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>

3 files changed, 17 insertions, 27 deletions

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index d4109f6dd3c0..bb1052e748f2 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 0f0106933b52..cafac221fbf6 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 41f77e2ccf63..6c91391c1a4f 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));