ed27ff1db8
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>
146 lines
3.3 KiB
C
146 lines
3.3 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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#define pr_fmt(fmt) "vexpress-osc: " fmt
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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 vexpress_config_func *func;
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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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vexpress_config_read(osc->func, 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 (WARN_ON(osc->rate_min && rate < osc->rate_min))
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rate = osc->rate_min;
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if (WARN_ON(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 vexpress_config_write(osc->func, 0, rate);
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}
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static 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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struct clk * __init vexpress_osc_setup(struct device *dev)
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{
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struct clk_init_data init;
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struct vexpress_osc *osc = kzalloc(sizeof(*osc), GFP_KERNEL);
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if (!osc)
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return NULL;
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osc->func = vexpress_config_func_get_by_dev(dev);
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if (!osc->func) {
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kfree(osc);
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return NULL;
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}
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init.name = dev_name(dev);
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init.ops = &vexpress_osc_ops;
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init.flags = CLK_IS_ROOT;
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init.num_parents = 0;
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osc->hw.init = &init;
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return clk_register(NULL, &osc->hw);
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}
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void __init vexpress_osc_of_setup(struct device_node *node)
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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 = kzalloc(sizeof(*osc), GFP_KERNEL);
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if (!osc)
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goto error;
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osc->func = vexpress_config_func_get_by_node(node);
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if (!osc->func) {
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pr_err("Failed to obtain config func for node '%s'!\n",
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node->name);
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goto error;
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}
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if (of_property_read_u32_array(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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of_property_read_string(node, "clock-output-names", &init.name);
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if (!init.name)
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init.name = node->name;
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init.ops = &vexpress_osc_ops;
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init.flags = CLK_IS_ROOT;
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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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pr_err("Failed to register clock '%s'!\n", init.name);
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goto error;
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}
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of_clk_add_provider(node, of_clk_src_simple_get, clk);
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pr_debug("Registered clock '%s'\n", init.name);
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return;
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error:
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if (osc->func)
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vexpress_config_func_put(osc->func);
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kfree(osc);
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}
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