spi: Broadcom BRCMSTB, NSP, NS2 SoC bindings

Added device tree bindings documentation for BRCMSTB, NSP, NS2 iProc
SoCs supported by spi-bcm-qspi, spi-brcmstb-qspi and spi-iproc-qspi driver.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/brcm,spi-bcm-qspi.txt

+Broadcom SPI controller
+
+The Broadcom SPI controller is a SPI master found on various SOCs, including
+BRCMSTB (BCM7XXX), Cygnus, NSP and NS2. The Broadcom Master SPI hw IP consits
+of :
+ MSPI : SPI master controller can read and write to a SPI slave device
+ BSPI : Broadcom SPI in combination with the MSPI hw IP provides acceleration
+	for flash reads and be configured to do single, double, quad lane
+	io with 3-byte and 4-byte addressing support.
+
+ Supported Broadcom SoCs have one instance of MSPI+BSPI controller IP.
+ MSPI master can be used wihout BSPI. BRCMSTB SoCs have an additional instance
+ of a MSPI master without the BSPI to use with non flash slave devices that
+ use SPI protocol.
+
+Required properties:
+
+- #address-cells:
+    Must be <1>, as required by generic SPI binding.
+
+- #size-cells:
+    Must be <0>, also as required by generic SPI binding.
+
+- compatible:
+    Must be one of :
+    "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-qspi" : MSPI+BSPI on BRCMSTB SoCs
+    "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-mspi" : Second Instance of MSPI
+						   BRCMSTB  SoCs
+    "brcm,spi-bcm-qspi", "brcm,spi-nsp-qspi"     : MSPI+BSPI on Cygnus, NSP
+    "brcm,spi-bcm-qspi", "brcm,spi-ns2-qspi"     : NS2 SoCs
+
+- reg:
+    Define the bases and ranges of the associated I/O address spaces.
+    The required range is MSPI controller registers.
+
+- reg-names:
+    First name does not matter, but must be reserved for the MSPI controller
+    register range as mentioned in 'reg' above, and will typically contain
+    - "bspi_regs": BSPI register range, not required with compatible
+		   "spi-brcmstb-mspi"
+    - "mspi_regs": MSPI register range is required for compatible strings
+    - "intr_regs", "intr_status_reg" : Interrupt and status register for
+      NSP, NS2, Cygnus SoC
+
+- interrupts
+    The interrupts used by the MSPI and/or BSPI controller.
+
+- interrupt-names:
+    Names of interrupts associated with MSPI
+    - "mspi_halted" :
+    - "mspi_done": Indicates that the requested SPI operation is complete.
+    - "spi_lr_fullness_reached" : Linear read BSPI pipe full
+    - "spi_lr_session_aborted"  : Linear read BSPI pipe aborted
+    - "spi_lr_impatient" : Linear read BSPI requested when pipe empty
+    - "spi_lr_session_done" : Linear read BSPI session done
+
+- clocks:
+    A phandle to the reference clock for this block.
+
+Optional properties:
+
+
+- native-endian
+    Defined when using BE SoC and device uses BE register read/write
+
+Recommended optional m25p80 properties:
+- spi-rx-bus-width: Definition as per
+                    Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Examples:
+
+BRCMSTB SoC Example:
+
+  SPI Master (MSPI+BSPI) for SPI-NOR access:
+
+    spi@f03e3400 {
+		#address-cells = <0x1>;
+		#size-cells = <0x0>;
+		compatible = "brcm,spi-brcmstb-qspi", "brcm,spi-brcmstb-qspi";
+		reg = <0xf03e0920 0x4 0xf03e3400 0x188 0xf03e3200 0x50>;
+		reg-names = "cs_reg", "mspi", "bspi";
+		interrupts = <0x6 0x5 0x4 0x3 0x2 0x1 0x0>;
+		interrupt-parent = <0x1c>;
+		interrupt-names = "mspi_halted",
+				  "mspi_done",
+				  "spi_lr_overread",
+				  "spi_lr_session_done",
+				  "spi_lr_impatient",
+				  "spi_lr_session_aborted",
+				  "spi_lr_fullness_reached";
+
+		clocks = <&hif_spi>;
+		clock-names = "sw_spi";
+
+		m25p80@0 {
+			#size-cells = <0x2>;
+			#address-cells = <0x2>;
+			compatible = "m25p80";
+			reg = <0x0>;
+			spi-max-frequency = <0x2625a00>;
+			spi-cpol;
+			spi-cpha;
+			m25p,fast-read;
+
+			flash0.bolt@0 {
+				reg = <0x0 0x0 0x0 0x100000>;
+			};
+
+			flash0.macadr@100000 {
+				reg = <0x0 0x100000 0x0 0x10000>;
+			};
+
+			flash0.nvram@110000 {
+				reg = <0x0 0x110000 0x0 0x10000>;
+			};
+
+			flash0.kernel@120000 {
+				reg = <0x0 0x120000 0x0 0x400000>;
+			};
+
+			flash0.devtree@520000 {
+				reg = <0x0 0x520000 0x0 0x10000>;
+			};
+
+			flash0.splash@530000 {
+				reg = <0x0 0x530000 0x0 0x80000>;
+			};
+
+			flash0@0 {
+				reg = <0x0 0x0 0x0 0x4000000>;
+			};
+		};
+	};
+
+
+    MSPI master for any SPI device :
+
+	spi@f0416000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&upg_fixed>;
+		compatible = "brcm,spi-brcmstb-qspi", "brcm,spi-brcmstb-mspi";
+		reg = <0xf0416000 0x180>;
+		reg-names = "mspi";
+		interrupts = <0x14>;
+		interrupt-parent = <&irq0_aon_intc>;
+		interrupt-names = "mspi_done";
+	};
+
+iProc SoC Example:
+
+    qspi: spi@18027200 {
+	compatible = "brcm,spi-bcm-qspi", "brcm,spi-nsp-qspi";
+	reg = <0x18027200 0x184>,
+	      <0x18027000 0x124>,
+	      <0x1811c408 0x004>,
+	      <0x180273a0 0x01c>;
+	reg-names = "mspi_regs", "bspi_regs", "intr_regs", "intr_status_reg";
+	interrupts = <GIC_SPI 72 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 74 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 75 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 76 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 77 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 78 IRQ_TYPE_LEVEL_HIGH>;
+	interrupt-names =
+		     "spi_lr_fullness_reached",
+		     "spi_lr_session_aborted",
+		     "spi_lr_impatient",
+		     "spi_lr_session_done",
+		     "mspi_done",
+		     "mspi_halted";
+	clocks = <&iprocmed>;
+	clock-names = "iprocmed";
+	num-cs = <2>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+    };
+
+
+ NS2 SoC Example:
+
+	       qspi: spi@66470200 {
+		       compatible = "brcm,spi-bcm-qspi", "brcm,spi-ns2-qspi";
+		       reg = <0x66470200 0x184>,
+			     <0x66470000 0x124>,
+			     <0x67017408 0x004>,
+			     <0x664703a0 0x01c>;
+		       reg-names = "mspi", "bspi", "intr_regs",
+			"intr_status_reg";
+		       interrupts = <GIC_SPI 419 IRQ_TYPE_LEVEL_HIGH>;
+		       interrupt-names = "spi_l1_intr";
+			clocks = <&iprocmed>;
+			clock-names = "iprocmed";
+			num-cs = <2>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+	       };
+
+
+ m25p80 node for NSP, NS2
+
+	 &qspi {
+		      flash: m25p80@0 {
+		      #address-cells = <1>;
+		      #size-cells = <1>;
+		      compatible = "m25p80";
+		      reg = <0x0>;
+		      spi-max-frequency = <12500000>;
+		      m25p,fast-read;
+		      spi-cpol;
+		      spi-cpha;
+
+		      partition@0 {
+				  label = "boot";
+				  reg = <0x00000000 0x000a0000>;
+		      };
+
+		      partition@a0000 {
+				  label = "env";
+				  reg = <0x000a0000 0x00060000>;
+		      };
+
+		      partition@100000 {
+				  label = "system";
+				  reg = <0x00100000 0x00600000>;
+		      };
+
+		      partition@700000 {
+				  label = "rootfs";
+				  reg = <0x00700000 0x01900000>;
+		      };
+	};