#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/sh_dma.h>
#include <linux/spi/spi.h>
+#include <linux/spi/rspi.h>
#define RSPI_SPCR 0x00
#define RSPI_SSLP 0x01
spinlock_t lock;
struct clk *clk;
unsigned char spsr;
+
+ /* for dmaengine */
+ struct sh_dmae_slave dma_tx;
+ struct sh_dmae_slave dma_rx;
+ struct dma_chan *chan_tx;
+ struct dma_chan *chan_rx;
+ int irq;
+
+ unsigned dma_width_16bit:1;
+ unsigned dma_callbacked:1;
};
static void rspi_write8(struct rspi_data *rspi, u8 data, u16 offset)
return 0;
}
-static int rspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg,
- struct spi_transfer *t)
+static void rspi_dma_complete(void *arg)
+{
+ struct rspi_data *rspi = arg;
+
+ rspi->dma_callbacked = 1;
+ wake_up_interruptible(&rspi->wait);
+}
+
+static int rspi_dma_map_sg(struct scatterlist *sg, void *buf, unsigned len,
+ struct dma_chan *chan,
+ enum dma_transfer_direction dir)
+{
+ sg_init_table(sg, 1);
+ sg_set_buf(sg, buf, len);
+ sg_dma_len(sg) = len;
+ return dma_map_sg(chan->device->dev, sg, 1, dir);
+}
+
+static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan,
+ enum dma_transfer_direction dir)
+{
+ dma_unmap_sg(chan->device->dev, sg, 1, dir);
+}
+
+static void rspi_memory_to_8bit(void *buf, const void *data, unsigned len)
+{
+ u16 *dst = buf;
+ const u8 *src = data;
+
+ while (len) {
+ *dst++ = (u16)(*src++);
+ len--;
+ }
+}
+
+static void rspi_memory_from_8bit(void *buf, const void *data, unsigned len)
+{
+ u8 *dst = buf;
+ const u16 *src = data;
+
+ while (len) {
+ *dst++ = (u8)*src++;
+ len--;
+ }
+}
+
+static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
+{
+ struct scatterlist sg;
+ void *buf = NULL;
+ struct dma_async_tx_descriptor *desc;
+ unsigned len;
+ int ret = 0;
+
+ if (rspi->dma_width_16bit) {
+ /*
+ * If DMAC bus width is 16-bit, the driver allocates a dummy
+ * buffer. And, the driver converts original data into the
+ * DMAC data as the following format:
+ * original data: 1st byte, 2nd byte ...
+ * DMAC data: 1st byte, dummy, 2nd byte, dummy ...
+ */
+ len = t->len * 2;
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+ rspi_memory_to_8bit(buf, t->tx_buf, t->len);
+ } else {
+ len = t->len;
+ buf = (void *)t->tx_buf;
+ }
+
+ if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) {
+ ret = -EFAULT;
+ goto end_nomap;
+ }
+ desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ ret = -EIO;
+ goto end;
+ }
+
+ /*
+ * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
+ * called. So, this driver disables the IRQ while DMA transfer.
+ */
+ disable_irq(rspi->irq);
+
+ rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD, RSPI_SPCR);
+ rspi_enable_irq(rspi, SPCR_SPTIE);
+ rspi->dma_callbacked = 0;
+
+ desc->callback = rspi_dma_complete;
+ desc->callback_param = rspi;
+ dmaengine_submit(desc);
+ dma_async_issue_pending(rspi->chan_tx);
+
+ ret = wait_event_interruptible_timeout(rspi->wait,
+ rspi->dma_callbacked, HZ);
+ if (ret > 0 && rspi->dma_callbacked)
+ ret = 0;
+ else if (!ret)
+ ret = -ETIMEDOUT;
+ rspi_disable_irq(rspi, SPCR_SPTIE);
+
+ enable_irq(rspi->irq);
+
+end:
+ rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE);
+end_nomap:
+ if (rspi->dma_width_16bit)
+ kfree(buf);
+
+ return ret;
+}
+
+static void rspi_receive_init(struct rspi_data *rspi)
{
- int remain = t->len;
- u8 *data;
unsigned char spsr;
spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_OVRF)
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
RSPI_SPCR);
+}
+
+static int rspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg,
+ struct spi_transfer *t)
+{
+ int remain = t->len;
+ u8 *data;
+
+ rspi_receive_init(rspi);
data = (u8 *)t->rx_buf;
while (remain > 0) {
return 0;
}
+static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
+{
+ struct scatterlist sg, sg_dummy;
+ void *dummy = NULL, *rx_buf = NULL;
+ struct dma_async_tx_descriptor *desc, *desc_dummy;
+ unsigned len;
+ int ret = 0;
+
+ if (rspi->dma_width_16bit) {
+ /*
+ * If DMAC bus width is 16-bit, the driver allocates a dummy
+ * buffer. And, finally the driver converts the DMAC data into
+ * actual data as the following format:
+ * DMAC data: 1st byte, dummy, 2nd byte, dummy ...
+ * actual data: 1st byte, 2nd byte ...
+ */
+ len = t->len * 2;
+ rx_buf = kmalloc(len, GFP_KERNEL);
+ if (!rx_buf)
+ return -ENOMEM;
+ } else {
+ len = t->len;
+ rx_buf = t->rx_buf;
+ }
+
+ /* prepare dummy transfer to generate SPI clocks */
+ dummy = kzalloc(len, GFP_KERNEL);
+ if (!dummy) {
+ ret = -ENOMEM;
+ goto end_nomap;
+ }
+ if (!rspi_dma_map_sg(&sg_dummy, dummy, len, rspi->chan_tx,
+ DMA_TO_DEVICE)) {
+ ret = -EFAULT;
+ goto end_nomap;
+ }
+ desc_dummy = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_dummy, 1,
+ DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc_dummy) {
+ ret = -EIO;
+ goto end_dummy_mapped;
+ }
+
+ /* prepare receive transfer */
+ if (!rspi_dma_map_sg(&sg, rx_buf, len, rspi->chan_rx,
+ DMA_FROM_DEVICE)) {
+ ret = -EFAULT;
+ goto end_dummy_mapped;
+
+ }
+ desc = dmaengine_prep_slave_sg(rspi->chan_rx, &sg, 1, DMA_FROM_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ ret = -EIO;
+ goto end;
+ }
+
+ rspi_receive_init(rspi);
+
+ /*
+ * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
+ * called. So, this driver disables the IRQ while DMA transfer.
+ */
+ disable_irq(rspi->irq);
+
+ rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD, RSPI_SPCR);
+ rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
+ rspi->dma_callbacked = 0;
+
+ desc->callback = rspi_dma_complete;
+ desc->callback_param = rspi;
+ dmaengine_submit(desc);
+ dma_async_issue_pending(rspi->chan_rx);
+
+ desc_dummy->callback = NULL; /* No callback */
+ dmaengine_submit(desc_dummy);
+ dma_async_issue_pending(rspi->chan_tx);
+
+ ret = wait_event_interruptible_timeout(rspi->wait,
+ rspi->dma_callbacked, HZ);
+ if (ret > 0 && rspi->dma_callbacked)
+ ret = 0;
+ else if (!ret)
+ ret = -ETIMEDOUT;
+ rspi_disable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
+
+ enable_irq(rspi->irq);
+
+end:
+ rspi_dma_unmap_sg(&sg, rspi->chan_rx, DMA_FROM_DEVICE);
+end_dummy_mapped:
+ rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE);
+end_nomap:
+ if (rspi->dma_width_16bit) {
+ if (!ret)
+ rspi_memory_from_8bit(t->rx_buf, rx_buf, t->len);
+ kfree(rx_buf);
+ }
+ kfree(dummy);
+
+ return ret;
+}
+
+static int rspi_is_dma(struct rspi_data *rspi, struct spi_transfer *t)
+{
+ if (t->tx_buf && rspi->chan_tx)
+ return 1;
+ /* If the module receives data by DMAC, it also needs TX DMAC */
+ if (t->rx_buf && rspi->chan_tx && rspi->chan_rx)
+ return 1;
+
+ return 0;
+}
+
static void rspi_work(struct work_struct *work)
{
struct rspi_data *rspi = container_of(work, struct rspi_data, ws);
list_for_each_entry(t, &mesg->transfers, transfer_list) {
if (t->tx_buf) {
- ret = rspi_send_pio(rspi, mesg, t);
+ if (rspi_is_dma(rspi, t))
+ ret = rspi_send_dma(rspi, t);
+ else
+ ret = rspi_send_pio(rspi, mesg, t);
if (ret < 0)
goto error;
}
if (t->rx_buf) {
- ret = rspi_receive_pio(rspi, mesg, t);
+ if (rspi_is_dma(rspi, t))
+ ret = rspi_receive_dma(rspi, t);
+ else
+ ret = rspi_receive_pio(rspi, mesg, t);
if (ret < 0)
goto error;
}
return ret;
}
+static bool rspi_filter(struct dma_chan *chan, void *filter_param)
+{
+ chan->private = filter_param;
+ return true;
+}
+
+static void __devinit rspi_request_dma(struct rspi_data *rspi,
+ struct platform_device *pdev)
+{
+ struct rspi_plat_data *rspi_pd = pdev->dev.platform_data;
+ dma_cap_mask_t mask;
+
+ if (!rspi_pd)
+ return;
+
+ rspi->dma_width_16bit = rspi_pd->dma_width_16bit;
+
+ /* If the module receives data by DMAC, it also needs TX DMAC */
+ if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) {
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ rspi->dma_rx.slave_id = rspi_pd->dma_rx_id;
+ rspi->chan_rx = dma_request_channel(mask, rspi_filter,
+ &rspi->dma_rx);
+ if (rspi->chan_rx)
+ dev_info(&pdev->dev, "Use DMA when rx.\n");
+ }
+ if (rspi_pd->dma_tx_id) {
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ rspi->dma_tx.slave_id = rspi_pd->dma_tx_id;
+ rspi->chan_tx = dma_request_channel(mask, rspi_filter,
+ &rspi->dma_tx);
+ if (rspi->chan_tx)
+ dev_info(&pdev->dev, "Use DMA when tx\n");
+ }
+}
+
+static void __devexit rspi_release_dma(struct rspi_data *rspi)
+{
+ if (rspi->chan_tx)
+ dma_release_channel(rspi->chan_tx);
+ if (rspi->chan_rx)
+ dma_release_channel(rspi->chan_rx);
+}
+
static int __devexit rspi_remove(struct platform_device *pdev)
{
struct rspi_data *rspi = dev_get_drvdata(&pdev->dev);
spi_unregister_master(rspi->master);
+ rspi_release_dma(rspi);
free_irq(platform_get_irq(pdev, 0), rspi);
clk_put(rspi->clk);
iounmap(rspi->addr);
goto error3;
}
+ rspi->irq = irq;
+ rspi_request_dma(rspi, pdev);
+
ret = spi_register_master(master);
if (ret < 0) {
dev_err(&pdev->dev, "spi_register_master error.\n");
return 0;
error4:
+ rspi_release_dma(rspi);
free_irq(irq, rspi);
error3:
clk_put(rspi->clk);
projects / karo-tx-linux.git / blobdiff