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
  23 #if defined(CONFIG_MSM_V2_TLMM)
  24 #include "gpiomux-v2.h"
  25 #else
  26 #include "gpiomux-v1.h"
  27 #endif
  28
  29 /**
  30  * struct msm_gpiomux_config: gpiomux settings for one gpio line.
  31  *
  32  * A complete gpiomux config is the bitwise-or of a drive-strength,
  33  * function, and pull.  For functions other than GPIO, the OE
  34  * is hard-wired according to the function.  For GPIO mode,
  35  * OE is controlled by gpiolib.
  36  *
  37  * Available settings differ by target; see the gpiomux header
  38  * specific to your target arch for available configurations.
  39  *
  40  * @active: The configuration to be installed when the line is
  41  * active, or its reference count is > 0.
  42  * @suspended: The configuration to be installed when the line
  43  * is suspended, or its reference count is 0.
  44  * @ref: The reference count of the line.  For internal use of
  45  * the gpiomux framework only.
  46  */
  47 struct msm_gpiomux_config {
  48         gpiomux_config_t active;
  49         gpiomux_config_t suspended;
  50         unsigned         ref;
  51 };
  52
  53 /**
  54  * @GPIOMUX_VALID:      If set, the config field contains 'good data'.
  55  *                      The absence of this bit will prevent the gpiomux
  56  *                      system from applying the configuration under all
  57  *                      circumstances.
  58  */
  59 enum {
  60         GPIOMUX_VALID    = BIT(sizeof(gpiomux_config_t) * BITS_PER_BYTE - 1),
  61         GPIOMUX_CTL_MASK = GPIOMUX_VALID,
  62 };
  63
  64 #ifdef CONFIG_MSM_GPIOMUX
  65
  66 /* Each architecture must provide its own instance of this table.
  67  * To avoid having gpiomux manage any given gpio, one or both of
  68  * the entries can avoid setting GPIOMUX_VALID - the absence
  69  * of that flag will prevent the configuration from being applied
  70  * during state transitions.
  71  */
  72 extern struct msm_gpiomux_config msm_gpiomux_configs[GPIOMUX_NGPIOS];
  73
  74 /* Increment a gpio's reference count, possibly activating the line. */
  75 int __must_check msm_gpiomux_get(unsigned gpio);
  76
  77 /* Decrement a gpio's reference count, possibly suspending the line. */
  78 int msm_gpiomux_put(unsigned gpio);
  79
  80 /* Install a new configuration to the gpio line.  To avoid overwriting
  81  * a configuration, leave the VALID bit out.
  82  */
  83 int msm_gpiomux_write(unsigned gpio,
  84                       gpiomux_config_t active,
  85                       gpiomux_config_t suspended);
  86
  87 /* Architecture-internal function for use by the framework only.
  88  * This function can assume the following:
  89  * - the gpio value has passed a bounds-check
  90  * - the gpiomux spinlock has been obtained
  91  *
  92  * This function is not for public consumption.  External users
  93  * should use msm_gpiomux_write.
  94  */
  95 void __msm_gpiomux_write(unsigned gpio, gpiomux_config_t val);
  96 #else
  97 static inline int __must_check msm_gpiomux_get(unsigned gpio)
  98 {
  99         return -ENOSYS;
 100 }
 101
 102 static inline int msm_gpiomux_put(unsigned gpio)
 103 {
 104         return -ENOSYS;
 105 }
 106
 107 static inline int msm_gpiomux_write(unsigned gpio,
 108                                     gpiomux_config_t active,
 109                                     gpiomux_config_t suspended)
 110 {
 111         return -ENOSYS;
 112 }
 113 #endif
 114 #endif