openwrt/target/linux/ipq806x/patches-4.9/0006-spi-qup-Make-sure-mode-is-only-determined-once.patch

From 2852d6df4b60987f9248c3d36d5fe2462e6556b9 Mon Sep 17 00:00:00 2001
From: Andy Gross <andy.gross@linaro.org>
Date: Tue, 12 Apr 2016 09:11:47 -0500
Subject: [PATCH 06/37] spi: qup: Make sure mode is only determined once

This patch calculates the mode once.  All decisions on the current
transaction
is made using the mode instead of use_dma

Signed-off-by: Andy Gross <andy.gross@linaro.org>
---
 drivers/spi/spi-qup.c |   87 +++++++++++++++++++++----------------------------
 1 file changed, 37 insertions(+), 50 deletions(-)

--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -149,12 +149,20 @@ struct spi_qup {
 	int			rx_bytes;
 	int			qup_v1;
 
-	int			use_dma;
+	int			mode;
 	struct dma_slave_config	rx_conf;
 	struct dma_slave_config	tx_conf;
 };
 
 
+static inline bool spi_qup_is_dma_xfer(int mode)
+{
+	if (mode == QUP_IO_M_MODE_DMOV || mode == QUP_IO_M_MODE_BAM)
+		return true;
+
+	return false;
+}
+
 static inline bool spi_qup_is_valid_state(struct spi_qup *controller)
 {
 	u32 opstate = readl_relaxed(controller->base + QUP_STATE);
@@ -424,7 +432,7 @@ static irqreturn_t spi_qup_qup_irq(int i
 		error = -EIO;
 	}
 
-	if (!controller->use_dma) {
+	if (!spi_qup_is_dma_xfer(controller->mode)) {
 		if (opflags & QUP_OP_IN_SERVICE_FLAG)
 			spi_qup_fifo_read(controller, xfer);
 
@@ -443,34 +451,11 @@ static irqreturn_t spi_qup_qup_irq(int i
 	return IRQ_HANDLED;
 }
 
-static u32
-spi_qup_get_mode(struct spi_master *master, struct spi_transfer *xfer)
-{
-	struct spi_qup *qup = spi_master_get_devdata(master);
-	u32 mode;
-
-	qup->w_size = 4;
-
-	if (xfer->bits_per_word <= 8)
-		qup->w_size = 1;
-	else if (xfer->bits_per_word <= 16)
-		qup->w_size = 2;
-
-	qup->n_words = xfer->len / qup->w_size;
-
-	if (qup->n_words <= (qup->in_fifo_sz / sizeof(u32)))
-		mode = QUP_IO_M_MODE_FIFO;
-	else
-		mode = QUP_IO_M_MODE_BLOCK;
-
-	return mode;
-}
-
 /* set clock freq ... bits per word */
 static int spi_qup_io_config(struct spi_device *spi, struct spi_transfer *xfer)
 {
 	struct spi_qup *controller = spi_master_get_devdata(spi->master);
-	u32 config, iomode, mode, control;
+	u32 config, iomode, control;
 	int ret, n_words;
 
 	if (spi->mode & SPI_LOOP && xfer->len > controller->in_fifo_sz) {
@@ -491,23 +476,22 @@ static int spi_qup_io_config(struct spi_
 		return -EIO;
 	}
 
-	mode = spi_qup_get_mode(spi->master, xfer);
+	controller->w_size = DIV_ROUND_UP(xfer->bits_per_word, 8);
+	controller->n_words = xfer->len / controller->w_size;
 	n_words = controller->n_words;
 
-	if (mode == QUP_IO_M_MODE_FIFO) {
+	if (n_words <= (controller->in_fifo_sz / sizeof(u32))) {
+		controller->mode = QUP_IO_M_MODE_FIFO;
 		writel_relaxed(n_words, controller->base + QUP_MX_READ_CNT);
 		writel_relaxed(n_words, controller->base + QUP_MX_WRITE_CNT);
 		/* must be zero for FIFO */
 		writel_relaxed(0, controller->base + QUP_MX_INPUT_CNT);
 		writel_relaxed(0, controller->base + QUP_MX_OUTPUT_CNT);
-	} else if (!controller->use_dma) {
-		writel_relaxed(n_words, controller->base + QUP_MX_INPUT_CNT);
-		writel_relaxed(n_words, controller->base + QUP_MX_OUTPUT_CNT);
-		/* must be zero for BLOCK and BAM */
-		writel_relaxed(0, controller->base + QUP_MX_READ_CNT);
-		writel_relaxed(0, controller->base + QUP_MX_WRITE_CNT);
-	} else {
-		mode = QUP_IO_M_MODE_BAM;
+
+	} else if (spi->master->can_dma &&
+	    spi->master->can_dma(spi->master, spi, xfer) &&
+	    spi->master->cur_msg_mapped) {
+		controller->mode = QUP_IO_M_MODE_BAM;
 		writel_relaxed(0, controller->base + QUP_MX_READ_CNT);
 		writel_relaxed(0, controller->base + QUP_MX_WRITE_CNT);
 
@@ -528,19 +512,26 @@ static int spi_qup_io_config(struct spi_
 
 			writel_relaxed(0, controller->base + QUP_MX_OUTPUT_CNT);
 		}
+	} else {
+		controller->mode = QUP_IO_M_MODE_BLOCK;
+		writel_relaxed(n_words, controller->base + QUP_MX_INPUT_CNT);
+		writel_relaxed(n_words, controller->base + QUP_MX_OUTPUT_CNT);
+		/* must be zero for BLOCK and BAM */
+		writel_relaxed(0, controller->base + QUP_MX_READ_CNT);
+		writel_relaxed(0, controller->base + QUP_MX_WRITE_CNT);
 	}
 
 	iomode = readl_relaxed(controller->base + QUP_IO_M_MODES);
 	/* Set input and output transfer mode */
 	iomode &= ~(QUP_IO_M_INPUT_MODE_MASK | QUP_IO_M_OUTPUT_MODE_MASK);
 
-	if (!controller->use_dma)
+	if (!spi_qup_is_dma_xfer(controller->mode))
 		iomode &= ~(QUP_IO_M_PACK_EN | QUP_IO_M_UNPACK_EN);
 	else
 		iomode |= QUP_IO_M_PACK_EN | QUP_IO_M_UNPACK_EN;
 
-	iomode |= (mode << QUP_IO_M_OUTPUT_MODE_MASK_SHIFT);
-	iomode |= (mode << QUP_IO_M_INPUT_MODE_MASK_SHIFT);
+	iomode |= (controller->mode << QUP_IO_M_OUTPUT_MODE_MASK_SHIFT);
+	iomode |= (controller->mode << QUP_IO_M_INPUT_MODE_MASK_SHIFT);
 
 	writel_relaxed(iomode, controller->base + QUP_IO_M_MODES);
 
@@ -581,7 +572,7 @@ static int spi_qup_io_config(struct spi_
 	config |= xfer->bits_per_word - 1;
 	config |= QUP_CONFIG_SPI_MODE;
 
-	if (controller->use_dma) {
+	if (spi_qup_is_dma_xfer(controller->mode)) {
 		if (!xfer->tx_buf)
 			config |= QUP_CONFIG_NO_OUTPUT;
 		if (!xfer->rx_buf)
@@ -599,7 +590,7 @@ static int spi_qup_io_config(struct spi_
 		 * status change in BAM mode
 		 */
 
-		if (mode == QUP_IO_M_MODE_BAM)
+		if (spi_qup_is_dma_xfer(controller->mode))
 			mask = QUP_OP_IN_SERVICE_FLAG | QUP_OP_OUT_SERVICE_FLAG;
 
 		writel_relaxed(mask, controller->base + QUP_OPERATIONAL_MASK);
@@ -633,7 +624,7 @@ static int spi_qup_transfer_one(struct s
 	controller->tx_bytes = 0;
 	spin_unlock_irqrestore(&controller->lock, flags);
 
-	if (controller->use_dma)
+	if (spi_qup_is_dma_xfer(controller->mode))
 		ret = spi_qup_do_dma(master, xfer);
 	else
 		ret = spi_qup_do_pio(master, xfer);
@@ -657,7 +648,7 @@ exit:
 		ret = controller->error;
 	spin_unlock_irqrestore(&controller->lock, flags);
 
-	if (ret && controller->use_dma)
+	if (ret && spi_qup_is_dma_xfer(controller->mode))
 		spi_qup_dma_terminate(master, xfer);
 
 	return ret;
@@ -668,9 +659,7 @@ static bool spi_qup_can_dma(struct spi_m
 {
 	struct spi_qup *qup = spi_master_get_devdata(master);
 	size_t dma_align = dma_get_cache_alignment();
-	u32 mode;
-
-	qup->use_dma = 0;
+	int n_words;
 
 	if (xfer->rx_buf && (xfer->len % qup->in_blk_sz ||
 	    IS_ERR_OR_NULL(master->dma_rx) ||
@@ -682,12 +671,10 @@ static bool spi_qup_can_dma(struct spi_m
 	    !IS_ALIGNED((size_t)xfer->tx_buf, dma_align)))
 		return false;
 
-	mode = spi_qup_get_mode(master, xfer);
-	if (mode == QUP_IO_M_MODE_FIFO)
+	n_words = xfer->len / DIV_ROUND_UP(xfer->bits_per_word, 8);
+	if (n_words <= (qup->in_fifo_sz / sizeof(u32)))
 		return false;
 
-	qup->use_dma = 1;
-
 	return true;
 }