LXR linux/arch/arm/mach-at91/soc.c

   1/*
   2 * Copyright (C) 2015 Atmel
   3 *
   4 * Alexandre Belloni <alexandre.belloni@free-electrons.com
   5 * Boris Brezillon <boris.brezillon@free-electrons.com
   6 *
   7 * This file is licensed under the terms of the GNU General Public
   8 * License version 2.  This program is licensed "as is" without any
   9 * warranty of any kind, whether express or implied.
  10 *
  11 */
  12
  13#define pr_fmt(fmt)     "AT91: " fmt
  14
  15#include <linux/io.h>
  16#include <linux/of.h>
  17#include <linux/of_address.h>
  18#include <linux/of_platform.h>
  19#include <linux/slab.h>
  20#include <linux/sys_soc.h>
  21
  22#include "soc.h"
  23
  24#define AT91_DBGU_CIDR                  0x40
  25#define AT91_DBGU_CIDR_VERSION(x)       ((x) & 0x1f)
  26#define AT91_DBGU_CIDR_EXT              BIT(31)
  27#define AT91_DBGU_CIDR_MATCH_MASK       0x7fffffe0
  28#define AT91_DBGU_EXID                  0x44
  29
  30struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
  31{
  32        struct soc_device_attribute *soc_dev_attr;
  33        const struct at91_soc *soc;
  34        struct soc_device *soc_dev;
  35        struct device_node *np;
  36        void __iomem *regs;
  37        u32 cidr, exid;
  38
  39        np = of_find_compatible_node(NULL, NULL, "atmel,at91rm9200-dbgu");
  40        if (!np)
  41                np = of_find_compatible_node(NULL, NULL,
  42                                             "atmel,at91sam9260-dbgu");
  43
  44        if (!np) {
  45                pr_warn("Could not find DBGU node");
  46                return NULL;
  47        }
  48
  49        regs = of_iomap(np, 0);
  50        of_node_put(np);
  51
  52        if (!regs) {
  53                pr_warn("Could not map DBGU iomem range");
  54                return NULL;
  55        }
  56
  57        cidr = readl(regs + AT91_DBGU_CIDR);
  58        exid = readl(regs + AT91_DBGU_EXID);
  59
  60        iounmap(regs);
  61
  62        for (soc = socs; soc->name; soc++) {
  63                if (soc->cidr_match != (cidr & AT91_DBGU_CIDR_MATCH_MASK))
  64                        continue;
  65
  66                if (!(cidr & AT91_DBGU_CIDR_EXT) || soc->exid_match == exid)
  67                        break;
  68        }
  69
  70        if (!soc->name) {
  71                pr_warn("Could not find matching SoC description\n");
  72                return NULL;
  73        }
  74
  75        soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
  76        if (!soc_dev_attr)
  77                return NULL;
  78
  79        soc_dev_attr->family = soc->family;
  80        soc_dev_attr->soc_id = soc->name;
  81        soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%X",
  82                                           AT91_DBGU_CIDR_VERSION(cidr));
  83        soc_dev = soc_device_register(soc_dev_attr);
  84        if (IS_ERR(soc_dev)) {
  85                kfree(soc_dev_attr->revision);
  86                kfree(soc_dev_attr);
  87                pr_warn("Could not register SoC device\n");
  88                return NULL;
  89        }
  90
  91        if (soc->family)
  92                pr_info("Detected SoC family: %s\n", soc->family);
  93        pr_info("Detected SoC: %s, revision %X\n", soc->name,
  94                AT91_DBGU_CIDR_VERSION(cidr));
  95
  96        return soc_dev;
  97}
  98