[PATCH 2/4] dmaengine: mtk_uart_dma: add Mediatek uart DMA support

Long Cheng
2017-02-16T11:07:29Z

In DMA engine framework, add 8250 mtk dma to support it.

Signed-off-by: Long Cheng <long.cheng-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
drivers/dma/Kconfig | 9 +
drivers/dma/Makefile | 1 +
drivers/dma/mtk_uart_dma.c | 955 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 965 insertions(+)
create mode 100644 drivers/dma/mtk_uart_dma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 263495d..d76dc96 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -128,6 +128,15 @@ config DMA_JZ4780
If you have a board based on such a SoC and wish to use DMA for
devices which can use the DMA controller, say Y or M here.

+config DMA_MTK_UART
+ tristate "MediaTek SoCs APDMA support for UART"
+ depends on OF
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ Support for the UART DMA engine found on MediaTek MTK SoCs.
+ This DMA engine just only if used when 8250 mtk uart is enabled.
+
config DMA_OMAP
tristate "OMAP DMA support"
depends on ARCH_OMAP || COMPILE_TEST
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index a4fa336..5f0404a 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_COH901318) += coh901318.o coh901318_lli.o
obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
obj-$(CONFIG_DMA_JZ4780) += dma-jz4780.o
+obj-$(CONFIG_DMA_MTK_UART) += mtk_uart_dma.o
obj-$(CONFIG_DMA_OMAP) += omap-dma.o
obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o
obj-$(CONFIG_DMA_SUN4I) += sun4i-dma.o
diff --git a/drivers/dma/mtk_uart_dma.c b/drivers/dma/mtk_uart_dma.c
new file mode 100644
index 0000000..b884079
--- /dev/null
+++ b/drivers/dma/mtk_uart_dma.c
@@ -0,0 +1,955 @@
+/*
+ * MTK DMAengine support
+ *
+ * Copyright (c) 2016 MediaTek Inc.
+ * Author: Long Cheng (Long) <long.cheng-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
+ *
+ * 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/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "virt-dma.h"
+
+#define MTK_SDMA_REQUESTS 127
+#define MTK_SDMA_CHANNELS 8
+#define MTK_POLLING_CNT 10000
+
+#define DRV_NAME "mtk-uart-dma"
+
+/*---------------------------------------------------------------------------*/
+#define VFF_INT_FLAG_CLR_B 0
+/*VFF_INT_EN*/
+#define VFF_RX_INT_EN0_B BIT(0)
+#define VFF_RX_INT_EN1_B BIT(1)
+#define VFF_TX_INT_EN_B BIT(0)
+#define VFF_INT_EN_CLR_B 0
+/*VFF_RST*/
+#define VFF_WARM_RST_B BIT(0)
+/*VFF_EN*/
+#define VFF_EN_B BIT(0)
+/*VFF_STOP*/
+#define VFF_STOP_B BIT(0)
+#define VFF_STOP_CLR_B 0
+/*VFF_FLUSH*/
+#define VFF_FLUSH_B BIT(0)
+#define VFF_FLUSH_CLR_B 0
+
+#define VFF_TX_THRE(n) ((n)*7/8)
+#define VFF_RX_THRE(n) ((n)*3/4)
+
+/*---------------------------------------------------------------------------*/
+
+struct mtk_dmadev {
+ struct dma_device ddev;
+ spinlock_t lock;
+ struct tasklet_struct task;
+ struct list_head pending;
+ void __iomem *base;
+ int irq;
+ struct clk *clk;
+ unsigned int dma_requests;
+ uint32_t irq_enable_mask;
+ struct mtk_chan *lch_map[MTK_SDMA_CHANNELS];
+};
+
+struct mtk_chan {
+ struct virt_dma_chan vc;
+ struct list_head node;
+ void __iomem *channel_base;
+ uint32_t ccr;
+
+ struct dma_slave_config cfg;
+ unsigned int dma_sig;
+ bool paused;
+ bool requested;
+
+ int dma_ch;
+ struct mtk_desc *desc;
+ unsigned int sgidx;
+
+ size_t trig;
+ size_t remain_size;
+ size_t rx_ptr;
+
+ /*sync*/
+ struct completion done; /* dma transfer done */
+ spinlock_t lock;
+ atomic_t loopcnt;
+ atomic_t entry; /* entry count */
+};
+
+struct mtk_sg {
+ dma_addr_t addr;
+ uint32_t en; /* number of elements (24-bit) */
+ uint32_t fn; /* number of frames (16-bit) */
+};
+
+struct mtk_desc {
+ struct virt_dma_desc vd;
+ enum dma_transfer_direction dir;
+ dma_addr_t dev_addr;
+
+ unsigned int sglen;
+ struct mtk_sg sg[0];
+};
+
+enum {
+ VFF_INT_FLAG = 0x00,
+ VFF_INT_EN = 0x04,
+ VFF_EN = 0x08,
+ VFF_RST = 0x0c,
+ VFF_STOP = 0x10,
+ VFF_FLUSH = 0x14,
+ VFF_ADDR = 0x1c,
+ VFF_LEN = 0x24,
+ VFF_THRE = 0x28,
+ VFF_WPT = 0x2c,
+ VFF_RPT = 0x30,
+ VFF_VALID_SIZE = 0x3c,
+ VFF_LEFT_SIZE = 0x40,
+ VFF_DEBUG_STATUS = 0x50,
+};
+
+static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param);
+static struct of_dma_filter_info mtk_dma_info = {
+ .filter_fn = mtk_dma_filter_fn,
+};
+
+static inline struct mtk_dmadev *to_mtk_dma_dev(struct dma_device *d)
+{
+ return container_of(d, struct mtk_dmadev, ddev);
+}
+
+static inline struct mtk_chan *to_mtk_dma_chan(struct dma_chan *c)
+{
+ return container_of(c, struct mtk_chan, vc.chan);
+}
+
+static inline struct mtk_desc *
+to_mtk_dma_desc(struct dma_async_tx_descriptor *t)
+{
+ return container_of(t, struct mtk_desc, vd.tx);
+}
+
+static void
+mtk_dma_chan_write(struct mtk_chan *c, unsigned int reg, unsigned int val)
+{
+ writel(val, c->channel_base + reg);
+}
+
+static unsigned int mtk_dma_chan_read(struct mtk_chan *c, unsigned int reg)
+{
+ return readl(c->channel_base + reg);
+}
+
+static void mtk_dma_desc_free(struct virt_dma_desc *vd)
+{
+ struct dma_chan *chan = vd->tx.chan;
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+
+ spin_lock(&c->lock);
+ if (c->desc != NULL) {
+ kfree(c->desc);
+ c->desc = NULL;
+
+ if (c->cfg.direction == DMA_DEV_TO_MEM)
+ atomic_dec(&c->entry);
+ }
+ spin_unlock(&c->lock);
+}
+
+static int mtk_dma_clk_enable(struct mtk_dmadev *mtkd)
+{
+ int rc;
+
+ rc = clk_prepare_enable(mtkd->clk);
+ if (rc)
+ dev_err(mtkd->ddev.dev, "Couldn't enable the clock\n");
+
+ return rc;
+}
+
+static void mtk_dma_clk_disable(struct mtk_dmadev *mtkd)
+{
+ clk_disable_unprepare(mtkd->clk);
+}
+
+static void
+mtk_dma_remove_virt_list(dma_cookie_t cookie, struct virt_dma_chan *vc)
+{
+ struct virt_dma_desc *vd;
+
+ if (!list_empty(&vc->desc_issued)) {
+ list_for_each_entry(vd, &vc->desc_issued, node) {
+ if (cookie == vd->tx.cookie) {
+ INIT_LIST_HEAD(&vc->desc_issued);
+ break;
+ }
+ }
+ }
+}
+
+static void mtk_dma_tx_flush(struct dma_chan *chan, int timeout)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+
+ if (mtk_dma_chan_read(c, VFF_FLUSH) == 0) {
+ mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_B);
+ if (atomic_dec_and_test(&c->loopcnt))
+ complete(&c->done);
+ }
+}
+
+static int mtk_dma_tx_write(struct dma_chan *chan)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct timespec a, b;
+ int txcount = c->remain_size;
+ unsigned int tx_size = c->cfg.dst_addr_width*1024;
+ unsigned int len, left;
+ unsigned int wpt;
+ ktime_t begin, end;
+
+ if (atomic_inc_and_test(&c->entry) > 1) {
+ if (vchan_issue_pending(&c->vc) && !c->desc) {
+ spin_lock(&mtkd->lock);
+ list_add_tail(&c->node, &mtkd->pending);
+ spin_unlock(&mtkd->lock);
+ tasklet_schedule(&mtkd->task);
+ }
+ } else {
+ while (mtk_dma_chan_read(c, VFF_LEFT_SIZE) >= c->trig) {
+ left = tx_size - mtk_dma_chan_read(c, VFF_VALID_SIZE);
+ left = (left > 16) ? (left - 16) : (0);
+ len = left < c->remain_size ? left : c->remain_size;
+
+ begin = ktime_get();
+ a = ktime_to_timespec(begin);
+ while (len--) {
+ /*
+ * DMA limitation.
+ * Workaround: Polling flush bit to zero,
+ * set 1s timeout
+ */
+ while (mtk_dma_chan_read(c, VFF_FLUSH)) {
+ end = ktime_get();
+ b = ktime_to_timespec(end);
+ if ((b.tv_sec - a.tv_sec) > 1 ||
+ ((b.tv_sec - a.tv_sec) == 1 &&
+ b.tv_nsec > a.tv_nsec)) {
+ dev_info(chan->device->dev,
+ "[UART] Polling flush timeout\n");
+ return 0;
+ }
+ }
+
+ wpt = mtk_dma_chan_read(c, VFF_WPT);
+
+ if ((wpt & 0x0000ffffl) ==
+ (mtk_dma_chan_read(c, VFF_LEN) - 1))
+ mtk_dma_chan_write(c, VFF_WPT,
+ (~wpt)&0x10000);
+ else
+ mtk_dma_chan_write(c, VFF_WPT, wpt+1);
+ c->remain_size--;
+ }
+ if (c->remain_size == 0)
+ break;
+ }
+
+ if (txcount != c->remain_size) {
+ mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
+ mtk_dma_tx_flush(chan, 0);
+ }
+ }
+ atomic_dec(&c->entry);
+ return 0;
+}
+
+
+static void mtk_dma_start_tx(struct mtk_chan *c)
+{
+ if (mtk_dma_chan_read(c, VFF_LEFT_SIZE) == 0) {
+ dev_info(c->vc.chan.device->dev, "%s maybe need fix? %d @L %d\n",
+ __func__, mtk_dma_chan_read(c, VFF_LEFT_SIZE),
+ __LINE__);
+ mtk_dma_chan_write(c, VFF_INT_EN, VFF_TX_INT_EN_B);
+ } else {
+ reinit_completion(&c->done);
+ atomic_inc(&c->loopcnt);
+ atomic_inc(&c->loopcnt);
+ mtk_dma_tx_write(&c->vc.chan);
+ }
+ c->paused = false;
+}
+
+static void mtk_dma_get_dst_pos(struct mtk_chan *c)
+{
+ int count;
+ unsigned int rxptr, txptr, txreg, rxreg;
+ size_t rx_size;
+
+ rx_size = c->cfg.src_addr_width*1024;
+
+ rxreg = mtk_dma_chan_read(c, VFF_RPT);
+ txreg = mtk_dma_chan_read(c, VFF_WPT);
+ rxptr = rxreg & 0x0000ffffl;
+ txptr = txreg & 0x0000ffffl;
+ count = ((rxreg ^ txreg) & 0x00010000) ?
+ (txptr + rx_size - rxptr) : (txptr - rxptr);
+
+ c->remain_size = count;
+ c->rx_ptr = rxptr;
+
+ mtk_dma_chan_write(c, VFF_RPT, txreg);
+}
+
+static void mtk_dma_start_rx(struct mtk_chan *c)
+{
+ struct mtk_desc *d = c->desc;
+
+ if (mtk_dma_chan_read(c, VFF_VALID_SIZE) != 0 && c->desc != NULL) {
+ mtk_dma_get_dst_pos(c);
+ mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
+ vchan_cookie_complete(&d->vd);
+ }
+}
+
+static void mtk_dma_reset(struct mtk_chan *c)
+{
+ struct timespec a, b;
+ ktime_t begin, end;
+
+ mtk_dma_chan_write(c, VFF_ADDR, 0);
+ mtk_dma_chan_write(c, VFF_THRE, 0);
+ mtk_dma_chan_write(c, VFF_LEN, 0);
+ mtk_dma_chan_write(c, VFF_RST, VFF_WARM_RST_B);
+
+ begin = ktime_get();
+ a = ktime_to_timespec(begin);
+ while (mtk_dma_chan_read(c, VFF_EN)) {
+ end = ktime_get();
+ b = ktime_to_timespec(end);
+ if ((b.tv_sec - a.tv_sec) > 1 ||
+ ((b.tv_sec - a.tv_sec) == 1 &&
+ b.tv_nsec > a.tv_nsec)) {
+ dev_info(c->vc.chan.device->dev,
+ "[UART] Polling VFF EN timeout\n");
+ return;
+ }
+ }
+
+ if (c->cfg.direction == DMA_DEV_TO_MEM)
+ mtk_dma_chan_write(c, VFF_RPT, 0);
+ else if (c->cfg.direction == DMA_MEM_TO_DEV)
+ mtk_dma_chan_write(c, VFF_WPT, 0);
+}
+
+static void mtk_dma_stop(struct mtk_chan *c)
+{
+ int polling_cnt;
+
+ mtk_dma_chan_write(c, VFF_FLUSH, VFF_FLUSH_CLR_B);
+
+ polling_cnt = 0;
+ while (mtk_dma_chan_read(c, VFF_FLUSH)) {
+ polling_cnt++;
+ if (polling_cnt > MTK_POLLING_CNT) {
+ dev_info(c->vc.chan.device->dev, "mtk_uart_stop_dma: polling VFF_FLUSH fail VFF_DEBUG_STATUS=0x%x\n",
+ mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
+ break;
+ }
+ }
+
+ polling_cnt = 0;
+ /*set stop as 1 -> wait until en is 0 -> set stop as 0*/
+ mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_B);
+ while (mtk_dma_chan_read(c, VFF_EN)) {
+ polling_cnt++;
+ if (polling_cnt > MTK_POLLING_CNT) {
+ dev_info(c->vc.chan.device->dev, "mtk_uart_stop_dma: polling VFF_EN fail VFF_DEBUG_STATUS=0x%x\n",
+ mtk_dma_chan_read(c, VFF_DEBUG_STATUS));
+ break;
+ }
+ }
+ mtk_dma_chan_write(c, VFF_STOP, VFF_STOP_CLR_B);
+ mtk_dma_chan_write(c, VFF_INT_EN, VFF_INT_EN_CLR_B);
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_INT_FLAG_CLR_B);
+
+ c->paused = true;
+}
+
+/*
+ * This callback schedules all pending channels. We could be more
+ * clever here by postponing allocation of the real DMA channels to
+ * this point, and freeing them when our virtual channel becomes idle.
+ *
+ * We would then need to deal with 'all channels in-use'
+ */
+static void mtk_dma_sched(unsigned long data)
+{
+ struct mtk_dmadev *mtkd = (struct mtk_dmadev *)data;
+ struct mtk_chan *c;
+ struct virt_dma_desc *vd;
+ dma_cookie_t cookie;
+ LIST_HEAD(head);
+
+ spin_lock_irq(&mtkd->lock);
+ list_splice_tail_init(&mtkd->pending, &head);
+ spin_unlock_irq(&mtkd->lock);
+
+ while (!list_empty(&head)) {
+ c = list_first_entry(&head, struct mtk_chan, node);
+ cookie = c->vc.chan.cookie;
+
+ spin_lock_irq(&c->vc.lock);
+
+ if (c->cfg.direction == DMA_DEV_TO_MEM) {
+ list_del_init(&c->node);
+ mtk_dma_start_rx(c);
+ } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
+ vd = vchan_find_desc(&c->vc, cookie);
+
+ c->desc = to_mtk_dma_desc(&vd->tx);
+ list_del_init(&c->node);
+ mtk_dma_start_tx(c);
+ } else {
+ dev_warn(c->vc.chan.device->dev, "%s maybe error @Line%d\n",
+ __func__, __LINE__);
+ }
+ spin_unlock_irq(&c->vc.lock);
+ }
+}
+
+static int mtk_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ int ret;
+
+ ret = -EBUSY;
+
+ if (mtkd->lch_map[c->dma_ch] == NULL) {
+ c->channel_base = mtkd->base + 0x80 * c->dma_ch;
+ mtkd->lch_map[c->dma_ch] = c;
+ ret = 1;
+ }
+ c->requested = false;
+ mtk_dma_reset(c);
+
+ return ret;
+}
+
+static void mtk_dma_free_chan_resources(struct dma_chan *chan)
+{
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+
+ if (c->requested == true) {
+ c->requested = false;
+ free_irq(mtkd->irq + c->dma_ch, chan);
+ }
+
+ c->channel_base = NULL;
+ mtkd->lch_map[c->dma_ch] = NULL;
+ vchan_free_chan_resources(&c->vc);
+
+ dev_dbg(mtkd->ddev.dev, "freeing channel for %u\n", c->dma_sig);
+ c->dma_sig = 0;
+}
+
+static enum dma_status mtk_dma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie, struct dma_tx_state *txstate)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ enum dma_status ret;
+ unsigned long flags;
+
+ ret = dma_cookie_status(chan, cookie, txstate);
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+
+ if (ret == DMA_IN_PROGRESS) {
+ c->rx_ptr = mtk_dma_chan_read(c, VFF_RPT) & 0x0000ffffl;
+ txstate->residue = c->rx_ptr;
+ } else if (ret == DMA_COMPLETE && c->cfg.direction == DMA_DEV_TO_MEM) {
+ txstate->residue = c->remain_size;
+ } else {
+ txstate->residue = 0;
+ }
+
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+
+ return ret;
+}
+
+static size_t mtk_dma_desc_size(struct mtk_desc *d)
+{
+ struct mtk_sg *sg;
+ unsigned int i;
+ size_t size;
+
+ for (size = i = 0; i < d->sglen; i++) {
+ sg = &d->sg[i];
+ size += sg->en * sg->fn;
+ }
+ return size;
+}
+
+static struct dma_async_tx_descriptor *mtk_dma_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl, unsigned int sglen,
+ enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ enum dma_slave_buswidth dev_width;
+ struct scatterlist *sgent;
+ struct mtk_desc *d;
+ dma_addr_t dev_addr;
+ unsigned int i, j, en, frame_bytes;
+
+ en = frame_bytes = 1;
+
+ if (dir == DMA_DEV_TO_MEM) {
+ dev_addr = c->cfg.src_addr;
+ dev_width = c->cfg.src_addr_width;
+ } else if (dir == DMA_MEM_TO_DEV) {
+ dev_addr = c->cfg.dst_addr;
+ dev_width = c->cfg.dst_addr_width;
+ } else {
+ dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
+ return NULL;
+ }
+
+ /* Now allocate and setup the descriptor. */
+ d = kmalloc(sizeof(*d) + sglen * sizeof(d->sg[0]),
+ GFP_KERNEL | ___GFP_ZERO);
+ if (!d)
+ return NULL;
+
+ d->dir = dir;
+ d->dev_addr = dev_addr;
+
+ j = 0;
+ for_each_sg(sgl, sgent, sglen, i) {
+ d->sg[j].addr = sg_dma_address(sgent);
+ d->sg[j].en = en;
+ d->sg[j].fn = sg_dma_len(sgent) / frame_bytes;
+ j++;
+ }
+
+ d->sglen = j;
+
+ if (dir == DMA_MEM_TO_DEV)
+ c->remain_size = mtk_dma_desc_size(d);
+
+ return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
+}
+
+static void mtk_dma_issue_pending(struct dma_chan *chan)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct mtk_dmadev *mtkd;
+ struct virt_dma_desc *vd;
+ dma_cookie_t cookie;
+ unsigned long flags;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+
+ if (c->cfg.direction == DMA_DEV_TO_MEM) {
+ cookie = c->vc.chan.cookie;
+ mtkd = to_mtk_dma_dev(chan->device);
+ if (vchan_issue_pending(&c->vc) && !c->desc) {
+ vd = vchan_find_desc(&c->vc, cookie);
+ c->desc = to_mtk_dma_desc(&vd->tx);
+ if (atomic_read(&c->entry) > 0)
+ atomic_set(&c->entry, 0);
+ }
+ } else if (c->cfg.direction == DMA_MEM_TO_DEV) {
+ cookie = c->vc.chan.cookie;
+ if (vchan_issue_pending(&c->vc) && !c->desc) {
+ vd = vchan_find_desc(&c->vc, cookie);
+ c->desc = to_mtk_dma_desc(&vd->tx);
+ mtk_dma_start_tx(c);
+ }
+ }
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+}
+
+
+static irqreturn_t mtk_dma_rx_interrupt(int irq, void *dev_id)
+{
+ struct dma_chan *chan = (struct dma_chan *)dev_id;
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+
+ mtk_dma_chan_write(c, VFF_INT_FLAG, 0x03);
+
+ if (!(atomic_add_return(1, &c->entry) > 1))
+ mtk_dma_start_rx(c);
+
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mtk_dma_tx_interrupt(int irq, void *dev_id)
+{
+ struct dma_chan *chan = (struct dma_chan *)dev_id;
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_desc *d = c->desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+
+ if (c->remain_size != 0) {
+ /* maybe never can't enter*/
+ dev_warn(chan->device->dev, "%s errrrrr---remain[%d]-----%d--\n",
+ __func__, (int)c->remain_size, __LINE__);
+ spin_lock(&mtkd->lock);
+ list_add_tail(&c->node, &mtkd->pending);
+ spin_unlock(&mtkd->lock);
+ tasklet_schedule(&mtkd->task);
+ } else {
+ mtk_dma_remove_virt_list(d->vd.tx.cookie, &c->vc);
+ vchan_cookie_complete(&d->vd);
+ }
+
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_INT_FLAG_CLR_B);
+
+ if (atomic_dec_and_test(&c->loopcnt))
+ complete(&c->done);
+
+ return IRQ_HANDLED;
+
+}
+
+static int
+mtk_dma_slave_config(struct dma_chan *chan, struct dma_slave_config *cfg)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
+ int ret;
+
+ memcpy(&c->cfg, cfg, sizeof(c->cfg));
+
+ if (cfg->direction == DMA_DEV_TO_MEM) {
+ mtk_dma_chan_write(c, VFF_ADDR, cfg->src_addr);
+ mtk_dma_chan_write(c, VFF_LEN, cfg->src_addr_width*1024);
+ mtk_dma_chan_write(c, VFF_THRE,
+ VFF_RX_THRE(cfg->src_addr_width*1024));
+ mtk_dma_chan_write(c, VFF_INT_EN,
+ VFF_RX_INT_EN0_B | VFF_RX_INT_EN1_B);
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_INT_FLAG_CLR_B);
+ mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
+
+ if (c->requested == false) {
+ atomic_set(&c->entry, 0);
+ c->requested = true;
+ ret = request_irq(mtkd->irq + c->dma_ch,
+ mtk_dma_rx_interrupt,
+ IRQF_TRIGGER_NONE,
+ DRV_NAME, chan);
+ if (ret) {
+ dev_err(chan->device->dev, "Cannot request IRQ\n");
+ return IRQ_NONE;
+ }
+ }
+ } else if (cfg->direction == DMA_MEM_TO_DEV) {
+ mtk_dma_chan_write(c, VFF_ADDR, cfg->dst_addr);
+ mtk_dma_chan_write(c, VFF_LEN, cfg->dst_addr_width*1024);
+ mtk_dma_chan_write(c, VFF_THRE,
+ VFF_TX_THRE(cfg->dst_addr_width*1024));
+ mtk_dma_chan_write(c, VFF_INT_FLAG, VFF_INT_FLAG_CLR_B);
+ mtk_dma_chan_write(c, VFF_EN, VFF_EN_B);
+
+ if (c->requested == false) {
+ c->requested = true;
+ ret = request_irq(mtkd->irq + c->dma_ch,
+ mtk_dma_tx_interrupt,
+ IRQF_TRIGGER_NONE,
+ DRV_NAME, chan);
+ if (ret) {
+ dev_err(chan->device->dev, "Cannot request IRQ\n");
+ return IRQ_NONE;
+ }
+ }
+ }
+
+ if (mtk_dma_chan_read(c, VFF_EN) != VFF_EN_B) {
+ dev_err(chan->device->dev, "Start DMA fail\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int mtk_dma_terminate_all(struct dma_chan *chan)
+{
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(c->vc.chan.device);
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ if (atomic_read(&c->loopcnt) != 0)
+ wait_for_completion(&c->done);
+
+ spin_lock_irqsave(&c->vc.lock, flags);
+
+ /* Prevent this channel being scheduled */
+ spin_lock(&mtkd->lock);
+ list_del_init(&c->node);
+ spin_unlock(&mtkd->lock);
+
+ if (c->desc) {
+ mtk_dma_remove_virt_list(c->desc->vd.tx.cookie, &c->vc);
+ mtk_dma_desc_free(&c->desc->vd);
+ if (!c->paused)
+ mtk_dma_stop(c);
+ }
+
+ vchan_get_all_descriptors(&c->vc, &head);
+ spin_unlock_irqrestore(&c->vc.lock, flags);
+ vchan_dma_desc_free_list(&c->vc, &head);
+
+ return 0;
+}
+
+static int mtk_dma_pause(struct dma_chan *chan)
+{
+ /* Pause/Resume only allowed with cyclic mode */
+ return -EINVAL;
+}
+
+static int mtk_dma_resume(struct dma_chan *chan)
+{
+ /* Pause/Resume only allowed with cyclic mode */
+ return -EINVAL;
+}
+
+static int mtk_dma_chan_init(struct mtk_dmadev *mtkd)
+{
+ struct mtk_chan *c;
+
+ c = devm_kzalloc(mtkd->ddev.dev, sizeof(*c), GFP_KERNEL);
+ if (!c)
+ return -ENOMEM;
+
+ c->vc.desc_free = mtk_dma_desc_free;
+ vchan_init(&c->vc, &mtkd->ddev);
+ spin_lock_init(&c->lock);
+ INIT_LIST_HEAD(&c->node);
+
+ init_completion(&c->done);
+ atomic_set(&c->loopcnt, 0);
+ atomic_set(&c->entry, 0);
+
+ return 0;
+}
+
+static void mtk_dma_free(struct mtk_dmadev *mtkd)
+{
+ tasklet_kill(&mtkd->task);
+ while (!list_empty(&mtkd->ddev.channels)) {
+ struct mtk_chan *c = list_first_entry(&mtkd->ddev.channels,
+ struct mtk_chan, vc.chan.device_node);
+
+ list_del(&c->vc.chan.device_node);
+ tasklet_kill(&c->vc.task);
+ devm_kfree(mtkd->ddev.dev, c);
+ }
+}
+
+static const struct of_device_id mtk_uart_dma_match[] = {
+ { .compatible = "mediatek,mt6577-uart-dma", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mtk_uart_dma_match);
+
+static int mtk_dma_probe(struct platform_device *pdev)
+{
+ struct mtk_dmadev *mtkd;
+ struct resource *res;
+ int rc, i;
+
+ rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ if (rc)
+ return rc;
+
+ mtkd = devm_kzalloc(&pdev->dev, sizeof(*mtkd), GFP_KERNEL);
+ if (!mtkd)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+ mtkd->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mtkd->base))
+ return PTR_ERR(mtkd->base);
+
+ mtkd->irq = platform_get_irq(pdev, 0);
+ if (mtkd->irq < 0) {
+ dev_err(&pdev->dev, "Cannot claim IRQ\n");
+ return mtkd->irq;
+ }
+
+ mtkd->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(mtkd->clk)) {
+ dev_err(&pdev->dev, "No clock specified\n");
+ return PTR_ERR(mtkd->clk);
+ }
+
+ dma_cap_set(DMA_SLAVE, mtkd->ddev.cap_mask);
+ mtkd->ddev.device_alloc_chan_resources = mtk_dma_alloc_chan_resources;
+ mtkd->ddev.device_free_chan_resources = mtk_dma_free_chan_resources;
+ mtkd->ddev.device_tx_status = mtk_dma_tx_status;
+ mtkd->ddev.device_issue_pending = mtk_dma_issue_pending;
+ mtkd->ddev.device_prep_slave_sg = mtk_dma_prep_slave_sg;
+ mtkd->ddev.device_config = mtk_dma_slave_config;
+ mtkd->ddev.device_pause = mtk_dma_pause;
+ mtkd->ddev.device_resume = mtk_dma_resume;
+ mtkd->ddev.device_terminate_all = mtk_dma_terminate_all;
+ mtkd->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
+ mtkd->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE);
+ mtkd->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ mtkd->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+ mtkd->ddev.dev = &pdev->dev;
+ INIT_LIST_HEAD(&mtkd->ddev.channels);
+ INIT_LIST_HEAD(&mtkd->pending);
+
+ spin_lock_init(&mtkd->lock);
+
+ tasklet_init(&mtkd->task, mtk_dma_sched, (unsigned long)mtkd);
+
+ mtkd->dma_requests = MTK_SDMA_REQUESTS;
+ if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
+ "dma-requests",
+ &mtkd->dma_requests)) {
+ dev_info(&pdev->dev,
+ "Missing dma-requests property, using %u.\n",
+ MTK_SDMA_REQUESTS);
+ }
+
+ for (i = 0; i < MTK_SDMA_CHANNELS; i++) {
+ rc = mtk_dma_chan_init(mtkd);
+ if (rc) {
+ mtk_dma_free(mtkd);
+ return rc;
+ }
+ }
+
+ rc = mtk_dma_clk_enable(mtkd);
+ if (rc) {
+ pr_warn("MTK-UART-DMA: enable clk failed: %d\n",
+ rc);
+ mtk_dma_free(mtkd);
+ return rc;
+ }
+
+ rc = dma_async_device_register(&mtkd->ddev);
+ if (rc) {
+ pr_warn("MTK-UART-DMA: failed to register slave DMA engine device: %d\n",
+ rc);
+ mtk_dma_clk_disable(mtkd);
+ mtk_dma_free(mtkd);
+ return rc;
+ }
+
+ platform_set_drvdata(pdev, mtkd);
+
+ if (pdev->dev.of_node) {
+ mtk_dma_info.dma_cap = mtkd->ddev.cap_mask;
+
+ /* Device-tree DMA controller registration */
+ rc = of_dma_controller_register(pdev->dev.of_node,
+ of_dma_simple_xlate, &mtk_dma_info);
+ if (rc) {
+ pr_warn("MTK-UART-DMA: failed to register DMA controller\n");
+ dma_async_device_unregister(&mtkd->ddev);
+ mtk_dma_clk_disable(mtkd);
+ mtk_dma_free(mtkd);
+ }
+ }
+
+ return rc;
+}
+
+static int mtk_dma_remove(struct platform_device *pdev)
+{
+ struct mtk_dmadev *mtkd = platform_get_drvdata(pdev);
+
+ if (pdev->dev.of_node)
+ of_dma_controller_free(pdev->dev.of_node);
+
+ mtk_dma_clk_disable(mtkd);
+
+ dma_async_device_unregister(&mtkd->ddev);
+
+ mtk_dma_free(mtkd);
+
+ return 0;
+}
+
+static struct platform_driver mtk_dma_driver = {
+ .probe = mtk_dma_probe,
+ .remove = mtk_dma_remove,
+ .driver = {
+ .name = "mtk-uart-dma-engine",
+ .of_match_table = of_match_ptr(mtk_uart_dma_match),
+ },
+};
+
+
+static bool mtk_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+ if (chan->device->dev->driver == &mtk_dma_driver.driver) {
+ struct mtk_dmadev *mtkd = to_mtk_dma_dev(chan->device);
+ struct mtk_chan *c = to_mtk_dma_chan(chan);
+ unsigned int req = *(unsigned int *)param;
+
+ if (req <= mtkd->dma_requests) {
+ c->dma_sig = req;
+ c->dma_ch = (int)req;
+ return true;
+ }
+ }
+ return false;
+}
+
+static int mtk_dma_init(void)
+{
+ return platform_driver_register(&mtk_dma_driver);
+}
+subsys_initcall(mtk_dma_init);
+
+static void __exit mtk_dma_exit(void)
+{
+ platform_driver_unregister(&mtk_dma_driver);
+}
+module_exit(mtk_dma_exit);
+
+MODULE_DESCRIPTION("MediaTek MTK APDMA Controller Driver");
+MODULE_AUTHOR("Long Cheng (Long) <long.cheng-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>");
+MODULE_LICENSE("GPL v2");
+
--
1.7.9.5

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