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

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Marvell Armada 37xx SoC xtal clocks
0004  *
0005  * Copyright (C) 2016 Marvell
0006  *
0007  * Gregory CLEMENT <gregory.clement@free-electrons.com>
0008  *
0009  */
0010
0011 #include <linux/clk-provider.h>
0012 #include <linux/mfd/syscon.h>
0013 #include <linux/platform_device.h>
0014 #include <linux/regmap.h>
0015
0016 #define NB_GPIO1_LATCH  0x8
0017 #define XTAL_MODE       BIT(9)
0018
0019 static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
0020 {
0021     struct device_node *np = pdev->dev.of_node;
0022     const char *xtal_name = "xtal";
0023     struct device_node *parent;
0024     struct regmap *regmap;
0025     struct clk_hw *xtal_hw;
0026     unsigned int rate;
0027     u32 reg;
0028     int ret;
0029
0030     xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
0031     if (!xtal_hw)
0032         return -ENOMEM;
0033
0034     platform_set_drvdata(pdev, xtal_hw);
0035
0036     parent = np->parent;
0037     if (!parent) {
0038         dev_err(&pdev->dev, "no parent\n");
0039         return -ENODEV;
0040     }
0041
0042     regmap = syscon_node_to_regmap(parent);
0043     if (IS_ERR(regmap)) {
0044         dev_err(&pdev->dev, "cannot get regmap\n");
0045         return PTR_ERR(regmap);
0046     }
0047
0048     ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
0049     if (ret) {
0050         dev_err(&pdev->dev, "cannot read from regmap\n");
0051         return ret;
0052     }
0053
0054     if (reg & XTAL_MODE)
0055         rate = 40000000;
0056     else
0057         rate = 25000000;
0058
0059     of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
0060     xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
0061     if (IS_ERR(xtal_hw))
0062         return PTR_ERR(xtal_hw);
0063     ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
0064
0065     return ret;
0066 }
0067
0068 static int armada_3700_xtal_clock_remove(struct platform_device *pdev)
0069 {
0070     of_clk_del_provider(pdev->dev.of_node);
0071
0072     return 0;
0073 }
0074
0075 static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
0076     { .compatible = "marvell,armada-3700-xtal-clock", },
0077     { }
0078 };
0079
0080 static struct platform_driver armada_3700_xtal_clock_driver = {
0081     .probe = armada_3700_xtal_clock_probe,
0082     .remove = armada_3700_xtal_clock_remove,
0083     .driver     = {
0084         .name   = "marvell-armada-3700-xtal-clock",
0085         .of_match_table = armada_3700_xtal_clock_of_match,
0086     },
0087 };
0088
0089 builtin_platform_driver(armada_3700_xtal_clock_driver);