dmaengine: loongson2-apb: Rename the prefix ls2x to loongson2
authorBinbin Zhou <zhoubinbin@loongson.cn>
Tue, 24 Sep 2024 06:42:41 +0000 (14:42 +0800)
committerVinod Koul <vkoul@kernel.org>
Wed, 23 Oct 2024 05:35:45 +0000 (11:05 +0530)
Since commit e06c43231214 ("dmaengine: Loongson1: Add Loongson-1 APB DMA
driver"), the Loongson-1 dma controller was added.

Unfortunately their naming has not been standardized, as CPUs belonging
to the same Loongson family, we expect to standardize the naming for
ease of understanding.

Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://lore.kernel.org/r/20240924064241.2414629-1-zhoubinbin@loongson.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>
MAINTAINERS
arch/loongarch/configs/loongson3_defconfig
drivers/dma/Kconfig
drivers/dma/Makefile
drivers/dma/loongson2-apb-dma.c [new file with mode: 0644]
drivers/dma/ls2x-apb-dma.c [deleted file]

index c27f3190737f8b85779bde5489639c8b899f4fd8..c5cda5ad4022f668ab1713e8a4aef15a2dfb9e05 100644 (file)
@@ -13369,12 +13369,12 @@ S:    Maintained
 F:     Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
 F:     drivers/gpio/gpio-loongson-64bit.c
 
-LOONGSON LS2X APB DMA DRIVER
+LOONGSON-2 APB DMA DRIVER
 M:     Binbin Zhou <zhoubinbin@loongson.cn>
 L:     dmaengine@vger.kernel.org
 S:     Maintained
 F:     Documentation/devicetree/bindings/dma/loongson,ls2x-apbdma.yaml
-F:     drivers/dma/ls2x-apb-dma.c
+F:     drivers/dma/loongson2-apb-dma.c
 
 LOONGSON LS2X I2C DRIVER
 M:     Binbin Zhou <zhoubinbin@loongson.cn>
index 75b366407a60a39803cab69efcb3bdf70ee12b3f..6dfedda930a240236de10b390d345b8ceca4db96 100644 (file)
@@ -775,7 +775,7 @@ CONFIG_RTC_CLASS=y
 CONFIG_RTC_DRV_EFI=y
 CONFIG_RTC_DRV_LOONGSON=y
 CONFIG_DMADEVICES=y
-CONFIG_LS2X_APB_DMA=y
+CONFIG_LOONGSON2_APB_DMA=y
 CONFIG_UDMABUF=y
 CONFIG_DMABUF_HEAPS=y
 CONFIG_DMABUF_HEAPS_SYSTEM=y
index d9ec1e69e4283188e8c37f0e349eb106ef225f2f..e994d6e0779e02d7af20e7da83b5c2ca485f6d52 100644 (file)
@@ -378,6 +378,20 @@ config LOONGSON1_APB_DMA
          This selects support for the APB DMA controller in Loongson1 SoCs,
          which is required by Loongson1 NAND and audio support.
 
+config LOONGSON2_APB_DMA
+       tristate "Loongson2 APB DMA support"
+       depends on LOONGARCH || COMPILE_TEST
+       select DMA_ENGINE
+       select DMA_VIRTUAL_CHANNELS
+       help
+         Support for the Loongson2 APB DMA controller driver. The
+         DMA controller is having single DMA channel which can be
+         configured for different peripherals like audio, nand, sdio
+         etc which is in APB bus.
+
+         This DMA controller transfers data from memory to peripheral fifo.
+         It does not support memory to memory data transfer.
+
 config LPC18XX_DMAMUX
        bool "NXP LPC18xx/43xx DMA MUX for PL080"
        depends on ARCH_LPC18XX || COMPILE_TEST
@@ -396,20 +410,6 @@ config LPC32XX_DMAMUX
          Support for PL080 multiplexed DMA request lines on
          LPC32XX platrofm.
 
-config LS2X_APB_DMA
-       tristate "Loongson LS2X APB DMA support"
-       depends on LOONGARCH || COMPILE_TEST
-       select DMA_ENGINE
-       select DMA_VIRTUAL_CHANNELS
-       help
-         Support for the Loongson LS2X APB DMA controller driver. The
-         DMA controller is having single DMA channel which can be
-         configured for different peripherals like audio, nand, sdio
-         etc which is in APB bus.
-
-         This DMA controller transfers data from memory to peripheral fifo.
-         It does not support memory to memory data transfer.
-
 config MCF_EDMA
        tristate "Freescale eDMA engine support, ColdFire mcf5441x SoCs"
        depends on M5441x || (COMPILE_TEST && FSL_EDMA=n)
index ad6a03c052ec4a7ebbdc7c2e29384d27d27e0478..5b2a52f4f2ee99bf36bcce8bd3b30b7d8bbcc871 100644 (file)
@@ -50,9 +50,9 @@ obj-$(CONFIG_INTEL_IOATDMA) += ioat/
 obj-y += idxd/
 obj-$(CONFIG_K3_DMA) += k3dma.o
 obj-$(CONFIG_LOONGSON1_APB_DMA) += loongson1-apb-dma.o
+obj-$(CONFIG_LOONGSON2_APB_DMA) += loongson2-apb-dma.o
 obj-$(CONFIG_LPC18XX_DMAMUX) += lpc18xx-dmamux.o
 obj-$(CONFIG_LPC32XX_DMAMUX) += lpc32xx-dmamux.o
-obj-$(CONFIG_LS2X_APB_DMA) += ls2x-apb-dma.o
 obj-$(CONFIG_MILBEAUT_HDMAC) += milbeaut-hdmac.o
 obj-$(CONFIG_MILBEAUT_XDMAC) += milbeaut-xdmac.o
 obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
diff --git a/drivers/dma/loongson2-apb-dma.c b/drivers/dma/loongson2-apb-dma.c
new file mode 100644 (file)
index 0000000..367ed34
--- /dev/null
@@ -0,0 +1,705 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for the Loongson-2 APB DMA Controller
+ *
+ * Copyright (C) 2017-2023 Loongson Corporation
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+/* Global Configuration Register */
+#define LDMA_ORDER_ERG         0x0
+
+/* Bitfield definitions */
+
+/* Bitfields in Global Configuration Register */
+#define LDMA_64BIT_EN          BIT(0) /* 1: 64 bit support */
+#define LDMA_UNCOHERENT_EN     BIT(1) /* 0: cache, 1: uncache */
+#define LDMA_ASK_VALID         BIT(2)
+#define LDMA_START             BIT(3) /* DMA start operation */
+#define LDMA_STOP              BIT(4) /* DMA stop operation */
+#define LDMA_CONFIG_MASK       GENMASK(4, 0) /* DMA controller config bits mask */
+
+/* Bitfields in ndesc_addr field of HW descriptor */
+#define LDMA_DESC_EN           BIT(0) /*1: The next descriptor is valid */
+#define LDMA_DESC_ADDR_LOW     GENMASK(31, 1)
+
+/* Bitfields in cmd field of HW descriptor */
+#define LDMA_INT               BIT(1) /* Enable DMA interrupts */
+#define LDMA_DATA_DIRECTION    BIT(12) /* 1: write to device, 0: read from device */
+
+#define LDMA_SLAVE_BUSWIDTHS   (BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
+                                BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
+
+#define LDMA_MAX_TRANS_LEN     U32_MAX
+
+/*--  descriptors  -----------------------------------------------------*/
+
+/*
+ * struct ls2x_dma_hw_desc - DMA HW descriptor
+ * @ndesc_addr: the next descriptor low address.
+ * @mem_addr: memory low address.
+ * @apb_addr: device buffer address.
+ * @len: length of a piece of carried content, in words.
+ * @step_len: length between two moved memory data blocks.
+ * @step_times: number of blocks to be carried in a single DMA operation.
+ * @cmd: descriptor command or state.
+ * @stats: DMA status.
+ * @high_ndesc_addr: the next descriptor high address.
+ * @high_mem_addr: memory high address.
+ * @reserved: reserved
+ */
+struct ls2x_dma_hw_desc {
+       u32 ndesc_addr;
+       u32 mem_addr;
+       u32 apb_addr;
+       u32 len;
+       u32 step_len;
+       u32 step_times;
+       u32 cmd;
+       u32 stats;
+       u32 high_ndesc_addr;
+       u32 high_mem_addr;
+       u32 reserved[2];
+} __packed;
+
+/*
+ * struct ls2x_dma_sg - ls2x dma scatter gather entry
+ * @hw: the pointer to DMA HW descriptor.
+ * @llp: physical address of the DMA HW descriptor.
+ * @phys: destination or source address(mem).
+ * @len: number of Bytes to read.
+ */
+struct ls2x_dma_sg {
+       struct ls2x_dma_hw_desc *hw;
+       dma_addr_t              llp;
+       dma_addr_t              phys;
+       u32                     len;
+};
+
+/*
+ * struct ls2x_dma_desc - software descriptor
+ * @vdesc: pointer to the virtual dma descriptor.
+ * @cyclic: flag to dma cyclic
+ * @burst_size: burst size of transaction, in words.
+ * @desc_num: number of sg entries.
+ * @direction: transfer direction, to or from device.
+ * @status: dma controller status.
+ * @sg: array of sgs.
+ */
+struct ls2x_dma_desc {
+       struct virt_dma_desc            vdesc;
+       bool                            cyclic;
+       size_t                          burst_size;
+       u32                             desc_num;
+       enum dma_transfer_direction     direction;
+       enum dma_status                 status;
+       struct ls2x_dma_sg              sg[] __counted_by(desc_num);
+};
+
+/*--  Channels  --------------------------------------------------------*/
+
+/*
+ * struct ls2x_dma_chan - internal representation of an LS2X APB DMA channel
+ * @vchan: virtual dma channel entry.
+ * @desc: pointer to the ls2x sw dma descriptor.
+ * @pool: hw desc table
+ * @irq: irq line
+ * @sconfig: configuration for slave transfers, passed via .device_config
+ */
+struct ls2x_dma_chan {
+       struct virt_dma_chan    vchan;
+       struct ls2x_dma_desc    *desc;
+       void                    *pool;
+       int                     irq;
+       struct dma_slave_config sconfig;
+};
+
+/*--  Controller  ------------------------------------------------------*/
+
+/*
+ * struct ls2x_dma_priv - LS2X APB DMAC specific information
+ * @ddev: dmaengine dma_device object members
+ * @dma_clk: DMAC clock source
+ * @regs: memory mapped register base
+ * @lchan: channel to store ls2x_dma_chan structures
+ */
+struct ls2x_dma_priv {
+       struct dma_device       ddev;
+       struct clk              *dma_clk;
+       void __iomem            *regs;
+       struct ls2x_dma_chan    lchan;
+};
+
+/*--  Helper functions  ------------------------------------------------*/
+
+static inline struct ls2x_dma_desc *to_ldma_desc(struct virt_dma_desc *vdesc)
+{
+       return container_of(vdesc, struct ls2x_dma_desc, vdesc);
+}
+
+static inline struct ls2x_dma_chan *to_ldma_chan(struct dma_chan *chan)
+{
+       return container_of(chan, struct ls2x_dma_chan, vchan.chan);
+}
+
+static inline struct ls2x_dma_priv *to_ldma_priv(struct dma_device *ddev)
+{
+       return container_of(ddev, struct ls2x_dma_priv, ddev);
+}
+
+static struct device *chan2dev(struct dma_chan *chan)
+{
+       return &chan->dev->device;
+}
+
+static void ls2x_dma_desc_free(struct virt_dma_desc *vdesc)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(vdesc->tx.chan);
+       struct ls2x_dma_desc *desc = to_ldma_desc(vdesc);
+       int i;
+
+       for (i = 0; i < desc->desc_num; i++) {
+               if (desc->sg[i].hw)
+                       dma_pool_free(lchan->pool, desc->sg[i].hw,
+                                     desc->sg[i].llp);
+       }
+
+       kfree(desc);
+}
+
+static void ls2x_dma_write_cmd(struct ls2x_dma_chan *lchan, bool cmd)
+{
+       struct ls2x_dma_priv *priv = to_ldma_priv(lchan->vchan.chan.device);
+       u64 val;
+
+       val = lo_hi_readq(priv->regs + LDMA_ORDER_ERG) & ~LDMA_CONFIG_MASK;
+       val |= LDMA_64BIT_EN | cmd;
+       lo_hi_writeq(val, priv->regs + LDMA_ORDER_ERG);
+}
+
+static void ls2x_dma_start_transfer(struct ls2x_dma_chan *lchan)
+{
+       struct ls2x_dma_priv *priv = to_ldma_priv(lchan->vchan.chan.device);
+       struct ls2x_dma_sg *ldma_sg;
+       struct virt_dma_desc *vdesc;
+       u64 val;
+
+       /* Get the next descriptor */
+       vdesc = vchan_next_desc(&lchan->vchan);
+       if (!vdesc) {
+               lchan->desc = NULL;
+               return;
+       }
+
+       list_del(&vdesc->node);
+       lchan->desc = to_ldma_desc(vdesc);
+       ldma_sg = &lchan->desc->sg[0];
+
+       /* Start DMA */
+       lo_hi_writeq(0, priv->regs + LDMA_ORDER_ERG);
+       val = (ldma_sg->llp & ~LDMA_CONFIG_MASK) | LDMA_64BIT_EN | LDMA_START;
+       lo_hi_writeq(val, priv->regs + LDMA_ORDER_ERG);
+}
+
+static size_t ls2x_dmac_detect_burst(struct ls2x_dma_chan *lchan)
+{
+       u32 maxburst, buswidth;
+
+       /* Reject definitely invalid configurations */
+       if ((lchan->sconfig.src_addr_width & LDMA_SLAVE_BUSWIDTHS) &&
+           (lchan->sconfig.dst_addr_width & LDMA_SLAVE_BUSWIDTHS))
+               return 0;
+
+       if (lchan->sconfig.direction == DMA_MEM_TO_DEV) {
+               maxburst = lchan->sconfig.dst_maxburst;
+               buswidth = lchan->sconfig.dst_addr_width;
+       } else {
+               maxburst = lchan->sconfig.src_maxburst;
+               buswidth = lchan->sconfig.src_addr_width;
+       }
+
+       /* If maxburst is zero, fallback to LDMA_MAX_TRANS_LEN */
+       return maxburst ? (maxburst * buswidth) >> 2 : LDMA_MAX_TRANS_LEN;
+}
+
+static void ls2x_dma_fill_desc(struct ls2x_dma_chan *lchan, u32 sg_index,
+                              struct ls2x_dma_desc *desc)
+{
+       struct ls2x_dma_sg *ldma_sg = &desc->sg[sg_index];
+       u32 num_segments, segment_size;
+
+       if (desc->direction == DMA_MEM_TO_DEV) {
+               ldma_sg->hw->cmd = LDMA_INT | LDMA_DATA_DIRECTION;
+               ldma_sg->hw->apb_addr = lchan->sconfig.dst_addr;
+       } else {
+               ldma_sg->hw->cmd = LDMA_INT;
+               ldma_sg->hw->apb_addr = lchan->sconfig.src_addr;
+       }
+
+       ldma_sg->hw->mem_addr = lower_32_bits(ldma_sg->phys);
+       ldma_sg->hw->high_mem_addr = upper_32_bits(ldma_sg->phys);
+
+       /* Split into multiple equally sized segments if necessary */
+       num_segments = DIV_ROUND_UP((ldma_sg->len + 3) >> 2, desc->burst_size);
+       segment_size = DIV_ROUND_UP((ldma_sg->len + 3) >> 2, num_segments);
+
+       /* Word count register takes input in words */
+       ldma_sg->hw->len = segment_size;
+       ldma_sg->hw->step_times = num_segments;
+       ldma_sg->hw->step_len = 0;
+
+       /* lets make a link list */
+       if (sg_index) {
+               desc->sg[sg_index - 1].hw->ndesc_addr = ldma_sg->llp | LDMA_DESC_EN;
+               desc->sg[sg_index - 1].hw->high_ndesc_addr = upper_32_bits(ldma_sg->llp);
+       }
+}
+
+/*--  DMA Engine API  --------------------------------------------------*/
+
+/*
+ * ls2x_dma_alloc_chan_resources - allocate resources for DMA channel
+ * @chan: allocate descriptor resources for this channel
+ *
+ * return - the number of allocated descriptors
+ */
+static int ls2x_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+
+       /* Create a pool of consistent memory blocks for hardware descriptors */
+       lchan->pool = dma_pool_create(dev_name(chan2dev(chan)),
+                                     chan->device->dev, PAGE_SIZE,
+                                     __alignof__(struct ls2x_dma_hw_desc), 0);
+       if (!lchan->pool) {
+               dev_err(chan2dev(chan), "No memory for descriptors\n");
+               return -ENOMEM;
+       }
+
+       return 1;
+}
+
+/*
+ * ls2x_dma_free_chan_resources - free all channel resources
+ * @chan: DMA channel
+ */
+static void ls2x_dma_free_chan_resources(struct dma_chan *chan)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+
+       vchan_free_chan_resources(to_virt_chan(chan));
+       dma_pool_destroy(lchan->pool);
+       lchan->pool = NULL;
+}
+
+/*
+ * ls2x_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
+ * @chan: DMA channel
+ * @sgl: scatterlist to transfer to/from
+ * @sg_len: number of entries in @scatterlist
+ * @direction: DMA direction
+ * @flags: tx descriptor status flags
+ * @context: transaction context (ignored)
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *
+ls2x_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+                      u32 sg_len, enum dma_transfer_direction direction,
+                      unsigned long flags, void *context)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+       struct ls2x_dma_desc *desc;
+       struct scatterlist *sg;
+       size_t burst_size;
+       int i;
+
+       if (unlikely(!sg_len || !is_slave_direction(direction)))
+               return NULL;
+
+       burst_size = ls2x_dmac_detect_burst(lchan);
+       if (!burst_size)
+               return NULL;
+
+       desc = kzalloc(struct_size(desc, sg, sg_len), GFP_NOWAIT);
+       if (!desc)
+               return NULL;
+
+       desc->desc_num = sg_len;
+       desc->direction = direction;
+       desc->burst_size = burst_size;
+
+       for_each_sg(sgl, sg, sg_len, i) {
+               struct ls2x_dma_sg *ldma_sg = &desc->sg[i];
+
+               /* Allocate DMA capable memory for hardware descriptor */
+               ldma_sg->hw = dma_pool_alloc(lchan->pool, GFP_NOWAIT, &ldma_sg->llp);
+               if (!ldma_sg->hw) {
+                       desc->desc_num = i;
+                       ls2x_dma_desc_free(&desc->vdesc);
+                       return NULL;
+               }
+
+               ldma_sg->phys = sg_dma_address(sg);
+               ldma_sg->len = sg_dma_len(sg);
+
+               ls2x_dma_fill_desc(lchan, i, desc);
+       }
+
+       /* Setting the last descriptor enable bit */
+       desc->sg[sg_len - 1].hw->ndesc_addr &= ~LDMA_DESC_EN;
+       desc->status = DMA_IN_PROGRESS;
+
+       return vchan_tx_prep(&lchan->vchan, &desc->vdesc, flags);
+}
+
+/*
+ * ls2x_dma_prep_dma_cyclic - prepare the cyclic DMA transfer
+ * @chan: the DMA channel to prepare
+ * @buf_addr: physical DMA address where the buffer starts
+ * @buf_len: total number of bytes for the entire buffer
+ * @period_len: number of bytes for each period
+ * @direction: transfer direction, to or from device
+ * @flags: tx descriptor status flags
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *
+ls2x_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+                        size_t period_len, enum dma_transfer_direction direction,
+                        unsigned long flags)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+       struct ls2x_dma_desc *desc;
+       size_t burst_size;
+       u32 num_periods;
+       int i;
+
+       if (unlikely(!buf_len || !period_len))
+               return NULL;
+
+       if (unlikely(!is_slave_direction(direction)))
+               return NULL;
+
+       burst_size = ls2x_dmac_detect_burst(lchan);
+       if (!burst_size)
+               return NULL;
+
+       num_periods = buf_len / period_len;
+       desc = kzalloc(struct_size(desc, sg, num_periods), GFP_NOWAIT);
+       if (!desc)
+               return NULL;
+
+       desc->desc_num = num_periods;
+       desc->direction = direction;
+       desc->burst_size = burst_size;
+
+       /* Build cyclic linked list */
+       for (i = 0; i < num_periods; i++) {
+               struct ls2x_dma_sg *ldma_sg = &desc->sg[i];
+
+               /* Allocate DMA capable memory for hardware descriptor */
+               ldma_sg->hw = dma_pool_alloc(lchan->pool, GFP_NOWAIT, &ldma_sg->llp);
+               if (!ldma_sg->hw) {
+                       desc->desc_num = i;
+                       ls2x_dma_desc_free(&desc->vdesc);
+                       return NULL;
+               }
+
+               ldma_sg->phys = buf_addr + period_len * i;
+               ldma_sg->len = period_len;
+
+               ls2x_dma_fill_desc(lchan, i, desc);
+       }
+
+       /* Lets make a cyclic list */
+       desc->sg[num_periods - 1].hw->ndesc_addr = desc->sg[0].llp | LDMA_DESC_EN;
+       desc->sg[num_periods - 1].hw->high_ndesc_addr = upper_32_bits(desc->sg[0].llp);
+       desc->cyclic = true;
+       desc->status = DMA_IN_PROGRESS;
+
+       return vchan_tx_prep(&lchan->vchan, &desc->vdesc, flags);
+}
+
+/*
+ * ls2x_slave_config - set slave configuration for channel
+ * @chan: dma channel
+ * @cfg: slave configuration
+ *
+ * Sets slave configuration for channel
+ */
+static int ls2x_dma_slave_config(struct dma_chan *chan,
+                                struct dma_slave_config *config)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+
+       memcpy(&lchan->sconfig, config, sizeof(*config));
+       return 0;
+}
+
+/*
+ * ls2x_dma_issue_pending - push pending transactions to the hardware
+ * @chan: channel
+ *
+ * When this function is called, all pending transactions are pushed to the
+ * hardware and executed.
+ */
+static void ls2x_dma_issue_pending(struct dma_chan *chan)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+       unsigned long flags;
+
+       spin_lock_irqsave(&lchan->vchan.lock, flags);
+       if (vchan_issue_pending(&lchan->vchan) && !lchan->desc)
+               ls2x_dma_start_transfer(lchan);
+       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
+}
+
+/*
+ * ls2x_dma_terminate_all - terminate all transactions
+ * @chan: channel
+ *
+ * Stops all DMA transactions.
+ */
+static int ls2x_dma_terminate_all(struct dma_chan *chan)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+       unsigned long flags;
+       LIST_HEAD(head);
+
+       spin_lock_irqsave(&lchan->vchan.lock, flags);
+       /* Setting stop cmd */
+       ls2x_dma_write_cmd(lchan, LDMA_STOP);
+       if (lchan->desc) {
+               vchan_terminate_vdesc(&lchan->desc->vdesc);
+               lchan->desc = NULL;
+       }
+
+       vchan_get_all_descriptors(&lchan->vchan, &head);
+       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
+
+       vchan_dma_desc_free_list(&lchan->vchan, &head);
+       return 0;
+}
+
+/*
+ * ls2x_dma_synchronize - Synchronizes the termination of transfers to the
+ * current context.
+ * @chan: channel
+ */
+static void ls2x_dma_synchronize(struct dma_chan *chan)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+
+       vchan_synchronize(&lchan->vchan);
+}
+
+static int ls2x_dma_pause(struct dma_chan *chan)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+       unsigned long flags;
+
+       spin_lock_irqsave(&lchan->vchan.lock, flags);
+       if (lchan->desc && lchan->desc->status == DMA_IN_PROGRESS) {
+               ls2x_dma_write_cmd(lchan, LDMA_STOP);
+               lchan->desc->status = DMA_PAUSED;
+       }
+       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
+
+       return 0;
+}
+
+static int ls2x_dma_resume(struct dma_chan *chan)
+{
+       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
+       unsigned long flags;
+
+       spin_lock_irqsave(&lchan->vchan.lock, flags);
+       if (lchan->desc && lchan->desc->status == DMA_PAUSED) {
+               lchan->desc->status = DMA_IN_PROGRESS;
+               ls2x_dma_write_cmd(lchan, LDMA_START);
+       }
+       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
+
+       return 0;
+}
+
+/*
+ * ls2x_dma_isr - LS2X DMA Interrupt handler
+ * @irq: IRQ number
+ * @dev_id: Pointer to ls2x_dma_chan
+ *
+ * Return: IRQ_HANDLED/IRQ_NONE
+ */
+static irqreturn_t ls2x_dma_isr(int irq, void *dev_id)
+{
+       struct ls2x_dma_chan *lchan = dev_id;
+       struct ls2x_dma_desc *desc;
+
+       spin_lock(&lchan->vchan.lock);
+       desc = lchan->desc;
+       if (desc) {
+               if (desc->cyclic) {
+                       vchan_cyclic_callback(&desc->vdesc);
+               } else {
+                       desc->status = DMA_COMPLETE;
+                       vchan_cookie_complete(&desc->vdesc);
+                       ls2x_dma_start_transfer(lchan);
+               }
+
+               /* ls2x_dma_start_transfer() updates lchan->desc */
+               if (!lchan->desc)
+                       ls2x_dma_write_cmd(lchan, LDMA_STOP);
+       }
+       spin_unlock(&lchan->vchan.lock);
+
+       return IRQ_HANDLED;
+}
+
+static int ls2x_dma_chan_init(struct platform_device *pdev,
+                             struct ls2x_dma_priv *priv)
+{
+       struct ls2x_dma_chan *lchan = &priv->lchan;
+       struct device *dev = &pdev->dev;
+       int ret;
+
+       lchan->irq = platform_get_irq(pdev, 0);
+       if (lchan->irq < 0)
+               return lchan->irq;
+
+       ret = devm_request_irq(dev, lchan->irq, ls2x_dma_isr, IRQF_TRIGGER_RISING,
+                              dev_name(&pdev->dev), lchan);
+       if (ret)
+               return ret;
+
+       /* Initialize channels related values */
+       INIT_LIST_HEAD(&priv->ddev.channels);
+       lchan->vchan.desc_free = ls2x_dma_desc_free;
+       vchan_init(&lchan->vchan, &priv->ddev);
+
+       return 0;
+}
+
+/*
+ * ls2x_dma_probe - Driver probe function
+ * @pdev: Pointer to the platform_device structure
+ *
+ * Return: '0' on success and failure value on error
+ */
+static int ls2x_dma_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct ls2x_dma_priv *priv;
+       struct dma_device *ddev;
+       int ret;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       priv->regs = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(priv->regs))
+               return dev_err_probe(dev, PTR_ERR(priv->regs),
+                                    "devm_platform_ioremap_resource failed.\n");
+
+       priv->dma_clk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(priv->dma_clk))
+               return dev_err_probe(dev, PTR_ERR(priv->dma_clk), "devm_clk_get failed.\n");
+
+       ret = clk_prepare_enable(priv->dma_clk);
+       if (ret)
+               return dev_err_probe(dev, ret, "clk_prepare_enable failed.\n");
+
+       ret = ls2x_dma_chan_init(pdev, priv);
+       if (ret)
+               goto disable_clk;
+
+       ddev = &priv->ddev;
+       ddev->dev = dev;
+       dma_cap_zero(ddev->cap_mask);
+       dma_cap_set(DMA_SLAVE, ddev->cap_mask);
+       dma_cap_set(DMA_CYCLIC, ddev->cap_mask);
+
+       ddev->device_alloc_chan_resources = ls2x_dma_alloc_chan_resources;
+       ddev->device_free_chan_resources = ls2x_dma_free_chan_resources;
+       ddev->device_tx_status = dma_cookie_status;
+       ddev->device_issue_pending = ls2x_dma_issue_pending;
+       ddev->device_prep_slave_sg = ls2x_dma_prep_slave_sg;
+       ddev->device_prep_dma_cyclic = ls2x_dma_prep_dma_cyclic;
+       ddev->device_config = ls2x_dma_slave_config;
+       ddev->device_terminate_all = ls2x_dma_terminate_all;
+       ddev->device_synchronize = ls2x_dma_synchronize;
+       ddev->device_pause = ls2x_dma_pause;
+       ddev->device_resume = ls2x_dma_resume;
+
+       ddev->src_addr_widths = LDMA_SLAVE_BUSWIDTHS;
+       ddev->dst_addr_widths = LDMA_SLAVE_BUSWIDTHS;
+       ddev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+
+       ret = dma_async_device_register(&priv->ddev);
+       if (ret < 0)
+               goto disable_clk;
+
+       ret = of_dma_controller_register(dev->of_node, of_dma_xlate_by_chan_id, priv);
+       if (ret < 0)
+               goto unregister_dmac;
+
+       platform_set_drvdata(pdev, priv);
+
+       dev_info(dev, "Loongson LS2X APB DMA driver registered successfully.\n");
+       return 0;
+
+unregister_dmac:
+       dma_async_device_unregister(&priv->ddev);
+disable_clk:
+       clk_disable_unprepare(priv->dma_clk);
+
+       return ret;
+}
+
+/*
+ * ls2x_dma_remove - Driver remove function
+ * @pdev: Pointer to the platform_device structure
+ */
+static void ls2x_dma_remove(struct platform_device *pdev)
+{
+       struct ls2x_dma_priv *priv = platform_get_drvdata(pdev);
+
+       of_dma_controller_free(pdev->dev.of_node);
+       dma_async_device_unregister(&priv->ddev);
+       clk_disable_unprepare(priv->dma_clk);
+}
+
+static const struct of_device_id ls2x_dma_of_match_table[] = {
+       { .compatible = "loongson,ls2k1000-apbdma" },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ls2x_dma_of_match_table);
+
+static struct platform_driver ls2x_dmac_driver = {
+       .probe          = ls2x_dma_probe,
+       .remove         = ls2x_dma_remove,
+       .driver = {
+               .name   = "ls2x-apbdma",
+               .of_match_table = ls2x_dma_of_match_table,
+       },
+};
+module_platform_driver(ls2x_dmac_driver);
+
+MODULE_DESCRIPTION("Loongson-2 APB DMA Controller driver");
+MODULE_AUTHOR("Loongson Technology Corporation Limited");
+MODULE_LICENSE("GPL");
diff --git a/drivers/dma/ls2x-apb-dma.c b/drivers/dma/ls2x-apb-dma.c
deleted file mode 100644 (file)
index 2460cf9..0000000
+++ /dev/null
@@ -1,705 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Driver for the Loongson LS2X APB DMA Controller
- *
- * Copyright (C) 2017-2023 Loongson Corporation
- */
-
-#include <linux/clk.h>
-#include <linux/dma-mapping.h>
-#include <linux/dmapool.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-#include <linux/io-64-nonatomic-lo-hi.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/of_dma.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-
-#include "dmaengine.h"
-#include "virt-dma.h"
-
-/* Global Configuration Register */
-#define LDMA_ORDER_ERG         0x0
-
-/* Bitfield definitions */
-
-/* Bitfields in Global Configuration Register */
-#define LDMA_64BIT_EN          BIT(0) /* 1: 64 bit support */
-#define LDMA_UNCOHERENT_EN     BIT(1) /* 0: cache, 1: uncache */
-#define LDMA_ASK_VALID         BIT(2)
-#define LDMA_START             BIT(3) /* DMA start operation */
-#define LDMA_STOP              BIT(4) /* DMA stop operation */
-#define LDMA_CONFIG_MASK       GENMASK(4, 0) /* DMA controller config bits mask */
-
-/* Bitfields in ndesc_addr field of HW descriptor */
-#define LDMA_DESC_EN           BIT(0) /*1: The next descriptor is valid */
-#define LDMA_DESC_ADDR_LOW     GENMASK(31, 1)
-
-/* Bitfields in cmd field of HW descriptor */
-#define LDMA_INT               BIT(1) /* Enable DMA interrupts */
-#define LDMA_DATA_DIRECTION    BIT(12) /* 1: write to device, 0: read from device */
-
-#define LDMA_SLAVE_BUSWIDTHS   (BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
-                                BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
-
-#define LDMA_MAX_TRANS_LEN     U32_MAX
-
-/*--  descriptors  -----------------------------------------------------*/
-
-/*
- * struct ls2x_dma_hw_desc - DMA HW descriptor
- * @ndesc_addr: the next descriptor low address.
- * @mem_addr: memory low address.
- * @apb_addr: device buffer address.
- * @len: length of a piece of carried content, in words.
- * @step_len: length between two moved memory data blocks.
- * @step_times: number of blocks to be carried in a single DMA operation.
- * @cmd: descriptor command or state.
- * @stats: DMA status.
- * @high_ndesc_addr: the next descriptor high address.
- * @high_mem_addr: memory high address.
- * @reserved: reserved
- */
-struct ls2x_dma_hw_desc {
-       u32 ndesc_addr;
-       u32 mem_addr;
-       u32 apb_addr;
-       u32 len;
-       u32 step_len;
-       u32 step_times;
-       u32 cmd;
-       u32 stats;
-       u32 high_ndesc_addr;
-       u32 high_mem_addr;
-       u32 reserved[2];
-} __packed;
-
-/*
- * struct ls2x_dma_sg - ls2x dma scatter gather entry
- * @hw: the pointer to DMA HW descriptor.
- * @llp: physical address of the DMA HW descriptor.
- * @phys: destination or source address(mem).
- * @len: number of Bytes to read.
- */
-struct ls2x_dma_sg {
-       struct ls2x_dma_hw_desc *hw;
-       dma_addr_t              llp;
-       dma_addr_t              phys;
-       u32                     len;
-};
-
-/*
- * struct ls2x_dma_desc - software descriptor
- * @vdesc: pointer to the virtual dma descriptor.
- * @cyclic: flag to dma cyclic
- * @burst_size: burst size of transaction, in words.
- * @desc_num: number of sg entries.
- * @direction: transfer direction, to or from device.
- * @status: dma controller status.
- * @sg: array of sgs.
- */
-struct ls2x_dma_desc {
-       struct virt_dma_desc            vdesc;
-       bool                            cyclic;
-       size_t                          burst_size;
-       u32                             desc_num;
-       enum dma_transfer_direction     direction;
-       enum dma_status                 status;
-       struct ls2x_dma_sg              sg[] __counted_by(desc_num);
-};
-
-/*--  Channels  --------------------------------------------------------*/
-
-/*
- * struct ls2x_dma_chan - internal representation of an LS2X APB DMA channel
- * @vchan: virtual dma channel entry.
- * @desc: pointer to the ls2x sw dma descriptor.
- * @pool: hw desc table
- * @irq: irq line
- * @sconfig: configuration for slave transfers, passed via .device_config
- */
-struct ls2x_dma_chan {
-       struct virt_dma_chan    vchan;
-       struct ls2x_dma_desc    *desc;
-       void                    *pool;
-       int                     irq;
-       struct dma_slave_config sconfig;
-};
-
-/*--  Controller  ------------------------------------------------------*/
-
-/*
- * struct ls2x_dma_priv - LS2X APB DMAC specific information
- * @ddev: dmaengine dma_device object members
- * @dma_clk: DMAC clock source
- * @regs: memory mapped register base
- * @lchan: channel to store ls2x_dma_chan structures
- */
-struct ls2x_dma_priv {
-       struct dma_device       ddev;
-       struct clk              *dma_clk;
-       void __iomem            *regs;
-       struct ls2x_dma_chan    lchan;
-};
-
-/*--  Helper functions  ------------------------------------------------*/
-
-static inline struct ls2x_dma_desc *to_ldma_desc(struct virt_dma_desc *vdesc)
-{
-       return container_of(vdesc, struct ls2x_dma_desc, vdesc);
-}
-
-static inline struct ls2x_dma_chan *to_ldma_chan(struct dma_chan *chan)
-{
-       return container_of(chan, struct ls2x_dma_chan, vchan.chan);
-}
-
-static inline struct ls2x_dma_priv *to_ldma_priv(struct dma_device *ddev)
-{
-       return container_of(ddev, struct ls2x_dma_priv, ddev);
-}
-
-static struct device *chan2dev(struct dma_chan *chan)
-{
-       return &chan->dev->device;
-}
-
-static void ls2x_dma_desc_free(struct virt_dma_desc *vdesc)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(vdesc->tx.chan);
-       struct ls2x_dma_desc *desc = to_ldma_desc(vdesc);
-       int i;
-
-       for (i = 0; i < desc->desc_num; i++) {
-               if (desc->sg[i].hw)
-                       dma_pool_free(lchan->pool, desc->sg[i].hw,
-                                     desc->sg[i].llp);
-       }
-
-       kfree(desc);
-}
-
-static void ls2x_dma_write_cmd(struct ls2x_dma_chan *lchan, bool cmd)
-{
-       struct ls2x_dma_priv *priv = to_ldma_priv(lchan->vchan.chan.device);
-       u64 val;
-
-       val = lo_hi_readq(priv->regs + LDMA_ORDER_ERG) & ~LDMA_CONFIG_MASK;
-       val |= LDMA_64BIT_EN | cmd;
-       lo_hi_writeq(val, priv->regs + LDMA_ORDER_ERG);
-}
-
-static void ls2x_dma_start_transfer(struct ls2x_dma_chan *lchan)
-{
-       struct ls2x_dma_priv *priv = to_ldma_priv(lchan->vchan.chan.device);
-       struct ls2x_dma_sg *ldma_sg;
-       struct virt_dma_desc *vdesc;
-       u64 val;
-
-       /* Get the next descriptor */
-       vdesc = vchan_next_desc(&lchan->vchan);
-       if (!vdesc) {
-               lchan->desc = NULL;
-               return;
-       }
-
-       list_del(&vdesc->node);
-       lchan->desc = to_ldma_desc(vdesc);
-       ldma_sg = &lchan->desc->sg[0];
-
-       /* Start DMA */
-       lo_hi_writeq(0, priv->regs + LDMA_ORDER_ERG);
-       val = (ldma_sg->llp & ~LDMA_CONFIG_MASK) | LDMA_64BIT_EN | LDMA_START;
-       lo_hi_writeq(val, priv->regs + LDMA_ORDER_ERG);
-}
-
-static size_t ls2x_dmac_detect_burst(struct ls2x_dma_chan *lchan)
-{
-       u32 maxburst, buswidth;
-
-       /* Reject definitely invalid configurations */
-       if ((lchan->sconfig.src_addr_width & LDMA_SLAVE_BUSWIDTHS) &&
-           (lchan->sconfig.dst_addr_width & LDMA_SLAVE_BUSWIDTHS))
-               return 0;
-
-       if (lchan->sconfig.direction == DMA_MEM_TO_DEV) {
-               maxburst = lchan->sconfig.dst_maxburst;
-               buswidth = lchan->sconfig.dst_addr_width;
-       } else {
-               maxburst = lchan->sconfig.src_maxburst;
-               buswidth = lchan->sconfig.src_addr_width;
-       }
-
-       /* If maxburst is zero, fallback to LDMA_MAX_TRANS_LEN */
-       return maxburst ? (maxburst * buswidth) >> 2 : LDMA_MAX_TRANS_LEN;
-}
-
-static void ls2x_dma_fill_desc(struct ls2x_dma_chan *lchan, u32 sg_index,
-                              struct ls2x_dma_desc *desc)
-{
-       struct ls2x_dma_sg *ldma_sg = &desc->sg[sg_index];
-       u32 num_segments, segment_size;
-
-       if (desc->direction == DMA_MEM_TO_DEV) {
-               ldma_sg->hw->cmd = LDMA_INT | LDMA_DATA_DIRECTION;
-               ldma_sg->hw->apb_addr = lchan->sconfig.dst_addr;
-       } else {
-               ldma_sg->hw->cmd = LDMA_INT;
-               ldma_sg->hw->apb_addr = lchan->sconfig.src_addr;
-       }
-
-       ldma_sg->hw->mem_addr = lower_32_bits(ldma_sg->phys);
-       ldma_sg->hw->high_mem_addr = upper_32_bits(ldma_sg->phys);
-
-       /* Split into multiple equally sized segments if necessary */
-       num_segments = DIV_ROUND_UP((ldma_sg->len + 3) >> 2, desc->burst_size);
-       segment_size = DIV_ROUND_UP((ldma_sg->len + 3) >> 2, num_segments);
-
-       /* Word count register takes input in words */
-       ldma_sg->hw->len = segment_size;
-       ldma_sg->hw->step_times = num_segments;
-       ldma_sg->hw->step_len = 0;
-
-       /* lets make a link list */
-       if (sg_index) {
-               desc->sg[sg_index - 1].hw->ndesc_addr = ldma_sg->llp | LDMA_DESC_EN;
-               desc->sg[sg_index - 1].hw->high_ndesc_addr = upper_32_bits(ldma_sg->llp);
-       }
-}
-
-/*--  DMA Engine API  --------------------------------------------------*/
-
-/*
- * ls2x_dma_alloc_chan_resources - allocate resources for DMA channel
- * @chan: allocate descriptor resources for this channel
- *
- * return - the number of allocated descriptors
- */
-static int ls2x_dma_alloc_chan_resources(struct dma_chan *chan)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-
-       /* Create a pool of consistent memory blocks for hardware descriptors */
-       lchan->pool = dma_pool_create(dev_name(chan2dev(chan)),
-                                     chan->device->dev, PAGE_SIZE,
-                                     __alignof__(struct ls2x_dma_hw_desc), 0);
-       if (!lchan->pool) {
-               dev_err(chan2dev(chan), "No memory for descriptors\n");
-               return -ENOMEM;
-       }
-
-       return 1;
-}
-
-/*
- * ls2x_dma_free_chan_resources - free all channel resources
- * @chan: DMA channel
- */
-static void ls2x_dma_free_chan_resources(struct dma_chan *chan)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-
-       vchan_free_chan_resources(to_virt_chan(chan));
-       dma_pool_destroy(lchan->pool);
-       lchan->pool = NULL;
-}
-
-/*
- * ls2x_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
- * @chan: DMA channel
- * @sgl: scatterlist to transfer to/from
- * @sg_len: number of entries in @scatterlist
- * @direction: DMA direction
- * @flags: tx descriptor status flags
- * @context: transaction context (ignored)
- *
- * Return: Async transaction descriptor on success and NULL on failure
- */
-static struct dma_async_tx_descriptor *
-ls2x_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
-                      u32 sg_len, enum dma_transfer_direction direction,
-                      unsigned long flags, void *context)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-       struct ls2x_dma_desc *desc;
-       struct scatterlist *sg;
-       size_t burst_size;
-       int i;
-
-       if (unlikely(!sg_len || !is_slave_direction(direction)))
-               return NULL;
-
-       burst_size = ls2x_dmac_detect_burst(lchan);
-       if (!burst_size)
-               return NULL;
-
-       desc = kzalloc(struct_size(desc, sg, sg_len), GFP_NOWAIT);
-       if (!desc)
-               return NULL;
-
-       desc->desc_num = sg_len;
-       desc->direction = direction;
-       desc->burst_size = burst_size;
-
-       for_each_sg(sgl, sg, sg_len, i) {
-               struct ls2x_dma_sg *ldma_sg = &desc->sg[i];
-
-               /* Allocate DMA capable memory for hardware descriptor */
-               ldma_sg->hw = dma_pool_alloc(lchan->pool, GFP_NOWAIT, &ldma_sg->llp);
-               if (!ldma_sg->hw) {
-                       desc->desc_num = i;
-                       ls2x_dma_desc_free(&desc->vdesc);
-                       return NULL;
-               }
-
-               ldma_sg->phys = sg_dma_address(sg);
-               ldma_sg->len = sg_dma_len(sg);
-
-               ls2x_dma_fill_desc(lchan, i, desc);
-       }
-
-       /* Setting the last descriptor enable bit */
-       desc->sg[sg_len - 1].hw->ndesc_addr &= ~LDMA_DESC_EN;
-       desc->status = DMA_IN_PROGRESS;
-
-       return vchan_tx_prep(&lchan->vchan, &desc->vdesc, flags);
-}
-
-/*
- * ls2x_dma_prep_dma_cyclic - prepare the cyclic DMA transfer
- * @chan: the DMA channel to prepare
- * @buf_addr: physical DMA address where the buffer starts
- * @buf_len: total number of bytes for the entire buffer
- * @period_len: number of bytes for each period
- * @direction: transfer direction, to or from device
- * @flags: tx descriptor status flags
- *
- * Return: Async transaction descriptor on success and NULL on failure
- */
-static struct dma_async_tx_descriptor *
-ls2x_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
-                        size_t period_len, enum dma_transfer_direction direction,
-                        unsigned long flags)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-       struct ls2x_dma_desc *desc;
-       size_t burst_size;
-       u32 num_periods;
-       int i;
-
-       if (unlikely(!buf_len || !period_len))
-               return NULL;
-
-       if (unlikely(!is_slave_direction(direction)))
-               return NULL;
-
-       burst_size = ls2x_dmac_detect_burst(lchan);
-       if (!burst_size)
-               return NULL;
-
-       num_periods = buf_len / period_len;
-       desc = kzalloc(struct_size(desc, sg, num_periods), GFP_NOWAIT);
-       if (!desc)
-               return NULL;
-
-       desc->desc_num = num_periods;
-       desc->direction = direction;
-       desc->burst_size = burst_size;
-
-       /* Build cyclic linked list */
-       for (i = 0; i < num_periods; i++) {
-               struct ls2x_dma_sg *ldma_sg = &desc->sg[i];
-
-               /* Allocate DMA capable memory for hardware descriptor */
-               ldma_sg->hw = dma_pool_alloc(lchan->pool, GFP_NOWAIT, &ldma_sg->llp);
-               if (!ldma_sg->hw) {
-                       desc->desc_num = i;
-                       ls2x_dma_desc_free(&desc->vdesc);
-                       return NULL;
-               }
-
-               ldma_sg->phys = buf_addr + period_len * i;
-               ldma_sg->len = period_len;
-
-               ls2x_dma_fill_desc(lchan, i, desc);
-       }
-
-       /* Lets make a cyclic list */
-       desc->sg[num_periods - 1].hw->ndesc_addr = desc->sg[0].llp | LDMA_DESC_EN;
-       desc->sg[num_periods - 1].hw->high_ndesc_addr = upper_32_bits(desc->sg[0].llp);
-       desc->cyclic = true;
-       desc->status = DMA_IN_PROGRESS;
-
-       return vchan_tx_prep(&lchan->vchan, &desc->vdesc, flags);
-}
-
-/*
- * ls2x_slave_config - set slave configuration for channel
- * @chan: dma channel
- * @cfg: slave configuration
- *
- * Sets slave configuration for channel
- */
-static int ls2x_dma_slave_config(struct dma_chan *chan,
-                                struct dma_slave_config *config)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-
-       memcpy(&lchan->sconfig, config, sizeof(*config));
-       return 0;
-}
-
-/*
- * ls2x_dma_issue_pending - push pending transactions to the hardware
- * @chan: channel
- *
- * When this function is called, all pending transactions are pushed to the
- * hardware and executed.
- */
-static void ls2x_dma_issue_pending(struct dma_chan *chan)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-       unsigned long flags;
-
-       spin_lock_irqsave(&lchan->vchan.lock, flags);
-       if (vchan_issue_pending(&lchan->vchan) && !lchan->desc)
-               ls2x_dma_start_transfer(lchan);
-       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
-}
-
-/*
- * ls2x_dma_terminate_all - terminate all transactions
- * @chan: channel
- *
- * Stops all DMA transactions.
- */
-static int ls2x_dma_terminate_all(struct dma_chan *chan)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-       unsigned long flags;
-       LIST_HEAD(head);
-
-       spin_lock_irqsave(&lchan->vchan.lock, flags);
-       /* Setting stop cmd */
-       ls2x_dma_write_cmd(lchan, LDMA_STOP);
-       if (lchan->desc) {
-               vchan_terminate_vdesc(&lchan->desc->vdesc);
-               lchan->desc = NULL;
-       }
-
-       vchan_get_all_descriptors(&lchan->vchan, &head);
-       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
-
-       vchan_dma_desc_free_list(&lchan->vchan, &head);
-       return 0;
-}
-
-/*
- * ls2x_dma_synchronize - Synchronizes the termination of transfers to the
- * current context.
- * @chan: channel
- */
-static void ls2x_dma_synchronize(struct dma_chan *chan)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-
-       vchan_synchronize(&lchan->vchan);
-}
-
-static int ls2x_dma_pause(struct dma_chan *chan)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-       unsigned long flags;
-
-       spin_lock_irqsave(&lchan->vchan.lock, flags);
-       if (lchan->desc && lchan->desc->status == DMA_IN_PROGRESS) {
-               ls2x_dma_write_cmd(lchan, LDMA_STOP);
-               lchan->desc->status = DMA_PAUSED;
-       }
-       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
-
-       return 0;
-}
-
-static int ls2x_dma_resume(struct dma_chan *chan)
-{
-       struct ls2x_dma_chan *lchan = to_ldma_chan(chan);
-       unsigned long flags;
-
-       spin_lock_irqsave(&lchan->vchan.lock, flags);
-       if (lchan->desc && lchan->desc->status == DMA_PAUSED) {
-               lchan->desc->status = DMA_IN_PROGRESS;
-               ls2x_dma_write_cmd(lchan, LDMA_START);
-       }
-       spin_unlock_irqrestore(&lchan->vchan.lock, flags);
-
-       return 0;
-}
-
-/*
- * ls2x_dma_isr - LS2X DMA Interrupt handler
- * @irq: IRQ number
- * @dev_id: Pointer to ls2x_dma_chan
- *
- * Return: IRQ_HANDLED/IRQ_NONE
- */
-static irqreturn_t ls2x_dma_isr(int irq, void *dev_id)
-{
-       struct ls2x_dma_chan *lchan = dev_id;
-       struct ls2x_dma_desc *desc;
-
-       spin_lock(&lchan->vchan.lock);
-       desc = lchan->desc;
-       if (desc) {
-               if (desc->cyclic) {
-                       vchan_cyclic_callback(&desc->vdesc);
-               } else {
-                       desc->status = DMA_COMPLETE;
-                       vchan_cookie_complete(&desc->vdesc);
-                       ls2x_dma_start_transfer(lchan);
-               }
-
-               /* ls2x_dma_start_transfer() updates lchan->desc */
-               if (!lchan->desc)
-                       ls2x_dma_write_cmd(lchan, LDMA_STOP);
-       }
-       spin_unlock(&lchan->vchan.lock);
-
-       return IRQ_HANDLED;
-}
-
-static int ls2x_dma_chan_init(struct platform_device *pdev,
-                             struct ls2x_dma_priv *priv)
-{
-       struct ls2x_dma_chan *lchan = &priv->lchan;
-       struct device *dev = &pdev->dev;
-       int ret;
-
-       lchan->irq = platform_get_irq(pdev, 0);
-       if (lchan->irq < 0)
-               return lchan->irq;
-
-       ret = devm_request_irq(dev, lchan->irq, ls2x_dma_isr, IRQF_TRIGGER_RISING,
-                              dev_name(&pdev->dev), lchan);
-       if (ret)
-               return ret;
-
-       /* Initialize channels related values */
-       INIT_LIST_HEAD(&priv->ddev.channels);
-       lchan->vchan.desc_free = ls2x_dma_desc_free;
-       vchan_init(&lchan->vchan, &priv->ddev);
-
-       return 0;
-}
-
-/*
- * ls2x_dma_probe - Driver probe function
- * @pdev: Pointer to the platform_device structure
- *
- * Return: '0' on success and failure value on error
- */
-static int ls2x_dma_probe(struct platform_device *pdev)
-{
-       struct device *dev = &pdev->dev;
-       struct ls2x_dma_priv *priv;
-       struct dma_device *ddev;
-       int ret;
-
-       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
-       if (!priv)
-               return -ENOMEM;
-
-       priv->regs = devm_platform_ioremap_resource(pdev, 0);
-       if (IS_ERR(priv->regs))
-               return dev_err_probe(dev, PTR_ERR(priv->regs),
-                                    "devm_platform_ioremap_resource failed.\n");
-
-       priv->dma_clk = devm_clk_get(&pdev->dev, NULL);
-       if (IS_ERR(priv->dma_clk))
-               return dev_err_probe(dev, PTR_ERR(priv->dma_clk), "devm_clk_get failed.\n");
-
-       ret = clk_prepare_enable(priv->dma_clk);
-       if (ret)
-               return dev_err_probe(dev, ret, "clk_prepare_enable failed.\n");
-
-       ret = ls2x_dma_chan_init(pdev, priv);
-       if (ret)
-               goto disable_clk;
-
-       ddev = &priv->ddev;
-       ddev->dev = dev;
-       dma_cap_zero(ddev->cap_mask);
-       dma_cap_set(DMA_SLAVE, ddev->cap_mask);
-       dma_cap_set(DMA_CYCLIC, ddev->cap_mask);
-
-       ddev->device_alloc_chan_resources = ls2x_dma_alloc_chan_resources;
-       ddev->device_free_chan_resources = ls2x_dma_free_chan_resources;
-       ddev->device_tx_status = dma_cookie_status;
-       ddev->device_issue_pending = ls2x_dma_issue_pending;
-       ddev->device_prep_slave_sg = ls2x_dma_prep_slave_sg;
-       ddev->device_prep_dma_cyclic = ls2x_dma_prep_dma_cyclic;
-       ddev->device_config = ls2x_dma_slave_config;
-       ddev->device_terminate_all = ls2x_dma_terminate_all;
-       ddev->device_synchronize = ls2x_dma_synchronize;
-       ddev->device_pause = ls2x_dma_pause;
-       ddev->device_resume = ls2x_dma_resume;
-
-       ddev->src_addr_widths = LDMA_SLAVE_BUSWIDTHS;
-       ddev->dst_addr_widths = LDMA_SLAVE_BUSWIDTHS;
-       ddev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
-
-       ret = dma_async_device_register(&priv->ddev);
-       if (ret < 0)
-               goto disable_clk;
-
-       ret = of_dma_controller_register(dev->of_node, of_dma_xlate_by_chan_id, priv);
-       if (ret < 0)
-               goto unregister_dmac;
-
-       platform_set_drvdata(pdev, priv);
-
-       dev_info(dev, "Loongson LS2X APB DMA driver registered successfully.\n");
-       return 0;
-
-unregister_dmac:
-       dma_async_device_unregister(&priv->ddev);
-disable_clk:
-       clk_disable_unprepare(priv->dma_clk);
-
-       return ret;
-}
-
-/*
- * ls2x_dma_remove - Driver remove function
- * @pdev: Pointer to the platform_device structure
- */
-static void ls2x_dma_remove(struct platform_device *pdev)
-{
-       struct ls2x_dma_priv *priv = platform_get_drvdata(pdev);
-
-       of_dma_controller_free(pdev->dev.of_node);
-       dma_async_device_unregister(&priv->ddev);
-       clk_disable_unprepare(priv->dma_clk);
-}
-
-static const struct of_device_id ls2x_dma_of_match_table[] = {
-       { .compatible = "loongson,ls2k1000-apbdma" },
-       { /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, ls2x_dma_of_match_table);
-
-static struct platform_driver ls2x_dmac_driver = {
-       .probe          = ls2x_dma_probe,
-       .remove         = ls2x_dma_remove,
-       .driver = {
-               .name   = "ls2x-apbdma",
-               .of_match_table = ls2x_dma_of_match_table,
-       },
-};
-module_platform_driver(ls2x_dmac_driver);
-
-MODULE_DESCRIPTION("Loongson LS2X APB DMA Controller driver");
-MODULE_AUTHOR("Loongson Technology Corporation Limited");
-MODULE_LICENSE("GPL");