clk: sunxi: Add PLL3 clock

The A10 SoCs and relatives have a PLL controller to drive the PLL3 and
PLL7, clocked from a 3MHz oscillator, that drives the display related
clocks (GPU, display engine, TCON, etc.)

Add a driver for it.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Documentation/devicetree/bindings/clock/sunxi.txt

@@ -10,6 +10,7 @@ Required properties:
 	"allwinner,sun4i-a10-pll1-clk" - for the main PLL clock and PLL4
 	"allwinner,sun6i-a31-pll1-clk" - for the main PLL clock on A31
 	"allwinner,sun8i-a23-pll1-clk" - for the main PLL clock on A23
+	"allwinner,sun4i-a10-pll3-clk" - for the video PLL clock on A10
 	"allwinner,sun9i-a80-pll4-clk" - for the peripheral PLLs on A80
 	"allwinner,sun4i-a10-pll5-clk" - for the PLL5 clock
 	"allwinner,sun4i-a10-pll6-clk" - for the PLL6 clock

drivers/clk/sunxi/Makefile

@@ -11,6 +11,7 @@ obj-y += clk-a10-ve.o
 obj-y += clk-a20-gmac.o
 obj-y += clk-mod0.o
 obj-y += clk-simple-gates.o
+obj-y += clk-sun4i-pll3.o
 obj-y += clk-sun8i-bus-gates.o
 obj-y += clk-sun8i-mbus.o
 obj-y += clk-sun9i-core.o

drivers/clk/sunxi/clk-sun4i-pll3.c

+/*
+ * 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-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define SUN4I_A10_PLL3_GATE_BIT	31
+#define SUN4I_A10_PLL3_DIV_WIDTH	7
+#define SUN4I_A10_PLL3_DIV_SHIFT	0
+
+static DEFINE_SPINLOCK(sun4i_a10_pll3_lock);
+
+static void __init sun4i_a10_pll3_setup(struct device_node *node)
+{
+	const char *clk_name = node->name, *parent;
+	struct clk_multiplier *mult;
+	struct clk_gate *gate;
+	struct resource res;
+	void __iomem *reg;
+	struct clk *clk;
+	int ret;
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+	parent = of_clk_get_parent_name(node, 0);
+
+	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
+	if (IS_ERR(reg)) {
+		pr_err("%s: Could not map the clock registers\n", clk_name);
+		return;
+	}
+
+	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		goto err_unmap;
+
+	gate->reg = reg;
+	gate->bit_idx = SUN4I_A10_PLL3_GATE_BIT;
+	gate->lock = &sun4i_a10_pll3_lock;
+
+	mult = kzalloc(sizeof(*mult), GFP_KERNEL);
+	if (!mult)
+		goto err_free_gate;
+
+	mult->reg = reg;
+	mult->shift = SUN4I_A10_PLL3_DIV_SHIFT;
+	mult->width = SUN4I_A10_PLL3_DIV_WIDTH;
+	mult->lock = &sun4i_a10_pll3_lock;
+
+	clk = clk_register_composite(NULL, clk_name,
+				     &parent, 1,
+				     NULL, NULL,
+				     &mult->hw, &clk_multiplier_ops,
+				     &gate->hw, &clk_gate_ops,
+				     0);
+	if (IS_ERR(clk)) {
+		pr_err("%s: Couldn't register the clock\n", clk_name);
+		goto err_free_mult;
+	}
+
+	ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	if (ret) {
+		pr_err("%s: Couldn't register DT provider\n",
+		       clk_name);
+		goto err_clk_unregister;
+	}
+
+	return;
+
+err_clk_unregister:
+	clk_unregister_composite(clk);
+err_free_mult:
+	kfree(mult);
+err_free_gate:
+	kfree(gate);
+err_unmap:
+	iounmap(reg);
+	of_address_to_resource(node, 0, &res);
+	release_mem_region(res.start, resource_size(&res));
+}
+
+CLK_OF_DECLARE(sun4i_a10_pll3, "allwinner,sun4i-a10-pll3-clk",
+	       sun4i_a10_pll3_setup);