clk: ti: add support for TI fixed factor clock
authorTero Kristo <t-kristo@ti.com>
Fri, 13 Sep 2013 11:57:59 +0000 (14:57 +0300)
committerMike Turquette <mturquette@linaro.org>
Fri, 17 Jan 2014 20:35:07 +0000 (12:35 -0800)
This behaves exactly in similar manner to basic fixed-factor-clock, but
adds a few properties on top for handling clock hardware autoidling.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt [new file with mode: 0644]
drivers/clk/ti/Makefile
drivers/clk/ti/fixed-factor.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt b/Documentation/devicetree/bindings/clock/ti/fixed-factor-clock.txt
new file mode 100644 (file)
index 0000000..662b36d
--- /dev/null
@@ -0,0 +1,43 @@
+Binding for TI fixed factor rate clock sources.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1], and also uses the autoidle
+support from TI autoidle clock [2].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Documentation/devicetree/bindings/clock/ti/autoidle.txt
+
+Required properties:
+- compatible : shall be "ti,fixed-factor-clock".
+- #clock-cells : from common clock binding; shall be set to 0.
+- ti,clock-div: fixed divider.
+- ti,clock-mult: fixed multiplier.
+- clocks: parent clock.
+
+Optional properties:
+- ti,autoidle-shift: bit shift of the autoidle enable bit for the clock,
+  see [2]
+- reg: offset for the autoidle register of this clock, see [2]
+- ti,invert-autoidle-bit: autoidle is enabled by setting the bit to 0, see [2]
+- ti,set-rate-parent: clk_set_rate is propagated to parent
+
+Example:
+       clock {
+               compatible = "ti,fixed-factor-clock";
+               clocks = <&parentclk>;
+               #clock-cells = <0>;
+               ti,clock-div = <2>;
+               ti,clock-mult = <1>;
+       };
+
+       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;
+       };
index 8690b0b442c0ecfbd90a404bd622c6feaed62c29..d3586252a391449ee60aa2f4d75d8789ab33ef21 100644 (file)
@@ -1,4 +1,5 @@
 ifneq ($(CONFIG_OF),)
 obj-y                                  += clk.o autoidle.o
-clk-common                             = dpll.o composite.o divider.o
+clk-common                             = dpll.o composite.o divider.o \
+                                         fixed-factor.o
 endif
diff --git a/drivers/clk/ti/fixed-factor.c b/drivers/clk/ti/fixed-factor.c
new file mode 100644 (file)
index 0000000..c2c8a28
--- /dev/null
@@ -0,0 +1,66 @@
+/*
+ * TI Fixed Factor Clock
+ *
+ * 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/err.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__
+
+/**
+ * of_ti_fixed_factor_clk_setup - Setup function for TI fixed factor clock
+ * @node: device node for this clock
+ *
+ * Sets up a simple fixed factor clock based on device tree info.
+ */
+static void __init of_ti_fixed_factor_clk_setup(struct device_node *node)
+{
+       struct clk *clk;
+       const char *clk_name = node->name;
+       const char *parent_name;
+       u32 div, mult;
+       u32 flags = 0;
+
+       if (of_property_read_u32(node, "ti,clock-div", &div)) {
+               pr_err("%s must have a clock-div property\n", node->name);
+               return;
+       }
+
+       if (of_property_read_u32(node, "ti,clock-mult", &mult)) {
+               pr_err("%s must have a clock-mult property\n", node->name);
+               return;
+       }
+
+       if (of_property_read_bool(node, "ti,set-rate-parent"))
+               flags |= CLK_SET_RATE_PARENT;
+
+       parent_name = of_clk_get_parent_name(node, 0);
+
+       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, flags,
+                                       mult, div);
+
+       if (!IS_ERR(clk)) {
+               of_clk_add_provider(node, of_clk_src_simple_get, clk);
+               of_ti_clk_autoidle_setup(node);
+       }
+}
+CLK_OF_DECLARE(ti_fixed_factor_clk, "ti,fixed-factor-clock",
+              of_ti_fixed_factor_clk_setup);