clk/sunxi/clk-sun6i-apb0.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2014 Free Electrons
0004  *
0005  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
0006  *
0007  * Allwinner A31 APB0 clock driver
0008  */
0009
0010 #include <linux/clk-provider.h>
0011 #include <linux/init.h>
0012 #include <linux/of.h>
0013 #include <linux/platform_device.h>
0014
0015 /*
0016  * The APB0 clk has a configurable divisor.
0017  *
0018  * We must use a clk_div_table and not a regular power of 2
0019  * divisor here, because the first 2 values divide the clock
0020  * by 2.
0021  */
0022 static const struct clk_div_table sun6i_a31_apb0_divs[] = {
0023     { .val = 0, .div = 2, },
0024     { .val = 1, .div = 2, },
0025     { .val = 2, .div = 4, },
0026     { .val = 3, .div = 8, },
0027     { /* sentinel */ },
0028 };
0029
0030 static int sun6i_a31_apb0_clk_probe(struct platform_device *pdev)
0031 {
0032     struct device_node *np = pdev->dev.of_node;
0033     const char *clk_name = np->name;
0034     const char *clk_parent;
0035     void __iomem *reg;
0036     struct clk *clk;
0037
0038     reg = devm_platform_ioremap_resource(pdev, 0);
0039     if (IS_ERR(reg))
0040         return PTR_ERR(reg);
0041
0042     clk_parent = of_clk_get_parent_name(np, 0);
0043     if (!clk_parent)
0044         return -EINVAL;
0045
0046     of_property_read_string(np, "clock-output-names", &clk_name);
0047
0048     clk = clk_register_divider_table(&pdev->dev, clk_name, clk_parent,
0049                      0, reg, 0, 2, 0, sun6i_a31_apb0_divs,
0050                      NULL);
0051     if (IS_ERR(clk))
0052         return PTR_ERR(clk);
0053
0054     return of_clk_add_provider(np, of_clk_src_simple_get, clk);
0055 }
0056
0057 static const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = {
0058     { .compatible = "allwinner,sun6i-a31-apb0-clk" },
0059     { /* sentinel */ }
0060 };
0061
0062 static struct platform_driver sun6i_a31_apb0_clk_driver = {
0063     .driver = {
0064         .name = "sun6i-a31-apb0-clk",
0065         .of_match_table = sun6i_a31_apb0_clk_dt_ids,
0066     },
0067     .probe = sun6i_a31_apb0_clk_probe,
0068 };
0069 builtin_platform_driver(sun6i_a31_apb0_clk_driver);