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
  30 struct 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 }