1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * 4 * Copyright (C) 2012 ARM Limited 5 */ 6 7 #include <linux/clkdev.h> 8 #include <linux/clk-provider.h> 9 #include <linux/err.h> 10 #include <linux/of.h> 11 #include <linux/platform_device.h> 12 #include <linux/slab.h> 13 #include <linux/vexpress.h> 14 15 struct vexpress_osc { 16 struct regmap *reg; 17 struct clk_hw hw; 18 unsigned long rate_min; 19 unsigned long rate_max; 20 }; 21 22 #define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw) 23 24 static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw, 25 unsigned long parent_rate) 26 { 27 struct vexpress_osc *osc = to_vexpress_osc(hw); 28 u32 rate; 29 30 regmap_read(osc->reg, 0, &rate); 31 32 return rate; 33 } 34 35 static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate, 36 unsigned long *parent_rate) 37 { 38 struct vexpress_osc *osc = to_vexpress_osc(hw); 39 40 if (osc->rate_min && rate < osc->rate_min) 41 rate = osc->rate_min; 42 43 if (osc->rate_max && rate > osc->rate_max) 44 rate = osc->rate_max; 45 46 return rate; 47 } 48 49 static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate, 50 unsigned long parent_rate) 51 { 52 struct vexpress_osc *osc = to_vexpress_osc(hw); 53 54 return regmap_write(osc->reg, 0, rate); 55 } 56 57 static const struct clk_ops vexpress_osc_ops = { 58 .recalc_rate = vexpress_osc_recalc_rate, 59 .round_rate = vexpress_osc_round_rate, 60 .set_rate = vexpress_osc_set_rate, 61 }; 62 63 64 static int vexpress_osc_probe(struct platform_device *pdev) 65 { 66 struct clk_init_data init; 67 struct vexpress_osc *osc; 68 struct clk *clk; 69 u32 range[2]; 70 71 osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL); 72 if (!osc) 73 return -ENOMEM; 74 75 osc->reg = devm_regmap_init_vexpress_config(&pdev->dev); 76 if (IS_ERR(osc->reg)) 77 return PTR_ERR(osc->reg); 78 79 if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range, 80 ARRAY_SIZE(range)) == 0) { 81 osc->rate_min = range[0]; 82 osc->rate_max = range[1]; 83 } 84 85 if (of_property_read_string(pdev->dev.of_node, "clock-output-names", 86 &init.name) != 0) 87 init.name = dev_name(&pdev->dev); 88 89 init.ops = &vexpress_osc_ops; 90 init.flags = 0; 91 init.num_parents = 0; 92 93 osc->hw.init = &init; 94 95 clk = clk_register(NULL, &osc->hw); 96 if (IS_ERR(clk)) 97 return PTR_ERR(clk); 98 99 of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get, clk); 100 clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max); 101 102 dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name); 103 104 return 0; 105 } 106 107 static const struct of_device_id vexpress_osc_of_match[] = { 108 { .compatible = "arm,vexpress-osc", }, 109 {} 110 }; 111 112 static struct platform_driver vexpress_osc_driver = { 113 .driver = { 114 .name = "vexpress-osc", 115 .of_match_table = vexpress_osc_of_match, 116 }, 117 .probe = vexpress_osc_probe, 118 }; 119 120 static int __init vexpress_osc_init(void) 121 { 122 return platform_driver_register(&vexpress_osc_driver); 123 } 124 core_initcall(vexpress_osc_init); 125