/* * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved. * * Refer to drivers/dma/imx-sdma.c * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "dmaengine.h" /* * NOTE: The term "PIO" throughout the mxs-dma implementation means * PIO mode of mxs apbh-dma and apbx-dma. With this working mode, * dma can program the controller registers of peripheral devices. */ #define dma_is_apbh(mxs_dma) ((mxs_dma)->type == MXS_DMA_APBH) #define apbh_is_old(mxs_dma) ((mxs_dma)->dev_id == IMX23_DMA) #define HW_APBHX_CTRL0 0x000 #define BM_APBH_CTRL0_APB_BURST8_EN (1 << 29) #define BM_APBH_CTRL0_APB_BURST_EN (1 << 28) #define BP_APBH_CTRL0_RESET_CHANNEL 16 #define HW_APBHX_CTRL1 0x010 #define HW_APBHX_CTRL2 0x020 #define HW_APBHX_CHANNEL_CTRL 0x030 #define BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL 16 /* * The offset of NXTCMDAR register is different per both dma type and version, * while stride for each channel is all the same 0x70. */ #define HW_APBHX_CHn_NXTCMDAR(d, n) \ (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x050 : 0x110) + (n) * 0x70) #define HW_APBHX_CHn_SEMA(d, n) \ (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x080 : 0x140) + (n) * 0x70) #define HW_APBHX_CHn_BAR(d, n) \ (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x070 : 0x130) + (n) * 0x70) #define HW_APBX_CHn_DEBUG1(d, n) (0x150 + (n) * 0x70) /* * ccw bits definitions * * COMMAND: 0..1 (2) * CHAIN: 2 (1) * IRQ: 3 (1) * NAND_LOCK: 4 (1) - not implemented * NAND_WAIT4READY: 5 (1) - not implemented * DEC_SEM: 6 (1) * WAIT4END: 7 (1) * HALT_ON_TERMINATE: 8 (1) * TERMINATE_FLUSH: 9 (1) * RESERVED: 10..11 (2) * PIO_NUM: 12..15 (4) */ #define BP_CCW_COMMAND 0 #define BM_CCW_COMMAND (3 << 0) #define CCW_CHAIN (1 << 2) #define CCW_IRQ (1 << 3) #define CCW_DEC_SEM (1 << 6) #define CCW_WAIT4END (1 << 7) #define CCW_HALT_ON_TERM (1 << 8) #define CCW_TERM_FLUSH (1 << 9) #define BP_CCW_PIO_NUM 12 #define BM_CCW_PIO_NUM (0xf << 12) #define BF_CCW(value, field) (((value) << BP_CCW_##field) & BM_CCW_##field) #define MXS_DMA_CMD_NO_XFER 0 #define MXS_DMA_CMD_WRITE 1 #define MXS_DMA_CMD_READ 2 #define MXS_DMA_CMD_DMA_SENSE 3 /* not implemented */ struct mxs_dma_ccw { u32 next; u16 bits; u16 xfer_bytes; #define MAX_XFER_BYTES 0xff00 u32 bufaddr; #define MXS_PIO_WORDS 16 u32 pio_words[MXS_PIO_WORDS]; }; #define CCW_BLOCK_SIZE (4 * PAGE_SIZE) #define NUM_CCW (int)(CCW_BLOCK_SIZE / sizeof(struct mxs_dma_ccw)) struct mxs_dma_chan { struct mxs_dma_engine *mxs_dma; struct dma_chan chan; struct dma_async_tx_descriptor desc; struct tasklet_struct tasklet; unsigned int chan_irq; struct mxs_dma_ccw *ccw; dma_addr_t ccw_phys; int desc_count; enum dma_status status; unsigned int flags; bool reset; #define MXS_DMA_SG_LOOP (1 << 0) #define MXS_DMA_USE_SEMAPHORE (1 << 1) }; #define MXS_DMA_CHANNELS 16 #define MXS_DMA_CHANNELS_MASK 0xffff enum mxs_dma_devtype { MXS_DMA_APBH, MXS_DMA_APBX, }; enum mxs_dma_id { IMX23_DMA, IMX28_DMA, }; struct mxs_dma_engine { enum mxs_dma_id dev_id; enum mxs_dma_devtype type; void __iomem *base; struct clk *clk; struct dma_device dma_device; struct device_dma_parameters dma_parms; struct mxs_dma_chan mxs_chans[MXS_DMA_CHANNELS]; struct platform_device *pdev; unsigned int nr_channels; }; struct mxs_dma_type { enum mxs_dma_id id; enum mxs_dma_devtype type; }; static struct mxs_dma_type mxs_dma_types[] = { { .id = IMX23_DMA, .type = MXS_DMA_APBH, }, { .id = IMX23_DMA, .type = MXS_DMA_APBX, }, { .id = IMX28_DMA, .type = MXS_DMA_APBH, }, { .id = IMX28_DMA, .type = MXS_DMA_APBX, } }; static const struct platform_device_id mxs_dma_ids[] = { { .name = "imx23-dma-apbh", .driver_data = (kernel_ulong_t) &mxs_dma_types[0], }, { .name = "imx23-dma-apbx", .driver_data = (kernel_ulong_t) &mxs_dma_types[1], }, { .name = "imx28-dma-apbh", .driver_data = (kernel_ulong_t) &mxs_dma_types[2], }, { .name = "imx28-dma-apbx", .driver_data = (kernel_ulong_t) &mxs_dma_types[3], }, { /* end of list */ } }; static const struct of_device_id mxs_dma_dt_ids[] = { { .compatible = "fsl,imx23-dma-apbh", .data = &mxs_dma_ids[0], }, { .compatible = "fsl,imx23-dma-apbx", .data = &mxs_dma_ids[1], }, { .compatible = "fsl,imx28-dma-apbh", .data = &mxs_dma_ids[2], }, { .compatible = "fsl,imx28-dma-apbx", .data = &mxs_dma_ids[3], }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, mxs_dma_dt_ids); static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan) { return container_of(chan, struct mxs_dma_chan, chan); } static void mxs_dma_reset_chan(struct dma_chan *chan) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; int chan_id = mxs_chan->chan.chan_id; /* * mxs dma channel resets can cause a channel stall. To recover from a * channel stall, we have to reset the whole DMA engine. To avoid this, * we use cyclic DMA with semaphores, that are enhanced in * mxs_dma_int_handler. To reset the channel, we can simply stop writing * into the semaphore counter. */ if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE && mxs_chan->flags & MXS_DMA_SG_LOOP) { mxs_chan->reset = true; } else if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) { writel(1 << (chan_id + BP_APBH_CTRL0_RESET_CHANNEL), mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); } else { unsigned long elapsed = 0; const unsigned long max_wait = 50000; /* 50ms */ void __iomem *reg_dbg1 = mxs_dma->base + HW_APBX_CHn_DEBUG1(mxs_dma, chan_id); /* * On i.MX28 APBX, the DMA channel can stop working if we reset * the channel while it is in READ_FLUSH (0x08) state. * We wait here until we leave the state. Then we trigger the * reset. Waiting a maximum of 50ms, the kernel shouldn't crash * because of this. */ while ((readl(reg_dbg1) & 0xf) == 0x8 && elapsed < max_wait) { udelay(100); elapsed += 100; } if (elapsed >= max_wait) dev_err(&mxs_chan->mxs_dma->pdev->dev, "Failed waiting for the DMA channel %d to leave state READ_FLUSH, trying to reset channel in READ_FLUSH state now\n", chan_id); writel(1 << (chan_id + BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL), mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET); } mxs_chan->status = DMA_COMPLETE; } static void mxs_dma_enable_chan(struct dma_chan *chan) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; int chan_id = mxs_chan->chan.chan_id; /* set cmd_addr up */ writel(mxs_chan->ccw_phys, mxs_dma->base + HW_APBHX_CHn_NXTCMDAR(mxs_dma, chan_id)); /* write 1 to SEMA to kick off the channel */ if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE && mxs_chan->flags & MXS_DMA_SG_LOOP) { /* A cyclic DMA consists of at least 2 segments, so initialize * the semaphore with 2 so we have enough time to add 1 to the * semaphore if we need to */ writel(2, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id)); } else { writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id)); } mxs_chan->reset = false; } static void mxs_dma_disable_chan(struct dma_chan *chan) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); mxs_chan->status = DMA_COMPLETE; } static int mxs_dma_pause_chan(struct dma_chan *chan) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; int chan_id = mxs_chan->chan.chan_id; /* freeze the channel */ if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) writel(1 << chan_id, mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); else writel(1 << chan_id, mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET); mxs_chan->status = DMA_PAUSED; return 0; } static int mxs_dma_resume_chan(struct dma_chan *chan) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; int chan_id = mxs_chan->chan.chan_id; /* unfreeze the channel */ if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) writel(1 << chan_id, mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_CLR); else writel(1 << chan_id, mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_CLR); mxs_chan->status = DMA_IN_PROGRESS; return 0; } static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx) { return dma_cookie_assign(tx); } static void mxs_dma_tasklet(unsigned long data) { struct mxs_dma_chan *mxs_chan = (struct mxs_dma_chan *) data; dmaengine_desc_get_callback_invoke(&mxs_chan->desc, NULL); } static int mxs_dma_irq_to_chan(struct mxs_dma_engine *mxs_dma, int irq) { int i; for (i = 0; i != mxs_dma->nr_channels; ++i) if (mxs_dma->mxs_chans[i].chan_irq == irq) return i; return -EINVAL; } static irqreturn_t mxs_dma_int_handler(int irq, void *dev_id) { struct mxs_dma_engine *mxs_dma = dev_id; struct mxs_dma_chan *mxs_chan; u32 completed; u32 err; int chan = mxs_dma_irq_to_chan(mxs_dma, irq); if (chan < 0) return IRQ_NONE; /* completion status */ completed = readl(mxs_dma->base + HW_APBHX_CTRL1); completed = (completed >> chan) & 0x1; /* Clear interrupt */ writel((1 << chan), mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR); /* error status */ err = readl(mxs_dma->base + HW_APBHX_CTRL2); err &= (1 << (MXS_DMA_CHANNELS + chan)) | (1 << chan); /* * error status bit is in the upper 16 bits, error irq bit in the lower * 16 bits. We transform it into a simpler error code: * err: 0x00 = no error, 0x01 = TERMINATION, 0x02 = BUS_ERROR */ err = (err >> (MXS_DMA_CHANNELS + chan)) + (err >> chan); /* Clear error irq */ writel((1 << chan), mxs_dma->base + HW_APBHX_CTRL2 + STMP_OFFSET_REG_CLR); /* * When both completion and error of termination bits set at the * same time, we do not take it as an error. IOW, it only becomes * an error we need to handle here in case of either it's a bus * error or a termination error with no completion. 0x01 is termination * error, so we can subtract err & completed to get the real error case. */ err -= err & completed; mxs_chan = &mxs_dma->mxs_chans[chan]; if (err) { dev_dbg(mxs_dma->dma_device.dev, "%s: error in channel %d\n", __func__, chan); mxs_chan->status = DMA_ERROR; mxs_dma_reset_chan(&mxs_chan->chan); } else if (mxs_chan->status != DMA_COMPLETE) { if (mxs_chan->flags & MXS_DMA_SG_LOOP) { mxs_chan->status = DMA_IN_PROGRESS; if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE) writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan)); } else { mxs_chan->status = DMA_COMPLETE; } } if (mxs_chan->status == DMA_COMPLETE) { if (mxs_chan->reset) return IRQ_HANDLED; dma_cookie_complete(&mxs_chan->desc); } /* schedule tasklet on this channel */ tasklet_schedule(&mxs_chan->tasklet); return IRQ_HANDLED; } static int mxs_dma_alloc_chan_resources(struct dma_chan *chan) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; int ret; mxs_chan->ccw = dma_zalloc_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE, &mxs_chan->ccw_phys, GFP_KERNEL); if (!mxs_chan->ccw) { ret = -ENOMEM; goto err_alloc; } ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler, 0, "mxs-dma", mxs_dma); if (ret) goto err_irq; ret = clk_prepare_enable(mxs_dma->clk); if (ret) goto err_clk; mxs_dma_reset_chan(chan); dma_async_tx_descriptor_init(&mxs_chan->desc, chan); mxs_chan->desc.tx_submit = mxs_dma_tx_submit; /* the descriptor is ready */ async_tx_ack(&mxs_chan->desc); return 0; err_clk: free_irq(mxs_chan->chan_irq, mxs_dma); err_irq: dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE, mxs_chan->ccw, mxs_chan->ccw_phys); err_alloc: return ret; } static void mxs_dma_free_chan_resources(struct dma_chan *chan) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; mxs_dma_disable_chan(chan); free_irq(mxs_chan->chan_irq, mxs_dma); dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE, mxs_chan->ccw, mxs_chan->ccw_phys); clk_disable_unprepare(mxs_dma->clk); } /* * How to use the flags for ->device_prep_slave_sg() : * [1] If there is only one DMA command in the DMA chain, the code should be: * ...... * ->device_prep_slave_sg(DMA_CTRL_ACK); * ...... * [2] If there are two DMA commands in the DMA chain, the code should be * ...... * ->device_prep_slave_sg(0); * ...... * ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); * ...... * [3] If there are more than two DMA commands in the DMA chain, the code * should be: * ...... * ->device_prep_slave_sg(0); // First * ...... * ->device_prep_slave_sg(DMA_PREP_INTERRUPT [| DMA_CTRL_ACK]); * ...... * ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); // Last * ...... */ static struct dma_async_tx_descriptor *mxs_dma_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 mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; struct mxs_dma_ccw *ccw; struct scatterlist *sg; u32 i, j; u32 *pio; bool append = flags & DMA_PREP_INTERRUPT; int idx = append ? mxs_chan->desc_count : 0; if (mxs_chan->status == DMA_IN_PROGRESS && !append) return NULL; if (sg_len + (append ? idx : 0) > NUM_CCW) { dev_err(mxs_dma->dma_device.dev, "maximum number of sg exceeded: %d > %d\n", sg_len, NUM_CCW); goto err_out; } mxs_chan->status = DMA_IN_PROGRESS; mxs_chan->flags = 0; /* * If the sg is prepared with append flag set, the sg * will be appended to the last prepared sg. */ if (append) { BUG_ON(idx < 1); ccw = &mxs_chan->ccw[idx - 1]; ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx; ccw->bits |= CCW_CHAIN; ccw->bits &= ~CCW_IRQ; ccw->bits &= ~CCW_DEC_SEM; } else { idx = 0; } if (direction == DMA_TRANS_NONE) { ccw = &mxs_chan->ccw[idx++]; pio = (u32 *) sgl; for (j = 0; j < sg_len;) ccw->pio_words[j++] = *pio++; ccw->bits = 0; ccw->bits |= CCW_IRQ; ccw->bits |= CCW_DEC_SEM; if (flags & DMA_CTRL_ACK) ccw->bits |= CCW_WAIT4END; ccw->bits |= CCW_HALT_ON_TERM; ccw->bits |= CCW_TERM_FLUSH; ccw->bits |= BF_CCW(sg_len, PIO_NUM); ccw->bits |= BF_CCW(MXS_DMA_CMD_NO_XFER, COMMAND); } else { for_each_sg(sgl, sg, sg_len, i) { if (sg_dma_len(sg) > MAX_XFER_BYTES) { dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n", sg_dma_len(sg), MAX_XFER_BYTES); goto err_out; } ccw = &mxs_chan->ccw[idx++]; ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx; ccw->bufaddr = sg->dma_address; ccw->xfer_bytes = sg_dma_len(sg); ccw->bits = 0; ccw->bits |= CCW_CHAIN; ccw->bits |= CCW_HALT_ON_TERM; ccw->bits |= CCW_TERM_FLUSH; ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ? MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND); if (i + 1 == sg_len) { ccw->bits &= ~CCW_CHAIN; ccw->bits |= CCW_IRQ; ccw->bits |= CCW_DEC_SEM; if (flags & DMA_CTRL_ACK) ccw->bits |= CCW_WAIT4END; } } } mxs_chan->desc_count = idx; return &mxs_chan->desc; err_out: mxs_chan->status = DMA_ERROR; return NULL; } static struct dma_async_tx_descriptor *mxs_dma_prep_dma_cyclic( struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len, size_t period_len, enum dma_transfer_direction direction, unsigned long flags, void *context) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; u32 num_periods = buf_len / period_len; u32 i = 0, buf = 0; if (mxs_chan->status == DMA_IN_PROGRESS) return NULL; mxs_chan->status = DMA_IN_PROGRESS; mxs_chan->flags |= MXS_DMA_SG_LOOP; mxs_chan->flags |= MXS_DMA_USE_SEMAPHORE; if (num_periods > NUM_CCW) { dev_err(mxs_dma->dma_device.dev, "maximum number of sg exceeded: %d > %d\n", num_periods, NUM_CCW); goto err_out; } if (period_len > MAX_XFER_BYTES) { dev_err(mxs_dma->dma_device.dev, "maximum period size exceeded: %zu > %d\n", period_len, MAX_XFER_BYTES); goto err_out; } while (buf < buf_len) { struct mxs_dma_ccw *ccw = &mxs_chan->ccw[i]; if (i + 1 == num_periods) ccw->next = mxs_chan->ccw_phys; else ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * (i + 1); ccw->bufaddr = dma_addr; ccw->xfer_bytes = period_len; ccw->bits = 0; ccw->bits |= CCW_CHAIN; ccw->bits |= CCW_IRQ; ccw->bits |= CCW_HALT_ON_TERM; ccw->bits |= CCW_TERM_FLUSH; ccw->bits |= CCW_DEC_SEM; ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ? MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND); dma_addr += period_len; buf += period_len; i++; } mxs_chan->desc_count = i; return &mxs_chan->desc; err_out: mxs_chan->status = DMA_ERROR; return NULL; } static int mxs_dma_terminate_all(struct dma_chan *chan) { mxs_dma_reset_chan(chan); mxs_dma_disable_chan(chan); return 0; } static enum dma_status mxs_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; u32 residue = 0; if (mxs_chan->status == DMA_IN_PROGRESS && mxs_chan->flags & MXS_DMA_SG_LOOP) { struct mxs_dma_ccw *last_ccw; u32 bar; last_ccw = &mxs_chan->ccw[mxs_chan->desc_count - 1]; residue = last_ccw->xfer_bytes + last_ccw->bufaddr; bar = readl(mxs_dma->base + HW_APBHX_CHn_BAR(mxs_dma, chan->chan_id)); residue -= bar; } dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie, residue); return mxs_chan->status; } static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma) { int ret; ret = clk_prepare_enable(mxs_dma->clk); if (ret) return ret; ret = stmp_reset_block(mxs_dma->base); if (ret) goto err_out; /* enable apbh burst */ if (dma_is_apbh(mxs_dma)) { writel(BM_APBH_CTRL0_APB_BURST_EN, mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); writel(BM_APBH_CTRL0_APB_BURST8_EN, mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); } /* enable irq for all the channels */ writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS, mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_SET); err_out: clk_disable_unprepare(mxs_dma->clk); return ret; } struct mxs_dma_filter_param { struct device_node *of_node; unsigned int chan_id; }; static bool mxs_dma_filter_fn(struct dma_chan *chan, void *fn_param) { struct mxs_dma_filter_param *param = fn_param; struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; int chan_irq; if (mxs_dma->dma_device.dev->of_node != param->of_node) return false; if (chan->chan_id != param->chan_id) return false; chan_irq = platform_get_irq(mxs_dma->pdev, param->chan_id); if (chan_irq < 0) return false; mxs_chan->chan_irq = chan_irq; return true; } static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct mxs_dma_engine *mxs_dma = ofdma->of_dma_data; dma_cap_mask_t mask = mxs_dma->dma_device.cap_mask; struct mxs_dma_filter_param param; if (dma_spec->args_count != 1) return NULL; param.of_node = ofdma->of_node; param.chan_id = dma_spec->args[0]; if (param.chan_id >= mxs_dma->nr_channels) return NULL; return dma_request_channel(mask, mxs_dma_filter_fn, ¶m); } static int __init mxs_dma_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; const struct platform_device_id *id_entry; const struct of_device_id *of_id; const struct mxs_dma_type *dma_type; struct mxs_dma_engine *mxs_dma; struct resource *iores; int ret, i; mxs_dma = devm_kzalloc(&pdev->dev, sizeof(*mxs_dma), GFP_KERNEL); if (!mxs_dma) return -ENOMEM; ret = of_property_read_u32(np, "dma-channels", &mxs_dma->nr_channels); if (ret) { dev_err(&pdev->dev, "failed to read dma-channels\n"); return ret; } of_id = of_match_device(mxs_dma_dt_ids, &pdev->dev); if (of_id) id_entry = of_id->data; else id_entry = platform_get_device_id(pdev); dma_type = (struct mxs_dma_type *)id_entry->driver_data; mxs_dma->type = dma_type->type; mxs_dma->dev_id = dma_type->id; iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); mxs_dma->base = devm_ioremap_resource(&pdev->dev, iores); if (IS_ERR(mxs_dma->base)) return PTR_ERR(mxs_dma->base); mxs_dma->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(mxs_dma->clk)) return PTR_ERR(mxs_dma->clk); dma_cap_set(DMA_SLAVE, mxs_dma->dma_device.cap_mask); dma_cap_set(DMA_CYCLIC, mxs_dma->dma_device.cap_mask); INIT_LIST_HEAD(&mxs_dma->dma_device.channels); /* Initialize channel parameters */ for (i = 0; i < MXS_DMA_CHANNELS; i++) { struct mxs_dma_chan *mxs_chan = &mxs_dma->mxs_chans[i]; mxs_chan->mxs_dma = mxs_dma; mxs_chan->chan.device = &mxs_dma->dma_device; dma_cookie_init(&mxs_chan->chan); tasklet_init(&mxs_chan->tasklet, mxs_dma_tasklet, (unsigned long) mxs_chan); /* Add the channel to mxs_chan list */ list_add_tail(&mxs_chan->chan.device_node, &mxs_dma->dma_device.channels); } ret = mxs_dma_init(mxs_dma); if (ret) return ret; mxs_dma->pdev = pdev; mxs_dma->dma_device.dev = &pdev->dev; /* mxs_dma gets 65535 bytes maximum sg size */ mxs_dma->dma_device.dev->dma_parms = &mxs_dma->dma_parms; dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES); mxs_dma->dma_device.device_alloc_chan_resources = mxs_dma_alloc_chan_resources; mxs_dma->dma_device.device_free_chan_resources = mxs_dma_free_chan_resources; mxs_dma->dma_device.device_tx_status = mxs_dma_tx_status; mxs_dma->dma_device.device_prep_slave_sg = mxs_dma_prep_slave_sg; mxs_dma->dma_device.device_prep_dma_cyclic = mxs_dma_prep_dma_cyclic; mxs_dma->dma_device.device_pause = mxs_dma_pause_chan; mxs_dma->dma_device.device_resume = mxs_dma_resume_chan; mxs_dma->dma_device.device_terminate_all = mxs_dma_terminate_all; mxs_dma->dma_device.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); mxs_dma->dma_device.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); mxs_dma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); mxs_dma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; mxs_dma->dma_device.device_issue_pending = mxs_dma_enable_chan; ret = dma_async_device_register(&mxs_dma->dma_device); if (ret) { dev_err(mxs_dma->dma_device.dev, "unable to register\n"); return ret; } ret = of_dma_controller_register(np, mxs_dma_xlate, mxs_dma); if (ret) { dev_err(mxs_dma->dma_device.dev, "failed to register controller\n"); dma_async_device_unregister(&mxs_dma->dma_device); } dev_info(mxs_dma->dma_device.dev, "initialized\n"); return 0; } static struct platform_driver mxs_dma_driver = { .driver = { .name = "mxs-dma", .of_match_table = mxs_dma_dt_ids, }, .id_table = mxs_dma_ids, }; static int __init mxs_dma_module_init(void) { return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe); } subsys_initcall(mxs_dma_module_init);