spi: dw-spi: Convert 16bit accesses to 32bit accesses

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@opensource.altera.com>
Reviewed-and-tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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 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 @@
 {
 	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);