blob: 4c58da7421432cd08a2664d6f48448901ec69282 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017-2018 MediaTek Inc.
/*
* Driver for MediaTek High-Speed DMA Controller
*
* Author: Sean Wang <sean.wang@mediatek.com>
*
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/iopoll.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/refcount.h>
#include <linux/slab.h>
#include "../virt-dma.h"
#define MTK_HSDMA_USEC_POLL 20
#define MTK_HSDMA_TIMEOUT_POLL 200000
#define MTK_HSDMA_DMA_BUSWIDTHS BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
/* The default number of virtual channel */
#define MTK_HSDMA_NR_VCHANS 3
/* Only one physical channel supported */
#define MTK_HSDMA_NR_MAX_PCHANS 1
/* Macro for physical descriptor (PD) manipulation */
/* The number of PD which must be 2 of power */
#define MTK_DMA_SIZE 64
#define MTK_HSDMA_NEXT_DESP_IDX(x, y) (((x) + 1) & ((y) - 1))
#define MTK_HSDMA_LAST_DESP_IDX(x, y) (((x) - 1) & ((y) - 1))
#define MTK_HSDMA_MAX_LEN 0x3f80
#define MTK_HSDMA_ALIGN_SIZE 4
#define MTK_HSDMA_PLEN_MASK 0x3fff
#define MTK_HSDMA_DESC_PLEN(x) (((x) & MTK_HSDMA_PLEN_MASK) << 16)
#define MTK_HSDMA_DESC_PLEN_GET(x) (((x) >> 16) & MTK_HSDMA_PLEN_MASK)
/* Registers for underlying ring manipulation */
#define MTK_HSDMA_TX_BASE 0x0
#define MTK_HSDMA_TX_CNT 0x4
#define MTK_HSDMA_TX_CPU 0x8
#define MTK_HSDMA_TX_DMA 0xc
#define MTK_HSDMA_RX_BASE 0x100
#define MTK_HSDMA_RX_CNT 0x104
#define MTK_HSDMA_RX_CPU 0x108
#define MTK_HSDMA_RX_DMA 0x10c
/* Registers for global setup */
#define MTK_HSDMA_GLO 0x204
#define MTK_HSDMA_GLO_MULTI_DMA BIT(10)
#define MTK_HSDMA_TX_WB_DDONE BIT(6)
#define MTK_HSDMA_BURST_64BYTES (0x2 << 4)
#define MTK_HSDMA_GLO_RX_BUSY BIT(3)
#define MTK_HSDMA_GLO_RX_DMA BIT(2)
#define MTK_HSDMA_GLO_TX_BUSY BIT(1)
#define MTK_HSDMA_GLO_TX_DMA BIT(0)
#define MTK_HSDMA_GLO_DMA (MTK_HSDMA_GLO_TX_DMA | \
MTK_HSDMA_GLO_RX_DMA)
#define MTK_HSDMA_GLO_BUSY (MTK_HSDMA_GLO_RX_BUSY | \
MTK_HSDMA_GLO_TX_BUSY)
#define MTK_HSDMA_GLO_DEFAULT (MTK_HSDMA_GLO_TX_DMA | \
MTK_HSDMA_GLO_RX_DMA | \
MTK_HSDMA_TX_WB_DDONE | \
MTK_HSDMA_BURST_64BYTES | \
MTK_HSDMA_GLO_MULTI_DMA)
/* Registers for reset */
#define MTK_HSDMA_RESET 0x208
#define MTK_HSDMA_RST_TX BIT(0)
#define MTK_HSDMA_RST_RX BIT(16)
/* Registers for interrupt control */
#define MTK_HSDMA_DLYINT 0x20c
#define MTK_HSDMA_RXDLY_INT_EN BIT(15)
/* Interrupt fires when the pending number's more than the specified */
#define MTK_HSDMA_RXMAX_PINT(x) (((x) & 0x7f) << 8)
/* Interrupt fires when the pending time's more than the specified in 20 us */
#define MTK_HSDMA_RXMAX_PTIME(x) ((x) & 0x7f)
#define MTK_HSDMA_DLYINT_DEFAULT (MTK_HSDMA_RXDLY_INT_EN | \
MTK_HSDMA_RXMAX_PINT(20) | \
MTK_HSDMA_RXMAX_PTIME(20))
#define MTK_HSDMA_INT_STATUS 0x220
#define MTK_HSDMA_INT_ENABLE 0x228
#define MTK_HSDMA_INT_RXDONE BIT(16)
enum mtk_hsdma_vdesc_flag {
MTK_HSDMA_VDESC_FINISHED = 0x01,
};
#define IS_MTK_HSDMA_VDESC_FINISHED(x) ((x) == MTK_HSDMA_VDESC_FINISHED)
/**
* struct mtk_hsdma_pdesc - This is the struct holding info describing physical
* descriptor (PD) and its placement must be kept at
* 4-bytes alignment in little endian order.
* @desc[1-4]: The control pad used to indicate hardware how to
* deal with the descriptor such as source and
* destination address and data length. The maximum
* data length each pdesc can handle is 0x3f80 bytes
*/
struct mtk_hsdma_pdesc {
__le32 desc1;
__le32 desc2;
__le32 desc3;
__le32 desc4;
} __packed __aligned(4);
/**
* struct mtk_hsdma_vdesc - This is the struct holding info describing virtual
* descriptor (VD)
* @vd: An instance for struct virt_dma_desc
* @len: The total data size device wants to move
* @residue: The remaining data size device will move
* @dest: The destination address device wants to move to
* @src: The source address device wants to move from
*/
struct mtk_hsdma_vdesc {
struct virt_dma_desc vd;
size_t len;
size_t residue;
dma_addr_t dest;
dma_addr_t src;
};
/**
* struct mtk_hsdma_cb - This is the struct holding extra info required for RX
* ring to know what relevant VD the the PD is being
* mapped to.
* @vd: Pointer to the relevant VD.
* @flag: Flag indicating what action should be taken when VD
* is completed.
*/
struct mtk_hsdma_cb {
struct virt_dma_desc *vd;
enum mtk_hsdma_vdesc_flag flag;
};
/**
* struct mtk_hsdma_ring - This struct holds info describing underlying ring
* space
* @txd: The descriptor TX ring which describes DMA source
* information
* @rxd: The descriptor RX ring which describes DMA
* destination information
* @cb: The extra information pointed at by RX ring
* @tphys: The physical addr of TX ring
* @rphys: The physical addr of RX ring
* @cur_tptr: Pointer to the next free descriptor used by the host
* @cur_rptr: Pointer to the last done descriptor by the device
*/
struct mtk_hsdma_ring {
struct mtk_hsdma_pdesc *txd;
struct mtk_hsdma_pdesc *rxd;
struct mtk_hsdma_cb *cb;
dma_addr_t tphys;
dma_addr_t rphys;
u16 cur_tptr;
u16 cur_rptr;
};
/**
* struct mtk_hsdma_pchan - This is the struct holding info describing physical
* channel (PC)
* @ring: An instance for the underlying ring
* @sz_ring: Total size allocated for the ring
* @nr_free: Total number of free rooms in the ring. It would
* be accessed and updated frequently between IRQ
* context and user context to reflect whether ring
* can accept requests from VD.
*/
struct mtk_hsdma_pchan {
struct mtk_hsdma_ring ring;
size_t sz_ring;
atomic_t nr_free;
};
/**
* struct mtk_hsdma_vchan - This is the struct holding info describing virtual
* channel (VC)
* @vc: An instance for struct virt_dma_chan
* @issue_completion: The wait for all issued descriptors completited
* @issue_synchronize: Bool indicating channel synchronization starts
* @desc_hw_processing: List those descriptors the hardware is processing,
* which is protected by vc.lock
*/
struct mtk_hsdma_vchan {
struct virt_dma_chan vc;
struct completion issue_completion;
bool issue_synchronize;
struct list_head desc_hw_processing;
};
/**
* struct mtk_hsdma_soc - This is the struct holding differences among SoCs
* @ddone: Bit mask for DDONE
* @ls0: Bit mask for LS0
*/
struct mtk_hsdma_soc {
__le32 ddone;
__le32 ls0;
};
/**
* struct mtk_hsdma_device - This is the struct holding info describing HSDMA
* device
* @ddev: An instance for struct dma_device
* @base: The mapped register I/O base
* @clk: The clock that device internal is using
* @irq: The IRQ that device are using
* @dma_requests: The number of VCs the device supports to
* @vc: The pointer to all available VCs
* @pc: The pointer to the underlying PC
* @pc_refcnt: Track how many VCs are using the PC
* @lock: Lock protect agaisting multiple VCs access PC
* @soc: The pointer to area holding differences among
* vaious platform
*/
struct mtk_hsdma_device {
struct dma_device ddev;
void __iomem *base;
struct clk *clk;
u32 irq;
u32 dma_requests;
struct mtk_hsdma_vchan *vc;
struct mtk_hsdma_pchan *pc;
refcount_t pc_refcnt;
/* Lock used to protect against multiple VCs access PC */
spinlock_t lock;
const struct mtk_hsdma_soc *soc;
};
static struct mtk_hsdma_device *to_hsdma_dev(struct dma_chan *chan)
{
return container_of(chan->device, struct mtk_hsdma_device, ddev);
}
static inline struct mtk_hsdma_vchan *to_hsdma_vchan(struct dma_chan *chan)
{
return container_of(chan, struct mtk_hsdma_vchan, vc.chan);
}
static struct mtk_hsdma_vdesc *to_hsdma_vdesc(struct virt_dma_desc *vd)
{
return container_of(vd, struct mtk_hsdma_vdesc, vd);
}
static struct device *hsdma2dev(struct mtk_hsdma_device *hsdma)
{
return hsdma->ddev.dev;
}
static u32 mtk_dma_read(struct mtk_hsdma_device *hsdma, u32 reg)
{
return readl(hsdma->base + reg);
}
static void mtk_dma_write(struct mtk_hsdma_device *hsdma, u32 reg, u32 val)
{
writel(val, hsdma->base + reg);
}
static void mtk_dma_rmw(struct mtk_hsdma_device *hsdma, u32 reg,
u32 mask, u32 set)
{
u32 val;
val = mtk_dma_read(hsdma, reg);
val &= ~mask;
val |= set;
mtk_dma_write(hsdma, reg, val);
}
static void mtk_dma_set(struct mtk_hsdma_device *hsdma, u32 reg, u32 val)
{
mtk_dma_rmw(hsdma, reg, 0, val);
}
static void mtk_dma_clr(struct mtk_hsdma_device *hsdma, u32 reg, u32 val)
{
mtk_dma_rmw(hsdma, reg, val, 0);
}
static void mtk_hsdma_vdesc_free(struct virt_dma_desc *vd)
{
kfree(container_of(vd, struct mtk_hsdma_vdesc, vd));
}
static int mtk_hsdma_busy_wait(struct mtk_hsdma_device *hsdma)
{
u32 status = 0;
return readl_poll_timeout(hsdma->base + MTK_HSDMA_GLO, status,
!(status & MTK_HSDMA_GLO_BUSY),
MTK_HSDMA_USEC_POLL,
MTK_HSDMA_TIMEOUT_POLL);
}
static int mtk_hsdma_alloc_pchan(struct mtk_hsdma_device *hsdma,
struct mtk_hsdma_pchan *pc)
{
struct mtk_hsdma_ring *ring = &pc->ring;
int err;
memset(pc, 0, sizeof(*pc));
/*
* Allocate ring space where [0 ... MTK_DMA_SIZE - 1] is for TX ring
* and [MTK_DMA_SIZE ... 2 * MTK_DMA_SIZE - 1] is for RX ring.
*/
pc->sz_ring = 2 * MTK_DMA_SIZE * sizeof(*ring->txd);
ring->txd = dma_alloc_coherent(hsdma2dev(hsdma), pc->sz_ring,
&ring->tphys, GFP_NOWAIT);
if (!ring->txd)
return -ENOMEM;
ring->rxd = &ring->txd[MTK_DMA_SIZE];
ring->rphys = ring->tphys + MTK_DMA_SIZE * sizeof(*ring->txd);
ring->cur_tptr = 0;
ring->cur_rptr = MTK_DMA_SIZE - 1;
ring->cb = kcalloc(MTK_DMA_SIZE, sizeof(*ring->cb), GFP_NOWAIT);
if (!ring->cb) {
err = -ENOMEM;
goto err_free_dma;
}
atomic_set(&pc->nr_free, MTK_DMA_SIZE - 1);
/* Disable HSDMA and wait for the completion */
mtk_dma_clr(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DMA);
err = mtk_hsdma_busy_wait(hsdma);
if (err)
goto err_free_cb;
/* Reset */
mtk_dma_set(hsdma, MTK_HSDMA_RESET,
MTK_HSDMA_RST_TX | MTK_HSDMA_RST_RX);
mtk_dma_clr(hsdma, MTK_HSDMA_RESET,
MTK_HSDMA_RST_TX | MTK_HSDMA_RST_RX);
/* Setup HSDMA initial pointer in the ring */
mtk_dma_write(hsdma, MTK_HSDMA_TX_BASE, ring->tphys);
mtk_dma_write(hsdma, MTK_HSDMA_TX_CNT, MTK_DMA_SIZE);
mtk_dma_write(hsdma, MTK_HSDMA_TX_CPU, ring->cur_tptr);
mtk_dma_write(hsdma, MTK_HSDMA_TX_DMA, 0);
mtk_dma_write(hsdma, MTK_HSDMA_RX_BASE, ring->rphys);
mtk_dma_write(hsdma, MTK_HSDMA_RX_CNT, MTK_DMA_SIZE);
mtk_dma_write(hsdma, MTK_HSDMA_RX_CPU, ring->cur_rptr);
mtk_dma_write(hsdma, MTK_HSDMA_RX_DMA, 0);
/* Enable HSDMA */
mtk_dma_set(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DMA);
/* Setup delayed interrupt */
mtk_dma_write(hsdma, MTK_HSDMA_DLYINT, MTK_HSDMA_DLYINT_DEFAULT);
/* Enable interrupt */
mtk_dma_set(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE);
return 0;
err_free_cb:
kfree(ring->cb);
err_free_dma:
dma_free_coherent(hsdma2dev(hsdma),
pc->sz_ring, ring->txd, ring->tphys);
return err;
}
static void mtk_hsdma_free_pchan(struct mtk_hsdma_device *hsdma,
struct mtk_hsdma_pchan *pc)
{
struct mtk_hsdma_ring *ring = &pc->ring;
/* Disable HSDMA and then wait for the completion */
mtk_dma_clr(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DMA);
mtk_hsdma_busy_wait(hsdma);
/* Reset pointer in the ring */
mtk_dma_clr(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE);
mtk_dma_write(hsdma, MTK_HSDMA_TX_BASE, 0);
mtk_dma_write(hsdma, MTK_HSDMA_TX_CNT, 0);
mtk_dma_write(hsdma, MTK_HSDMA_TX_CPU, 0);
mtk_dma_write(hsdma, MTK_HSDMA_RX_BASE, 0);
mtk_dma_write(hsdma, MTK_HSDMA_RX_CNT, 0);
mtk_dma_write(hsdma, MTK_HSDMA_RX_CPU, MTK_DMA_SIZE - 1);
kfree(ring->cb);
dma_free_coherent(hsdma2dev(hsdma),
pc->sz_ring, ring->txd, ring->tphys);
}
static int mtk_hsdma_issue_pending_vdesc(struct mtk_hsdma_device *hsdma,
struct mtk_hsdma_pchan *pc,
struct mtk_hsdma_vdesc *hvd)
{
struct mtk_hsdma_ring *ring = &pc->ring;
struct mtk_hsdma_pdesc *txd, *rxd;
u16 reserved, prev, tlen, num_sgs;
unsigned long flags;
/* Protect against PC is accessed by multiple VCs simultaneously */
spin_lock_irqsave(&hsdma->lock, flags);
/*
* Reserve rooms, where pc->nr_free is used to track how many free
* rooms in the ring being updated in user and IRQ context.
*/
num_sgs = DIV_ROUND_UP(hvd->len, MTK_HSDMA_MAX_LEN);
reserved = min_t(u16, num_sgs, atomic_read(&pc->nr_free));
if (!reserved) {
spin_unlock_irqrestore(&hsdma->lock, flags);
return -ENOSPC;
}
atomic_sub(reserved, &pc->nr_free);
while (reserved--) {
/* Limit size by PD capability for valid data moving */
tlen = (hvd->len > MTK_HSDMA_MAX_LEN) ?
MTK_HSDMA_MAX_LEN : hvd->len;
/*
* Setup PDs using the remaining VD info mapped on those
* reserved rooms. And since RXD is shared memory between the
* host and the device allocated by dma_alloc_coherent call,
* the helper macro WRITE_ONCE can ensure the data written to
* RAM would really happens.
*/
txd = &ring->txd[ring->cur_tptr];
WRITE_ONCE(txd->desc1, hvd->src);
WRITE_ONCE(txd->desc2,
hsdma->soc->ls0 | MTK_HSDMA_DESC_PLEN(tlen));
rxd = &ring->rxd[ring->cur_tptr];
WRITE_ONCE(rxd->desc1, hvd->dest);
WRITE_ONCE(rxd->desc2, MTK_HSDMA_DESC_PLEN(tlen));
/* Associate VD, the PD belonged to */
ring->cb[ring->cur_tptr].vd = &hvd->vd;
/* Move forward the pointer of TX ring */
ring->cur_tptr = MTK_HSDMA_NEXT_DESP_IDX(ring->cur_tptr,
MTK_DMA_SIZE);
/* Update VD with remaining data */
hvd->src += tlen;
hvd->dest += tlen;
hvd->len -= tlen;
}
/*
* Tagging flag for the last PD for VD will be responsible for
* completing VD.
*/
if (!hvd->len) {
prev = MTK_HSDMA_LAST_DESP_IDX(ring->cur_tptr, MTK_DMA_SIZE);
ring->cb[prev].flag = MTK_HSDMA_VDESC_FINISHED;
}
/* Ensure all changes indeed done before we're going on */
wmb();
/*
* Updating into hardware the pointer of TX ring lets HSDMA to take
* action for those pending PDs.
*/
mtk_dma_write(hsdma, MTK_HSDMA_TX_CPU, ring->cur_tptr);
spin_unlock_irqrestore(&hsdma->lock, flags);
return 0;
}
static void mtk_hsdma_issue_vchan_pending(struct mtk_hsdma_device *hsdma,
struct mtk_hsdma_vchan *hvc)
{
struct virt_dma_desc *vd, *vd2;
int err;
lockdep_assert_held(&hvc->vc.lock);
list_for_each_entry_safe(vd, vd2, &hvc->vc.desc_issued, node) {
struct mtk_hsdma_vdesc *hvd;
hvd = to_hsdma_vdesc(vd);
/* Map VD into PC and all VCs shares a single PC */
err = mtk_hsdma_issue_pending_vdesc(hsdma, hsdma->pc, hvd);
/*
* Move VD from desc_issued to desc_hw_processing when entire
* VD is fit into available PDs. Otherwise, the uncompleted
* VDs would stay in list desc_issued and then restart the
* processing as soon as possible once underlying ring space
* got freed.
*/
if (err == -ENOSPC || hvd->len > 0)
break;
/*
* The extra list desc_hw_processing is used because
* hardware can't provide sufficient information allowing us
* to know what VDs are still working on the underlying ring.
* Through the additional list, it can help us to implement
* terminate_all, residue calculation and such thing needed
* to know detail descriptor status on the hardware.
*/
list_move_tail(&vd->node, &hvc->desc_hw_processing);
}
}
static void mtk_hsdma_free_rooms_in_ring(struct mtk_hsdma_device *hsdma)
{
struct mtk_hsdma_vchan *hvc;
struct mtk_hsdma_pdesc *rxd;
struct mtk_hsdma_vdesc *hvd;
struct mtk_hsdma_pchan *pc;
struct mtk_hsdma_cb *cb;
int i = MTK_DMA_SIZE;
__le32 desc2;
u32 status;
u16 next;
/* Read IRQ status */
status = mtk_dma_read(hsdma, MTK_HSDMA_INT_STATUS);
if (unlikely(!(status & MTK_HSDMA_INT_RXDONE)))
goto rx_done;
pc = hsdma->pc;
/*
* Using a fail-safe loop with iterations of up to MTK_DMA_SIZE to
* reclaim these finished descriptors: The most number of PDs the ISR
* can handle at one time shouldn't be more than MTK_DMA_SIZE so we
* take it as limited count instead of just using a dangerous infinite
* poll.
*/
while (i--) {
next = MTK_HSDMA_NEXT_DESP_IDX(pc->ring.cur_rptr,
MTK_DMA_SIZE);
rxd = &pc->ring.rxd[next];
/*
* If MTK_HSDMA_DESC_DDONE is no specified, that means data
* moving for the PD is still under going.
*/
desc2 = READ_ONCE(rxd->desc2);
if (!(desc2 & hsdma->soc->ddone))
break;
cb = &pc->ring.cb[next];
if (unlikely(!cb->vd)) {
dev_err(hsdma2dev(hsdma), "cb->vd cannot be null\n");
break;
}
/* Update residue of VD the associated PD belonged to */
hvd = to_hsdma_vdesc(cb->vd);
hvd->residue -= MTK_HSDMA_DESC_PLEN_GET(rxd->desc2);
/* Complete VD until the relevant last PD is finished */
if (IS_MTK_HSDMA_VDESC_FINISHED(cb->flag)) {
hvc = to_hsdma_vchan(cb->vd->tx.chan);
spin_lock(&hvc->vc.lock);
/* Remove VD from list desc_hw_processing */
list_del(&cb->vd->node);
/* Add VD into list desc_completed */
vchan_cookie_complete(cb->vd);
if (hvc->issue_synchronize &&
list_empty(&hvc->desc_hw_processing)) {
complete(&hvc->issue_completion);
hvc->issue_synchronize = false;
}
spin_unlock(&hvc->vc.lock);
cb->flag = 0;
}
cb->vd = 0;
/*
* Recycle the RXD with the helper WRITE_ONCE that can ensure
* data written into RAM would really happens.
*/
WRITE_ONCE(rxd->desc1, 0);
WRITE_ONCE(rxd->desc2, 0);
pc->ring.cur_rptr = next;
/* Release rooms */
atomic_inc(&pc->nr_free);
}
/* Ensure all changes indeed done before we're going on */
wmb();
/* Update CPU pointer for those completed PDs */
mtk_dma_write(hsdma, MTK_HSDMA_RX_CPU, pc->ring.cur_rptr);
/*
* Acking the pending IRQ allows hardware no longer to keep the used
* IRQ line in certain trigger state when software has completed all
* the finished physical descriptors.
*/
if (atomic_read(&pc->nr_free) >= MTK_DMA_SIZE - 1)
mtk_dma_write(hsdma, MTK_HSDMA_INT_STATUS, status);
/* ASAP handles pending VDs in all VCs after freeing some rooms */
for (i = 0; i < hsdma->dma_requests; i++) {
hvc = &hsdma->vc[i];
spin_lock(&hvc->vc.lock);
mtk_hsdma_issue_vchan_pending(hsdma, hvc);
spin_unlock(&hvc->vc.lock);
}
rx_done:
/* All completed PDs are cleaned up, so enable interrupt again */
mtk_dma_set(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE);
}
static irqreturn_t mtk_hsdma_irq(int irq, void *devid)
{
struct mtk_hsdma_device *hsdma = devid;
/*
* Disable interrupt until all completed PDs are cleaned up in
* mtk_hsdma_free_rooms call.
*/
mtk_dma_clr(hsdma, MTK_HSDMA_INT_ENABLE, MTK_HSDMA_INT_RXDONE);
mtk_hsdma_free_rooms_in_ring(hsdma);
return IRQ_HANDLED;
}
static struct virt_dma_desc *mtk_hsdma_find_active_desc(struct dma_chan *c,
dma_cookie_t cookie)
{
struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c);
struct virt_dma_desc *vd;
list_for_each_entry(vd, &hvc->desc_hw_processing, node)
if (vd->tx.cookie == cookie)
return vd;
list_for_each_entry(vd, &hvc->vc.desc_issued, node)
if (vd->tx.cookie == cookie)
return vd;
return NULL;
}
static enum dma_status mtk_hsdma_tx_status(struct dma_chan *c,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c);
struct mtk_hsdma_vdesc *hvd;
struct virt_dma_desc *vd;
enum dma_status ret;
unsigned long flags;
size_t bytes = 0;
ret = dma_cookie_status(c, cookie, txstate);
if (ret == DMA_COMPLETE || !txstate)
return ret;
spin_lock_irqsave(&hvc->vc.lock, flags);
vd = mtk_hsdma_find_active_desc(c, cookie);
spin_unlock_irqrestore(&hvc->vc.lock, flags);
if (vd) {
hvd = to_hsdma_vdesc(vd);
bytes = hvd->residue;
}
dma_set_residue(txstate, bytes);
return ret;
}
static void mtk_hsdma_issue_pending(struct dma_chan *c)
{
struct mtk_hsdma_device *hsdma = to_hsdma_dev(c);
struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c);
unsigned long flags;
spin_lock_irqsave(&hvc->vc.lock, flags);
if (vchan_issue_pending(&hvc->vc))
mtk_hsdma_issue_vchan_pending(hsdma, hvc);
spin_unlock_irqrestore(&hvc->vc.lock, flags);
}
static struct dma_async_tx_descriptor *
mtk_hsdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest,
dma_addr_t src, size_t len, unsigned long flags)
{
struct mtk_hsdma_vdesc *hvd;
hvd = kzalloc(sizeof(*hvd), GFP_NOWAIT);
if (!hvd)
return NULL;
hvd->len = len;
hvd->residue = len;
hvd->src = src;
hvd->dest = dest;
return vchan_tx_prep(to_virt_chan(c), &hvd->vd, flags);
}
static int mtk_hsdma_free_inactive_desc(struct dma_chan *c)
{
struct virt_dma_chan *vc = to_virt_chan(c);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&vc->lock, flags);
list_splice_tail_init(&vc->desc_allocated, &head);
list_splice_tail_init(&vc->desc_submitted, &head);
list_splice_tail_init(&vc->desc_issued, &head);
spin_unlock_irqrestore(&vc->lock, flags);
/* At the point, we don't expect users put descriptor into VC again */
vchan_dma_desc_free_list(vc, &head);
return 0;
}
static void mtk_hsdma_free_active_desc(struct dma_chan *c)
{
struct mtk_hsdma_vchan *hvc = to_hsdma_vchan(c);
bool sync_needed = false;
/*
* Once issue_synchronize is being set, which means once the hardware
* consumes all descriptors for the channel in the ring, the
* synchronization must be be notified immediately it is completed.
*/
spin_lock(&hvc->vc.lock);
if (!list_empty(&hvc->desc_hw_processing)) {
hvc->issue_synchronize = true;
sync_needed = true;
}
spin_unlock(&hvc->vc.lock);
if (sync_needed)
wait_for_completion(&hvc->issue_completion);
/*
* At the point, we expect that all remaining descriptors in the ring
* for the channel should be all processing done.
*/
WARN_ONCE(!list_empty(&hvc->desc_hw_processing),
"Desc pending still in list desc_hw_processing\n");
/* Free all descriptors in list desc_completed */
vchan_synchronize(&hvc->vc);
WARN_ONCE(!list_empty(&hvc->vc.desc_completed),
"Desc pending still in list desc_completed\n");
}
static int mtk_hsdma_terminate_all(struct dma_chan *c)
{
/*
* Free pending descriptors not processed yet by hardware that have
* previously been submitted to the channel.
*/
mtk_hsdma_free_inactive_desc(c);
/*
* However, the DMA engine doesn't provide any way to stop these
* descriptors being processed currently by hardware. The only way is
* to just waiting until these descriptors are all processed completely
* through mtk_hsdma_free_active_desc call.
*/
mtk_hsdma_free_active_desc(c);
return 0;
}
static int mtk_hsdma_alloc_chan_resources(struct dma_chan *c)
{
struct mtk_hsdma_device *hsdma = to_hsdma_dev(c);
int err;
/*
* Since HSDMA has only one PC, the resource for PC is being allocated
* when the first VC is being created and the other VCs would run on
* the same PC.
*/
if (!refcount_read(&hsdma->pc_refcnt)) {
err = mtk_hsdma_alloc_pchan(hsdma, hsdma->pc);
if (err)
return err;
/*
* refcount_inc would complain increment on 0; use-after-free.
* Thus, we need to explicitly set it as 1 initially.
*/
refcount_set(&hsdma->pc_refcnt, 1);
} else {
refcount_inc(&hsdma->pc_refcnt);
}
return 0;
}
static void mtk_hsdma_free_chan_resources(struct dma_chan *c)
{
struct mtk_hsdma_device *hsdma = to_hsdma_dev(c);
/* Free all descriptors in all lists on the VC */
mtk_hsdma_terminate_all(c);
/* The resource for PC is not freed until all the VCs are destroyed */
if (!refcount_dec_and_test(&hsdma->pc_refcnt))
return;
mtk_hsdma_free_pchan(hsdma, hsdma->pc);
}
static int mtk_hsdma_hw_init(struct mtk_hsdma_device *hsdma)
{
int err;
pm_runtime_enable(hsdma2dev(hsdma));
pm_runtime_get_sync(hsdma2dev(hsdma));
err = clk_prepare_enable(hsdma->clk);
if (err)
return err;
mtk_dma_write(hsdma, MTK_HSDMA_INT_ENABLE, 0);
mtk_dma_write(hsdma, MTK_HSDMA_GLO, MTK_HSDMA_GLO_DEFAULT);
return 0;
}
static int mtk_hsdma_hw_deinit(struct mtk_hsdma_device *hsdma)
{
mtk_dma_write(hsdma, MTK_HSDMA_GLO, 0);
clk_disable_unprepare(hsdma->clk);
pm_runtime_put_sync(hsdma2dev(hsdma));
pm_runtime_disable(hsdma2dev(hsdma));
return 0;
}
static const struct mtk_hsdma_soc mt7623_soc = {
.ddone = BIT(31),
.ls0 = BIT(30),
};
static const struct mtk_hsdma_soc mt7622_soc = {
.ddone = BIT(15),
.ls0 = BIT(14),
};
static const struct of_device_id mtk_hsdma_match[] = {
{ .compatible = "mediatek,mt7623-hsdma", .data = &mt7623_soc},
{ .compatible = "mediatek,mt7622-hsdma", .data = &mt7622_soc},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mtk_hsdma_match);
static int mtk_hsdma_probe(struct platform_device *pdev)
{
struct mtk_hsdma_device *hsdma;
struct mtk_hsdma_vchan *vc;
struct dma_device *dd;
struct resource *res;
int i, err;
hsdma = devm_kzalloc(&pdev->dev, sizeof(*hsdma), GFP_KERNEL);
if (!hsdma)
return -ENOMEM;
dd = &hsdma->ddev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hsdma->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hsdma->base))
return PTR_ERR(hsdma->base);
hsdma->soc = of_device_get_match_data(&pdev->dev);
if (!hsdma->soc) {
dev_err(&pdev->dev, "No device match found\n");
return -ENODEV;
}
hsdma->clk = devm_clk_get(&pdev->dev, "hsdma");
if (IS_ERR(hsdma->clk)) {
dev_err(&pdev->dev, "No clock for %s\n",
dev_name(&pdev->dev));
return PTR_ERR(hsdma->clk);
}
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_err(&pdev->dev, "No irq resource for %s\n",
dev_name(&pdev->dev));
return -EINVAL;
}
hsdma->irq = res->start;
refcount_set(&hsdma->pc_refcnt, 0);
spin_lock_init(&hsdma->lock);
dma_cap_set(DMA_MEMCPY, dd->cap_mask);
dd->copy_align = MTK_HSDMA_ALIGN_SIZE;
dd->device_alloc_chan_resources = mtk_hsdma_alloc_chan_resources;
dd->device_free_chan_resources = mtk_hsdma_free_chan_resources;
dd->device_tx_status = mtk_hsdma_tx_status;
dd->device_issue_pending = mtk_hsdma_issue_pending;
dd->device_prep_dma_memcpy = mtk_hsdma_prep_dma_memcpy;
dd->device_terminate_all = mtk_hsdma_terminate_all;
dd->src_addr_widths = MTK_HSDMA_DMA_BUSWIDTHS;
dd->dst_addr_widths = MTK_HSDMA_DMA_BUSWIDTHS;
dd->directions = BIT(DMA_MEM_TO_MEM);
dd->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
dd->dev = &pdev->dev;
INIT_LIST_HEAD(&dd->channels);
hsdma->dma_requests = MTK_HSDMA_NR_VCHANS;
if (pdev->dev.of_node && of_property_read_u32(pdev->dev.of_node,
"dma-requests",
&hsdma->dma_requests)) {
dev_info(&pdev->dev,
"Using %u as missing dma-requests property\n",
MTK_HSDMA_NR_VCHANS);
}
hsdma->pc = devm_kcalloc(&pdev->dev, MTK_HSDMA_NR_MAX_PCHANS,
sizeof(*hsdma->pc), GFP_KERNEL);
if (!hsdma->pc)
return -ENOMEM;
hsdma->vc = devm_kcalloc(&pdev->dev, hsdma->dma_requests,
sizeof(*hsdma->vc), GFP_KERNEL);
if (!hsdma->vc)
return -ENOMEM;
for (i = 0; i < hsdma->dma_requests; i++) {
vc = &hsdma->vc[i];
vc->vc.desc_free = mtk_hsdma_vdesc_free;
vchan_init(&vc->vc, dd);
init_completion(&vc->issue_completion);
INIT_LIST_HEAD(&vc->desc_hw_processing);
}
err = dma_async_device_register(dd);
if (err)
return err;
err = of_dma_controller_register(pdev->dev.of_node,
of_dma_xlate_by_chan_id, hsdma);
if (err) {
dev_err(&pdev->dev,
"MediaTek HSDMA OF registration failed %d\n", err);
goto err_unregister;
}
mtk_hsdma_hw_init(hsdma);
err = devm_request_irq(&pdev->dev, hsdma->irq,
mtk_hsdma_irq, 0,
dev_name(&pdev->dev), hsdma);
if (err) {
dev_err(&pdev->dev,
"request_irq failed with err %d\n", err);
goto err_free;
}
platform_set_drvdata(pdev, hsdma);
dev_info(&pdev->dev, "MediaTek HSDMA driver registered\n");
return 0;
err_free:
of_dma_controller_free(pdev->dev.of_node);
err_unregister:
dma_async_device_unregister(dd);
return err;
}
static int mtk_hsdma_remove(struct platform_device *pdev)
{
struct mtk_hsdma_device *hsdma = platform_get_drvdata(pdev);
struct mtk_hsdma_vchan *vc;
int i;
/* Kill VC task */
for (i = 0; i < hsdma->dma_requests; i++) {
vc = &hsdma->vc[i];
list_del(&vc->vc.chan.device_node);
tasklet_kill(&vc->vc.task);
}
/* Disable DMA interrupt */
mtk_dma_write(hsdma, MTK_HSDMA_INT_ENABLE, 0);
/* Waits for any pending IRQ handlers to complete */
synchronize_irq(hsdma->irq);
/* Disable hardware */
mtk_hsdma_hw_deinit(hsdma);
dma_async_device_unregister(&hsdma->ddev);
of_dma_controller_free(pdev->dev.of_node);
return 0;
}
static struct platform_driver mtk_hsdma_driver = {
.probe = mtk_hsdma_probe,
.remove = mtk_hsdma_remove,
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = mtk_hsdma_match,
},
};
module_platform_driver(mtk_hsdma_driver);
MODULE_DESCRIPTION("MediaTek High-Speed DMA Controller Driver");
MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_LICENSE("GPL v2");