diff options
Diffstat (limited to 'drivers/dma/owl-dma.c')
| -rw-r--r-- | drivers/dma/owl-dma.c | 971 |
1 files changed, 971 insertions, 0 deletions
diff --git a/drivers/dma/owl-dma.c b/drivers/dma/owl-dma.c new file mode 100644 index 000000000000..7812a6338acd --- /dev/null +++ b/drivers/dma/owl-dma.c @@ -0,0 +1,971 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Actions Semi Owl SoCs DMA driver +// +// Copyright (c) 2014 Actions Semi Inc. +// Author: David Liu <liuwei@actions-semi.com> +// +// Copyright (c) 2018 Linaro Ltd. +// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> + +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/dmapool.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/slab.h> +#include "virt-dma.h" + +#define OWL_DMA_FRAME_MAX_LENGTH 0xfffff + +/* Global DMA Controller Registers */ +#define OWL_DMA_IRQ_PD0 0x00 +#define OWL_DMA_IRQ_PD1 0x04 +#define OWL_DMA_IRQ_PD2 0x08 +#define OWL_DMA_IRQ_PD3 0x0C +#define OWL_DMA_IRQ_EN0 0x10 +#define OWL_DMA_IRQ_EN1 0x14 +#define OWL_DMA_IRQ_EN2 0x18 +#define OWL_DMA_IRQ_EN3 0x1C +#define OWL_DMA_SECURE_ACCESS_CTL 0x20 +#define OWL_DMA_NIC_QOS 0x24 +#define OWL_DMA_DBGSEL 0x28 +#define OWL_DMA_IDLE_STAT 0x2C + +/* Channel Registers */ +#define OWL_DMA_CHAN_BASE(i) (0x100 + (i) * 0x100) +#define OWL_DMAX_MODE 0x00 +#define OWL_DMAX_SOURCE 0x04 +#define OWL_DMAX_DESTINATION 0x08 +#define OWL_DMAX_FRAME_LEN 0x0C +#define OWL_DMAX_FRAME_CNT 0x10 +#define OWL_DMAX_REMAIN_FRAME_CNT 0x14 +#define OWL_DMAX_REMAIN_CNT 0x18 +#define OWL_DMAX_SOURCE_STRIDE 0x1C +#define OWL_DMAX_DESTINATION_STRIDE 0x20 +#define OWL_DMAX_START 0x24 +#define OWL_DMAX_PAUSE 0x28 +#define OWL_DMAX_CHAINED_CTL 0x2C +#define OWL_DMAX_CONSTANT 0x30 +#define OWL_DMAX_LINKLIST_CTL 0x34 +#define OWL_DMAX_NEXT_DESCRIPTOR 0x38 +#define OWL_DMAX_CURRENT_DESCRIPTOR_NUM 0x3C +#define OWL_DMAX_INT_CTL 0x40 +#define OWL_DMAX_INT_STATUS 0x44 +#define OWL_DMAX_CURRENT_SOURCE_POINTER 0x48 +#define OWL_DMAX_CURRENT_DESTINATION_POINTER 0x4C + +/* OWL_DMAX_MODE Bits */ +#define OWL_DMA_MODE_TS(x) (((x) & GENMASK(5, 0)) << 0) +#define OWL_DMA_MODE_ST(x) (((x) & GENMASK(1, 0)) << 8) +#define OWL_DMA_MODE_ST_DEV OWL_DMA_MODE_ST(0) +#define OWL_DMA_MODE_ST_DCU OWL_DMA_MODE_ST(2) +#define OWL_DMA_MODE_ST_SRAM OWL_DMA_MODE_ST(3) +#define OWL_DMA_MODE_DT(x) (((x) & GENMASK(1, 0)) << 10) +#define OWL_DMA_MODE_DT_DEV OWL_DMA_MODE_DT(0) +#define OWL_DMA_MODE_DT_DCU OWL_DMA_MODE_DT(2) +#define OWL_DMA_MODE_DT_SRAM OWL_DMA_MODE_DT(3) +#define OWL_DMA_MODE_SAM(x) (((x) & GENMASK(1, 0)) << 16) +#define OWL_DMA_MODE_SAM_CONST OWL_DMA_MODE_SAM(0) +#define OWL_DMA_MODE_SAM_INC OWL_DMA_MODE_SAM(1) +#define OWL_DMA_MODE_SAM_STRIDE OWL_DMA_MODE_SAM(2) +#define OWL_DMA_MODE_DAM(x) (((x) & GENMASK(1, 0)) << 18) +#define OWL_DMA_MODE_DAM_CONST OWL_DMA_MODE_DAM(0) +#define OWL_DMA_MODE_DAM_INC OWL_DMA_MODE_DAM(1) +#define OWL_DMA_MODE_DAM_STRIDE OWL_DMA_MODE_DAM(2) +#define OWL_DMA_MODE_PW(x) (((x) & GENMASK(2, 0)) << 20) +#define OWL_DMA_MODE_CB BIT(23) +#define OWL_DMA_MODE_NDDBW(x) (((x) & 0x1) << 28) +#define OWL_DMA_MODE_NDDBW_32BIT OWL_DMA_MODE_NDDBW(0) +#define OWL_DMA_MODE_NDDBW_8BIT OWL_DMA_MODE_NDDBW(1) +#define OWL_DMA_MODE_CFE BIT(29) +#define OWL_DMA_MODE_LME BIT(30) +#define OWL_DMA_MODE_CME BIT(31) + +/* OWL_DMAX_LINKLIST_CTL Bits */ +#define OWL_DMA_LLC_SAV(x) (((x) & GENMASK(1, 0)) << 8) +#define OWL_DMA_LLC_SAV_INC OWL_DMA_LLC_SAV(0) +#define OWL_DMA_LLC_SAV_LOAD_NEXT OWL_DMA_LLC_SAV(1) +#define OWL_DMA_LLC_SAV_LOAD_PREV OWL_DMA_LLC_SAV(2) +#define OWL_DMA_LLC_DAV(x) (((x) & GENMASK(1, 0)) << 10) +#define OWL_DMA_LLC_DAV_INC OWL_DMA_LLC_DAV(0) +#define OWL_DMA_LLC_DAV_LOAD_NEXT OWL_DMA_LLC_DAV(1) +#define OWL_DMA_LLC_DAV_LOAD_PREV OWL_DMA_LLC_DAV(2) +#define OWL_DMA_LLC_SUSPEND BIT(16) + +/* OWL_DMAX_INT_CTL Bits */ +#define OWL_DMA_INTCTL_BLOCK BIT(0) +#define OWL_DMA_INTCTL_SUPER_BLOCK BIT(1) +#define OWL_DMA_INTCTL_FRAME BIT(2) +#define OWL_DMA_INTCTL_HALF_FRAME BIT(3) +#define OWL_DMA_INTCTL_LAST_FRAME BIT(4) + +/* OWL_DMAX_INT_STATUS Bits */ +#define OWL_DMA_INTSTAT_BLOCK BIT(0) +#define OWL_DMA_INTSTAT_SUPER_BLOCK BIT(1) +#define OWL_DMA_INTSTAT_FRAME BIT(2) +#define OWL_DMA_INTSTAT_HALF_FRAME BIT(3) +#define OWL_DMA_INTSTAT_LAST_FRAME BIT(4) + +/* Pack shift and newshift in a single word */ +#define BIT_FIELD(val, width, shift, newshift) \ + ((((val) >> (shift)) & ((BIT(width)) - 1)) << (newshift)) + +/** + * struct owl_dma_lli_hw - Hardware link list for dma transfer + * @next_lli: physical address of the next link list + * @saddr: source physical address + * @daddr: destination physical address + * @flen: frame length + * @fcnt: frame count + * @src_stride: source stride + * @dst_stride: destination stride + * @ctrla: dma_mode and linklist ctrl config + * @ctrlb: interrupt config + * @const_num: data for constant fill + */ +struct owl_dma_lli_hw { + u32 next_lli; + u32 saddr; + u32 daddr; + u32 flen:20; + u32 fcnt:12; + u32 src_stride; + u32 dst_stride; + u32 ctrla; + u32 ctrlb; + u32 const_num; +}; + +/** + * struct owl_dma_lli - Link list for dma transfer + * @hw: hardware link list + * @phys: physical address of hardware link list + * @node: node for txd's lli_list + */ +struct owl_dma_lli { + struct owl_dma_lli_hw hw; + dma_addr_t phys; + struct list_head node; +}; + +/** + * struct owl_dma_txd - Wrapper for struct dma_async_tx_descriptor + * @vd: virtual DMA descriptor + * @lli_list: link list of lli nodes + */ +struct owl_dma_txd { + struct virt_dma_desc vd; + struct list_head lli_list; +}; + +/** + * struct owl_dma_pchan - Holder for the physical channels + * @id: physical index to this channel + * @base: virtual memory base for the dma channel + * @vchan: the virtual channel currently being served by this physical channel + * @lock: a lock to use when altering an instance of this struct + */ +struct owl_dma_pchan { + u32 id; + void __iomem *base; + struct owl_dma_vchan *vchan; + spinlock_t lock; +}; + +/** + * struct owl_dma_pchan - Wrapper for DMA ENGINE channel + * @vc: wrappped virtual channel + * @pchan: the physical channel utilized by this channel + * @txd: active transaction on this channel + */ +struct owl_dma_vchan { + struct virt_dma_chan vc; + struct owl_dma_pchan *pchan; + struct owl_dma_txd *txd; +}; + +/** + * struct owl_dma - Holder for the Owl DMA controller + * @dma: dma engine for this instance + * @base: virtual memory base for the DMA controller + * @clk: clock for the DMA controller + * @lock: a lock to use when change DMA controller global register + * @lli_pool: a pool for the LLI descriptors + * @nr_pchans: the number of physical channels + * @pchans: array of data for the physical channels + * @nr_vchans: the number of physical channels + * @vchans: array of data for the physical channels + */ +struct owl_dma { + struct dma_device dma; + void __iomem *base; + struct clk *clk; + spinlock_t lock; + struct dma_pool *lli_pool; + int irq; + + unsigned int nr_pchans; + struct owl_dma_pchan *pchans; + + unsigned int nr_vchans; + struct owl_dma_vchan *vchans; +}; + +static void pchan_update(struct owl_dma_pchan *pchan, u32 reg, + u32 val, bool state) +{ + u32 regval; + + regval = readl(pchan->base + reg); + + if (state) + regval |= val; + else + regval &= ~val; + + writel(val, pchan->base + reg); +} + +static void pchan_writel(struct owl_dma_pchan *pchan, u32 reg, u32 data) +{ + writel(data, pchan->base + reg); +} + +static u32 pchan_readl(struct owl_dma_pchan *pchan, u32 reg) +{ + return readl(pchan->base + reg); +} + +static void dma_update(struct owl_dma *od, u32 reg, u32 val, bool state) +{ + u32 regval; + + regval = readl(od->base + reg); + + if (state) + regval |= val; + else + regval &= ~val; + + writel(val, od->base + reg); +} + +static void dma_writel(struct owl_dma *od, u32 reg, u32 data) +{ + writel(data, od->base + reg); +} + +static u32 dma_readl(struct owl_dma *od, u32 reg) +{ + return readl(od->base + reg); +} + +static inline struct owl_dma *to_owl_dma(struct dma_device *dd) +{ + return container_of(dd, struct owl_dma, dma); +} + +static struct device *chan2dev(struct dma_chan *chan) +{ + return &chan->dev->device; +} + +static inline struct owl_dma_vchan *to_owl_vchan(struct dma_chan *chan) +{ + return container_of(chan, struct owl_dma_vchan, vc.chan); +} + +static inline struct owl_dma_txd *to_owl_txd(struct dma_async_tx_descriptor *tx) +{ + return container_of(tx, struct owl_dma_txd, vd.tx); +} + +static inline u32 llc_hw_ctrla(u32 mode, u32 llc_ctl) +{ + u32 ctl; + + ctl = BIT_FIELD(mode, 4, 28, 28) | + BIT_FIELD(mode, 8, 16, 20) | + BIT_FIELD(mode, 4, 8, 16) | + BIT_FIELD(mode, 6, 0, 10) | + BIT_FIELD(llc_ctl, 2, 10, 8) | + BIT_FIELD(llc_ctl, 2, 8, 6); + + return ctl; +} + +static inline u32 llc_hw_ctrlb(u32 int_ctl) +{ + u32 ctl; + + ctl = BIT_FIELD(int_ctl, 7, 0, 18); + + return ctl; +} + +static void owl_dma_free_lli(struct owl_dma *od, + struct owl_dma_lli *lli) +{ + list_del(&lli->node); + dma_pool_free(od->lli_pool, lli, lli->phys); +} + +static struct owl_dma_lli *owl_dma_alloc_lli(struct owl_dma *od) +{ + struct owl_dma_lli *lli; + dma_addr_t phys; + + lli = dma_pool_alloc(od->lli_pool, GFP_NOWAIT, &phys); + if (!lli) + return NULL; + + INIT_LIST_HEAD(&lli->node); + lli->phys = phys; + + return lli; +} + +static struct owl_dma_lli *owl_dma_add_lli(struct owl_dma_txd *txd, + struct owl_dma_lli *prev, + struct owl_dma_lli *next) +{ + list_add_tail(&next->node, &txd->lli_list); + + if (prev) { + prev->hw.next_lli = next->phys; + prev->hw.ctrla |= llc_hw_ctrla(OWL_DMA_MODE_LME, 0); + } + + return next; +} + +static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan, + struct owl_dma_lli *lli, + dma_addr_t src, dma_addr_t dst, + u32 len, enum dma_transfer_direction dir) +{ + struct owl_dma_lli_hw *hw = &lli->hw; + u32 mode; + + mode = OWL_DMA_MODE_PW(0); + + switch (dir) { + case DMA_MEM_TO_MEM: + mode |= OWL_DMA_MODE_TS(0) | OWL_DMA_MODE_ST_DCU | + OWL_DMA_MODE_DT_DCU | OWL_DMA_MODE_SAM_INC | + OWL_DMA_MODE_DAM_INC; + + break; + default: + return -EINVAL; + } + + hw->next_lli = 0; /* One link list by default */ + hw->saddr = src; + hw->daddr = dst; + + hw->fcnt = 1; /* Frame count fixed as 1 */ + hw->flen = len; /* Max frame length is 1MB */ + hw->src_stride = 0; + hw->dst_stride = 0; + hw->ctrla = llc_hw_ctrla(mode, + OWL_DMA_LLC_SAV_LOAD_NEXT | + OWL_DMA_LLC_DAV_LOAD_NEXT); + + hw->ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_SUPER_BLOCK); + + return 0; +} + +static struct owl_dma_pchan *owl_dma_get_pchan(struct owl_dma *od, + struct owl_dma_vchan *vchan) +{ + struct owl_dma_pchan *pchan = NULL; + unsigned long flags; + int i; + + for (i = 0; i < od->nr_pchans; i++) { + pchan = &od->pchans[i]; + + spin_lock_irqsave(&pchan->lock, flags); + if (!pchan->vchan) { + pchan->vchan = vchan; + spin_unlock_irqrestore(&pchan->lock, flags); + break; + } + + spin_unlock_irqrestore(&pchan->lock, flags); + } + + return pchan; +} + +static int owl_dma_pchan_busy(struct owl_dma *od, struct owl_dma_pchan *pchan) +{ + unsigned int val; + + val = dma_readl(od, OWL_DMA_IDLE_STAT); + + return !(val & (1 << pchan->id)); +} + +static void owl_dma_terminate_pchan(struct owl_dma *od, + struct owl_dma_pchan *pchan) +{ + unsigned long flags; + u32 irq_pd; + + pchan_writel(pchan, OWL_DMAX_START, 0); + pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false); + + spin_lock_irqsave(&od->lock, flags); + dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), false); + + irq_pd = dma_readl(od, OWL_DMA_IRQ_PD0); + if (irq_pd & (1 << pchan->id)) { + dev_warn(od->dma.dev, + "terminating pchan %d that still has pending irq\n", + pchan->id); + dma_writel(od, OWL_DMA_IRQ_PD0, (1 << pchan->id)); + } + + pchan->vchan = NULL; + + spin_unlock_irqrestore(&od->lock, flags); +} + +static int owl_dma_start_next_txd(struct owl_dma_vchan *vchan) +{ + struct owl_dma *od = to_owl_dma(vchan->vc.chan.device); + struct virt_dma_desc *vd = vchan_next_desc(&vchan->vc); + struct owl_dma_pchan *pchan = vchan->pchan; + struct owl_dma_txd *txd = to_owl_txd(&vd->tx); + struct owl_dma_lli *lli; + unsigned long flags; + u32 int_ctl; + + list_del(&vd->node); + + vchan->txd = txd; + + /* Wait for channel inactive */ + while (owl_dma_pchan_busy(od, pchan)) + cpu_relax(); + + lli = list_first_entry(&txd->lli_list, + struct owl_dma_lli, node); + + int_ctl = OWL_DMA_INTCTL_SUPER_BLOCK; + + pchan_writel(pchan, OWL_DMAX_MODE, OWL_DMA_MODE_LME); + pchan_writel(pchan, OWL_DMAX_LINKLIST_CTL, + OWL_DMA_LLC_SAV_LOAD_NEXT | OWL_DMA_LLC_DAV_LOAD_NEXT); + pchan_writel(pchan, OWL_DMAX_NEXT_DESCRIPTOR, lli->phys); + pchan_writel(pchan, OWL_DMAX_INT_CTL, int_ctl); + + /* Clear IRQ status for this pchan */ + pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false); + + spin_lock_irqsave(&od->lock, flags); + + dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), true); + + spin_unlock_irqrestore(&od->lock, flags); + + dev_dbg(chan2dev(&vchan->vc.chan), "starting pchan %d\n", pchan->id); + + /* Start DMA transfer for this pchan */ + pchan_writel(pchan, OWL_DMAX_START, 0x1); + + return 0; +} + +static void owl_dma_phy_free(struct owl_dma *od, struct owl_dma_vchan *vchan) +{ + /* Ensure that the physical channel is stopped */ + owl_dma_terminate_pchan(od, vchan->pchan); + + vchan->pchan = NULL; +} + +static irqreturn_t owl_dma_interrupt(int irq, void *dev_id) +{ + struct owl_dma *od = dev_id; + struct owl_dma_vchan *vchan; + struct owl_dma_pchan *pchan; + unsigned long pending; + int i; + unsigned int global_irq_pending, chan_irq_pending; + + spin_lock(&od->lock); + + pending = dma_readl(od, OWL_DMA_IRQ_PD0); + + /* Clear IRQ status for each pchan */ + for_each_set_bit(i, &pending, od->nr_pchans) { + pchan = &od->pchans[i]; + pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false); + } + + /* Clear pending IRQ */ + dma_writel(od, OWL_DMA_IRQ_PD0, pending); + + /* Check missed pending IRQ */ + for (i = 0; i < od->nr_pchans; i++) { + pchan = &od->pchans[i]; + chan_irq_pending = pchan_readl(pchan, OWL_DMAX_INT_CTL) & + pchan_readl(pchan, OWL_DMAX_INT_STATUS); + + /* Dummy read to ensure OWL_DMA_IRQ_PD0 value is updated */ + dma_readl(od, OWL_DMA_IRQ_PD0); + + global_irq_pending = dma_readl(od, OWL_DMA_IRQ_PD0); + + if (chan_irq_pending && !(global_irq_pending & BIT(i))) { + dev_dbg(od->dma.dev, + "global and channel IRQ pending match err\n"); + + /* Clear IRQ status for this pchan */ + pchan_update(pchan, OWL_DMAX_INT_STATUS, + 0xff, false); + + /* Update global IRQ pending */ + pending |= BIT(i); + } + } + + spin_unlock(&od->lock); + + for_each_set_bit(i, &pending, od->nr_pchans) { + struct owl_dma_txd *txd; + + pchan = &od->pchans[i]; + + vchan = pchan->vchan; + if (!vchan) { + dev_warn(od->dma.dev, "no vchan attached on pchan %d\n", + pchan->id); + continue; + } + + spin_lock(&vchan->vc.lock); + + txd = vchan->txd; + if (txd) { + vchan->txd = NULL; + + vchan_cookie_complete(&txd->vd); + + /* + * Start the next descriptor (if any), + * otherwise free this channel. + */ + if (vchan_next_desc(&vchan->vc)) + owl_dma_start_next_txd(vchan); + else + owl_dma_phy_free(od, vchan); + } + + spin_unlock(&vchan->vc.lock); + } + + return IRQ_HANDLED; +} + +static void owl_dma_free_txd(struct owl_dma *od, struct owl_dma_txd *txd) +{ + struct owl_dma_lli *lli, *_lli; + + if (unlikely(!txd)) + return; + + list_for_each_entry_safe(lli, _lli, &txd->lli_list, node) + owl_dma_free_lli(od, lli); + + kfree(txd); +} + +static void owl_dma_desc_free(struct virt_dma_desc *vd) +{ + struct owl_dma *od = to_owl_dma(vd->tx.chan->device); + struct owl_dma_txd *txd = to_owl_txd(&vd->tx); + + owl_dma_free_txd(od, txd); +} + +static int owl_dma_terminate_all(struct dma_chan *chan) +{ + struct owl_dma *od = to_owl_dma(chan->device); + struct owl_dma_vchan *vchan = to_owl_vchan(chan); + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&vchan->vc.lock, flags); + + if (vchan->pchan) + owl_dma_phy_free(od, vchan); + + if (vchan->txd) { + owl_dma_desc_free(&vchan->txd->vd); + vchan->txd = NULL; + } + + vchan_get_all_descriptors(&vchan->vc, &head); + vchan_dma_desc_free_list(&vchan->vc, &head); + + spin_unlock_irqrestore(&vchan->vc.lock, flags); + + return 0; +} + +static u32 owl_dma_getbytes_chan(struct owl_dma_vchan *vchan) +{ + struct owl_dma_pchan *pchan; + struct owl_dma_txd *txd; + struct owl_dma_lli *lli; + unsigned int next_lli_phy; + size_t bytes; + + pchan = vchan->pchan; + txd = vchan->txd; + + if (!pchan || !txd) + return 0; + + /* Get remain count of current node in link list */ + bytes = pchan_readl(pchan, OWL_DMAX_REMAIN_CNT); + + /* Loop through the preceding nodes to get total remaining bytes */ + if (pchan_readl(pchan, OWL_DMAX_MODE) & OWL_DMA_MODE_LME) { + next_lli_phy = pchan_readl(pchan, OWL_DMAX_NEXT_DESCRIPTOR); + list_for_each_entry(lli, &txd->lli_list, node) { + /* Start from the next active node */ + if (lli->phys == next_lli_phy) { + list_for_each_entry(lli, &txd->lli_list, node) + bytes += lli->hw.flen; + break; + } + } + } + + return bytes; +} + +static enum dma_status owl_dma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *state) +{ + struct owl_dma_vchan *vchan = to_owl_vchan(chan); + struct owl_dma_lli *lli; + struct virt_dma_desc *vd; + struct owl_dma_txd *txd; + enum dma_status ret; + unsigned long flags; + size_t bytes = 0; + + ret = dma_cookie_status(chan, cookie, state); + if (ret == DMA_COMPLETE || !state) + return ret; + + spin_lock_irqsave(&vchan->vc.lock, flags); + + vd = vchan_find_desc(&vchan->vc, cookie); + if (vd) { + txd = to_owl_txd(&vd->tx); + list_for_each_entry(lli, &txd->lli_list, node) + bytes += lli->hw.flen; + } else { + bytes = owl_dma_getbytes_chan(vchan); + } + + spin_unlock_irqrestore(&vchan->vc.lock, flags); + + dma_set_residue(state, bytes); + + return ret; +} + +static void owl_dma_phy_alloc_and_start(struct owl_dma_vchan *vchan) +{ + struct owl_dma *od = to_owl_dma(vchan->vc.chan.device); + struct owl_dma_pchan *pchan; + + pchan = owl_dma_get_pchan(od, vchan); + if (!pchan) + return; + + dev_dbg(od->dma.dev, "allocated pchan %d\n", pchan->id); + + vchan->pchan = pchan; + owl_dma_start_next_txd(vchan); +} + +static void owl_dma_issue_pending(struct dma_chan *chan) +{ + struct owl_dma_vchan *vchan = to_owl_vchan(chan); + unsigned long flags; + + spin_lock_irqsave(&vchan->vc.lock, flags); + if (vchan_issue_pending(&vchan->vc)) { + if (!vchan->pchan) + owl_dma_phy_alloc_and_start(vchan); + } + spin_unlock_irqrestore(&vchan->vc.lock, flags); +} + +static struct dma_async_tx_descriptor + *owl_dma_prep_memcpy(struct dma_chan *chan, + dma_addr_t dst, dma_addr_t src, + size_t len, unsigned long flags) +{ + struct owl_dma *od = to_owl_dma(chan->device); + struct owl_dma_vchan *vchan = to_owl_vchan(chan); + struct owl_dma_txd *txd; + struct owl_dma_lli *lli, *prev = NULL; + size_t offset, bytes; + int ret; + + if (!len) + return NULL; + + txd = kzalloc(sizeof(*txd), GFP_NOWAIT); + if (!txd) + return NULL; + + INIT_LIST_HEAD(&txd->lli_list); + + /* Process the transfer as frame by frame */ + for (offset = 0; offset < len; offset += bytes) { + lli = owl_dma_alloc_lli(od); + if (!lli) { + dev_warn(chan2dev(chan), "failed to allocate lli\n"); + goto err_txd_free; + } + + bytes = min_t(size_t, (len - offset), OWL_DMA_FRAME_MAX_LENGTH); + + ret = owl_dma_cfg_lli(vchan, lli, src + offset, dst + offset, + bytes, DMA_MEM_TO_MEM); + if (ret) { + dev_warn(chan2dev(chan), "failed to config lli\n"); + goto err_txd_free; + } + + prev = owl_dma_add_lli(txd, prev, lli); + } + + return vchan_tx_prep(&vchan->vc, &txd->vd, flags); + +err_txd_free: + owl_dma_free_txd(od, txd); + return NULL; +} + +static void owl_dma_free_chan_resources(struct dma_chan *chan) +{ + struct owl_dma_vchan *vchan = to_owl_vchan(chan); + + /* Ensure all queued descriptors are freed */ + vchan_free_chan_resources(&vchan->vc); +} + +static inline void owl_dma_free(struct owl_dma *od) +{ + struct owl_dma_vchan *vchan = NULL; + struct owl_dma_vchan *next; + + list_for_each_entry_safe(vchan, + next, &od->dma.channels, vc.chan.device_node) { + list_del(&vchan->vc.chan.device_node); + tasklet_kill(&vchan->vc.task); + } +} + +static int owl_dma_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct owl_dma *od; + struct resource *res; + int ret, i, nr_channels, nr_requests; + + od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL); + if (!od) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -EINVAL; + + od->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(od->base)) + return PTR_ERR(od->base); + + ret = of_property_read_u32(np, "dma-channels", &nr_channels); + if (ret) { + dev_err(&pdev->dev, "can't get dma-channels\n"); + return ret; + } + + ret = of_property_read_u32(np, "dma-requests", &nr_requests); + if (ret) { + dev_err(&pdev->dev, "can't get dma-requests\n"); + return ret; + } + + dev_info(&pdev->dev, "dma-channels %d, dma-requests %d\n", + nr_channels, nr_requests); + + od->nr_pchans = nr_channels; + od->nr_vchans = nr_requests; + + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); + + platform_set_drvdata(pdev, od); + spin_lock_init(&od->lock); + + dma_cap_set(DMA_MEMCPY, od->dma.cap_mask); + + od->dma.dev = &pdev->dev; + od->dma.device_free_chan_resources = owl_dma_free_chan_resources; + od->dma.device_tx_status = owl_dma_tx_status; + od->dma.device_issue_pending = owl_dma_issue_pending; + od->dma.device_prep_dma_memcpy = owl_dma_prep_memcpy; + od->dma.device_terminate_all = owl_dma_terminate_all; + od->dma.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + od->dma.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + od->dma.directions = BIT(DMA_MEM_TO_MEM); + od->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + + INIT_LIST_HEAD(&od->dma.channels); + + od->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(od->clk)) { + dev_err(&pdev->dev, "unable to get clock\n"); + return PTR_ERR(od->clk); + } + + /* + * Eventhough the DMA controller is capable of generating 4 + * IRQ's for DMA priority feature, we only use 1 IRQ for + * simplification. + */ + od->irq = platform_get_irq(pdev, 0); + ret = devm_request_irq(&pdev->dev, od->irq, owl_dma_interrupt, 0, + dev_name(&pdev->dev), od); + if (ret) { + dev_err(&pdev->dev, "unable to request IRQ\n"); + return ret; + } + + /* Init physical channel */ + od->pchans = devm_kcalloc(&pdev->dev, od->nr_pchans, + sizeof(struct owl_dma_pchan), GFP_KERNEL); + if (!od->pchans) + return -ENOMEM; + + for (i = 0; i < od->nr_pchans; i++) { + struct owl_dma_pchan *pchan = &od->pchans[i]; + + pchan->id = i; + pchan->base = od->base + OWL_DMA_CHAN_BASE(i); + } + + /* Init virtual channel */ + od->vchans = devm_kcalloc(&pdev->dev, od->nr_vchans, + sizeof(struct owl_dma_vchan), GFP_KERNEL); + if (!od->vchans) + return -ENOMEM; + + for (i = 0; i < od->nr_vchans; i++) { + struct owl_dma_vchan *vchan = &od->vchans[i]; + + vchan->vc.desc_free = owl_dma_desc_free; + vchan_init(&vchan->vc, &od->dma); + } + + /* Create a pool of consistent memory blocks for hardware descriptors */ + od->lli_pool = dma_pool_create(dev_name(od->dma.dev), od->dma.dev, + sizeof(struct owl_dma_lli), + __alignof__(struct owl_dma_lli), + 0); + if (!od->lli_pool) { + dev_err(&pdev->dev, "unable to allocate DMA descriptor pool\n"); + return -ENOMEM; + } + + clk_prepare_enable(od->clk); + + ret = dma_async_device_register(&od->dma); + if (ret) { + dev_err(&pdev->dev, "failed to register DMA engine device\n"); + goto err_pool_free; + } + + return 0; + +err_pool_free: + clk_disable_unprepare(od->clk); + dma_pool_destroy(od->lli_pool); + + return ret; +} + +static int owl_dma_remove(struct platform_device *pdev) +{ + struct owl_dma *od = platform_get_drvdata(pdev); + + dma_async_device_unregister(&od->dma); + + /* Mask all interrupts for this execution environment */ + dma_writel(od, OWL_DMA_IRQ_EN0, 0x0); + + /* Make sure we won't have any further interrupts */ + devm_free_irq(od->dma.dev, od->irq, od); + + owl_dma_free(od); + + clk_disable_unprepare(od->clk); + + return 0; +} + +static const struct of_device_id owl_dma_match[] = { + { .compatible = "actions,s900-dma", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, owl_dma_match); + +static struct platform_driver owl_dma_driver = { + .probe = owl_dma_probe, + .remove = owl_dma_remove, + .driver = { + .name = "dma-owl", + .of_match_table = of_match_ptr(owl_dma_match), + }, +}; + +static int owl_dma_init(void) +{ + return platform_driver_register(&owl_dma_driver); +} +subsys_initcall(owl_dma_init); + +static void __exit owl_dma_exit(void) +{ + platform_driver_unregister(&owl_dma_driver); +} +module_exit(owl_dma_exit); + +MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>"); +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>"); +MODULE_DESCRIPTION("Actions Semi Owl SoCs DMA driver"); +MODULE_LICENSE("GPL"); |