[PATCH v3 04/19] clk: sunxi: Add TCON channel1 clock

Maxime Ripard
2016-03-23T16:39:54Z

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 1 clock.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
Documentation/devicetree/bindings/clock/sunxi.txt | 1 +
drivers/clk/sunxi/Makefile | 1 +
drivers/clk/sunxi/clk-sun4i-tcon-ch1.c | 300 ++++++++++++++++++++++
3 files changed, 302 insertions(+)
create mode 100644 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index 0e1e2c0eee61..54192c1a98dc 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -76,6 +76,7 @@ Required properties:
"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
"allwinner,sun6i-a31-usb-clk" - for usb gates + resets on A31
diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index 244defcfa5db..39d2044a1f49 100644
--- a/drivers/clk/sunxi/Makefile
+++ b/drivers/clk/sunxi/Makefile
@@ -13,6 +13,7 @@ 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-ch1.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-tcon-ch1.c b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
new file mode 100644
index 000000000000..98a4582de56a
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
@@ -0,0 +1,300 @@
+/*
+ * 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 TCON_CH1_SCLK2_PARENTS 4
+
+#define TCON_CH1_SCLK2_GATE_BIT BIT(31)
+#define TCON_CH1_SCLK2_MUX_MASK 3
+#define TCON_CH1_SCLK2_MUX_SHIFT 24
+#define TCON_CH1_SCLK2_DIV_MASK 0xf
+#define TCON_CH1_SCLK2_DIV_SHIFT 0
+
+#define TCON_CH1_SCLK1_GATE_BIT BIT(15)
+#define TCON_CH1_SCLK1_HALF_BIT BIT(11)
+
+struct tcon_ch1_clk {
+ struct clk_hw hw;
+ spinlock_t lock;
+ void __iomem *reg;
+};
+
+#define hw_to_tclk(hw) container_of(hw, struct tcon_ch1_clk, hw)
+
+static void tcon_ch1_disable(struct clk_hw *hw)
+{
+ struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&tclk->lock, flags);
+ reg = readl(tclk->reg);
+ reg &= ~(TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT);
+ writel(reg, tclk->reg);
+ spin_unlock_irqrestore(&tclk->lock, flags);
+}
+
+static int tcon_ch1_enable(struct clk_hw *hw)
+{
+ struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&tclk->lock, flags);
+ reg = readl(tclk->reg);
+ reg |= TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT;
+ writel(reg, tclk->reg);
+ spin_unlock_irqrestore(&tclk->lock, flags);
+
+ return 0;
+}
+
+static int tcon_ch1_is_enabled(struct clk_hw *hw)
+{
+ struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
+ u32 reg;
+
+ reg = readl(tclk->reg);
+ return reg & (TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT);
+}
+
+static u8 tcon_ch1_get_parent(struct clk_hw *hw)
+{
+ struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
+ int num_parents = clk_hw_get_num_parents(hw);
+ u32 reg;
+
+ reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT;
+ reg &= reg >> TCON_CH1_SCLK2_MUX_MASK;
+
+ if (reg >= num_parents)
+ return -EINVAL;
+
+ return reg;
+}
+
+static int tcon_ch1_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&tclk->lock, flags);
+ reg = readl(tclk->reg);
+ reg &= ~(TCON_CH1_SCLK2_MUX_MASK << TCON_CH1_SCLK2_MUX_SHIFT);
+ reg |= index << TCON_CH1_SCLK2_MUX_SHIFT;
+ writel(reg, tclk->reg);
+ spin_unlock_irqrestore(&tclk->lock, flags);
+
+ return 0;
+};
+
+static unsigned long tcon_ch1_calc_divider(unsigned long rate,
+ unsigned long parent_rate,
+ u8 *div,
+ bool *half)
+{
+ unsigned long best_rate = 0;
+ u8 best_m = 0, m;
+ bool is_double;
+
+ for (m = 1; m < 16; m++) {
+ u8 d;
+
+ for (d = 1; d < 3; d++) {
+ unsigned long tmp_rate;
+
+ tmp_rate = parent_rate / m / d;
+
+ if (tmp_rate > rate)
+ continue;
+
+ if (!best_rate ||
+ (rate - tmp_rate) < (rate - best_rate)) {
+ best_rate = tmp_rate;
+ best_m = m;
+ is_double = d;
+ }
+ }
+ }
+
+ if (div && half) {
+ *div = best_m;
+ *half = is_double;
+ }
+
+ return best_rate;
+}
+
+static int tcon_ch1_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ long best_rate = -EINVAL;
+ int i;
+
+ for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+ unsigned long parent_rate;
+ unsigned long tmp_rate;
+ struct clk_hw *parent;
+
+ parent = clk_hw_get_parent_by_index(hw, i);
+ if (!parent)
+ continue;
+
+ parent_rate = clk_hw_get_rate(parent);
+
+ tmp_rate = tcon_ch1_calc_divider(req->rate, parent_rate,
+ NULL, NULL);
+
+ if (best_rate < 0 ||
+ (req->rate - tmp_rate) < (req->rate - best_rate)) {
+ best_rate = tmp_rate;
+ req->best_parent_rate = parent_rate;
+ req->best_parent_hw = parent;
+ }
+ }
+
+ if (best_rate < 0)
+ return best_rate;
+
+ req->rate = best_rate;
+ return 0;
+}
+
+static unsigned long tcon_ch1_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
+ u32 reg;
+
+ reg = readl(tclk->reg);
+
+ parent_rate /= (reg & TCON_CH1_SCLK2_DIV_MASK) + 1;
+
+ if (reg & TCON_CH1_SCLK1_HALF_BIT)
+ parent_rate /= 2;
+
+ return parent_rate;
+}
+
+static int tcon_ch1_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct tcon_ch1_clk *tclk = hw_to_tclk(hw);
+ unsigned long flags;
+ bool half;
+ u8 div_m;
+ u32 reg;
+
+ tcon_ch1_calc_divider(rate, parent_rate, &div_m, &half);
+
+ spin_lock_irqsave(&tclk->lock, flags);
+ reg = readl(tclk->reg);
+ reg &= ~(TCON_CH1_SCLK2_DIV_MASK | TCON_CH1_SCLK1_HALF_BIT);
+ reg |= (div_m - 1) & TCON_CH1_SCLK2_DIV_MASK;
+
+ if (half)
+ reg |= TCON_CH1_SCLK1_HALF_BIT;
+
+ writel(reg, tclk->reg);
+ spin_unlock_irqrestore(&tclk->lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops tcon_ch1_ops = {
+ .disable = tcon_ch1_disable,
+ .enable = tcon_ch1_enable,
+ .is_enabled = tcon_ch1_is_enabled,
+
+ .get_parent = tcon_ch1_get_parent,
+ .set_parent = tcon_ch1_set_parent,
+
+ .determine_rate = tcon_ch1_determine_rate,
+ .recalc_rate = tcon_ch1_recalc_rate,
+ .set_rate = tcon_ch1_set_rate,
+};
+
+static void __init tcon_ch1_setup(struct device_node *node)
+{
+ const char *parents[TCON_CH1_SCLK2_PARENTS];
+ const char *clk_name = node->name;
+ struct clk_init_data init;
+ struct tcon_ch1_clk *tclk;
+ struct resource res;
+ struct clk *clk;
+ void __iomem *reg;
+ 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, TCON_CH1_SCLK2_PARENTS);
+ if (ret != TCON_CH1_SCLK2_PARENTS) {
+ pr_err("%s Could not retrieve the parents\n", clk_name);
+ goto err_unmap;
+ }
+
+ tclk = kzalloc(sizeof(*tclk), GFP_KERNEL);
+ if (!tclk)
+ goto err_unmap;
+
+ init.name = clk_name;
+ init.ops = &tcon_ch1_ops;
+ init.parent_names = parents;
+ init.num_parents = TCON_CH1_SCLK2_PARENTS;
+ init.flags = CLK_SET_RATE_PARENT;
+
+ tclk->reg = reg;
+ tclk->hw.init = &init;
+ spin_lock_init(&tclk->lock);
+
+ clk = clk_register(NULL, &tclk->hw);
+ if (IS_ERR(clk)) {
+ pr_err("%s: Couldn't register the clock\n", clk_name);
+ goto err_free_data;
+ }
+
+ ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ if (ret) {
+ pr_err("%s: Couldn't register our clock provider\n", clk_name);
+ goto err_unregister_clk;
+ }
+
+ return;
+
+err_unregister_clk:
+ clk_unregister(clk);
+err_free_data:
+ kfree(tclk);
+err_unmap:
+ iounmap(reg);
+ of_address_to_resource(node, 0, &res);
+ release_mem_region(res.start, resource_size(&res));
+}
+
+CLK_OF_DECLARE(tcon_ch1, "allwinner,sun4i-a10-tcon-ch1-clk",
+ tcon_ch1_setup);
--
2.7.3