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authorPawel Moll <pawel.moll@arm.com>2012-09-18 15:17:47 +0100
committerMike Turquette <mturquette@linaro.org>2012-10-29 11:07:51 -0700
commited27ff1db869cc81a92bed6defb7d107f5a156ff (patch)
tree635223b21f41fbda49ce9fc917ce5334574f59f9 /drivers/clk/versatile
parentf9f8c0438da2c6d6a4cd8af73097add3850d6084 (diff)
downloadvexpress-lsk-ed27ff1db869cc81a92bed6defb7d107f5a156ff.tar.gz
clk: Versatile Express clock generators ("osc") driver
This driver provides a common clock framework hardware driver for Versatile Express clock generators (a.k.a "osc") controlled via the config bus. Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/versatile')
-rw-r--r--drivers/clk/versatile/Makefile1
-rw-r--r--drivers/clk/versatile/clk-vexpress-osc.c146
2 files changed, 147 insertions, 0 deletions
diff --git a/drivers/clk/versatile/Makefile b/drivers/clk/versatile/Makefile
index c0a0f647879..1e49a7afcf4 100644
--- a/drivers/clk/versatile/Makefile
+++ b/drivers/clk/versatile/Makefile
@@ -2,3 +2,4 @@
obj-$(CONFIG_ICST) += clk-icst.o
obj-$(CONFIG_ARCH_INTEGRATOR) += clk-integrator.o
obj-$(CONFIG_ARCH_REALVIEW) += clk-realview.o
+obj-$(CONFIG_VEXPRESS_CONFIG) += clk-vexpress-osc.o
diff --git a/drivers/clk/versatile/clk-vexpress-osc.c b/drivers/clk/versatile/clk-vexpress-osc.c
new file mode 100644
index 00000000000..dcb6ae0a042
--- /dev/null
+++ b/drivers/clk/versatile/clk-vexpress-osc.c
@@ -0,0 +1,146 @@
+/*
+ * 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 in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#define pr_fmt(fmt) "vexpress-osc: " fmt
+
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/vexpress.h>
+
+struct vexpress_osc {
+ struct vexpress_config_func *func;
+ struct clk_hw hw;
+ unsigned long rate_min;
+ unsigned long rate_max;
+};
+
+#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
+
+static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct vexpress_osc *osc = to_vexpress_osc(hw);
+ u32 rate;
+
+ vexpress_config_read(osc->func, 0, &rate);
+
+ return rate;
+}
+
+static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct vexpress_osc *osc = to_vexpress_osc(hw);
+
+ if (WARN_ON(osc->rate_min && rate < osc->rate_min))
+ rate = osc->rate_min;
+
+ if (WARN_ON(osc->rate_max && rate > osc->rate_max))
+ rate = osc->rate_max;
+
+ return rate;
+}
+
+static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct vexpress_osc *osc = to_vexpress_osc(hw);
+
+ return vexpress_config_write(osc->func, 0, rate);
+}
+
+static struct clk_ops vexpress_osc_ops = {
+ .recalc_rate = vexpress_osc_recalc_rate,
+ .round_rate = vexpress_osc_round_rate,
+ .set_rate = vexpress_osc_set_rate,
+};
+
+
+struct clk * __init vexpress_osc_setup(struct device *dev)
+{
+ struct clk_init_data init;
+ struct vexpress_osc *osc = kzalloc(sizeof(*osc), GFP_KERNEL);
+
+ if (!osc)
+ return NULL;
+
+ osc->func = vexpress_config_func_get_by_dev(dev);
+ if (!osc->func) {
+ kfree(osc);
+ return NULL;
+ }
+
+ init.name = dev_name(dev);
+ init.ops = &vexpress_osc_ops;
+ init.flags = CLK_IS_ROOT;
+ init.num_parents = 0;
+ osc->hw.init = &init;
+
+ return clk_register(NULL, &osc->hw);
+}
+
+void __init vexpress_osc_of_setup(struct device_node *node)
+{
+ struct clk_init_data init;
+ struct vexpress_osc *osc;
+ struct clk *clk;
+ u32 range[2];
+
+ osc = kzalloc(sizeof(*osc), GFP_KERNEL);
+ if (!osc)
+ goto error;
+
+ osc->func = vexpress_config_func_get_by_node(node);
+ if (!osc->func) {
+ pr_err("Failed to obtain config func for node '%s'!\n",
+ node->name);
+ goto error;
+ }
+
+ if (of_property_read_u32_array(node, "freq-range", range,
+ ARRAY_SIZE(range)) == 0) {
+ osc->rate_min = range[0];
+ osc->rate_max = range[1];
+ }
+
+ of_property_read_string(node, "clock-output-names", &init.name);
+ if (!init.name)
+ init.name = node->name;
+
+ init.ops = &vexpress_osc_ops;
+ init.flags = CLK_IS_ROOT;
+ init.num_parents = 0;
+
+ osc->hw.init = &init;
+
+ clk = clk_register(NULL, &osc->hw);
+ if (IS_ERR(clk)) {
+ pr_err("Failed to register clock '%s'!\n", init.name);
+ goto error;
+ }
+
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+ pr_debug("Registered clock '%s'\n", init.name);
+
+ return;
+
+error:
+ if (osc->func)
+ vexpress_config_func_put(osc->func);
+ kfree(osc);
+}