arch/powerpc/platforms/52xx/mpc52xx_common.c

   1 /*
   2  *
   3  * Utility functions for the Freescale MPC52xx.
   4  *
   5  * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
   6  *
   7  * This file is licensed under the terms of the GNU General Public License
   8  * version 2. This program is licensed "as is" without any warranty of any
   9  * kind, whether express or implied.
  10  *
  11  */
  12
  13 #undef DEBUG
  14
  15 #include <linux/kernel.h>
  16
  17 #include <asm/io.h>
  18 #include <asm/prom.h>
  19 #include <asm/of_platform.h>
  20 #include <asm/mpc52xx.h>
  21
  22
  23 void __iomem *
  24 mpc52xx_find_and_map(const char *compatible)
  25 {
  26         struct device_node *ofn;
  27         const u32 *regaddr_p;
  28         u64 regaddr64, size64;
  29
  30         ofn = of_find_compatible_node(NULL, NULL, compatible);
  31         if (!ofn)
  32                 return NULL;
  33
  34         regaddr_p = of_get_address(ofn, 0, &size64, NULL);
  35         if (!regaddr_p) {
  36                 of_node_put(ofn);
  37                 return NULL;
  38         }
  39
  40         regaddr64 = of_translate_address(ofn, regaddr_p);
  41
  42         of_node_put(ofn);
  43
  44         return ioremap((u32)regaddr64, (u32)size64);
  45 }
  46
  47
  48 /**
  49  *      mpc52xx_find_ipb_freq - Find the IPB bus frequency for a device
  50  *      @node:  device node
  51  *
  52  *      Returns IPB bus frequency, or 0 if the bus frequency cannot be found.
  53  */
  54 unsigned int
  55 mpc52xx_find_ipb_freq(struct device_node *node)
  56 {
  57         struct device_node *np;
  58         const unsigned int *p_ipb_freq = NULL;
  59
  60         of_node_get(node);
  61         while (node) {
  62                 p_ipb_freq = get_property(node, "bus-frequency", NULL);
  63                 if (p_ipb_freq)
  64                         break;
  65
  66                 np = of_get_parent(node);
  67                 of_node_put(node);
  68                 node = np;
  69         }
  70         if (node)
  71                 of_node_put(node);
  72
  73         return p_ipb_freq ? *p_ipb_freq : 0;
  74 }
  75
  76
  77 void __init
  78 mpc52xx_setup_cpu(void)
  79 {
  80         struct mpc52xx_cdm  __iomem *cdm;
  81         struct mpc52xx_xlb  __iomem *xlb;
  82
  83         /* Map zones */
  84         cdm = mpc52xx_find_and_map("mpc52xx-cdm");
  85         xlb = mpc52xx_find_and_map("mpc52xx-xlb");
  86
  87         if (!cdm || !xlb) {
  88                 printk(KERN_ERR __FILE__ ": "
  89                         "Error while mapping CDM/XLB during mpc52xx_setup_cpu. "
  90                         "Expect some abnormal behavior\n");
  91                 goto unmap_regs;
  92         }
  93
  94         /* Use internal 48 Mhz */
  95         out_8(&cdm->ext_48mhz_en, 0x00);
  96         out_8(&cdm->fd_enable, 0x01);
  97         if (in_be32(&cdm->rstcfg) & 0x40)       /* Assumes 33Mhz clock */
  98                 out_be16(&cdm->fd_counters, 0x0001);
  99         else
 100                 out_be16(&cdm->fd_counters, 0x5555);
 101
 102         /* Configure the XLB Arbiter priorities */
 103         out_be32(&xlb->master_pri_enable, 0xff);
 104         out_be32(&xlb->master_priority, 0x11111111);
 105
 106         /* Disable XLB pipelining */
 107         /* (cfr errate 292. We could do this only just before ATA PIO
 108             transaction and re-enable it afterwards ...) */
 109         out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
 110
 111         /* Unmap zones */
 112 unmap_regs:
 113         if (cdm) iounmap(cdm);
 114         if (xlb) iounmap(xlb);
 115 }
 116
 117 static int __init
 118 mpc52xx_declare_of_platform_devices(void)
 119 {
 120         /* Find every child of the SOC node and add it to of_platform */
 121         return of_platform_bus_probe(NULL, NULL, NULL);
 122 }
 123
 124 device_initcall(mpc52xx_declare_of_platform_devices);