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spi: sirf: refactor spi transfer functions
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split sirfsoc_spi_transfer function into 3 sub-functions:
spi_sirfsoc_cmd_transfer, spi_sirfsoc_pio_transfer and
spi_sirfsoc_dma_transfer.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
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Qipan Li authored and Mark Brown committed Apr 15, 2014
1 parent bf83fd6 commit c908ef3
Showing 1 changed file with 123 additions and 109 deletions.
232 changes: 123 additions & 109 deletions drivers/spi/spi-sirf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
Expand Down Expand Up @@ -309,59 +310,51 @@ static void spi_sirfsoc_dma_fini_callback(void *data)
complete(dma_complete);
}

static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
static int spi_sirfsoc_cmd_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct sirfsoc_spi *sspi;
int timeout = t->len * 10;
sspi = spi_master_get_devdata(spi->master);
u32 cmd;

sspi->tx = t->tx_buf ? t->tx_buf : sspi->dummypage;
sspi->rx = t->rx_buf ? t->rx_buf : sspi->dummypage;
sspi->left_tx_word = sspi->left_rx_word = t->len / sspi->word_width;
reinit_completion(&sspi->rx_done);
reinit_completion(&sspi->tx_done);

writel(SIRFSOC_SPI_INT_MASK_ALL, sspi->base + SIRFSOC_SPI_INT_STATUS);

/*
* fill tx_buf into command register and wait for its completion
*/
if (sspi->tx_by_cmd) {
u32 cmd;
memcpy(&cmd, sspi->tx, t->len);

if (sspi->word_width == 1 && !(spi->mode & SPI_LSB_FIRST))
cmd = cpu_to_be32(cmd) >>
((SIRFSOC_MAX_CMD_BYTES - t->len) * 8);
if (sspi->word_width == 2 && t->len == 4 &&
(!(spi->mode & SPI_LSB_FIRST)))
cmd = ((cmd & 0xffff) << 16) | (cmd >> 16);

writel(cmd, sspi->base + SIRFSOC_SPI_CMD);
writel(SIRFSOC_SPI_FRM_END_INT_EN,
sspi->base + SIRFSOC_SPI_INT_EN);
writel(SIRFSOC_SPI_CMD_TX_EN,
sspi->base + SIRFSOC_SPI_TX_RX_EN);
sspi = spi_master_get_devdata(spi->master);
memcpy(&cmd, sspi->tx, t->len);
if (sspi->word_width == 1 && !(spi->mode & SPI_LSB_FIRST))
cmd = cpu_to_be32(cmd) >>
((SIRFSOC_MAX_CMD_BYTES - t->len) * 8);
if (sspi->word_width == 2 && t->len == 4 &&
(!(spi->mode & SPI_LSB_FIRST)))
cmd = ((cmd & 0xffff) << 16) | (cmd >> 16);
writel(cmd, sspi->base + SIRFSOC_SPI_CMD);
writel(SIRFSOC_SPI_FRM_END_INT_EN,
sspi->base + SIRFSOC_SPI_INT_EN);
writel(SIRFSOC_SPI_CMD_TX_EN,
sspi->base + SIRFSOC_SPI_TX_RX_EN);
if (wait_for_completion_timeout(&sspi->tx_done, timeout) == 0) {
dev_err(&spi->dev, "cmd transfer timeout\n");
return 0;
}

if (wait_for_completion_timeout(&sspi->tx_done, timeout) == 0) {
dev_err(&spi->dev, "transfer timeout\n");
return 0;
}
return t->len;
}

return t->len;
}
static void spi_sirfsoc_dma_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct sirfsoc_spi *sspi;
struct dma_async_tx_descriptor *rx_desc, *tx_desc;
int timeout = t->len * 10;

if (sspi->left_tx_word == 1) {
writel(readl(sspi->base + SIRFSOC_SPI_CTRL) |
SIRFSOC_SPI_ENA_AUTO_CLR,
sspi->base + SIRFSOC_SPI_CTRL);
writel(0, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
writel(0, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
} else if ((sspi->left_tx_word > 1) && (sspi->left_tx_word <
SIRFSOC_SPI_DAT_FRM_LEN_MAX)) {
sspi = spi_master_get_devdata(spi->master);
writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
writel(0, sspi->base + SIRFSOC_SPI_INT_EN);
writel(SIRFSOC_SPI_INT_MASK_ALL, sspi->base + SIRFSOC_SPI_INT_STATUS);
if (sspi->left_tx_word < SIRFSOC_SPI_DAT_FRM_LEN_MAX) {
writel(readl(sspi->base + SIRFSOC_SPI_CTRL) |
SIRFSOC_SPI_MUL_DAT_MODE |
SIRFSOC_SPI_ENA_AUTO_CLR,
SIRFSOC_SPI_ENA_AUTO_CLR | SIRFSOC_SPI_MUL_DAT_MODE,
sspi->base + SIRFSOC_SPI_CTRL);
writel(sspi->left_tx_word - 1,
sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
Expand All @@ -373,88 +366,109 @@ static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
writel(0, sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
writel(0, sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
}

writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);

if (IS_DMA_VALID(t)) {
struct dma_async_tx_descriptor *rx_desc, *tx_desc;

sspi->dst_start = dma_map_single(&spi->dev,
sspi->rx, t->len, (t->tx_buf != t->rx_buf) ?
DMA_FROM_DEVICE : DMA_BIDIRECTIONAL);
rx_desc = dmaengine_prep_slave_single(sspi->rx_chan,
sspi->dst_start, t->len, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
rx_desc->callback = spi_sirfsoc_dma_fini_callback;
rx_desc->callback_param = &sspi->rx_done;

sspi->src_start = dma_map_single(&spi->dev,
(void *)sspi->tx, t->len,
(t->tx_buf != t->rx_buf) ?
DMA_TO_DEVICE : DMA_BIDIRECTIONAL);
tx_desc = dmaengine_prep_slave_single(sspi->tx_chan,
sspi->src_start, t->len, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
tx_desc->callback = spi_sirfsoc_dma_fini_callback;
tx_desc->callback_param = &sspi->tx_done;

dmaengine_submit(tx_desc);
dmaengine_submit(rx_desc);
dma_async_issue_pending(sspi->tx_chan);
dma_async_issue_pending(sspi->rx_chan);
} else {
/* Send the first word to trigger the whole tx/rx process */
sspi->tx_word(sspi);

writel(SIRFSOC_SPI_RX_OFLOW_INT_EN |
SIRFSOC_SPI_TX_UFLOW_INT_EN |
SIRFSOC_SPI_RXFIFO_THD_INT_EN |
SIRFSOC_SPI_TXFIFO_THD_INT_EN |
SIRFSOC_SPI_FRM_END_INT_EN |
SIRFSOC_SPI_RXFIFO_FULL_INT_EN |
SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN,
sspi->base + SIRFSOC_SPI_INT_EN);
}

sspi->dst_start = dma_map_single(&spi->dev, sspi->rx, t->len,
(t->tx_buf != t->rx_buf) ?
DMA_FROM_DEVICE : DMA_BIDIRECTIONAL);
rx_desc = dmaengine_prep_slave_single(sspi->rx_chan,
sspi->dst_start, t->len, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
rx_desc->callback = spi_sirfsoc_dma_fini_callback;
rx_desc->callback_param = &sspi->rx_done;

sspi->src_start = dma_map_single(&spi->dev, (void *)sspi->tx, t->len,
(t->tx_buf != t->rx_buf) ?
DMA_TO_DEVICE : DMA_BIDIRECTIONAL);
tx_desc = dmaengine_prep_slave_single(sspi->tx_chan,
sspi->src_start, t->len, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
tx_desc->callback = spi_sirfsoc_dma_fini_callback;
tx_desc->callback_param = &sspi->tx_done;

dmaengine_submit(tx_desc);
dmaengine_submit(rx_desc);
dma_async_issue_pending(sspi->tx_chan);
dma_async_issue_pending(sspi->rx_chan);
writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN,
sspi->base + SIRFSOC_SPI_TX_RX_EN);

if (!IS_DMA_VALID(t)) { /* for PIO */
if (wait_for_completion_timeout(&sspi->rx_done, timeout) == 0)
dev_err(&spi->dev, "transfer timeout\n");
} else if (wait_for_completion_timeout(&sspi->rx_done, timeout) == 0) {
if (wait_for_completion_timeout(&sspi->rx_done, timeout) == 0) {
dev_err(&spi->dev, "transfer timeout\n");
dmaengine_terminate_all(sspi->rx_chan);
} else
sspi->left_rx_word = 0;

/*
* we only wait tx-done event if transferring by DMA. for PIO,
* we get rx data by writing tx data, so if rx is done, tx has
* done earlier
*/
if (IS_DMA_VALID(t)) {
if (wait_for_completion_timeout(&sspi->tx_done, timeout) == 0) {
dev_err(&spi->dev, "transfer timeout\n");
dmaengine_terminate_all(sspi->tx_chan);
}
if (wait_for_completion_timeout(&sspi->tx_done, timeout) == 0) {
dev_err(&spi->dev, "transfer timeout\n");
dmaengine_terminate_all(sspi->tx_chan);
}
dma_unmap_single(&spi->dev, sspi->src_start, t->len, DMA_TO_DEVICE);
dma_unmap_single(&spi->dev, sspi->dst_start, t->len, DMA_FROM_DEVICE);
/* TX, RX FIFO stop */
writel(0, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(0, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
if (sspi->left_tx_word >= SIRFSOC_SPI_DAT_FRM_LEN_MAX)
writel(0, sspi->base + SIRFSOC_SPI_TX_RX_EN);
}

if (IS_DMA_VALID(t)) {
dma_unmap_single(&spi->dev,
sspi->src_start, t->len, DMA_TO_DEVICE);
dma_unmap_single(&spi->dev,
sspi->dst_start, t->len, DMA_FROM_DEVICE);
}
static void spi_sirfsoc_pio_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct sirfsoc_spi *sspi;
int timeout = t->len * 10;

/* TX, RX FIFO stop */
sspi = spi_master_get_devdata(spi->master);
writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_RESET, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(SIRFSOC_SPI_FIFO_START, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
writel(0, sspi->base + SIRFSOC_SPI_INT_EN);
writel(SIRFSOC_SPI_INT_MASK_ALL, sspi->base + SIRFSOC_SPI_INT_STATUS);
writel(readl(sspi->base + SIRFSOC_SPI_CTRL) | SIRFSOC_SPI_MUL_DAT_MODE |
SIRFSOC_SPI_ENA_AUTO_CLR, sspi->base + SIRFSOC_SPI_CTRL);
writel(sspi->left_tx_word - 1,
sspi->base + SIRFSOC_SPI_TX_DMA_IO_LEN);
writel(sspi->left_rx_word - 1,
sspi->base + SIRFSOC_SPI_RX_DMA_IO_LEN);
sspi->tx_word(sspi);
writel(SIRFSOC_SPI_TXFIFO_EMPTY_INT_EN | SIRFSOC_SPI_TX_UFLOW_INT_EN |
SIRFSOC_SPI_RX_OFLOW_INT_EN | SIRFSOC_SPI_RXFIFO_THD_INT_EN |
SIRFSOC_SPI_TXFIFO_THD_INT_EN | SIRFSOC_SPI_FRM_END_INT_EN|
SIRFSOC_SPI_RXFIFO_FULL_INT_EN,
sspi->base + SIRFSOC_SPI_INT_EN);
writel(SIRFSOC_SPI_RX_EN | SIRFSOC_SPI_TX_EN,
sspi->base + SIRFSOC_SPI_TX_RX_EN);
if (wait_for_completion_timeout(&sspi->rx_done, timeout) == 0)
dev_err(&spi->dev, "transfer timeout\n");
writel(0, sspi->base + SIRFSOC_SPI_RXFIFO_OP);
writel(0, sspi->base + SIRFSOC_SPI_TXFIFO_OP);
writel(0, sspi->base + SIRFSOC_SPI_TX_RX_EN);
writel(0, sspi->base + SIRFSOC_SPI_INT_EN);
}

static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
{
struct sirfsoc_spi *sspi;
sspi = spi_master_get_devdata(spi->master);

sspi->tx = t->tx_buf ? t->tx_buf : sspi->dummypage;
sspi->rx = t->rx_buf ? t->rx_buf : sspi->dummypage;
sspi->left_tx_word = sspi->left_rx_word = t->len / sspi->word_width;
reinit_completion(&sspi->rx_done);
reinit_completion(&sspi->tx_done);
/*
* in the transfer, if transfer data using command register with rx_buf
* null, just fill command data into command register and wait for its
* completion.
*/
if (sspi->tx_by_cmd)
spi_sirfsoc_cmd_transfer(spi, t);
else if (IS_DMA_VALID(t))
spi_sirfsoc_dma_transfer(spi, t);
else
spi_sirfsoc_pio_transfer(spi, t);

return t->len - sspi->left_rx_word * sspi->word_width;
}
Expand Down

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