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spi/pl022: add PrimeCell generic DMA support 

This extends the PL022 SSP/SPI driver with generic DMA engine
support using the PrimeCell DMA engine interface. Also fix up the
test code for the U300 platform.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
hifive-unleashed-5.1
Linus Walleij 2010-09-29 17:31:35 +09:00 committed by Grant Likely
parent cdbc8f042f
commit b1b6b9aa6f
2 changed files with 437 additions and 91 deletions
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522
drivers/spi/amba-pl022.c
View File

@ -27,7 +27,6 @@
/*
* TODO:
* - add timeout on polled transfers
* - add generic DMA framework support
*/
#include <linux/init.h>
@ -45,6 +44,9 @@
#include <linux/amba/pl022.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
/*
* This macro is used to define some register default values.
@ -381,6 +383,14 @@ struct pl022 {
enum ssp_reading read;
enum ssp_writing write;
u32 exp_fifo_level;
/* DMA settings */
#ifdef CONFIG_DMA_ENGINE
struct dma_chan *dma_rx_channel;
struct dma_chan *dma_tx_channel;
struct sg_table sgt_rx;
struct sg_table sgt_tx;
char *dummypage;
#endif
};
/**
@ -406,7 +416,7 @@ struct chip_data {
u16 dmacr;
u16 cpsr;
u8 n_bytes;
u8 enable_dma:1;
bool enable_dma;
enum ssp_reading read;
enum ssp_writing write;
void (*cs_control) (u32 command);
@ -763,6 +773,371 @@ static void *next_transfer(struct pl022 *pl022)
}
return STATE_DONE;
}
/*
* This DMA functionality is only compiled in if we have
* access to the generic DMA devices/DMA engine.
*/
#ifdef CONFIG_DMA_ENGINE
static void unmap_free_dma_scatter(struct pl022 *pl022)
{
/* Unmap and free the SG tables */
dma_unmap_sg(&pl022->adev->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
dma_unmap_sg(&pl022->adev->dev, pl022->sgt_rx.sgl,
pl022->sgt_rx.nents, DMA_FROM_DEVICE);
sg_free_table(&pl022->sgt_rx);
sg_free_table(&pl022->sgt_tx);
}
static void dma_callback(void *data)
{
struct pl022 *pl022 = data;
struct spi_message *msg = pl022->cur_msg;
BUG_ON(!pl022->sgt_rx.sgl);
#ifdef VERBOSE_DEBUG
/*
* Optionally dump out buffers to inspect contents, this is
* good if you want to convince yourself that the loopback
* read/write contents are the same, when adopting to a new
* DMA engine.
*/
{
struct scatterlist *sg;
unsigned int i;
dma_sync_sg_for_cpu(&pl022->adev->dev,
pl022->sgt_rx.sgl,
pl022->sgt_rx.nents,
DMA_FROM_DEVICE);
for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
print_hex_dump(KERN_ERR, "SPI RX: ",
DUMP_PREFIX_OFFSET,
16,
1,
sg_virt(sg),
sg_dma_len(sg),
1);
}
for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
print_hex_dump(KERN_ERR, "SPI TX: ",
DUMP_PREFIX_OFFSET,
16,
1,
sg_virt(sg),
sg_dma_len(sg),
1);
}
}
#endif
unmap_free_dma_scatter(pl022);
/* Update total bytes transfered */
msg->actual_length += pl022->cur_transfer->len;
if (pl022->cur_transfer->cs_change)
pl022->cur_chip->
cs_control(SSP_CHIP_DESELECT);
/* Move to next transfer */
msg->state = next_transfer(pl022);
tasklet_schedule(&pl022->pump_transfers);
}
static void setup_dma_scatter(struct pl022 *pl022,
void *buffer,
unsigned int length,
struct sg_table *sgtab)
{
struct scatterlist *sg;
int bytesleft = length;
void *bufp = buffer;
int mapbytes;
int i;
if (buffer) {
for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
/*
* If there are less bytes left than what fits
* in the current page (plus page alignment offset)
* we just feed in this, else we stuff in as much
* as we can.
*/
if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
mapbytes = bytesleft;
else
mapbytes = PAGE_SIZE - offset_in_page(bufp);
sg_set_page(sg, virt_to_page(bufp),
mapbytes, offset_in_page(bufp));
bufp += mapbytes;
bytesleft -= mapbytes;
dev_dbg(&pl022->adev->dev,
"set RX/TX target page @ %p, %d bytes, %d left\n",
bufp, mapbytes, bytesleft);
}
} else {
/* Map the dummy buffer on every page */
for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
if (bytesleft < PAGE_SIZE)
mapbytes = bytesleft;
else
mapbytes = PAGE_SIZE;
sg_set_page(sg, virt_to_page(pl022->dummypage),
mapbytes, 0);
bytesleft -= mapbytes;
dev_dbg(&pl022->adev->dev,
"set RX/TX to dummy page %d bytes, %d left\n",
mapbytes, bytesleft);
}
}
BUG_ON(bytesleft);
}
/**
* configure_dma - configures the channels for the next transfer
* @pl022: SSP driver's private data structure
*/
static int configure_dma(struct pl022 *pl022)
{
struct dma_slave_config rx_conf = {
.src_addr = SSP_DR(pl022->phybase),
.direction = DMA_FROM_DEVICE,
.src_maxburst = pl022->vendor->fifodepth >> 1,
};
struct dma_slave_config tx_conf = {
.dst_addr = SSP_DR(pl022->phybase),
.direction = DMA_TO_DEVICE,
.dst_maxburst = pl022->vendor->fifodepth >> 1,
};
unsigned int pages;
int ret;
int sglen;
struct dma_chan *rxchan = pl022->dma_rx_channel;
struct dma_chan *txchan = pl022->dma_tx_channel;
struct dma_async_tx_descriptor *rxdesc;
struct dma_async_tx_descriptor *txdesc;
dma_cookie_t cookie;
/* Check that the channels are available */
if (!rxchan || !txchan)
return -ENODEV;
switch (pl022->read) {
case READING_NULL:
/* Use the same as for writing */
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
break;
case READING_U8:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
break;
case READING_U16:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case READING_U32:
rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
}
switch (pl022->write) {
case WRITING_NULL:
/* Use the same as for reading */
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
break;
case WRITING_U8:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
break;
case WRITING_U16:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case WRITING_U32:
tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;;
break;
}
/* SPI pecularity: we need to read and write the same width */
if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
rx_conf.src_addr_width = tx_conf.dst_addr_width;
if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
tx_conf.dst_addr_width = rx_conf.src_addr_width;
BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
rxchan->device->device_control(rxchan, DMA_SLAVE_CONFIG,
(unsigned long) &rx_conf);
txchan->device->device_control(txchan, DMA_SLAVE_CONFIG,
(unsigned long) &tx_conf);
/* Create sglists for the transfers */
pages = (pl022->cur_transfer->len >> PAGE_SHIFT) + 1;
dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_KERNEL);
if (ret)
goto err_alloc_rx_sg;
ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_KERNEL);
if (ret)
goto err_alloc_tx_sg;
/* Fill in the scatterlists for the RX+TX buffers */
setup_dma_scatter(pl022, pl022->rx,
pl022->cur_transfer->len, &pl022->sgt_rx);
setup_dma_scatter(pl022, pl022->tx,
pl022->cur_transfer->len, &pl022->sgt_tx);
/* Map DMA buffers */
sglen = dma_map_sg(&pl022->adev->dev, pl022->sgt_rx.sgl,
pl022->sgt_rx.nents, DMA_FROM_DEVICE);
if (!sglen)
goto err_rx_sgmap;
sglen = dma_map_sg(&pl022->adev->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
if (!sglen)
goto err_tx_sgmap;
/* Send both scatterlists */
rxdesc = rxchan->device->device_prep_slave_sg(rxchan,
pl022->sgt_rx.sgl,
pl022->sgt_rx.nents,
DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!rxdesc)
goto err_rxdesc;
txdesc = txchan->device->device_prep_slave_sg(txchan,
pl022->sgt_tx.sgl,
pl022->sgt_tx.nents,
DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!txdesc)
goto err_txdesc;
/* Put the callback on the RX transfer only, that should finish last */
rxdesc->callback = dma_callback;
rxdesc->callback_param = pl022;
/* Submit and fire RX and TX with TX last so we're ready to read! */
cookie = rxdesc->tx_submit(rxdesc);
if (dma_submit_error(cookie))
goto err_submit_rx;
cookie = txdesc->tx_submit(txdesc);
if (dma_submit_error(cookie))
goto err_submit_tx;
rxchan->device->device_issue_pending(rxchan);
txchan->device->device_issue_pending(txchan);
return 0;
err_submit_tx:
err_submit_rx:
err_txdesc:
txchan->device->device_control(txchan, DMA_TERMINATE_ALL, 0);
err_rxdesc:
rxchan->device->device_control(rxchan, DMA_TERMINATE_ALL, 0);
dma_unmap_sg(&pl022->adev->dev, pl022->sgt_tx.sgl,
pl022->sgt_tx.nents, DMA_TO_DEVICE);
err_tx_sgmap:
dma_unmap_sg(&pl022->adev->dev, pl022->sgt_rx.sgl,
pl022->sgt_tx.nents, DMA_FROM_DEVICE);
err_rx_sgmap:
sg_free_table(&pl022->sgt_tx);
err_alloc_tx_sg:
sg_free_table(&pl022->sgt_rx);
err_alloc_rx_sg:
return -ENOMEM;
}
static int __init pl022_dma_probe(struct pl022 *pl022)
{
dma_cap_mask_t mask;
/* Try to acquire a generic DMA engine slave channel */
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
/*
* We need both RX and TX channels to do DMA, else do none
* of them.
*/
pl022->dma_rx_channel = dma_request_channel(mask,
pl022->master_info->dma_filter,
pl022->master_info->dma_rx_param);
if (!pl022->dma_rx_channel) {
dev_err(&pl022->adev->dev, "no RX DMA channel!\n");
goto err_no_rxchan;
}
pl022->dma_tx_channel = dma_request_channel(mask,
pl022->master_info->dma_filter,
pl022->master_info->dma_tx_param);
if (!pl022->dma_tx_channel) {
dev_err(&pl022->adev->dev, "no TX DMA channel!\n");
goto err_no_txchan;
}
pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!pl022->dummypage) {
dev_err(&pl022->adev->dev, "no DMA dummypage!\n");
goto err_no_dummypage;
}
dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
dma_chan_name(pl022->dma_rx_channel),
dma_chan_name(pl022->dma_tx_channel));
return 0;
err_no_dummypage:
dma_release_channel(pl022->dma_tx_channel);
err_no_txchan:
dma_release_channel(pl022->dma_rx_channel);
pl022->dma_rx_channel = NULL;
err_no_rxchan:
return -ENODEV;
}
static void terminate_dma(struct pl022 *pl022)
{
struct dma_chan *rxchan = pl022->dma_rx_channel;
struct dma_chan *txchan = pl022->dma_tx_channel;
rxchan->device->device_control(rxchan, DMA_TERMINATE_ALL, 0);
txchan->device->device_control(txchan, DMA_TERMINATE_ALL, 0);
unmap_free_dma_scatter(pl022);
}
static void pl022_dma_remove(struct pl022 *pl022)
{
if (pl022->busy)
terminate_dma(pl022);
if (pl022->dma_tx_channel)
dma_release_channel(pl022->dma_tx_channel);
if (pl022->dma_rx_channel)
dma_release_channel(pl022->dma_rx_channel);
kfree(pl022->dummypage);
}
#else
static inline int configure_dma(struct pl022 *pl022)
{
return -ENODEV;
}
static inline int pl022_dma_probe(struct pl022 *pl022)
{
return 0;
}
static inline void pl022_dma_remove(struct pl022 *pl022)
{
}
#endif
/**
* pl022_interrupt_handler - Interrupt handler for SSP controller
*
@ -794,14 +1169,17 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
if (unlikely(!irq_status))
return IRQ_NONE;
/* This handles the error code interrupts */
/*
* This handles the FIFO interrupts, the timeout
* interrupts are flatly ignored, they cannot be
* trusted.
*/
if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
/*
* Overrun interrupt - bail out since our Data has been
* corrupted
*/
dev_err(&pl022->adev->dev,
"FIFO overrun\n");
dev_err(&pl022->adev->dev, "FIFO overrun\n");
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
dev_err(&pl022->adev->dev,
"RXFIFO is full\n");
@ -896,8 +1274,8 @@ static int set_up_next_transfer(struct pl022 *pl022,
}
/**
* pump_transfers - Tasklet function which schedules next interrupt transfer
* when running in interrupt transfer mode.
* pump_transfers - Tasklet function which schedules next transfer
* when running in interrupt or DMA transfer mode.
* @data: SSP driver private data structure
*
*/
@ -954,65 +1332,23 @@ static void pump_transfers(unsigned long data)
}
/* Flush the FIFOs and let's go! */
flush(pl022);
if (pl022->cur_chip->enable_dma) {
if (configure_dma(pl022)) {
dev_dbg(&pl022->adev->dev,
"configuration of DMA failed, fall back to interrupt mode\n");
goto err_config_dma;
}
return;
}
err_config_dma:
writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
}
/**
* NOT IMPLEMENTED
* configure_dma - It configures the DMA pipes for DMA transfers
* @data: SSP driver's private data structure
*
*/
static int configure_dma(void *data)
static void do_interrupt_dma_transfer(struct pl022 *pl022)
{
struct pl022 *pl022 = data;
dev_dbg(&pl022->adev->dev, "configure DMA\n");
return -ENOTSUPP;
}
/**
* do_dma_transfer - It handles transfers of the current message
* if it is DMA xfer.
* NOT FULLY IMPLEMENTED
* @data: SSP driver's private data structure
*/
static void do_dma_transfer(void *data)
{
struct pl022 *pl022 = data;
if (configure_dma(data)) {
dev_dbg(&pl022->adev->dev, "configuration of DMA Failed!\n");
goto err_config_dma;
}
/* TODO: Implememt DMA setup of pipes here */
/* Enable target chip, set up transfer */
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
/* Error path */
pl022->cur_msg->state = STATE_ERROR;
pl022->cur_msg->status = -EIO;
giveback(pl022);
return;
}
/* Enable SSP */
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
/* TODO: Enable the DMA transfer here */
return;
err_config_dma:
pl022->cur_msg->state = STATE_ERROR;
pl022->cur_msg->status = -EIO;
giveback(pl022);
return;
}
static void do_interrupt_transfer(void *data)
{
struct pl022 *pl022 = data;
u32 irqflags = ENABLE_ALL_INTERRUPTS;
/* Enable target chip */
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
@ -1023,15 +1359,26 @@ static void do_interrupt_transfer(void *data)
giveback(pl022);
return;
}
/* If we're using DMA, set up DMA here */
if (pl022->cur_chip->enable_dma) {
/* Configure DMA transfer */
if (configure_dma(pl022)) {
dev_dbg(&pl022->adev->dev,
"configuration of DMA failed, fall back to interrupt mode\n");
goto err_config_dma;
}
/* Disable interrupts in DMA mode, IRQ from DMA controller */
irqflags = DISABLE_ALL_INTERRUPTS;
}
err_config_dma:
/* Enable SSP, turn on interrupts */
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
writew(irqflags, SSP_IMSC(pl022->virtbase));
}
static void do_polling_transfer(void *data)
static void do_polling_transfer(struct pl022 *pl022)
{
struct pl022 *pl022 = data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
@ -1101,7 +1448,7 @@ static void do_polling_transfer(void *data)
*
* This function checks if there is any spi message in the queue that
* needs processing and delegate control to appropriate function
* do_polling_transfer()/do_interrupt_transfer()/do_dma_transfer()
* do_polling_transfer()/do_interrupt_dma_transfer()
* based on the kind of the transfer
*
*/
@ -1150,10 +1497,8 @@ static void pump_messages(struct work_struct *work)
if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
do_polling_transfer(pl022);
else if (pl022->cur_chip->xfer_type == INTERRUPT_TRANSFER)
do_interrupt_transfer(pl022);
else
do_dma_transfer(pl022);
do_interrupt_dma_transfer(pl022);
}
@ -1468,23 +1813,6 @@ static int calculate_effective_freq(struct pl022 *pl022,
return 0;
}
/**
* NOT IMPLEMENTED
* process_dma_info - Processes the DMA info provided by client drivers
* @chip_info: chip info provided by client device
* @chip: Runtime state maintained by the SSP controller for each spi device
*
* This function processes and stores DMA config provided by client driver
* into the runtime state maintained by the SSP controller driver
*/
static int process_dma_info(struct pl022_config_chip *chip_info,
struct chip_data *chip)
{
dev_err(chip_info->dev,
"cannot process DMA info, DMA not implemented!\n");
return -ENOTSUPP;
}
/**
* pl022_setup - setup function registered to SPI master framework
* @spi: spi device which is requesting setup
@ -1552,8 +1880,6 @@ static int pl022_setup(struct spi_device *spi)
dev_dbg(&spi->dev, "allocated memory for controller data\n");
/* Pointer back to the SPI device */
chip_info->dev = &spi->dev;
/*
* Set controller data default values:
* Polling is supported by default
@ -1579,6 +1905,9 @@ static int pl022_setup(struct spi_device *spi)
"using user supplied controller_data settings\n");
}
/* Pointer back to the SPI device */
chip_info->dev = &spi->dev;
/*
* We can override with custom divisors, else we use the board
* frequency setting
@ -1637,9 +1966,8 @@ static int pl022_setup(struct spi_device *spi)
chip->cpsr = 0;
if ((chip_info->com_mode == DMA_TRANSFER)
&& ((pl022->master_info)->enable_dma)) {
chip->enable_dma = 1;
chip->enable_dma = true;
dev_dbg(&spi->dev, "DMA mode set in controller state\n");
status = process_dma_info(chip_info, chip);
if (status < 0)
goto err_config_params;
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
@ -1647,7 +1975,7 @@ static int pl022_setup(struct spi_device *spi)
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
SSP_DMACR_MASK_TXDMAE, 1);
} else {
chip->enable_dma = 0;
chip->enable_dma = false;
dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
SSP_DMACR_MASK_RXDMAE, 0);
@ -1773,6 +2101,7 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
if (status)
goto err_no_ioregion;
pl022->phybase = adev->res.start;
pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res));
if (pl022->virtbase == NULL) {
status = -ENOMEM;
@ -1799,6 +2128,14 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
goto err_no_irq;
}
/* Get DMA channels */
if (platform_info->enable_dma) {
status = pl022_dma_probe(pl022);
if (status != 0)
goto err_no_dma;
}
/* Initialize and start queue */
status = init_queue(pl022);
if (status != 0) {
@ -1827,6 +2164,8 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
err_start_queue:
err_init_queue:
destroy_queue(pl022);
pl022_dma_remove(pl022);
err_no_dma:
free_irq(adev->irq[0], pl022);
err_no_irq:
clk_put(pl022->clk);
@ -1857,6 +2196,7 @@ pl022_remove(struct amba_device *adev)
return status;
}
load_ssp_default_config(pl022);
pl022_dma_remove(pl022);
free_irq(adev->irq[0], pl022);
clk_disable(pl022->clk);
clk_put(pl022->clk);

6
include/linux/amba/pl022.h
View File

@ -228,6 +228,7 @@ enum ssp_chip_select {
};
struct dma_chan;
/**
* struct pl022_ssp_master - device.platform_data for SPI controller devices.
* @num_chipselect: chipselects are used to distinguish individual
@ -235,11 +236,16 @@ enum ssp_chip_select {
* each slave has a chipselect signal, but it's common that not
* every chipselect is connected to a slave.
* @enable_dma: if true enables DMA driven transfers.
* @dma_rx_param: parameter to locate an RX DMA channel.
* @dma_tx_param: parameter to locate a TX DMA channel.
*/
struct pl022_ssp_controller {
u16 bus_id;
u8 num_chipselect;
u8 enable_dma:1;
bool (*dma_filter)(struct dma_chan *chan, void *filter_param);
void *dma_rx_param;
void *dma_tx_param;
};
/**