[PATCH 03/19] clk: sunxi: Add TCON channel0 clock

[Maxime Ripard]

The TCON is a controller generating the timings to output videos signals,
acting like both a CRTC and an encoder.

It has two channels depending on the output, each channel being driven by
its own clock (and own clock controller).

Add a driver for the channel 0 clock.

Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
---
 drivers/clk/sunxi/Makefile             |   1 +
 drivers/clk/sunxi/clk-sun4i-tcon-ch0.c | 173 +++++++++++++++++++++++++++++++++
 2 files changed, 174 insertions(+)
 create mode 100644 drivers/clk/sunxi/clk-sun4i-tcon-ch0.c

diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index 40c32ffd912c..7821b2b63d58 100644
--- a/drivers/clk/sunxi/Makefile
+++ b/drivers/clk/sunxi/Makefile
@@ -12,6 +12,7 @@ obj-y += clk-mod0.o
 obj-y += clk-simple-gates.o
 obj-y += clk-sun4i-display.o
 obj-y += clk-sun4i-pll3.o
+obj-y += clk-sun4i-tcon-ch0.o
 obj-y += clk-sun8i-mbus.o
 obj-y += clk-sun9i-core.o
 obj-y += clk-sun9i-mmc.o
diff --git a/drivers/clk/sunxi/clk-sun4i-tcon-ch0.c b/drivers/clk/sunxi/clk-sun4i-tcon-ch0.c
new file mode 100644
index 000000000000..db10cfb94a1d
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sun4i-tcon-ch0.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright 2015 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard at 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_address.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define SUN4I_A10_TCON_CH0_PARENTS	4
+
+#define SUN4I_A10_TCON_CH0_GATE_BIT	31
+#define SUN4I_A10_TCON_CH0_RESET_SHIFT	29
+#define SUN4I_A10_TCON_CH0_MUX_MASK	3
+#define SUN4I_A10_TCON_CH0_MUX_SHIFT	24
+
+struct reset_data {
+	void __iomem			*reg;
+	spinlock_t			*lock;
+	struct reset_controller_dev	rcdev;
+};
+
+static DEFINE_SPINLOCK(sun4i_a10_tcon_ch0_lock);
+
+static int sun4i_a10_tcon_ch0_assert(struct reset_controller_dev *rcdev,
+				     unsigned long id)
+{
+	struct reset_data *data = container_of(rcdev,
+					       struct reset_data,
+					       rcdev);
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(data->lock, flags);
+
+	reg = readl(data->reg);
+	writel(reg & ~BIT(SUN4I_A10_TCON_CH0_RESET_SHIFT + id), data->reg);
+
+	spin_unlock_irqrestore(data->lock, flags);
+
+	return 0;
+}
+
+static int sun4i_a10_tcon_ch0_deassert(struct reset_controller_dev *rcdev,
+				       unsigned long id)
+{
+	struct reset_data *data = container_of(rcdev,
+						   struct reset_data,
+						   rcdev);
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(data->lock, flags);
+
+	reg = readl(data->reg);
+	writel(reg | BIT(SUN4I_A10_TCON_CH0_RESET_SHIFT + id), data->reg);
+
+	spin_unlock_irqrestore(data->lock, flags);
+
+	return 0;
+}
+
+static int sun4i_a10_tcon_ch0_status(struct reset_controller_dev *rcdev,
+				     unsigned long id)
+{
+	struct reset_data *data = container_of(rcdev,
+					       struct reset_data,
+					       rcdev);
+
+	return !(readl(data->reg) & BIT(SUN4I_A10_TCON_CH0_RESET_SHIFT + id));
+}
+
+static struct reset_control_ops sun4i_a10_tcon_ch0_reset_ops = {
+	.assert		= sun4i_a10_tcon_ch0_assert,
+	.deassert	= sun4i_a10_tcon_ch0_deassert,
+	.status		= sun4i_a10_tcon_ch0_status,
+};
+
+static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
+{
+	const char *parents[SUN4I_A10_TCON_CH0_PARENTS];
+	const char *clk_name = node->name;
+	struct reset_data *reset_data;
+	struct clk_gate *gate;
+	struct clk_mux *mux;
+	void __iomem *reg;
+	struct clk *clk;
+	int i;
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	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;
+	}
+
+	for (i = 0; i < SUN4I_A10_TCON_CH0_PARENTS; i++)
+		parents[i] = of_clk_get_parent_name(node, i);
+
+	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return;
+
+	mux->reg = reg;
+	mux->shift = SUN4I_A10_TCON_CH0_MUX_SHIFT;
+	mux->mask = SUN4I_A10_TCON_CH0_MUX_MASK;
+	mux->lock = &sun4i_a10_tcon_ch0_lock;
+
+	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		goto free_mux;
+
+	gate->reg = reg;
+	gate->bit_idx = SUN4I_A10_TCON_CH0_GATE_BIT;
+	gate->lock = &sun4i_a10_tcon_ch0_lock;
+
+	clk = clk_register_composite(NULL, clk_name,
+				     parents, SUN4I_A10_TCON_CH0_PARENTS,
+				     &mux->hw, &clk_mux_ops,
+				     NULL, NULL,
+				     &gate->hw, &clk_gate_ops,
+				     0);
+	if (IS_ERR(clk)) {
+		pr_err("%s: Couldn't register the clock\n", clk_name);
+		goto free_gate;
+	}
+
+	of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+	reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
+	if (!reset_data)
+		goto free_clk;
+
+	reset_data->reg = reg;
+	reset_data->lock = &sun4i_a10_tcon_ch0_lock;
+	reset_data->rcdev.nr_resets = 2;
+	reset_data->rcdev.ops = &sun4i_a10_tcon_ch0_reset_ops;
+	reset_data->rcdev.of_node = node;
+
+	if (reset_controller_register(&reset_data->rcdev)) {
+		pr_err("%s: Couldn't register the reset controller\n",
+		       clk_name);
+		goto free_reset;
+	}
+
+	return;
+
+free_reset:
+	kfree(reset_data);
+free_clk:
+	clk_unregister(clk);
+free_gate:
+	kfree(gate);
+free_mux:
+	kfree(mux);
+}
+
+CLK_OF_DECLARE(sun4i_a10_tcon_ch0, "allwinner,sun4i-a10-tcon-ch0-clk",
+	       sun4i_a10_tcon_ch0_setup);
-- 
2.6.2