This patch adds MOXA ART SoCs clock driver support.
Signed-off-by: Jonas Jensen <jonas.jen...@gmail.com>
---
Notes:
Changes since v5:
1. corrected of_iomap return value check
2. don't panic, print the error and return
Applies to next-20130729
.../bindings/clock/moxa,moxart-core-clock.txt | 23 +++++++
drivers/clk/Makefile | 1 +
drivers/clk/clk-moxart.c | 71 ++++++++++++++++++++++
3 files changed, 95 insertions(+)
create mode 100644
Documentation/devicetree/bindings/clock/moxa,moxart-core-clock.txt
create mode 100644 drivers/clk/clk-moxart.c
diff --git a/Documentation/devicetree/bindings/clock/moxa,moxart-core-clock.txt
b/Documentation/devicetree/bindings/clock/moxa,moxart-core-clock.txt
new file mode 100644
index 0000000..379ae79
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/moxa,moxart-core-clock.txt
@@ -0,0 +1,23 @@
+Device Tree Clock bindings for arch-moxart
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+MOXA ART SoCs allow to determine core clock frequencies by reading
+a register.
+
+Required properties:
+- compatible : Must be "moxa,moxart-core-clock"
+- #clock-cells : Should be 0
+- reg : Should contain registers location and length
+- clock-output-names : Should be "coreclk"
+
+For example:
+
+ coreclk: core-clock@98100000 {
+ compatible = "moxa,moxart-core-clock";
+ #clock-cells = <0>;
+ reg = <0x98100000 0x34>;
+ clock-output-names = "coreclk";
+ };
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 4038c2b..933622f 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_COMMON_CLK) += clk-composite.o
# SoCs specific
obj-$(CONFIG_ARCH_BCM2835) += clk-bcm2835.o
+obj-$(CONFIG_ARCH_MOXART) += clk-moxart.o
obj-$(CONFIG_ARCH_NOMADIK) += clk-nomadik.o
obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
obj-$(CONFIG_ARCH_NSPIRE) += clk-nspire.o
diff --git a/drivers/clk/clk-moxart.c b/drivers/clk/clk-moxart.c
new file mode 100644
index 0000000..14d5b26
--- /dev/null
+++ b/drivers/clk/clk-moxart.c
@@ -0,0 +1,71 @@
+/*
+ * MOXA ART SoCs clock driver.
+ *
+ * Copyright (C) 2013 Jonas Jensen
+ *
+ * Jonas Jensen <jonas.jen...@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/clkdev.h>
+
+void __init moxart_of_clk_init(struct device_node *node)
+{
+ static void __iomem *base;
+ struct clk *clk;
+ unsigned long rate;
+ unsigned int mul, val, div;
+ const char *name;
+
+ base = of_iomap(node, 0);
+ if (!base) {
+ pr_err("%s: of_iomap failed\n", node->full_name);
+ return;
+ }
+
+ mul = (readl(base + 0x30) >> 3) & 0x1ff;
+ val = (readl(base + 0x0c) >> 4) & 0x7;
+
+ switch (val) {
+ case 1:
+ div = 3;
+ break;
+ case 2:
+ div = 4;
+ break;
+ case 3:
+ div = 6;
+ break;
+ case 4:
+ div = 8;
+ break;
+ default:
+ div = 2;
+ break;
+ }
+
+ /*
+ * the rate calculation below is only tested and proven
+ * to be true for UC-7112-LX
+ *
+ * UC-7112-LX: mul=80 val=0
+ *
+ * to support other moxart SoC hardware, this may need
+ * a change, though it's possible it works there too
+ */
+ rate = (mul * 1200000 / div);
+
+ of_property_read_string(node, "clock-output-names", &name);
+ clk = clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);
+ clk_register_clkdev(clk, NULL, name);
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+ iounmap(base);
+}
+CLK_OF_DECLARE(moxart_core_clock, "moxa,moxart-core-clock",
moxart_of_clk_init);
--
1.8.2.1
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