clk: sunxi: Add display and TCON0 clocks driver

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>
[sboyd@codeaurora.org: Silence variable sized array warning]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

3 files changed, 264 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index f70f500256bb..8f7619d8c8d8 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -64,6 +64,7 @@ Required properties:
         "allwinner,sun8i-a83t-bus-gates-clk" - for the bus gates on A83T
         "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-display-clk" - for the display clocks on the A10
         "allwinner,sun4i-a10-dram-gates-clk" - for the DRAM gates on A10
         "allwinner,sun5i-a13-dram-gates-clk" - for the DRAM gates on A13
         "allwinner,sun5i-a13-mbus-clk" - for the MBUS clock on A13
@@ -75,6 +76,7 @@ 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-tcon-ch1-clk" - for the TCON channel 1 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
diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index 2d77407a0037..39d2044a1f49 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-sun4i-pll3.o
 obj-y += clk-sun4i-tcon-ch1.o
 obj-y += clk-sun8i-bus-gates.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..445a7498d6df
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sun4i-display.c
@@ -0,0 +1,261 @@
+/*
+ * 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      num_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,
+                                          const struct sun4i_a10_display_clk_data *data)
+{
+        const char *parents[4];
+        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->num_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->num_rst;
+        reset_data->rcdev.ops = &sun4i_a10_display_reset_ops;
+        reset_data->rcdev.of_node = node;
+
+        if (data->num_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:
+        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 const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initconst = {
+        .num_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 const struct sun4i_a10_display_clk_data sun4i_a10_display_data __initconst = {
+        .has_div        = true,
+        .num_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);