drivers/clk/mvebu/armada-37xx-xtal.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Marvell Armada 37xx SoC xtal clocks
   4  *
   5  * Copyright (C) 2016 Marvell
   6  *
   7  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   8  *
   9  */
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/mfd/syscon.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regmap.h>
  15
  16 #define NB_GPIO1_LATCH  0x8
  17 #define XTAL_MODE           BIT(9)
  18
  19 static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
  20 {
  21         struct device_node *np = pdev->dev.of_node;
  22         const char *xtal_name = "xtal";
  23         struct device_node *parent;
  24         struct regmap *regmap;
  25         struct clk_hw *xtal_hw;
  26         unsigned int rate;
  27         u32 reg;
  28         int ret;
  29
  30         xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
  31         if (!xtal_hw)
  32                 return -ENOMEM;
  33
  34         platform_set_drvdata(pdev, xtal_hw);
  35
  36         parent = np->parent;
  37         if (!parent) {
  38                 dev_err(&pdev->dev, "no parent\n");
  39                 return -ENODEV;
  40         }
  41
  42         regmap = syscon_node_to_regmap(parent);
  43         if (IS_ERR(regmap)) {
  44                 dev_err(&pdev->dev, "cannot get regmap\n");
  45                 return PTR_ERR(regmap);
  46         }
  47
  48         ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
  49         if (ret) {
  50                 dev_err(&pdev->dev, "cannot read from regmap\n");
  51                 return ret;
  52         }
  53
  54         if (reg & XTAL_MODE)
  55                 rate = 40000000;
  56         else
  57                 rate = 25000000;
  58
  59         of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
  60         xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
  61         if (IS_ERR(xtal_hw))
  62                 return PTR_ERR(xtal_hw);
  63         ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
  64
  65         return ret;
  66 }
  67
  68 static int armada_3700_xtal_clock_remove(struct platform_device *pdev)
  69 {
  70         of_clk_del_provider(pdev->dev.of_node);
  71
  72         return 0;
  73 }
  74
  75 static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
  76         { .compatible = "marvell,armada-3700-xtal-clock", },
  77         { }
  78 };
  79
  80 static struct platform_driver armada_3700_xtal_clock_driver = {
  81         .probe = armada_3700_xtal_clock_probe,
  82         .remove = armada_3700_xtal_clock_remove,
  83         .driver         = {
  84                 .name   = "marvell-armada-3700-xtal-clock",
  85                 .of_match_table = armada_3700_xtal_clock_of_match,
  86         },
  87 };
  88
  89 builtin_platform_driver(armada_3700_xtal_clock_driver);