rockchip: Add SPI driver

Add a SPI driver for the Rockchip RK3288, using driver model. It should work
for other Rockchip SoCs also.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/arm/include/asm/arch-rockchip/clock.h b/arch/arm/include/asm/arch-rockchip/clock.h
index 2e5ba86..8a0376c 100644
--- a/arch/arm/include/asm/arch-rockchip/clock.h
+++ b/arch/arm/include/asm/arch-rockchip/clock.h
@@ -36,6 +36,26 @@ static inline int rk_pll_id(enum rk_clk_id clk_id)
 }
 
 /**
+ * clk_get_divisor() - Calculate the required clock divisior
+ *
+ * Given an input rate and a required output_rate, calculate the Rockchip
+ * divisor needed to achieve this.
+ *
+ * @input_rate:		Input clock rate in Hz
+ * @output_rate:	Output clock rate in Hz
+ * @return divisor register value to use
+ */
+static inline u32 clk_get_divisor(ulong input_rate, uint output_rate)
+{
+	uint clk_div;
+
+	clk_div = input_rate / output_rate;
+	clk_div = (clk_div + 1) & 0xfffe;
+
+	return clk_div;
+}
+
+/**
  * rockchip_get_cru() - get a pointer to the clock/reset unit registers
  *
  * @return pointer to registers, or -ve error on error