spi: Fixes for v5.5

A small collection of fixes here, one to make the newly added PTP
 timestamping code more accurate, a few driver fixes and a fix for the
 core DT binding to document the fact that we support eight wire buses.
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Merge tag 'spi-fix-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A small collection of fixes here, one to make the newly added PTP
  timestamping code more accurate, a few driver fixes and a fix for the
  core DT binding to document the fact that we support eight wire buses"

* tag 'spi-fix-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: Document Octal mode as valid SPI bus width
  spi: spi-dw: Add lock protect dw_spi rx/tx to prevent concurrent calls
  spi: spi-fsl-dspi: Fix 16-bit word order in 32-bit XSPI mode
  spi: Don't look at TX buffer for PTP system timestamping
  spi: uniphier: Fix FIFO threshold

Documentation/devicetree/bindings/spi/spi-controller.yaml

@@ -111,7 +111,7 @@ patternProperties:
       spi-rx-bus-width:
         allOf:
           - $ref: /schemas/types.yaml#/definitions/uint32
-          - enum: [ 1, 2, 4 ]
+          - enum: [ 1, 2, 4, 8 ]
           - default: 1
         description:
           Bus width to the SPI bus used for MISO.
@@ -123,7 +123,7 @@ patternProperties:
       spi-tx-bus-width:
         allOf:
           - $ref: /schemas/types.yaml#/definitions/uint32
-          - enum: [ 1, 2, 4 ]
+          - enum: [ 1, 2, 4, 8 ]
           - default: 1
         description:
           Bus width to the SPI bus used for MOSI.

drivers/spi/spi-dw.c

@@ -172,9 +172,11 @@ static inline u32 rx_max(struct dw_spi *dws)
 
 static void dw_writer(struct dw_spi *dws)
 {
-	u32 max = tx_max(dws);
+	u32 max;
 	u16 txw = 0;
 
+	spin_lock(&dws->buf_lock);
+	max = tx_max(dws);
 	while (max--) {
 		/* Set the tx word if the transfer's original "tx" is not null */
 		if (dws->tx_end - dws->len) {
@@ -186,13 +188,16 @@ static void dw_writer(struct dw_spi *dws)
 		dw_write_io_reg(dws, DW_SPI_DR, txw);
 		dws->tx += dws->n_bytes;
 	}
+	spin_unlock(&dws->buf_lock);
 }
 
 static void dw_reader(struct dw_spi *dws)
 {
-	u32 max = rx_max(dws);
+	u32 max;
 	u16 rxw;
 
+	spin_lock(&dws->buf_lock);
+	max = rx_max(dws);
 	while (max--) {
 		rxw = dw_read_io_reg(dws, DW_SPI_DR);
 		/* Care rx only if the transfer's original "rx" is not null */
@@ -204,6 +209,7 @@ static void dw_reader(struct dw_spi *dws)
 		}
 		dws->rx += dws->n_bytes;
 	}
+	spin_unlock(&dws->buf_lock);
 }
 
 static void int_error_stop(struct dw_spi *dws, const char *msg)
@@ -276,18 +282,20 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 {
 	struct dw_spi *dws = spi_controller_get_devdata(master);
 	struct chip_data *chip = spi_get_ctldata(spi);
+	unsigned long flags;
 	u8 imask = 0;
 	u16 txlevel = 0;
 	u32 cr0;
 	int ret;
 
 	dws->dma_mapped = 0;
-
+	spin_lock_irqsave(&dws->buf_lock, flags);
 	dws->tx = (void *)transfer->tx_buf;
 	dws->tx_end = dws->tx + transfer->len;
 	dws->rx = transfer->rx_buf;
 	dws->rx_end = dws->rx + transfer->len;
 	dws->len = transfer->len;
+	spin_unlock_irqrestore(&dws->buf_lock, flags);
 
 	spi_enable_chip(dws, 0);
 
@@ -471,6 +479,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 	dws->type = SSI_MOTO_SPI;
 	dws->dma_inited = 0;
 	dws->dma_addr = (dma_addr_t)(dws->paddr + DW_SPI_DR);
+	spin_lock_init(&dws->buf_lock);
 
 	spi_controller_set_devdata(master, dws);
 

drivers/spi/spi-dw.h

@@ -119,6 +119,7 @@ struct dw_spi {
 	size_t			len;
 	void			*tx;
 	void			*tx_end;
+	spinlock_t		buf_lock;
 	void			*rx;
 	void			*rx_end;
 	int			dma_mapped;

drivers/spi/spi-fsl-dspi.c

@@ -185,6 +185,7 @@ struct fsl_dspi {
 	struct spi_transfer			*cur_transfer;
 	struct spi_message			*cur_msg;
 	struct chip_data			*cur_chip;
+	size_t					progress;
 	size_t					len;
 	const void				*tx;
 	void					*rx;
@@ -586,21 +587,14 @@ static void dspi_tcfq_write(struct fsl_dspi *dspi)
 	dspi->tx_cmd |= SPI_PUSHR_CMD_CTCNT;
 
 	if (dspi->devtype_data->xspi_mode && dspi->bits_per_word > 16) {
-		/* Write two TX FIFO entries first, and then the corresponding
-		 * CMD FIFO entry.
+		/* Write the CMD FIFO entry first, and then the two
+		 * corresponding TX FIFO entries.
 		 */
 		u32 data = dspi_pop_tx(dspi);
 
-		if (dspi->cur_chip->ctar_val & SPI_CTAR_LSBFE) {
-			/* LSB */
-			tx_fifo_write(dspi, data & 0xFFFF);
-			tx_fifo_write(dspi, data >> 16);
-		} else {
-			/* MSB */
-			tx_fifo_write(dspi, data >> 16);
-			tx_fifo_write(dspi, data & 0xFFFF);
-		}
 		cmd_fifo_write(dspi);
+		tx_fifo_write(dspi, data & 0xFFFF);
+		tx_fifo_write(dspi, data >> 16);
 	} else {
 		/* Write one entry to both TX FIFO and CMD FIFO
 		 * simultaneously.
@@ -658,7 +652,7 @@ static int dspi_rxtx(struct fsl_dspi *dspi)
 	u32 spi_tcr;
 
 	spi_take_timestamp_post(dspi->ctlr, dspi->cur_transfer,
-				dspi->tx - dspi->bytes_per_word, !dspi->irq);
+				dspi->progress, !dspi->irq);
 
 	/* Get transfer counter (in number of SPI transfers). It was
 	 * reset to 0 when transfer(s) were started.
@@ -667,6 +661,7 @@ static int dspi_rxtx(struct fsl_dspi *dspi)
 	spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr);
 	/* Update total number of bytes that were transferred */
 	msg->actual_length += spi_tcnt * dspi->bytes_per_word;
+	dspi->progress += spi_tcnt;
 
 	trans_mode = dspi->devtype_data->trans_mode;
 	if (trans_mode == DSPI_EOQ_MODE)
@@ -679,7 +674,7 @@ static int dspi_rxtx(struct fsl_dspi *dspi)
 		return 0;
 
 	spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer,
-			       dspi->tx, !dspi->irq);
+			       dspi->progress, !dspi->irq);
 
 	if (trans_mode == DSPI_EOQ_MODE)
 		dspi_eoq_write(dspi);
@@ -768,6 +763,7 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr,
 		dspi->rx = transfer->rx_buf;
 		dspi->rx_end = dspi->rx + transfer->len;
 		dspi->len = transfer->len;
+		dspi->progress = 0;
 		/* Validated transfer specific frame size (defaults applied) */
 		dspi->bits_per_word = transfer->bits_per_word;
 		if (transfer->bits_per_word <= 8)
@@ -789,7 +785,7 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr,
 				     SPI_CTARE_DTCP(1));
 
 		spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer,
-				       dspi->tx, !dspi->irq);
+				       dspi->progress, !dspi->irq);
 
 		trans_mode = dspi->devtype_data->trans_mode;
 		switch (trans_mode) {

drivers/spi/spi-uniphier.c

@@ -290,25 +290,32 @@ static void uniphier_spi_recv(struct uniphier_spi_priv *priv)
 	}
 }
 
-static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv)
+static void uniphier_spi_set_fifo_threshold(struct uniphier_spi_priv *priv,
+					    unsigned int threshold)
 {
-	unsigned int fifo_threshold, fill_bytes;
 	u32 val;
 
-	fifo_threshold = DIV_ROUND_UP(priv->rx_bytes,
-				bytes_per_word(priv->bits_per_word));
-	fifo_threshold = min(fifo_threshold, SSI_FIFO_DEPTH);
-
-	fill_bytes = fifo_threshold - (priv->rx_bytes - priv->tx_bytes);
-
-	/* set fifo threshold */
 	val = readl(priv->base + SSI_FC);
 	val &= ~(SSI_FC_TXFTH_MASK | SSI_FC_RXFTH_MASK);
-	val |= FIELD_PREP(SSI_FC_TXFTH_MASK, fifo_threshold);
-	val |= FIELD_PREP(SSI_FC_RXFTH_MASK, fifo_threshold);
+	val |= FIELD_PREP(SSI_FC_TXFTH_MASK, SSI_FIFO_DEPTH - threshold);
+	val |= FIELD_PREP(SSI_FC_RXFTH_MASK, threshold);
 	writel(val, priv->base + SSI_FC);
+}
 
-	while (fill_bytes--)
+static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv)
+{
+	unsigned int fifo_threshold, fill_words;
+	unsigned int bpw = bytes_per_word(priv->bits_per_word);
+
+	fifo_threshold = DIV_ROUND_UP(priv->rx_bytes, bpw);
+	fifo_threshold = min(fifo_threshold, SSI_FIFO_DEPTH);
+
+	uniphier_spi_set_fifo_threshold(priv, fifo_threshold);
+
+	fill_words = fifo_threshold -
+		DIV_ROUND_UP(priv->rx_bytes - priv->tx_bytes, bpw);
+
+	while (fill_words--)
 		uniphier_spi_send(priv);
 }
 

drivers/spi/spi.c

@@ -1499,8 +1499,7 @@ static void spi_pump_messages(struct kthread_work *work)
  *			    advances its @tx buffer pointer monotonically.
  * @ctlr: Pointer to the spi_controller structure of the driver
  * @xfer: Pointer to the transfer being timestamped
- * @tx: Pointer to the current word within the xfer->tx_buf that the driver is
- *	preparing to transmit right now.
+ * @progress: How many words (not bytes) have been transferred so far
  * @irqs_off: If true, will disable IRQs and preemption for the duration of the
  *	      transfer, for less jitter in time measurement. Only compatible
  *	      with PIO drivers. If true, must follow up with
@@ -1510,21 +1509,19 @@ static void spi_pump_messages(struct kthread_work *work)
  */
 void spi_take_timestamp_pre(struct spi_controller *ctlr,
 			    struct spi_transfer *xfer,
-			    const void *tx, bool irqs_off)
+			    size_t progress, bool irqs_off)
 {
-	u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8);
-
 	if (!xfer->ptp_sts)
 		return;
 
 	if (xfer->timestamped_pre)
 		return;
 
-	if (tx < (xfer->tx_buf + xfer->ptp_sts_word_pre * bytes_per_word))
+	if (progress < xfer->ptp_sts_word_pre)
 		return;
 
 	/* Capture the resolution of the timestamp */
-	xfer->ptp_sts_word_pre = (tx - xfer->tx_buf) / bytes_per_word;
+	xfer->ptp_sts_word_pre = progress;
 
 	xfer->timestamped_pre = true;
 
@@ -1546,23 +1543,20 @@ EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
  *			     timestamped.
  * @ctlr: Pointer to the spi_controller structure of the driver
  * @xfer: Pointer to the transfer being timestamped
- * @tx: Pointer to the current word within the xfer->tx_buf that the driver has
- *	just transmitted.
+ * @progress: How many words (not bytes) have been transferred so far
  * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
  */
 void spi_take_timestamp_post(struct spi_controller *ctlr,
 			     struct spi_transfer *xfer,
-			     const void *tx, bool irqs_off)
+			     size_t progress, bool irqs_off)
 {
-	u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8);
-
 	if (!xfer->ptp_sts)
 		return;
 
 	if (xfer->timestamped_post)
 		return;
 
-	if (tx < (xfer->tx_buf + xfer->ptp_sts_word_post * bytes_per_word))
+	if (progress < xfer->ptp_sts_word_post)
 		return;
 
 	ptp_read_system_postts(xfer->ptp_sts);
@@ -1573,7 +1567,7 @@ void spi_take_timestamp_post(struct spi_controller *ctlr,
 	}
 
 	/* Capture the resolution of the timestamp */
-	xfer->ptp_sts_word_post = (tx - xfer->tx_buf) / bytes_per_word;
+	xfer->ptp_sts_word_post = progress;
 
 	xfer->timestamped_post = true;
 }

include/linux/spi/spi.h

@@ -689,10 +689,10 @@ extern void spi_finalize_current_transfer(struct spi_controller *ctlr);
 /* Helper calls for driver to timestamp transfer */
 void spi_take_timestamp_pre(struct spi_controller *ctlr,
 			    struct spi_transfer *xfer,
-			    const void *tx, bool irqs_off);
+			    size_t progress, bool irqs_off);
 void spi_take_timestamp_post(struct spi_controller *ctlr,
 			     struct spi_transfer *xfer,
-			     const void *tx, bool irqs_off);
+			     size_t progress, bool irqs_off);
 
 /* the spi driver core manages memory for the spi_controller classdev */
 extern struct spi_controller *__spi_alloc_controller(struct device *host,