LXR linux/drivers/soc/lantiq/fpi-bus.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 *  Copyright (C) 2011-2015 John Crispin <blogic@phrozen.org>
   5 *  Copyright (C) 2015 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
   6 *  Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>
   7 */
   8
   9#include <linux/device.h>
  10#include <linux/err.h>
  11#include <linux/mfd/syscon.h>
  12#include <linux/module.h>
  13#include <linux/of.h>
  14#include <linux/of_platform.h>
  15#include <linux/platform_device.h>
  16#include <linux/property.h>
  17#include <linux/regmap.h>
  18
  19#include <lantiq_soc.h>
  20
  21#define XBAR_ALWAYS_LAST        0x430
  22#define XBAR_FPI_BURST_EN       BIT(1)
  23#define XBAR_AHB_BURST_EN       BIT(2)
  24
  25#define RCU_VR9_BE_AHB1S        0x00000008
  26
  27static int ltq_fpi_probe(struct platform_device *pdev)
  28{
  29        struct device *dev = &pdev->dev;
  30        struct device_node *np = dev->of_node;
  31        struct resource *res_xbar;
  32        struct regmap *rcu_regmap;
  33        void __iomem *xbar_membase;
  34        u32 rcu_ahb_endianness_reg_offset;
  35        int ret;
  36
  37        res_xbar = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  38        xbar_membase = devm_ioremap_resource(dev, res_xbar);
  39        if (IS_ERR(xbar_membase))
  40                return PTR_ERR(xbar_membase);
  41
  42        /* RCU configuration is optional */
  43        rcu_regmap = syscon_regmap_lookup_by_phandle(np, "lantiq,rcu");
  44        if (IS_ERR(rcu_regmap))
  45                return PTR_ERR(rcu_regmap);
  46
  47        ret = device_property_read_u32(dev, "lantiq,offset-endianness",
  48                                       &rcu_ahb_endianness_reg_offset);
  49        if (ret) {
  50                dev_err(&pdev->dev, "Failed to get RCU reg offset\n");
  51                return ret;
  52        }
  53
  54        ret = regmap_update_bits(rcu_regmap, rcu_ahb_endianness_reg_offset,
  55                                 RCU_VR9_BE_AHB1S, RCU_VR9_BE_AHB1S);
  56        if (ret) {
  57                dev_warn(&pdev->dev,
  58                         "Failed to configure RCU AHB endianness\n");
  59                return ret;
  60        }
  61
  62        /* disable fpi burst */
  63        ltq_w32_mask(XBAR_FPI_BURST_EN, 0, xbar_membase + XBAR_ALWAYS_LAST);
  64
  65        return of_platform_populate(dev->of_node, NULL, NULL, dev);
  66}
  67
  68static const struct of_device_id ltq_fpi_match[] = {
  69        { .compatible = "lantiq,xrx200-fpi" },
  70        {},
  71};
  72MODULE_DEVICE_TABLE(of, ltq_fpi_match);
  73
  74static struct platform_driver ltq_fpi_driver = {
  75        .probe = ltq_fpi_probe,
  76        .driver = {
  77                .name = "fpi-xway",
  78                .of_match_table = ltq_fpi_match,
  79        },
  80};
  81
  82module_platform_driver(ltq_fpi_driver);
  83
  84MODULE_DESCRIPTION("Lantiq FPI bus driver");
  85MODULE_LICENSE("GPL");
  86