spi: zynq_spi: Add fdt support in driver

Now zynq spi driver platform data is controlled by devicetree,
enable the status by saying "okay" on respective board dts to use
the devicetree generated platdata.

Ex:
&spi1 {
	status = "okay";
};

Signed-off-by: Jagan Teki <jteki@openedev.com>
Acked-by: Simon Glass <sjg@chromium.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Tested-by: Jagan Teki <jteki@openedev.com>

arch/arm/dts/zynq-7000.dtsi

@@ -117,6 +117,7 @@
 			interrupts = <0 26 4>;
 			clocks = <&clkc 25>, <&clkc 34>;
 			clock-names = "ref_clk", "pclk";
+			spi-max-frequency = <166666700>;
 			#address-cells = <1>;
 			#size-cells = <0>;
 		};
@@ -129,6 +130,7 @@
 			interrupts = <0 49 4>;
 			clocks = <&clkc 26>, <&clkc 35>;
 			clock-names = "ref_clk", "pclk";
+			spi-max-frequency = <166666700>;
 			#address-cells = <1>;
 			#size-cells = <0>;
 		};

doc/device-tree-bindings/spi/spi-zynq.txt

@@ -11,6 +11,7 @@ Required properties:
 - clocks		: Clock phandles (see clock bindings for details).
 - clock-names		: List of input clock names - "ref_clk", "pclk"
 			  (See clock bindings for details).
+- spi-max-frequency	: Maximum SPI clocking speed of device in Hz
 
 Example:
 
@@ -22,6 +23,7 @@ Example:
 		interrupts = <0 26 4>;
 		clocks = <&clkc 25>, <&clkc 34>;
 		clock-names = "ref_clk", "pclk";
+		spi-max-frequency = <166666700>;
 		#address-cells = <1>;
 		#size-cells = <0>;
 	} ;

drivers/spi/zynq_spi.c

@@ -13,9 +13,12 @@
 #include <errno.h>
 #include <malloc.h>
 #include <spi.h>
+#include <fdtdec.h>
 #include <asm/io.h>
 #include <asm/arch/hardware.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 /* zynq spi register bit masks ZYNQ_SPI_<REG>_<BIT>_MASK */
 #define ZYNQ_SPI_CR_MSA_MASK		(1 << 15)	/* Manual start enb */
 #define ZYNQ_SPI_CR_MCS_MASK		(1 << 14)	/* Manual chip select */
@@ -63,22 +66,22 @@ struct zynq_spi_priv {
 	u32 freq;		/* required frequency */
 };
 
-static inline struct zynq_spi_regs *get_zynq_spi_regs(struct udevice *bus)
-{
-	if (bus->seq)
-		return (struct zynq_spi_regs *)ZYNQ_SPI_BASEADDR1;
-	else
-		return (struct zynq_spi_regs *)ZYNQ_SPI_BASEADDR0;
-}
-
 static int zynq_spi_ofdata_to_platdata(struct udevice *bus)
 {
 	struct zynq_spi_platdata *plat = bus->platdata;
+	const void *blob = gd->fdt_blob;
+	int node = bus->of_offset;
+
+	plat->regs = (struct zynq_spi_regs *)fdtdec_get_addr(blob, node, "reg");
 
-	plat->regs = get_zynq_spi_regs(bus);
-	plat->frequency = 166666700;
+	/* FIXME: Use 250MHz as a suitable default */
+	plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
+					250000000);
 	plat->speed_hz = plat->frequency / 2;
 
+	debug("zynq_spi_ofdata_to_platdata: regs=%p max-frequency=%d\n",
+	      plat->regs, plat->frequency);
+
 	return 0;
 }