1 /* 2 * Clock driver for Hi655x 3 * 4 * Copyright (c) 2017, Linaro Ltd. 5 * 6 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms and conditions of the GNU General Public License, 10 * version 2, as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 15 * more details. 16 */ 17 #include <linux/clk-provider.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 #include <linux/regmap.h> 21 #include <linux/slab.h> 22 #include <linux/mfd/core.h> 23 #include <linux/mfd/hi655x-pmic.h> 24 25 #define HI655X_CLK_BASE HI655X_BUS_ADDR(0x1c) 26 #define HI655X_CLK_SET BIT(6) 27 28 struct hi655x_clk { 29 struct hi655x_pmic *hi655x; 30 struct clk_hw clk_hw; 31 }; 32 33 static unsigned long hi655x_clk_recalc_rate(struct clk_hw *hw, 34 unsigned long parent_rate) 35 { 36 return 32768; 37 } 38 39 static int hi655x_clk_enable(struct clk_hw *hw, bool enable) 40 { 41 struct hi655x_clk *hi655x_clk = 42 container_of(hw, struct hi655x_clk, clk_hw); 43 44 struct hi655x_pmic *hi655x = hi655x_clk->hi655x; 45 46 return regmap_update_bits(hi655x->regmap, HI655X_CLK_BASE, 47 HI655X_CLK_SET, enable ? HI655X_CLK_SET : 0); 48 } 49 50 static int hi655x_clk_prepare(struct clk_hw *hw) 51 { 52 return hi655x_clk_enable(hw, true); 53 } 54 55 static void hi655x_clk_unprepare(struct clk_hw *hw) 56 { 57 hi655x_clk_enable(hw, false); 58 } 59 60 static int hi655x_clk_is_prepared(struct clk_hw *hw) 61 { 62 struct hi655x_clk *hi655x_clk = 63 container_of(hw, struct hi655x_clk, clk_hw); 64 struct hi655x_pmic *hi655x = hi655x_clk->hi655x; 65 int ret; 66 uint32_t val; 67 68 ret = regmap_read(hi655x->regmap, HI655X_CLK_BASE, &val); 69 if (ret < 0) 70 return ret; 71 72 return val & HI655X_CLK_BASE; 73 } 74 75 static const struct clk_ops hi655x_clk_ops = { 76 .prepare = hi655x_clk_prepare, 77 .unprepare = hi655x_clk_unprepare, 78 .is_prepared = hi655x_clk_is_prepared, 79 .recalc_rate = hi655x_clk_recalc_rate, 80 }; 81 82 static int hi655x_clk_probe(struct platform_device *pdev) 83 { 84 struct device *parent = pdev->dev.parent; 85 struct hi655x_pmic *hi655x = dev_get_drvdata(parent); 86 struct hi655x_clk *hi655x_clk; 87 const char *clk_name = "hi655x-clk"; 88 struct clk_init_data init = { 89 .name = clk_name, 90 .ops = &hi655x_clk_ops 91 }; 92 int ret; 93 94 hi655x_clk = devm_kzalloc(&pdev->dev, sizeof(*hi655x_clk), GFP_KERNEL); 95 if (!hi655x_clk) 96 return -ENOMEM; 97 98 of_property_read_string_index(parent->of_node, "clock-output-names", 99 0, &clk_name); 100 101 hi655x_clk->clk_hw.init = &init; 102 hi655x_clk->hi655x = hi655x; 103 104 platform_set_drvdata(pdev, hi655x_clk); 105 106 ret = devm_clk_hw_register(&pdev->dev, &hi655x_clk->clk_hw); 107 if (ret) 108 return ret; 109 110 return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, 111 &hi655x_clk->clk_hw); 112 } 113 114 static struct platform_driver hi655x_clk_driver = { 115 .probe = hi655x_clk_probe, 116 .driver = { 117 .name = "hi655x-clk", 118 }, 119 }; 120 121 module_platform_driver(hi655x_clk_driver); 122 123 MODULE_DESCRIPTION("Clk driver for the hi655x series PMICs"); 124 MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@linaro.org>"); 125 MODULE_LICENSE("GPL"); 126 MODULE_ALIAS("platform:hi655x-clk"); 127