arch/arm/mach-msm/gpiomux.c

   1 /* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  15  * 02110-1301, USA.
  16  */
  17 #include <linux/module.h>
  18 #include <linux/spinlock.h>
  19 #include "gpiomux.h"
  20 #include "proc_comm.h"
  21
  22 static DEFINE_SPINLOCK(gpiomux_lock);
  23
  24 static void __msm_gpiomux_write(unsigned gpio, gpiomux_config_t val)
  25 {
  26         unsigned tlmm_config  = (val & ~GPIOMUX_CTL_MASK) |
  27                                 ((gpio & 0x3ff) << 4);
  28         unsigned tlmm_disable = 0;
  29         int rc;
  30
  31         rc = msm_proc_comm(PCOM_RPC_GPIO_TLMM_CONFIG_EX,
  32                            &tlmm_config, &tlmm_disable);
  33         if (rc)
  34                 pr_err("%s: unexpected proc_comm failure %d: %08x %08x\n",
  35                        __func__, rc, tlmm_config, tlmm_disable);
  36 }
  37
  38 int msm_gpiomux_write(unsigned gpio,
  39                       gpiomux_config_t active,
  40                       gpiomux_config_t suspended)
  41 {
  42         struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio;
  43         unsigned long irq_flags;
  44         gpiomux_config_t setting;
  45
  46         if (gpio >= GPIOMUX_NGPIOS)
  47                 return -EINVAL;
  48
  49         spin_lock_irqsave(&gpiomux_lock, irq_flags);
  50
  51         if (active & GPIOMUX_VALID)
  52                 cfg->active = active;
  53
  54         if (suspended & GPIOMUX_VALID)
  55                 cfg->suspended = suspended;
  56
  57         setting = cfg->ref ? active : suspended;
  58         if (setting & GPIOMUX_VALID)
  59                 __msm_gpiomux_write(gpio, setting);
  60
  61         spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
  62         return 0;
  63 }
  64 EXPORT_SYMBOL(msm_gpiomux_write);
  65
  66 int msm_gpiomux_get(unsigned gpio)
  67 {
  68         struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio;
  69         unsigned long irq_flags;
  70
  71         if (gpio >= GPIOMUX_NGPIOS)
  72                 return -EINVAL;
  73
  74         spin_lock_irqsave(&gpiomux_lock, irq_flags);
  75         if (cfg->ref++ == 0 && cfg->active & GPIOMUX_VALID)
  76                 __msm_gpiomux_write(gpio, cfg->active);
  77         spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
  78         return 0;
  79 }
  80 EXPORT_SYMBOL(msm_gpiomux_get);
  81
  82 int msm_gpiomux_put(unsigned gpio)
  83 {
  84         struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio;
  85         unsigned long irq_flags;
  86
  87         if (gpio >= GPIOMUX_NGPIOS)
  88                 return -EINVAL;
  89
  90         spin_lock_irqsave(&gpiomux_lock, irq_flags);
  91         BUG_ON(cfg->ref == 0);
  92         if (--cfg->ref == 0 && cfg->suspended & GPIOMUX_VALID)
  93                 __msm_gpiomux_write(gpio, cfg->suspended);
  94         spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
  95         return 0;
  96 }
  97 EXPORT_SYMBOL(msm_gpiomux_put);
  98
  99 static int __init gpiomux_init(void)
 100 {
 101         unsigned n;
 102
 103         for (n = 0; n < GPIOMUX_NGPIOS; ++n) {
 104                 msm_gpiomux_configs[n].ref = 0;
 105                 if (!(msm_gpiomux_configs[n].suspended & GPIOMUX_VALID))
 106                         continue;
 107                 __msm_gpiomux_write(n, msm_gpiomux_configs[n].suspended);
 108         }
 109         return 0;
 110 }
 111 postcore_initcall(gpiomux_init);