// SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2017-2018 MediaTek Inc. /* * Driver for MediaTek High-Speed DMA Controller * * Author: Sean Wang * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../virt-dma.h" #define MTK_HSDMA_USEC_POLL 20 #define MTK_HSDMA_TIMEOUT_POLL 200000 #define MTK_HSDMA_DMA_BUSWIDTHS BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) /* The default number of virtual channel */ #define MTK_HSDMA_NR_VCHANS 3 /* Only one physical channel supported */ #define MTK_HSDMA_NR_MAX_PCHANS 1 /* Macro for physical descriptor (PD) manipulation */ /* The number of PD which must be 2 of power */ #define MTK_DMA_SIZE 64 #define MTK_HSDMA_NEXT_DESP_IDX(x, y) (((x) + 1) & ((y) - 1)) #define MTK_HSDMA_LAST_DESP_IDX(x, y) (((x) - 1) & ((y) - 1)) #define MTK_HSDMA_MAX_LEN 0x3f80 #define MTK_HSDMA_ALIGN_SIZE 4 #define MTK_HSDMA_PLEN_MASK 0x3fff #define MTK_HSDMA_DESC_PLEN(x) (((x) & MTK_HSDMA_PLEN_MASK) << 16) #define MTK_HSDMA_DESC_PLEN_GET(x) (((x) >> 16) & MTK_HSDMA_PLEN_MASK) /* Registers for underlying ring manipulation */ #define MTK_HSDMA_TX_BASE 0x0 #define MTK_HSDMA_TX_CNT 0x4 #define MTK_HSDMA_TX_CPU 0x8 #define MTK_HSDMA_TX_DMA 0xc #define MTK_HSDMA_RX_BASE 0x100 #define MTK_HSDMA_RX_CNT 0x104 #define MTK_HSDMA_RX_CPU 0x108 #define MTK_HSDMA_RX_DMA 0x10c /* Registers for global setup */ #define MTK_HSDMA_GLO 0x204 #define MTK_HSDMA_GLO_MULTI_DMA BIT(10) #define MTK_HSDMA_TX_WB_DDONE BIT(6) #define MTK_HSDMA_BURST_64BYTES (0x2 << 4) #define MTK_HSDMA_GLO_RX_BUSY BIT(3) #define MTK_HSDMA_GLO_RX_DMA BIT(2) #define MTK_HSDMA_GLO_TX_BUSY BIT(1) #define MTK_HSDMA_GLO_TX_DMA BIT(0) #define MTK_HSDMA_GLO_DMA (MTK_HSDMA_GLO_TX_DMA | \ MTK_HSDMA_GLO_RX_DMA) #define MTK_HSDMA_GLO_BUSY (MTK_HSDMA_GLO_RX_BUSY | \ MTK_HSDMA_GLO_TX_BUSY) #define MTK_HSDMA_GLO_DEFAULT (MTK_HSDMA_GLO_TX_DMA | \ MTK_HSDMA_GLO_RX_DMA | \ MTK_HSDMA_TX_WB_DDONE | \ MTK_HSDMA_BURST_64BYTES | \ MTK_HSDMA_GLO_MULTI_DMA) /* Registers for reset */ #define MTK_HSDMA_RESET 0x208 #define MTK_HSDMA_RST_TX BIT(0) #define MTK_HSDMA_RST_RX BIT(16) /* Registers for interrupt control */ #define MTK_HSDMA_DLYINT 0x20c #define MTK_HSDMA_RXDLY_INT_EN BIT(15) /* Interrupt fires when the pending number's more than the specified */ #define MTK_HSDMA_RXMAX_PINT(x) (((x) & 0x7f) << 8) /* Interrupt fires when the pending time's more than the specified in 20 us */ #define MTK_HSDMA_RXMAX_PTIME(x) ((x) & 0x7f) #define MTK_HSDMA_DLYINT_DEFAULT (MTK_HSDMA_RXDLY_INT_EN | \ MTK_HSDMA_RXMAX_PINT(20) | \ MTK_HSDMA_RXMAX_PTIME(20)) #define MTK_HSDMA_INT_STATUS 0x220 #define MTK_HSDMA_INT_ENABLE 0x228 #define MTK_HSDMA_INT_RXDONE BIT(16) enum mtk_hsdma_vdesc_flag { MTK_HSDMA_VDESC_FINISHED = 0x01, }; #define IS_MTK_HSDMA_VDESC_FINISHED(x) ((x) == MTK_HSDMA_VDESC_FINISHED) /** * struct mtk_hsdma_pdesc - This is the struct holding info describing physical * descriptor (PD) and its placement must be kept at * 4-bytes alignment in little endian order. * @desc[1-4]: The control pad used to indicate hardware how to * deal with the descriptor such as source and * destination address and data length. The maximum * data length each pdesc can handle is 0x3f80 bytes */ struct mtk_hsdma_pdesc { __le32 desc1; __le32 desc2; __le32 desc3; __le32 desc4; } __packed __aligned(4); /** * struct mtk_hsdma_vdesc - This is the struct holding info describing virtual * descriptor (VD) * @vd: An instance for struct virt_dma_desc * @len: The total data size device wants to move * @residue: The remaining data size device will move * @dest: The destination address device wants to move to * @src: The source address device wants to move from */ struct mtk_hsdma_vdesc { struct virt_dma_desc vd; size_t len; size_t residue; dma_addr_t dest; dma_addr_t src; }; /** * struct mtk_hsdma_cb - This is the struct holding extra info required for RX * ring to know what relevant VD the the PD is being * mapped to. * @vd: Pointer to the relevant VD. * @flag: Flag indicating what action should be taken when VD * is completed. */ struct mtk_hsdma_cb { struct virt_dma_desc *vd; enum mtk_hsdma_vdesc_flag flag; }; /** * struct mtk_hsdma_ring - This struct holds info describing underlying ring * space * @txd: The descriptor TX ring which describes DMA source * information * @rxd: The descriptor RX ring which describes DMA * destination information * @cb: The extra information pointed at by RX ring * @tphys: The physical addr of TX ring * @rphys: The physical addr of RX ring * @cur_tptr: Pointer to the next free descriptor used by the host * @cur_rptr: Pointer to the last done descriptor by the device */ struct mtk_hsdma_ring { struct mtk_hsdma_pdesc *txd; struct mtk_hsdma_pdesc *rxd; struct mtk_hsdma_cb *cb; dma_addr_t tphys; dma_addr_t rphys; u16 cur_tptr; u16 cur_rptr; }; /** * struct mtk_hsdma_pchan - This is the struct holding info describing physical * channel (PC) * @ring: An instance for the underlying ring * @sz_ring: Total size allocated for the ring * @nr_free: Total number of free rooms in the ring. It would * be accessed and updated frequently between IRQ * context and user context to reflect whether ring * can accept requests from VD. */ struct mtk_hsdma_pchan { struct mtk_hsdma_ring ring; size_t sz_ring; atomic_t nr_free; }; /** * struct mtk_hsdma_vchan - This is the struct holding info describing virtual * channel (VC) * @vc: An instance for struct virt_dma_chan * @issue_completion: The wait for all issued descriptors completited * @issue_synchronize: Bool indicating channel synchronization starts * @desc_hw_processing: List those descriptors the hardware is processing, * which is protected by vc.lock */ struct mtk_hsdma_vchan { struct virt_dma_chan vc; struct completion issue_completion; bool issue_synchronize; struct list_head desc_hw_processing; }; /** * struct mtk_hsdma_soc - This is the struct holding differences among SoCs * @ddone: Bit mask for DDONE * @ls0: Bit mask for LS0 */ struct mtk_hsdma_soc { __le32 ddone; __le32 ls0; }; /** * struct mtk_hsdma_device - This is the struct holding info describing HSDMA * device * @ddev: An instance for struct dma_device * @base: The mapped register I/O base * @clk: The clock that device internal is using * @irq: The IRQ that device are using * @dma_requests: The number of VCs the device supports to * @vc: The pointer to all available VCs * @pc: The pointer to the underlying PC * @pc_refcnt: Track how many VCs are using the PC * @lock: Lock protect agaisting multiple VCs access PC * @soc: The pointer to area holding differences among * vaious platform */ struct mtk_hsdma_device { struct dma_device ddev; void __iomem *base; struct clk *clk; u32 irq; u32 dma_requests; struct mtk_hsdma_vchan *vc; struct mtk_hsdma_pchan *pc; refcount_t pc_refcnt; /* Lock used to protect against multiple VCs access PC */ spinlock_t lock; const struct mtk_hsdma_soc *soc; }; static struct mtk_hsdma_device *to_hsdma_dev(struct dma_chan *chan) { return container_of(chan->device, struct mtk_hsdma_device, ddev); } static inline struct mtk_hsdma_vchan *to_hsdma_vchan(struct dma_chan *chan) { return container_of(chan, struct mtk_hsdma_vchan, vc.chan); } static struct mtk_hsdma_vdesc *to_hsdma_vdesc(struct virt_dma_desc *vd) { return container_of(vd, struct mtk_hsdma_vdesc, vd); } static struct device *hsdma2dev(struct mtk_hsdma_device *hsdma) { return hsdma->ddev.dev; } static u32 mtk_dma_read(struct mtk_hsdma_device *hsdma, u32 reg) { return readl(hsdma->base + reg); } static void mtk_dma_write(struct mtk_hsdma_device *hsdma, u32 reg, u32 val) { writel(val, hsdma->base + reg); } static void mtk_dma_rmw(struct mtk_hsdma_device *hsdma, u32 reg, u32 mask, u32 set) { u32 val; val = mtk_dma_read(hsdma, reg); val &= ~mask; val |= set; mtk_dma_write(hsdma, reg, val); } static void mtk_dma_set(struct mtk_hsdma_device *hsdma, u32 reg, u32 val) { mtk_dma_rmw(hsdma, reg, 0, val); } static void mtk_dma_clr(struct mtk_hsdma_device *hsdma, u32 reg, u32 val) { mtk_dma_rmw(hsdma, reg, val, 0); } static void mtk_hsdma_vdesc_free(struct virt_dma_desc *vd) { kfree(container_of(vd, struct mtk_hsdma_vdesc, vd)); } static int mtk_hsdma_busy_wait(struct mtk_hsdma_device *hsdma) { u32 status = 0; return readl_poll_timeout(hsdma->base + MTK_HSDMA_GLO, status, !(status & MTK_HSDMA_GLO_BUSY), MTK_HSDMA_USEC_POLL, MTK_HSDMA_TIMEOUT_POLL); } static int mtk_hsdma_alloc_pchan(struct mtk_hsdma_device *hsdma, struct mtk_hsdma_pchan *pc) { struct mtk_hsdma_ring *ring = &pc->ring; int err; memset(pc, 0, sizeof(*pc)); /* * Allocate ring space where [0 ... MTK_DMA_SIZE - 1] is for TX ring * and [MTK_DMA_SIZE ... 2 * MTK_DMA_SIZE - 1] is for RX ring. */ pc->sz_ring = 2 * MTK_DMA_SIZE * sizeof(*ring->txd); ring->txd = dma_alloc_coherent(hsdma2dev(hsdma), pc->sz_ring, &ring->tphys, GFP_NOWAIT); if (!ring->txd) return -ENOMEM; ring->rxd = &ring->txd[MTK_DMA_SIZE]; ring->rphys = ring->tphys + MTK_DMA_SIZE * sizeof(*ring->txd); ring->cur_tptr = 0; ring->cur_rptr = MTK_DMA_SIZE - 1; ring->cb = kcalloc(MTK_DMA_SIZE, sizeof(*ring->cb), GFP_NOWAIT); if (!ring->cb) { err = -ENOMEM; goto err_free_dma; } atomic_set(&pc->nr_free, MTK_DMA_SIZE - 1); /* Disable HSDMA and wait for the completion */ mtk_dma_clr(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DMA); err = mtk_hsdma_busy_wait(hsdma); if (err) goto err_free_cb; /* Reset */ mtk_dma_set(hsdma, MTK_HSDMA_RESET, MTK_HSDMA_RST_TX | MTK_HSDMA_RST_RX); mtk_dma_clr(hsdma, MTK_HSDMA_RESET, MTK_HSDMA_RST_TX | MTK_HSDMA_RST_RX); /* Setup HSDMA initial pointer in the ring */ mtk_dma_write(hsdma, MTK_HSDMA_TX_BASE, ring->tphys); mtk_dma_write(hsdma, MTK_HSDMA_TX_CNT, MTK_DMA_SIZE); mtk_dma_write(hsdma, MTK_HSDMA_TX_CPU, ring->cur_tptr); mtk_dma_write(hsdma, MTK_HSDMA_TX_DMA, 0); mtk_dma_write(hsdma, MTK_HSDMA_RX_BASE, ring->rphys); mtk_dma_write(hsdma, MTK_HSDMA_RX_CNT, MTK_DMA_SIZE); mtk_dma_write(hsdma, MTK_HSDMA_RX_CPU, ring->cur_rptr); mtk_dma_write(hsdma, MTK_HSDMA_RX_DMA, 0); /* Enable HSDMA */ mtk_dma_set(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DMA); /* Setup delayed interrupt */ mtk_dma_write(hsdma, MTK_HSDMA_DLYINT, MTK_HSDMA_DLYINT_DEFAULT); /* Enable interrupt */ mtk_dma_set(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE); return 0; err_free_cb: kfree(ring->cb); err_free_dma: dma_free_coherent(hsdma2dev(hsdma), pc->sz_ring, ring->txd, ring->tphys); return err; } static void mtk_hsdma_free_pchan(struct mtk_hsdma_device *hsdma, struct mtk_hsdma_pchan *pc) { struct mtk_hsdma_ring *ring = &pc->ring; /* Disable HSDMA and then wait for the completion */ mtk_dma_clr(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DMA); mtk_hsdma_busy_wait(hsdma); /* Reset pointer in the ring */ mtk_dma_clr(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE); mtk_dma_write(hsdma, MTK_HSDMA_TX_BASE, 0); mtk_dma_write(hsdma, MTK_HSDMA_TX_CNT, 0); mtk_dma_write(hsdma, MTK_HSDMA_TX_CPU, 0); mtk_dma_write(hsdma, MTK_HSDMA_RX_BASE, 0); mtk_dma_write(hsdma, MTK_HSDMA_RX_CNT, 0); mtk_dma_write(hsdma, MTK_HSDMA_RX_CPU, MTK_DMA_SIZE - 1); kfree(ring->cb); dma_free_coherent(hsdma2dev(hsdma), pc->sz_ring, ring->txd, ring->tphys); } static int mtk_hsdma_issue_pending_vdesc(struct mtk_hsdma_device *hsdma, struct mtk_hsdma_pchan *pc, struct mtk_hsdma_vdesc *hvd) { struct mtk_hsdma_ring *ring = &pc->ring; struct mtk_hsdma_pdesc *txd, *rxd; u16 reserved, prev, tlen, num_sgs; unsigned long flags; /* Protect against PC is accessed by multiple VCs simultaneously */ spin_lock_irqsave(&hsdma->lock, flags); /* * Reserve rooms, where pc->nr_free is used to track how many free * rooms in the ring being updated in user and IRQ context. */ num_sgs = DIV_ROUND_UP(hvd->len, MTK_HSDMA_MAX_LEN); reserved = min_t(u16, num_sgs, atomic_read(&pc->nr_free)); if (!reserved) { spin_unlock_irqrestore(&hsdma->lock, flags); return -ENOSPC; } atomic_sub(reserved, &pc->nr_free); while (reserved--) { /* Limit size by PD capability for valid data moving */ tlen = (hvd->len > MTK_HSDMA_MAX_LEN) ? MTK_HSDMA_MAX_LEN : hvd->len; /* * Setup PDs using the remaining VD info mapped on those * reserved rooms. And since RXD is shared memory between the * host and the device allocated by dma_alloc_coherent call, * the helper macro WRITE_ONCE can ensure the data written to * RAM would really happens. */ txd = &ring->txd[ring->cur_tptr]; WRITE_ONCE(txd->desc1, hvd->src); WRITE_ONCE(txd->desc2, hsdma->soc->ls0 | MTK_HSDMA_DESC_PLEN(tlen)); rxd = &ring->rxd[ring->cur_tptr]; WRITE_ONCE(rxd->desc1, hvd->dest); WRITE_ONCE(rxd->desc2, MTK_HSDMA_DESC_PLEN(tlen)); /* Associate VD, the PD belonged to */ ring->cb[ring->cur_tptr].vd = &hvd->vd; /* Move forward the pointer of TX ring */ ring->cur_tptr = MTK_HSDMA_NEXT_DESP_IDX(ring->cur_tptr, MTK_DMA_SIZE); /* Update VD with remaining data */ hvd->src += tlen; hvd->dest += tlen; hvd->len -= tlen; } /* * Tagging flag for the last PD for VD will be responsible for * completing VD. */ if (!hvd->len) { prev = MTK_HSDMA_LAST_DESP_IDX(ring->cur_tptr, MTK_DMA_SIZE); ring->cb[prev].flag = MTK_HSDMA_VDESC_FINISHED; } /* Ensure all changes indeed done before we're going on */ wmb(); /* * Updating into hardware the pointer of TX ring lets HSDMA to take * action for those pending PDs. */ mtk_dma_write(hsdma, MTK_HSDMA_TX_CPU, ring->cur_tptr); spin_unlock_irqrestore(&hsdma->lock, flags); return 0; } static void mtk_hsdma_issue_vchan_pending(struct mtk_hsdma_device *hsdma, struct mtk_hsdma_vchan *hvc) { struct virt_dma_desc *vd, *vd2; int err; lockdep_assert_held(&hvc->vc.lock); list_for_each_entry_safe(vd, vd2, &hvc->vc.desc_issued, node) { struct mtk_hsdma_vdesc *hvd; hvd = to_hsdma_vdesc(vd); /* Map VD into PC and all VCs shares a single PC */ err = mtk_hsdma_issue_pending_vdesc(hsdma, hsdma->pc, hvd); /* * Move VD from desc_issued to desc_hw_processing when entire * VD is fit into available PDs. Otherwise, the uncompleted * VDs would stay in list desc_issued and then restart the * processing as soon as possible once underlying ring space * got freed. */ if (err == -ENOSPC || hvd->len > 0) break; /* * The extra list desc_hw_processing is used because * hardware can't provide sufficient information allowing us * to know what VDs are still working on the underlying ring. * Through the additional list, it can help us to implement * terminate_all, residue calculation and such thing needed * to know detail descriptor status on the hardware. */ list_move_tail(&vd->node, &hvc->desc_hw_processing); } } static void mtk_hsdma_free_rooms_in_ring(struct mtk_hsdma_device *hsdma) { struct mtk_hsdma_vchan *hvc; struct mtk_hsdma_pdesc *rxd; struct mtk_hsdma_vdesc *hvd; struct mtk_hsdma_pchan *pc; struct mtk_hsdma_cb *cb; int i = MTK_DMA_SIZE; __le32 desc2; u32 status; u16 next; /* Read IRQ status */ status = mtk_dma_read(hsdma, MTK_HSDMA_INT_STATUS); if (unlikely(!(status & MTK_HSDMA_INT_RXDONE))) goto rx_done; pc = hsdma->pc; /* * Using a fail-safe loop with iterations of up to MTK_DMA_SIZE to * reclaim these finished descriptors: The most number of PDs the ISR * can handle at one time shouldn't be more than MTK_DMA_SIZE so we * take it as limited count instead of just using a dangerous infinite * poll. */ while (i--) { next = MTK_HSDMA_NEXT_DESP_IDX(pc->ring.cur_rptr, MTK_DMA_SIZE); rxd = &pc->ring.rxd[next]; /* * If MTK_HSDMA_DESC_DDONE is no specified, that means data * moving for the PD is still under going. */ desc2 = READ_ONCE(rxd->desc2); if (!(desc2 & hsdma->soc->ddone)) break; cb = &pc->ring.cb[next]; if (unlikely(!cb->vd)) { dev_err(hsdma2dev(hsdma), "cb->vd cannot be null\n"); break; } /* Update residue of VD the associated PD belonged to */ hvd = to_hsdma_vdesc(cb->vd); hvd->residue -= MTK_HSDMA_DESC_PLEN_GET(rxd->desc2); /* Complete VD until the relevant last PD is finished */ if (IS_MTK_HSDMA_VDESC_FINISHED(cb->flag)) { hvc = to_hsdma_vchan(cb->vd->tx.chan); spin_lock(&hvc->vc.lock); /* Remove VD from list desc_hw_processing */ list_del(&cb->vd->node); /* Add VD into list desc_completed */ vchan_cookie_complete(cb->vd); if (hvc->issue_synchronize && list_empty(&hvc->desc_hw_processing)) { complete(&hvc->issue_completion); hvc->issue_synchronize = false; } spin_unlock(&hvc->vc.lock); cb->flag = 0; } cb->vd = 0; /* * Recycle the RXD with the helper WRITE_ONCE that can ensure * data written into RAM would really happens. */ WRITE_ONCE(rxd->desc1, 0); WRITE_ONCE(rxd->desc2, 0); pc->ring.cur_rptr = next; /* Release rooms */ atomic_inc(&pc->nr_free); } /* Ensure all changes indeed done before we're going on */ wmb(); /* Update CPU pointer for those completed PDs */ mtk_dma_write(hsdma, MTK_HSDMA_RX_CPU, pc->ring.cur_rptr); /* * Acking the pending IRQ allows hardware no longer to keep the used * IRQ line in certain trigger state when software has completed all * the finished physical descriptors. */ if (atomic_read(&pc->nr_free) >= MTK_DMA_SIZE - 1) mtk_dma_write(hsdma, MTK_HSDMA_INT_STATUS, status); /* ASAP handles pending VDs in all VCs after freeing some rooms */ for (i = 0; i < hsdma->dma_requests; i++) { hvc = &hsdma->vc[i]; spin_lock(&hvc->vc.lock); mtk_hsdma_issue_vchan_pending(hsdma, hvc); spin_unlock(&hvc->vc.lock); } rx_done: /* All completed PDs are cleaned up, so enable interrupt again */ mtk_dma_set(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE); } static irqreturn_t mtk_hsdma_irq(int irq, void *devid) { struct mtk_hsdma_device *hsdma = devid; /* * Disable interrupt until all completed PDs are cleaned up in * mtk_hsdma_free_rooms call. */ mtk_dma_clr(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE); mtk_hsdma_free_rooms_in_ring(hsdma); return IRQ_HANDLED; } static struct virt_dma_desc *mtk_hsdma_find_active_desc(struct dma_chan *c, dma_cookie_t cookie) { struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c); struct virt_dma_desc *vd; list_for_each_entry(vd, &hvc->desc_hw_processing, node) if (vd->tx.cookie == cookie) return vd; list_for_each_entry(vd, &hvc->vc.desc_issued, node) if (vd->tx.cookie == cookie) return vd; return NULL; } static enum dma_status mtk_hsdma_tx_status(struct dma_chan *c, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c); struct mtk_hsdma_vdesc *hvd; struct virt_dma_desc *vd; enum dma_status ret; unsigned long flags; size_t bytes = 0; ret = dma_cookie_status(c, cookie, txstate); if (ret == DMA_COMPLETE || !txstate) return ret; spin_lock_irqsave(&hvc->vc.lock, flags); vd = mtk_hsdma_find_active_desc(c, cookie); spin_unlock_irqrestore(&hvc->vc.lock, flags); if (vd) { hvd = to_hsdma_vdesc(vd); bytes = hvd->residue; } dma_set_residue(txstate, bytes); return ret; } static void mtk_hsdma_issue_pending(struct dma_chan *c) { struct mtk_hsdma_device *hsdma = to_hsdma_dev(c); struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c); unsigned long flags; spin_lock_irqsave(&hvc->vc.lock, flags); if (vchan_issue_pending(&hvc->vc)) mtk_hsdma_issue_vchan_pending(hsdma, hvc); spin_unlock_irqrestore(&hvc->vc.lock, flags); } static struct dma_async_tx_descriptor * mtk_hsdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src, size_t len, unsigned long flags) { struct mtk_hsdma_vdesc *hvd; hvd = kzalloc(sizeof(*hvd), GFP_NOWAIT); if (!hvd) return NULL; hvd->len = len; hvd->residue = len; hvd->src = src; hvd->dest = dest; return vchan_tx_prep(to_virt_chan(c), &hvd->vd, flags); } static int mtk_hsdma_free_inactive_desc(struct dma_chan *c) { struct virt_dma_chan *vc = to_virt_chan(c); unsigned long flags; LIST_HEAD(head); spin_lock_irqsave(&vc->lock, flags); list_splice_tail_init(&vc->desc_allocated, &head); list_splice_tail_init(&vc->desc_submitted, &head); list_splice_tail_init(&vc->desc_issued, &head); spin_unlock_irqrestore(&vc->lock, flags); /* At the point, we don't expect users put descriptor into VC again */ vchan_dma_desc_free_list(vc, &head); return 0; } static void mtk_hsdma_free_active_desc(struct dma_chan *c) { struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c); bool sync_needed = false; /* * Once issue_synchronize is being set, which means once the hardware * consumes all descriptors for the channel in the ring, the * synchronization must be be notified immediately it is completed. */ spin_lock(&hvc->vc.lock); if (!list_empty(&hvc->desc_hw_processing)) { hvc->issue_synchronize = true; sync_needed = true; } spin_unlock(&hvc->vc.lock); if (sync_needed) wait_for_completion(&hvc->issue_completion); /* * At the point, we expect that all remaining descriptors in the ring * for the channel should be all processing done. */ WARN_ONCE(!list_empty(&hvc->desc_hw_processing), "Desc pending still in list desc_hw_processing\n"); /* Free all descriptors in list desc_completed */ vchan_synchronize(&hvc->vc); WARN_ONCE(!list_empty(&hvc->vc.desc_completed), "Desc pending still in list desc_completed\n"); } static int mtk_hsdma_terminate_all(struct dma_chan *c) { /* * Free pending descriptors not processed yet by hardware that have * previously been submitted to the channel. */ mtk_hsdma_free_inactive_desc(c); /* * However, the DMA engine doesn't provide any way to stop these * descriptors being processed currently by hardware. The only way is * to just waiting until these descriptors are all processed completely * through mtk_hsdma_free_active_desc call. */ mtk_hsdma_free_active_desc(c); return 0; } static int mtk_hsdma_alloc_chan_resources(struct dma_chan *c) { struct mtk_hsdma_device *hsdma = to_hsdma_dev(c); int err; /* * Since HSDMA has only one PC, the resource for PC is being allocated * when the first VC is being created and the other VCs would run on * the same PC. */ if (!refcount_read(&hsdma->pc_refcnt)) { err = mtk_hsdma_alloc_pchan(hsdma, hsdma->pc); if (err) return err; /* * refcount_inc would complain increment on 0; use-after-free. * Thus, we need to explicitly set it as 1 initially. */ refcount_set(&hsdma->pc_refcnt, 1); } else { refcount_inc(&hsdma->pc_refcnt); } return 0; } static void mtk_hsdma_free_chan_resources(struct dma_chan *c) { struct mtk_hsdma_device *hsdma = to_hsdma_dev(c); /* Free all descriptors in all lists on the VC */ mtk_hsdma_terminate_all(c); /* The resource for PC is not freed until all the VCs are destroyed */ if (!refcount_dec_and_test(&hsdma->pc_refcnt)) return; mtk_hsdma_free_pchan(hsdma, hsdma->pc); } static int mtk_hsdma_hw_init(struct mtk_hsdma_device *hsdma) { int err; pm_runtime_enable(hsdma2dev(hsdma)); pm_runtime_get_sync(hsdma2dev(hsdma)); err = clk_prepare_enable(hsdma->clk); if (err) return err; mtk_dma_write(hsdma, MTK_HSDMA_INT_ENABLE, 0); mtk_dma_write(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DEFAULT); return 0; } static int mtk_hsdma_hw_deinit(struct mtk_hsdma_device *hsdma) { mtk_dma_write(hsdma, MTK_HSDMA_GLO, 0); clk_disable_unprepare(hsdma->clk); pm_runtime_put_sync(hsdma2dev(hsdma)); pm_runtime_disable(hsdma2dev(hsdma)); return 0; } static const struct mtk_hsdma_soc mt7623_soc = { .ddone = BIT(31), .ls0 = BIT(30), }; static const struct mtk_hsdma_soc mt7622_soc = { .ddone = BIT(15), .ls0 = BIT(14), }; static const struct of_device_id mtk_hsdma_match[] = { { .compatible = "mediatek,mt7623-hsdma", .data = &mt7623_soc}, { .compatible = "mediatek,mt7622-hsdma", .data = &mt7622_soc}, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, mtk_hsdma_match); static int mtk_hsdma_probe(struct platform_device *pdev) { struct mtk_hsdma_device *hsdma; struct mtk_hsdma_vchan *vc; struct dma_device *dd; struct resource *res; int i, err; hsdma = devm_kzalloc(&pdev->dev, sizeof(*hsdma), GFP_KERNEL); if (!hsdma) return -ENOMEM; dd = &hsdma->ddev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); hsdma->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(hsdma->base)) return PTR_ERR(hsdma->base); hsdma->soc = of_device_get_match_data(&pdev->dev); if (!hsdma->soc) { dev_err(&pdev->dev, "No device match found\n"); return -ENODEV; } hsdma->clk = devm_clk_get(&pdev->dev, "hsdma"); if (IS_ERR(hsdma->clk)) { dev_err(&pdev->dev, "No clock for %s\n", dev_name(&pdev->dev)); return PTR_ERR(hsdma->clk); } res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (!res) { dev_err(&pdev->dev, "No irq resource for %s\n", dev_name(&pdev->dev)); return -EINVAL; } hsdma->irq = res->start; refcount_set(&hsdma->pc_refcnt, 0); spin_lock_init(&hsdma->lock); dma_cap_set(DMA_MEMCPY, dd->cap_mask); dd->copy_align = MTK_HSDMA_ALIGN_SIZE; dd->device_alloc_chan_resources = mtk_hsdma_alloc_chan_resources; dd->device_free_chan_resources = mtk_hsdma_free_chan_resources; dd->device_tx_status = mtk_hsdma_tx_status; dd->device_issue_pending = mtk_hsdma_issue_pending; dd->device_prep_dma_memcpy = mtk_hsdma_prep_dma_memcpy; dd->device_terminate_all = mtk_hsdma_terminate_all; dd->src_addr_widths = MTK_HSDMA_DMA_BUSWIDTHS; dd->dst_addr_widths = MTK_HSDMA_DMA_BUSWIDTHS; dd->directions = BIT(DMA_MEM_TO_MEM); dd->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT; dd->dev = &pdev->dev; INIT_LIST_HEAD(&dd->channels); hsdma->dma_requests = MTK_HSDMA_NR_VCHANS; if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node, "dma-requests", &hsdma->dma_requests)) { dev_info(&pdev->dev, "Using %u as missing dma-requests property\n", MTK_HSDMA_NR_VCHANS); } hsdma->pc = devm_kcalloc(&pdev->dev, MTK_HSDMA_NR_MAX_PCHANS, sizeof(*hsdma->pc), GFP_KERNEL); if (!hsdma->pc) return -ENOMEM; hsdma->vc = devm_kcalloc(&pdev->dev, hsdma->dma_requests, sizeof(*hsdma->vc), GFP_KERNEL); if (!hsdma->vc) return -ENOMEM; for (i = 0; i < hsdma->dma_requests; i++) { vc = &hsdma->vc[i]; vc->vc.desc_free = mtk_hsdma_vdesc_free; vchan_init(&vc->vc, dd); init_completion(&vc->issue_completion); INIT_LIST_HEAD(&vc->desc_hw_processing); } err = dma_async_device_register(dd); if (err) return err; err = of_dma_controller_register(pdev->dev.of_node, of_dma_xlate_by_chan_id, hsdma); if (err) { dev_err(&pdev->dev, "MediaTek HSDMA OF registration failed %d\n", err); goto err_unregister; } mtk_hsdma_hw_init(hsdma); err = devm_request_irq(&pdev->dev, hsdma->irq, mtk_hsdma_irq, 0, dev_name(&pdev->dev), hsdma); if (err) { dev_err(&pdev->dev, "request_irq failed with err %d\n", err); goto err_unregister; } platform_set_drvdata(pdev, hsdma); dev_info(&pdev->dev, "MediaTek HSDMA driver registered\n"); return 0; err_unregister: dma_async_device_unregister(dd); return err; } static int mtk_hsdma_remove(struct platform_device *pdev) { struct mtk_hsdma_device *hsdma = platform_get_drvdata(pdev); struct mtk_hsdma_vchan *vc; int i; /* Kill VC task */ for (i = 0; i < hsdma->dma_requests; i++) { vc = &hsdma->vc[i]; list_del(&vc->vc.chan.device_node); tasklet_kill(&vc->vc.task); } /* Disable DMA interrupt */ mtk_dma_write(hsdma, MTK_HSDMA_INT_ENABLE, 0); /* Waits for any pending IRQ handlers to complete */ synchronize_irq(hsdma->irq); /* Disable hardware */ mtk_hsdma_hw_deinit(hsdma); dma_async_device_unregister(&hsdma->ddev); of_dma_controller_free(pdev->dev.of_node); return 0; } static struct platform_driver mtk_hsdma_driver = { .probe = mtk_hsdma_probe, .remove = mtk_hsdma_remove, .driver = { .name = KBUILD_MODNAME, .of_match_table = mtk_hsdma_match, }, }; module_platform_driver(mtk_hsdma_driver); MODULE_DESCRIPTION("MediaTek High-Speed DMA Controller Driver"); MODULE_AUTHOR("Sean Wang "); MODULE_LICENSE("GPL v2");