summaryrefslogtreecommitdiffstats
path: root/drivers/dma/mxs-dma.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/dma/mxs-dma.c842
1 files changed, 842 insertions, 0 deletions
diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
new file mode 100644
index 0000000000..cfb9962417
--- /dev/null
+++ b/drivers/dma/mxs-dma.c
@@ -0,0 +1,842 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+//
+// Refer to drivers/dma/imx-sdma.c
+
+#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_dma.h>
+#include <linux/list.h>
+#include <linux/dma/mxs-dma.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_WAIT4RDY (1 << 5)
+#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 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 of_device_id mxs_dma_dt_ids[] = {
+ { .compatible = "fsl,imx23-dma-apbh", .data = &mxs_dma_types[0], },
+ { .compatible = "fsl,imx23-dma-apbx", .data = &mxs_dma_types[1], },
+ { .compatible = "fsl,imx28-dma-apbh", .data = &mxs_dma_types[2], },
+ { .compatible = "fsl,imx28-dma-apbx", .data = &mxs_dma_types[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(struct tasklet_struct *t)
+{
+ struct mxs_dma_chan *mxs_chan = from_tasklet(mxs_chan, t, tasklet);
+
+ 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_alloc_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_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_CTRL_ACK]);
+ * ......
+ * ->device_prep_slave_sg(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;
+ int idx = 0;
+
+ if (mxs_chan->status == DMA_IN_PROGRESS)
+ idx = mxs_chan->desc_count;
+
+ if (sg_len + idx > 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 (idx) {
+ 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 & MXS_DMA_CTRL_WAIT4END)
+ 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);
+ if (flags & MXS_DMA_CTRL_WAIT4RDY)
+ ccw->bits |= CCW_WAIT4RDY;
+ } 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 & MXS_DMA_CTRL_WAIT4END)
+ 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: %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 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 {
+ 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 (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.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, &param,
+ ofdma->of_node);
+}
+
+static int mxs_dma_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ const struct mxs_dma_type *dma_type;
+ struct mxs_dma_engine *mxs_dma;
+ 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;
+ }
+
+ dma_type = (struct mxs_dma_type *)of_device_get_match_data(&pdev->dev);
+ mxs_dma->type = dma_type->type;
+ mxs_dma->dev_id = dma_type->id;
+
+ mxs_dma->base = devm_platform_ioremap_resource(pdev, 0);
+ 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_setup(&mxs_chan->tasklet, mxs_dma_tasklet);
+
+
+ /* 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 */
+ 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 = dmaenginem_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");
+ }
+
+ 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,
+ },
+ .probe = mxs_dma_probe,
+};
+
+builtin_platform_driver(mxs_dma_driver);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-05 00:04:21 +0000