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From 6b2bb8803f19116bad41a271f9035d4c853f4553 Mon Sep 17 00:00:00 2001
From: Matthew McClintock <mmcclint@codeaurora.org>
Date: Thu, 5 May 2016 10:07:11 -0500
Subject: [PATCH 16/37] spi: qup: allow mulitple DMA transactions per spi xfer
Much like the block mode changes, we are breaking up DMA transactions
into 64K chunks so we can reset the QUP engine.
Signed-off-by: Matthew McClintock <mmcclint@codeaurora.org>
---
drivers/spi/spi-qup.c | 120 +++++++++++++++++++++++++++++++++++--------------
1 file changed, 86 insertions(+), 34 deletions(-)
--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -566,6 +566,21 @@ static int spi_qup_io_config(struct spi_
return 0;
}
+static unsigned int spi_qup_sgl_get_size(struct scatterlist *sgl, unsigned int nents)
+{
+ struct scatterlist *sg;
+ int i;
+ unsigned int length = 0;
+
+ if (!nents)
+ return 0;
+
+ for_each_sg(sgl, sg, nents, i)
+ length += sg_dma_len(sg);
+
+ return length;
+}
+
static int spi_qup_do_dma(struct spi_device *spi, struct spi_transfer *xfer,
unsigned long timeout)
{
@@ -573,53 +588,90 @@ unsigned long timeout)
struct spi_qup *qup = spi_master_get_devdata(master);
dma_async_tx_callback rx_done = NULL, tx_done = NULL;
int ret;
+ struct scatterlist *tx_sgl, *rx_sgl;
- ret = spi_qup_io_config(spi, xfer);
- if (ret)
- return ret;
+ rx_sgl = xfer->rx_sg.sgl;
+ tx_sgl = xfer->tx_sg.sgl;
- /* before issuing the descriptors, set the QUP to run */
- ret = spi_qup_set_state(qup, QUP_STATE_RUN);
- if (ret) {
- dev_warn(qup->dev, "cannot set RUN state\n");
- return ret;
- }
+ do {
+ int rx_nents = 0, tx_nents = 0;
- if (!qup->qup_v1) {
- if (xfer->rx_buf)
- rx_done = spi_qup_dma_done;
+ if (rx_sgl) {
+ rx_nents = sg_nents_for_len(rx_sgl, SPI_MAX_XFER);
+ if (rx_nents < 0)
+ rx_nents = sg_nents(rx_sgl);
- if (xfer->tx_buf)
- tx_done = spi_qup_dma_done;
- }
+ qup->n_words = spi_qup_sgl_get_size(rx_sgl, rx_nents) /
+ qup->w_size;
+ }
- if (xfer->rx_buf) {
- ret = spi_qup_prep_sg(master, xfer->rx_sg.sgl,
- xfer->rx_sg.nents, DMA_DEV_TO_MEM,
- rx_done, &qup->done);
- if (ret)
- return ret;
+ if (tx_sgl) {
+ tx_nents = sg_nents_for_len(tx_sgl, SPI_MAX_XFER);
+ if (tx_nents < 0)
+ tx_nents = sg_nents(tx_sgl);
- dma_async_issue_pending(master->dma_rx);
- }
+ qup->n_words = spi_qup_sgl_get_size(tx_sgl, tx_nents) /
+ qup->w_size;
+ }
- if (xfer->tx_buf) {
- ret = spi_qup_prep_sg(master, xfer->tx_sg.sgl,
- xfer->tx_sg.nents, DMA_MEM_TO_DEV,
- tx_done, &qup->dma_tx_done);
+
+ ret = spi_qup_io_config(spi, xfer);
if (ret)
return ret;
- dma_async_issue_pending(master->dma_tx);
- }
+ /* before issuing the descriptors, set the QUP to run */
+ ret = spi_qup_set_state(qup, QUP_STATE_RUN);
+ if (ret) {
+ dev_warn(qup->dev, "cannot set RUN state\n");
+ return ret;
+ }
- if (xfer->rx_buf && !wait_for_completion_timeout(&qup->done, timeout))
- return -ETIMEDOUT;
+ if (!qup->qup_v1) {
+ if (rx_sgl) {
+ rx_done = spi_qup_dma_done;
+ }
- if (xfer->tx_buf && !wait_for_completion_timeout(&qup->dma_tx_done, timeout))
- ret = -ETIMEDOUT;
+ if (tx_sgl) {
+ tx_done = spi_qup_dma_done;
+ }
+ }
- return ret;
+ if (rx_sgl) {
+ ret = spi_qup_prep_sg(master, rx_sgl, rx_nents,
+ DMA_DEV_TO_MEM, rx_done,
+ &qup->done);
+ if (ret)
+ return ret;
+
+ dma_async_issue_pending(master->dma_rx);
+ }
+
+ if (tx_sgl) {
+ ret = spi_qup_prep_sg(master, tx_sgl, tx_nents,
+ DMA_MEM_TO_DEV, tx_done,
+ &qup->dma_tx_done);
+ if (ret)
+ return ret;
+
+ dma_async_issue_pending(master->dma_tx);
+ }
+
+ if (rx_sgl && !wait_for_completion_timeout(&qup->done, timeout)) {
+ pr_emerg(" rx timed out");
+ return -ETIMEDOUT;
+ }
+
+ if (tx_sgl && !wait_for_completion_timeout(&qup->dma_tx_done, timeout)) {
+ pr_emerg(" tx timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ for (; rx_sgl && rx_nents--; rx_sgl = sg_next(rx_sgl));
+ for (; tx_sgl && tx_nents--; tx_sgl = sg_next(tx_sgl));
+
+ } while (rx_sgl || tx_sgl);
+
+ return 0;
}
static int spi_qup_do_pio(struct spi_device *spi, struct spi_transfer *xfer,
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