[PATCHv5] spi: Convert DesignWare SPI driver to 32-bit accesses

[PATCHv5] spi: Convert DesignWare SPI driver to 32-bit accesses

[tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx]

From: Thor Thayer <tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>

Altera's Arria10 SoC requires that all write accesses of APB
peripherals be 32-bit. The DesignWare documentation indicates
this change is supported by the design.

Request for Testing:
Please test on legacy DesignWare SPI platforms. If a problem is
discovered, please reply to this thread.

Thor Thayer (1):
  spi: dw-spi: Convert 16bit accesses to 32bit accesses

 drivers/spi/spi-dw-mid.c |   10 +++++-----
 drivers/spi/spi-dw.c     |   24 ++++++++++++------------
 drivers/spi/spi-dw.h     |   10 ----------
 3 files changed, 17 insertions(+), 27 deletions(-)

-- 
1.7.9.5

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[PATCHv5] spi: dw-spi: Convert 16bit accesses to 32bit accesses

[tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx]

From: Thor Thayer <tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>

Altera's Arria10 SoC interconnect requires a 32-bit write for APB
peripherals. The current spi-dw driver uses 16-bit accesses in
some locations. This patch converts all the 16-bit reads and
writes to 32-bit reads and writes.

Additional Documentation to Support this Change:
The DW_apb_ssi databook states:
"All registers in the DW_apb_ssi are addressed at 32-bit boundaries
to remain consistent with the AHB bus. Where the physical size of
any register is less than 32-bits wide, the upper unused bits of
the 32-bit boundary are reserved. Writing to these bits has no
effect; reading from these bits returns 0." [1]

[1] Section 6.1 of dw_apb_ssi.pdf (version 3.22a)

Request for test with platforms using the DesignWare SPI IP.

Tested On:
Altera CycloneV development kit
Altera Arria10 development kit
Compile tested for build errors on x86_64 (allyesconfigs)

Signed-off-by: Thor Thayer <tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>
Reviewed-and-tested-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
r1: Use function pointers to select 16b or 32b accesses.

r2: Use 32b version of function pointers for 16b reads and
writes.

r3: Instead of function pointer solution, convert 16b reads
and writes to 32b reads and writes.

r4: Leave existing 16-bit types alone. Only change functions.

r5: Change functions to 32-bit in spi-dw-mid.c.
---
 drivers/spi/spi-dw-mid.c |   10 +++++-----
 drivers/spi/spi-dw.c     |   24 ++++++++++++------------
 drivers/spi/spi-dw.h     |   10 ----------
 3 files changed, 17 insertions(+), 27 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index d4109f6..bb1052e 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -98,12 +98,12 @@ static void mid_spi_dma_exit(struct dw_spi *dws)
 
 static irqreturn_t dma_transfer(struct dw_spi *dws)
 {
-	u16 irq_status = dw_readw(dws, DW_SPI_ISR);
+	u16 irq_status = dw_readl(dws, DW_SPI_ISR);
 
 	if (!irq_status)
 		return IRQ_NONE;
 
-	dw_readw(dws, DW_SPI_ICR);
+	dw_readl(dws, DW_SPI_ICR);
 	spi_reset_chip(dws);
 
 	dev_err(&dws->master->dev, "%s: FIFO overrun/underrun\n", __func__);
@@ -228,14 +228,14 @@ static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
 {
 	u16 dma_ctrl = 0;
 
-	dw_writew(dws, DW_SPI_DMARDLR, 0xf);
-	dw_writew(dws, DW_SPI_DMATDLR, 0x10);
+	dw_writel(dws, DW_SPI_DMARDLR, 0xf);
+	dw_writel(dws, DW_SPI_DMATDLR, 0x10);
 
 	if (xfer->tx_buf)
 		dma_ctrl |= SPI_DMA_TDMAE;
 	if (xfer->rx_buf)
 		dma_ctrl |= SPI_DMA_RDMAE;
-	dw_writew(dws, DW_SPI_DMACR, dma_ctrl);
+	dw_writel(dws, DW_SPI_DMACR, dma_ctrl);
 
 	/* Set the interrupt mask */
 	spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI);
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 0f01069..cafac22 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -157,7 +157,7 @@ static inline u32 tx_max(struct dw_spi *dws)
 	u32 tx_left, tx_room, rxtx_gap;
 
 	tx_left = (dws->tx_end - dws->tx) / dws->n_bytes;
-	tx_room = dws->fifo_len - dw_readw(dws, DW_SPI_TXFLR);
+	tx_room = dws->fifo_len - dw_readl(dws, DW_SPI_TXFLR);
 
 	/*
 	 * Another concern is about the tx/rx mismatch, we
@@ -178,7 +178,7 @@ static inline u32 rx_max(struct dw_spi *dws)
 {
 	u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes;
 
-	return min_t(u32, rx_left, dw_readw(dws, DW_SPI_RXFLR));
+	return min_t(u32, rx_left, dw_readl(dws, DW_SPI_RXFLR));
 }
 
 static void dw_writer(struct dw_spi *dws)
@@ -194,7 +194,7 @@ static void dw_writer(struct dw_spi *dws)
 			else
 				txw = *(u16 *)(dws->tx);
 		}
-		dw_writew(dws, DW_SPI_DR, txw);
+		dw_writel(dws, DW_SPI_DR, txw);
 		dws->tx += dws->n_bytes;
 	}
 }
@@ -205,7 +205,7 @@ static void dw_reader(struct dw_spi *dws)
 	u16 rxw;
 
 	while (max--) {
-		rxw = dw_readw(dws, DW_SPI_DR);
+		rxw = dw_readl(dws, DW_SPI_DR);
 		/* Care rx only if the transfer's original "rx" is not null */
 		if (dws->rx_end - dws->len) {
 			if (dws->n_bytes == 1)
@@ -228,11 +228,11 @@ static void int_error_stop(struct dw_spi *dws, const char *msg)
 
 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
 {
-	u16 irq_status = dw_readw(dws, DW_SPI_ISR);
+	u16 irq_status = dw_readl(dws, DW_SPI_ISR);
 
 	/* Error handling */
 	if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
-		dw_readw(dws, DW_SPI_ICR);
+		dw_readl(dws, DW_SPI_ICR);
 		int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun");
 		return IRQ_HANDLED;
 	}
@@ -257,7 +257,7 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id)
 {
 	struct spi_master *master = dev_id;
 	struct dw_spi *dws = spi_master_get_devdata(master);
-	u16 irq_status = dw_readw(dws, DW_SPI_ISR) & 0x3f;
+	u16 irq_status = dw_readl(dws, DW_SPI_ISR) & 0x3f;
 
 	if (!irq_status)
 		return IRQ_NONE;
@@ -354,7 +354,7 @@ static int dw_spi_transfer_one(struct spi_master *master,
 		cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
 	}
 
-	dw_writew(dws, DW_SPI_CTRL0, cr0);
+	dw_writel(dws, DW_SPI_CTRL0, cr0);
 
 	/* Check if current transfer is a DMA transaction */
 	if (master->can_dma && master->can_dma(master, spi, transfer))
@@ -375,7 +375,7 @@ static int dw_spi_transfer_one(struct spi_master *master,
 		}
 	} else if (!chip->poll_mode) {
 		txlevel = min_t(u16, dws->fifo_len / 2, dws->len / dws->n_bytes);
-		dw_writew(dws, DW_SPI_TXFLTR, txlevel);
+		dw_writel(dws, DW_SPI_TXFLTR, txlevel);
 
 		/* Set the interrupt mask */
 		imask |= SPI_INT_TXEI | SPI_INT_TXOI |
@@ -499,11 +499,11 @@ static void spi_hw_init(struct device *dev, struct dw_spi *dws)
 		u32 fifo;
 
 		for (fifo = 1; fifo < 256; fifo++) {
-			dw_writew(dws, DW_SPI_TXFLTR, fifo);
-			if (fifo != dw_readw(dws, DW_SPI_TXFLTR))
+			dw_writel(dws, DW_SPI_TXFLTR, fifo);
+			if (fifo != dw_readl(dws, DW_SPI_TXFLTR))
 				break;
 		}
-		dw_writew(dws, DW_SPI_TXFLTR, 0);
+		dw_writel(dws, DW_SPI_TXFLTR, 0);
 
 		dws->fifo_len = (fifo == 1) ? 0 : fifo;
 		dev_dbg(dev, "Detected FIFO size: %u bytes\n", dws->fifo_len);
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 41f77e2..6c91391 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -150,16 +150,6 @@ static inline void dw_writel(struct dw_spi *dws, u32 offset, u32 val)
 	__raw_writel(val, dws->regs + offset);
 }
 
-static inline u16 dw_readw(struct dw_spi *dws, u32 offset)
-{
-	return __raw_readw(dws->regs + offset);
-}
-
-static inline void dw_writew(struct dw_spi *dws, u32 offset, u16 val)
-{
-	__raw_writew(val, dws->regs + offset);
-}
-
 static inline void spi_enable_chip(struct dw_spi *dws, int enable)
 {
 	dw_writel(dws, DW_SPI_SSIENR, (enable ? 1 : 0));
-- 
1.7.9.5

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Re: [PATCHv5] spi: dw-spi: Convert 16bit accesses to 32bit accesses

[Mark Brown]

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On Thu, Mar 12, 2015 at 02:19:31PM -0500, tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org wrote:

> Altera's Arria10 SoC interconnect requires a 32-bit write for APB
> peripherals. The current spi-dw driver uses 16-bit accesses in
> some locations. This patch converts all the 16-bit reads and
> writes to 32-bit reads and writes.

Applied, thanks.

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Re: [PATCHv5] spi: Convert DesignWare SPI driver to 32-bit accesses

[Mark Brown]

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On Thu, Mar 12, 2015 at 02:19:30PM -0500, tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org wrote:
> From: Thor Thayer <tthayer-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>
> 
> Altera's Arria10 SoC requires that all write accesses of APB
> peripherals be 32-bit. The DesignWare documentation indicates
> this change is supported by the design.

Please don't send cover letters for single patches, they just add to
mail volume and often cause useful information to get lost from the
changelog - put anything that shouldn't go in the changelog after the
--- in the mail and anything else in the changelog itself.

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