| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Nicolas Ferre | 4742 | 49.55% | 27 | 24.77% |
| Tudor-Dan Ambarus | 2516 | 26.29% | 28 | 25.69% |
| Maxime Ripard | 1185 | 12.38% | 5 | 4.59% |
| Ludovic Desroches | 451 | 4.71% | 4 | 3.67% |
| Torsten Fleischer | 244 | 2.55% | 2 | 1.83% |
| Cyrille Pitchen | 66 | 0.69% | 1 | 0.92% |
| Elen Song | 44 | 0.46% | 1 | 0.92% |
| Nikolaus Voss | 33 | 0.34% | 1 | 0.92% |
| yu kuai | 33 | 0.34% | 3 | 2.75% |
| Richard Genoud | 31 | 0.32% | 2 | 1.83% |
| Dan J Williams | 31 | 0.32% | 1 | 0.92% |
| Ben Walker | 30 | 0.31% | 1 | 0.92% |
| Maninder Singh | 22 | 0.23% | 1 | 0.92% |
| Linus Walleij | 20 | 0.21% | 3 | 2.75% |
| Arnd Bergmann | 15 | 0.16% | 1 | 0.92% |
| Andy Shevchenko | 14 | 0.15% | 1 | 0.92% |
| Russell King | 12 | 0.13% | 2 | 1.83% |
| Boris Brezillon | 12 | 0.13% | 1 | 0.92% |
| Vinod Koul | 11 | 0.11% | 3 | 2.75% |
| Peter Rosin | 10 | 0.10% | 2 | 1.83% |
| Gustavo A. R. Silva | 7 | 0.07% | 2 | 1.83% |
| Linus Torvalds | 7 | 0.07% | 1 | 0.92% |
| Alex Bounine | 6 | 0.06% | 1 | 0.92% |
| Wolfram Sang | 6 | 0.06% | 1 | 0.92% |
| Allen Pais | 5 | 0.05% | 1 | 0.92% |
| Peter Ujfalusi | 3 | 0.03% | 1 | 0.92% |
| Uwe Kleine-König | 2 | 0.02% | 1 | 0.92% |
| Tejun Heo | 2 | 0.02% | 1 | 0.92% |
| Lee Jones | 2 | 0.02% | 1 | 0.92% |
| Dave Jiang | 2 | 0.02% | 2 | 1.83% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.92% |
| Alexandre Belloni | 1 | 0.01% | 1 | 0.92% |
| Laurent Pinchart | 1 | 0.01% | 1 | 0.92% |
| Eric Xu | 1 | 0.01% | 1 | 0.92% |
| Joe Perches | 1 | 0.01% | 1 | 0.92% |
| Alexey Dobriyan | 1 | 0.01% | 1 | 0.92% |
| Barry Song | 1 | 0.01% | 1 | 0.92% |
| Total | 9571 | 109 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems) * * Copyright (C) 2008 Atmel Corporation * Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries * * This supports the Atmel AHB DMA Controller found in several Atmel SoCs. * The only Atmel DMA Controller that is not covered by this driver is the one * found on AT91SAM9263. */ #include <dt-bindings/dma/at91.h> #include <linux/bitfield.h> #include <linux/clk.h> #include <linux/dmaengine.h> #include <linux/dmapool.h> #include <linux/dma-mapping.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/of.h> #include <linux/overflow.h> #include <linux/of_device.h> #include <linux/of_dma.h> #include <linux/platform_device.h> #include <linux/slab.h> #include "dmaengine.h" #include "virt-dma.h" /* * Glossary * -------- * * at_hdmac : Name of the ATmel AHB DMA Controller * at_dma_ / atdma : ATmel DMA controller entity related * atc_ / atchan : ATmel DMA Channel entity related */ #define AT_DMA_MAX_NR_CHANNELS 8 /* Global Configuration Register */ #define AT_DMA_GCFG 0x00 #define AT_DMA_IF_BIGEND(i) BIT((i)) /* AHB-Lite Interface i in Big-endian mode */ #define AT_DMA_ARB_CFG BIT(4) /* Arbiter mode. */ /* Controller Enable Register */ #define AT_DMA_EN 0x04 #define AT_DMA_ENABLE BIT(0) /* Software Single Request Register */ #define AT_DMA_SREQ 0x08 #define AT_DMA_SSREQ(x) BIT((x) << 1) /* Request a source single transfer on channel x */ #define AT_DMA_DSREQ(x) BIT(1 + ((x) << 1)) /* Request a destination single transfer on channel x */ /* Software Chunk Transfer Request Register */ #define AT_DMA_CREQ 0x0c #define AT_DMA_SCREQ(x) BIT((x) << 1) /* Request a source chunk transfer on channel x */ #define AT_DMA_DCREQ(x) BIT(1 + ((x) << 1)) /* Request a destination chunk transfer on channel x */ /* Software Last Transfer Flag Register */ #define AT_DMA_LAST 0x10 #define AT_DMA_SLAST(x) BIT((x) << 1) /* This src rq is last tx of buffer on channel x */ #define AT_DMA_DLAST(x) BIT(1 + ((x) << 1)) /* This dst rq is last tx of buffer on channel x */ /* Request Synchronization Register */ #define AT_DMA_SYNC 0x14 #define AT_DMA_SYR(h) BIT((h)) /* Synchronize handshake line h */ /* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */ #define AT_DMA_EBCIER 0x18 /* Enable register */ #define AT_DMA_EBCIDR 0x1c /* Disable register */ #define AT_DMA_EBCIMR 0x20 /* Mask Register */ #define AT_DMA_EBCISR 0x24 /* Status Register */ #define AT_DMA_CBTC_OFFSET 8 #define AT_DMA_ERR_OFFSET 16 #define AT_DMA_BTC(x) BIT((x)) #define AT_DMA_CBTC(x) BIT(AT_DMA_CBTC_OFFSET + (x)) #define AT_DMA_ERR(x) BIT(AT_DMA_ERR_OFFSET + (x)) /* Channel Handler Enable Register */ #define AT_DMA_CHER 0x28 #define AT_DMA_ENA(x) BIT((x)) #define AT_DMA_SUSP(x) BIT(8 + (x)) #define AT_DMA_KEEP(x) BIT(24 + (x)) /* Channel Handler Disable Register */ #define AT_DMA_CHDR 0x2c #define AT_DMA_DIS(x) BIT(x) #define AT_DMA_RES(x) BIT(8 + (x)) /* Channel Handler Status Register */ #define AT_DMA_CHSR 0x30 #define AT_DMA_EMPT(x) BIT(16 + (x)) #define AT_DMA_STAL(x) BIT(24 + (x)) /* Channel registers base address */ #define AT_DMA_CH_REGS_BASE 0x3c #define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */ /* Hardware register offset for each channel */ #define ATC_SADDR_OFFSET 0x00 /* Source Address Register */ #define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */ #define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */ #define ATC_CTRLA_OFFSET 0x0c /* Control A Register */ #define ATC_CTRLB_OFFSET 0x10 /* Control B Register */ #define ATC_CFG_OFFSET 0x14 /* Configuration Register */ #define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */ #define ATC_DPIP_OFFSET 0x1c /* Dst PIP Configuration Register */ /* Bitfield definitions */ /* Bitfields in DSCR */ #define ATC_DSCR_IF GENMASK(1, 0) /* Dsc feched via AHB-Lite Interface */ /* Bitfields in CTRLA */ #define ATC_BTSIZE_MAX GENMASK(15, 0) /* Maximum Buffer Transfer Size */ #define ATC_BTSIZE GENMASK(15, 0) /* Buffer Transfer Size */ #define ATC_SCSIZE GENMASK(18, 16) /* Source Chunk Transfer Size */ #define ATC_DCSIZE GENMASK(22, 20) /* Destination Chunk Transfer Size */ #define ATC_SRC_WIDTH GENMASK(25, 24) /* Source Single Transfer Size */ #define ATC_DST_WIDTH GENMASK(29, 28) /* Destination Single Transfer Size */ #define ATC_DONE BIT(31) /* Tx Done (only written back in descriptor) */ /* Bitfields in CTRLB */ #define ATC_SIF GENMASK(1, 0) /* Src tx done via AHB-Lite Interface i */ #define ATC_DIF GENMASK(5, 4) /* Dst tx done via AHB-Lite Interface i */ #define AT_DMA_MEM_IF 0x0 /* interface 0 as memory interface */ #define AT_DMA_PER_IF 0x1 /* interface 1 as peripheral interface */ #define ATC_SRC_PIP BIT(8) /* Source Picture-in-Picture enabled */ #define ATC_DST_PIP BIT(12) /* Destination Picture-in-Picture enabled */ #define ATC_SRC_DSCR_DIS BIT(16) /* Src Descriptor fetch disable */ #define ATC_DST_DSCR_DIS BIT(20) /* Dst Descriptor fetch disable */ #define ATC_FC GENMASK(23, 21) /* Choose Flow Controller */ #define ATC_FC_MEM2MEM 0x0 /* Mem-to-Mem (DMA) */ #define ATC_FC_MEM2PER 0x1 /* Mem-to-Periph (DMA) */ #define ATC_FC_PER2MEM 0x2 /* Periph-to-Mem (DMA) */ #define ATC_FC_PER2PER 0x3 /* Periph-to-Periph (DMA) */ #define ATC_FC_PER2MEM_PER 0x4 /* Periph-to-Mem (Peripheral) */ #define ATC_FC_MEM2PER_PER 0x5 /* Mem-to-Periph (Peripheral) */ #define ATC_FC_PER2PER_SRCPER 0x6 /* Periph-to-Periph (Src Peripheral) */ #define ATC_FC_PER2PER_DSTPER 0x7 /* Periph-to-Periph (Dst Peripheral) */ #define ATC_SRC_ADDR_MODE GENMASK(25, 24) #define ATC_SRC_ADDR_MODE_INCR 0x0 /* Incrementing Mode */ #define ATC_SRC_ADDR_MODE_DECR 0x1 /* Decrementing Mode */ #define ATC_SRC_ADDR_MODE_FIXED 0x2 /* Fixed Mode */ #define ATC_DST_ADDR_MODE GENMASK(29, 28) #define ATC_DST_ADDR_MODE_INCR 0x0 /* Incrementing Mode */ #define ATC_DST_ADDR_MODE_DECR 0x1 /* Decrementing Mode */ #define ATC_DST_ADDR_MODE_FIXED 0x2 /* Fixed Mode */ #define ATC_IEN BIT(30) /* BTC interrupt enable (active low) */ #define ATC_AUTO BIT(31) /* Auto multiple buffer tx enable */ /* Bitfields in CFG */ #define ATC_SRC_PER GENMASK(3, 0) /* Channel src rq associated with periph handshaking ifc h */ #define ATC_DST_PER GENMASK(7, 4) /* Channel dst rq associated with periph handshaking ifc h */ #define ATC_SRC_REP BIT(8) /* Source Replay Mod */ #define ATC_SRC_H2SEL BIT(9) /* Source Handshaking Mod */ #define ATC_SRC_PER_MSB GENMASK(11, 10) /* Channel src rq (most significant bits) */ #define ATC_DST_REP BIT(12) /* Destination Replay Mod */ #define ATC_DST_H2SEL BIT(13) /* Destination Handshaking Mod */ #define ATC_DST_PER_MSB GENMASK(15, 14) /* Channel dst rq (most significant bits) */ #define ATC_SOD BIT(16) /* Stop On Done */ #define ATC_LOCK_IF BIT(20) /* Interface Lock */ #define ATC_LOCK_B BIT(21) /* AHB Bus Lock */ #define ATC_LOCK_IF_L BIT(22) /* Master Interface Arbiter Lock */ #define ATC_AHB_PROT GENMASK(26, 24) /* AHB Protection */ #define ATC_FIFOCFG GENMASK(29, 28) /* FIFO Request Configuration */ #define ATC_FIFOCFG_LARGESTBURST 0x0 #define ATC_FIFOCFG_HALFFIFO 0x1 #define ATC_FIFOCFG_ENOUGHSPACE 0x2 /* Bitfields in SPIP */ #define ATC_SPIP_HOLE GENMASK(15, 0) #define ATC_SPIP_BOUNDARY GENMASK(25, 16) /* Bitfields in DPIP */ #define ATC_DPIP_HOLE GENMASK(15, 0) #define ATC_DPIP_BOUNDARY GENMASK(25, 16) #define ATC_PER_MSB GENMASK(5, 4) /* Extract MSBs of a handshaking identifier */ #define ATC_SRC_PER_ID(id) \ ({ typeof(id) _id = (id); \ FIELD_PREP(ATC_SRC_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \ FIELD_PREP(ATC_SRC_PER, _id); }) #define ATC_DST_PER_ID(id) \ ({ typeof(id) _id = (id); \ FIELD_PREP(ATC_DST_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \ FIELD_PREP(ATC_DST_PER, _id); }) /*-- descriptors -----------------------------------------------------*/ /* LLI == Linked List Item; aka DMA buffer descriptor */ struct at_lli { /* values that are not changed by hardware */ u32 saddr; u32 daddr; /* value that may get written back: */ u32 ctrla; /* more values that are not changed by hardware */ u32 ctrlb; u32 dscr; /* chain to next lli */ }; /** * struct atdma_sg - atdma scatter gather entry * @len: length of the current Linked List Item. * @lli: linked list item that is passed to the DMA controller * @lli_phys: physical address of the LLI. */ struct atdma_sg { unsigned int len; struct at_lli *lli; dma_addr_t lli_phys; }; /** * struct at_desc - software descriptor * @vd: pointer to the virtual dma descriptor. * @atchan: pointer to the atmel dma channel. * @total_len: total transaction byte count * @sg_len: number of sg entries. * @sg: array of sgs. */ struct at_desc { struct virt_dma_desc vd; struct at_dma_chan *atchan; size_t total_len; unsigned int sglen; /* Interleaved data */ size_t boundary; size_t dst_hole; size_t src_hole; /* Memset temporary buffer */ bool memset_buffer; dma_addr_t memset_paddr; int *memset_vaddr; struct atdma_sg sg[]; }; /*-- Channels --------------------------------------------------------*/ /** * atc_status - information bits stored in channel status flag * * Manipulated with atomic operations. */ enum atc_status { ATC_IS_PAUSED = 1, ATC_IS_CYCLIC = 24, }; /** * struct at_dma_chan - internal representation of an Atmel HDMAC channel * @vc: virtual dma channel entry. * @atdma: pointer to the driver data. * @ch_regs: memory mapped register base * @mask: channel index in a mask * @per_if: peripheral interface * @mem_if: memory interface * @status: transmit status information from irq/prep* functions * to tasklet (use atomic operations) * @save_cfg: configuration register that is saved on suspend/resume cycle * @save_dscr: for cyclic operations, preserve next descriptor address in * the cyclic list on suspend/resume cycle * @dma_sconfig: configuration for slave transfers, passed via * .device_config * @desc: pointer to the atmel dma descriptor. */ struct at_dma_chan { struct virt_dma_chan vc; struct at_dma *atdma; void __iomem *ch_regs; u8 mask; u8 per_if; u8 mem_if; unsigned long status; u32 save_cfg; u32 save_dscr; struct dma_slave_config dma_sconfig; bool cyclic; struct at_desc *desc; }; #define channel_readl(atchan, name) \ __raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET) #define channel_writel(atchan, name, val) \ __raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET) /* * Fix sconfig's burst size according to at_hdmac. We need to convert them as: * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7. * * This can be done by finding most significant bit set. */ static inline void convert_burst(u32 *maxburst) { if (*maxburst > 1) *maxburst = fls(*maxburst) - 2; else *maxburst = 0; } /* * Fix sconfig's bus width according to at_hdmac. * 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2. */ static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width) { switch (addr_width) { case DMA_SLAVE_BUSWIDTH_2_BYTES: return 1; case DMA_SLAVE_BUSWIDTH_4_BYTES: return 2; default: /* For 1 byte width or fallback */ return 0; } } /*-- Controller ------------------------------------------------------*/ /** * struct at_dma - internal representation of an Atmel HDMA Controller * @dma_device: dmaengine dma_device object members * @atdma_devtype: identifier of DMA controller compatibility * @ch_regs: memory mapped register base * @clk: dma controller clock * @save_imr: interrupt mask register that is saved on suspend/resume cycle * @all_chan_mask: all channels availlable in a mask * @lli_pool: hw lli table * @chan: channels table to store at_dma_chan structures */ struct at_dma { struct dma_device dma_device; void __iomem *regs; struct clk *clk; u32 save_imr; u8 all_chan_mask; struct dma_pool *lli_pool; struct dma_pool *memset_pool; /* AT THE END channels table */ struct at_dma_chan chan[]; }; #define dma_readl(atdma, name) \ __raw_readl((atdma)->regs + AT_DMA_##name) #define dma_writel(atdma, name, val) \ __raw_writel((val), (atdma)->regs + AT_DMA_##name) static inline struct at_desc *to_atdma_desc(struct dma_async_tx_descriptor *t) { return container_of(t, struct at_desc, vd.tx); } static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *chan) { return container_of(chan, struct at_dma_chan, vc.chan); } static inline struct at_dma *to_at_dma(struct dma_device *ddev) { return container_of(ddev, struct at_dma, dma_device); } /*-- Helper functions ------------------------------------------------*/ static struct device *chan2dev(struct dma_chan *chan) { return &chan->dev->device; } #if defined(VERBOSE_DEBUG) static void vdbg_dump_regs(struct at_dma_chan *atchan) { struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); dev_err(chan2dev(&atchan->vc.chan), " channel %d : imr = 0x%x, chsr = 0x%x\n", atchan->vc.chan.chan_id, dma_readl(atdma, EBCIMR), dma_readl(atdma, CHSR)); dev_err(chan2dev(&atchan->vc.chan), " channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n", channel_readl(atchan, SADDR), channel_readl(atchan, DADDR), channel_readl(atchan, CTRLA), channel_readl(atchan, CTRLB), channel_readl(atchan, CFG), channel_readl(atchan, DSCR)); } #else static void vdbg_dump_regs(struct at_dma_chan *atchan) {} #endif static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli) { dev_crit(chan2dev(&atchan->vc.chan), "desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n", &lli->saddr, &lli->daddr, lli->ctrla, lli->ctrlb, &lli->dscr); } static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on) { u32 ebci; /* enable interrupts on buffer transfer completion & error */ ebci = AT_DMA_BTC(chan_id) | AT_DMA_ERR(chan_id); if (on) dma_writel(atdma, EBCIER, ebci); else dma_writel(atdma, EBCIDR, ebci); } static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id) { atc_setup_irq(atdma, chan_id, 1); } static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id) { atc_setup_irq(atdma, chan_id, 0); } /** * atc_chan_is_enabled - test if given channel is enabled * @atchan: channel we want to test status */ static inline int atc_chan_is_enabled(struct at_dma_chan *atchan) { struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); return !!(dma_readl(atdma, CHSR) & atchan->mask); } /** * atc_chan_is_paused - test channel pause/resume status * @atchan: channel we want to test status */ static inline int atc_chan_is_paused(struct at_dma_chan *atchan) { return test_bit(ATC_IS_PAUSED, &atchan->status); } /** * atc_chan_is_cyclic - test if given channel has cyclic property set * @atchan: channel we want to test status */ static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan) { return test_bit(ATC_IS_CYCLIC, &atchan->status); } /** * set_lli_eol - set end-of-link to descriptor so it will end transfer * @desc: descriptor, signle or at the end of a chain, to end chain on * @i: index of the atmel scatter gather entry that is at the end of the chain. */ static void set_lli_eol(struct at_desc *desc, unsigned int i) { u32 ctrlb = desc->sg[i].lli->ctrlb; ctrlb &= ~ATC_IEN; ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS; desc->sg[i].lli->ctrlb = ctrlb; desc->sg[i].lli->dscr = 0; } #define ATC_DEFAULT_CFG FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO) #define ATC_DEFAULT_CTRLB (FIELD_PREP(ATC_SIF, AT_DMA_MEM_IF) | \ FIELD_PREP(ATC_DIF, AT_DMA_MEM_IF)) #define ATC_DMA_BUSWIDTHS\ (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\ BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)) #define ATC_MAX_DSCR_TRIALS 10 /* * Initial number of descriptors to allocate for each channel. This could * be increased during dma usage. */ static unsigned int init_nr_desc_per_channel = 64; module_param(init_nr_desc_per_channel, uint, 0644); MODULE_PARM_DESC(init_nr_desc_per_channel, "initial descriptors per channel (default: 64)"); /** * struct at_dma_platform_data - Controller configuration parameters * @nr_channels: Number of channels supported by hardware (max 8) * @cap_mask: dma_capability flags supported by the platform */ struct at_dma_platform_data { unsigned int nr_channels; dma_cap_mask_t cap_mask; }; /** * struct at_dma_slave - Controller-specific information about a slave * @dma_dev: required DMA master device * @cfg: Platform-specific initializer for the CFG register */ struct at_dma_slave { struct device *dma_dev; u32 cfg; }; static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst, size_t len) { unsigned int width; if (!((src | dst | len) & 3)) width = 2; else if (!((src | dst | len) & 1)) width = 1; else width = 0; return width; } static void atdma_lli_chain(struct at_desc *desc, unsigned int i) { struct atdma_sg *atdma_sg = &desc->sg[i]; if (i) desc->sg[i - 1].lli->dscr = atdma_sg->lli_phys; } /** * atc_dostart - starts the DMA engine for real * @atchan: the channel we want to start */ static void atc_dostart(struct at_dma_chan *atchan) { struct virt_dma_desc *vd = vchan_next_desc(&atchan->vc); struct at_desc *desc; if (!vd) { atchan->desc = NULL; return; } vdbg_dump_regs(atchan); list_del(&vd->node); atchan->desc = desc = to_atdma_desc(&vd->tx); channel_writel(atchan, SADDR, 0); channel_writel(atchan, DADDR, 0); channel_writel(atchan, CTRLA, 0); channel_writel(atchan, CTRLB, 0); channel_writel(atchan, DSCR, desc->sg[0].lli_phys); channel_writel(atchan, SPIP, FIELD_PREP(ATC_SPIP_HOLE, desc->src_hole) | FIELD_PREP(ATC_SPIP_BOUNDARY, desc->boundary)); channel_writel(atchan, DPIP, FIELD_PREP(ATC_DPIP_HOLE, desc->dst_hole) | FIELD_PREP(ATC_DPIP_BOUNDARY, desc->boundary)); /* Don't allow CPU to reorder channel enable. */ wmb(); dma_writel(atchan->atdma, CHER, atchan->mask); vdbg_dump_regs(atchan); } static void atdma_desc_free(struct virt_dma_desc *vd) { struct at_dma *atdma = to_at_dma(vd->tx.chan->device); struct at_desc *desc = to_atdma_desc(&vd->tx); unsigned int i; for (i = 0; i < desc->sglen; i++) { if (desc->sg[i].lli) dma_pool_free(atdma->lli_pool, desc->sg[i].lli, desc->sg[i].lli_phys); } /* If the transfer was a memset, free our temporary buffer */ if (desc->memset_buffer) { dma_pool_free(atdma->memset_pool, desc->memset_vaddr, desc->memset_paddr); desc->memset_buffer = false; } kfree(desc); } /** * atc_calc_bytes_left - calculates the number of bytes left according to the * value read from CTRLA. * * @current_len: the number of bytes left before reading CTRLA * @ctrla: the value of CTRLA */ static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla) { u32 btsize = FIELD_GET(ATC_BTSIZE, ctrla); u32 src_width = FIELD_GET(ATC_SRC_WIDTH, ctrla); /* * According to the datasheet, when reading the Control A Register * (ctrla), the Buffer Transfer Size (btsize) bitfield refers to the * number of transfers completed on the Source Interface. * So btsize is always a number of source width transfers. */ return current_len - (btsize << src_width); } /** * atc_get_llis_residue - Get residue for a hardware linked list transfer * * Calculate the residue by removing the length of the Linked List Item (LLI) * already transferred from the total length. To get the current LLI we can use * the value of the channel's DSCR register and compare it against the DSCR * value of each LLI. * * The CTRLA register provides us with the amount of data already read from the * source for the LLI. So we can compute a more accurate residue by also * removing the number of bytes corresponding to this amount of data. * * However, the DSCR and CTRLA registers cannot be read both atomically. Hence a * race condition may occur: the first read register may refer to one LLI * whereas the second read may refer to a later LLI in the list because of the * DMA transfer progression inbetween the two reads. * * One solution could have been to pause the DMA transfer, read the DSCR and * CTRLA then resume the DMA transfer. Nonetheless, this approach presents some * drawbacks: * - If the DMA transfer is paused, RX overruns or TX underruns are more likey * to occur depending on the system latency. Taking the USART driver as an * example, it uses a cyclic DMA transfer to read data from the Receive * Holding Register (RHR) to avoid RX overruns since the RHR is not protected * by any FIFO on most Atmel SoCs. So pausing the DMA transfer to compute the * residue would break the USART driver design. * - The atc_pause() function masks interrupts but we'd rather avoid to do so * for system latency purpose. * * Then we'd rather use another solution: the DSCR is read a first time, the * CTRLA is read in turn, next the DSCR is read a second time. If the two * consecutive read values of the DSCR are the same then we assume both refers * to the very same LLI as well as the CTRLA value read inbetween does. For * cyclic tranfers, the assumption is that a full loop is "not so fast". If the * two DSCR values are different, we read again the CTRLA then the DSCR till two * consecutive read values from DSCR are equal or till the maximum trials is * reach. This algorithm is very unlikely not to find a stable value for DSCR. * @atchan: pointer to an atmel hdmac channel. * @desc: pointer to the descriptor for which the residue is calculated. * @residue: residue to be set to dma_tx_state. * Returns 0 on success, -errno otherwise. */ static int atc_get_llis_residue(struct at_dma_chan *atchan, struct at_desc *desc, u32 *residue) { u32 len, ctrla, dscr; unsigned int i; len = desc->total_len; dscr = channel_readl(atchan, DSCR); rmb(); /* ensure DSCR is read before CTRLA */ ctrla = channel_readl(atchan, CTRLA); for (i = 0; i < ATC_MAX_DSCR_TRIALS; ++i) { u32 new_dscr; rmb(); /* ensure DSCR is read after CTRLA */ new_dscr = channel_readl(atchan, DSCR); /* * If the DSCR register value has not changed inside the DMA * controller since the previous read, we assume that both the * dscr and ctrla values refers to the very same descriptor. */ if (likely(new_dscr == dscr)) break; /* * DSCR has changed inside the DMA controller, so the previouly * read value of CTRLA may refer to an already processed * descriptor hence could be outdated. We need to update ctrla * to match the current descriptor. */ dscr = new_dscr; rmb(); /* ensure DSCR is read before CTRLA */ ctrla = channel_readl(atchan, CTRLA); } if (unlikely(i == ATC_MAX_DSCR_TRIALS)) return -ETIMEDOUT; /* For the first descriptor we can be more accurate. */ if (desc->sg[0].lli->dscr == dscr) { *residue = atc_calc_bytes_left(len, ctrla); return 0; } len -= desc->sg[0].len; for (i = 1; i < desc->sglen; i++) { if (desc->sg[i].lli && desc->sg[i].lli->dscr == dscr) break; len -= desc->sg[i].len; } /* * For the current LLI in the chain we can calculate the remaining bytes * using the channel's CTRLA register. */ *residue = atc_calc_bytes_left(len, ctrla); return 0; } /** * atc_get_residue - get the number of bytes residue for a cookie. * The residue is passed by address and updated on success. * @chan: DMA channel * @cookie: transaction identifier to check status of * @residue: residue to be updated. * Return 0 on success, -errono otherwise. */ static int atc_get_residue(struct dma_chan *chan, dma_cookie_t cookie, u32 *residue) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct virt_dma_desc *vd; struct at_desc *desc = NULL; u32 len, ctrla; vd = vchan_find_desc(&atchan->vc, cookie); if (vd) desc = to_atdma_desc(&vd->tx); else if (atchan->desc && atchan->desc->vd.tx.cookie == cookie) desc = atchan->desc; if (!desc) return -EINVAL; if (desc->sg[0].lli->dscr) /* hardware linked list transfer */ return atc_get_llis_residue(atchan, desc, residue); /* single transfer */ len = desc->total_len; ctrla = channel_readl(atchan, CTRLA); *residue = atc_calc_bytes_left(len, ctrla); return 0; } /** * atc_handle_error - handle errors reported by DMA controller * @atchan: channel where error occurs. * @i: channel index */ static void atc_handle_error(struct at_dma_chan *atchan, unsigned int i) { struct at_desc *desc = atchan->desc; /* Disable channel on AHB error */ dma_writel(atchan->atdma, CHDR, AT_DMA_RES(i) | atchan->mask); /* * KERN_CRITICAL may seem harsh, but since this only happens * when someone submits a bad physical address in a * descriptor, we should consider ourselves lucky that the * controller flagged an error instead of scribbling over * random memory locations. */ dev_crit(chan2dev(&atchan->vc.chan), "Bad descriptor submitted for DMA!\n"); dev_crit(chan2dev(&atchan->vc.chan), "cookie: %d\n", desc->vd.tx.cookie); for (i = 0; i < desc->sglen; i++) atc_dump_lli(atchan, desc->sg[i].lli); } static void atdma_handle_chan_done(struct at_dma_chan *atchan, u32 pending, unsigned int i) { struct at_desc *desc; spin_lock(&atchan->vc.lock); desc = atchan->desc; if (desc) { if (pending & AT_DMA_ERR(i)) { atc_handle_error(atchan, i); /* Pretend the descriptor completed successfully */ } if (atc_chan_is_cyclic(atchan)) { vchan_cyclic_callback(&desc->vd); } else { vchan_cookie_complete(&desc->vd); atchan->desc = NULL; if (!(atc_chan_is_enabled(atchan))) atc_dostart(atchan); } } spin_unlock(&atchan->vc.lock); } static irqreturn_t at_dma_interrupt(int irq, void *dev_id) { struct at_dma *atdma = dev_id; struct at_dma_chan *atchan; int i; u32 status, pending, imr; int ret = IRQ_NONE; do { imr = dma_readl(atdma, EBCIMR); status = dma_readl(atdma, EBCISR); pending = status & imr; if (!pending) break; dev_vdbg(atdma->dma_device.dev, "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n", status, imr, pending); for (i = 0; i < atdma->dma_device.chancnt; i++) { atchan = &atdma->chan[i]; if (!(pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i)))) continue; atdma_handle_chan_done(atchan, pending, i); ret = IRQ_HANDLED; } } while (pending); return ret; } /*-- DMA Engine API --------------------------------------------------*/ /** * atc_prep_dma_interleaved - prepare memory to memory interleaved operation * @chan: the channel to prepare operation on * @xt: Interleaved transfer template * @flags: tx descriptor status flags */ static struct dma_async_tx_descriptor * atc_prep_dma_interleaved(struct dma_chan *chan, struct dma_interleaved_template *xt, unsigned long flags) { struct at_dma *atdma = to_at_dma(chan->device); struct at_dma_chan *atchan = to_at_dma_chan(chan); struct data_chunk *first; struct atdma_sg *atdma_sg; struct at_desc *desc; struct at_lli *lli; size_t xfer_count; unsigned int dwidth; u32 ctrla; u32 ctrlb; size_t len = 0; int i; if (unlikely(!xt || xt->numf != 1 || !xt->frame_size)) return NULL; first = xt->sgl; dev_info(chan2dev(chan), "%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n", __func__, &xt->src_start, &xt->dst_start, xt->numf, xt->frame_size, flags); /* * The controller can only "skip" X bytes every Y bytes, so we * need to make sure we are given a template that fit that * description, ie a template with chunks that always have the * same size, with the same ICGs. */ for (i = 0; i < xt->frame_size; i++) { struct data_chunk *chunk = xt->sgl + i; if ((chunk->size != xt->sgl->size) || (dmaengine_get_dst_icg(xt, chunk) != dmaengine_get_dst_icg(xt, first)) || (dmaengine_get_src_icg(xt, chunk) != dmaengine_get_src_icg(xt, first))) { dev_err(chan2dev(chan), "%s: the controller can transfer only identical chunks\n", __func__); return NULL; } len += chunk->size; } dwidth = atc_get_xfer_width(xt->src_start, xt->dst_start, len); xfer_count = len >> dwidth; if (xfer_count > ATC_BTSIZE_MAX) { dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__); return NULL; } ctrla = FIELD_PREP(ATC_SRC_WIDTH, dwidth) | FIELD_PREP(ATC_DST_WIDTH, dwidth); ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | ATC_SRC_PIP | ATC_DST_PIP | FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC); if (!desc) return NULL; desc->sglen = 1; atdma_sg = desc->sg; atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, &atdma_sg->lli_phys); if (!atdma_sg->lli) { kfree(desc); return NULL; } lli = atdma_sg->lli; lli->saddr = xt->src_start; lli->daddr = xt->dst_start; lli->ctrla = ctrla | xfer_count; lli->ctrlb = ctrlb; desc->boundary = first->size >> dwidth; desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1; desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1; atdma_sg->len = len; desc->total_len = len; set_lli_eol(desc, 0); return vchan_tx_prep(&atchan->vc, &desc->vd, flags); } /** * atc_prep_dma_memcpy - prepare a memcpy operation * @chan: the channel to prepare operation on * @dest: operation virtual destination address * @src: operation virtual source address * @len: operation length * @flags: tx descriptor status flags */ static struct dma_async_tx_descriptor * atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len, unsigned long flags) { struct at_dma *atdma = to_at_dma(chan->device); struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_desc *desc = NULL; size_t xfer_count; size_t offset; size_t sg_len; unsigned int src_width; unsigned int dst_width; unsigned int i; u32 ctrla; u32 ctrlb; dev_dbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n", &dest, &src, len, flags); if (unlikely(!len)) { dev_err(chan2dev(chan), "prep_dma_memcpy: length is zero!\n"); return NULL; } sg_len = DIV_ROUND_UP(len, ATC_BTSIZE_MAX); desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); if (!desc) return NULL; desc->sglen = sg_len; ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); /* * We can be a lot more clever here, but this should take care * of the most common optimization. */ src_width = dst_width = atc_get_xfer_width(src, dest, len); ctrla = FIELD_PREP(ATC_SRC_WIDTH, src_width) | FIELD_PREP(ATC_DST_WIDTH, dst_width); for (offset = 0, i = 0; offset < len; offset += xfer_count << src_width, i++) { struct atdma_sg *atdma_sg = &desc->sg[i]; struct at_lli *lli; atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, &atdma_sg->lli_phys); if (!atdma_sg->lli) goto err_desc_get; lli = atdma_sg->lli; xfer_count = min_t(size_t, (len - offset) >> src_width, ATC_BTSIZE_MAX); lli->saddr = src + offset; lli->daddr = dest + offset; lli->ctrla = ctrla | xfer_count; lli->ctrlb = ctrlb; desc->sg[i].len = xfer_count << src_width; atdma_lli_chain(desc, i); } desc->total_len = len; /* set end-of-link to the last link descriptor of list*/ set_lli_eol(desc, i - 1); return vchan_tx_prep(&atchan->vc, &desc->vd, flags); err_desc_get: atdma_desc_free(&desc->vd); return NULL; } static int atdma_create_memset_lli(struct dma_chan *chan, struct atdma_sg *atdma_sg, dma_addr_t psrc, dma_addr_t pdst, size_t len) { struct at_dma *atdma = to_at_dma(chan->device); struct at_lli *lli; size_t xfer_count; u32 ctrla = FIELD_PREP(ATC_SRC_WIDTH, 2) | FIELD_PREP(ATC_DST_WIDTH, 2); u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) | FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); xfer_count = len >> 2; if (xfer_count > ATC_BTSIZE_MAX) { dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__); return -EINVAL; } atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, &atdma_sg->lli_phys); if (!atdma_sg->lli) return -ENOMEM; lli = atdma_sg->lli; lli->saddr = psrc; lli->daddr = pdst; lli->ctrla = ctrla | xfer_count; lli->ctrlb = ctrlb; atdma_sg->len = len; return 0; } /** * atc_prep_dma_memset - prepare a memcpy operation * @chan: the channel to prepare operation on * @dest: operation virtual destination address * @value: value to set memory buffer to * @len: operation length * @flags: tx descriptor status flags */ static struct dma_async_tx_descriptor * atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value, size_t len, unsigned long flags) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma *atdma = to_at_dma(chan->device); struct at_desc *desc; void __iomem *vaddr; dma_addr_t paddr; char fill_pattern; int ret; dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__, &dest, value, len, flags); if (unlikely(!len)) { dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__); return NULL; } if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n", __func__); return NULL; } vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr); if (!vaddr) { dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", __func__); return NULL; } /* Only the first byte of value is to be used according to dmaengine */ fill_pattern = (char)value; *(u32*)vaddr = (fill_pattern << 24) | (fill_pattern << 16) | (fill_pattern << 8) | fill_pattern; desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC); if (!desc) goto err_free_buffer; desc->sglen = 1; ret = atdma_create_memset_lli(chan, desc->sg, paddr, dest, len); if (ret) goto err_free_desc; desc->memset_paddr = paddr; desc->memset_vaddr = vaddr; desc->memset_buffer = true; desc->total_len = len; /* set end-of-link on the descriptor */ set_lli_eol(desc, 0); return vchan_tx_prep(&atchan->vc, &desc->vd, flags); err_free_desc: kfree(desc); err_free_buffer: dma_pool_free(atdma->memset_pool, vaddr, paddr); return NULL; } static struct dma_async_tx_descriptor * atc_prep_dma_memset_sg(struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, int value, unsigned long flags) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma *atdma = to_at_dma(chan->device); struct at_desc *desc; struct scatterlist *sg; void __iomem *vaddr; dma_addr_t paddr; size_t total_len = 0; int i; int ret; dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__, value, sg_len, flags); if (unlikely(!sgl || !sg_len)) { dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n", __func__); return NULL; } vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr); if (!vaddr) { dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", __func__); return NULL; } *(u32*)vaddr = value; desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); if (!desc) goto err_free_dma_buf; desc->sglen = sg_len; for_each_sg(sgl, sg, sg_len, i) { dma_addr_t dest = sg_dma_address(sg); size_t len = sg_dma_len(sg); dev_vdbg(chan2dev(chan), "%s: d%pad, l0x%zx\n", __func__, &dest, len); if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { dev_err(chan2dev(chan), "%s: buffer is not aligned\n", __func__); goto err_free_desc; } ret = atdma_create_memset_lli(chan, &desc->sg[i], paddr, dest, len); if (ret) goto err_free_desc; atdma_lli_chain(desc, i); total_len += len; } desc->memset_paddr = paddr; desc->memset_vaddr = vaddr; desc->memset_buffer = true; desc->total_len = total_len; /* set end-of-link on the descriptor */ set_lli_eol(desc, i - 1); return vchan_tx_prep(&atchan->vc, &desc->vd, flags); err_free_desc: atdma_desc_free(&desc->vd); err_free_dma_buf: dma_pool_free(atdma->memset_pool, vaddr, paddr); return NULL; } /** * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction * @chan: DMA channel * @sgl: scatterlist to transfer to/from * @sg_len: number of entries in @scatterlist * @direction: DMA direction * @flags: tx descriptor status flags * @context: transaction context (ignored) */ static struct dma_async_tx_descriptor * atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, unsigned long flags, void *context) { struct at_dma *atdma = to_at_dma(chan->device); struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma_slave *atslave = chan->private; struct dma_slave_config *sconfig = &atchan->dma_sconfig; struct at_desc *desc; u32 ctrla; u32 ctrlb; dma_addr_t reg; unsigned int reg_width; unsigned int mem_width; unsigned int i; struct scatterlist *sg; size_t total_len = 0; dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n", sg_len, direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", flags); if (unlikely(!atslave || !sg_len)) { dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n"); return NULL; } desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); if (!desc) return NULL; desc->sglen = sg_len; ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) | FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst); ctrlb = ATC_IEN; switch (direction) { case DMA_MEM_TO_DEV: reg_width = convert_buswidth(sconfig->dst_addr_width); ctrla |= FIELD_PREP(ATC_DST_WIDTH, reg_width); ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_FIXED) | FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) | FIELD_PREP(ATC_SIF, atchan->mem_if) | FIELD_PREP(ATC_DIF, atchan->per_if); reg = sconfig->dst_addr; for_each_sg(sgl, sg, sg_len, i) { struct atdma_sg *atdma_sg = &desc->sg[i]; struct at_lli *lli; u32 len; u32 mem; atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, &atdma_sg->lli_phys); if (!atdma_sg->lli) goto err_desc_get; lli = atdma_sg->lli; mem = sg_dma_address(sg); len = sg_dma_len(sg); if (unlikely(!len)) { dev_dbg(chan2dev(chan), "prep_slave_sg: sg(%d) data length is zero\n", i); goto err; } mem_width = 2; if (unlikely(mem & 3 || len & 3)) mem_width = 0; lli->saddr = mem; lli->daddr = reg; lli->ctrla = ctrla | FIELD_PREP(ATC_SRC_WIDTH, mem_width) | len >> mem_width; lli->ctrlb = ctrlb; atdma_sg->len = len; total_len += len; desc->sg[i].len = len; atdma_lli_chain(desc, i); } break; case DMA_DEV_TO_MEM: reg_width = convert_buswidth(sconfig->src_addr_width); ctrla |= FIELD_PREP(ATC_SRC_WIDTH, reg_width); ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) | FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) | FIELD_PREP(ATC_SIF, atchan->per_if) | FIELD_PREP(ATC_DIF, atchan->mem_if); reg = sconfig->src_addr; for_each_sg(sgl, sg, sg_len, i) { struct atdma_sg *atdma_sg = &desc->sg[i]; struct at_lli *lli; u32 len; u32 mem; atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, &atdma_sg->lli_phys); if (!atdma_sg->lli) goto err_desc_get; lli = atdma_sg->lli; mem = sg_dma_address(sg); len = sg_dma_len(sg); if (unlikely(!len)) { dev_dbg(chan2dev(chan), "prep_slave_sg: sg(%d) data length is zero\n", i); goto err; } mem_width = 2; if (unlikely(mem & 3 || len & 3)) mem_width = 0; lli->saddr = reg; lli->daddr = mem; lli->ctrla = ctrla | FIELD_PREP(ATC_DST_WIDTH, mem_width) | len >> reg_width; lli->ctrlb = ctrlb; desc->sg[i].len = len; total_len += len; atdma_lli_chain(desc, i); } break; default: return NULL; } /* set end-of-link to the last link descriptor of list*/ set_lli_eol(desc, i - 1); desc->total_len = total_len; return vchan_tx_prep(&atchan->vc, &desc->vd, flags); err_desc_get: dev_err(chan2dev(chan), "not enough descriptors available\n"); err: atdma_desc_free(&desc->vd); return NULL; } /* * atc_dma_cyclic_check_values * Check for too big/unaligned periods and unaligned DMA buffer */ static int atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr, size_t period_len) { if (period_len > (ATC_BTSIZE_MAX << reg_width)) goto err_out; if (unlikely(period_len & ((1 << reg_width) - 1))) goto err_out; if (unlikely(buf_addr & ((1 << reg_width) - 1))) goto err_out; return 0; err_out: return -EINVAL; } /* * atc_dma_cyclic_fill_desc - Fill one period descriptor */ static int atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc, unsigned int i, dma_addr_t buf_addr, unsigned int reg_width, size_t period_len, enum dma_transfer_direction direction) { struct at_dma *atdma = to_at_dma(chan->device); struct at_dma_chan *atchan = to_at_dma_chan(chan); struct dma_slave_config *sconfig = &atchan->dma_sconfig; struct atdma_sg *atdma_sg = &desc->sg[i]; struct at_lli *lli; atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_ATOMIC, &atdma_sg->lli_phys); if (!atdma_sg->lli) return -ENOMEM; lli = atdma_sg->lli; switch (direction) { case DMA_MEM_TO_DEV: lli->saddr = buf_addr + (period_len * i); lli->daddr = sconfig->dst_addr; lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_FIXED) | FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) | FIELD_PREP(ATC_SIF, atchan->mem_if) | FIELD_PREP(ATC_DIF, atchan->per_if); break; case DMA_DEV_TO_MEM: lli->saddr = sconfig->src_addr; lli->daddr = buf_addr + (period_len * i); lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) | FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) | FIELD_PREP(ATC_SIF, atchan->per_if) | FIELD_PREP(ATC_DIF, atchan->mem_if); break; default: return -EINVAL; } lli->ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) | FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) | FIELD_PREP(ATC_DST_WIDTH, reg_width) | FIELD_PREP(ATC_SRC_WIDTH, reg_width) | period_len >> reg_width; desc->sg[i].len = period_len; return 0; } /** * atc_prep_dma_cyclic - prepare the cyclic DMA transfer * @chan: the DMA channel to prepare * @buf_addr: physical DMA address where the buffer starts * @buf_len: total number of bytes for the entire buffer * @period_len: number of bytes for each period * @direction: transfer direction, to or from device * @flags: tx descriptor status flags */ static struct dma_async_tx_descriptor * atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, size_t period_len, enum dma_transfer_direction direction, unsigned long flags) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma_slave *atslave = chan->private; struct dma_slave_config *sconfig = &atchan->dma_sconfig; struct at_desc *desc; unsigned long was_cyclic; unsigned int reg_width; unsigned int periods = buf_len / period_len; unsigned int i; dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@%pad - %d (%d/%d)\n", direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", &buf_addr, periods, buf_len, period_len); if (unlikely(!atslave || !buf_len || !period_len)) { dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n"); return NULL; } was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status); if (was_cyclic) { dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n"); return NULL; } if (unlikely(!is_slave_direction(direction))) goto err_out; if (direction == DMA_MEM_TO_DEV) reg_width = convert_buswidth(sconfig->dst_addr_width); else reg_width = convert_buswidth(sconfig->src_addr_width); /* Check for too big/unaligned periods and unaligned DMA buffer */ if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len)) goto err_out; desc = kzalloc(struct_size(desc, sg, periods), GFP_ATOMIC); if (!desc) goto err_out; desc->sglen = periods; /* build cyclic linked list */ for (i = 0; i < periods; i++) { if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr, reg_width, period_len, direction)) goto err_fill_desc; atdma_lli_chain(desc, i); } desc->total_len = buf_len; /* lets make a cyclic list */ desc->sg[i - 1].lli->dscr = desc->sg[0].lli_phys; return vchan_tx_prep(&atchan->vc, &desc->vd, flags); err_fill_desc: atdma_desc_free(&desc->vd); err_out: clear_bit(ATC_IS_CYCLIC, &atchan->status); return NULL; } static int atc_config(struct dma_chan *chan, struct dma_slave_config *sconfig) { struct at_dma_chan *atchan = to_at_dma_chan(chan); dev_vdbg(chan2dev(chan), "%s\n", __func__); /* Check if it is chan is configured for slave transfers */ if (!chan->private) return -EINVAL; memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig)); convert_burst(&atchan->dma_sconfig.src_maxburst); convert_burst(&atchan->dma_sconfig.dst_maxburst); return 0; } static int atc_pause(struct dma_chan *chan) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma *atdma = to_at_dma(chan->device); int chan_id = atchan->vc.chan.chan_id; unsigned long flags; dev_vdbg(chan2dev(chan), "%s\n", __func__); spin_lock_irqsave(&atchan->vc.lock, flags); dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id)); set_bit(ATC_IS_PAUSED, &atchan->status); spin_unlock_irqrestore(&atchan->vc.lock, flags); return 0; } static int atc_resume(struct dma_chan *chan) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma *atdma = to_at_dma(chan->device); int chan_id = atchan->vc.chan.chan_id; unsigned long flags; dev_vdbg(chan2dev(chan), "%s\n", __func__); if (!atc_chan_is_paused(atchan)) return 0; spin_lock_irqsave(&atchan->vc.lock, flags); dma_writel(atdma, CHDR, AT_DMA_RES(chan_id)); clear_bit(ATC_IS_PAUSED, &atchan->status); spin_unlock_irqrestore(&atchan->vc.lock, flags); return 0; } static int atc_terminate_all(struct dma_chan *chan) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma *atdma = to_at_dma(chan->device); int chan_id = atchan->vc.chan.chan_id; unsigned long flags; LIST_HEAD(list); dev_vdbg(chan2dev(chan), "%s\n", __func__); /* * This is only called when something went wrong elsewhere, so * we don't really care about the data. Just disable the * channel. We still have to poll the channel enable bit due * to AHB/HSB limitations. */ spin_lock_irqsave(&atchan->vc.lock, flags); /* disabling channel: must also remove suspend state */ dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask); /* confirm that this channel is disabled */ while (dma_readl(atdma, CHSR) & atchan->mask) cpu_relax(); if (atchan->desc) { vchan_terminate_vdesc(&atchan->desc->vd); atchan->desc = NULL; } vchan_get_all_descriptors(&atchan->vc, &list); clear_bit(ATC_IS_PAUSED, &atchan->status); /* if channel dedicated to cyclic operations, free it */ clear_bit(ATC_IS_CYCLIC, &atchan->status); spin_unlock_irqrestore(&atchan->vc.lock, flags); vchan_dma_desc_free_list(&atchan->vc, &list); return 0; } /** * atc_tx_status - poll for transaction completion * @chan: DMA channel * @cookie: transaction identifier to check status of * @txstate: if not %NULL updated with transaction state * * If @txstate is passed in, upon return it reflect the driver * internal state and can be used with dma_async_is_complete() to check * the status of multiple cookies without re-checking hardware state. */ static enum dma_status atc_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct at_dma_chan *atchan = to_at_dma_chan(chan); unsigned long flags; enum dma_status dma_status; u32 residue; int ret; dma_status = dma_cookie_status(chan, cookie, txstate); if (dma_status == DMA_COMPLETE || !txstate) return dma_status; spin_lock_irqsave(&atchan->vc.lock, flags); /* Get number of bytes left in the active transactions */ ret = atc_get_residue(chan, cookie, &residue); spin_unlock_irqrestore(&atchan->vc.lock, flags); if (unlikely(ret < 0)) { dev_vdbg(chan2dev(chan), "get residual bytes error\n"); return DMA_ERROR; } else { dma_set_residue(txstate, residue); } dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %u\n", dma_status, cookie, residue); return dma_status; } static void atc_issue_pending(struct dma_chan *chan) { struct at_dma_chan *atchan = to_at_dma_chan(chan); unsigned long flags; spin_lock_irqsave(&atchan->vc.lock, flags); if (vchan_issue_pending(&atchan->vc) && !atchan->desc) { if (!(atc_chan_is_enabled(atchan))) atc_dostart(atchan); } spin_unlock_irqrestore(&atchan->vc.lock, flags); } /** * atc_alloc_chan_resources - allocate resources for DMA channel * @chan: allocate descriptor resources for this channel * * return - the number of allocated descriptors */ static int atc_alloc_chan_resources(struct dma_chan *chan) { struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma *atdma = to_at_dma(chan->device); struct at_dma_slave *atslave; u32 cfg; dev_vdbg(chan2dev(chan), "alloc_chan_resources\n"); /* ASSERT: channel is idle */ if (atc_chan_is_enabled(atchan)) { dev_dbg(chan2dev(chan), "DMA channel not idle ?\n"); return -EIO; } cfg = ATC_DEFAULT_CFG; atslave = chan->private; if (atslave) { /* * We need controller-specific data to set up slave * transfers. */ BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_device.dev); /* if cfg configuration specified take it instead of default */ if (atslave->cfg) cfg = atslave->cfg; } /* channel parameters */ channel_writel(atchan, CFG, cfg); return 0; } /** * atc_free_chan_resources - free all channel resources * @chan: DMA channel */ static void atc_free_chan_resources(struct dma_chan *chan) { struct at_dma_chan *atchan = to_at_dma_chan(chan); BUG_ON(atc_chan_is_enabled(atchan)); vchan_free_chan_resources(to_virt_chan(chan)); atchan->status = 0; /* * Free atslave allocated in at_dma_xlate() */ kfree(chan->private); chan->private = NULL; dev_vdbg(chan2dev(chan), "free_chan_resources: done\n"); } #ifdef CONFIG_OF static bool at_dma_filter(struct dma_chan *chan, void *slave) { struct at_dma_slave *atslave = slave; if (atslave->dma_dev == chan->device->dev) { chan->private = atslave; return true; } else { return false; } } static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, struct of_dma *of_dma) { struct dma_chan *chan; struct at_dma_chan *atchan; struct at_dma_slave *atslave; dma_cap_mask_t mask; unsigned int per_id; struct platform_device *dmac_pdev; if (dma_spec->args_count != 2) return NULL; dmac_pdev = of_find_device_by_node(dma_spec->np); if (!dmac_pdev) return NULL; dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); atslave = kmalloc(sizeof(*atslave), GFP_KERNEL); if (!atslave) { put_device(&dmac_pdev->dev); return NULL; } atslave->cfg = ATC_DST_H2SEL | ATC_SRC_H2SEL; /* * We can fill both SRC_PER and DST_PER, one of these fields will be * ignored depending on DMA transfer direction. */ per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK; atslave->cfg |= ATC_DST_PER_ID(per_id) | ATC_SRC_PER_ID(per_id); /* * We have to translate the value we get from the device tree since * the half FIFO configuration value had to be 0 to keep backward * compatibility. */ switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) { case AT91_DMA_CFG_FIFOCFG_ALAP: atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_LARGESTBURST); break; case AT91_DMA_CFG_FIFOCFG_ASAP: atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_ENOUGHSPACE); break; case AT91_DMA_CFG_FIFOCFG_HALF: default: atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO); } atslave->dma_dev = &dmac_pdev->dev; chan = dma_request_channel(mask, at_dma_filter, atslave); if (!chan) { put_device(&dmac_pdev->dev); kfree(atslave); return NULL; } atchan = to_at_dma_chan(chan); atchan->per_if = dma_spec->args[0] & 0xff; atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff; return chan; } #else static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, struct of_dma *of_dma) { return NULL; } #endif /*-- Module Management -----------------------------------------------*/ /* cap_mask is a multi-u32 bitfield, fill it with proper C code. */ static struct at_dma_platform_data at91sam9rl_config = { .nr_channels = 2, }; static struct at_dma_platform_data at91sam9g45_config = { .nr_channels = 8, }; #if defined(CONFIG_OF) static const struct of_device_id atmel_dma_dt_ids[] = { { .compatible = "atmel,at91sam9rl-dma", .data = &at91sam9rl_config, }, { .compatible = "atmel,at91sam9g45-dma", .data = &at91sam9g45_config, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids); #endif static const struct platform_device_id atdma_devtypes[] = { { .name = "at91sam9rl_dma", .driver_data = (unsigned long) &at91sam9rl_config, }, { .name = "at91sam9g45_dma", .driver_data = (unsigned long) &at91sam9g45_config, }, { /* sentinel */ } }; static inline const struct at_dma_platform_data * __init at_dma_get_driver_data( struct platform_device *pdev) { if (pdev->dev.of_node) { const struct of_device_id *match; match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node); if (match == NULL) return NULL; return match->data; } return (struct at_dma_platform_data *) platform_get_device_id(pdev)->driver_data; } /** * at_dma_off - disable DMA controller * @atdma: the Atmel HDAMC device */ static void at_dma_off(struct at_dma *atdma) { dma_writel(atdma, EN, 0); /* disable all interrupts */ dma_writel(atdma, EBCIDR, -1L); /* confirm that all channels are disabled */ while (dma_readl(atdma, CHSR) & atdma->all_chan_mask) cpu_relax(); } static int __init at_dma_probe(struct platform_device *pdev) { struct at_dma *atdma; int irq; int err; int i; const struct at_dma_platform_data *plat_dat; /* setup platform data for each SoC */ dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask); dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask); dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask); dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask); dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask); dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask); dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask); /* get DMA parameters from controller type */ plat_dat = at_dma_get_driver_data(pdev); if (!plat_dat) return -ENODEV; atdma = devm_kzalloc(&pdev->dev, struct_size(atdma, chan, plat_dat->nr_channels), GFP_KERNEL); if (!atdma) return -ENOMEM; atdma->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(atdma->regs)) return PTR_ERR(atdma->regs); irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; /* discover transaction capabilities */ atdma->dma_device.cap_mask = plat_dat->cap_mask; atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1; atdma->clk = devm_clk_get(&pdev->dev, "dma_clk"); if (IS_ERR(atdma->clk)) return PTR_ERR(atdma->clk); err = clk_prepare_enable(atdma->clk); if (err) return err; /* force dma off, just in case */ at_dma_off(atdma); err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma); if (err) goto err_irq; platform_set_drvdata(pdev, atdma); /* create a pool of consistent memory blocks for hardware descriptors */ atdma->lli_pool = dma_pool_create("at_hdmac_lli_pool", &pdev->dev, sizeof(struct at_lli), 4 /* word alignment */, 0); if (!atdma->lli_pool) { dev_err(&pdev->dev, "Unable to allocate DMA LLI descriptor pool\n"); err = -ENOMEM; goto err_desc_pool_create; } /* create a pool of consistent memory blocks for memset blocks */ atdma->memset_pool = dma_pool_create("at_hdmac_memset_pool", &pdev->dev, sizeof(int), 4, 0); if (!atdma->memset_pool) { dev_err(&pdev->dev, "No memory for memset dma pool\n"); err = -ENOMEM; goto err_memset_pool_create; } /* clear any pending interrupt */ while (dma_readl(atdma, EBCISR)) cpu_relax(); /* initialize channels related values */ INIT_LIST_HEAD(&atdma->dma_device.channels); for (i = 0; i < plat_dat->nr_channels; i++) { struct at_dma_chan *atchan = &atdma->chan[i]; atchan->mem_if = AT_DMA_MEM_IF; atchan->per_if = AT_DMA_PER_IF; atchan->ch_regs = atdma->regs + ch_regs(i); atchan->mask = 1 << i; atchan->atdma = atdma; atchan->vc.desc_free = atdma_desc_free; vchan_init(&atchan->vc, &atdma->dma_device); atc_enable_chan_irq(atdma, i); } /* set base routines */ atdma->dma_device.device_alloc_chan_resources = atc_alloc_chan_resources; atdma->dma_device.device_free_chan_resources = atc_free_chan_resources; atdma->dma_device.device_tx_status = atc_tx_status; atdma->dma_device.device_issue_pending = atc_issue_pending; atdma->dma_device.dev = &pdev->dev; /* set prep routines based on capability */ if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_device.cap_mask)) atdma->dma_device.device_prep_interleaved_dma = atc_prep_dma_interleaved; if (dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask)) atdma->dma_device.device_prep_dma_memcpy = atc_prep_dma_memcpy; if (dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask)) { atdma->dma_device.device_prep_dma_memset = atc_prep_dma_memset; atdma->dma_device.device_prep_dma_memset_sg = atc_prep_dma_memset_sg; atdma->dma_device.fill_align = DMAENGINE_ALIGN_4_BYTES; } if (dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask)) { atdma->dma_device.device_prep_slave_sg = atc_prep_slave_sg; /* controller can do slave DMA: can trigger cyclic transfers */ dma_cap_set(DMA_CYCLIC, atdma->dma_device.cap_mask); atdma->dma_device.device_prep_dma_cyclic = atc_prep_dma_cyclic; atdma->dma_device.device_config = atc_config; atdma->dma_device.device_pause = atc_pause; atdma->dma_device.device_resume = atc_resume; atdma->dma_device.device_terminate_all = atc_terminate_all; atdma->dma_device.src_addr_widths = ATC_DMA_BUSWIDTHS; atdma->dma_device.dst_addr_widths = ATC_DMA_BUSWIDTHS; atdma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); atdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; } dma_writel(atdma, EN, AT_DMA_ENABLE); dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n", dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask) ? "cpy " : "", dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask) ? "set " : "", dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask) ? "slave " : "", plat_dat->nr_channels); err = dma_async_device_register(&atdma->dma_device); if (err) { dev_err(&pdev->dev, "Unable to register: %d.\n", err); goto err_dma_async_device_register; } /* * Do not return an error if the dmac node is not present in order to * not break the existing way of requesting channel with * dma_request_channel(). */ if (pdev->dev.of_node) { err = of_dma_controller_register(pdev->dev.of_node, at_dma_xlate, atdma); if (err) { dev_err(&pdev->dev, "could not register of_dma_controller\n"); goto err_of_dma_controller_register; } } return 0; err_of_dma_controller_register: dma_async_device_unregister(&atdma->dma_device); err_dma_async_device_register: dma_pool_destroy(atdma->memset_pool); err_memset_pool_create: dma_pool_destroy(atdma->lli_pool); err_desc_pool_create: free_irq(platform_get_irq(pdev, 0), atdma); err_irq: clk_disable_unprepare(atdma->clk); return err; } static int at_dma_remove(struct platform_device *pdev) { struct at_dma *atdma = platform_get_drvdata(pdev); struct dma_chan *chan, *_chan; at_dma_off(atdma); if (pdev->dev.of_node) of_dma_controller_free(pdev->dev.of_node); dma_async_device_unregister(&atdma->dma_device); dma_pool_destroy(atdma->memset_pool); dma_pool_destroy(atdma->lli_pool); free_irq(platform_get_irq(pdev, 0), atdma); list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, device_node) { /* Disable interrupts */ atc_disable_chan_irq(atdma, chan->chan_id); list_del(&chan->device_node); } clk_disable_unprepare(atdma->clk); return 0; } static void at_dma_shutdown(struct platform_device *pdev) { struct at_dma *atdma = platform_get_drvdata(pdev); at_dma_off(platform_get_drvdata(pdev)); clk_disable_unprepare(atdma->clk); } static int at_dma_prepare(struct device *dev) { struct at_dma *atdma = dev_get_drvdata(dev); struct dma_chan *chan, *_chan; list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, device_node) { struct at_dma_chan *atchan = to_at_dma_chan(chan); /* wait for transaction completion (except in cyclic case) */ if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan)) return -EAGAIN; } return 0; } static void atc_suspend_cyclic(struct at_dma_chan *atchan) { struct dma_chan *chan = &atchan->vc.chan; /* Channel should be paused by user * do it anyway even if it is not done already */ if (!atc_chan_is_paused(atchan)) { dev_warn(chan2dev(chan), "cyclic channel not paused, should be done by channel user\n"); atc_pause(chan); } /* now preserve additional data for cyclic operations */ /* next descriptor address in the cyclic list */ atchan->save_dscr = channel_readl(atchan, DSCR); vdbg_dump_regs(atchan); } static int at_dma_suspend_noirq(struct device *dev) { struct at_dma *atdma = dev_get_drvdata(dev); struct dma_chan *chan, *_chan; /* preserve data */ list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, device_node) { struct at_dma_chan *atchan = to_at_dma_chan(chan); if (atc_chan_is_cyclic(atchan)) atc_suspend_cyclic(atchan); atchan->save_cfg = channel_readl(atchan, CFG); } atdma->save_imr = dma_readl(atdma, EBCIMR); /* disable DMA controller */ at_dma_off(atdma); clk_disable_unprepare(atdma->clk); return 0; } static void atc_resume_cyclic(struct at_dma_chan *atchan) { struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); /* restore channel status for cyclic descriptors list: * next descriptor in the cyclic list at the time of suspend */ channel_writel(atchan, SADDR, 0); channel_writel(atchan, DADDR, 0); channel_writel(atchan, CTRLA, 0); channel_writel(atchan, CTRLB, 0); channel_writel(atchan, DSCR, atchan->save_dscr); dma_writel(atdma, CHER, atchan->mask); /* channel pause status should be removed by channel user * We cannot take the initiative to do it here */ vdbg_dump_regs(atchan); } static int at_dma_resume_noirq(struct device *dev) { struct at_dma *atdma = dev_get_drvdata(dev); struct dma_chan *chan, *_chan; /* bring back DMA controller */ clk_prepare_enable(atdma->clk); dma_writel(atdma, EN, AT_DMA_ENABLE); /* clear any pending interrupt */ while (dma_readl(atdma, EBCISR)) cpu_relax(); /* restore saved data */ dma_writel(atdma, EBCIER, atdma->save_imr); list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, device_node) { struct at_dma_chan *atchan = to_at_dma_chan(chan); channel_writel(atchan, CFG, atchan->save_cfg); if (atc_chan_is_cyclic(atchan)) atc_resume_cyclic(atchan); } return 0; } static const struct dev_pm_ops __maybe_unused at_dma_dev_pm_ops = { .prepare = at_dma_prepare, .suspend_noirq = at_dma_suspend_noirq, .resume_noirq = at_dma_resume_noirq, }; static struct platform_driver at_dma_driver = { .remove = at_dma_remove, .shutdown = at_dma_shutdown, .id_table = atdma_devtypes, .driver = { .name = "at_hdmac", .pm = pm_ptr(&at_dma_dev_pm_ops), .of_match_table = of_match_ptr(atmel_dma_dt_ids), }, }; static int __init at_dma_init(void) { return platform_driver_probe(&at_dma_driver, at_dma_probe); } subsys_initcall(at_dma_init); static void __exit at_dma_exit(void) { platform_driver_unregister(&at_dma_driver); } module_exit(at_dma_exit); MODULE_DESCRIPTION("Atmel AHB DMA Controller driver"); MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>"); MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:at_hdmac");
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