1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Clock driver for Hi655x 4 * 5 * Copyright (c) 2017, Linaro Ltd. 6 * 7 * Author: Daniel Lezcano <daniel.lezcano@linaro.org> 8 */ 9 #include <linux/clk-provider.h> 10 #include <linux/module.h> 11 #include <linux/platform_device.h> 12 #include <linux/regmap.h> 13 #include <linux/slab.h> 14 #include <linux/mfd/core.h> 15 #include <linux/mfd/hi655x-pmic.h> 16 17 #define HI655X_CLK_BASE HI655X_BUS_ADDR(0x1c) 18 #define HI655X_CLK_SET BIT(6) 19 20 struct hi655x_clk { 21 struct hi655x_pmic *hi655x; 22 struct clk_hw clk_hw; 23 }; 24 25 static unsigned long hi655x_clk_recalc_rate(struct clk_hw *hw, 26 unsigned long parent_rate) 27 { 28 return 32768; 29 } 30 31 static int hi655x_clk_enable(struct clk_hw *hw, bool enable) 32 { 33 struct hi655x_clk *hi655x_clk = 34 container_of(hw, struct hi655x_clk, clk_hw); 35 36 struct hi655x_pmic *hi655x = hi655x_clk->hi655x; 37 38 return regmap_update_bits(hi655x->regmap, HI655X_CLK_BASE, 39 HI655X_CLK_SET, enable ? HI655X_CLK_SET : 0); 40 } 41 42 static int hi655x_clk_prepare(struct clk_hw *hw) 43 { 44 return hi655x_clk_enable(hw, true); 45 } 46 47 static void hi655x_clk_unprepare(struct clk_hw *hw) 48 { 49 hi655x_clk_enable(hw, false); 50 } 51 52 static int hi655x_clk_is_prepared(struct clk_hw *hw) 53 { 54 struct hi655x_clk *hi655x_clk = 55 container_of(hw, struct hi655x_clk, clk_hw); 56 struct hi655x_pmic *hi655x = hi655x_clk->hi655x; 57 int ret; 58 uint32_t val; 59 60 ret = regmap_read(hi655x->regmap, HI655X_CLK_BASE, &val); 61 if (ret < 0) 62 return ret; 63 64 return val & HI655X_CLK_BASE; 65 } 66 67 static const struct clk_ops hi655x_clk_ops = { 68 .prepare = hi655x_clk_prepare, 69 .unprepare = hi655x_clk_unprepare, 70 .is_prepared = hi655x_clk_is_prepared, 71 .recalc_rate = hi655x_clk_recalc_rate, 72 }; 73 74 static int hi655x_clk_probe(struct platform_device *pdev) 75 { 76 struct device *parent = pdev->dev.parent; 77 struct hi655x_pmic *hi655x = dev_get_drvdata(parent); 78 struct hi655x_clk *hi655x_clk; 79 const char *clk_name = "hi655x-clk"; 80 struct clk_init_data init = { 81 .name = clk_name, 82 .ops = &hi655x_clk_ops 83 }; 84 int ret; 85 86 hi655x_clk = devm_kzalloc(&pdev->dev, sizeof(*hi655x_clk), GFP_KERNEL); 87 if (!hi655x_clk) 88 return -ENOMEM; 89 90 of_property_read_string_index(parent->of_node, "clock-output-names", 91 0, &clk_name); 92 93 hi655x_clk->clk_hw.init = &init; 94 hi655x_clk->hi655x = hi655x; 95 96 platform_set_drvdata(pdev, hi655x_clk); 97 98 ret = devm_clk_hw_register(&pdev->dev, &hi655x_clk->clk_hw); 99 if (ret) 100 return ret; 101 102 return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, 103 &hi655x_clk->clk_hw); 104 } 105 106 static struct platform_driver hi655x_clk_driver = { 107 .probe = hi655x_clk_probe, 108 .driver = { 109 .name = "hi655x-clk", 110 }, 111 }; 112 113 module_platform_driver(hi655x_clk_driver); 114 115 MODULE_DESCRIPTION("Clk driver for the hi655x series PMICs"); 116 MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@linaro.org>"); 117 MODULE_LICENSE("GPL"); 118 MODULE_ALIAS("platform:hi655x-clk"); 119