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/module.h> 11 #include <linux/of.h> 12 #include <linux/platform_device.h> 13 #include <linux/slab.h> 14 #include <linux/vexpress.h> 15 16 struct vexpress_osc { 17 struct regmap *reg; 18 struct clk_hw hw; 19 unsigned long rate_min; 20 unsigned long rate_max; 21 }; 22 23 #define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw) 24 25 static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw, 26 unsigned long parent_rate) 27 { 28 struct vexpress_osc *osc = to_vexpress_osc(hw); 29 u32 rate; 30 31 regmap_read(osc->reg, 0, &rate); 32 33 return rate; 34 } 35 36 static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate, 37 unsigned long *parent_rate) 38 { 39 struct vexpress_osc *osc = to_vexpress_osc(hw); 40 41 if (osc->rate_min && rate < osc->rate_min) 42 rate = osc->rate_min; 43 44 if (osc->rate_max && rate > osc->rate_max) 45 rate = osc->rate_max; 46 47 return rate; 48 } 49 50 static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate, 51 unsigned long parent_rate) 52 { 53 struct vexpress_osc *osc = to_vexpress_osc(hw); 54 55 return regmap_write(osc->reg, 0, rate); 56 } 57 58 static const struct clk_ops vexpress_osc_ops = { 59 .recalc_rate = vexpress_osc_recalc_rate, 60 .round_rate = vexpress_osc_round_rate, 61 .set_rate = vexpress_osc_set_rate, 62 }; 63 64 65 static int vexpress_osc_probe(struct platform_device *pdev) 66 { 67 struct clk_init_data init; 68 struct vexpress_osc *osc; 69 u32 range[2]; 70 int ret; 71 72 osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL); 73 if (!osc) 74 return -ENOMEM; 75 76 osc->reg = devm_regmap_init_vexpress_config(&pdev->dev); 77 if (IS_ERR(osc->reg)) 78 return PTR_ERR(osc->reg); 79 80 if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range, 81 ARRAY_SIZE(range)) == 0) { 82 osc->rate_min = range[0]; 83 osc->rate_max = range[1]; 84 } 85 86 if (of_property_read_string(pdev->dev.of_node, "clock-output-names", 87 &init.name) != 0) 88 init.name = dev_name(&pdev->dev); 89 90 init.ops = &vexpress_osc_ops; 91 init.flags = 0; 92 init.num_parents = 0; 93 94 osc->hw.init = &init; 95 96 ret = devm_clk_hw_register(&pdev->dev, &osc->hw); 97 if (ret < 0) 98 return ret; 99 100 devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, &osc->hw); 101 clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max); 102 103 dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name); 104 105 return 0; 106 } 107 108 static const struct of_device_id vexpress_osc_of_match[] = { 109 { .compatible = "arm,vexpress-osc", }, 110 {} 111 }; 112 MODULE_DEVICE_TABLE(of, vexpress_osc_of_match); 113 114 static struct platform_driver vexpress_osc_driver = { 115 .driver = { 116 .name = "vexpress-osc", 117 .of_match_table = vexpress_osc_of_match, 118 }, 119 .probe = vexpress_osc_probe, 120 }; 121 module_platform_driver(vexpress_osc_driver); 122 MODULE_LICENSE("GPL v2"); 123