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
  27 static 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 regmap *rcu_regmap;
  32         void __iomem *xbar_membase;
  33         u32 rcu_ahb_endianness_reg_offset;
  34         int ret;
  35
  36         xbar_membase = devm_platform_ioremap_resource(pdev, 0);
  37         if (IS_ERR(xbar_membase))
  38                 return PTR_ERR(xbar_membase);
  39
  40         /* RCU configuration is optional */
  41         rcu_regmap = syscon_regmap_lookup_by_phandle(np, "lantiq,rcu");
  42         if (IS_ERR(rcu_regmap))
  43                 return PTR_ERR(rcu_regmap);
  44
  45         ret = device_property_read_u32(dev, "lantiq,offset-endianness",
  46                                        &rcu_ahb_endianness_reg_offset);
  47         if (ret) {
  48                 dev_err(&pdev->dev, "Failed to get RCU reg offset\n");
  49                 return ret;
  50         }
  51
  52         ret = regmap_update_bits(rcu_regmap, rcu_ahb_endianness_reg_offset,
  53                                  RCU_VR9_BE_AHB1S, RCU_VR9_BE_AHB1S);
  54         if (ret) {
  55                 dev_warn(&pdev->dev,
  56                          "Failed to configure RCU AHB endianness\n");
  57                 return ret;
  58         }
  59
  60         /* disable fpi burst */
  61         ltq_w32_mask(XBAR_FPI_BURST_EN, 0, xbar_membase + XBAR_ALWAYS_LAST);
  62
  63         return of_platform_populate(dev->of_node, NULL, NULL, dev);
  64 }
  65
  66 static const struct of_device_id ltq_fpi_match[] = {
  67         { .compatible = "lantiq,xrx200-fpi" },
  68         {},
  69 };
  70 MODULE_DEVICE_TABLE(of, ltq_fpi_match);
  71
  72 static struct platform_driver ltq_fpi_driver = {
  73         .probe = ltq_fpi_probe,
  74         .driver = {
  75                 .name = "fpi-xway",
  76                 .of_match_table = ltq_fpi_match,
  77         },
  78 };
  79
  80 module_platform_driver(ltq_fpi_driver);
  81
  82 MODULE_DESCRIPTION("Lantiq FPI bus driver");
  83 MODULE_LICENSE("GPL");