132 lines
3.1 KiB
C
132 lines
3.1 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* Copyright (C) 2012 ARM Limited
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*/
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#include <linux/clkdev.h>
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#include <linux/clk-provider.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/vexpress.h>
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struct vexpress_osc {
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struct regmap *reg;
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struct clk_hw hw;
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unsigned long rate_min;
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unsigned long rate_max;
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};
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#define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
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static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct vexpress_osc *osc = to_vexpress_osc(hw);
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u32 rate;
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regmap_read(osc->reg, 0, &rate);
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return rate;
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}
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static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long *parent_rate)
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{
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struct vexpress_osc *osc = to_vexpress_osc(hw);
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if (osc->rate_min && rate < osc->rate_min)
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rate = osc->rate_min;
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if (osc->rate_max && rate > osc->rate_max)
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rate = osc->rate_max;
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return rate;
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}
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static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct vexpress_osc *osc = to_vexpress_osc(hw);
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return regmap_write(osc->reg, 0, rate);
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}
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static const struct clk_ops vexpress_osc_ops = {
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.recalc_rate = vexpress_osc_recalc_rate,
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.round_rate = vexpress_osc_round_rate,
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.set_rate = vexpress_osc_set_rate,
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};
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static int vexpress_osc_probe(struct platform_device *pdev)
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{
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struct clk_init_data init = {};
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struct vexpress_osc *osc;
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struct clk *clk;
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u32 range[2];
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osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
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if (!osc)
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return -ENOMEM;
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osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
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if (IS_ERR(osc->reg))
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return PTR_ERR(osc->reg);
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if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
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ARRAY_SIZE(range)) == 0) {
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osc->rate_min = range[0];
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osc->rate_max = range[1];
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}
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if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
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&init.name) != 0)
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init.name = dev_name(&pdev->dev);
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init.ops = &vexpress_osc_ops;
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init.flags = 0;
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init.num_parents = 0;
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osc->hw.init = &init;
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clk = clk_register(NULL, &osc->hw);
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if (IS_ERR(clk))
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return PTR_ERR(clk);
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of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk);
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clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max);
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dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
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return 0;
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}
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static const struct of_device_id vexpress_osc_of_match[] = {
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{ .compatible = "arm,vexpress-osc", },
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{}
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};
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static struct platform_driver vexpress_osc_driver = {
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.driver = {
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.name = "vexpress-osc",
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.of_match_table = vexpress_osc_of_match,
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},
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.probe = vexpress_osc_probe,
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};
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static int __init vexpress_osc_init(void)
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{
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return platform_driver_register(&vexpress_osc_driver);
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}
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core_initcall(vexpress_osc_init);
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