[PATCH v3 02/19] clk: sunxi: Add display and TCON0 clocks driver

Maxime Ripard
2016-03-23T16:38:51Z

The A10 SoCs and its relatives has a special clock controller to drive the
display engines (both frontend and backend), that have a lot in common with
the clock to drive the first TCON channel.

Add a driver to support both.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
Documentation/devicetree/bindings/clock/sunxi.txt | 2 +
drivers/clk/sunxi/Makefile | 1 +
drivers/clk/sunxi/clk-sun4i-display.c | 262 ++++++++++++++++++++++
3 files changed, 265 insertions(+)
create mode 100644 drivers/clk/sunxi/clk-sun4i-display.c

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index 834436fbe83d..50e212bc8923 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -64,6 +64,7 @@ Required properties:
"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,sun4i-a10-display-clk" - for the display clocks on the A10
"allwinner,sun5i-a13-mbus-clk" - for the MBUS clock on A13
"allwinner,sun4i-a10-mmc-clk" - for the MMC clock
"allwinner,sun9i-a80-mmc-clk" - for mmc module clocks on A80
@@ -73,6 +74,7 @@ Required properties:
"allwinner,sun8i-a23-mbus-clk" - for the MBUS clock on A23
"allwinner,sun7i-a20-out-clk" - for the external output clocks
"allwinner,sun7i-a20-gmac-clk" - for the GMAC clock module on A20/A31
+ "allwinner,sun4i-a10-tcon-ch0-clk" - for the TCON channel 0 clock on the A10
"allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
"allwinner,sun5i-a13-usb-clk" - for usb gates + resets on A13
"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index 3fd7901d48e4..37a6a642a037 100644
--- a/drivers/clk/sunxi/Makefile
+++ b/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-display.o
obj-y += clk-sun8i-bus-gates.o
obj-y += clk-sun8i-mbus.o
obj-y += clk-sun9i-core.o
diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
new file mode 100644
index 000000000000..af7d1faebdec
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sun4i-display.c
@@ -0,0 +1,262 @@
+/*
+ * 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/kernel.h>
+#include <linux/of_address.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+struct sun4i_a10_display_clk_data {
+ bool has_div;
+ u8 has_rst;
+ u8 parents;
+
+ u8 offset_en;
+ u8 offset_div;
+ u8 offset_mux;
+ u8 offset_rst;
+
+ u8 width_div;
+ u8 width_mux;
+};
+
+struct reset_data {
+ void __iomem *reg;
+ spinlock_t *lock;
+ struct reset_controller_dev rcdev;
+ u8 offset;
+};
+
+static DEFINE_SPINLOCK(sun4i_a10_display_lock);
+
+static inline struct reset_data *rcdev_to_reset_data(struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct reset_data, rcdev);
+};
+
+static int sun4i_a10_display_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct reset_data *data = rcdev_to_reset_data(rcdev);
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(data->lock, flags);
+
+ reg = readl(data->reg);
+ writel(reg & ~BIT(data->offset + id), data->reg);
+
+ spin_unlock_irqrestore(data->lock, flags);
+
+ return 0;
+}
+
+static int sun4i_a10_display_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct reset_data *data = rcdev_to_reset_data(rcdev);
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(data->lock, flags);
+
+ reg = readl(data->reg);
+ writel(reg | BIT(data->offset + id), data->reg);
+
+ spin_unlock_irqrestore(data->lock, flags);
+
+ return 0;
+}
+
+static int sun4i_a10_display_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct reset_data *data = rcdev_to_reset_data(rcdev);
+
+ return !(readl(data->reg) & BIT(data->offset + id));
+}
+
+static const struct reset_control_ops sun4i_a10_display_reset_ops = {
+ .assert = sun4i_a10_display_assert,
+ .deassert = sun4i_a10_display_deassert,
+ .status = sun4i_a10_display_status,
+};
+
+static int sun4i_a10_display_reset_xlate(struct reset_controller_dev *rcdev,
+ const struct of_phandle_args *spec)
+{
+ /* We only have a single reset signal */
+ return 0;
+}
+
+static void __init sun4i_a10_display_init(struct device_node *node,
+ struct sun4i_a10_display_clk_data *data)
+{
+ const char *parents[data->parents];
+ const char *clk_name = node->name;
+ struct reset_data *reset_data;
+ struct clk_divider *div = NULL;
+ struct clk_gate *gate;
+ struct resource res;
+ struct clk_mux *mux;
+ void __iomem *reg;
+ struct clk *clk;
+ int ret;
+
+ 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;
+ }
+
+ ret = of_clk_parent_fill(node, parents, data->parents);
+ if (ret != data->parents) {
+ pr_err("%s Could not retrieve the parents\n", clk_name);
+ goto unmap;
+ }
+
+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ goto unmap;
+
+ mux->reg = reg;
+ mux->shift = data->offset_mux;
+ mux->mask = (1 << data->width_mux) - 1;
+ mux->lock = &sun4i_a10_display_lock;
+
+ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+ if (!gate)
+ goto free_mux;
+
+ gate->reg = reg;
+ gate->bit_idx = data->offset_en;
+ gate->lock = &sun4i_a10_display_lock;
+
+ if (data->has_div) {
+ div = kzalloc(sizeof(*div), GFP_KERNEL);
+ if (!div)
+ goto free_gate;
+
+ div->reg = reg;
+ div->shift = data->offset_div;
+ div->width = data->width_div;
+ div->lock = &sun4i_a10_display_lock;
+ }
+
+ clk = clk_register_composite(NULL, clk_name,
+ parents, data->parents,
+ &mux->hw, &clk_mux_ops,
+ data->has_div ? &div->hw : NULL,
+ data->has_div ? &clk_divider_ops : NULL,
+ &gate->hw, &clk_gate_ops,
+ 0);
+ if (IS_ERR(clk)) {
+ pr_err("%s: Couldn't register the clock\n", clk_name);
+ goto free_div;
+ }
+
+ 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 free_clk;
+ }
+
+ if (!data->has_rst)
+ return;
+
+ reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
+ if (!reset_data)
+ goto free_of_clk;
+
+ reset_data->reg = reg;
+ reset_data->offset = data->offset_rst;
+ reset_data->lock = &sun4i_a10_display_lock;
+ reset_data->rcdev.nr_resets = data->has_rst;
+ reset_data->rcdev.ops = &sun4i_a10_display_reset_ops;
+ reset_data->rcdev.of_node = node;
+
+ if (data->has_rst == 1) {
+ reset_data->rcdev.of_reset_n_cells = 0;
+ reset_data->rcdev.of_xlate = &sun4i_a10_display_reset_xlate;
+ } else {
+ reset_data->rcdev.of_reset_n_cells = 1;
+ }
+
+ 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_of_clk:
+ of_clk_del_provider(node);
+free_clk:
+ clk_unregister_composite(clk);
+free_div:
+ if (data->has_div)
+ kfree(div);
+free_gate:
+ kfree(gate);
+free_mux:
+ kfree(mux);
+unmap:
+ iounmap(reg);
+ of_address_to_resource(node, 0, &res);
+ release_mem_region(res.start, resource_size(&res));
+}
+
+static struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data = {
+ .has_rst = 2,
+ .parents = 4,
+ .offset_en = 31,
+ .offset_rst = 29,
+ .offset_mux = 24,
+ .width_mux = 2,
+};
+
+static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
+{
+ sun4i_a10_display_init(node, &sun4i_a10_tcon_ch0_data);
+}
+CLK_OF_DECLARE(sun4i_a10_tcon_ch0, "allwinner,sun4i-a10-tcon-ch0-clk",
+ sun4i_a10_tcon_ch0_setup);
+
+static struct sun4i_a10_display_clk_data sun4i_a10_display_data = {
+ .has_div = true,
+ .has_rst = 1,
+ .parents = 3,
+ .offset_en = 31,
+ .offset_rst = 30,
+ .offset_mux = 24,
+ .offset_div = 0,
+ .width_mux = 2,
+ .width_div = 4,
+};
+
+static void __init sun4i_a10_display_setup(struct device_node *node)
+{
+ sun4i_a10_display_init(node, &sun4i_a10_display_data);
+}
+CLK_OF_DECLARE(sun4i_a10_display, "allwinner,sun4i-a10-display-clk",
+ sun4i_a10_display_setup);
--
2.7.3