Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / clk / versatile / clk-vexpress-osc.c

diff --git a/kernel/drivers/clk/versatile/clk-vexpress-osc.c b/kernel/drivers/clk/versatile/clk-vexpress-osc.c
new file mode 100644 (file)
index 0000000..89c0609
--- /dev/null
+++ b/kernel/drivers/clk/versatile/clk-vexpress-osc.c
@@ -0,0 +1,130 @@
+/*
+ * 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
+ */
+
+#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 regmap *reg;
+       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;
+
+       regmap_read(osc->reg, 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 regmap_write(osc->reg, 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,
+};
+
+
+static int vexpress_osc_probe(struct platform_device *pdev)
+{
+       struct clk_init_data init;
+       struct vexpress_osc *osc;
+       struct clk *clk;
+       u32 range[2];
+
+       osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
+       if (!osc)
+               return -ENOMEM;
+
+       osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
+       if (IS_ERR(osc->reg))
+               return PTR_ERR(osc->reg);
+
+       if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
+                       ARRAY_SIZE(range)) == 0) {
+               osc->rate_min = range[0];
+               osc->rate_max = range[1];
+       }
+
+       if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
+                       &init.name) != 0)
+               init.name = dev_name(&pdev->dev);
+
+       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))
+               return PTR_ERR(clk);
+
+       of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk);
+
+       dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
+
+       return 0;
+}
+
+static const struct of_device_id vexpress_osc_of_match[] = {
+       { .compatible = "arm,vexpress-osc", },
+       {}
+};
+
+static struct platform_driver vexpress_osc_driver = {
+       .driver = {
+               .name = "vexpress-osc",
+               .of_match_table = vexpress_osc_of_match,
+       },
+       .probe = vexpress_osc_probe,
+};
+
+static int __init vexpress_osc_init(void)
+{
+       return platform_driver_register(&vexpress_osc_driver);
+}
+core_initcall(vexpress_osc_init);