clk: ti: add composite clock support
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@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/ti/composite.c b/drivers/clk/ti/composite.c
new file mode 100644
index 0000000..6539b65
--- /dev/null
+++ b/drivers/clk/ti/composite.c
@@ -0,0 +1,269 @@
+/*
+ * TI composite clock 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>
+#include <linux/clk/ti.h>
+#include <linux/list.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#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 * __initconst component_clk_types[] = {
+ "gate", "divider", "mux"
+};
+
+static LIST_HEAD(component_clks);
+
+static struct device_node *_get_component_node(struct device_node *node, int i)
+{
+ int rc;
+ struct of_phandle_args clkspec;
+
+ rc = of_parse_phandle_with_args(node, "clocks", "#clock-cells", i,
+ &clkspec);
+ if (rc)
+ return NULL;
+
+ return clkspec.np;
+}
+
+static struct component_clk *_lookup_component(struct device_node *node)
+{
+ struct component_clk *comp;
+
+ list_for_each_entry(comp, &component_clks, link) {
+ if (comp->node == node)
+ return comp;
+ }
+ return NULL;
+}
+
+struct clk_hw_omap_comp {
+ struct clk_hw hw;
+ struct device_node *comp_nodes[CLK_COMPONENT_TYPE_MAX];
+ struct component_clk *comp_clks[CLK_COMPONENT_TYPE_MAX];
+};
+
+static inline struct clk_hw *_get_hw(struct clk_hw_omap_comp *clk, int idx)
+{
+ if (!clk)
+ return NULL;
+
+ if (!clk->comp_clks[idx])
+ return NULL;
+
+ return clk->comp_clks[idx]->hw;
+}
+
+#define to_clk_hw_comp(_hw) container_of(_hw, struct clk_hw_omap_comp, hw)
+
+static void __init ti_clk_register_composite(struct clk_hw *hw,
+ struct device_node *node)
+{
+ struct clk *clk;
+ struct clk_hw_omap_comp *cclk = to_clk_hw_comp(hw);
+ struct component_clk *comp;
+ int num_parents = 0;
+ const char **parent_names = NULL;
+ int i;
+
+ /* Check for presence of each component clock */
+ for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
+ if (!cclk->comp_nodes[i])
+ continue;
+
+ comp = _lookup_component(cclk->comp_nodes[i]);
+ if (!comp) {
+ pr_debug("component %s not ready for %s, retry\n",
+ cclk->comp_nodes[i]->name, node->name);
+ if (!ti_clk_retry_init(node, hw,
+ ti_clk_register_composite))
+ return;
+
+ goto cleanup;
+ }
+ if (cclk->comp_clks[comp->type] != NULL) {
+ pr_err("duplicate component types for %s (%s)!\n",
+ node->name, component_clk_types[comp->type]);
+ goto cleanup;
+ }
+
+ cclk->comp_clks[comp->type] = comp;
+
+ /* Mark this node as found */
+ cclk->comp_nodes[i] = NULL;
+ }
+
+ /* All components exists, proceed with registration */
+ for (i = CLK_COMPONENT_TYPE_MAX - 1; i >= 0; i--) {
+ comp = cclk->comp_clks[i];
+ if (!comp)
+ continue;
+ if (comp->num_parents) {
+ num_parents = comp->num_parents;
+ parent_names = comp->parent_names;
+ break;
+ }
+ }
+
+ if (!num_parents) {
+ pr_err("%s: no parents found for %s!\n", __func__, node->name);
+ goto cleanup;
+ }
+
+ clk = clk_register_composite(NULL, node->name,
+ parent_names, num_parents,
+ _get_hw(cclk, CLK_COMPONENT_TYPE_MUX),
+ &clk_mux_ops,
+ _get_hw(cclk, CLK_COMPONENT_TYPE_DIVIDER),
+ &ti_composite_divider_ops,
+ _get_hw(cclk, CLK_COMPONENT_TYPE_GATE),
+ &ti_composite_gate_ops, 0);
+
+ if (!IS_ERR(clk))
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+cleanup:
+ /* Free component clock list entries */
+ for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
+ if (!cclk->comp_clks[i])
+ continue;
+ list_del(&cclk->comp_clks[i]->link);
+ kfree(cclk->comp_clks[i]);
+ }
+
+ kfree(cclk);
+}
+
+static void __init of_ti_composite_clk_setup(struct device_node *node)
+{
+ int num_clks;
+ int i;
+ struct clk_hw_omap_comp *cclk;
+
+ /* Number of component clocks to be put inside this clock */
+ num_clks = of_clk_get_parent_count(node);
+
+ if (num_clks < 1) {
+ pr_err("composite clk %s must have component(s)\n", node->name);
+ return;
+ }
+
+ cclk = kzalloc(sizeof(*cclk), GFP_KERNEL);
+ if (!cclk)
+ return;
+
+ /* Get device node pointers for each component clock */
+ for (i = 0; i < num_clks; i++)
+ cclk->comp_nodes[i] = _get_component_node(node, i);
+
+ ti_clk_register_composite(&cclk->hw, node);
+}
+CLK_OF_DECLARE(ti_composite_clock, "ti,composite-clock",
+ of_ti_composite_clk_setup);
+
+/**
+ * ti_clk_add_component - add a component clock to the pool
+ * @node: device node of the component clock
+ * @hw: hardware clock definition for the component clock
+ * @type: type of the component clock
+ *
+ * Adds a component clock to the list of available components, so that
+ * it can be registered by a composite clock.
+ */
+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("component-clock %s must have parent(s)\n", 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;
+}