package/kernel/mt7621-qtn-rgmii/src/mt7621-qtn-rgmii.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2020  Bjørn Mork <bjorn@mork.no>
   4  */
   5 #include <linux/io.h>
   6 #include <linux/module.h>
   7
   8 #define MODULE_NAME "mt7621-qtn-rgmii"
   9 #define RGMII_REG_BASE  0x1e110008
  10 #define RGMII_REG_SIZE  4
  11 #define RGMII_REG_VALUE 0x9000c
  12
  13 static u32 oldval;
  14
  15 static int __init mt7621_qtn_rgmii_init(void)
  16 {
  17         void __iomem *base = ioremap(RGMII_REG_BASE, RGMII_REG_SIZE);
  18
  19         if (!base)
  20                 return -ENOMEM;
  21         oldval = ioread32(base);
  22         if (oldval != RGMII_REG_VALUE) {
  23                 iowrite32(RGMII_REG_VALUE, base);
  24                 pr_info(MODULE_NAME ": changed register 0x%08x value from 0x%08x to 0x%08x\n", RGMII_REG_BASE, oldval,  RGMII_REG_VALUE);
  25         }
  26         iounmap(base);
  27         return 0;
  28 }
  29
  30 static void __exit mt7621_qtn_rgmii_exit(void)
  31 {
  32         void __iomem *base = ioremap(RGMII_REG_BASE, RGMII_REG_SIZE);
  33
  34         if (!base)
  35                 return;
  36         if (oldval != RGMII_REG_VALUE) {
  37                 iowrite32(oldval, base);
  38                 pr_info(MODULE_NAME ": reset register 0x%08x back to 0x%08x\n", RGMII_REG_BASE, oldval);
  39         }
  40         iounmap(base);
  41 }
  42
  43 module_init(mt7621_qtn_rgmii_init);
  44 module_exit(mt7621_qtn_rgmii_exit);
  45
  46 MODULE_LICENSE("GPL");
  47 MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
  48 MODULE_DESCRIPTION("Enable RGMII connected Quantenna module on MT7621");