arch/arm/mach-msm/gpiomux.h

   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 #ifndef __ARCH_ARM_MACH_MSM_GPIOMUX_H
  18 #define __ARCH_ARM_MACH_MSM_GPIOMUX_H
  19
  20 #include <linux/bitops.h>
  21 #include <linux/errno.h>
  22 #include <mach/msm_gpiomux.h>
  23
  24 #if defined(CONFIG_MSM_V2_TLMM)
  25 #include "gpiomux-v2.h"
  26 #else
  27 #include "gpiomux-v1.h"
  28 #endif
  29
  30 /**
  31  * struct msm_gpiomux_config: gpiomux settings for one gpio line.
  32  *
  33  * A complete gpiomux config is the bitwise-or of a drive-strength,
  34  * function, and pull.  For functions other than GPIO, the OE
  35  * is hard-wired according to the function.  For GPIO mode,
  36  * OE is controlled by gpiolib.
  37  *
  38  * Available settings differ by target; see the gpiomux header
  39  * specific to your target arch for available configurations.
  40  *
  41  * @active: The configuration to be installed when the line is
  42  * active, or its reference count is > 0.
  43  * @suspended: The configuration to be installed when the line
  44  * is suspended, or its reference count is 0.
  45  * @ref: The reference count of the line.  For internal use of
  46  * the gpiomux framework only.
  47  */
  48 struct msm_gpiomux_config {
  49         gpiomux_config_t active;
  50         gpiomux_config_t suspended;
  51         unsigned         ref;
  52 };
  53
  54 /**
  55  * @GPIOMUX_VALID:      If set, the config field contains 'good data'.
  56  *                      The absence of this bit will prevent the gpiomux
  57  *                      system from applying the configuration under all
  58  *                      circumstances.
  59  */
  60 enum {
  61         GPIOMUX_VALID    = BIT(sizeof(gpiomux_config_t) * BITS_PER_BYTE - 1),
  62         GPIOMUX_CTL_MASK = GPIOMUX_VALID,
  63 };
  64
  65 #ifdef CONFIG_MSM_GPIOMUX
  66
  67 /* Each architecture must provide its own instance of this table.
  68  * To avoid having gpiomux manage any given gpio, one or both of
  69  * the entries can avoid setting GPIOMUX_VALID - the absence
  70  * of that flag will prevent the configuration from being applied
  71  * during state transitions.
  72  */
  73 extern struct msm_gpiomux_config msm_gpiomux_configs[GPIOMUX_NGPIOS];
  74
  75 /* Install a new configuration to the gpio line.  To avoid overwriting
  76  * a configuration, leave the VALID bit out.
  77  */
  78 int msm_gpiomux_write(unsigned gpio,
  79                       gpiomux_config_t active,
  80                       gpiomux_config_t suspended);
  81
  82 /* Architecture-internal function for use by the framework only.
  83  * This function can assume the following:
  84  * - the gpio value has passed a bounds-check
  85  * - the gpiomux spinlock has been obtained
  86  *
  87  * This function is not for public consumption.  External users
  88  * should use msm_gpiomux_write.
  89  */
  90 void __msm_gpiomux_write(unsigned gpio, gpiomux_config_t val);
  91 #else
  92 static inline int msm_gpiomux_write(unsigned gpio,
  93                                     gpiomux_config_t active,
  94                                     gpiomux_config_t suspended)
  95 {
  96         return -ENOSYS;
  97 }
  98 #endif
  99 #endif