/* * 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_lookup *cl = pdev->dev.platform_data; /* Non-DT lookup */ 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); /* Only happens for non-DT cases */ if (cl) { cl->clk = clk; clkdev_add(cl); } dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name); return 0; } static 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);