arch/arm/plat-rk/efuse.c

   1 /*
   2  * Copyright (C) 2013 ROCKCHIP, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/delay.h>
  10 #include <linux/kernel.h>
  11 #include <linux/io.h>
  12 #include <linux/spinlock.h>
  13 #include <plat/efuse.h>
  14
  15 #if defined(CONFIG_ARCH_RK3188)
  16 #define efuse_readl(offset)             readl_relaxed(RK30_EFUSE_BASE + offset)
  17 #define efuse_writel(val, offset)       writel_relaxed(val, RK30_EFUSE_BASE + offset)
  18 #endif
  19
  20 u8 efuse_buf[32 + 1] = {0, 0};
  21
  22 static int efuse_readregs(u32 addr, u32 length, u8 *buf)
  23 {
  24 #ifndef efuse_readl
  25         return 0;
  26 #else
  27         unsigned long flags;
  28         static DEFINE_SPINLOCK(efuse_lock);
  29         int ret = length;
  30
  31         if (!length)
  32                 return 0;
  33
  34         spin_lock_irqsave(&efuse_lock, flags);
  35
  36         efuse_writel(EFUSE_CSB, REG_EFUSE_CTRL);
  37         efuse_writel(EFUSE_LOAD | EFUSE_PGENB, REG_EFUSE_CTRL);
  38         udelay(2);
  39         do {
  40                 efuse_writel(efuse_readl(REG_EFUSE_CTRL) & (~(EFUSE_A_MASK << EFUSE_A_SHIFT)), REG_EFUSE_CTRL);
  41                 efuse_writel(efuse_readl(REG_EFUSE_CTRL) | ((addr & EFUSE_A_MASK) << EFUSE_A_SHIFT), REG_EFUSE_CTRL);
  42                 udelay(2);
  43                 efuse_writel(efuse_readl(REG_EFUSE_CTRL) | EFUSE_STROBE, REG_EFUSE_CTRL);
  44                 udelay(2);
  45                 *buf = efuse_readl(REG_EFUSE_DOUT);
  46                 efuse_writel(efuse_readl(REG_EFUSE_CTRL) & (~EFUSE_STROBE), REG_EFUSE_CTRL);
  47                 udelay(2);
  48                 buf++;
  49                 addr++;
  50         } while(--length);
  51         udelay(2);
  52         efuse_writel(efuse_readl(REG_EFUSE_CTRL) | EFUSE_CSB, REG_EFUSE_CTRL);
  53         udelay(1);
  54
  55         spin_unlock_irqrestore(&efuse_lock, flags);
  56         return ret;
  57 #endif
  58 }
  59
  60 void rk_efuse_init(void)
  61 {
  62         efuse_readregs(0x0, 32, efuse_buf);
  63 }
  64
  65 int rk_pll_flag(void)
  66 {
  67         return efuse_buf[22] & 0x3;
  68 }
  69
  70 int rk_leakage_val(void)
  71 {
  72         return (efuse_buf[22] >> 4) & 0x0f;
  73 }