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linux/drivers/dma/at_xdmac.c
Maxime Jayat c5637476bb dmaengine: at_xdmac: fix rare residue corruption 
Despite the efforts made to correctly read the NDA and CUBC registers,
the order in which the registers are read could sometimes lead to an
inconsistent state.

Re-using the timeline from the comments, this following timing of
registers reads could lead to reading NDA with value "@desc2" and
CUBC with value "MAX desc1":

 INITD --------                    ------------
              |____________________|
       _______________________  _______________
 NDA       @desc2             \/   @desc3
       _______________________/\_______________
       __________  ___________  _______________
 CUBC       0    \/ MAX desc1 \/  MAX desc2
       __________/\___________/\_______________
        |  |          |  |
Events:(1)(2)        (3)(4)

(1) check_nda = @desc2
(2) initd = 1
(3) cur_ubc = MAX desc1
(4) cur_nda = @desc2

This is allowed by the condition ((check_nda == cur_nda) && initd),
despite cur_ubc and cur_nda being in the precise state we don't want.

This error leads to incorrect residue computation.

Fix it by inversing the order in which CUBC and INITD are read. This
makes sure that NDA and CUBC are always read together either _before_
INITD goes to 0 or _after_ it is back at 1.
The case where NDA is read before INITD is at 0 and CUBC is read after
INITD is back at 1 will be rejected by check_nda and cur_nda being
different.

Fixes: 53398f4888 ("dmaengine: at_xdmac: fix residue corruption")
Cc: stable@vger.kernel.org
Signed-off-by: Maxime Jayat <maxime.jayat@mobile-devices.fr>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2018-03-27 17:33:44 +05:30

2129 lines
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/*
* Driver for the Atmel Extensible DMA Controller (aka XDMAC on AT91 systems)
*
* Copyright (C) 2014 Atmel Corporation
*
* Author: Ludovic Desroches <ludovic.desroches@atmel.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#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;
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[0];
};
/* ----- 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 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 | 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;
unsigned long flags;
spin_lock_irqsave(&atchan->lock, flags);
/*
* 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);
}
spin_unlock_irqrestore(&atchan->lock, flags);
}
static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
{
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
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_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%08lx\n",
__func__, atchan->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->status & AT_XDMAC_CIS_LIS)
|| (atchan->status & error_mask)) {
struct dma_async_tx_descriptor *txd;
if (atchan->status & AT_XDMAC_CIS_RBEIS)
dev_err(chan2dev(&atchan->chan), "read bus error!!!");
if (atchan->status & AT_XDMAC_CIS_WBEIS)
dev_err(chan2dev(&atchan->chan), "write bus error!!!");
if (atchan->status & AT_XDMAC_CIS_ROIS)
dev_err(chan2dev(&atchan->chan), "request overflow error!!!");
spin_lock_bh(&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);
BUG_ON(!desc->active_xfer);
txd = &desc->tx_dma_desc;
at_xdmac_remove_xfer(atchan, desc);
spin_unlock_bh(&atchan->lock);
if (!at_xdmac_chan_is_cyclic(atchan)) {
dma_cookie_complete(txd);
if (txd->flags & DMA_PREP_INTERRUPT)
dmaengine_desc_get_callback_invoke(txd, NULL);
}
dma_run_dependencies(txd);
at_xdmac_advance_work(atchan);
}
}
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->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->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);
dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
if (!at_xdmac_chan_is_cyclic(atchan))
at_xdmac_advance_work(atchan);
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;
unsigned long flags;
spin_lock_irqsave(&atchan->lock, flags);
if (at_xdmac_chan_is_enabled(atchan)) {
dev_err(chan2dev(chan),
"can't allocate channel resources (channel enabled)\n");
i = -EIO;
goto spin_unlock;
}
if (!list_empty(&atchan->free_descs_list)) {
dev_err(chan2dev(chan),
"can't allocate channel resources (channel not free from a previous use)\n");
i = -EIO;
goto spin_unlock;
}
for (i = 0; i < init_nr_desc_per_channel; i++) {
desc = at_xdmac_alloc_desc(chan, GFP_ATOMIC);
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);
spin_unlock:
spin_unlock_irqrestore(&atchan->lock, flags);
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 platform_device *pdev = to_platform_device(dev);
struct at_xdmac *atxdmac = platform_get_drvdata(pdev);
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 platform_device *pdev = to_platform_device(dev);
struct at_xdmac *atxdmac = platform_get_drvdata(pdev);
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 platform_device *pdev = to_platform_device(dev);
struct at_xdmac *atxdmac = platform_get_drvdata(pdev);
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 resource *res;
struct at_xdmac *atxdmac;
int irq, size, nr_channels, i, ret;
void __iomem *base;
u32 reg;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -EINVAL;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
base = devm_ioremap_resource(&pdev->dev, res);
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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