arch/mips/bcm63xx/cs.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/export.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/log2.h>
  14 #include <bcm63xx_cpu.h>
  15 #include <bcm63xx_io.h>
  16 #include <bcm63xx_regs.h>
  17 #include <bcm63xx_cs.h>
  18
  19 static DEFINE_SPINLOCK(bcm63xx_cs_lock);
  20
  21 /*
  22  * check if given chip select exists
  23  */
  24 static int is_valid_cs(unsigned int cs)
  25 {
  26         if (cs > 6)
  27                 return 0;
  28         return 1;
  29 }
  30
  31 /*
  32  * Configure chipselect base address and size (bytes).
  33  * Size must be a power of two between 8k and 256M.
  34  */
  35 int bcm63xx_set_cs_base(unsigned int cs, u32 base, unsigned int size)
  36 {
  37         unsigned long flags;
  38         u32 val;
  39
  40         if (!is_valid_cs(cs))
  41                 return -EINVAL;
  42
  43         /* sanity check on size */
  44         if (size != roundup_pow_of_two(size))
  45                 return -EINVAL;
  46
  47         if (size < 8 * 1024 || size > 256 * 1024 * 1024)
  48                 return -EINVAL;
  49
  50         val = (base & MPI_CSBASE_BASE_MASK);
  51         /* 8k => 0 - 256M => 15 */
  52         val |= (ilog2(size) - ilog2(8 * 1024)) << MPI_CSBASE_SIZE_SHIFT;
  53
  54         spin_lock_irqsave(&bcm63xx_cs_lock, flags);
  55         bcm_mpi_writel(val, MPI_CSBASE_REG(cs));
  56         spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
  57
  58         return 0;
  59 }
  60
  61 EXPORT_SYMBOL(bcm63xx_set_cs_base);
  62
  63 /*
  64  * configure chipselect timing (ns)
  65  */
  66 int bcm63xx_set_cs_timing(unsigned int cs, unsigned int wait,
  67                            unsigned int setup, unsigned int hold)
  68 {
  69         unsigned long flags;
  70         u32 val;
  71
  72         if (!is_valid_cs(cs))
  73                 return -EINVAL;
  74
  75         spin_lock_irqsave(&bcm63xx_cs_lock, flags);
  76         val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
  77         val &= ~(MPI_CSCTL_WAIT_MASK);
  78         val &= ~(MPI_CSCTL_SETUP_MASK);
  79         val &= ~(MPI_CSCTL_HOLD_MASK);
  80         val |= wait << MPI_CSCTL_WAIT_SHIFT;
  81         val |= setup << MPI_CSCTL_SETUP_SHIFT;
  82         val |= hold << MPI_CSCTL_HOLD_SHIFT;
  83         bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
  84         spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
  85
  86         return 0;
  87 }
  88
  89 EXPORT_SYMBOL(bcm63xx_set_cs_timing);
  90
  91 /*
  92  * configure other chipselect parameter (data bus size, ...)
  93  */
  94 int bcm63xx_set_cs_param(unsigned int cs, u32 params)
  95 {
  96         unsigned long flags;
  97         u32 val;
  98
  99         if (!is_valid_cs(cs))
 100                 return -EINVAL;
 101
 102         /* none of this fields apply to pcmcia */
 103         if (cs == MPI_CS_PCMCIA_COMMON ||
 104             cs == MPI_CS_PCMCIA_ATTR ||
 105             cs == MPI_CS_PCMCIA_IO)
 106                 return -EINVAL;
 107
 108         spin_lock_irqsave(&bcm63xx_cs_lock, flags);
 109         val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
 110         val &= ~(MPI_CSCTL_DATA16_MASK);
 111         val &= ~(MPI_CSCTL_SYNCMODE_MASK);
 112         val &= ~(MPI_CSCTL_TSIZE_MASK);
 113         val &= ~(MPI_CSCTL_ENDIANSWAP_MASK);
 114         val |= params;
 115         bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
 116         spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
 117
 118         return 0;
 119 }
 120
 121 EXPORT_SYMBOL(bcm63xx_set_cs_param);
 122
 123 /*
 124  * set cs status (enable/disable)
 125  */
 126 int bcm63xx_set_cs_status(unsigned int cs, int enable)
 127 {
 128         unsigned long flags;
 129         u32 val;
 130
 131         if (!is_valid_cs(cs))
 132                 return -EINVAL;
 133
 134         spin_lock_irqsave(&bcm63xx_cs_lock, flags);
 135         val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
 136         if (enable)
 137                 val |= MPI_CSCTL_ENABLE_MASK;
 138         else
 139                 val &= ~MPI_CSCTL_ENABLE_MASK;
 140         bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
 141         spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
 142         return 0;
 143 }
 144
 145 EXPORT_SYMBOL(bcm63xx_set_cs_status);