[PATCHv9 08/43] clk: ti: add composite clock support
Tero Kristo
t-kristo at ti.com
Fri Oct 25 11:57:02 EDT 2013
This is a multipurpose clock node, which contains support for multiple
sub-clocks. Uses basic composite clock type to implement the actual
functionality, and TI specific gate, mux and divider clocks.
Signed-off-by: Tero Kristo <t-kristo at ti.com>
---
.../devicetree/bindings/clock/ti/composite.txt | 54 +++++
drivers/clk/ti/Makefile | 2 +-
drivers/clk/ti/composite.c | 222 ++++++++++++++++++++
include/linux/clk/ti.h | 8 +
4 files changed, 285 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/clock/ti/composite.txt
create mode 100644 drivers/clk/ti/composite.c
diff --git a/Documentation/devicetree/bindings/clock/ti/composite.txt b/Documentation/devicetree/bindings/clock/ti/composite.txt
new file mode 100644
index 0000000..5f43c47
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/composite.txt
@@ -0,0 +1,54 @@
+Binding for TI composite 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 composite clock with multiple different sub-types;
+
+a multiplexer clock with multiple input clock signals or parents, one
+of which can be selected as output, this behaves exactly as [2]
+
+an adjustable clock rate divider, this behaves exactly as [3]
+
+a gating function which can be used to enable and disable the output
+clock, this behaves exactly as [4]
+
+The binding must provide a list of the component clocks that shall be
+merged to this clock. The component clocks shall be of one of the
+"ti,*composite*-clock" types.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Documentation/devicetree/bindings/clock/ti/mux.txt
+[3] Documentation/devicetree/bindings/clock/ti/divider.txt
+[4] Documentation/devicetree/bindings/clock/ti/gate.txt
+
+Required properties:
+- compatible : shall be: "ti,composite-clock"
+- clocks : link phandles of component clocks
+- #clock-cells : from common clock binding; shall be set to 0.
+
+Examples:
+
+usb_l4_gate_ick: usb_l4_gate_ick {
+ #clock-cells = <0>;
+ compatible = "ti,composite-interface-clock";
+ clocks = <&l4_ick>;
+ ti,bit-shift = <5>;
+ reg = <0x0a10>;
+};
+
+usb_l4_div_ick: usb_l4_div_ick {
+ #clock-cells = <0>;
+ compatible = "ti,composite-divider-clock";
+ clocks = <&l4_ick>;
+ ti,bit-shift = <4>;
+ ti,max-div = <1>;
+ reg = <0x0a40>;
+ ti,index-starts-at-one;
+};
+
+usb_l4_ick: usb_l4_ick {
+ #clock-cells = <0>;
+ compatible = "ti,composite-clock";
+ clocks = <&usb_l4_gate_ick>, <&usb_l4_div_ick>;
+};
diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile
index 533efb4..a4a7595 100644
--- a/drivers/clk/ti/Makefile
+++ b/drivers/clk/ti/Makefile
@@ -1,3 +1,3 @@
ifneq ($(CONFIG_OF),)
-obj-y += clk.o dpll.o autoidle.o
+obj-y += clk.o dpll.o autoidle.o composite.o
endif
diff --git a/drivers/clk/ti/composite.c b/drivers/clk/ti/composite.c
new file mode 100644
index 0000000..9ce7e54
--- /dev/null
+++ b/drivers/clk/ti/composite.c
@@ -0,0 +1,222 @@
+/*
+ * TI composite clock 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>
+#include <linux/list.h>
+
+#define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
+
+static unsigned long ti_composite_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return clk_divider_ops.recalc_rate(hw, parent_rate);
+}
+
+static long ti_composite_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ return -EINVAL;
+}
+
+static int ti_composite_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ return -EINVAL;
+}
+
+static const struct clk_ops ti_composite_divider_ops = {
+ .recalc_rate = &ti_composite_recalc_rate,
+ .round_rate = &ti_composite_round_rate,
+ .set_rate = &ti_composite_set_rate,
+};
+
+static const struct clk_ops ti_composite_gate_ops = {
+ .enable = &omap2_dflt_clk_enable,
+ .disable = &omap2_dflt_clk_disable,
+ .is_enabled = &omap2_dflt_clk_is_enabled,
+};
+
+struct component_clk {
+ int num_parents;
+ const char **parent_names;
+ struct device_node *node;
+ int type;
+ struct clk_hw *hw;
+ struct list_head link;
+};
+
+static const char * __initdata component_clk_types[] = {
+ "mux", "gate", "divider",
+};
+
+static LIST_HEAD(component_clks);
+
+static struct component_clk *_lookup_component(struct device_node *node, int i)
+{
+ int rc;
+ struct of_phandle_args clkspec;
+ struct component_clk *comp;
+
+ rc = of_parse_phandle_with_args(node, "clocks", "#clock-cells", i,
+ &clkspec);
+ if (rc)
+ return NULL;
+
+ list_for_each_entry(comp, &component_clks, link) {
+ if (comp->node == clkspec.np)
+ return comp;
+ }
+ return NULL;
+}
+
+static inline struct clk_hw *_get_hw(struct component_clk *clk)
+{
+ if (clk)
+ return clk->hw;
+
+ return NULL;
+}
+
+static int __init of_ti_composite_clk_setup(struct device_node *node,
+ struct regmap *regmap)
+{
+ int num_clks;
+ int i;
+ struct clk *clk;
+ struct component_clk *comp;
+ struct component_clk *clks[3] = { NULL };
+ const char *name = node->name;
+ int num_parents = 0;
+ const char **parent_names = NULL;
+ int ret = 0;
+
+ /* Number of component clocks to be put inside this clock */
+ num_clks = of_clk_get_parent_count(node);
+
+ if (num_clks < 1) {
+ pr_err("%s: ti composite clk %s must have component(s)\n",
+ __func__, name);
+ return -EINVAL;
+ }
+
+ /* Check for presence of each component clock */
+ for (i = 0; i < num_clks; i++) {
+ comp = _lookup_component(node, i);
+ if (!comp)
+ return -EAGAIN;
+ if (clks[comp->type] != NULL) {
+ pr_err("%s: duplicate component types for %s (%s)!\n",
+ __func__, name, component_clk_types[comp->type]);
+ return -EINVAL;
+ }
+ clks[comp->type] = comp;
+ }
+
+ /* All components exists, proceed with registration */
+ for (i = 0; i < 3; i++) {
+ if (!clks[i])
+ continue;
+ if (clks[i]->num_parents) {
+ num_parents = clks[i]->num_parents;
+ parent_names = clks[i]->parent_names;
+ }
+ }
+
+ /* Enforce mux parents if exists */
+ comp = clks[CLK_COMPONENT_TYPE_MUX];
+ if (comp) {
+ num_parents = comp->num_parents;
+ parent_names = comp->parent_names;
+ }
+
+ if (!num_parents) {
+ pr_err("%s: no parents found for %s!\n", __func__,
+ name);
+ return -EINVAL;
+ }
+
+ clk = clk_register_composite(NULL, name, parent_names, num_parents,
+ _get_hw(clks[CLK_COMPONENT_TYPE_MUX]),
+ &clk_mux_ops,
+ _get_hw(clks[CLK_COMPONENT_TYPE_DIVIDER]),
+ &ti_composite_divider_ops,
+ _get_hw(clks[CLK_COMPONENT_TYPE_GATE]),
+ &ti_composite_gate_ops, 0);
+
+ if (!IS_ERR(clk)) {
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ goto cleanup;
+ }
+
+ ret = PTR_ERR(clk);
+cleanup:
+ /* Free component clock list entries */
+ for (i = 0; i < 3; i++) {
+ if (!clks[i])
+ continue;
+ list_del(&clks[i]->link);
+ kfree(clks[i]);
+ }
+
+ return ret;
+}
+CLK_OF_DECLARE(ti_composite_clock, "ti,composite-clock",
+ of_ti_composite_clk_setup);
+
+int __init ti_clk_add_component(struct device_node *node, struct clk_hw *hw,
+ int type)
+{
+ int num_parents;
+ const char **parent_names;
+ struct component_clk *clk;
+ int i;
+
+ num_parents = of_clk_get_parent_count(node);
+
+ if (num_parents < 1) {
+ pr_err("%s: component-clock %s must have parent(s)\n", __func__,
+ node->name);
+ return -EINVAL;
+ }
+
+ parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
+ if (!parent_names)
+ return -ENOMEM;
+
+ for (i = 0; i < num_parents; i++)
+ parent_names[i] = of_clk_get_parent_name(node, i);
+
+ clk = kzalloc(sizeof(*clk), GFP_KERNEL);
+ if (!clk) {
+ kfree(parent_names);
+ return -ENOMEM;
+ }
+
+ clk->num_parents = num_parents;
+ clk->parent_names = parent_names;
+ clk->hw = hw;
+ clk->node = node;
+ clk->type = type;
+ list_add(&clk->link, &component_clks);
+
+ return 0;
+}
diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
index e45005c..96c9725 100644
--- a/include/linux/clk/ti.h
+++ b/include/linux/clk/ti.h
@@ -137,6 +137,13 @@ struct clk_hw_omap {
/* DPLL Type and DCO Selection Flags */
#define DPLL_J_TYPE 0x1
+/* Composite clock component types */
+enum {
+ CLK_COMPONENT_TYPE_MUX = 0,
+ CLK_COMPONENT_TYPE_GATE,
+ CLK_COMPONENT_TYPE_DIVIDER
+};
+
/**
* struct ti_dt_clk - OMAP DT clock alias declarations
* @lk: clock lookup definition
@@ -179,6 +186,7 @@ int omap3_dpll4_set_rate(struct clk_hw *clk, unsigned long rate,
void ti_dt_clocks_register(struct ti_dt_clk *oclks);
void ti_dt_clk_init_provider(struct device_node *np, struct regmap *regmap);
int of_ti_autoidle_setup(struct device_node *node, struct regmap *regmap);
+int ti_clk_add_component(struct device_node *node, struct clk_hw *hw, int type);
#ifdef CONFIG_OF
void of_ti_clk_allow_autoidle_all(void);
--
1.7.9.5
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