clk: sunxi: Add H3 clocks support

The H3 clock control unit is similar to the those of other sun8i family
members like the A23.

It adds a new bus gates clock similar to the simple gates, but with a
different parent clock for each single gate.
Some of the gates use the new AHB2 clock as parent, whose clock source
is muxable between AHB1 and PLL6/2. The documentation isn't totally clear
about which devices belong to AHB2 now, especially USB EHIC/OHIC, so it
is mostly based on Allwinner kernel source code.

Signed-off-by: Jens Kuske <jenskuske@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Documentation/devicetree/bindings/clock/sunxi.txt

@@ -29,6 +29,7 @@ Required properties:
 	"allwinner,sun6i-a31-ar100-clk" - for the AR100 on A31
 	"allwinner,sun9i-a80-cpus-clk" - for the CPUS on A80
 	"allwinner,sun6i-a31-ahb1-clk" - for the AHB1 clock on A31
+	"allwinner,sun8i-h3-ahb2-clk" - for the AHB2 clock on H3
 	"allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31
 	"allwinner,sun8i-a23-ahb1-gates-clk" - for the AHB1 gates on A23
 	"allwinner,sun9i-a80-ahb0-gates-clk" - for the AHB0 gates on A80
@@ -56,6 +57,7 @@ Required properties:
 	"allwinner,sun9i-a80-apb1-gates-clk" - for the APB1 gates on A80
 	"allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
 	"allwinner,sun8i-a23-apb2-gates-clk" - for the APB2 gates on A23
+	"allwinner,sun8i-h3-bus-gates-clk" - for the bus gates on H3
 	"allwinner,sun9i-a80-apbs-gates-clk" - for the APBS gates on A80
 	"allwinner,sun4i-a10-dram-gates-clk" - for the DRAM gates on A10
 	"allwinner,sun5i-a13-mbus-clk" - for the MBUS clock on A13

drivers/clk/sunxi/Makefile

@@ -10,6 +10,7 @@ obj-y += clk-a10-pll2.o
 obj-y += clk-a20-gmac.o
 obj-y += clk-mod0.o
 obj-y += clk-simple-gates.o
+obj-y += clk-sun8i-bus-gates.o
 obj-y += clk-sun8i-mbus.o
 obj-y += clk-sun9i-core.o
 obj-y += clk-sun9i-mmc.o

drivers/clk/sunxi/clk-sun8i-bus-gates.c

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2015 Jens Kuske <jenskuske@gmail.com>
+ *
+ * Based on clk-simple-gates.c, which is:
+ * Copyright 2015 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+static DEFINE_SPINLOCK(gates_lock);
+
+static void __init sun8i_h3_bus_gates_init(struct device_node *node)
+{
+	static const char * const names[] = { "ahb1", "ahb2", "apb1", "apb2" };
+	enum { AHB1, AHB2, APB1, APB2, PARENT_MAX } clk_parent;
+	const char *parents[PARENT_MAX];
+	struct clk_onecell_data *clk_data;
+	const char *clk_name;
+	struct property *prop;
+	struct resource res;
+	void __iomem *clk_reg;
+	void __iomem *reg;
+	const __be32 *p;
+	int number, i;
+	u8 clk_bit;
+	u32 index;
+
+	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
+	if (IS_ERR(reg))
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(names); i++) {
+		index = of_property_match_string(node, "clock-names",
+						 names[i]);
+		if (index < 0)
+			return;
+
+		parents[i] = of_clk_get_parent_name(node, index);
+	}
+
+	clk_data = kmalloc(sizeof(struct clk_onecell_data), GFP_KERNEL);
+	if (!clk_data)
+		goto err_unmap;
+
+	number = of_property_count_u32_elems(node, "clock-indices");
+	of_property_read_u32_index(node, "clock-indices", number - 1, &number);
+
+	clk_data->clks = kcalloc(number + 1, sizeof(struct clk *), GFP_KERNEL);
+	if (!clk_data->clks)
+		goto err_free_data;
+
+	i = 0;
+	of_property_for_each_u32(node, "clock-indices", prop, p, index) {
+		of_property_read_string_index(node, "clock-output-names",
+					      i, &clk_name);
+
+		if (index == 17 || (index >= 29 && index <= 31))
+			clk_parent = AHB2;
+		else if (index <= 63 || index >= 128)
+			clk_parent = AHB1;
+		else if (index >= 64 && index <= 95)
+			clk_parent = APB1;
+		else if (index >= 96 && index <= 127)
+			clk_parent = APB2;
+
+		clk_reg = reg + 4 * (index / 32);
+		clk_bit = index % 32;
+
+		clk_data->clks[index] = clk_register_gate(NULL, clk_name,
+							  parents[clk_parent],
+							  0, clk_reg, clk_bit,
+							  0, &gates_lock);
+		i++;
+
+		if (IS_ERR(clk_data->clks[index])) {
+			WARN_ON(true);
+			continue;
+		}
+	}
+
+	clk_data->clk_num = number + 1;
+	of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
+
+	return;
+
+err_free_data:
+	kfree(clk_data);
+err_unmap:
+	iounmap(reg);
+	of_address_to_resource(node, 0, &res);
+	release_mem_region(res.start, resource_size(&res));
+}
+
+CLK_OF_DECLARE(sun8i_h3_bus_gates, "allwinner,sun8i-h3-bus-gates-clk",
+	       sun8i_h3_bus_gates_init);

drivers/clk/sunxi/clk-sunxi.c

@@ -778,6 +778,10 @@ static const struct mux_data sun6i_a31_ahb1_mux_data __initconst = {
 	.shift = 12,
 };
 
+static const struct mux_data sun8i_h3_ahb2_mux_data __initconst = {
+	.shift = 0,
+};
+
 static void __init sunxi_mux_clk_setup(struct device_node *node,
 				       struct mux_data *data)
 {
@@ -1130,6 +1134,7 @@ static const struct of_device_id clk_divs_match[] __initconst = {
 static const struct of_device_id clk_mux_match[] __initconst = {
 	{.compatible = "allwinner,sun4i-a10-cpu-clk", .data = &sun4i_cpu_mux_data,},
 	{.compatible = "allwinner,sun6i-a31-ahb1-mux-clk", .data = &sun6i_a31_ahb1_mux_data,},
+	{.compatible = "allwinner,sun8i-h3-ahb2-clk", .data = &sun8i_h3_ahb2_mux_data,},
 	{}
 };
 
@@ -1212,6 +1217,7 @@ CLK_OF_DECLARE(sun6i_a31_clk_init, "allwinner,sun6i-a31", sun6i_init_clocks);
 CLK_OF_DECLARE(sun6i_a31s_clk_init, "allwinner,sun6i-a31s", sun6i_init_clocks);
 CLK_OF_DECLARE(sun8i_a23_clk_init, "allwinner,sun8i-a23", sun6i_init_clocks);
 CLK_OF_DECLARE(sun8i_a33_clk_init, "allwinner,sun8i-a33", sun6i_init_clocks);
+CLK_OF_DECLARE(sun8i_h3_clk_init, "allwinner,sun8i-h3", sun6i_init_clocks);
 
 static void __init sun9i_init_clocks(struct device_node *node)
 {