arch/arm/plat-orion/mpp.c

   1 /*
   2  * arch/arm/plat-orion/mpp.c
   3  *
   4  * MPP functions for Marvell orion SoCs
   5  *
   6  * This file is licensed under the terms of the GNU General Public
   7  * License version 2.  This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/mbus.h>
  14 #include <linux/io.h>
  15 #include <linux/gpio.h>
  16 #include <mach/hardware.h>
  17 #include <plat/mpp.h>
  18
  19 /* Address of the ith MPP control register */
  20 static __init unsigned long mpp_ctrl_addr(unsigned int i,
  21                                           unsigned long dev_bus)
  22 {
  23         return dev_bus + (i) * 4;
  24 }
  25
  26
  27 void __init orion_mpp_conf(unsigned int *mpp_list, unsigned int variant_mask,
  28                            unsigned int mpp_max, unsigned int dev_bus)
  29 {
  30         unsigned int mpp_nr_regs = (1 + mpp_max/8);
  31         u32 mpp_ctrl[mpp_nr_regs];
  32         int i;
  33
  34         printk(KERN_DEBUG "initial MPP regs:");
  35         for (i = 0; i < mpp_nr_regs; i++) {
  36                 mpp_ctrl[i] = readl(mpp_ctrl_addr(i, dev_bus));
  37                 printk(" %08x", mpp_ctrl[i]);
  38         }
  39         printk("\n");
  40
  41         for ( ; *mpp_list; mpp_list++) {
  42                 unsigned int num = MPP_NUM(*mpp_list);
  43                 unsigned int sel = MPP_SEL(*mpp_list);
  44                 int shift, gpio_mode;
  45
  46                 if (num > mpp_max) {
  47                         printk(KERN_ERR "orion_mpp_conf: invalid MPP "
  48                                         "number (%u)\n", num);
  49                         continue;
  50                 }
  51                 if (variant_mask & !(*mpp_list & variant_mask)) {
  52                         printk(KERN_WARNING
  53                                "orion_mpp_conf: requested MPP%u config "
  54                                "unavailable on this hardware\n", num);
  55                         continue;
  56                 }
  57
  58                 shift = (num & 7) << 2;
  59                 mpp_ctrl[num / 8] &= ~(0xf << shift);
  60                 mpp_ctrl[num / 8] |= sel << shift;
  61
  62                 gpio_mode = 0;
  63                 if (*mpp_list & MPP_INPUT_MASK)
  64                         gpio_mode |= GPIO_INPUT_OK;
  65                 if (*mpp_list & MPP_OUTPUT_MASK)
  66                         gpio_mode |= GPIO_OUTPUT_OK;
  67                 if (sel != 0)
  68                         gpio_mode = 0;
  69                 orion_gpio_set_valid(num, gpio_mode);
  70         }
  71
  72         printk(KERN_DEBUG "  final MPP regs:");
  73         for (i = 0; i < mpp_nr_regs; i++) {
  74                 writel(mpp_ctrl[i], mpp_ctrl_addr(i, dev_bus));
  75                 printk(" %08x", mpp_ctrl[i]);
  76         }
  77         printk("\n");
  78 }