1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Qualcomm APCS clock controller driver 4 * 5 * Copyright (c) 2017, Linaro Limited 6 * Author: Georgi Djakov <georgi.djakov@linaro.org> 7 */ 8 9 #include <linux/clk.h> 10 #include <linux/clk-provider.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/platform_device.h> 15 #include <linux/regmap.h> 16 17 #include "clk-regmap.h" 18 #include "clk-regmap-mux-div.h" 19 20 static const u32 gpll0_a53cc_map[] = { 4, 5 }; 21 22 static const char * const gpll0_a53cc[] = { 23 "gpll0_vote", 24 "a53pll", 25 }; 26 27 /* 28 * We use the notifier function for switching to a temporary safe configuration 29 * (mux and divider), while the A53 PLL is reconfigured. 30 */ 31 static int a53cc_notifier_cb(struct notifier_block *nb, unsigned long event, 32 void *data) 33 { 34 int ret = 0; 35 struct clk_regmap_mux_div *md = container_of(nb, 36 struct clk_regmap_mux_div, 37 clk_nb); 38 if (event == PRE_RATE_CHANGE) 39 /* set the mux and divider to safe frequency (400mhz) */ 40 ret = mux_div_set_src_div(md, 4, 3); 41 42 return notifier_from_errno(ret); 43 } 44 45 static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev) 46 { 47 struct device *dev = &pdev->dev; 48 struct device *parent = dev->parent; 49 struct clk_regmap_mux_div *a53cc; 50 struct regmap *regmap; 51 struct clk_init_data init = { }; 52 int ret; 53 54 regmap = dev_get_regmap(parent, NULL); 55 if (IS_ERR(regmap)) { 56 ret = PTR_ERR(regmap); 57 dev_err(dev, "failed to get regmap: %d\n", ret); 58 return ret; 59 } 60 61 a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL); 62 if (!a53cc) 63 return -ENOMEM; 64 65 init.name = "a53mux"; 66 init.parent_names = gpll0_a53cc; 67 init.num_parents = ARRAY_SIZE(gpll0_a53cc); 68 init.ops = &clk_regmap_mux_div_ops; 69 init.flags = CLK_SET_RATE_PARENT; 70 71 a53cc->clkr.hw.init = &init; 72 a53cc->clkr.regmap = regmap; 73 a53cc->reg_offset = 0x50; 74 a53cc->hid_width = 5; 75 a53cc->hid_shift = 0; 76 a53cc->src_width = 3; 77 a53cc->src_shift = 8; 78 a53cc->parent_map = gpll0_a53cc_map; 79 80 a53cc->pclk = devm_clk_get(parent, NULL); 81 if (IS_ERR(a53cc->pclk)) { 82 ret = PTR_ERR(a53cc->pclk); 83 dev_err(dev, "failed to get clk: %d\n", ret); 84 return ret; 85 } 86 87 a53cc->clk_nb.notifier_call = a53cc_notifier_cb; 88 ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb); 89 if (ret) { 90 dev_err(dev, "failed to register clock notifier: %d\n", ret); 91 return ret; 92 } 93 94 ret = devm_clk_register_regmap(dev, &a53cc->clkr); 95 if (ret) { 96 dev_err(dev, "failed to register regmap clock: %d\n", ret); 97 goto err; 98 } 99 100 ret = of_clk_add_hw_provider(parent->of_node, of_clk_hw_simple_get, 101 &a53cc->clkr.hw); 102 if (ret) { 103 dev_err(dev, "failed to add clock provider: %d\n", ret); 104 goto err; 105 } 106 107 platform_set_drvdata(pdev, a53cc); 108 109 return 0; 110 111 err: 112 clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb); 113 return ret; 114 } 115 116 static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev) 117 { 118 struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev); 119 struct device *parent = pdev->dev.parent; 120 121 clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb); 122 of_clk_del_provider(parent->of_node); 123 124 return 0; 125 } 126 127 static struct platform_driver qcom_apcs_msm8916_clk_driver = { 128 .probe = qcom_apcs_msm8916_clk_probe, 129 .remove = qcom_apcs_msm8916_clk_remove, 130 .driver = { 131 .name = "qcom-apcs-msm8916-clk", 132 }, 133 }; 134 module_platform_driver(qcom_apcs_msm8916_clk_driver); 135 136 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); 137 MODULE_LICENSE("GPL v2"); 138 MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver"); 139