diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 18:50:36 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 18:50:36 +0000 |
commit | 50ba0232fd5312410f1b65247e774244f89a628e (patch) | |
tree | fd8f2fc78e9e548af0ff9590276602ee6125be00 /drivers/dma/ls2x-apb-dma.c | |
parent | Releasing progress-linux version 6.7.12-1~progress7.99u1. (diff) | |
download | linux-50ba0232fd5312410f1b65247e774244f89a628e.tar.xz linux-50ba0232fd5312410f1b65247e774244f89a628e.zip |
Merging upstream version 6.8.9.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/dma/ls2x-apb-dma.c')
-rw-r--r-- | drivers/dma/ls2x-apb-dma.c | 705 |
1 files changed, 705 insertions, 0 deletions
diff --git a/drivers/dma/ls2x-apb-dma.c b/drivers/dma/ls2x-apb-dma.c new file mode 100644 index 0000000000..a49913f3ed --- /dev/null +++ b/drivers/dma/ls2x-apb-dma.c @@ -0,0 +1,705 @@ +// 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 decriptor */ +#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 decriptor */ +#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_new = 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"); |