[PATCH v4 03/12] bus: mvebu-mbus: Add static window allocation to the DT binding

@@ -0,0 +1,203 @@
+
+* Marvell MBus controller
+
+Required properties:
+
+- compatible:	 Should be set to one of the following:
+		 marvell,armada370-mbus
+		 marvell,armadaxp-mbus
+
+- reg:		 Device's register space.
+		 Two entries are expected, see the examples below.
+		 The first one controls the devices decoding window and
+		 the second one controls the SDRAM decoding window.
+
+- address-cells: Must be '2'. The first cell for the MBus ID encoding,
+                 the second cell for the address offset within the window.
+
+- size-cells:    Must be '1'.
+
+- ranges:        Must be set up to provide a proper translation for each child.
+	         See the examples below.
+
+Example:
+
+	soc {
+		compatible = "marvell,armada370-mbus", "simple-bus";
+		reg = <0xd0020000 0x100>, <0xd0020180 0x20>;
+		#address-cells = <2>;
+		#size-cells = <1>;
+	};
+
+** MBus address decoding window specification
+
+The MBus children address space is comprised of two cells: the first one for
+the window ID and the second one for the offset within the window.
+In order to allow to describe valid and non-valid window entries, the
+following encoding is used:
+
+  0xSIAA0000 0x00oooooo
+ 
+Where:
+
+  S = 0x0 for a MBus valid window
+  S = 0xf for a non-valid window (see below)
+
+If S = 0x0, then:
+
+   I = 4-bit window target ID
+  AA = windpw attribute 
+
+If S = 0xf, then:
+
+   I = don't care
+   AA = 1 for internal register
+   AA = 2 for PCI-E
+
+Following the above encoding, for each ranges entry for a MBus valid window
+(S = 0x0), an address decoding window is allocated. On the other side,
+entries for translation that do not correspond to valid windows (S = 0xf)
+are skipped.
+
+	soc {
+		compatible = "marvell,armada370-mbus", "simple-bus";
+		reg = <0xd0020000 0x100>, <0xd0020180 0x20>;
+		#address-cells = <2>;
+		#size-cells = <1>;
+
+		ranges = <0xf0010000 0 0 0xd0000000 0x100000
+			  0x011d0000 0 0 0xfff00000 0x100000>;
+
+		bootrom {
+			compatible = "marvell,bootrom";
+			reg = <0 0x100000>;
+		};
+
+		/* other children */
+		...
+	};
+
+In the shown example, the translation entry in the 'ranges' property is what
+makes the MBus driver create a static decoding window for the corresponding 
+given child device. Note that the binding does not require child nodes to be
+present. Of course, child nodes are needed to probe the devices.
+
+Since each window is identified by its target ID and attribute ID there's
+a special macro that can be use to simplify the translation entries:
+
+#define MBUS_ID(target,attributes) (((target) << 24) | ((attributes) << 16))
+
+Using this macro, the above example would be:
+
+	soc {
+		compatible = "marvell,armada370-mbus", "simple-bus";
+		reg = <0xd0020000 0x100>, <0xd0020180 0x20>;
+		#address-cells = <2>;
+		#size-cells = <1>;
+
+		ranges = < MBUS_ID(0xf0, 0x01) 0 0 0xd0000000 0x100000
+			   MBUS_ID(0x01, 0x1d) 0 0 0xfff00000 0x100000>;
+
+		bootrom {
+			compatible = "marvell,bootrom";
+			reg = <MBUS_ID(0x01, 0x1d) 0 0x100000>;
+		};
+
+		/* other children */
+		...
+	};
+
+
+** About the window base address
+
+Remember the MBus controller allows a great deal of flexibility for choosing
+the decoding window base address. When planning the device tree layout it's
+possible to choose any address as the base address, provided of course there's
+a region large enough available, and with the required alignment.
+
+Yet in other words: there's nothing preventing us from setting a base address
+of 0xf0000000, or 0xd0000000 for the NOR device shown above, if such region is
+unused.
+
+** Window allocation policy
+
+The mbus-node ranges property defines a set of mbus windows that are expected
+to be set by the operating system and that are guaranteed to be free of overlaps
+with one another or with the system memory ranges.
+
+Each entry in the property refers to exactly one window. If the operating system
+choses to use a different set of mbus windows, it must ensure that any address
+translations performed from downstream devices are adapted accordingly.
+
+The operating system may insert additional mbus windows that do not conflict
+with the ones listed in the ranges, e.g. for mapping PCIe devices.
+As a special case, the internal register window must be set up by the boot
+loader at the address listed in the ranges property, since acess to that region
+is needed to set up the other windows.
+
+** Example
+
+See the example below, where a more complete device tree is shown:
+
+	soc {
+		compatible = "marvell,armadaxp-mbus";
+		reg = <0 0xd0020000 0 0x100>, <0 0xd0020180 0 0x20>;
+
+		ranges = <MBUS_ID(0xf0, 0x01) 0 0 0xd0000000 0x100000   /* internal-regs */
+			  MBUS_ID(0xf0, 0x02) 0xe0000000 0 0xe0000000 0x8100000  /* pcie */
+			  MBUS_ID(0x01, 0x1d) 0 0 0xfff00000 0x100000
+			  MBUS_ID(0x01, 0x2f) 0 0 0xf0000000 0x8000000>;
+
+		bootrom {
+			compatible = "marvell,bootrom";
+			reg = <MBUS_ID(0x01, 0x1d) 0 0x100000>;
+		};
+
+		devbus-bootcs {
+			status = "okay";
+			ranges = <0 MBUS_ID(0x01, 0x2f) 0 0x8000000>;
+
+			/* NOR */
+			nor {
+				compatible = "cfi-flash";
+				reg = <0 0x8000000>;
+				bank-width = <2>;
+			};
+		};
+
+		pcie-controller {
+			compatible = "marvell,armada-xp-pcie";
+			status = "okay";
+			device_type = "pci";
+
+			#address-cells = <3>;
+			#size-cells = <2>;
+
+			ranges =
+			       <0x82000000 0 0x40000 MBUS_ID(0xf0, 0x01) 0x40000 0 0x00002000   /* Port 0.0 registers */
+				0x82000000 0 0x42000 MBUS_ID(0xf0, 0x01) 0x42000 0 0x00002000   /* Port 2.0 registers */
+				0x82000000 0 0x44000 MBUS_ID(0xf0, 0x01) 0x44000 0 0x00002000   /* Port 0.1 registers */
+				0x82000000 0 0x48000 MBUS_ID(0xf0, 0x01) 0x48000 0 0x00002000   /* Port 0.2 registers */
+				0x82000000 0 0x4c000 MBUS_ID(0xf0, 0x01) 0x4c000 0 0x00002000   /* Port 0.3 registers */
+				0x82000000 0 0x80000 MBUS_ID(0xf0, 0x01) 0x80000 0 0x00002000   /* Port 1.0 registers */
+				0x82000000 0 0x82000 MBUS_ID(0xf0, 0x01) 0x82000 0 0x00002000   /* Port 3.0 registers */
+				0x82000000 0 0xe0000000 MBUS_ID(0xf0, 0x02) 0xe0000000 0 0x08000000   /* non-prefetchable memory */
+				0x81000000 0 0 MBUS_ID(0xf0, 0x02) 0xe8000000 0 0x00100000>; /* downstream I/O */
+
+			pcie at 1,0 {
+				/* Port 0, Lane 0 */
+				status = "okay";
+			};
+		};
+
+		internal-regs {
+			compatible = "simple-bus";
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0 MBUS_ID(0xf0, 0x01) 0 0x100000>;
+
+			interrupt-controller at 20000 {
+			      reg = <0x20a00 0x2d0>, <0x21070 0x58>;
+			};
+		};
+	};

@@ -885,6 +885,121 @@ int __init mvebu_mbus_init(const char *soc, phys_addr_t mbuswins_phys_base,
 }
 
 #ifdef CONFIG_OF
+/*
+ * The window IDs in the ranges DT property have the following format:
+ *  - bits 28 to 31: MBus custom field
+ *  - bits 24 to 27: window target ID
+ *  - bits 16 to 23: window attribute ID
+ *  - bits  0 to 15: unused
+ */
+#define CUSTOM(id) (((id) & 0xF0000000) >> 24)
+#define TARGET(id) (((id) & 0x0F000000) >> 24)
+#define ATTR(id)   (((id) & 0x00FF0000) >> 16)
+
+static int __init mbus_dt_setup_win(struct mvebu_mbus_state *mbus,
+				    u32 base, u32 size,
+				    u8 target, u8 attr)
+{
+	const struct mvebu_mbus_mapping *map = mbus->soc->map;
+	const char *name;
+	int i;
+
+	/* Search for a suitable window in the existing mappings */
+	for (i = 0; map[i].name; i++)
+		if (map[i].target == target &&
+		    map[i].attr == (attr & map[i].attrmask))
+			break;
+
+	name = map[i].name;
+	if (!name) {
+		pr_err("window 0x%x:0x%x is unknown, skipping\n",
+		       target, attr);
+		return -EINVAL;
+	}
+
+	if (!mvebu_mbus_window_conflicts(mbus, base, size, target, attr)) {
+		pr_err("cannot add window '%s', conflicts with another window\n",
+		       name);
+		return -EBUSY;
+	}
+
+	if (mvebu_mbus_alloc_window(mbus, base, size, MVEBU_MBUS_NO_REMAP,
+				    target, attr)) {
+		pr_err("cannot add window '%s', too many windows\n",
+		       name);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static int __init
+mbus_parse_ranges(struct device_node *node,
+		  int *addr_cells, int *c_addr_cells, int *c_size_cells,
+		  int *cell_count, const __be32 **ranges_start,
+		  const __be32 **ranges_end)
+{
+	const __be32 *prop;
+	int ranges_len, tuple_len;
+
+	*addr_cells = of_n_addr_cells(node);
+
+	prop = of_get_property(node, "#address-cells", NULL);
+	*c_addr_cells = be32_to_cpup(prop);
+
+	prop = of_get_property(node, "#size-cells", NULL);
+	*c_size_cells = be32_to_cpup(prop);
+
+	*cell_count = *addr_cells + *c_addr_cells + *c_size_cells;
+	tuple_len = (*cell_count) * sizeof(__be32);
+
+	*ranges_start = of_get_property(node, "ranges", &ranges_len);
+	*ranges_end = *ranges_start + ranges_len / sizeof(__be32);
+
+	if (*ranges_start == NULL || ranges_len % tuple_len) {
+		pr_warn("malformed ranges entry '%s'\n", node->name);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int __init mbus_dt_setup(struct mvebu_mbus_state *mbus,
+				struct device_node *np)
+{
+	int addr_cells, c_addr_cells, c_size_cells;
+	int i, ret, cell_count;
+	const __be32 *r, *ranges_start, *ranges_end;
+
+	ret = mbus_parse_ranges(np, &addr_cells, &c_addr_cells,
+				&c_size_cells, &cell_count,
+				&ranges_start, &ranges_end);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0, r = ranges_start; r < ranges_end; r += cell_count, i++) {
+		u32 windowid, base, size;
+		u8 target, attr;
+
+		/*
+		 * An entry with a non-zero custom field do not
+		 * correspond to a static window, so skip it.
+		 */
+		windowid = of_read_number(r, 1);
+		if (CUSTOM(windowid))
+			continue;
+
+		target = TARGET(windowid);
+		attr = ATTR(windowid);
+
+		base = of_read_number(r + c_addr_cells, addr_cells);
+		size = of_read_number(r + c_addr_cells + addr_cells,
+				      c_size_cells);
+		ret = mbus_dt_setup_win(mbus, base, size, target, attr);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+
 int __init mvebu_mbus_dt_init(void)
 {
 	struct resource mbuswins_res, sdramwins_res;

@@ -916,6 +1031,10 @@ int __init mvebu_mbus_dt_init(void)
 				     resource_size(&mbuswins_res),
 				     sdramwins_res.start,
 				     resource_size(&sdramwins_res));
-	return ret;
+	if (ret)
+		return ret;
+
+	/* Setup statically declared windows in the DT */
+	return mbus_dt_setup(&mbus_state, np);
 }
 #endif