[PATCHv6 03/45] CLK: TI: add autoidle support

[Tero Kristo <t-kristo@ti.com>]

TI clk driver now routes some of the basic clocks through own
registration routine to allow autoidle support. This routine just
checks a couple of device node properties and adds autoidle support
if required, and just passes the registration forward to basic clocks.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
---
 .../devicetree/bindings/clock/ti/autoidle.txt      |   48 ++++++++
 arch/arm/mach-omap2/clock.c                        |    6 +
 drivers/clk/ti/Makefile                            |    2 +-
 drivers/clk/ti/autoidle.c                          |  121 ++++++++++++++++++++
 include/linux/clk/ti.h                             |    7 ++
 5 files changed, 183 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/clock/ti/autoidle.txt
 create mode 100644 drivers/clk/ti/autoidle.c

diff --git a/Documentation/devicetree/bindings/clock/ti/autoidle.txt b/Documentation/devicetree/bindings/clock/ti/autoidle.txt
new file mode 100644
index 0000000..cc09910
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/autoidle.txt
@@ -0,0 +1,48 @@
+Binding for Texas Instruments autoidling clock.
+
+This binding uses the common clock binding[1]. Autoidle clocks
+are inherited clocks from basic divider-clock [2] or
+fixed-factor-clock [3] and just add autoidle support on top of
+this. Autoidle is an OMAP clock feature, which allows the clock
+to gate autonomously by hardware when they are no longer needed.
+The autoidle feature must be enabled manually for these clocks.
+Otherwise the clocks behave exactly as their base clock type.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Documentation/devicetree/bindings/clock/divider-clock.txt
+[3] Documentation/devicetree/bindings/clock/fixed-factor-clock.txt
+
+Required properties:
+- compatible : shall be one of:
+		"ti,divider-clock",
+		"ti,fixed-factor-clock"
+- ti,autoidle-shift : bit shift of the autoidle enable bit for the clock
+- reg : base address for the control register of this clock
+
+Optional properties:
+- ti,autoidle-low : autoidle is enabled by setting the bit to 0
+
+Other properties as per the base clock type.
+
+Examples:
+	dpll_abe_m2x2_ck: dpll_abe_m2x2_ck@4a0051f0 {
+		#clock-cells = <0>;
+		compatible = "ti,divider-clock";
+		clocks = <&dpll_abe_x2_ck>;
+		ti,autoidle-shift = <8>;
+		reg = <0x4a0051f0 0x4>;
+		bit-mask = <0x1f>;
+		index-starts-at-one;
+		ti,autoidle-low;
+	};
+
+	dpll_usb_clkdcoldo_ck: dpll_usb_clkdcoldo_ck@4a0081b4 {
+		#clock-cells = <0>;
+		compatible = "ti,fixed-factor-clock";
+		clocks = <&dpll_usb_ck>;
+		ti,autoidle-shift = <8>;
+		clock-div = <1>;
+		reg = <0x4a0081b4 0x4>;
+		clock-mult = <1>;
+		ti,autoidle-low;
+	};
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index 0c38ca9..669d4c4 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -520,6 +520,9 @@ int omap2_clk_enable_autoidle_all(void)
 	list_for_each_entry(c, &clk_hw_omap_clocks, node)
 		if (c->ops && c->ops->allow_idle)
 			c->ops->allow_idle(c);
+
+	of_omap_clk_allow_autoidle_all();
+
 	return 0;
 }
 
@@ -539,6 +542,9 @@ int omap2_clk_disable_autoidle_all(void)
 	list_for_each_entry(c, &clk_hw_omap_clocks, node)
 		if (c->ops && c->ops->deny_idle)
 			c->ops->deny_idle(c);
+
+	of_omap_clk_deny_autoidle_all();
+
 	return 0;
 }
 
diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile
index 05af5d8..533efb4 100644
--- a/drivers/clk/ti/Makefile
+++ b/drivers/clk/ti/Makefile
@@ -1,3 +1,3 @@
 ifneq ($(CONFIG_OF),)
-obj-y					+= clk.o dpll.o
+obj-y					+= clk.o dpll.o autoidle.o
 endif
diff --git a/drivers/clk/ti/autoidle.c b/drivers/clk/ti/autoidle.c
new file mode 100644
index 0000000..a52a42b
--- /dev/null
+++ b/drivers/clk/ti/autoidle.c
@@ -0,0 +1,121 @@
+/*
+ * OMAP clock autoidle support
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; 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/slab.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+struct clk_omap_autoidle {
+	void __iomem		*reg;
+	u8			shift;
+	u8			flags;
+	const char		*name;
+	struct list_head	node;
+};
+
+#define AUTOIDLE_LOW		0x1
+
+static LIST_HEAD(autoidle_clks);
+
+static void omap_allow_autoidle(struct clk_omap_autoidle *clk)
+{
+	u32 val;
+
+	val = readl(clk->reg);
+
+	if (clk->flags & AUTOIDLE_LOW)
+		val &= ~(1 << clk->shift);
+	else
+		val |= (1 << clk->shift);
+
+	writel(val, clk->reg);
+}
+
+static void omap_deny_autoidle(struct clk_omap_autoidle *clk)
+{
+	u32 val;
+
+	val = readl(clk->reg);
+
+	if (clk->flags & AUTOIDLE_LOW)
+		val |= (1 << clk->shift);
+	else
+		val &= ~(1 << clk->shift);
+
+	writel(val, clk->reg);
+}
+
+void of_omap_clk_allow_autoidle_all(void)
+{
+	struct clk_omap_autoidle *c;
+
+	list_for_each_entry(c, &autoidle_clks, node)
+		omap_allow_autoidle(c);
+}
+
+void of_omap_clk_deny_autoidle_all(void)
+{
+	struct clk_omap_autoidle *c;
+
+	list_for_each_entry(c, &autoidle_clks, node)
+		omap_deny_autoidle(c);
+}
+
+static void __init of_omap_autoidle_setup(struct device_node *node)
+{
+	u32 shift;
+	void __iomem *reg;
+	struct clk_omap_autoidle *clk;
+
+	if (of_property_read_u32(node, "ti,autoidle-shift", &shift))
+		return;
+
+	reg = of_iomap(node, 0);
+
+	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+
+	if (!clk) {
+		pr_err("%s: kzalloc failed\n", __func__);
+		return;
+	}
+
+	clk->shift = shift;
+	clk->name = node->name;
+	clk->reg = reg;
+
+	if (of_property_read_bool(node, "ti,autoidle-low"))
+		clk->flags |= AUTOIDLE_LOW;
+
+	list_add(&clk->node, &autoidle_clks);
+}
+
+static void __init of_omap_divider_setup(struct device_node *node)
+{
+	of_divider_clk_setup(node);
+	of_omap_autoidle_setup(node);
+}
+CLK_OF_DECLARE(omap_divider_clock, "ti,divider-clock", of_omap_divider_setup);
+
+static void __init of_omap_fixed_factor_setup(struct device_node *node)
+{
+	of_fixed_factor_clk_setup(node);
+	of_omap_autoidle_setup(node);
+}
+CLK_OF_DECLARE(omap_fixed_factor_clock, "ti,fixed-factor-clock",
+	       of_omap_fixed_factor_setup);
diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
index 1c4f492..e2473b8 100644
--- a/include/linux/clk/ti.h
+++ b/include/linux/clk/ti.h
@@ -180,6 +180,13 @@ int omap3_dpll4_set_rate(struct clk_hw *clk, unsigned long rate,
 			 unsigned long parent_rate);
 
 void omap_dt_clocks_register(struct omap_dt_clk *oclks);
+#ifdef CONFIG_OF
+void of_omap_clk_allow_autoidle_all(void);
+void of_omap_clk_deny_autoidle_all(void);
+#else
+static inline void of_omap_clk_allow_autoidle_all(void) { }
+static inline void of_omap_clk_deny_autoidle_all(void) { }
+#endif
 
 extern const struct clk_hw_omap_ops clkhwops_omap3_dpll;
 extern const struct clk_hw_omap_ops clkhwops_omap4_dpllmx;
-- 
1.7.9.5