[PATCHv10 05/41] CLK: TI: add autoidle support
Tero Kristo
t-kristo at ti.com
Tue Nov 26 03:05:46 EST 2013
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 at ti.com>
---
.../devicetree/bindings/clock/ti/autoidle.txt | 39 ++++++
arch/arm/mach-omap2/clock.c | 6 +
drivers/clk/ti/Makefile | 2 +-
drivers/clk/ti/autoidle.c | 134 ++++++++++++++++++++
include/linux/clk/ti.h | 9 ++
5 files changed, 189 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..7c735dd
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/autoidle.txt
@@ -0,0 +1,39 @@
+Binding for Texas Instruments autoidle clock.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1]. It assumes a register mapped
+clock which can be put to idle automatically by hardware based on the usage
+and a configuration bit setting. Autoidle clock is never an individual
+clock, it is always a derivative of some basic clock like a gate, divider,
+or fixed-factor.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- reg : offset for the register controlling the autoidle
+- ti,autoidle-shift : bit shift of the autoidle enable bit
+- ti,invert-autoidle-bit : autoidle is enabled by setting the bit to 0
+
+Examples:
+ dpll_core_m4_ck: dpll_core_m4_ck {
+ #clock-cells = <0>;
+ compatible = "ti,divider-clock";
+ clocks = <&dpll_core_x2_ck>;
+ ti,max-div = <31>;
+ ti,autoidle-shift = <8>;
+ reg = <0x2d38>;
+ ti,index-starts-at-one;
+ ti,invert-autoidle-bit;
+ };
+
+ dpll_usb_clkdcoldo_ck: dpll_usb_clkdcoldo_ck {
+ #clock-cells = <0>;
+ compatible = "ti,fixed-factor-clock";
+ clocks = <&dpll_usb_ck>;
+ ti,clock-div = <1>;
+ ti,autoidle-shift = <8>;
+ reg = <0x01b4>;
+ ti,clock-mult = <1>;
+ ti,invert-autoidle-bit;
+ };
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index c7c5d31..238be3f 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_ti_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_ti_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..01c9250
--- /dev/null
+++ b/drivers/clk/ti/autoidle.c
@@ -0,0 +1,134 @@
+/*
+ * TI clock autoidle support
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ *
+ * Tero Kristo <t-kristo at 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>
+#include <linux/clk/ti.h>
+
+struct clk_ti_autoidle {
+ void __iomem *reg;
+ struct regmap *regmap;
+ u8 shift;
+ u8 flags;
+ const char *name;
+ struct list_head node;
+};
+
+#define AUTOIDLE_LOW 0x1
+
+static LIST_HEAD(autoidle_clks);
+
+static void ti_allow_autoidle(struct clk_ti_autoidle *clk)
+{
+ u32 val;
+
+ val = clk_readl(clk->reg);
+
+ if (clk->flags & AUTOIDLE_LOW)
+ val &= ~(1 << clk->shift);
+ else
+ val |= (1 << clk->shift);
+
+ clk_writel(val, clk->reg);
+}
+
+static void ti_deny_autoidle(struct clk_ti_autoidle *clk)
+{
+ u32 val;
+
+ val = clk_readl(clk->reg);
+
+ if (clk->flags & AUTOIDLE_LOW)
+ val |= (1 << clk->shift);
+ else
+ val &= ~(1 << clk->shift);
+
+ clk_writel(val, clk->reg);
+}
+
+/**
+ * of_ti_clk_allow_autoidle_all - enable autoidle for all clocks
+ *
+ * Enables hardware autoidle for all registered DT clocks, which have
+ * the feature.
+ */
+void of_ti_clk_allow_autoidle_all(void)
+{
+ struct clk_ti_autoidle *c;
+
+ list_for_each_entry(c, &autoidle_clks, node)
+ ti_allow_autoidle(c);
+}
+
+/**
+ * of_ti_clk_deny_autoidle_all - disable autoidle for all clocks
+ *
+ * Disables hardware autoidle for all registered DT clocks, which have
+ * the feature.
+ */
+void of_ti_clk_deny_autoidle_all(void)
+{
+ struct clk_ti_autoidle *c;
+
+ list_for_each_entry(c, &autoidle_clks, node)
+ ti_deny_autoidle(c);
+}
+
+/**
+ * of_ti_clk_autoidle_setup - sets up hardware autoidle for a clock
+ * @node: pointer to the clock device node
+ *
+ * Checks if a clock has hardware autoidle support or not (check
+ * for presence of 'ti,autoidle-shift' property in the device tree
+ * node) and sets up the hardware autoidle feature for the clock
+ * if available. If autoidle is available, the clock is also added
+ * to the autoidle list for later processing. Returns 0 on success,
+ * negative error value on failure.
+ */
+int __init of_ti_clk_autoidle_setup(struct device_node *node)
+{
+ u32 shift;
+ struct clk_ti_autoidle *clk;
+
+ /* Check if this clock has autoidle support or not */
+ if (of_property_read_u32(node, "ti,autoidle-shift", &shift))
+ return 0;
+
+ clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+
+ if (!clk)
+ return -ENOMEM;
+
+ clk->shift = shift;
+ clk->name = node->name;
+ clk->reg = ti_clk_get_reg_addr(node, 0);
+
+ if (!clk->reg) {
+ kfree(clk);
+ return -EINVAL;
+ }
+
+ if (of_property_read_bool(node, "ti,invert-autoidle-bit"))
+ clk->flags |= AUTOIDLE_LOW;
+
+ list_add(&clk->node, &autoidle_clks);
+
+ return 0;
+}
diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
index fe32294..58a3c7e 100644
--- a/include/linux/clk/ti.h
+++ b/include/linux/clk/ti.h
@@ -219,6 +219,15 @@ int omap3_dpll4_set_rate(struct clk_hw *clk, unsigned long rate,
void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index);
void ti_dt_clocks_register(struct ti_dt_clk *oclks);
void ti_dt_clk_init_provider(struct device_node *np, int index);
+int of_ti_clk_autoidle_setup(struct device_node *node);
+
+#ifdef CONFIG_OF
+void of_ti_clk_allow_autoidle_all(void);
+void of_ti_clk_deny_autoidle_all(void);
+#else
+static inline void of_ti_clk_allow_autoidle_all(void) { }
+static inline void of_ti_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
More information about the linux-arm-kernel
mailing list