LXR linux/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
  19static 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
  68static 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
  75static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
  76        { .compatible = "marvell,armada-3700-xtal-clock", },
  77        { }
  78};
  79
  80static 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
  89builtin_platform_driver(armada_3700_xtal_clock_driver);
  90