spi: pxa2xx: Extract pxa2xx_spi_update() helper

There are few places that repeat the logic of "update if changed".
Extract pxa2xx_spi_update() helper to deduplicate that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510124134.24638-11-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-pxa2xx.c

@@ -200,6 +200,12 @@ static bool is_mmp2_ssp(const struct driver_data *drv_data)
 	return drv_data->ssp_type == MMP2_SSP;
 }
 
+static void pxa2xx_spi_update(const struct driver_data *drv_data, u32 reg, u32 mask, u32 value)
+{
+	if ((pxa2xx_spi_read(drv_data, reg) & mask) != value)
+		pxa2xx_spi_write(drv_data, reg, value & mask);
+}
+
 static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
 {
 	switch (drv_data->ssp_type) {
@@ -1081,19 +1087,12 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *controller,
 			dma_mapped ? "DMA" : "PIO");
 
 	if (is_lpss_ssp(drv_data)) {
-		if ((pxa2xx_spi_read(drv_data, SSIRF) & 0xff)
-		    != chip->lpss_rx_threshold)
-			pxa2xx_spi_write(drv_data, SSIRF,
-					 chip->lpss_rx_threshold);
-		if ((pxa2xx_spi_read(drv_data, SSITF) & 0xffff)
-		    != chip->lpss_tx_threshold)
-			pxa2xx_spi_write(drv_data, SSITF,
-					 chip->lpss_tx_threshold);
+		pxa2xx_spi_update(drv_data, SSIRF, GENMASK(7, 0), chip->lpss_rx_threshold);
+		pxa2xx_spi_update(drv_data, SSITF, GENMASK(15, 0), chip->lpss_tx_threshold);
 	}
 
-	if (is_quark_x1000_ssp(drv_data) &&
-	    (pxa2xx_spi_read(drv_data, DDS_RATE) != chip->dds_rate))
-		pxa2xx_spi_write(drv_data, DDS_RATE, chip->dds_rate);
+	if (is_quark_x1000_ssp(drv_data))
+		pxa2xx_spi_update(drv_data, DDS_RATE, GENMASK(23, 0), chip->dds_rate);
 
 	/* Stop the SSP */
 	if (!is_mmp2_ssp(drv_data))
@@ -1102,15 +1101,11 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *controller,
 	if (!pxa25x_ssp_comp(drv_data))
 		pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
 
+	/* first set CR1 without interrupt and service enables */
+	pxa2xx_spi_update(drv_data, SSCR1, change_mask, cr1);
+
 	/* see if we need to reload the config registers */
-	if ((pxa2xx_spi_read(drv_data, SSCR0) != cr0)
-	    || (pxa2xx_spi_read(drv_data, SSCR1) & change_mask)
-	    != (cr1 & change_mask)) {
-		/* first set CR1 without interrupt and service enables */
-		pxa2xx_spi_write(drv_data, SSCR1, cr1 & change_mask);
-		/* Update the other bits */
-		pxa2xx_spi_write(drv_data, SSCR0, cr0);
-	}
+	pxa2xx_spi_update(drv_data, SSCR0, GENMASK(31, 0), cr0);
 
 	/* Restart the SSP */
 	pxa_ssp_enable(drv_data->ssp);