LXR linux/drivers/clk/sunxi/clk-sun6i-apb0.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2014 Free Electrons
   4 *
   5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
   6 *
   7 * Allwinner A31 APB0 clock driver
   8 */
   9
  10#include <linux/clk-provider.h>
  11#include <linux/init.h>
  12#include <linux/of.h>
  13#include <linux/platform_device.h>
  14
  15/*
  16 * The APB0 clk has a configurable divisor.
  17 *
  18 * We must use a clk_div_table and not a regular power of 2
  19 * divisor here, because the first 2 values divide the clock
  20 * by 2.
  21 */
  22static const struct clk_div_table sun6i_a31_apb0_divs[] = {
  23        { .val = 0, .div = 2, },
  24        { .val = 1, .div = 2, },
  25        { .val = 2, .div = 4, },
  26        { .val = 3, .div = 8, },
  27        { /* sentinel */ },
  28};
  29
  30static int sun6i_a31_apb0_clk_probe(struct platform_device *pdev)
  31{
  32        struct device_node *np = pdev->dev.of_node;
  33        const char *clk_name = np->name;
  34        const char *clk_parent;
  35        struct resource *r;
  36        void __iomem *reg;
  37        struct clk *clk;
  38
  39        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  40        reg = devm_ioremap_resource(&pdev->dev, r);
  41        if (IS_ERR(reg))
  42                return PTR_ERR(reg);
  43
  44        clk_parent = of_clk_get_parent_name(np, 0);
  45        if (!clk_parent)
  46                return -EINVAL;
  47
  48        of_property_read_string(np, "clock-output-names", &clk_name);
  49
  50        clk = clk_register_divider_table(&pdev->dev, clk_name, clk_parent,
  51                                         0, reg, 0, 2, 0, sun6i_a31_apb0_divs,
  52                                         NULL);
  53        if (IS_ERR(clk))
  54                return PTR_ERR(clk);
  55
  56        return of_clk_add_provider(np, of_clk_src_simple_get, clk);
  57}
  58
  59static const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = {
  60        { .compatible = "allwinner,sun6i-a31-apb0-clk" },
  61        { /* sentinel */ }
  62};
  63
  64static struct platform_driver sun6i_a31_apb0_clk_driver = {
  65        .driver = {
  66                .name = "sun6i-a31-apb0-clk",
  67                .of_match_table = sun6i_a31_apb0_clk_dt_ids,
  68        },
  69        .probe = sun6i_a31_apb0_clk_probe,
  70};
  71builtin_platform_driver(sun6i_a31_apb0_clk_driver);
  72