residue=%d\n",
__func__, desc, &desc->tx_dma_desc.phys, ret, cookie, residue);
spin_unlock:
spin_unlock_irqrestore(&atchan->lock, flags);
return ret;
}
/* Call must be protected by lock. */
static void at_xdmac_remove_xfer(struct at_xdmac_chan *atchan,
struct at_xdmac_desc *desc)
{
dev_dbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
/*
* Remove the transfer from the transfer list then move the transfer
* descriptors into the free descriptors list.
*/
list_del(&desc->xfer_node);
list_splice_init(&desc->descs_list, &atchan->free_descs_list);
}
static void at_xdmac_advance_work(struct at_xdmac_chan *atchan)
{
struct at_xdmac_desc *desc;
/*
* If channel is enabled, do nothing, advance_work will be triggered
* after the interruption.
*/
if (!at_xdmac_chan_is_enabled(atchan) && !list_empty(&atchan->xfers_list)) {
desc = list_first_entry(&atchan->xfers_list,
struct at_xdmac_desc,
xfer_node);
dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
if (!desc->active_xfer)
at_xdmac_start_xfer(atchan, desc);
}
}
static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
{
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
if (!list_empty(&atchan->xfers_list)) {
desc = list_first_entry(&atchan->xfers_list,
struct at_xdmac_desc, xfer_node);
txd = &desc->tx_dma_desc;
if (txd->flags & DMA_PREP_INTERRUPT)
dmaengine_desc_get_callback_invoke(txd, NULL);
}
}
static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
{
struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
struct at_xdmac_desc *bad_desc;
/*
* The descriptor currently at the head of the active list is
* broken. Since we don't have any way to report errors, we'll
* just have to scream loudly and try to continue with other
* descriptors queued (if any).
*/
if (atchan->irq_status & AT_XDMAC_CIS_RBEIS)
dev_err(chan2dev(&atchan->chan), "read bus error!!!");
if (atchan->irq_status & AT_XDMAC_CIS_WBEIS)
dev_err(chan2dev(&atchan->chan), "write bus error!!!");
if (atchan->irq_status & AT_XDMAC_CIS_ROIS)
dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
spin_lock_irq(&atchan->lock);
/* Channel must be disabled first as it's not done automatically */
at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
cpu_relax();
bad_desc = list_first_entry(&atchan->xfers_list,
struct at_xdmac_desc,
xfer_node);
spin_unlock_irq(&atchan->lock);
/* Print bad descriptor's details if needed */
dev_dbg(chan2dev(&atchan->chan),
"%s: lld: mbr_sa=%pad, mbr_da=%pad, mbr_ubc=0x%08x\n",
__func__, &bad_desc->lld.mbr_sa, &bad_desc->lld.mbr_da,
bad_desc->lld.mbr_ubc);
/* Then continue with usual descriptor management */
}
static void at_xdmac_tasklet(unsigned long data)
{
struct at_xdmac_chan *atchan = (struct at_xdmac_chan *)data;
struct at_xdmac_desc *desc;
u32 error_mask;
dev_dbg(chan2dev(&atchan->chan), "%s: status=0x%08x\n",
__func__, atchan->irq_status);
error_mask = AT_XDMAC_CIS_RBEIS
| AT_XDMAC_CIS_WBEIS
| AT_XDMAC_CIS_ROIS;
if (at_xdmac_chan_is_cyclic(atchan)) {
at_xdmac_handle_cyclic(atchan);
} else if ((atchan->irq_status & AT_XDMAC_CIS_LIS)
|| (atchan->irq_status & error_mask)) {
struct dma_async_tx_descriptor *txd;
if (atchan->irq_status & error_mask)
at_xdmac_handle_error(atchan);
spin_lock_irq(&atchan->lock);
desc = list_first_entry(&atchan->xfers_list,
struct at_xdmac_desc,
xfer_node);
dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
if (!desc->active_xfer) {
dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting");
spin_unlock_irq(&atchan->lock);
return;
}
txd = &desc->tx_dma_desc;
at_xdmac_remove_xfer(atchan, desc);
spin_unlock_irq(&atchan->lock);
dma_cookie_complete(txd);
if (txd->flags & DMA_PREP_INTERRUPT)
dmaengine_desc_get_callback_invoke(txd, NULL);
dma_run_dependencies(txd);
spin_lock_irq(&atchan->lock);
at_xdmac_advance_work(atchan);
spin_unlock_irq(&atchan->lock);
}
}
static irqreturn_t at_xdmac_interrupt(int irq, void *dev_id)
{
struct at_xdmac *atxdmac = (struct at_xdmac *)dev_id;
struct at_xdmac_chan *atchan;
u32 imr, status, pending;
u32 chan_imr, chan_status;
int i, ret = IRQ_NONE;
do {
imr = at_xdmac_read(atxdmac, AT_XDMAC_GIM);
status = at_xdmac_read(atxdmac, AT_XDMAC_GIS);
pending = status & imr;
dev_vdbg(atxdmac->dma.dev,
"%s: status=0x%08x, imr=0x%08x, pending=0x%08x\n",
__func__, status, imr, pending);
if (!pending)
break;
/* We have to find which channel has generated the interrupt. */
for (i = 0; i < atxdmac->dma.chancnt; i++) {
if (!((1 << i) & pending))
continue;
atchan = &atxdmac->chan[i];
chan_imr = at_xdmac_chan_read(atchan, AT_XDMAC_CIM);
chan_status = at_xdmac_chan_read(atchan, AT_XDMAC_CIS);
atchan->irq_status = chan_status & chan_imr;
dev_vdbg(atxdmac->dma.dev,
"%s: chan%d: imr=0x%x, status=0x%x\n",
__func__, i, chan_imr, chan_status);
dev_vdbg(chan2dev(&atchan->chan),
"%s: CC=0x%08x CNDA=0x%08x, CNDC=0x%08x, CSA=0x%08x, CDA=0x%08x, CUBC=0x%08x\n",
__func__,
at_xdmac_chan_read(atchan, AT_XDMAC_CC),
at_xdmac_chan_read(atchan, AT_XDMAC_CNDA),
at_xdmac_chan_read(atchan, AT_XDMAC_CNDC),
at_xdmac_chan_read(atchan, AT_XDMAC_CSA),
at_xdmac_chan_read(atchan, AT_XDMAC_CDA),
at_xdmac_chan_read(atchan, AT_XDMAC_CUBC));
if (atchan->irq_status & (AT_XDMAC_CIS_RBEIS | AT_XDMAC_CIS_WBEIS))
at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
tasklet_schedule(&atchan->tasklet);
ret = IRQ_HANDLED;
}
} while (pending);
return ret;
}
static void at_xdmac_issue_pending(struct dma_chan *chan)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
unsigned long flags;
dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
if (!at_xdmac_chan_is_cyclic(atchan)) {
spin_lock_irqsave(&atchan->lock, flags);
at_xdmac_advance_work(atchan);
spin_unlock_irqrestore(&atchan->lock, flags);
}
return;
}
static int at_xdmac_device_config(struct dma_chan *chan,
struct dma_slave_config *config)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
int ret;
unsigned long flags;
dev_dbg(chan2dev(chan), "%s\n", __func__);
spin_lock_irqsave(&atchan->lock, flags);
ret = at_xdmac_set_slave_config(chan, config);
spin_unlock_irqrestore(&atchan->lock, flags);
return ret;
}
static int at_xdmac_device_pause(struct dma_chan *chan)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
unsigned long flags;
dev_dbg(chan2dev(chan), "%s\n", __func__);
if (test_and_set_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status))
return 0;
spin_lock_irqsave(&atchan->lock, flags);
at_xdmac_write(atxdmac, AT_XDMAC_GRWS, atchan->mask);
while (at_xdmac_chan_read(atchan, AT_XDMAC_CC)
& (AT_XDMAC_CC_WRIP | AT_XDMAC_CC_RDIP))
cpu_relax();
spin_unlock_irqrestore(&atchan->lock, flags);
return 0;
}
static int at_xdmac_device_resume(struct dma_chan *chan)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
unsigned long flags;
dev_dbg(chan2dev(chan), "%s\n", __func__);
spin_lock_irqsave(&atchan->lock, flags);
if (!at_xdmac_chan_is_paused(atchan)) {
spin_unlock_irqrestore(&atchan->lock, flags);
return 0;
}
at_xdmac_write(atxdmac, AT_XDMAC_GRWR, atchan->mask);
clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
spin_unlock_irqrestore(&atchan->lock, flags);
return 0;
}
static int at_xdmac_device_terminate_all(struct dma_chan *chan)
{
struct at_xdmac_desc *desc, *_desc;
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device);
unsigned long flags;
dev_dbg(chan2dev(chan), "%s\n", __func__);
spin_lock_irqsave(&atchan->lock, flags);
at_xdmac_write(atxdmac, AT_XDMAC_GD, atchan->mask);
while (at_xdmac_read(atxdmac, AT_XDMAC_GS) & atchan->mask)
cpu_relax();
/* Cancel all pending transfers. */
list_for_each_entry_safe(desc, _desc, &atchan->xfers_list, xfer_node)
at_xdmac_remove_xfer(atchan, desc);
clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
clear_bit(AT_XDMAC_CHAN_IS_CYCLIC, &atchan->status);
spin_unlock_irqrestore(&atchan->lock, flags);
return 0;
}
static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac_desc *desc;
int i;
if (at_xdmac_chan_is_enabled(atchan)) {
dev_err(chan2dev(chan),
"can't allocate channel resources (channel enabled)\n");
return -EIO;
}
if (!list_empty(&atchan->free_descs_list)) {
dev_err(chan2dev(chan),
"can't allocate channel resources (channel not free from a previous use)\n");
return -EIO;
}
for (i = 0; i < init_nr_desc_per_channel; i++) {
desc = at_xdmac_alloc_desc(chan, GFP_KERNEL);
if (!desc) {
dev_warn(chan2dev(chan),
"only %d descriptors have been allocated\n", i);
break;
}
list_add_tail(&desc->desc_node, &atchan->free_descs_list);
}
dma_cookie_init(chan);
dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);
return i;
}
static void at_xdmac_free_chan_resources(struct dma_chan *chan)
{
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
struct at_xdmac *atxdmac = to_at_xdmac(chan->device);
struct at_xdmac_desc *desc, *_desc;
list_for_each_entry_safe(desc, _desc, &atchan->free_descs_list, desc_node) {
dev_dbg(chan2dev(chan), "%s: freeing descriptor %p\n", __func__, desc);
list_del(&desc->desc_node);
dma_pool_free(atxdmac->at_xdmac_desc_pool, desc, desc->tx_dma_desc.phys);
}
return;
}
#ifdef CONFIG_PM
static int atmel_xdmac_prepare(struct device *dev)
{
struct at_xdmac *atxdmac = dev_get_drvdata(dev);
struct dma_chan *chan, *_chan;
list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels, device_node) {
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
/* Wait for transfer completion, except in cyclic case. */
if (at_xdmac_chan_is_enabled(atchan) && !at_xdmac_chan_is_cyclic(atchan))
return -EAGAIN;
}
return 0;
}
#else
# define atmel_xdmac_prepare NULL
#endif
#ifdef CONFIG_PM_SLEEP
static int atmel_xdmac_suspend(struct device *dev)
{
struct at_xdmac *atxdmac = dev_get_drvdata(dev);
struct dma_chan *chan, *_chan;
list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels, device_node) {
struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
atchan->save_cc = at_xdmac_chan_read(atchan, AT_XDMAC_CC);
if (at_xdmac_chan_is_cyclic(atchan)) {
if (!at_xdmac_chan_is_paused(atchan))
at_xdmac_device_pause(chan);
atchan->save_cim = at_xdmac_chan_read(atchan, AT_XDMAC_CIM);
atchan->save_cnda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA);
atchan->save_cndc = at_xdmac_chan_read(atchan, AT_XDMAC_CNDC);
}
}
atxdmac->save_gim = at_xdmac_read(atxdmac, AT_XDMAC_GIM);
at_xdmac_off(atxdmac);
clk_disable_unprepare(atxdmac->clk);
return 0;
}
static int atmel_xdmac_resume(struct device *dev)
{
struct at_xdmac *atxdmac = dev_get_drvdata(dev);
struct at_xdmac_chan *atchan;
struct dma_chan *chan, *_chan;
int i;
int ret;
ret = clk_prepare_enable(atxdmac->clk);
if (ret)
return ret;
/* Clear pending interrupts. */
for (i = 0; i < atxdmac->dma.chancnt; i++) {
atchan = &atxdmac->chan[i];
while (at_xdmac_chan_read(atchan, AT_XDMAC_CIS))
cpu_relax();
}
at_xdmac_write(atxdmac, AT_XDMAC_GIE, atxdmac->save_gim);
list_for_each_entry_safe(chan, _chan, &atxdmac->dma.channels, device_node) {
atchan = to_at_xdmac_chan(chan);
at_xdmac_chan_write(atchan, AT_XDMAC_CC, atchan->save_cc);
if (at_xdmac_chan_is_cyclic(atchan)) {
if (at_xdmac_chan_is_paused(atchan))
at_xdmac_device_resume(chan);
at_xdmac_chan_write(atchan, AT_XDMAC_CNDA, atchan->save_cnda);
at_xdmac_chan_write(atchan, AT_XDMAC_CNDC, atchan->save_cndc);
at_xdmac_chan_write(atchan, AT_XDMAC_CIE, atchan->save_cim);
wmb();
at_xdmac_write(atxdmac, AT_XDMAC_GE, atchan->mask);
}
}
return 0;
}
#endif /* CONFIG_PM_SLEEP */
static int at_xdmac_probe(struct platform_device *pdev)
{
struct at_xdmac *atxdmac;
int irq, size, nr_channels, i, ret;
void __iomem *base;
u32 reg;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
/*
* Read number of xdmac channels, read helper function can't be used
* since atxdmac is not yet allocated and we need to know the number
* of channels to do the allocation.
*/
reg = readl_relaxed(base + AT_XDMAC_GTYPE);
nr_channels = AT_XDMAC_NB_CH(reg);
if (nr_channels > AT_XDMAC_MAX_CHAN) {
dev_err(&pdev->dev, "invalid number of channels (%u)\n",
nr_channels);
return -EINVAL;
}
size = sizeof(*atxdmac);
size += nr_channels * sizeof(struct at_xdmac_chan);
atxdmac = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
if (!atxdmac) {
dev_err(&pdev->dev, "can't allocate at_xdmac structure\n");
return -ENOMEM;
}
atxdmac->regs = base;
atxdmac->irq = irq;
atxdmac->clk = devm_clk_get(&pdev->dev, "dma_clk");
if (IS_ERR(atxdmac->clk)) {
dev_err(&pdev->dev, "can't get dma_clk\n");
return PTR_ERR(atxdmac->clk);
}
/* Do not use dev res to prevent races with tasklet */
ret = request_irq(atxdmac->irq, at_xdmac_interrupt, 0, "at_xdmac", atxdmac);
if (ret) {
dev_err(&pdev->dev, "can't request irq\n");
return ret;
}
ret = clk_prepare_enable(atxdmac->clk);
if (ret) {
dev_err(&pdev->dev, "can't prepare or enable clock\n");
goto err_free_irq;
}
atxdmac->at_xdmac_desc_pool =
dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
sizeof(struct at_xdmac_desc), 4, 0);
if (!atxdmac->at_xdmac_desc_pool) {
dev_err(&pdev->dev, "no memory for descriptors dma pool\n");
ret = -ENOMEM;
goto err_clk_disable;
}
dma_cap_set(DMA_CYCLIC, atxdmac->dma.cap_mask);
dma_cap_set(DMA_INTERLEAVE, atxdmac->dma.cap_mask);
dma_cap_set(DMA_MEMCPY, atxdmac->dma.cap_mask);
dma_cap_set(DMA_MEMSET, atxdmac->dma.cap_mask);
dma_cap_set(DMA_MEMSET_SG, atxdmac->dma.cap_mask);
dma_cap_set(DMA_SLAVE, atxdmac->dma.cap_mask);
/*
* Without DMA_PRIVATE the driver is not able to allocate more than
* one channel, second allocation fails in private_candidate.
*/
dma_cap_set(DMA_PRIVATE, atxdmac->dma.cap_mask);
atxdmac->dma.dev = &pdev->dev;
atxdmac->dma.device_alloc_chan_resources = at_xdmac_alloc_chan_resources;
atxdmac->dma.device_free_chan_resources = at_xdmac_free_chan_resources;
atxdmac->dma.device_tx_status = at_xdmac_tx_status;
atxdmac->dma.device_issue_pending = at_xdmac_issue_pending;
atxdmac->dma.device_prep_dma_cyclic = at_xdmac_prep_dma_cyclic;
atxdmac->dma.device_prep_interleaved_dma = at_xdmac_prep_interleaved;
atxdmac->dma.device_prep_dma_memcpy = at_xdmac_prep_dma_memcpy;
atxdmac->dma.device_prep_dma_memset = at_xdmac_prep_dma_memset;
atxdmac->dma.device_prep_dma_memset_sg = at_xdmac_prep_dma_memset_sg;
atxdmac->dma.device_prep_slave_sg = at_xdmac_prep_slave_sg;
atxdmac->dma.device_config = at_xdmac_device_config;
atxdmac->dma.device_pause = at_xdmac_device_pause;
atxdmac->dma.device_resume = at_xdmac_device_resume;
atxdmac->dma.device_terminate_all = at_xdmac_device_terminate_all;
atxdmac->dma.src_addr_widths = AT_XDMAC_DMA_BUSWIDTHS;
atxdmac->dma.dst_addr_widths = AT_XDMAC_DMA_BUSWIDTHS;
atxdmac->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
atxdmac->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
/* Disable all chans and interrupts. */
at_xdmac_off(atxdmac);
/* Init channels. */
INIT_LIST_HEAD(&atxdmac->dma.channels);
for (i = 0; i < nr_channels; i++) {
struct at_xdmac_chan *atchan = &atxdmac->chan[i];
atchan->chan.device = &atxdmac->dma;
list_add_tail(&atchan->chan.device_node,
&atxdmac->dma.channels);
atchan->ch_regs = at_xdmac_chan_reg_base(atxdmac, i);
atchan->mask = 1 << i;
spin_lock_init(&atchan->lock);
INIT_LIST_HEAD(&atchan->xfers_list);
INIT_LIST_HEAD(&atchan->free_descs_list);
tasklet_init(&atchan->tasklet, at_xdmac_tasklet,
(unsigned long)atchan);
/* Clear pending interrupts. */
while (at_xdmac_chan_read(atchan, AT_XDMAC_CIS))
cpu_relax();
}
platform_set_drvdata(pdev, atxdmac);
ret = dma_async_device_register(&atxdmac->dma);
if (ret) {
dev_err(&pdev->dev, "fail to register DMA engine device\n");
goto err_clk_disable;
}
ret = of_dma_controller_register(pdev->dev.of_node,
at_xdmac_xlate, atxdmac);
if (ret) {
dev_err(&pdev->dev, "could not register of dma controller\n");
goto err_dma_unregister;
}
dev_info(&pdev->dev, "%d channels, mapped at 0x%p\n",
nr_channels, atxdmac->regs);
return 0;
err_dma_unregister:
dma_async_device_unregister(&atxdmac->dma);
err_clk_disable:
clk_disable_unprepare(atxdmac->clk);
err_free_irq:
free_irq(atxdmac->irq, atxdmac);
return ret;
}
static int at_xdmac_remove(struct platform_device *pdev)
{
struct at_xdmac *atxdmac = (struct at_xdmac *)platform_get_drvdata(pdev);
int i;
at_xdmac_off(atxdmac);
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&atxdmac->dma);
clk_disable_unprepare(atxdmac->clk);
free_irq(atxdmac->irq, atxdmac);
for (i = 0; i < atxdmac->dma.chancnt; i++) {
struct at_xdmac_chan *atchan = &atxdmac->chan[i];
tasklet_kill(&atchan->tasklet);
at_xdmac_free_chan_resources(&atchan->chan);
}
return 0;
}
static const struct dev_pm_ops atmel_xdmac_dev_pm_ops = {
.prepare = atmel_xdmac_prepare,
SET_LATE_SYSTEM_SLEEP_PM_OPS(atmel_xdmac_suspend, atmel_xdmac_resume)
};
static const struct of_device_id atmel_xdmac_dt_ids[] = {
{
.compatible = "atmel,sama5d4-dma",
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(of, atmel_xdmac_dt_ids);
static struct platform_driver at_xdmac_driver = {
.probe = at_xdmac_probe,
.remove = at_xdmac_remove,
.driver = {
.name = "at_xdmac",
.of_match_table = of_match_ptr(atmel_xdmac_dt_ids),
.pm = &atmel_xdmac_dev_pm_ops,
}
};
static int __init at_xdmac_init(void)
{
return platform_driver_probe(&at_xdmac_driver, at_xdmac_probe);
}
subsys_initcall(at_xdmac_init);
MODULE_DESCRIPTION("Atmel Extended DMA Controller driver");
MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
MODULE_LICENSE("GPL");
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