arch/arm/mach-mvebu/mvebu-soc-id.c

   1 /*
   2  * ID and revision information for mvebu SoCs
   3  *
   4  * Copyright (C) 2014 Marvell
   5  *
   6  * Gregory CLEMENT <gregory.clement@free-electrons.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2.  This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  *
  12  * All the mvebu SoCs have information related to their variant and
  13  * revision that can be read from the PCI control register. This is
  14  * done before the PCI initialization to avoid any conflict. Once the
  15  * ID and revision are retrieved, the mapping is freed.
  16  */
  17
  18 #define pr_fmt(fmt) "mvebu-soc-id: " fmt
  19
  20 #include <linux/clk.h>
  21 #include <linux/init.h>
  22 #include <linux/io.h>
  23 #include <linux/kernel.h>
  24 #include <linux/of.h>
  25 #include <linux/of_address.h>
  26 #include "mvebu-soc-id.h"
  27
  28 #define PCIE_DEV_ID_OFF         0x0
  29 #define PCIE_DEV_REV_OFF        0x8
  30
  31 #define SOC_ID_MASK         0xFFFF0000
  32 #define SOC_REV_MASK        0xFF
  33
  34 static u32 soc_dev_id;
  35 static u32 soc_rev;
  36 static bool is_id_valid;
  37
  38 static const struct of_device_id mvebu_pcie_of_match_table[] = {
  39         { .compatible = "marvell,armada-xp-pcie", },
  40         { .compatible = "marvell,armada-370-pcie", },
  41         {},
  42 };
  43
  44 int mvebu_get_soc_id(u32 *dev, u32 *rev)
  45 {
  46         if (is_id_valid) {
  47                 *dev = soc_dev_id;
  48                 *rev = soc_rev;
  49                 return 0;
  50         } else
  51                 return -1;
  52 }
  53
  54 static int __init mvebu_soc_id_init(void)
  55 {
  56         struct device_node *np;
  57         int ret = 0;
  58         void __iomem *pci_base;
  59         struct clk *clk;
  60         struct device_node *child;
  61
  62         np = of_find_matching_node(NULL, mvebu_pcie_of_match_table);
  63         if (!np)
  64                 return ret;
  65
  66         /*
  67          * ID and revision are available from any port, so we
  68          * just pick the first one
  69          */
  70         child = of_get_next_child(np, NULL);
  71         if (child == NULL) {
  72                 pr_err("cannot get pci node\n");
  73                 ret = -ENOMEM;
  74                 goto clk_err;
  75         }
  76
  77         clk = of_clk_get_by_name(child, NULL);
  78         if (IS_ERR(clk)) {
  79                 pr_err("cannot get clock\n");
  80                 ret = -ENOMEM;
  81                 goto clk_err;
  82         }
  83
  84         ret = clk_prepare_enable(clk);
  85         if (ret) {
  86                 pr_err("cannot enable clock\n");
  87                 goto clk_err;
  88         }
  89
  90         pci_base = of_iomap(child, 0);
  91         if (IS_ERR(pci_base)) {
  92                 pr_err("cannot map registers\n");
  93                 ret = -ENOMEM;
  94                 goto res_ioremap;
  95         }
  96
  97         /* SoC ID */
  98         soc_dev_id = readl(pci_base + PCIE_DEV_ID_OFF) >> 16;
  99
 100         /* SoC revision */
 101         soc_rev = readl(pci_base + PCIE_DEV_REV_OFF) & SOC_REV_MASK;
 102
 103         is_id_valid = true;
 104
 105         pr_info("MVEBU SoC ID=0x%X, Rev=0x%X\n", soc_dev_id, soc_rev);
 106
 107         iounmap(pci_base);
 108
 109 res_ioremap:
 110         clk_disable_unprepare(clk);
 111
 112 clk_err:
 113         of_node_put(child);
 114         of_node_put(np);
 115
 116         return ret;
 117 }
 118 core_initcall(mvebu_soc_id_init);
 119