drivers/clk/qcom/apcs-msm8916.c

   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 = -ENODEV;
  53
  54         regmap = dev_get_regmap(parent, NULL);
  55         if (!regmap) {
  56                 dev_err(dev, "failed to get regmap: %d\n", ret);
  57                 return ret;
  58         }
  59
  60         a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL);
  61         if (!a53cc)
  62                 return -ENOMEM;
  63
  64         init.name = "a53mux";
  65         init.parent_names = gpll0_a53cc;
  66         init.num_parents = ARRAY_SIZE(gpll0_a53cc);
  67         init.ops = &clk_regmap_mux_div_ops;
  68         init.flags = CLK_SET_RATE_PARENT;
  69
  70         a53cc->clkr.hw.init = &init;
  71         a53cc->clkr.regmap = regmap;
  72         a53cc->reg_offset = 0x50;
  73         a53cc->hid_width = 5;
  74         a53cc->hid_shift = 0;
  75         a53cc->src_width = 3;
  76         a53cc->src_shift = 8;
  77         a53cc->parent_map = gpll0_a53cc_map;
  78
  79         a53cc->pclk = devm_clk_get(parent, NULL);
  80         if (IS_ERR(a53cc->pclk)) {
  81                 ret = PTR_ERR(a53cc->pclk);
  82                 dev_err(dev, "failed to get clk: %d\n", ret);
  83                 return ret;
  84         }
  85
  86         a53cc->clk_nb.notifier_call = a53cc_notifier_cb;
  87         ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb);
  88         if (ret) {
  89                 dev_err(dev, "failed to register clock notifier: %d\n", ret);
  90                 return ret;
  91         }
  92
  93         ret = devm_clk_register_regmap(dev, &a53cc->clkr);
  94         if (ret) {
  95                 dev_err(dev, "failed to register regmap clock: %d\n", ret);
  96                 goto err;
  97         }
  98
  99         ret = of_clk_add_hw_provider(parent->of_node, of_clk_hw_simple_get,
 100                                      &a53cc->clkr.hw);
 101         if (ret) {
 102                 dev_err(dev, "failed to add clock provider: %d\n", ret);
 103                 goto err;
 104         }
 105
 106         platform_set_drvdata(pdev, a53cc);
 107
 108         return 0;
 109
 110 err:
 111         clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
 112         return ret;
 113 }
 114
 115 static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev)
 116 {
 117         struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev);
 118         struct device *parent = pdev->dev.parent;
 119
 120         clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb);
 121         of_clk_del_provider(parent->of_node);
 122
 123         return 0;
 124 }
 125
 126 static struct platform_driver qcom_apcs_msm8916_clk_driver = {
 127         .probe = qcom_apcs_msm8916_clk_probe,
 128         .remove = qcom_apcs_msm8916_clk_remove,
 129         .driver = {
 130                 .name = "qcom-apcs-msm8916-clk",
 131         },
 132 };
 133 module_platform_driver(qcom_apcs_msm8916_clk_driver);
 134
 135 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
 136 MODULE_LICENSE("GPL v2");
 137 MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver");