CLK: TI: add support for clockdomain binding

Some OMAP clocks require knowledge about their parent clockdomain for
book keeping purposes. This patch creates a new DT binding for TI
clockdomains, which act as a collection of device clocks. Clockdomain
itself is rather misleading name for the hardware functionality, as at
least on OMAP4 / OMAP5 / DRA7 the clockdomains can be collections of either
clocks and/or IP blocks, thus idle-domain or such might be more appropriate.
For most cases on these SoCs, the kernel doesn't even need the information
and the mappings can be ignored.

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/Documentation/devicetree/bindings/clock/ti/clockdomain.txt b/Documentation/devicetree/bindings/clock/ti/clockdomain.txt
new file mode 100644 (file)
index 0000000..cb76b3f
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/clockdomain.txt
@@ -0,0 +1,24 @@
+Binding for Texas Instruments clockdomain.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1] in consumer role.
+Every clock on TI SoC belongs to one clockdomain, but software
+only needs this information for specific clocks which require
+their parent clockdomain to be controlled when the clock is
+enabled/disabled. This binding doesn't define a new clock
+binding type, it is used to group existing clock nodes under
+hardware hierarchy.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "ti,clockdomain"
+- #clock-cells : from common clock binding; shall be set to 0.
+- clocks : link phandles of clocks within this domain
+
+Examples:
+       dss_clkdm: dss_clkdm {
+               compatible = "ti,clockdomain";
+               clocks = <&dss1_alwon_fck_3430es2>, <&dss_ick_3430es2>;
+       };

diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile
index eaa6dc0..ae7cd1e 100644 (file)
--- a/drivers/clk/ti/Makefile
+++ b/drivers/clk/ti/Makefile
@@ -1,5 +1,5 @@
 ifneq ($(CONFIG_OF),)
-obj-y                                  += clk.o autoidle.o
+obj-y                                  += clk.o autoidle.o clockdomain.o
 clk-common                             = dpll.o composite.o divider.o gate.o \
                                          fixed-factor.o
 endif

diff --git a/drivers/clk/ti/clockdomain.c b/drivers/clk/ti/clockdomain.c
new file mode 100644 (file)
index 0000000..f1e0038
--- /dev/null
+++ b/drivers/clk/ti/clockdomain.c
@@ -0,0 +1,70 @@
+/*
+ * OMAP clockdomain 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/of.h>
+#include <linux/of_address.h>
+#include <linux/clk/ti.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+static void __init of_ti_clockdomain_setup(struct device_node *node)
+{
+       struct clk *clk;
+       struct clk_hw *clk_hw;
+       const char *clkdm_name = node->name;
+       int i;
+       int num_clks;
+
+       num_clks = of_count_phandle_with_args(node, "clocks", "#clock-cells");
+
+       for (i = 0; i < num_clks; i++) {
+               clk = of_clk_get(node, i);
+               if (__clk_get_flags(clk) & CLK_IS_BASIC) {
+                       pr_warn("can't setup clkdm for basic clk %s\n",
+                               __clk_get_name(clk));
+                       continue;
+               }
+               clk_hw = __clk_get_hw(clk);
+               to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name;
+               omap2_init_clk_clkdm(clk_hw);
+       }
+}
+
+static struct of_device_id ti_clkdm_match_table[] __initdata = {
+       { .compatible = "ti,clockdomain" },
+       { }
+};
+
+/**
+ * ti_dt_clockdomains_setup - setup device tree clockdomains
+ *
+ * Initializes clockdomain nodes for a SoC. This parses through all the
+ * nodes with compatible = "ti,clockdomain", and add the clockdomain
+ * info for all the clocks listed under these. This function shall be
+ * called after rest of the DT clock init has completed and all
+ * clock nodes have been registered.
+ */
+void __init ti_dt_clockdomains_setup(void)
+{
+       struct device_node *np;
+       for_each_matching_node(np, ti_clkdm_match_table) {
+               of_ti_clockdomain_setup(np);
+       }
+}

diff --git a/include/linux/clk/ti.h b/include/linux/clk/ti.h
index d94feb3..a3f89a6 100644 (file)
--- a/include/linux/clk/ti.h
+++ b/include/linux/clk/ti.h
@@ -255,6 +255,7 @@ int omap2_dflt_clk_is_enabled(struct clk_hw *hw);
 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);
+void ti_dt_clockdomains_setup(void);
 int ti_clk_retry_init(struct device_node *node, struct clk_hw *hw,
                      ti_of_clk_init_cb_t func);
 int of_ti_clk_autoidle_setup(struct device_node *node);