blob: 78328677681e28ae661610dbe06a45f459fbb9ec [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* mtu3_qmu.c - Queue Management Unit driver for device controller
*
* Copyright (C) 2016 MediaTek Inc.
*
* Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
/*
* Queue Management Unit (QMU) is designed to unload SW effort
* to serve DMA interrupts.
* By preparing General Purpose Descriptor (GPD) and Buffer Descriptor (BD),
* SW links data buffers and triggers QMU to send / receive data to
* host / from device at a time.
* And now only GPD is supported.
*
* For more detailed information, please refer to QMU Programming Guide
*/
#include <linux/dmapool.h>
#include <linux/iopoll.h>
#include "mtu3.h"
#define QMU_CHECKSUM_LEN 16
#define GPD_FLAGS_HWO BIT(0)
#define GPD_FLAGS_BDP BIT(1)
#define GPD_FLAGS_BPS BIT(2)
#define GPD_FLAGS_IOC BIT(7)
#define GPD_EXT_FLAG_ZLP BIT(5)
static struct qmu_gpd *gpd_dma_to_virt(struct mtu3_gpd_ring *ring,
dma_addr_t dma_addr)
{
dma_addr_t dma_base = ring->dma;
struct qmu_gpd *gpd_head = ring->start;
u32 offset = (dma_addr - dma_base) / sizeof(*gpd_head);
if (offset >= MAX_GPD_NUM)
return NULL;
return gpd_head + offset;
}
static dma_addr_t gpd_virt_to_dma(struct mtu3_gpd_ring *ring,
struct qmu_gpd *gpd)
{
dma_addr_t dma_base = ring->dma;
struct qmu_gpd *gpd_head = ring->start;
u32 offset;
offset = gpd - gpd_head;
if (offset >= MAX_GPD_NUM)
return 0;
return dma_base + (offset * sizeof(*gpd));
}
static void gpd_ring_init(struct mtu3_gpd_ring *ring, struct qmu_gpd *gpd)
{
ring->start = gpd;
ring->enqueue = gpd;
ring->dequeue = gpd;
ring->end = gpd + MAX_GPD_NUM - 1;
}
static void reset_gpd_list(struct mtu3_ep *mep)
{
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
struct qmu_gpd *gpd = ring->start;
if (gpd) {
gpd->flag &= ~GPD_FLAGS_HWO;
gpd_ring_init(ring, gpd);
}
}
int mtu3_gpd_ring_alloc(struct mtu3_ep *mep)
{
struct qmu_gpd *gpd;
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
/* software own all gpds as default */
gpd = dma_pool_zalloc(mep->mtu->qmu_gpd_pool, GFP_ATOMIC, &ring->dma);
if (gpd == NULL)
return -ENOMEM;
gpd_ring_init(ring, gpd);
return 0;
}
void mtu3_gpd_ring_free(struct mtu3_ep *mep)
{
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
dma_pool_free(mep->mtu->qmu_gpd_pool,
ring->start, ring->dma);
memset(ring, 0, sizeof(*ring));
}
/*
* calculate check sum of a gpd or bd
* add "noinline" and "mb" to prevent wrong calculation
*/
static noinline u8 qmu_calc_checksum(u8 *data)
{
u8 chksum = 0;
int i;
data[1] = 0x0; /* set checksum to 0 */
mb(); /* ensure the gpd/bd is really up-to-date */
for (i = 0; i < QMU_CHECKSUM_LEN; i++)
chksum += data[i];
/* Default: HWO=1, @flag[bit0] */
chksum += 1;
return 0xFF - chksum;
}
void mtu3_qmu_resume(struct mtu3_ep *mep)
{
struct mtu3 *mtu = mep->mtu;
void __iomem *mbase = mtu->mac_base;
int epnum = mep->epnum;
u32 offset;
offset = mep->is_in ? USB_QMU_TQCSR(epnum) : USB_QMU_RQCSR(epnum);
mtu3_writel(mbase, offset, QMU_Q_RESUME);
if (!(mtu3_readl(mbase, offset) & QMU_Q_ACTIVE))
mtu3_writel(mbase, offset, QMU_Q_RESUME);
}
static struct qmu_gpd *advance_enq_gpd(struct mtu3_gpd_ring *ring)
{
if (ring->enqueue < ring->end)
ring->enqueue++;
else
ring->enqueue = ring->start;
return ring->enqueue;
}
static struct qmu_gpd *advance_deq_gpd(struct mtu3_gpd_ring *ring)
{
if (ring->dequeue < ring->end)
ring->dequeue++;
else
ring->dequeue = ring->start;
return ring->dequeue;
}
/* check if a ring is emtpy */
static int gpd_ring_empty(struct mtu3_gpd_ring *ring)
{
struct qmu_gpd *enq = ring->enqueue;
struct qmu_gpd *next;
if (ring->enqueue < ring->end)
next = enq + 1;
else
next = ring->start;
/* one gpd is reserved to simplify gpd preparation */
return next == ring->dequeue;
}
int mtu3_prepare_transfer(struct mtu3_ep *mep)
{
return gpd_ring_empty(&mep->gpd_ring);
}
static int mtu3_prepare_tx_gpd(struct mtu3_ep *mep, struct mtu3_request *mreq)
{
struct qmu_gpd *enq;
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
struct qmu_gpd *gpd = ring->enqueue;
struct usb_request *req = &mreq->request;
/* set all fields to zero as default value */
memset(gpd, 0, sizeof(*gpd));
gpd->buffer = cpu_to_le32((u32)req->dma);
gpd->buf_len = cpu_to_le16(req->length);
gpd->flag |= GPD_FLAGS_IOC;
/* get the next GPD */
enq = advance_enq_gpd(ring);
dev_dbg(mep->mtu->dev, "TX-EP%d queue gpd=%p, enq=%p\n",
mep->epnum, gpd, enq);
enq->flag &= ~GPD_FLAGS_HWO;
gpd->next_gpd = cpu_to_le32((u32)gpd_virt_to_dma(ring, enq));
if (req->zero)
gpd->ext_flag |= GPD_EXT_FLAG_ZLP;
gpd->chksum = qmu_calc_checksum((u8 *)gpd);
gpd->flag |= GPD_FLAGS_HWO;
mreq->gpd = gpd;
return 0;
}
static int mtu3_prepare_rx_gpd(struct mtu3_ep *mep, struct mtu3_request *mreq)
{
struct qmu_gpd *enq;
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
struct qmu_gpd *gpd = ring->enqueue;
struct usb_request *req = &mreq->request;
/* set all fields to zero as default value */
memset(gpd, 0, sizeof(*gpd));
gpd->buffer = cpu_to_le32((u32)req->dma);
gpd->data_buf_len = cpu_to_le16(req->length);
gpd->flag |= GPD_FLAGS_IOC;
/* get the next GPD */
enq = advance_enq_gpd(ring);
dev_dbg(mep->mtu->dev, "RX-EP%d queue gpd=%p, enq=%p\n",
mep->epnum, gpd, enq);
enq->flag &= ~GPD_FLAGS_HWO;
gpd->next_gpd = cpu_to_le32((u32)gpd_virt_to_dma(ring, enq));
gpd->chksum = qmu_calc_checksum((u8 *)gpd);
gpd->flag |= GPD_FLAGS_HWO;
mreq->gpd = gpd;
return 0;
}
void mtu3_insert_gpd(struct mtu3_ep *mep, struct mtu3_request *mreq)
{
if (mep->is_in)
mtu3_prepare_tx_gpd(mep, mreq);
else
mtu3_prepare_rx_gpd(mep, mreq);
}
int mtu3_qmu_start(struct mtu3_ep *mep)
{
struct mtu3 *mtu = mep->mtu;
void __iomem *mbase = mtu->mac_base;
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
u8 epnum = mep->epnum;
if (mep->is_in) {
/* set QMU start address */
mtu3_writel(mbase, USB_QMU_TQSAR(mep->epnum), ring->dma);
mtu3_setbits(mbase, MU3D_EP_TXCR0(mep->epnum), TX_DMAREQEN);
mtu3_setbits(mbase, U3D_QCR0, QMU_TX_CS_EN(epnum));
/* send zero length packet according to ZLP flag in GPD */
mtu3_setbits(mbase, U3D_QCR1, QMU_TX_ZLP(epnum));
mtu3_writel(mbase, U3D_TQERRIESR0,
QMU_TX_LEN_ERR(epnum) | QMU_TX_CS_ERR(epnum));
if (mtu3_readl(mbase, USB_QMU_TQCSR(epnum)) & QMU_Q_ACTIVE) {
dev_warn(mtu->dev, "Tx %d Active Now!\n", epnum);
return 0;
}
mtu3_writel(mbase, USB_QMU_TQCSR(epnum), QMU_Q_START);
} else {
mtu3_writel(mbase, USB_QMU_RQSAR(mep->epnum), ring->dma);
mtu3_setbits(mbase, MU3D_EP_RXCR0(mep->epnum), RX_DMAREQEN);
mtu3_setbits(mbase, U3D_QCR0, QMU_RX_CS_EN(epnum));
/* don't expect ZLP */
mtu3_clrbits(mbase, U3D_QCR3, QMU_RX_ZLP(epnum));
/* move to next GPD when receive ZLP */
mtu3_setbits(mbase, U3D_QCR3, QMU_RX_COZ(epnum));
mtu3_writel(mbase, U3D_RQERRIESR0,
QMU_RX_LEN_ERR(epnum) | QMU_RX_CS_ERR(epnum));
mtu3_writel(mbase, U3D_RQERRIESR1, QMU_RX_ZLP_ERR(epnum));
if (mtu3_readl(mbase, USB_QMU_RQCSR(epnum)) & QMU_Q_ACTIVE) {
dev_warn(mtu->dev, "Rx %d Active Now!\n", epnum);
return 0;
}
mtu3_writel(mbase, USB_QMU_RQCSR(epnum), QMU_Q_START);
}
return 0;
}
/* may called in atomic context */
void mtu3_qmu_stop(struct mtu3_ep *mep)
{
struct mtu3 *mtu = mep->mtu;
void __iomem *mbase = mtu->mac_base;
int epnum = mep->epnum;
u32 value = 0;
u32 qcsr;
int ret;
qcsr = mep->is_in ? USB_QMU_TQCSR(epnum) : USB_QMU_RQCSR(epnum);
if (!(mtu3_readl(mbase, qcsr) & QMU_Q_ACTIVE)) {
dev_dbg(mtu->dev, "%s's qmu is inactive now!\n", mep->name);
return;
}
mtu3_writel(mbase, qcsr, QMU_Q_STOP);
ret = readl_poll_timeout_atomic(mbase + qcsr, value,
!(value & QMU_Q_ACTIVE), 1, 1000);
if (ret) {
dev_err(mtu->dev, "stop %s's qmu failed\n", mep->name);
return;
}
dev_dbg(mtu->dev, "%s's qmu stop now!\n", mep->name);
}
void mtu3_qmu_flush(struct mtu3_ep *mep)
{
dev_dbg(mep->mtu->dev, "%s flush QMU %s\n", __func__,
((mep->is_in) ? "TX" : "RX"));
/*Stop QMU */
mtu3_qmu_stop(mep);
reset_gpd_list(mep);
}
/*
* QMU can't transfer zero length packet directly (a hardware limit
* on old SoCs), so when needs to send ZLP, we intentionally trigger
* a length error interrupt, and in the ISR sends a ZLP by BMU.
*/
static void qmu_tx_zlp_error_handler(struct mtu3 *mtu, u8 epnum)
{
struct mtu3_ep *mep = mtu->in_eps + epnum;
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
void __iomem *mbase = mtu->mac_base;
struct qmu_gpd *gpd_current = NULL;
dma_addr_t gpd_dma = mtu3_readl(mbase, USB_QMU_TQCPR(epnum));
struct usb_request *req = NULL;
struct mtu3_request *mreq;
u32 txcsr = 0;
int ret;
mreq = next_request(mep);
if (mreq && mreq->request.length == 0)
req = &mreq->request;
else
return;
gpd_current = gpd_dma_to_virt(ring, gpd_dma);
if (le16_to_cpu(gpd_current->buf_len) != 0) {
dev_err(mtu->dev, "TX EP%d buffer length error(!=0)\n", epnum);
return;
}
dev_dbg(mtu->dev, "%s send ZLP for req=%p\n", __func__, mreq);
mtu3_clrbits(mbase, MU3D_EP_TXCR0(mep->epnum), TX_DMAREQEN);
ret = readl_poll_timeout_atomic(mbase + MU3D_EP_TXCR0(mep->epnum),
txcsr, !(txcsr & TX_FIFOFULL), 1, 1000);
if (ret) {
dev_err(mtu->dev, "%s wait for fifo empty fail\n", __func__);
return;
}
mtu3_setbits(mbase, MU3D_EP_TXCR0(mep->epnum), TX_TXPKTRDY);
/* by pass the current GDP */
gpd_current->flag |= GPD_FLAGS_BPS;
gpd_current->chksum = qmu_calc_checksum((u8 *)gpd_current);
gpd_current->flag |= GPD_FLAGS_HWO;
/*enable DMAREQEN, switch back to QMU mode */
mtu3_setbits(mbase, MU3D_EP_TXCR0(mep->epnum), TX_DMAREQEN);
mtu3_qmu_resume(mep);
}
/*
* NOTE: request list maybe is already empty as following case:
* queue_tx --> qmu_interrupt(clear interrupt pending, schedule tasklet)-->
* queue_tx --> process_tasklet(meanwhile, the second one is transferred,
* tasklet process both of them)-->qmu_interrupt for second one.
* To avoid upper case, put qmu_done_tx in ISR directly to process it.
*/
static void qmu_done_tx(struct mtu3 *mtu, u8 epnum)
{
struct mtu3_ep *mep = mtu->in_eps + epnum;
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
void __iomem *mbase = mtu->mac_base;
struct qmu_gpd *gpd = ring->dequeue;
struct qmu_gpd *gpd_current = NULL;
dma_addr_t gpd_dma = mtu3_readl(mbase, USB_QMU_TQCPR(epnum));
struct usb_request *request = NULL;
struct mtu3_request *mreq;
/*transfer phy address got from QMU register to virtual address */
gpd_current = gpd_dma_to_virt(ring, gpd_dma);
dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n",
__func__, epnum, gpd, gpd_current, ring->enqueue);
while (gpd != gpd_current && !(gpd->flag & GPD_FLAGS_HWO)) {
mreq = next_request(mep);
if (mreq == NULL || mreq->gpd != gpd) {
dev_err(mtu->dev, "no correct TX req is found\n");
break;
}
request = &mreq->request;
request->actual = le16_to_cpu(gpd->buf_len);
mtu3_req_complete(mep, request, 0);
gpd = advance_deq_gpd(ring);
}
dev_dbg(mtu->dev, "%s EP%d, deq=%p, enq=%p, complete\n",
__func__, epnum, ring->dequeue, ring->enqueue);
}
static void qmu_done_rx(struct mtu3 *mtu, u8 epnum)
{
struct mtu3_ep *mep = mtu->out_eps + epnum;
struct mtu3_gpd_ring *ring = &mep->gpd_ring;
void __iomem *mbase = mtu->mac_base;
struct qmu_gpd *gpd = ring->dequeue;
struct qmu_gpd *gpd_current = NULL;
dma_addr_t gpd_dma = mtu3_readl(mbase, USB_QMU_RQCPR(epnum));
struct usb_request *req = NULL;
struct mtu3_request *mreq;
gpd_current = gpd_dma_to_virt(ring, gpd_dma);
dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n",
__func__, epnum, gpd, gpd_current, ring->enqueue);
while (gpd != gpd_current && !(gpd->flag & GPD_FLAGS_HWO)) {
mreq = next_request(mep);
if (mreq == NULL || mreq->gpd != gpd) {
dev_err(mtu->dev, "no correct RX req is found\n");
break;
}
req = &mreq->request;
req->actual = le16_to_cpu(gpd->buf_len);
mtu3_req_complete(mep, req, 0);
gpd = advance_deq_gpd(ring);
}
dev_dbg(mtu->dev, "%s EP%d, deq=%p, enq=%p, complete\n",
__func__, epnum, ring->dequeue, ring->enqueue);
}
static void qmu_done_isr(struct mtu3 *mtu, u32 done_status)
{
int i;
for (i = 1; i < mtu->num_eps; i++) {
if (done_status & QMU_RX_DONE_INT(i))
qmu_done_rx(mtu, i);
if (done_status & QMU_TX_DONE_INT(i))
qmu_done_tx(mtu, i);
}
}
static void qmu_exception_isr(struct mtu3 *mtu, u32 qmu_status)
{
void __iomem *mbase = mtu->mac_base;
u32 errval;
int i;
if ((qmu_status & RXQ_CSERR_INT) || (qmu_status & RXQ_LENERR_INT)) {
errval = mtu3_readl(mbase, U3D_RQERRIR0);
for (i = 1; i < mtu->num_eps; i++) {
if (errval & QMU_RX_CS_ERR(i))
dev_err(mtu->dev, "Rx %d CS error!\n", i);
if (errval & QMU_RX_LEN_ERR(i))
dev_err(mtu->dev, "RX %d Length error\n", i);
}
mtu3_writel(mbase, U3D_RQERRIR0, errval);
}
if (qmu_status & RXQ_ZLPERR_INT) {
errval = mtu3_readl(mbase, U3D_RQERRIR1);
for (i = 1; i < mtu->num_eps; i++) {
if (errval & QMU_RX_ZLP_ERR(i))
dev_dbg(mtu->dev, "RX EP%d Recv ZLP\n", i);
}
mtu3_writel(mbase, U3D_RQERRIR1, errval);
}
if ((qmu_status & TXQ_CSERR_INT) || (qmu_status & TXQ_LENERR_INT)) {
errval = mtu3_readl(mbase, U3D_TQERRIR0);
for (i = 1; i < mtu->num_eps; i++) {
if (errval & QMU_TX_CS_ERR(i))
dev_err(mtu->dev, "Tx %d checksum error!\n", i);
if (errval & QMU_TX_LEN_ERR(i))
qmu_tx_zlp_error_handler(mtu, i);
}
mtu3_writel(mbase, U3D_TQERRIR0, errval);
}
}
irqreturn_t mtu3_qmu_isr(struct mtu3 *mtu)
{
void __iomem *mbase = mtu->mac_base;
u32 qmu_status;
u32 qmu_done_status;
/* U3D_QISAR1 is read update */
qmu_status = mtu3_readl(mbase, U3D_QISAR1);
qmu_status &= mtu3_readl(mbase, U3D_QIER1);
qmu_done_status = mtu3_readl(mbase, U3D_QISAR0);
qmu_done_status &= mtu3_readl(mbase, U3D_QIER0);
mtu3_writel(mbase, U3D_QISAR0, qmu_done_status); /* W1C */
dev_dbg(mtu->dev, "=== QMUdone[tx=%x, rx=%x] QMUexp[%x] ===\n",
(qmu_done_status & 0xFFFF), qmu_done_status >> 16,
qmu_status);
if (qmu_done_status)
qmu_done_isr(mtu, qmu_done_status);
if (qmu_status)
qmu_exception_isr(mtu, qmu_status);
return IRQ_HANDLED;
}
int mtu3_qmu_init(struct mtu3 *mtu)
{
compiletime_assert(QMU_GPD_SIZE == 16, "QMU_GPD size SHOULD be 16B");
mtu->qmu_gpd_pool = dma_pool_create("QMU_GPD", mtu->dev,
QMU_GPD_RING_SIZE, QMU_GPD_SIZE, 0);
if (!mtu->qmu_gpd_pool)
return -ENOMEM;
return 0;
}
void mtu3_qmu_exit(struct mtu3 *mtu)
{
dma_pool_destroy(mtu->qmu_gpd_pool);
}