[PATCH v10 2/2] dmaengine: sun6i: Add driver for the Allwinner A31 DMA controller

Maxime Ripard
2014-06-30T13:30:40Z

The Allwinner A31 has a 16 channels DMA controller that it shares with the
newer A23. Although sharing some similarities with the DMA controller of the
older Allwinner SoCs, it's significantly different, I don't expect it to be
possible to share the driver for these two.

The A31 Controller is able to memory-to-memory or memory-to-device transfers on
the 16 channels in parallel.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/dma/Kconfig | 8 +
drivers/dma/Makefile | 1 +
drivers/dma/sun6i-dma.c | 1058 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1067 insertions(+)
create mode 100644 drivers/dma/sun6i-dma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 1eca7b9760e6..4b439270fb11 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -375,6 +375,14 @@ config XILINX_VDMA
channels, Memory Mapped to Stream (MM2S) and Stream to
Memory Mapped (S2MM) for the data transfers.

+config DMA_SUN6I
+ tristate "Allwinner A31 SoCs DMA support"
+ depends on MACH_SUN6I || COMPILE_TEST
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ Support for the DMA engine for Allwinner A31 SoCs.
+
config DMA_ENGINE
bool

diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index c779e1eb2db2..6807c50214c6 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -47,3 +47,4 @@ obj-$(CONFIG_MOXART_DMA) += moxart-dma.o
obj-$(CONFIG_FSL_EDMA) += fsl-edma.o
obj-$(CONFIG_QCOM_BAM_DMA) += qcom_bam_dma.o
obj-y += xilinx/
+obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
new file mode 100644
index 000000000000..8e82694f6dc4
--- /dev/null
+++ b/drivers/dma/sun6i-dma.c
@@ -0,0 +1,1058 @@
+/*
+ * Copyright (C) 2013-2014 Allwinner Tech Co., Ltd
+ * Author: Sugar <shuge@allwinnertech.com>
+ *
+ * Copyright (C) 2014 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "virt-dma.h"
+
+/*
+ * There's 16 physical channels that can work in parallel.
+ *
+ * However we have 30 different endpoints for our requests.
+ *
+ * Since the channels are able to handle only an unidirectional
+ * transfer, we need to allocate more virtual channels so that
+ * everyone can grab one channel.
+ *
+ * Some devices can't work in both direction (mostly because it
+ * wouldn't make sense), so we have a bit fewer virtual channels than
+ * 2 channels per endpoints.
+ */
+
+#define NR_MAX_CHANNELS 16
+#define NR_MAX_REQUESTS 30
+#define NR_MAX_VCHANS 53
+
+/*
+ * Common registers
+ */
+#define DMA_IRQ_EN(x) ((x) * 0x04)
+#define DMA_IRQ_HALF BIT(0)
+#define DMA_IRQ_PKG BIT(1)
+#define DMA_IRQ_QUEUE BIT(2)
+
+#define DMA_IRQ_CHAN_NR 8
+#define DMA_IRQ_CHAN_WIDTH 4
+
+
+#define DMA_IRQ_STAT(x) ((x) * 0x04 + 0x10)
+
+#define DMA_STAT 0x30
+
+/*
+ * Channels specific registers
+ */
+#define DMA_CHAN_ENABLE 0x00
+#define DMA_CHAN_ENABLE_START BIT(0)
+#define DMA_CHAN_ENABLE_STOP 0
+
+#define DMA_CHAN_PAUSE 0x04
+#define DMA_CHAN_PAUSE_PAUSE BIT(1)
+#define DMA_CHAN_PAUSE_RESUME 0
+
+#define DMA_CHAN_LLI_ADDR 0x08
+
+#define DMA_CHAN_CUR_CFG 0x0c
+#define DMA_CHAN_CFG_SRC_DRQ(x) ((x) & 0x1f)
+#define DMA_CHAN_CFG_SRC_IO_MODE BIT(5)
+#define DMA_CHAN_CFG_SRC_LINEAR_MODE (0 << 5)
+#define DMA_CHAN_CFG_SRC_BURST(x) (((x) & 0x3) << 7)
+#define DMA_CHAN_CFG_SRC_WIDTH(x) (((x) & 0x3) << 9)
+
+#define DMA_CHAN_CFG_DST_DRQ(x) (DMA_CHAN_CFG_SRC_DRQ(x) << 16)
+#define DMA_CHAN_CFG_DST_IO_MODE (DMA_CHAN_CFG_SRC_IO_MODE << 16)
+#define DMA_CHAN_CFG_DST_LINEAR_MODE (DMA_CHAN_CFG_SRC_LINEAR_MODE << 16)
+#define DMA_CHAN_CFG_DST_BURST(x) (DMA_CHAN_CFG_SRC_BURST(x) << 16)
+#define DMA_CHAN_CFG_DST_WIDTH(x) (DMA_CHAN_CFG_SRC_WIDTH(x) << 16)
+
+#define DMA_CHAN_CUR_SRC 0x10
+
+#define DMA_CHAN_CUR_DST 0x14
+
+#define DMA_CHAN_CUR_CNT 0x18
+
+#define DMA_CHAN_CUR_PARA 0x1c
+
+
+/*
+ * Various hardware related defines
+ */
+#define LLI_LAST_ITEM 0xfffff800
+#define NORMAL_WAIT 8
+#define DRQ_SDRAM 1
+
+/*
+ * Hardware representation of the LLI
+ *
+ * The hardware will be fed the physical address of this structure,
+ * and read its content in order to start the transfer.
+ */
+struct sun6i_dma_lli {
+ u32 cfg;
+ u32 src;
+ u32 dst;
+ u32 len;
+ u32 para;
+ u32 p_lli_next;
+
+ /*
+ * This field is not used by the DMA controller, but will be
+ * used by the CPU to go through the list (mostly for dumping
+ * or freeing it).
+ */
+ struct sun6i_dma_lli *v_lli_next;
+};
+
+
+struct sun6i_desc {
+ struct virt_dma_desc vd;
+ dma_addr_t p_lli;
+ struct sun6i_dma_lli *v_lli;
+};
+
+struct sun6i_pchan {
+ u32 idx;
+ void __iomem *base;
+ struct sun6i_vchan *vchan;
+ struct sun6i_desc *desc;
+ struct sun6i_desc *done;
+};
+
+struct sun6i_vchan {
+ struct virt_dma_chan vc;
+ struct list_head node;
+ struct dma_slave_config cfg;
+ struct sun6i_pchan *phy;
+ u8 port;
+};
+
+struct sun6i_dma_dev {
+ struct dma_device slave;
+ void __iomem *base;
+ struct clk *clk;
+ int irq;
+ spinlock_t lock;
+ struct reset_control *rstc;
+ struct tasklet_struct task;
+ atomic_t tasklet_shutdown;
+ struct list_head pending;
+ struct dma_pool *pool;
+ struct sun6i_pchan *pchans;
+ struct sun6i_vchan *vchans;
+};
+
+static struct device *chan2dev(struct dma_chan *chan)
+{
+ return &chan->dev->device;
+}
+
+static inline struct sun6i_dma_dev *to_sun6i_dma_dev(struct dma_device *d)
+{
+ return container_of(d, struct sun6i_dma_dev, slave);
+}
+
+static inline struct sun6i_vchan *to_sun6i_vchan(struct dma_chan *chan)
+{
+ return container_of(chan, struct sun6i_vchan, vc.chan);
+}
+
+static inline struct sun6i_desc *
+to_sun6i_desc(struct dma_async_tx_descriptor *tx)
+{
+ return container_of(tx, struct sun6i_desc, vd.tx);
+}
+
+static inline void sun6i_dma_dump_com_regs(struct sun6i_dma_dev *sdev)
+{
+ dev_dbg(sdev->slave.dev, "Common register:\n"
+ "\tmask0(%04x): 0x%08x\n"
+ "\tmask1(%04x): 0x%08x\n"
+ "\tpend0(%04x): 0x%08x\n"
+ "\tpend1(%04x): 0x%08x\n"
+ "\tstats(%04x): 0x%08x\n",
+ DMA_IRQ_EN(0), readl(sdev->base + DMA_IRQ_EN(0)),
+ DMA_IRQ_EN(1), readl(sdev->base + DMA_IRQ_EN(1)),
+ DMA_IRQ_STAT(0), readl(sdev->base + DMA_IRQ_STAT(0)),
+ DMA_IRQ_STAT(1), readl(sdev->base + DMA_IRQ_STAT(1)),
+ DMA_STAT, readl(sdev->base + DMA_STAT));
+}
+
+static inline void sun6i_dma_dump_chan_regs(struct sun6i_dma_dev *sdev,
+ struct sun6i_pchan *pchan)
+{
+ phys_addr_t reg = __virt_to_phys((unsigned long)pchan->base);
+
+ dev_dbg(sdev->slave.dev, "Chan %d reg: %pa\n"
+ "\t___en(%04x): \t0x%08x\n"
+ "\tpause(%04x): \t0x%08x\n"
+ "\tstart(%04x): \t0x%08x\n"
+ "\t__cfg(%04x): \t0x%08x\n"
+ "\t__src(%04x): \t0x%08x\n"
+ "\t__dst(%04x): \t0x%08x\n"
+ "\tcount(%04x): \t0x%08x\n"
+ "\t_para(%04x): \t0x%08x\n\n",
+ pchan->idx, &reg,
+ DMA_CHAN_ENABLE,
+ readl(pchan->base + DMA_CHAN_ENABLE),
+ DMA_CHAN_PAUSE,
+ readl(pchan->base + DMA_CHAN_PAUSE),
+ DMA_CHAN_LLI_ADDR,
+ readl(pchan->base + DMA_CHAN_LLI_ADDR),
+ DMA_CHAN_CUR_CFG,
+ readl(pchan->base + DMA_CHAN_CUR_CFG),
+ DMA_CHAN_CUR_SRC,
+ readl(pchan->base + DMA_CHAN_CUR_SRC),
+ DMA_CHAN_CUR_DST,
+ readl(pchan->base + DMA_CHAN_CUR_DST),
+ DMA_CHAN_CUR_CNT,
+ readl(pchan->base + DMA_CHAN_CUR_CNT),
+ DMA_CHAN_CUR_PARA,
+ readl(pchan->base + DMA_CHAN_CUR_PARA));
+}
+
+static inline int convert_burst(u32 maxburst, u8 *burst)
+{
+ switch (maxburst) {
+ case 1:
+ *burst = 0;
+ break;
+ case 8:
+ *burst = 2;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static inline int convert_buswidth(enum dma_slave_buswidth addr_width, u8 *width)
+{
+ switch (addr_width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ *width = 0;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ *width = 1;
+ break;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ *width = 2;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void *sun6i_dma_lli_add(struct sun6i_dma_lli *prev,
+ struct sun6i_dma_lli *next,
+ dma_addr_t next_phy,
+ struct sun6i_desc *txd)
+{
+ if ((!prev && !txd) || !next)
+ return NULL;
+
+ if (!prev) {
+ txd->p_lli = next_phy;
+ txd->v_lli = next;
+ } else {
+ prev->p_lli_next = next_phy;
+ prev->v_lli_next = next;
+ }
+
+ next->p_lli_next = LLI_LAST_ITEM;
+ next->v_lli_next = NULL;
+
+ return next;
+}
+
+static inline int sun6i_dma_cfg_lli(struct sun6i_dma_lli *lli,
+ dma_addr_t src,
+ dma_addr_t dst, u32 len,
+ struct dma_slave_config *config)
+{
+ u8 src_width, dst_width, src_burst, dst_burst;
+ int ret;
+
+ if (!config)
+ return -EINVAL;
+
+ ret = convert_burst(config->src_maxburst, &src_burst);
+ if (ret)
+ return ret;
+
+ ret = convert_burst(config->dst_maxburst, &dst_burst);
+ if (ret)
+ return ret;
+
+ ret = convert_buswidth(config->src_addr_width, &src_width);
+ if (ret)
+ return ret;
+
+ ret = convert_buswidth(config->dst_addr_width, &dst_width);
+ if (ret)
+ return ret;
+
+ lli->cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) |
+ DMA_CHAN_CFG_SRC_WIDTH(src_width) |
+ DMA_CHAN_CFG_DST_BURST(dst_burst) |
+ DMA_CHAN_CFG_DST_WIDTH(dst_width);
+
+ lli->src = src;
+ lli->dst = dst;
+ lli->len = len;
+ lli->para = NORMAL_WAIT;
+
+ return 0;
+}
+
+static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan,
+ struct sun6i_dma_lli *lli)
+{
+ phys_addr_t p_lli = __virt_to_phys((unsigned long)lli);
+
+ dev_dbg(chan2dev(&vchan->vc.chan),
+ "\n\tdesc: p - %pa v - 0x%p\n"
+ "\t\tc - 0x%08x s - 0x%08x d - 0x%08x\n"
+ "\t\tl - 0x%08x p - 0x%08x n - 0x%08x\n",
+ &p_lli, lli,
+ lli->cfg, lli->src, lli->dst,
+ lli->len, lli->para, lli->p_lli_next);
+}
+
+static void sun6i_dma_free_desc(struct virt_dma_desc *vd)
+{
+ struct sun6i_desc *txd = to_sun6i_desc(&vd->tx);
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device);
+ struct sun6i_dma_lli *v_lli, *v_next;
+ dma_addr_t p_lli, p_next;
+
+ if (unlikely(!txd))
+ return;
+
+ p_lli = txd->p_lli;
+ v_lli = txd->v_lli;
+
+ while (v_lli) {
+ v_next = v_lli->v_lli_next;
+ p_next = v_lli->p_lli_next;
+
+ dma_pool_free(sdev->pool, v_lli, p_lli);
+
+ v_lli = v_next;
+ p_lli = p_next;
+ }
+
+ kfree(txd);
+}
+
+static int sun6i_dma_terminate_all(struct sun6i_vchan *vchan)
+{
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
+ struct sun6i_pchan *pchan = vchan->phy;
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock(&sdev->lock);
+ list_del_init(&vchan->node);
+ spin_unlock(&sdev->lock);
+
+ spin_lock_irqsave(&vchan->vc.lock, flags);
+
+ vchan_get_all_descriptors(&vchan->vc, &head);
+
+ if (pchan) {
+ writel(DMA_CHAN_ENABLE_STOP, pchan->base + DMA_CHAN_ENABLE);
+ writel(DMA_CHAN_PAUSE_RESUME, pchan->base + DMA_CHAN_PAUSE);
+
+ vchan->phy = NULL;
+ pchan->vchan = NULL;
+ pchan->desc = NULL;
+ pchan->done = NULL;
+ }
+
+ spin_unlock_irqrestore(&vchan->vc.lock, flags);
+
+ vchan_dma_desc_free_list(&vchan->vc, &head);
+
+ return 0;
+}
+
+static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
+{
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
+ struct virt_dma_desc *desc = vchan_next_desc(&vchan->vc);
+ struct sun6i_pchan *pchan = vchan->phy;
+ u32 irq_val, irq_reg, irq_offset;
+
+ if (!pchan)
+ return -EAGAIN;
+
+ if (!desc) {
+ pchan->desc = NULL;
+ pchan->done = NULL;
+ return -EAGAIN;
+ }
+
+ list_del(&desc->node);
+
+ pchan->desc = to_sun6i_desc(&desc->tx);
+ pchan->done = NULL;
+
+ sun6i_dma_dump_lli(vchan, pchan->desc->v_lli);
+
+ irq_reg = pchan->idx / DMA_IRQ_CHAN_NR;
+ irq_offset = pchan->idx % DMA_IRQ_CHAN_NR;
+
+ irq_val = readl(sdev->base + DMA_IRQ_EN(irq_offset));
+ irq_val |= DMA_IRQ_QUEUE << (irq_offset * DMA_IRQ_CHAN_WIDTH);
+ writel(irq_val, sdev->base + DMA_IRQ_EN(irq_offset));
+
+ writel(pchan->desc->p_lli, pchan->base + DMA_CHAN_LLI_ADDR);
+ writel(DMA_CHAN_ENABLE_START, pchan->base + DMA_CHAN_ENABLE);
+
+ sun6i_dma_dump_com_regs(sdev);
+ sun6i_dma_dump_chan_regs(sdev, pchan);
+
+ return 0;
+}
+
+static void sun6i_dma_tasklet(unsigned long data)
+{
+ struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)data;
+ struct sun6i_vchan *vchan;
+ struct sun6i_pchan *pchan;
+ unsigned int pchan_alloc = 0;
+ unsigned int pchan_idx;
+
+ list_for_each_entry(vchan, &sdev->slave.channels, vc.chan.device_node) {
+ spin_lock_irq(&vchan->vc.lock);
+
+ pchan = vchan->phy;
+
+ if (pchan && pchan->done) {
+ if (sun6i_dma_start_desc(vchan)) {
+ /*
+ * No current txd associated with this channel
+ */
+ dev_dbg(sdev->slave.dev, "pchan %u: free\n",
+ pchan->idx);
+
+ /* Mark this channel free */
+ vchan->phy = NULL;
+ pchan->vchan = NULL;
+ }
+ }
+ spin_unlock_irq(&vchan->vc.lock);
+ }
+
+ spin_lock_irq(&sdev->lock);
+ for (pchan_idx = 0; pchan_idx < NR_MAX_CHANNELS; pchan_idx++) {
+ pchan = &sdev->pchans[pchan_idx];
+
+ if (pchan->vchan || list_empty(&sdev->pending))
+ continue;
+
+ vchan = list_first_entry(&sdev->pending,
+ struct sun6i_vchan, node);
+
+ /* Remove from pending channels */
+ list_del_init(&vchan->node);
+ pchan_alloc |= BIT(pchan_idx);
+
+ /* Mark this channel allocated */
+ pchan->vchan = vchan;
+ vchan->phy = pchan;
+ dev_dbg(sdev->slave.dev, "pchan %u: alloc vchan %p\n",
+ pchan->idx, &vchan->vc);
+ }
+ spin_unlock_irq(&sdev->lock);
+
+ for (pchan_idx = 0; pchan_idx < NR_MAX_CHANNELS; pchan_idx++) {
+ if (!(pchan_alloc & BIT(pchan_idx)))
+ continue;
+
+ pchan = sdev->pchans + pchan_idx;
+ vchan = pchan->vchan;
+ if (vchan) {
+ spin_lock_irq(&vchan->vc.lock);
+ sun6i_dma_start_desc(vchan);
+ spin_unlock_irq(&vchan->vc.lock);
+ }
+ }
+}
+
+static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
+{
+ struct sun6i_dma_dev *sdev = dev_id;
+ struct sun6i_vchan *vchan;
+ struct sun6i_pchan *pchan;
+ int i, j, ret = IRQ_NONE;
+ u32 status;
+
+ for (i = 0; i < 2; i++) {
+ status = readl(sdev->base + DMA_IRQ_STAT(i));
+ if (!status)
+ continue;
+
+ dev_dbg(sdev->slave.dev, "DMA irq status %s: 0x%x\n",
+ i ? "high" : "low", status);
+
+ writel(status, sdev->base + DMA_IRQ_STAT(i));
+
+ for (j = 0; (j < 8) && status; j++) {
+ if (status & DMA_IRQ_QUEUE) {
+ pchan = sdev->pchans + j;
+ vchan = pchan->vchan;
+
+ if (vchan) {
+ spin_lock(&vchan->vc.lock);
+ vchan_cookie_complete(&pchan->desc->vd);
+ pchan->done = pchan->desc;
+ spin_unlock(&vchan->vc.lock);
+ }
+ }
+
+ status = status >> 4;
+ }
+
+ if (!atomic_read(&sdev->tasklet_shutdown))
+ tasklet_schedule(&sdev->task);
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
+ struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+ size_t len, unsigned long flags)
+{
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+ struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+ struct dma_slave_config *sconfig = &vchan->cfg;
+ struct sun6i_dma_lli *v_lli;
+ struct sun6i_desc *txd;
+ dma_addr_t p_lli;
+ int ret;
+
+ dev_dbg(chan2dev(chan),
+ "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
+ __func__, vchan->vc.chan.chan_id, &dest, &src, len, flags);
+
+ if (!len)
+ return NULL;
+
+ txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
+ if (!txd)
+ return NULL;
+
+ v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
+ if (!v_lli) {
+ dev_err(sdev->slave.dev, "Failed to alloc lli memory\n");
+ kfree(txd);
+ return NULL;
+ }
+
+ ret = sun6i_dma_cfg_lli(v_lli, src, dest, len, sconfig);
+ if (ret)
+ goto err_dma_free;
+
+ v_lli->cfg |= DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
+ DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
+ DMA_CHAN_CFG_DST_LINEAR_MODE |
+ DMA_CHAN_CFG_SRC_LINEAR_MODE;
+
+ sun6i_dma_lli_add(NULL, v_lli, p_lli, txd);
+
+ sun6i_dma_dump_lli(vchan, v_lli);
+
+ return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
+
+err_dma_free:
+ dma_pool_free(sdev->pool, v_lli, p_lli);
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_transfer_direction dir,
+ unsigned long flags, void *context)
+{
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+ struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+ struct dma_slave_config *sconfig = &vchan->cfg;
+ struct sun6i_dma_lli *v_lli, *prev = NULL;
+ struct sun6i_desc *txd;
+ struct scatterlist *sg;
+ dma_addr_t p_lli;
+ int i, ret;
+
+ if (!sgl)
+ return NULL;
+
+ if (!is_slave_direction(dir)) {
+ dev_err(chan2dev(chan), "Invalid DMA direction\n");
+ return NULL;
+ }
+
+ txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
+ if (!txd)
+ return NULL;
+
+ for_each_sg(sgl, sg, sg_len, i) {
+ v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
+ if (!v_lli) {
+ kfree(txd);
+ return NULL;
+ }
+
+ if (dir == DMA_MEM_TO_DEV) {
+ ret = sun6i_dma_cfg_lli(v_lli, sg_dma_address(sg),
+ sconfig->dst_addr, sg_dma_len(sg),
+ sconfig);
+ if (ret)
+ goto err_dma_free;
+
+ v_lli->cfg |= DMA_CHAN_CFG_DST_IO_MODE |
+ DMA_CHAN_CFG_SRC_LINEAR_MODE |
+ DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
+ DMA_CHAN_CFG_DST_DRQ(vchan->port);
+
+ dev_dbg(chan2dev(chan),
+ "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
+ __func__, vchan->vc.chan.chan_id,
+ &sconfig->dst_addr, &sg_dma_address(sg),
+ sg_dma_len(sg), flags);
+
+ } else {
+ ret = sun6i_dma_cfg_lli(v_lli, sconfig->src_addr,
+ sg_dma_address(sg), sg_dma_len(sg),
+ sconfig);
+ if (ret)
+ goto err_dma_free;
+
+ v_lli->cfg |= DMA_CHAN_CFG_DST_LINEAR_MODE |
+ DMA_CHAN_CFG_SRC_IO_MODE |
+ DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
+ DMA_CHAN_CFG_SRC_DRQ(vchan->port);
+
+ dev_dbg(chan2dev(chan),
+ "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
+ __func__, vchan->vc.chan.chan_id,
+ &sg_dma_address(sg), &sconfig->src_addr,
+ sg_dma_len(sg), flags);
+ }
+
+ prev = sun6i_dma_lli_add(prev, v_lli, p_lli, txd);
+ }
+
+ dev_dbg(chan2dev(chan), "First: %pad\n", &txd->p_lli);
+ for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
+ sun6i_dma_dump_lli(vchan, prev);
+
+ return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
+
+err_dma_free:
+ dma_pool_free(sdev->pool, v_lli, p_lli);
+ return NULL;
+}
+
+static int sun6i_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+ struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+ struct sun6i_pchan *pchan = vchan->phy;
+ unsigned long flags;
+ int ret = 0;
+
+ switch (cmd) {
+ case DMA_RESUME:
+ dev_dbg(chan2dev(chan), "vchan %p: resume\n", &vchan->vc);
+
+ spin_lock_irqsave(&vchan->vc.lock, flags);
+
+ if (pchan) {
+ writel(DMA_CHAN_PAUSE_RESUME,
+ pchan->base + DMA_CHAN_PAUSE);
+ } else if (!list_empty(&vchan->vc.desc_issued)) {
+ spin_lock(&sdev->lock);
+ list_add_tail(&vchan->node, &sdev->pending);
+ spin_unlock(&sdev->lock);
+ }
+
+ spin_unlock_irqrestore(&vchan->vc.lock, flags);
+ break;
+
+ case DMA_PAUSE:
+ dev_dbg(chan2dev(chan), "vchan %p: pause\n", &vchan->vc);
+
+ if (pchan) {
+ writel(DMA_CHAN_PAUSE_PAUSE,
+ pchan->base + DMA_CHAN_PAUSE);
+ } else {
+ spin_lock(&sdev->lock);
+ list_del_init(&vchan->node);
+ spin_unlock(&sdev->lock);
+ }
+ break;
+
+ case DMA_TERMINATE_ALL:
+ ret = sun6i_dma_terminate_all(vchan);
+ break;
+ case DMA_SLAVE_CONFIG:
+ memcpy(&vchan->cfg, (void *)arg, sizeof(struct dma_slave_config));
+ break;
+ default:
+ ret = -ENXIO;
+ break;
+ }
+ return ret;
+}
+
+static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *state)
+{
+ struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+ struct sun6i_pchan *pchan = vchan->phy;
+ struct sun6i_dma_lli *lli;
+ struct virt_dma_desc *vd;
+ struct sun6i_desc *txd;
+ enum dma_status ret;
+ unsigned long flags;
+ size_t bytes = 0;
+
+ ret = dma_cookie_status(chan, cookie, state);
+ if (ret == DMA_COMPLETE)
+ return ret;
+
+ spin_lock_irqsave(&vchan->vc.lock, flags);
+
+ vd = vchan_find_desc(&vchan->vc, cookie);
+ txd = to_sun6i_desc(&vd->tx);
+
+ if (vd) {
+ for (lli = txd->v_lli; lli != NULL; lli = lli->v_lli_next)
+ bytes += lli->len;
+ } else if (!pchan || !pchan->desc) {
+ bytes = 0;
+ } else {
+ bytes = readl(pchan->base + DMA_CHAN_CUR_CNT);
+ }
+
+ spin_unlock_irqrestore(&vchan->vc.lock, flags);
+
+ dma_set_residue(state, bytes);
+
+ return ret;
+}
+
+static void sun6i_dma_issue_pending(struct dma_chan *chan)
+{
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+ struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&vchan->vc.lock, flags);
+
+ if (vchan_issue_pending(&vchan->vc)) {
+ spin_lock(&sdev->lock);
+
+ if (!vchan->phy && list_empty(&vchan->node)) {
+ list_add_tail(&vchan->node, &sdev->pending);
+ tasklet_schedule(&sdev->task);
+ dev_dbg(chan2dev(chan), "vchan %p: issued\n",
+ &vchan->vc);
+ }
+
+ spin_unlock(&sdev->lock);
+ } else {
+ dev_dbg(chan2dev(chan), "vchan %p: nothing to issue\n",
+ &vchan->vc);
+ }
+
+ spin_unlock_irqrestore(&vchan->vc.lock, flags);
+}
+
+static int sun6i_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+ return 0;
+}
+
+static void sun6i_dma_free_chan_resources(struct dma_chan *chan)
+{
+ struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
+ struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&sdev->lock, flags);
+ list_del_init(&vchan->node);
+ spin_unlock_irqrestore(&sdev->lock, flags);
+
+ vchan_free_chan_resources(&vchan->vc);
+}
+
+static struct dma_chan *sun6i_dma_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct sun6i_dma_dev *sdev = ofdma->of_dma_data;
+ struct sun6i_vchan *vchan;
+ struct dma_chan *chan;
+ u8 port = dma_spec->args[0];
+
+ if (port > NR_MAX_REQUESTS)
+ return NULL;
+
+ chan = dma_get_any_slave_channel(&sdev->slave);
+ if (!chan)
+ return NULL;
+
+ vchan = to_sun6i_vchan(chan);
+ vchan->port = port;
+
+ return chan;
+}
+
+static inline void sun6i_kill_tasklet(struct sun6i_dma_dev *sdev)
+{
+ /* Disable all interrupts from DMA */
+ writel(0, sdev->base + DMA_IRQ_EN(0));
+ writel(0, sdev->base + DMA_IRQ_EN(1));
+
+ /* Prevent spurious interrupts from scheduling the tasklet */
+ atomic_inc(&sdev->tasklet_shutdown);
+
+ /* Make sure all interrupts are handled */
+ synchronize_irq(sdev->irq);
+
+ /* Actually prevent the tasklet from being scheduled */
+ tasklet_kill(&sdev->task);
+}
+
+static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
+{
+ int i;
+
+ for (i = 0; i < NR_MAX_VCHANS; i++) {
+ struct sun6i_vchan *vchan = &sdev->vchans[i];
+
+ list_del(&vchan->vc.chan.device_node);
+ tasklet_kill(&vchan->vc.task);
+ }
+}
+
+static int sun6i_dma_probe(struct platform_device *pdev)
+{
+ struct sun6i_dma_dev *sdc;
+ struct resource *res;
+ struct clk *mux, *pll6;
+ int ret, i;
+
+ sdc = devm_kzalloc(&pdev->dev, sizeof(*sdc), GFP_KERNEL);
+ if (!sdc)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ sdc->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(sdc->base))
+ return PTR_ERR(sdc->base);
+
+ sdc->irq = platform_get_irq(pdev, 0);
+ if (sdc->irq < 0) {
+ dev_err(&pdev->dev, "Cannot claim IRQ\n");
+ return sdc->irq;
+ }
+
+ sdc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(sdc->clk)) {
+ dev_err(&pdev->dev, "No clock specified\n");
+ return PTR_ERR(sdc->clk);
+ }
+
+ mux = clk_get(NULL, "ahb1_mux");
+ if (IS_ERR(mux)) {
+ dev_err(&pdev->dev, "Couldn't get AHB1 Mux\n");
+ return PTR_ERR(mux);
+ }
+
+ pll6 = clk_get(NULL, "pll6");
+ if (IS_ERR(pll6)) {
+ dev_err(&pdev->dev, "Couldn't get PLL6\n");
+ clk_put(mux);
+ return PTR_ERR(pll6);
+ }
+
+ ret = clk_set_parent(mux, pll6);
+ clk_put(pll6);
+ clk_put(mux);
+
+ if (ret) {
+ dev_err(&pdev->dev, "Couldn't reparent AHB1 on PLL6\n");
+ return ret;
+ }
+
+ sdc->rstc = devm_reset_control_get(&pdev->dev, NULL);
+ if (IS_ERR(sdc->rstc)) {
+ dev_err(&pdev->dev, "No reset controller specified\n");
+ return PTR_ERR(sdc->rstc);
+ }
+
+ sdc->pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
+ sizeof(struct sun6i_dma_lli), 4, 0);
+ if (!sdc->pool) {
+ dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
+ return -ENOMEM;
+ }
+
+ platform_set_drvdata(pdev, sdc);
+ INIT_LIST_HEAD(&sdc->pending);
+ spin_lock_init(&sdc->lock);
+
+ dma_cap_set(DMA_PRIVATE, sdc->slave.cap_mask);
+ dma_cap_set(DMA_MEMCPY, sdc->slave.cap_mask);
+ dma_cap_set(DMA_SLAVE, sdc->slave.cap_mask);
+
+ INIT_LIST_HEAD(&sdc->slave.channels);
+ sdc->slave.device_alloc_chan_resources = sun6i_dma_alloc_chan_resources;
+ sdc->slave.device_free_chan_resources = sun6i_dma_free_chan_resources;
+ sdc->slave.device_tx_status = sun6i_dma_tx_status;
+ sdc->slave.device_issue_pending = sun6i_dma_issue_pending;
+ sdc->slave.device_prep_slave_sg = sun6i_dma_prep_slave_sg;
+ sdc->slave.device_prep_dma_memcpy = sun6i_dma_prep_dma_memcpy;
+ sdc->slave.device_control = sun6i_dma_control;
+ sdc->slave.chancnt = NR_MAX_VCHANS;
+
+ sdc->slave.dev = &pdev->dev;
+
+ sdc->pchans = devm_kcalloc(&pdev->dev, NR_MAX_CHANNELS,
+ sizeof(struct sun6i_pchan), GFP_KERNEL);
+ if (!sdc->pchans)
+ return -ENOMEM;
+
+ sdc->vchans = devm_kcalloc(&pdev->dev, NR_MAX_VCHANS,
+ sizeof(struct sun6i_vchan), GFP_KERNEL);
+ if (!sdc->vchans)
+ return -ENOMEM;
+
+ tasklet_init(&sdc->task, sun6i_dma_tasklet, (unsigned long)sdc);
+
+ for (i = 0; i < NR_MAX_CHANNELS; i++) {
+ struct sun6i_pchan *pchan = &sdc->pchans[i];
+
+ pchan->idx = i;
+ pchan->base = sdc->base + 0x100 + i * 0x40;
+ }
+
+ for (i = 0; i < NR_MAX_VCHANS; i++) {
+ struct sun6i_vchan *vchan = &sdc->vchans[i];
+
+ INIT_LIST_HEAD(&vchan->node);
+ vchan->vc.desc_free = sun6i_dma_free_desc;
+ vchan_init(&vchan->vc, &sdc->slave);
+ }
+
+ ret = reset_control_deassert(sdc->rstc);
+ if (ret) {
+ dev_err(&pdev->dev, "Couldn't deassert the device from reset\n");
+ goto err_chan_free;
+ }
+
+ ret = clk_prepare_enable(sdc->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Couldn't enable the clock\n");
+ goto err_reset_assert;
+ }
+
+ ret = devm_request_irq(&pdev->dev, sdc->irq, sun6i_dma_interrupt, 0,
+ dev_name(&pdev->dev), sdc);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot request IRQ\n");
+ goto err_clk_disable;
+ }
+
+ ret = dma_async_device_register(&sdc->slave);
+ if (ret) {
+ dev_warn(&pdev->dev, "Failed to register DMA engine device\n");
+ goto err_irq_disable;
+ }
+
+ ret = of_dma_controller_register(pdev->dev.of_node, sun6i_dma_of_xlate,
+ sdc);
+ if (ret) {
+ dev_err(&pdev->dev, "of_dma_controller_register failed\n");
+ goto err_dma_unregister;
+ }
+
+ return 0;
+
+err_dma_unregister:
+ dma_async_device_unregister(&sdc->slave);
+err_irq_disable:
+ sun6i_kill_tasklet(sdc);
+err_clk_disable:
+ clk_disable_unprepare(sdc->clk);
+err_reset_assert:
+ reset_control_assert(sdc->rstc);
+err_chan_free:
+ sun6i_dma_free(sdc);
+ return ret;
+}
+
+static int sun6i_dma_remove(struct platform_device *pdev)
+{
+ struct sun6i_dma_dev *sdc = platform_get_drvdata(pdev);
+
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&sdc->slave);
+
+ sun6i_kill_tasklet(sdc);
+
+ clk_disable_unprepare(sdc->clk);
+ reset_control_assert(sdc->rstc);
+
+ sun6i_dma_free(sdc);
+
+ return 0;
+}
+
+static struct of_device_id sun6i_dma_match[] = {
+ { .compatible = "allwinner,sun6i-a31-dma" }
+};
+
+static struct platform_driver sun6i_dma_driver = {
+ .probe = sun6i_dma_probe,
+ .remove = sun6i_dma_remove,
+ .driver = {
+ .name = "sun6i-dma",
+ .of_match_table = sun6i_dma_match,
+ },
+};
+module_platform_driver(sun6i_dma_driver);
+
+MODULE_DESCRIPTION("Allwinner A31 DMA Controller Driver");
+MODULE_AUTHOR("Sugar <shuge@allwinnertech.com>");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_LICENSE("GPL");
--
2.0.0