soc/lantiq/fpi-bus.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  *
0004  *  Copyright (C) 2011-2015 John Crispin <blogic@phrozen.org>
0005  *  Copyright (C) 2015 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
0006  *  Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>
0007  */
0008
0009 #include <linux/device.h>
0010 #include <linux/err.h>
0011 #include <linux/mfd/syscon.h>
0012 #include <linux/module.h>
0013 #include <linux/of.h>
0014 #include <linux/of_platform.h>
0015 #include <linux/platform_device.h>
0016 #include <linux/property.h>
0017 #include <linux/regmap.h>
0018
0019 #include <lantiq_soc.h>
0020
0021 #define XBAR_ALWAYS_LAST    0x430
0022 #define XBAR_FPI_BURST_EN   BIT(1)
0023 #define XBAR_AHB_BURST_EN   BIT(2)
0024
0025 #define RCU_VR9_BE_AHB1S    0x00000008
0026
0027 static int ltq_fpi_probe(struct platform_device *pdev)
0028 {
0029     struct device *dev = &pdev->dev;
0030     struct device_node *np = dev->of_node;
0031     struct regmap *rcu_regmap;
0032     void __iomem *xbar_membase;
0033     u32 rcu_ahb_endianness_reg_offset;
0034     int ret;
0035
0036     xbar_membase = devm_platform_ioremap_resource(pdev, 0);
0037     if (IS_ERR(xbar_membase))
0038         return PTR_ERR(xbar_membase);
0039
0040     /* RCU configuration is optional */
0041     rcu_regmap = syscon_regmap_lookup_by_phandle(np, "lantiq,rcu");
0042     if (IS_ERR(rcu_regmap))
0043         return PTR_ERR(rcu_regmap);
0044
0045     ret = device_property_read_u32(dev, "lantiq,offset-endianness",
0046                        &rcu_ahb_endianness_reg_offset);
0047     if (ret) {
0048         dev_err(&pdev->dev, "Failed to get RCU reg offset\n");
0049         return ret;
0050     }
0051
0052     ret = regmap_update_bits(rcu_regmap, rcu_ahb_endianness_reg_offset,
0053                  RCU_VR9_BE_AHB1S, RCU_VR9_BE_AHB1S);
0054     if (ret) {
0055         dev_warn(&pdev->dev,
0056              "Failed to configure RCU AHB endianness\n");
0057         return ret;
0058     }
0059
0060     /* disable fpi burst */
0061     ltq_w32_mask(XBAR_FPI_BURST_EN, 0, xbar_membase + XBAR_ALWAYS_LAST);
0062
0063     return of_platform_populate(dev->of_node, NULL, NULL, dev);
0064 }
0065
0066 static const struct of_device_id ltq_fpi_match[] = {
0067     { .compatible = "lantiq,xrx200-fpi" },
0068     {},
0069 };
0070 MODULE_DEVICE_TABLE(of, ltq_fpi_match);
0071
0072 static struct platform_driver ltq_fpi_driver = {
0073     .probe = ltq_fpi_probe,
0074     .driver = {
0075         .name = "fpi-xway",
0076         .of_match_table = ltq_fpi_match,
0077     },
0078 };
0079
0080 module_platform_driver(ltq_fpi_driver);
0081
0082 MODULE_DESCRIPTION("Lantiq FPI bus driver");
0083 MODULE_LICENSE("GPL");