diff options
Diffstat (limited to 'kernel/drivers/dma/mxs-dma.c')
| -rw-r--r-- | kernel/drivers/dma/mxs-dma.c | 887 |
1 files changed, 887 insertions, 0 deletions
diff --git a/kernel/drivers/dma/mxs-dma.c b/kernel/drivers/dma/mxs-dma.c new file mode 100644 index 000000000..829ec686d --- /dev/null +++ b/kernel/drivers/dma/mxs-dma.c @@ -0,0 +1,887 @@ +/* + * 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 <linux/init.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/clk.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/semaphore.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/dmaengine.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/stmp_device.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_dma.h> +#include <linux/list.h> + +#include <asm/irq.h> + +#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 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; + + if (mxs_chan->desc.callback) + mxs_chan->desc.callback(mxs_chan->desc.callback_param); +} + +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; + } + + if (mxs_chan->chan_irq != NO_IRQ) { + 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) +{ + 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: %d > %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); |