[5/9] spi: amd: Refactor amd_spi_busy_wait to use readl_poll_timeout

Commit Message

Lucas Tanure Aug. 24, 2021, 10:40 a.m. UTC

This function can be replaced by readl_poll_timeout

Signed-off-by: Lucas Tanure <[e-mail]>
---
 drivers/spi/spi-amd.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

Comments

Mark Brown Aug. 24, 2021, 4:46 p.m. UTC | #1

On Tue, Aug 24, 2021 at 11:40:37AM +0100, Lucas Tanure wrote:

> -	spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
> -		    AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;

This does ioread32() while readl_poll_timeout() does a readl().  These
are almost but not quite equivalent and the differences apply to PCI
devices like this one, see device-io.rst.

Patch

diff --git a/drivers/spi/spi-amd.c b/drivers/spi/spi-amd.c
index f23467cf6acd..9476b283840b 100644
--- a/drivers/spi/spi-amd.c
+++ b/drivers/spi/spi-amd.c
@@ -12,6 +12,7 @@ 
 #include <linux/platform_device.h>
 #include <linux/delay.h>
 #include <linux/spi/spi.h>
+#include <linux/iopoll.h>
 
 #define AMD_SPI_CTRL0_REG	0x00
 #define AMD_SPI_EXEC_CMD	BIT(16)
@@ -103,24 +104,12 @@  static inline void amd_spi_set_tx_count(struct amd_spi *amd_spi, u8 tx_count)
 	amd_spi_setclear_reg8(amd_spi, AMD_SPI_TX_COUNT_REG, tx_count, 0xff);
 }
 
-static inline int amd_spi_busy_wait(struct amd_spi *amd_spi)
+static int amd_spi_busy_wait(struct amd_spi *amd_spi)
 {
-	bool spi_busy;
-	int timeout = 100000;
-
-	/* poll for SPI bus to become idle */
-	spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
-		    AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
-	while (spi_busy) {
-		usleep_range(10, 20);
-		if (timeout-- < 0)
-			return -ETIMEDOUT;
-
-		spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
-			    AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
-	}
+	u32 val;
 
-	return 0;
+	return readl_poll_timeout(amd_spi->io_remap_addr + AMD_SPI_CTRL0_REG, val,
+				 !(val & AMD_SPI_BUSY), 10, 100000);
 }
 
 static void amd_spi_execute_opcode(struct amd_spi *amd_spi)