1 files changed, 26 insertions, 25 deletions

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index 52ea1605d4c6..0b4a52b3e1dc 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -25,6 +25,11 @@
 
 #define DRIVER_NAME "rockchip-spi"
 
+#define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
+		writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
+#define ROCKCHIP_SPI_SET_BITS(reg, bits) \
+		writel_relaxed(readl_relaxed(reg) | (bits), reg)
+
 /* SPI register offsets */
 #define ROCKCHIP_SPI_CTRLR0			0x0000
 #define ROCKCHIP_SPI_CTRLR1			0x0004
@@ -149,6 +154,8 @@
  */
 #define ROCKCHIP_SPI_MAX_TRANLEN		0xffff
 
+#define ROCKCHIP_SPI_MAX_CS_NUM			2
+
 enum rockchip_ssi_type {
 	SSI_MOTO_SPI = 0,
 	SSI_TI_SSP,
@@ -193,6 +200,8 @@ struct rockchip_spi {
 	/* protect state */
 	spinlock_t lock;
 
+	bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
+
 	u32 use_dma;
 	struct sg_table tx_sg;
 	struct sg_table rx_sg;
@@ -264,37 +273,29 @@ static inline u32 rx_max(struct rockchip_spi *rs)
 
 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 {
-	u32 ser;
 	struct spi_master *master = spi->master;
 	struct rockchip_spi *rs = spi_master_get_devdata(master);
+	bool cs_asserted = !enable;
 
-	pm_runtime_get_sync(rs->dev);
+	/* Return immediately for no-op */
+	if (cs_asserted == rs->cs_asserted[spi->chip_select])
+		return;
 
-	ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
+	if (cs_asserted) {
+		/* Keep things powered as long as CS is asserted */
+		pm_runtime_get_sync(rs->dev);
 
-	/*
-	 * drivers/spi/spi.c:
-	 * static void spi_set_cs(struct spi_device *spi, bool enable)
-	 * {
-	 *		if (spi->mode & SPI_CS_HIGH)
-	 *			enable = !enable;
-	 *
-	 *		if (spi->cs_gpio >= 0)
-	 *			gpio_set_value(spi->cs_gpio, !enable);
-	 *		else if (spi->master->set_cs)
-	 *		spi->master->set_cs(spi, !enable);
-	 * }
-	 *
-	 * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
-	 */
-	if (!enable)
-		ser |= 1 << spi->chip_select;
-	else
-		ser &= ~(1 << spi->chip_select);
+		ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
+				      BIT(spi->chip_select));
+	} else {
+		ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
+				      BIT(spi->chip_select));
 
-	writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
+		/* Drop reference from when we first asserted CS */
+		pm_runtime_put(rs->dev);
+	}
 
-	pm_runtime_put_sync(rs->dev);
+	rs->cs_asserted[spi->chip_select] = cs_asserted;
 }
 
 static int rockchip_spi_prepare_message(struct spi_master *master,
@@ -739,7 +740,7 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 	master->auto_runtime_pm = true;
 	master->bus_num = pdev->id;
 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
-	master->num_chipselect = 2;
+	master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
 	master->dev.of_node = pdev->dev.of_node;
 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);