diff options
Diffstat (limited to 'drivers/dma/at_xdmac.c')
| -rw-r--r-- | drivers/dma/at_xdmac.c | 2162 |
1 files changed, 2162 insertions, 0 deletions
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c new file mode 100644 index 000000000..861be862a --- /dev/null +++ b/drivers/dma/at_xdmac.c @@ -0,0 +1,2162 @@ +// 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_MASK GENMASK(28, 27) +#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; + u32 save_gs; + struct dma_pool *at_xdmac_desc_pool; + struct at_xdmac_chan chan[]; +}; + + +/* ----- Descriptors ----- */ + +/* Linked List Descriptor */ +struct at_xdmac_lld { + u32 mbr_nda; /* Next Descriptor Member */ + u32 mbr_ubc; /* Microblock Control Member */ + u32 mbr_sa; /* Source Address Member */ + u32 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); + + /* 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_CNDC_NDVIEW_MASK) == 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); + + list_add_tail(&desc->xfer_node, &atchan->xfers_list); + spin_unlock_irqrestore(&atchan->lock, irqflags); + + dev_vdbg(chan2dev(tx->chan), "%s: atchan 0x%p, add desc 0x%p to xfers_list\n", + __func__, atchan, desc); + + 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_tail_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_tail_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); + if (!first) + return NULL; + + /* 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) { + if (first) + list_splice_tail_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_tail_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_tail_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, *iter; + 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(iter, _desc, descs_list, desc_node) { + dwidth = at_xdmac_get_dwidth(iter->lld.mbr_cfg); + residue -= (iter->lld.mbr_ubc & 0xffffff) << dwidth; + if ((iter->lld.mbr_nda & 0xfffffffc) == cur_nda) { + desc = iter; + 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; +} + +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; + + spin_lock_irq(&atchan->lock); + if (list_empty(&atchan->xfers_list)) { + spin_unlock_irq(&atchan->lock); + return; + } + desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc, + xfer_node); + spin_unlock_irq(&atchan->lock); + 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(struct tasklet_struct *t) +{ + struct at_xdmac_chan *atchan = from_tasklet(atchan, t, tasklet); + 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; + dma_cookie_complete(txd); + /* Remove the transfer from the transfer list. */ + list_del(&desc->xfer_node); + spin_unlock_irq(&atchan->lock); + + if (txd->flags & DMA_PREP_INTERRUPT) + dmaengine_desc_get_callback_invoke(txd, NULL); + + dma_run_dependencies(txd); + + spin_lock_irq(&atchan->lock); + /* Move the xfer descriptors into the free descriptors list. */ + list_splice_tail_init(&desc->descs_list, + &atchan->free_descs_list); + 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__); + + 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) { + list_del(&desc->xfer_node); + list_splice_tail_init(&desc->descs_list, + &atchan->free_descs_list); + } + + 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) { + if (i == 0) { + dev_warn(chan2dev(chan), + "can't allocate any descriptors\n"); + return -EIO; + } + 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); + atxdmac->save_gs = at_xdmac_read(atxdmac, AT_XDMAC_GS); + + 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(); + if (atxdmac->save_gs & atchan->mask) + 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_setup(&atchan->tasklet, at_xdmac_tasklet); + + /* 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"); |