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Merge branch 'topic/dma' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into HEAD

This commit is contained in:
Mark Brown 2014-02-27 18:54:00 +09:00
parent 8d19534a8d 513273538a
commit 4867147bcd
3 changed files with 312 additions and 110 deletions
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211
drivers/spi/spi-s3c64xx.c
View File

@ -381,7 +381,7 @@ static void s3c64xx_spi_dma_stop(struct s3c64xx_spi_driver_data *sdd,
#else
static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
unsigned len, dma_addr_t buf)
struct sg_table *sgt)
{
struct s3c64xx_spi_driver_data *sdd;
struct dma_slave_config config;
@ -407,8 +407,8 @@ static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
dmaengine_slave_config(dma->ch, &config);
}
desc = dmaengine_prep_slave_single(dma->ch, buf, len,
dma->direction, DMA_PREP_INTERRUPT);
desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
dma->direction, DMA_PREP_INTERRUPT);
desc->callback = s3c64xx_spi_dmacb;
desc->callback_param = dma;
@ -515,7 +515,11 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
chcfg |= S3C64XX_SPI_CH_TXCH_ON;
if (dma_mode) {
modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
#ifndef CONFIG_S3C_DMA
prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
#else
prepare_dma(&sdd->tx_dma, xfer->len, xfer->tx_dma);
#endif
} else {
switch (sdd->cur_bpw) {
case 32:
@ -547,7 +551,11 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
| S3C64XX_SPI_PACKET_CNT_EN,
regs + S3C64XX_SPI_PACKET_CNT);
#ifndef CONFIG_S3C_DMA
prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
#else
prepare_dma(&sdd->rx_dma, xfer->len, xfer->rx_dma);
#endif
}
}
@ -555,23 +563,6 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
}
static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
struct spi_device *spi)
{
if (sdd->tgl_spi != NULL) { /* If last device toggled after mssg */
if (sdd->tgl_spi != spi) { /* if last mssg on diff device */
/* Deselect the last toggled device */
if (spi->cs_gpio >= 0)
gpio_set_value(spi->cs_gpio,
spi->mode & SPI_CS_HIGH ? 0 : 1);
}
sdd->tgl_spi = NULL;
}
if (spi->cs_gpio >= 0)
gpio_set_value(spi->cs_gpio, spi->mode & SPI_CS_HIGH ? 1 : 0);
}
static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
int timeout_ms)
{
@ -593,112 +584,111 @@ static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
return RX_FIFO_LVL(status, sdd);
}
static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
struct spi_transfer *xfer, int dma_mode)
static int wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
struct spi_transfer *xfer)
{
void __iomem *regs = sdd->regs;
unsigned long val;
u32 status;
int ms;
/* millisecs to xfer 'len' bytes @ 'cur_speed' */
ms = xfer->len * 8 * 1000 / sdd->cur_speed;
ms += 10; /* some tolerance */
if (dma_mode) {
val = msecs_to_jiffies(ms) + 10;
val = wait_for_completion_timeout(&sdd->xfer_completion, val);
} else {
u32 status;
val = msecs_to_loops(ms);
do {
val = msecs_to_jiffies(ms) + 10;
val = wait_for_completion_timeout(&sdd->xfer_completion, val);
/*
* If the previous xfer was completed within timeout, then
* proceed further else return -EIO.
* DmaTx returns after simply writing data in the FIFO,
* w/o waiting for real transmission on the bus to finish.
* DmaRx returns only after Dma read data from FIFO which
* needs bus transmission to finish, so we don't worry if
* Xfer involved Rx(with or without Tx).
*/
if (val && !xfer->rx_buf) {
val = msecs_to_loops(10);
status = readl(regs + S3C64XX_SPI_STATUS);
while ((TX_FIFO_LVL(status, sdd)
|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
&& --val) {
cpu_relax();
status = readl(regs + S3C64XX_SPI_STATUS);
} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
}
if (dma_mode) {
u32 status;
/*
* If the previous xfer was completed within timeout, then
* proceed further else return -EIO.
* DmaTx returns after simply writing data in the FIFO,
* w/o waiting for real transmission on the bus to finish.
* DmaRx returns only after Dma read data from FIFO which
* needs bus transmission to finish, so we don't worry if
* Xfer involved Rx(with or without Tx).
*/
if (val && !xfer->rx_buf) {
val = msecs_to_loops(10);
status = readl(regs + S3C64XX_SPI_STATUS);
while ((TX_FIFO_LVL(status, sdd)
|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
&& --val) {
cpu_relax();
status = readl(regs + S3C64XX_SPI_STATUS);
}
}
/* If timed out while checking rx/tx status return error */
if (!val)
return -EIO;
} else {
int loops;
u32 cpy_len;
u8 *buf;
/* If it was only Tx */
if (!xfer->rx_buf) {
sdd->state &= ~TXBUSY;
return 0;
}
/*
* If the receive length is bigger than the controller fifo
* size, calculate the loops and read the fifo as many times.
* loops = length / max fifo size (calculated by using the
* fifo mask).
* For any size less than the fifo size the below code is
* executed atleast once.
*/
loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
buf = xfer->rx_buf;
do {
/* wait for data to be received in the fifo */
cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
(loops ? ms : 0));
switch (sdd->cur_bpw) {
case 32:
ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
buf, cpy_len / 4);
break;
case 16:
ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
buf, cpy_len / 2);
break;
default:
ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
buf, cpy_len);
break;
}
buf = buf + cpy_len;
} while (loops--);
sdd->state &= ~RXBUSY;
}
/* If timed out while checking rx/tx status return error */
if (!val)
return -EIO;
return 0;
}
static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
struct spi_device *spi)
static int wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
struct spi_transfer *xfer)
{
if (sdd->tgl_spi == spi)
sdd->tgl_spi = NULL;
void __iomem *regs = sdd->regs;
unsigned long val;
u32 status;
int loops;
u32 cpy_len;
u8 *buf;
int ms;
if (spi->cs_gpio >= 0)
gpio_set_value(spi->cs_gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
/* millisecs to xfer 'len' bytes @ 'cur_speed' */
ms = xfer->len * 8 * 1000 / sdd->cur_speed;
ms += 10; /* some tolerance */
val = msecs_to_loops(ms);
do {
status = readl(regs + S3C64XX_SPI_STATUS);
} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
/* If it was only Tx */
if (!xfer->rx_buf) {
sdd->state &= ~TXBUSY;
return 0;
}
/*
* If the receive length is bigger than the controller fifo
* size, calculate the loops and read the fifo as many times.
* loops = length / max fifo size (calculated by using the
* fifo mask).
* For any size less than the fifo size the below code is
* executed atleast once.
*/
loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
buf = xfer->rx_buf;
do {
/* wait for data to be received in the fifo */
cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
(loops ? ms : 0));
switch (sdd->cur_bpw) {
case 32:
ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
buf, cpy_len / 4);
break;
case 16:
ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
buf, cpy_len / 2);
break;
default:
ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
buf, cpy_len);
break;
}
buf = buf + cpy_len;
} while (loops--);
sdd->state &= ~RXBUSY;
return 0;
}
static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
@ -929,7 +919,10 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
spin_unlock_irqrestore(&sdd->lock, flags);
status = wait_for_xfer(sdd, xfer, use_dma);
if (use_dma)
status = wait_for_dma(sdd, xfer);
else
status = wait_for_pio(sdd, xfer);
if (status) {
dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
@ -1092,14 +1085,12 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
pm_runtime_put(&sdd->pdev->dev);
writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
disable_cs(sdd, spi);
return 0;
setup_exit:
pm_runtime_put(&sdd->pdev->dev);
/* setup() returns with device de-selected */
writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
disable_cs(sdd, spi);
gpio_free(cs->line);
spi_set_ctldata(spi, NULL);

180
drivers/spi/spi.c
View File

@ -24,6 +24,8 @@
#include <linux/device.h>
#include <linux/init.h>
#include <linux/cache.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
@ -580,6 +582,169 @@ static void spi_set_cs(struct spi_device *spi, bool enable)
spi->master->set_cs(spi, !enable);
}
static int spi_map_buf(struct spi_master *master, struct device *dev,
struct sg_table *sgt, void *buf, size_t len,
enum dma_data_direction dir)
{
const bool vmalloced_buf = is_vmalloc_addr(buf);
const int desc_len = vmalloced_buf ? PAGE_SIZE : master->max_dma_len;
const int sgs = DIV_ROUND_UP(len, desc_len);
struct page *vm_page;
void *sg_buf;
size_t min;
int i, ret;
ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
if (ret != 0)
return ret;
for (i = 0; i < sgs; i++) {
min = min_t(size_t, len, desc_len);
if (vmalloced_buf) {
vm_page = vmalloc_to_page(buf);
if (!vm_page) {
sg_free_table(sgt);
return -ENOMEM;
}
sg_buf = page_address(vm_page) +
((size_t)buf & ~PAGE_MASK);
} else {
sg_buf = buf;
}
sg_set_buf(&sgt->sgl[i], sg_buf, min);
buf += min;
len -= min;
}
ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
if (ret < 0) {
sg_free_table(sgt);
return ret;
}
sgt->nents = ret;
return 0;
}
static void spi_unmap_buf(struct spi_master *master, struct device *dev,
struct sg_table *sgt, enum dma_data_direction dir)
{
if (sgt->orig_nents) {
dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
sg_free_table(sgt);
}
}
static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
{
struct device *tx_dev, *rx_dev;
struct spi_transfer *xfer;
void *tmp;
unsigned int max_tx, max_rx;
int ret;
if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
max_tx = 0;
max_rx = 0;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
if ((master->flags & SPI_MASTER_MUST_TX) &&
!xfer->tx_buf)
max_tx = max(xfer->len, max_tx);
if ((master->flags & SPI_MASTER_MUST_RX) &&
!xfer->rx_buf)
max_rx = max(xfer->len, max_rx);
}
if (max_tx) {
tmp = krealloc(master->dummy_tx, max_tx,
GFP_KERNEL | GFP_DMA);
if (!tmp)
return -ENOMEM;
master->dummy_tx = tmp;
memset(tmp, 0, max_tx);
}
if (max_rx) {
tmp = krealloc(master->dummy_rx, max_rx,
GFP_KERNEL | GFP_DMA);
if (!tmp)
return -ENOMEM;
master->dummy_rx = tmp;
}
if (max_tx || max_rx) {
list_for_each_entry(xfer, &msg->transfers,
transfer_list) {
if (!xfer->tx_buf)
xfer->tx_buf = master->dummy_tx;
if (!xfer->rx_buf)
xfer->rx_buf = master->dummy_rx;
}
}
}
if (!master->can_dma)
return 0;
tx_dev = &master->dma_tx->dev->device;
rx_dev = &master->dma_rx->dev->device;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
if (!master->can_dma(master, msg->spi, xfer))
continue;
if (xfer->tx_buf != NULL) {
ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
(void *)xfer->tx_buf, xfer->len,
DMA_TO_DEVICE);
if (ret != 0)
return ret;
}
if (xfer->rx_buf != NULL) {
ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
xfer->rx_buf, xfer->len,
DMA_FROM_DEVICE);
if (ret != 0) {
spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
DMA_TO_DEVICE);
return ret;
}
}
}
master->cur_msg_mapped = true;
return 0;
}
static int spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
{
struct spi_transfer *xfer;
struct device *tx_dev, *rx_dev;
if (!master->cur_msg_mapped || !master->can_dma)
return 0;
tx_dev = &master->dma_tx->dev->device;
rx_dev = &master->dma_rx->dev->device;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
if (!master->can_dma(master, msg->spi, xfer))
continue;
spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
}
return 0;
}
/*
* spi_transfer_one_message - Default implementation of transfer_one_message()
*
@ -686,6 +851,10 @@ static void spi_pump_messages(struct kthread_work *work)
}
master->busy = false;
spin_unlock_irqrestore(&master->queue_lock, flags);
kfree(master->dummy_rx);
master->dummy_rx = NULL;
kfree(master->dummy_tx);
master->dummy_tx = NULL;
if (master->unprepare_transfer_hardware &&
master->unprepare_transfer_hardware(master))
dev_err(&master->dev,
@ -752,6 +921,13 @@ static void spi_pump_messages(struct kthread_work *work)
master->cur_msg_prepared = true;
}
ret = spi_map_msg(master, master->cur_msg);
if (ret) {
master->cur_msg->status = ret;
spi_finalize_current_message(master);
return;
}
ret = master->transfer_one_message(master, master->cur_msg);
if (ret) {
dev_err(&master->dev,
@ -841,6 +1017,8 @@ void spi_finalize_current_message(struct spi_master *master)
queue_kthread_work(&master->kworker, &master->pump_messages);
spin_unlock_irqrestore(&master->queue_lock, flags);
spi_unmap_msg(master, mesg);
if (master->cur_msg_prepared && master->unprepare_message) {
ret = master->unprepare_message(master, mesg);
if (ret) {
@ -1374,6 +1552,8 @@ int spi_register_master(struct spi_master *master)
mutex_init(&master->bus_lock_mutex);
master->bus_lock_flag = 0;
init_completion(&master->xfer_completion);
if (!master->max_dma_len)
master->max_dma_len = INT_MAX;
/* register the device, then userspace will see it.
* registration fails if the bus ID is in use.

31
include/linux/spi/spi.h
View File

@ -24,6 +24,9 @@
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/completion.h>
#include <linux/scatterlist.h>
struct dma_chan;
/*
* INTERFACES between SPI master-side drivers and SPI infrastructure.
@ -266,6 +269,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* @auto_runtime_pm: the core should ensure a runtime PM reference is held
* while the hardware is prepared, using the parent
* device for the spidev
* @max_dma_len: Maximum length of a DMA transfer for the device.
* @prepare_transfer_hardware: a message will soon arrive from the queue
* so the subsystem requests the driver to prepare the transfer hardware
* by issuing this call
@ -345,6 +349,8 @@ struct spi_master {
#define SPI_MASTER_HALF_DUPLEX BIT(0) /* can't do full duplex */
#define SPI_MASTER_NO_RX BIT(1) /* can't do buffer read */
#define SPI_MASTER_NO_TX BIT(2) /* can't do buffer write */
#define SPI_MASTER_MUST_RX BIT(3) /* requires rx */
#define SPI_MASTER_MUST_TX BIT(4) /* requires tx */
/* lock and mutex for SPI bus locking */
spinlock_t bus_lock_spinlock;
@ -386,6 +392,17 @@ struct spi_master {
/* called on release() to free memory provided by spi_master */
void (*cleanup)(struct spi_device *spi);
/*
* Used to enable core support for DMA handling, if can_dma()
* exists and returns true then the transfer will be mapped
* prior to transfer_one() being called. The driver should
* not modify or store xfer and dma_tx and dma_rx must be set
* while the device is prepared.
*/
bool (*can_dma)(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *xfer);
/*
* These hooks are for drivers that want to use the generic
* master transfer queueing mechanism. If these are used, the
@ -404,7 +421,9 @@ struct spi_master {
bool rt;
bool auto_runtime_pm;
bool cur_msg_prepared;
bool cur_msg_mapped;
struct completion xfer_completion;
size_t max_dma_len;
int (*prepare_transfer_hardware)(struct spi_master *master);
int (*transfer_one_message)(struct spi_master *master,
@ -425,6 +444,14 @@ struct spi_master {
/* gpio chip select */
int *cs_gpios;
/* DMA channels for use with core dmaengine helpers */
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
/* dummy data for full duplex devices */
void *dummy_rx;
void *dummy_tx;
};
static inline void *spi_master_get_devdata(struct spi_master *master)
@ -509,6 +536,8 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum);
* (optionally) changing the chipselect status, then starting
* the next transfer or completing this @spi_message.
* @transfer_list: transfers are sequenced through @spi_message.transfers
* @tx_sg: Scatterlist for transmit, currently not for client use
* @rx_sg: Scatterlist for receive, currently not for client use
*
* SPI transfers always write the same number of bytes as they read.
* Protocol drivers should always provide @rx_buf and/or @tx_buf.
@ -576,6 +605,8 @@ struct spi_transfer {
dma_addr_t tx_dma;
dma_addr_t rx_dma;
struct sg_table tx_sg;
struct sg_table rx_sg;
unsigned cs_change:1;
unsigned tx_nbits:3;