linux/drivers/net/davinci_cpdma.c
Cyril Chemparathy ef8c2dab01 net: davinci_emac: separate out cpdma code
In addition to being embedded into the EMAC controller, the CPDMA hardware
block is used in TI's CPSW switch controller.  Fortunately, the programming
interface to this hardware block remains pretty nicely consistent across these
devices.

This patch adds a new CPDMA services layer, which can then be reused across
EMAC and CPSW drivers.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Tested-by: Michael Williamson <michael.williamson@criticallink.com>
Tested-by: Caglar Akyuz <caglarakyuz@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2010-09-24 07:40:31 -07:00

966 lines
25 KiB
C

/*
* Texas Instruments CPDMA Driver
*
* Copyright (C) 2010 Texas Instruments
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include "davinci_cpdma.h"
/* DMA Registers */
#define CPDMA_TXIDVER 0x00
#define CPDMA_TXCONTROL 0x04
#define CPDMA_TXTEARDOWN 0x08
#define CPDMA_RXIDVER 0x10
#define CPDMA_RXCONTROL 0x14
#define CPDMA_SOFTRESET 0x1c
#define CPDMA_RXTEARDOWN 0x18
#define CPDMA_TXINTSTATRAW 0x80
#define CPDMA_TXINTSTATMASKED 0x84
#define CPDMA_TXINTMASKSET 0x88
#define CPDMA_TXINTMASKCLEAR 0x8c
#define CPDMA_MACINVECTOR 0x90
#define CPDMA_MACEOIVECTOR 0x94
#define CPDMA_RXINTSTATRAW 0xa0
#define CPDMA_RXINTSTATMASKED 0xa4
#define CPDMA_RXINTMASKSET 0xa8
#define CPDMA_RXINTMASKCLEAR 0xac
#define CPDMA_DMAINTSTATRAW 0xb0
#define CPDMA_DMAINTSTATMASKED 0xb4
#define CPDMA_DMAINTMASKSET 0xb8
#define CPDMA_DMAINTMASKCLEAR 0xbc
#define CPDMA_DMAINT_HOSTERR BIT(1)
/* the following exist only if has_ext_regs is set */
#define CPDMA_DMACONTROL 0x20
#define CPDMA_DMASTATUS 0x24
#define CPDMA_RXBUFFOFS 0x28
#define CPDMA_EM_CONTROL 0x2c
/* Descriptor mode bits */
#define CPDMA_DESC_SOP BIT(31)
#define CPDMA_DESC_EOP BIT(30)
#define CPDMA_DESC_OWNER BIT(29)
#define CPDMA_DESC_EOQ BIT(28)
#define CPDMA_DESC_TD_COMPLETE BIT(27)
#define CPDMA_DESC_PASS_CRC BIT(26)
#define CPDMA_TEARDOWN_VALUE 0xfffffffc
struct cpdma_desc {
/* hardware fields */
u32 hw_next;
u32 hw_buffer;
u32 hw_len;
u32 hw_mode;
/* software fields */
void *sw_token;
u32 sw_buffer;
u32 sw_len;
};
struct cpdma_desc_pool {
u32 phys;
void __iomem *iomap; /* ioremap map */
void *cpumap; /* dma_alloc map */
int desc_size, mem_size;
int num_desc, used_desc;
unsigned long *bitmap;
struct device *dev;
spinlock_t lock;
};
enum cpdma_state {
CPDMA_STATE_IDLE,
CPDMA_STATE_ACTIVE,
CPDMA_STATE_TEARDOWN,
};
const char *cpdma_state_str[] = { "idle", "active", "teardown" };
struct cpdma_ctlr {
enum cpdma_state state;
struct cpdma_params params;
struct device *dev;
struct cpdma_desc_pool *pool;
spinlock_t lock;
struct cpdma_chan *channels[2 * CPDMA_MAX_CHANNELS];
};
struct cpdma_chan {
enum cpdma_state state;
struct cpdma_ctlr *ctlr;
int chan_num;
spinlock_t lock;
struct cpdma_desc __iomem *head, *tail;
int count;
void __iomem *hdp, *cp, *rxfree;
u32 mask;
cpdma_handler_fn handler;
enum dma_data_direction dir;
struct cpdma_chan_stats stats;
/* offsets into dmaregs */
int int_set, int_clear, td;
};
/* The following make access to common cpdma_ctlr params more readable */
#define dmaregs params.dmaregs
#define num_chan params.num_chan
/* various accessors */
#define dma_reg_read(ctlr, ofs) __raw_readl((ctlr)->dmaregs + (ofs))
#define chan_read(chan, fld) __raw_readl((chan)->fld)
#define desc_read(desc, fld) __raw_readl(&(desc)->fld)
#define dma_reg_write(ctlr, ofs, v) __raw_writel(v, (ctlr)->dmaregs + (ofs))
#define chan_write(chan, fld, v) __raw_writel(v, (chan)->fld)
#define desc_write(desc, fld, v) __raw_writel((u32)(v), &(desc)->fld)
/*
* Utility constructs for a cpdma descriptor pool. Some devices (e.g. davinci
* emac) have dedicated on-chip memory for these descriptors. Some other
* devices (e.g. cpsw switches) use plain old memory. Descriptor pools
* abstract out these details
*/
static struct cpdma_desc_pool *
cpdma_desc_pool_create(struct device *dev, u32 phys, int size, int align)
{
int bitmap_size;
struct cpdma_desc_pool *pool;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool)
return NULL;
spin_lock_init(&pool->lock);
pool->dev = dev;
pool->mem_size = size;
pool->desc_size = ALIGN(sizeof(struct cpdma_desc), align);
pool->num_desc = size / pool->desc_size;
bitmap_size = (pool->num_desc / BITS_PER_LONG) * sizeof(long);
pool->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
if (!pool->bitmap)
goto fail;
if (phys) {
pool->phys = phys;
pool->iomap = ioremap(phys, size);
} else {
pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
GFP_KERNEL);
pool->iomap = (void __force __iomem *)pool->cpumap;
}
if (pool->iomap)
return pool;
fail:
kfree(pool->bitmap);
kfree(pool);
return NULL;
}
static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool)
{
unsigned long flags;
if (!pool)
return;
spin_lock_irqsave(&pool->lock, flags);
WARN_ON(pool->used_desc);
kfree(pool->bitmap);
if (pool->cpumap) {
dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap,
pool->phys);
} else {
iounmap(pool->iomap);
}
spin_unlock_irqrestore(&pool->lock, flags);
kfree(pool);
}
static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
struct cpdma_desc __iomem *desc)
{
if (!desc)
return 0;
return pool->phys + (__force dma_addr_t)desc -
(__force dma_addr_t)pool->iomap;
}
static inline struct cpdma_desc __iomem *
desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
{
return dma ? pool->iomap + dma - pool->phys : NULL;
}
static struct cpdma_desc __iomem *
cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc)
{
unsigned long flags;
int index;
struct cpdma_desc __iomem *desc = NULL;
spin_lock_irqsave(&pool->lock, flags);
index = bitmap_find_next_zero_area(pool->bitmap, pool->num_desc, 0,
num_desc, 0);
if (index < pool->num_desc) {
bitmap_set(pool->bitmap, index, num_desc);
desc = pool->iomap + pool->desc_size * index;
pool->used_desc++;
}
spin_unlock_irqrestore(&pool->lock, flags);
return desc;
}
static void cpdma_desc_free(struct cpdma_desc_pool *pool,
struct cpdma_desc __iomem *desc, int num_desc)
{
unsigned long flags, index;
index = ((unsigned long)desc - (unsigned long)pool->iomap) /
pool->desc_size;
spin_lock_irqsave(&pool->lock, flags);
bitmap_clear(pool->bitmap, index, num_desc);
pool->used_desc--;
spin_unlock_irqrestore(&pool->lock, flags);
}
struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
{
struct cpdma_ctlr *ctlr;
ctlr = kzalloc(sizeof(*ctlr), GFP_KERNEL);
if (!ctlr)
return NULL;
ctlr->state = CPDMA_STATE_IDLE;
ctlr->params = *params;
ctlr->dev = params->dev;
spin_lock_init(&ctlr->lock);
ctlr->pool = cpdma_desc_pool_create(ctlr->dev,
ctlr->params.desc_mem_phys,
ctlr->params.desc_mem_size,
ctlr->params.desc_align);
if (!ctlr->pool) {
kfree(ctlr);
return NULL;
}
if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
ctlr->num_chan = CPDMA_MAX_CHANNELS;
return ctlr;
}
int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
{
unsigned long flags;
int i;
spin_lock_irqsave(&ctlr->lock, flags);
if (ctlr->state != CPDMA_STATE_IDLE) {
spin_unlock_irqrestore(&ctlr->lock, flags);
return -EBUSY;
}
if (ctlr->params.has_soft_reset) {
unsigned long timeout = jiffies + HZ/10;
dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
while (time_before(jiffies, timeout)) {
if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
break;
}
WARN_ON(!time_before(jiffies, timeout));
}
for (i = 0; i < ctlr->num_chan; i++) {
__raw_writel(0, ctlr->params.txhdp + 4 * i);
__raw_writel(0, ctlr->params.rxhdp + 4 * i);
__raw_writel(0, ctlr->params.txcp + 4 * i);
__raw_writel(0, ctlr->params.rxcp + 4 * i);
}
dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
ctlr->state = CPDMA_STATE_ACTIVE;
for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
if (ctlr->channels[i])
cpdma_chan_start(ctlr->channels[i]);
}
spin_unlock_irqrestore(&ctlr->lock, flags);
return 0;
}
int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
{
unsigned long flags;
int i;
spin_lock_irqsave(&ctlr->lock, flags);
if (ctlr->state != CPDMA_STATE_ACTIVE) {
spin_unlock_irqrestore(&ctlr->lock, flags);
return -EINVAL;
}
ctlr->state = CPDMA_STATE_TEARDOWN;
for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
if (ctlr->channels[i])
cpdma_chan_stop(ctlr->channels[i]);
}
dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
ctlr->state = CPDMA_STATE_IDLE;
spin_unlock_irqrestore(&ctlr->lock, flags);
return 0;
}
int cpdma_ctlr_dump(struct cpdma_ctlr *ctlr)
{
struct device *dev = ctlr->dev;
unsigned long flags;
int i;
spin_lock_irqsave(&ctlr->lock, flags);
dev_info(dev, "CPDMA: state: %s", cpdma_state_str[ctlr->state]);
dev_info(dev, "CPDMA: txidver: %x",
dma_reg_read(ctlr, CPDMA_TXIDVER));
dev_info(dev, "CPDMA: txcontrol: %x",
dma_reg_read(ctlr, CPDMA_TXCONTROL));
dev_info(dev, "CPDMA: txteardown: %x",
dma_reg_read(ctlr, CPDMA_TXTEARDOWN));
dev_info(dev, "CPDMA: rxidver: %x",
dma_reg_read(ctlr, CPDMA_RXIDVER));
dev_info(dev, "CPDMA: rxcontrol: %x",
dma_reg_read(ctlr, CPDMA_RXCONTROL));
dev_info(dev, "CPDMA: softreset: %x",
dma_reg_read(ctlr, CPDMA_SOFTRESET));
dev_info(dev, "CPDMA: rxteardown: %x",
dma_reg_read(ctlr, CPDMA_RXTEARDOWN));
dev_info(dev, "CPDMA: txintstatraw: %x",
dma_reg_read(ctlr, CPDMA_TXINTSTATRAW));
dev_info(dev, "CPDMA: txintstatmasked: %x",
dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED));
dev_info(dev, "CPDMA: txintmaskset: %x",
dma_reg_read(ctlr, CPDMA_TXINTMASKSET));
dev_info(dev, "CPDMA: txintmaskclear: %x",
dma_reg_read(ctlr, CPDMA_TXINTMASKCLEAR));
dev_info(dev, "CPDMA: macinvector: %x",
dma_reg_read(ctlr, CPDMA_MACINVECTOR));
dev_info(dev, "CPDMA: maceoivector: %x",
dma_reg_read(ctlr, CPDMA_MACEOIVECTOR));
dev_info(dev, "CPDMA: rxintstatraw: %x",
dma_reg_read(ctlr, CPDMA_RXINTSTATRAW));
dev_info(dev, "CPDMA: rxintstatmasked: %x",
dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED));
dev_info(dev, "CPDMA: rxintmaskset: %x",
dma_reg_read(ctlr, CPDMA_RXINTMASKSET));
dev_info(dev, "CPDMA: rxintmaskclear: %x",
dma_reg_read(ctlr, CPDMA_RXINTMASKCLEAR));
dev_info(dev, "CPDMA: dmaintstatraw: %x",
dma_reg_read(ctlr, CPDMA_DMAINTSTATRAW));
dev_info(dev, "CPDMA: dmaintstatmasked: %x",
dma_reg_read(ctlr, CPDMA_DMAINTSTATMASKED));
dev_info(dev, "CPDMA: dmaintmaskset: %x",
dma_reg_read(ctlr, CPDMA_DMAINTMASKSET));
dev_info(dev, "CPDMA: dmaintmaskclear: %x",
dma_reg_read(ctlr, CPDMA_DMAINTMASKCLEAR));
if (!ctlr->params.has_ext_regs) {
dev_info(dev, "CPDMA: dmacontrol: %x",
dma_reg_read(ctlr, CPDMA_DMACONTROL));
dev_info(dev, "CPDMA: dmastatus: %x",
dma_reg_read(ctlr, CPDMA_DMASTATUS));
dev_info(dev, "CPDMA: rxbuffofs: %x",
dma_reg_read(ctlr, CPDMA_RXBUFFOFS));
}
for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
if (ctlr->channels[i])
cpdma_chan_dump(ctlr->channels[i]);
spin_unlock_irqrestore(&ctlr->lock, flags);
return 0;
}
int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
{
unsigned long flags;
int ret = 0, i;
if (!ctlr)
return -EINVAL;
spin_lock_irqsave(&ctlr->lock, flags);
if (ctlr->state != CPDMA_STATE_IDLE)
cpdma_ctlr_stop(ctlr);
for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
if (ctlr->channels[i])
cpdma_chan_destroy(ctlr->channels[i]);
}
cpdma_desc_pool_destroy(ctlr->pool);
spin_unlock_irqrestore(&ctlr->lock, flags);
kfree(ctlr);
return ret;
}
int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
{
unsigned long flags;
int i, reg;
spin_lock_irqsave(&ctlr->lock, flags);
if (ctlr->state != CPDMA_STATE_ACTIVE) {
spin_unlock_irqrestore(&ctlr->lock, flags);
return -EINVAL;
}
reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
if (ctlr->channels[i])
cpdma_chan_int_ctrl(ctlr->channels[i], enable);
}
spin_unlock_irqrestore(&ctlr->lock, flags);
return 0;
}
void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr)
{
dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, 0);
}
struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
cpdma_handler_fn handler)
{
struct cpdma_chan *chan;
int ret, offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
unsigned long flags;
if (__chan_linear(chan_num) >= ctlr->num_chan)
return NULL;
ret = -ENOMEM;
chan = kzalloc(sizeof(*chan), GFP_KERNEL);
if (!chan)
goto err_chan_alloc;
spin_lock_irqsave(&ctlr->lock, flags);
ret = -EBUSY;
if (ctlr->channels[chan_num])
goto err_chan_busy;
chan->ctlr = ctlr;
chan->state = CPDMA_STATE_IDLE;
chan->chan_num = chan_num;
chan->handler = handler;
if (is_rx_chan(chan)) {
chan->hdp = ctlr->params.rxhdp + offset;
chan->cp = ctlr->params.rxcp + offset;
chan->rxfree = ctlr->params.rxfree + offset;
chan->int_set = CPDMA_RXINTMASKSET;
chan->int_clear = CPDMA_RXINTMASKCLEAR;
chan->td = CPDMA_RXTEARDOWN;
chan->dir = DMA_FROM_DEVICE;
} else {
chan->hdp = ctlr->params.txhdp + offset;
chan->cp = ctlr->params.txcp + offset;
chan->int_set = CPDMA_TXINTMASKSET;
chan->int_clear = CPDMA_TXINTMASKCLEAR;
chan->td = CPDMA_TXTEARDOWN;
chan->dir = DMA_TO_DEVICE;
}
chan->mask = BIT(chan_linear(chan));
spin_lock_init(&chan->lock);
ctlr->channels[chan_num] = chan;
spin_unlock_irqrestore(&ctlr->lock, flags);
return chan;
err_chan_busy:
spin_unlock_irqrestore(&ctlr->lock, flags);
kfree(chan);
err_chan_alloc:
return ERR_PTR(ret);
}
int cpdma_chan_destroy(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
unsigned long flags;
if (!chan)
return -EINVAL;
spin_lock_irqsave(&ctlr->lock, flags);
if (chan->state != CPDMA_STATE_IDLE)
cpdma_chan_stop(chan);
ctlr->channels[chan->chan_num] = NULL;
spin_unlock_irqrestore(&ctlr->lock, flags);
kfree(chan);
return 0;
}
int cpdma_chan_get_stats(struct cpdma_chan *chan,
struct cpdma_chan_stats *stats)
{
unsigned long flags;
if (!chan)
return -EINVAL;
spin_lock_irqsave(&chan->lock, flags);
memcpy(stats, &chan->stats, sizeof(*stats));
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
int cpdma_chan_dump(struct cpdma_chan *chan)
{
unsigned long flags;
struct device *dev = chan->ctlr->dev;
spin_lock_irqsave(&chan->lock, flags);
dev_info(dev, "channel %d (%s %d) state %s",
chan->chan_num, is_rx_chan(chan) ? "rx" : "tx",
chan_linear(chan), cpdma_state_str[chan->state]);
dev_info(dev, "\thdp: %x\n", chan_read(chan, hdp));
dev_info(dev, "\tcp: %x\n", chan_read(chan, cp));
if (chan->rxfree) {
dev_info(dev, "\trxfree: %x\n",
chan_read(chan, rxfree));
}
dev_info(dev, "\tstats head_enqueue: %d\n",
chan->stats.head_enqueue);
dev_info(dev, "\tstats tail_enqueue: %d\n",
chan->stats.tail_enqueue);
dev_info(dev, "\tstats pad_enqueue: %d\n",
chan->stats.pad_enqueue);
dev_info(dev, "\tstats misqueued: %d\n",
chan->stats.misqueued);
dev_info(dev, "\tstats desc_alloc_fail: %d\n",
chan->stats.desc_alloc_fail);
dev_info(dev, "\tstats pad_alloc_fail: %d\n",
chan->stats.pad_alloc_fail);
dev_info(dev, "\tstats runt_receive_buff: %d\n",
chan->stats.runt_receive_buff);
dev_info(dev, "\tstats runt_transmit_buff: %d\n",
chan->stats.runt_transmit_buff);
dev_info(dev, "\tstats empty_dequeue: %d\n",
chan->stats.empty_dequeue);
dev_info(dev, "\tstats busy_dequeue: %d\n",
chan->stats.busy_dequeue);
dev_info(dev, "\tstats good_dequeue: %d\n",
chan->stats.good_dequeue);
dev_info(dev, "\tstats requeue: %d\n",
chan->stats.requeue);
dev_info(dev, "\tstats teardown_dequeue: %d\n",
chan->stats.teardown_dequeue);
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
static void __cpdma_chan_submit(struct cpdma_chan *chan,
struct cpdma_desc __iomem *desc)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc __iomem *prev = chan->tail;
struct cpdma_desc_pool *pool = ctlr->pool;
dma_addr_t desc_dma;
u32 mode;
desc_dma = desc_phys(pool, desc);
/* simple case - idle channel */
if (!chan->head) {
chan->stats.head_enqueue++;
chan->head = desc;
chan->tail = desc;
if (chan->state == CPDMA_STATE_ACTIVE)
chan_write(chan, hdp, desc_dma);
return;
}
/* first chain the descriptor at the tail of the list */
desc_write(prev, hw_next, desc_dma);
chan->tail = desc;
chan->stats.tail_enqueue++;
/* next check if EOQ has been triggered already */
mode = desc_read(prev, hw_mode);
if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
(chan->state == CPDMA_STATE_ACTIVE)) {
desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
chan_write(chan, hdp, desc_dma);
chan->stats.misqueued++;
}
}
int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
int len, gfp_t gfp_mask)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc __iomem *desc;
dma_addr_t buffer;
unsigned long flags;
u32 mode;
int ret = 0;
spin_lock_irqsave(&chan->lock, flags);
if (chan->state == CPDMA_STATE_TEARDOWN) {
ret = -EINVAL;
goto unlock_ret;
}
desc = cpdma_desc_alloc(ctlr->pool, 1);
if (!desc) {
chan->stats.desc_alloc_fail++;
ret = -ENOMEM;
goto unlock_ret;
}
if (len < ctlr->params.min_packet_size) {
len = ctlr->params.min_packet_size;
chan->stats.runt_transmit_buff++;
}
buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
desc_write(desc, hw_next, 0);
desc_write(desc, hw_buffer, buffer);
desc_write(desc, hw_len, len);
desc_write(desc, hw_mode, mode | len);
desc_write(desc, sw_token, token);
desc_write(desc, sw_buffer, buffer);
desc_write(desc, sw_len, len);
__cpdma_chan_submit(chan, desc);
if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
chan_write(chan, rxfree, 1);
chan->count++;
unlock_ret:
spin_unlock_irqrestore(&chan->lock, flags);
return ret;
}
static void __cpdma_chan_free(struct cpdma_chan *chan,
struct cpdma_desc __iomem *desc,
int outlen, int status)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc_pool *pool = ctlr->pool;
dma_addr_t buff_dma;
int origlen;
void *token;
token = (void *)desc_read(desc, sw_token);
buff_dma = desc_read(desc, sw_buffer);
origlen = desc_read(desc, sw_len);
dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
cpdma_desc_free(pool, desc, 1);
(*chan->handler)(token, outlen, status);
}
static int __cpdma_chan_process(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc __iomem *desc;
int status, outlen;
struct cpdma_desc_pool *pool = ctlr->pool;
dma_addr_t desc_dma;
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
desc = chan->head;
if (!desc) {
chan->stats.empty_dequeue++;
status = -ENOENT;
goto unlock_ret;
}
desc_dma = desc_phys(pool, desc);
status = __raw_readl(&desc->hw_mode);
outlen = status & 0x7ff;
if (status & CPDMA_DESC_OWNER) {
chan->stats.busy_dequeue++;
status = -EBUSY;
goto unlock_ret;
}
status = status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE);
chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
chan_write(chan, cp, desc_dma);
chan->count--;
chan->stats.good_dequeue++;
if (status & CPDMA_DESC_EOQ) {
chan->stats.requeue++;
chan_write(chan, hdp, desc_phys(pool, chan->head));
}
spin_unlock_irqrestore(&chan->lock, flags);
__cpdma_chan_free(chan, desc, outlen, status);
return status;
unlock_ret:
spin_unlock_irqrestore(&chan->lock, flags);
return status;
}
int cpdma_chan_process(struct cpdma_chan *chan, int quota)
{
int used = 0, ret = 0;
if (chan->state != CPDMA_STATE_ACTIVE)
return -EINVAL;
while (used < quota) {
ret = __cpdma_chan_process(chan);
if (ret < 0)
break;
used++;
}
return used;
}
int cpdma_chan_start(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc_pool *pool = ctlr->pool;
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
if (chan->state != CPDMA_STATE_IDLE) {
spin_unlock_irqrestore(&chan->lock, flags);
return -EBUSY;
}
if (ctlr->state != CPDMA_STATE_ACTIVE) {
spin_unlock_irqrestore(&chan->lock, flags);
return -EINVAL;
}
dma_reg_write(ctlr, chan->int_set, chan->mask);
chan->state = CPDMA_STATE_ACTIVE;
if (chan->head) {
chan_write(chan, hdp, desc_phys(pool, chan->head));
if (chan->rxfree)
chan_write(chan, rxfree, chan->count);
}
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
int cpdma_chan_stop(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc_pool *pool = ctlr->pool;
unsigned long flags;
int ret;
unsigned long timeout;
spin_lock_irqsave(&chan->lock, flags);
if (chan->state != CPDMA_STATE_ACTIVE) {
spin_unlock_irqrestore(&chan->lock, flags);
return -EINVAL;
}
chan->state = CPDMA_STATE_TEARDOWN;
dma_reg_write(ctlr, chan->int_clear, chan->mask);
/* trigger teardown */
dma_reg_write(ctlr, chan->td, chan->chan_num);
/* wait for teardown complete */
timeout = jiffies + HZ/10; /* 100 msec */
while (time_before(jiffies, timeout)) {
u32 cp = chan_read(chan, cp);
if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
break;
cpu_relax();
}
WARN_ON(!time_before(jiffies, timeout));
chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
/* handle completed packets */
do {
ret = __cpdma_chan_process(chan);
if (ret < 0)
break;
} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
/* remaining packets haven't been tx/rx'ed, clean them up */
while (chan->head) {
struct cpdma_desc __iomem *desc = chan->head;
dma_addr_t next_dma;
next_dma = desc_read(desc, hw_next);
chan->head = desc_from_phys(pool, next_dma);
chan->stats.teardown_dequeue++;
/* issue callback without locks held */
spin_unlock_irqrestore(&chan->lock, flags);
__cpdma_chan_free(chan, desc, 0, -ENOSYS);
spin_lock_irqsave(&chan->lock, flags);
}
chan->state = CPDMA_STATE_IDLE;
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
{
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
if (chan->state != CPDMA_STATE_ACTIVE) {
spin_unlock_irqrestore(&chan->lock, flags);
return -EINVAL;
}
dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
chan->mask);
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
struct cpdma_control_info {
u32 reg;
u32 shift, mask;
int access;
#define ACCESS_RO BIT(0)
#define ACCESS_WO BIT(1)
#define ACCESS_RW (ACCESS_RO | ACCESS_WO)
};
struct cpdma_control_info controls[] = {
[CPDMA_CMD_IDLE] = {CPDMA_DMACONTROL, 3, 1, ACCESS_WO},
[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL, 4, 1, ACCESS_RW},
[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL, 2, 1, ACCESS_RW},
[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL, 1, 1, ACCESS_RW},
[CPDMA_TX_PRIO_FIXED] = {CPDMA_DMACONTROL, 0, 1, ACCESS_RW},
[CPDMA_STAT_IDLE] = {CPDMA_DMASTATUS, 31, 1, ACCESS_RO},
[CPDMA_STAT_TX_ERR_CODE] = {CPDMA_DMASTATUS, 20, 0xf, ACCESS_RW},
[CPDMA_STAT_TX_ERR_CHAN] = {CPDMA_DMASTATUS, 16, 0x7, ACCESS_RW},
[CPDMA_STAT_RX_ERR_CODE] = {CPDMA_DMASTATUS, 12, 0xf, ACCESS_RW},
[CPDMA_STAT_RX_ERR_CHAN] = {CPDMA_DMASTATUS, 8, 0x7, ACCESS_RW},
[CPDMA_RX_BUFFER_OFFSET] = {CPDMA_RXBUFFOFS, 0, 0xffff, ACCESS_RW},
};
int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
{
unsigned long flags;
struct cpdma_control_info *info = &controls[control];
int ret;
spin_lock_irqsave(&ctlr->lock, flags);
ret = -ENOTSUPP;
if (!ctlr->params.has_ext_regs)
goto unlock_ret;
ret = -EINVAL;
if (ctlr->state != CPDMA_STATE_ACTIVE)
goto unlock_ret;
ret = -ENOENT;
if (control < 0 || control >= ARRAY_SIZE(controls))
goto unlock_ret;
ret = -EPERM;
if ((info->access & ACCESS_RO) != ACCESS_RO)
goto unlock_ret;
ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
unlock_ret:
spin_unlock_irqrestore(&ctlr->lock, flags);
return ret;
}
int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
{
unsigned long flags;
struct cpdma_control_info *info = &controls[control];
int ret;
u32 val;
spin_lock_irqsave(&ctlr->lock, flags);
ret = -ENOTSUPP;
if (!ctlr->params.has_ext_regs)
goto unlock_ret;
ret = -EINVAL;
if (ctlr->state != CPDMA_STATE_ACTIVE)
goto unlock_ret;
ret = -ENOENT;
if (control < 0 || control >= ARRAY_SIZE(controls))
goto unlock_ret;
ret = -EPERM;
if ((info->access & ACCESS_WO) != ACCESS_WO)
goto unlock_ret;
val = dma_reg_read(ctlr, info->reg);
val &= ~(info->mask << info->shift);
val |= (value & info->mask) << info->shift;
dma_reg_write(ctlr, info->reg, val);
ret = 0;
unlock_ret:
spin_unlock_irqrestore(&ctlr->lock, flags);
return ret;
}