drivers/clk/clk-fsl-flexspi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Layerscape FlexSPI clock driver
0004  *
0005  * Copyright 2020 Michael Walle <michael@walle.cc>
0006  */
0007
0008 #include <linux/clk-provider.h>
0009 #include <linux/io.h>
0010 #include <linux/module.h>
0011 #include <linux/platform_device.h>
0012
0013 static const struct clk_div_table ls1028a_flexspi_divs[] = {
0014     { .val = 0, .div = 1, },
0015     { .val = 1, .div = 2, },
0016     { .val = 2, .div = 3, },
0017     { .val = 3, .div = 4, },
0018     { .val = 4, .div = 5, },
0019     { .val = 5, .div = 6, },
0020     { .val = 6, .div = 7, },
0021     { .val = 7, .div = 8, },
0022     { .val = 11, .div = 12, },
0023     { .val = 15, .div = 16, },
0024     { .val = 16, .div = 20, },
0025     { .val = 17, .div = 24, },
0026     { .val = 18, .div = 28, },
0027     { .val = 19, .div = 32, },
0028     { .val = 20, .div = 80, },
0029     {}
0030 };
0031
0032 static const struct clk_div_table lx2160a_flexspi_divs[] = {
0033     { .val = 1, .div = 2, },
0034     { .val = 3, .div = 4, },
0035     { .val = 5, .div = 6, },
0036     { .val = 7, .div = 8, },
0037     { .val = 11, .div = 12, },
0038     { .val = 15, .div = 16, },
0039     { .val = 16, .div = 20, },
0040     { .val = 17, .div = 24, },
0041     { .val = 18, .div = 28, },
0042     { .val = 19, .div = 32, },
0043     { .val = 20, .div = 80, },
0044     {}
0045 };
0046
0047 static int fsl_flexspi_clk_probe(struct platform_device *pdev)
0048 {
0049     struct device *dev = &pdev->dev;
0050     struct device_node *np = dev->of_node;
0051     const char *clk_name = np->name;
0052     const char *clk_parent;
0053     struct resource *res;
0054     void __iomem *reg;
0055     struct clk_hw *hw;
0056     const struct clk_div_table *divs;
0057
0058     divs = device_get_match_data(dev);
0059     if (!divs)
0060         return -ENOENT;
0061
0062     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0063     if (!res)
0064         return -ENOENT;
0065
0066     /*
0067      * Can't use devm_ioremap_resource() or devm_of_iomap() because the
0068      * resource might already be taken by the parent device.
0069      */
0070     reg = devm_ioremap(dev, res->start, resource_size(res));
0071     if (!reg)
0072         return -ENOMEM;
0073
0074     clk_parent = of_clk_get_parent_name(np, 0);
0075     if (!clk_parent)
0076         return -EINVAL;
0077
0078     of_property_read_string(np, "clock-output-names", &clk_name);
0079
0080     hw = devm_clk_hw_register_divider_table(dev, clk_name, clk_parent, 0,
0081                         reg, 0, 5, 0, divs, NULL);
0082     if (IS_ERR(hw))
0083         return PTR_ERR(hw);
0084
0085     return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw);
0086 }
0087
0088 static const struct of_device_id fsl_flexspi_clk_dt_ids[] = {
0089     { .compatible = "fsl,ls1028a-flexspi-clk", .data = &ls1028a_flexspi_divs },
0090     { .compatible = "fsl,lx2160a-flexspi-clk", .data = &lx2160a_flexspi_divs },
0091     {}
0092 };
0093 MODULE_DEVICE_TABLE(of, fsl_flexspi_clk_dt_ids);
0094
0095 static struct platform_driver fsl_flexspi_clk_driver = {
0096     .driver = {
0097         .name = "fsl-flexspi-clk",
0098         .of_match_table = fsl_flexspi_clk_dt_ids,
0099     },
0100     .probe = fsl_flexspi_clk_probe,
0101 };
0102 module_platform_driver(fsl_flexspi_clk_driver);
0103
0104 MODULE_DESCRIPTION("FlexSPI clock driver for Layerscape SoCs");
0105 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
0106 MODULE_LICENSE("GPL");