Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block

[linux/fpc-iii.git] / drivers / dma / qcom / qcom_adm.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>

#include "../dmaengine.h"
#include "../virt-dma.h"

/* ADM registers - calculated from channel number and security domain */
#define ADM_CHAN_MULTI                  0x4
#define ADM_CI_MULTI                    0x4
#define ADM_CRCI_MULTI                  0x4
#define ADM_EE_MULTI                    0x800
#define ADM_CHAN_OFFS(chan)             (ADM_CHAN_MULTI * (chan))
#define ADM_EE_OFFS(ee)                 (ADM_EE_MULTI * (ee))
#define ADM_CHAN_EE_OFFS(chan, ee)      (ADM_CHAN_OFFS(chan) + ADM_EE_OFFS(ee))
#define ADM_CHAN_OFFS(chan)             (ADM_CHAN_MULTI * (chan))
#define ADM_CI_OFFS(ci)                 (ADM_CHAN_OFF(ci))
#define ADM_CH_CMD_PTR(chan, ee)        (ADM_CHAN_EE_OFFS(chan, ee))
#define ADM_CH_RSLT(chan, ee)           (0x40 + ADM_CHAN_EE_OFFS(chan, ee))
#define ADM_CH_FLUSH_STATE0(chan, ee)   (0x80 + ADM_CHAN_EE_OFFS(chan, ee))
#define ADM_CH_STATUS_SD(chan, ee)      (0x200 + ADM_CHAN_EE_OFFS(chan, ee))
#define ADM_CH_CONF(chan)               (0x240 + ADM_CHAN_OFFS(chan))
#define ADM_CH_RSLT_CONF(chan, ee)      (0x300 + ADM_CHAN_EE_OFFS(chan, ee))
#define ADM_SEC_DOMAIN_IRQ_STATUS(ee)   (0x380 + ADM_EE_OFFS(ee))
#define ADM_CI_CONF(ci)                 (0x390 + (ci) * ADM_CI_MULTI)
#define ADM_GP_CTL                      0x3d8
#define ADM_CRCI_CTL(crci, ee)          (0x400 + (crci) * ADM_CRCI_MULTI + \
                                                ADM_EE_OFFS(ee))

/* channel status */
#define ADM_CH_STATUS_VALID             BIT(1)

/* channel result */
#define ADM_CH_RSLT_VALID               BIT(31)
#define ADM_CH_RSLT_ERR                 BIT(3)
#define ADM_CH_RSLT_FLUSH               BIT(2)
#define ADM_CH_RSLT_TPD                 BIT(1)

/* channel conf */
#define ADM_CH_CONF_SHADOW_EN           BIT(12)
#define ADM_CH_CONF_MPU_DISABLE         BIT(11)
#define ADM_CH_CONF_PERM_MPU_CONF       BIT(9)
#define ADM_CH_CONF_FORCE_RSLT_EN       BIT(7)
#define ADM_CH_CONF_SEC_DOMAIN(ee)      ((((ee) & 0x3) << 4) | (((ee) & 0x4) << 11))

/* channel result conf */
#define ADM_CH_RSLT_CONF_FLUSH_EN       BIT(1)
#define ADM_CH_RSLT_CONF_IRQ_EN         BIT(0)

/* CRCI CTL */
#define ADM_CRCI_CTL_MUX_SEL            BIT(18)
#define ADM_CRCI_CTL_RST                BIT(17)

/* CI configuration */
#define ADM_CI_RANGE_END(x)             ((x) << 24)
#define ADM_CI_RANGE_START(x)           ((x) << 16)
#define ADM_CI_BURST_4_WORDS            BIT(2)
#define ADM_CI_BURST_8_WORDS            BIT(3)

/* GP CTL */
#define ADM_GP_CTL_LP_EN                BIT(12)
#define ADM_GP_CTL_LP_CNT(x)            ((x) << 8)

/* Command pointer list entry */
#define ADM_CPLE_LP                     BIT(31)
#define ADM_CPLE_CMD_PTR_LIST           BIT(29)

/* Command list entry */
#define ADM_CMD_LC                      BIT(31)
#define ADM_CMD_DST_CRCI(n)             (((n) & 0xf) << 7)
#define ADM_CMD_SRC_CRCI(n)             (((n) & 0xf) << 3)

#define ADM_CMD_TYPE_SINGLE             0x0
#define ADM_CMD_TYPE_BOX                0x3

#define ADM_CRCI_MUX_SEL                BIT(4)
#define ADM_DESC_ALIGN                  8
#define ADM_MAX_XFER                    (SZ_64K - 1)
#define ADM_MAX_ROWS                    (SZ_64K - 1)
#define ADM_MAX_CHANNELS                16

struct adm_desc_hw_box {
        u32 cmd;
        u32 src_addr;
        u32 dst_addr;
        u32 row_len;
        u32 num_rows;
        u32 row_offset;
};

struct adm_desc_hw_single {
        u32 cmd;
        u32 src_addr;
        u32 dst_addr;
        u32 len;
};

struct adm_async_desc {
        struct virt_dma_desc vd;
        struct adm_device *adev;

        size_t length;
        enum dma_transfer_direction dir;
        dma_addr_t dma_addr;
        size_t dma_len;

        void *cpl;
        dma_addr_t cp_addr;
        u32 crci;
        u32 mux;
        u32 blk_size;
};

struct adm_chan {
        struct virt_dma_chan vc;
        struct adm_device *adev;

        /* parsed from DT */
        u32 id;                 /* channel id */

        struct adm_async_desc *curr_txd;
        struct dma_slave_config slave;
        struct list_head node;

        int error;
        int initialized;
};

static inline struct adm_chan *to_adm_chan(struct dma_chan *common)
{
        return container_of(common, struct adm_chan, vc.chan);
}

struct adm_device {
        void __iomem *regs;
        struct device *dev;
        struct dma_device common;
        struct device_dma_parameters dma_parms;
        struct adm_chan *channels;

        u32 ee;

        struct clk *core_clk;
        struct clk *iface_clk;

        struct reset_control *clk_reset;
        struct reset_control *c0_reset;
        struct reset_control *c1_reset;
        struct reset_control *c2_reset;
        int irq;
};

/**
 * adm_free_chan - Frees dma resources associated with the specific channel
 *
 * @chan: dma channel
 *
 * Free all allocated descriptors associated with this channel
 */
static void adm_free_chan(struct dma_chan *chan)
{
        /* free all queued descriptors */
        vchan_free_chan_resources(to_virt_chan(chan));
}

/**
 * adm_get_blksize - Get block size from burst value
 *
 * @burst: Burst size of transaction
 */
static int adm_get_blksize(unsigned int burst)
{
        int ret;

        switch (burst) {
        case 16:
        case 32:
        case 64:
        case 128:
                ret = ffs(burst >> 4) - 1;
                break;
        case 192:
                ret = 4;
                break;
        case 256:
                ret = 5;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

/**
 * adm_process_fc_descriptors - Process descriptors for flow controlled xfers
 *
 * @achan: ADM channel
 * @desc: Descriptor memory pointer
 * @sg: Scatterlist entry
 * @crci: CRCI value
 * @burst: Burst size of transaction
 * @direction: DMA transfer direction
 */
static void *adm_process_fc_descriptors(struct adm_chan *achan, void *desc,
                                        struct scatterlist *sg, u32 crci,
                                        u32 burst,
                                        enum dma_transfer_direction direction)
{
        struct adm_desc_hw_box *box_desc = NULL;
        struct adm_desc_hw_single *single_desc;
        u32 remainder = sg_dma_len(sg);
        u32 rows, row_offset, crci_cmd;
        u32 mem_addr = sg_dma_address(sg);
        u32 *incr_addr = &mem_addr;
        u32 *src, *dst;

        if (direction == DMA_DEV_TO_MEM) {
                crci_cmd = ADM_CMD_SRC_CRCI(crci);
                row_offset = burst;
                src = &achan->slave.src_addr;
                dst = &mem_addr;
        } else {
                crci_cmd = ADM_CMD_DST_CRCI(crci);
                row_offset = burst << 16;
                src = &mem_addr;
                dst = &achan->slave.dst_addr;
        }

        while (remainder >= burst) {
                box_desc = desc;
                box_desc->cmd = ADM_CMD_TYPE_BOX | crci_cmd;
                box_desc->row_offset = row_offset;
                box_desc->src_addr = *src;
                box_desc->dst_addr = *dst;

                rows = remainder / burst;
                rows = min_t(u32, rows, ADM_MAX_ROWS);
                box_desc->num_rows = rows << 16 | rows;
                box_desc->row_len = burst << 16 | burst;

                *incr_addr += burst * rows;
                remainder -= burst * rows;
                desc += sizeof(*box_desc);
        }

        /* if leftover bytes, do one single descriptor */
        if (remainder) {
                single_desc = desc;
                single_desc->cmd = ADM_CMD_TYPE_SINGLE | crci_cmd;
                single_desc->len = remainder;
                single_desc->src_addr = *src;
                single_desc->dst_addr = *dst;
                desc += sizeof(*single_desc);

                if (sg_is_last(sg))
                        single_desc->cmd |= ADM_CMD_LC;
        } else {
                if (box_desc && sg_is_last(sg))
                        box_desc->cmd |= ADM_CMD_LC;
        }

        return desc;
}

/**
 * adm_process_non_fc_descriptors - Process descriptors for non-fc xfers
 *
 * @achan: ADM channel
 * @desc: Descriptor memory pointer
 * @sg: Scatterlist entry
 * @direction: DMA transfer direction
 */
static void *adm_process_non_fc_descriptors(struct adm_chan *achan, void *desc,
                                            struct scatterlist *sg,
                                            enum dma_transfer_direction direction)
{
        struct adm_desc_hw_single *single_desc;
        u32 remainder = sg_dma_len(sg);
        u32 mem_addr = sg_dma_address(sg);
        u32 *incr_addr = &mem_addr;
        u32 *src, *dst;

        if (direction == DMA_DEV_TO_MEM) {
                src = &achan->slave.src_addr;
                dst = &mem_addr;
        } else {
                src = &mem_addr;
                dst = &achan->slave.dst_addr;
        }

        do {
                single_desc = desc;
                single_desc->cmd = ADM_CMD_TYPE_SINGLE;
                single_desc->src_addr = *src;
                single_desc->dst_addr = *dst;
                single_desc->len = (remainder > ADM_MAX_XFER) ?
                                ADM_MAX_XFER : remainder;

                remainder -= single_desc->len;
                *incr_addr += single_desc->len;
                desc += sizeof(*single_desc);
        } while (remainder);

        /* set last command if this is the end of the whole transaction */
        if (sg_is_last(sg))
                single_desc->cmd |= ADM_CMD_LC;

        return desc;
}

/**
 * adm_prep_slave_sg - Prep slave sg transaction
 *
 * @chan: dma channel
 * @sgl: scatter gather list
 * @sg_len: length of sg
 * @direction: DMA transfer direction
 * @flags: DMA flags
 * @context: transfer context (unused)
 */
static struct dma_async_tx_descriptor *adm_prep_slave_sg(struct dma_chan *chan,
                                                         struct scatterlist *sgl,
                                                         unsigned int sg_len,
                                                         enum dma_transfer_direction direction,
                                                         unsigned long flags,
                                                         void *context)
{
        struct adm_chan *achan = to_adm_chan(chan);
        struct adm_device *adev = achan->adev;
        struct adm_async_desc *async_desc;
        struct scatterlist *sg;
        dma_addr_t cple_addr;
        u32 i, burst;
        u32 single_count = 0, box_count = 0, crci = 0;
        void *desc;
        u32 *cple;
        int blk_size = 0;

        if (!is_slave_direction(direction)) {
                dev_err(adev->dev, "invalid dma direction\n");
                return NULL;
        }

        /*
         * get burst value from slave configuration
         */
        burst = (direction == DMA_MEM_TO_DEV) ?
                achan->slave.dst_maxburst :
                achan->slave.src_maxburst;

        /* if using flow control, validate burst and crci values */
        if (achan->slave.device_fc) {
                blk_size = adm_get_blksize(burst);
                if (blk_size < 0) {
                        dev_err(adev->dev, "invalid burst value: %d\n",
                                burst);
                        return ERR_PTR(-EINVAL);
                }

                crci = achan->slave.slave_id & 0xf;
                if (!crci || achan->slave.slave_id > 0x1f) {
                        dev_err(adev->dev, "invalid crci value\n");
                        return ERR_PTR(-EINVAL);
                }
        }

        /* iterate through sgs and compute allocation size of structures */
        for_each_sg(sgl, sg, sg_len, i) {
                if (achan->slave.device_fc) {
                        box_count += DIV_ROUND_UP(sg_dma_len(sg) / burst,
                                                  ADM_MAX_ROWS);
                        if (sg_dma_len(sg) % burst)
                                single_count++;
                } else {
                        single_count += DIV_ROUND_UP(sg_dma_len(sg),
                                                     ADM_MAX_XFER);
                }
        }

        async_desc = kzalloc(sizeof(*async_desc), GFP_NOWAIT);
        if (!async_desc)
                return ERR_PTR(-ENOMEM);

        if (crci)
                async_desc->mux = achan->slave.slave_id & ADM_CRCI_MUX_SEL ?
                                        ADM_CRCI_CTL_MUX_SEL : 0;
        async_desc->crci = crci;
        async_desc->blk_size = blk_size;
        async_desc->dma_len = single_count * sizeof(struct adm_desc_hw_single) +
                                box_count * sizeof(struct adm_desc_hw_box) +
                                sizeof(*cple) + 2 * ADM_DESC_ALIGN;

        async_desc->cpl = kzalloc(async_desc->dma_len, GFP_NOWAIT);
        if (!async_desc->cpl)
                goto free;

        async_desc->adev = adev;

        /* both command list entry and descriptors must be 8 byte aligned */
        cple = PTR_ALIGN(async_desc->cpl, ADM_DESC_ALIGN);
        desc = PTR_ALIGN(cple + 1, ADM_DESC_ALIGN);

        for_each_sg(sgl, sg, sg_len, i) {
                async_desc->length += sg_dma_len(sg);

                if (achan->slave.device_fc)
                        desc = adm_process_fc_descriptors(achan, desc, sg, crci,
                                                          burst, direction);
                else
                        desc = adm_process_non_fc_descriptors(achan, desc, sg,
                                                              direction);
        }

        async_desc->dma_addr = dma_map_single(adev->dev, async_desc->cpl,
                                              async_desc->dma_len,
                                              DMA_TO_DEVICE);
        if (dma_mapping_error(adev->dev, async_desc->dma_addr))
                goto free;

        cple_addr = async_desc->dma_addr + ((void *)cple - async_desc->cpl);

        /* init cmd list */
        dma_sync_single_for_cpu(adev->dev, cple_addr, sizeof(*cple),
                                DMA_TO_DEVICE);
        *cple = ADM_CPLE_LP;
        *cple |= (async_desc->dma_addr + ADM_DESC_ALIGN) >> 3;
        dma_sync_single_for_device(adev->dev, cple_addr, sizeof(*cple),
                                   DMA_TO_DEVICE);

        return vchan_tx_prep(&achan->vc, &async_desc->vd, flags);

free:
        kfree(async_desc);
        return ERR_PTR(-ENOMEM);
}

/**
 * adm_terminate_all - terminate all transactions on a channel
 * @chan: dma channel
 *
 * Dequeues and frees all transactions, aborts current transaction
 * No callbacks are done
 *
 */
static int adm_terminate_all(struct dma_chan *chan)
{
        struct adm_chan *achan = to_adm_chan(chan);
        struct adm_device *adev = achan->adev;
        unsigned long flags;
        LIST_HEAD(head);

        spin_lock_irqsave(&achan->vc.lock, flags);
        vchan_get_all_descriptors(&achan->vc, &head);

        /* send flush command to terminate current transaction */
        writel_relaxed(0x0,
                       adev->regs + ADM_CH_FLUSH_STATE0(achan->id, adev->ee));

        spin_unlock_irqrestore(&achan->vc.lock, flags);

        vchan_dma_desc_free_list(&achan->vc, &head);

        return 0;
}

static int adm_slave_config(struct dma_chan *chan, struct dma_slave_config *cfg)
{
        struct adm_chan *achan = to_adm_chan(chan);
        unsigned long flag;

        spin_lock_irqsave(&achan->vc.lock, flag);
        memcpy(&achan->slave, cfg, sizeof(struct dma_slave_config));
        spin_unlock_irqrestore(&achan->vc.lock, flag);

        return 0;
}

/**
 * adm_start_dma - start next transaction
 * @achan: ADM dma channel
 */
static void adm_start_dma(struct adm_chan *achan)
{
        struct virt_dma_desc *vd = vchan_next_desc(&achan->vc);
        struct adm_device *adev = achan->adev;
        struct adm_async_desc *async_desc;

        lockdep_assert_held(&achan->vc.lock);

        if (!vd)
                return;

        list_del(&vd->node);

        /* write next command list out to the CMD FIFO */
        async_desc = container_of(vd, struct adm_async_desc, vd);
        achan->curr_txd = async_desc;

        /* reset channel error */
        achan->error = 0;

        if (!achan->initialized) {
                /* enable interrupts */
                writel(ADM_CH_CONF_SHADOW_EN |
                       ADM_CH_CONF_PERM_MPU_CONF |
                       ADM_CH_CONF_MPU_DISABLE |
                       ADM_CH_CONF_SEC_DOMAIN(adev->ee),
                       adev->regs + ADM_CH_CONF(achan->id));

                writel(ADM_CH_RSLT_CONF_IRQ_EN | ADM_CH_RSLT_CONF_FLUSH_EN,
                       adev->regs + ADM_CH_RSLT_CONF(achan->id, adev->ee));

                achan->initialized = 1;
        }

        /* set the crci block size if this transaction requires CRCI */
        if (async_desc->crci) {
                writel(async_desc->mux | async_desc->blk_size,
                       adev->regs + ADM_CRCI_CTL(async_desc->crci, adev->ee));
        }

        /* make sure IRQ enable doesn't get reordered */
        wmb();

        /* write next command list out to the CMD FIFO */
        writel(ALIGN(async_desc->dma_addr, ADM_DESC_ALIGN) >> 3,
               adev->regs + ADM_CH_CMD_PTR(achan->id, adev->ee));
}

/**
 * adm_dma_irq - irq handler for ADM controller
 * @irq: IRQ of interrupt
 * @data: callback data
 *
 * IRQ handler for the bam controller
 */
static irqreturn_t adm_dma_irq(int irq, void *data)
{
        struct adm_device *adev = data;
        u32 srcs, i;
        struct adm_async_desc *async_desc;
        unsigned long flags;

        srcs = readl_relaxed(adev->regs +
                        ADM_SEC_DOMAIN_IRQ_STATUS(adev->ee));

        for (i = 0; i < ADM_MAX_CHANNELS; i++) {
                struct adm_chan *achan = &adev->channels[i];
                u32 status, result;

                if (srcs & BIT(i)) {
                        status = readl_relaxed(adev->regs +
                                               ADM_CH_STATUS_SD(i, adev->ee));

                        /* if no result present, skip */
                        if (!(status & ADM_CH_STATUS_VALID))
                                continue;

                        result = readl_relaxed(adev->regs +
                                ADM_CH_RSLT(i, adev->ee));

                        /* no valid results, skip */
                        if (!(result & ADM_CH_RSLT_VALID))
                                continue;

                        /* flag error if transaction was flushed or failed */
                        if (result & (ADM_CH_RSLT_ERR | ADM_CH_RSLT_FLUSH))
                                achan->error = 1;

                        spin_lock_irqsave(&achan->vc.lock, flags);
                        async_desc = achan->curr_txd;

                        achan->curr_txd = NULL;

                        if (async_desc) {
                                vchan_cookie_complete(&async_desc->vd);

                                /* kick off next DMA */
                                adm_start_dma(achan);
                        }

                        spin_unlock_irqrestore(&achan->vc.lock, flags);
                }
        }

        return IRQ_HANDLED;
}

/**
 * adm_tx_status - returns status of transaction
 * @chan: dma channel
 * @cookie: transaction cookie
 * @txstate: DMA transaction state
 *
 * Return status of dma transaction
 */
static enum dma_status adm_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
                                     struct dma_tx_state *txstate)
{
        struct adm_chan *achan = to_adm_chan(chan);
        struct virt_dma_desc *vd;
        enum dma_status ret;
        unsigned long flags;
        size_t residue = 0;

        ret = dma_cookie_status(chan, cookie, txstate);
        if (ret == DMA_COMPLETE || !txstate)
                return ret;

        spin_lock_irqsave(&achan->vc.lock, flags);

        vd = vchan_find_desc(&achan->vc, cookie);
        if (vd)
                residue = container_of(vd, struct adm_async_desc, vd)->length;

        spin_unlock_irqrestore(&achan->vc.lock, flags);

        /*
         * residue is either the full length if it is in the issued list, or 0
         * if it is in progress.  We have no reliable way of determining
         * anything inbetween
         */
        dma_set_residue(txstate, residue);

        if (achan->error)
                return DMA_ERROR;

        return ret;
}

/**
 * adm_issue_pending - starts pending transactions
 * @chan: dma channel
 *
 * Issues all pending transactions and starts DMA
 */
static void adm_issue_pending(struct dma_chan *chan)
{
        struct adm_chan *achan = to_adm_chan(chan);
        unsigned long flags;

        spin_lock_irqsave(&achan->vc.lock, flags);

        if (vchan_issue_pending(&achan->vc) && !achan->curr_txd)
                adm_start_dma(achan);
        spin_unlock_irqrestore(&achan->vc.lock, flags);
}

/**
 * adm_dma_free_desc - free descriptor memory
 * @vd: virtual descriptor
 *
 */
static void adm_dma_free_desc(struct virt_dma_desc *vd)
{
        struct adm_async_desc *async_desc = container_of(vd,
                        struct adm_async_desc, vd);

        dma_unmap_single(async_desc->adev->dev, async_desc->dma_addr,
                         async_desc->dma_len, DMA_TO_DEVICE);
        kfree(async_desc->cpl);
        kfree(async_desc);
}

static void adm_channel_init(struct adm_device *adev, struct adm_chan *achan,
                             u32 index)
{
        achan->id = index;
        achan->adev = adev;

        vchan_init(&achan->vc, &adev->common);
        achan->vc.desc_free = adm_dma_free_desc;
}

static int adm_dma_probe(struct platform_device *pdev)
{
        struct adm_device *adev;
        int ret;
        u32 i;

        adev = devm_kzalloc(&pdev->dev, sizeof(*adev), GFP_KERNEL);
        if (!adev)
                return -ENOMEM;

        adev->dev = &pdev->dev;

        adev->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(adev->regs))
                return PTR_ERR(adev->regs);

        adev->irq = platform_get_irq(pdev, 0);
        if (adev->irq < 0)
                return adev->irq;

        ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &adev->ee);
        if (ret) {
                dev_err(adev->dev, "Execution environment unspecified\n");
                return ret;
        }

        adev->core_clk = devm_clk_get(adev->dev, "core");
        if (IS_ERR(adev->core_clk))
                return PTR_ERR(adev->core_clk);

        adev->iface_clk = devm_clk_get(adev->dev, "iface");
        if (IS_ERR(adev->iface_clk))
                return PTR_ERR(adev->iface_clk);

        adev->clk_reset = devm_reset_control_get_exclusive(&pdev->dev, "clk");
        if (IS_ERR(adev->clk_reset)) {
                dev_err(adev->dev, "failed to get ADM0 reset\n");
                return PTR_ERR(adev->clk_reset);
        }

        adev->c0_reset = devm_reset_control_get_exclusive(&pdev->dev, "c0");
        if (IS_ERR(adev->c0_reset)) {
                dev_err(adev->dev, "failed to get ADM0 C0 reset\n");
                return PTR_ERR(adev->c0_reset);
        }

        adev->c1_reset = devm_reset_control_get_exclusive(&pdev->dev, "c1");
        if (IS_ERR(adev->c1_reset)) {
                dev_err(adev->dev, "failed to get ADM0 C1 reset\n");
                return PTR_ERR(adev->c1_reset);
        }

        adev->c2_reset = devm_reset_control_get_exclusive(&pdev->dev, "c2");
        if (IS_ERR(adev->c2_reset)) {
                dev_err(adev->dev, "failed to get ADM0 C2 reset\n");
                return PTR_ERR(adev->c2_reset);
        }

        ret = clk_prepare_enable(adev->core_clk);
        if (ret) {
                dev_err(adev->dev, "failed to prepare/enable core clock\n");
                return ret;
        }

        ret = clk_prepare_enable(adev->iface_clk);
        if (ret) {
                dev_err(adev->dev, "failed to prepare/enable iface clock\n");
                goto err_disable_core_clk;
        }

        reset_control_assert(adev->clk_reset);
        reset_control_assert(adev->c0_reset);
        reset_control_assert(adev->c1_reset);
        reset_control_assert(adev->c2_reset);

        udelay(2);

        reset_control_deassert(adev->clk_reset);
        reset_control_deassert(adev->c0_reset);
        reset_control_deassert(adev->c1_reset);
        reset_control_deassert(adev->c2_reset);

        adev->channels = devm_kcalloc(adev->dev, ADM_MAX_CHANNELS,
                                      sizeof(*adev->channels), GFP_KERNEL);

        if (!adev->channels) {
                ret = -ENOMEM;
                goto err_disable_clks;
        }

        /* allocate and initialize channels */
        INIT_LIST_HEAD(&adev->common.channels);

        for (i = 0; i < ADM_MAX_CHANNELS; i++)
                adm_channel_init(adev, &adev->channels[i], i);

        /* reset CRCIs */
        for (i = 0; i < 16; i++)
                writel(ADM_CRCI_CTL_RST, adev->regs +
                        ADM_CRCI_CTL(i, adev->ee));

        /* configure client interfaces */
        writel(ADM_CI_RANGE_START(0x40) | ADM_CI_RANGE_END(0xb0) |
               ADM_CI_BURST_8_WORDS, adev->regs + ADM_CI_CONF(0));
        writel(ADM_CI_RANGE_START(0x2a) | ADM_CI_RANGE_END(0x2c) |
               ADM_CI_BURST_8_WORDS, adev->regs + ADM_CI_CONF(1));
        writel(ADM_CI_RANGE_START(0x12) | ADM_CI_RANGE_END(0x28) |
               ADM_CI_BURST_8_WORDS, adev->regs + ADM_CI_CONF(2));
        writel(ADM_GP_CTL_LP_EN | ADM_GP_CTL_LP_CNT(0xf),
               adev->regs + ADM_GP_CTL);

        ret = devm_request_irq(adev->dev, adev->irq, adm_dma_irq,
                               0, "adm_dma", adev);
        if (ret)
                goto err_disable_clks;

        platform_set_drvdata(pdev, adev);

        adev->common.dev = adev->dev;
        adev->common.dev->dma_parms = &adev->dma_parms;

        /* set capabilities */
        dma_cap_zero(adev->common.cap_mask);
        dma_cap_set(DMA_SLAVE, adev->common.cap_mask);
        dma_cap_set(DMA_PRIVATE, adev->common.cap_mask);

        /* initialize dmaengine apis */
        adev->common.directions = BIT(DMA_DEV_TO_MEM | DMA_MEM_TO_DEV);
        adev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
        adev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
        adev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
        adev->common.device_free_chan_resources = adm_free_chan;
        adev->common.device_prep_slave_sg = adm_prep_slave_sg;
        adev->common.device_issue_pending = adm_issue_pending;
        adev->common.device_tx_status = adm_tx_status;
        adev->common.device_terminate_all = adm_terminate_all;
        adev->common.device_config = adm_slave_config;

        ret = dma_async_device_register(&adev->common);
        if (ret) {
                dev_err(adev->dev, "failed to register dma async device\n");
                goto err_disable_clks;
        }

        ret = of_dma_controller_register(pdev->dev.of_node,
                                         of_dma_xlate_by_chan_id,
                                         &adev->common);
        if (ret)
                goto err_unregister_dma;

        return 0;

err_unregister_dma:
        dma_async_device_unregister(&adev->common);
err_disable_clks:
        clk_disable_unprepare(adev->iface_clk);
err_disable_core_clk:
        clk_disable_unprepare(adev->core_clk);

        return ret;
}

static int adm_dma_remove(struct platform_device *pdev)
{
        struct adm_device *adev = platform_get_drvdata(pdev);
        struct adm_chan *achan;
        u32 i;

        of_dma_controller_free(pdev->dev.of_node);
        dma_async_device_unregister(&adev->common);

        for (i = 0; i < ADM_MAX_CHANNELS; i++) {
                achan = &adev->channels[i];

                /* mask IRQs for this channel/EE pair */
                writel(0, adev->regs + ADM_CH_RSLT_CONF(achan->id, adev->ee));

                tasklet_kill(&adev->channels[i].vc.task);
                adm_terminate_all(&adev->channels[i].vc.chan);
        }

        devm_free_irq(adev->dev, adev->irq, adev);

        clk_disable_unprepare(adev->core_clk);
        clk_disable_unprepare(adev->iface_clk);

        return 0;
}

static const struct of_device_id adm_of_match[] = {
        { .compatible = "qcom,adm", },
        {}
};
MODULE_DEVICE_TABLE(of, adm_of_match);

static struct platform_driver adm_dma_driver = {
        .probe = adm_dma_probe,
        .remove = adm_dma_remove,
        .driver = {
                .name = "adm-dma-engine",
                .of_match_table = adm_of_match,
        },
};

module_platform_driver(adm_dma_driver);

MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
MODULE_DESCRIPTION("QCOM ADM DMA engine driver");
MODULE_LICENSE("GPL v2");