arch/arm/plat-samsung/include/plat/gpio-core.h

   1 /* linux/arch/arm/plat-s3c/include/plat/gpio-core.h
   2  *
   3  * Copyright 2008 Simtec Electronics
   4  *      http://armlinux.simtec.co.uk/
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * S3C Platform - GPIO core
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12 */
  13
  14 #ifndef __PLAT_SAMSUNG_GPIO_CORE_H
  15 #define __PLAT_SAMSUNG_GPIO_CORE_H
  16
  17 /* Bring in machine-local definitions, especially S3C_GPIO_END */
  18 #include <mach/gpio-samsung.h>
  19
  20 #define GPIOCON_OFF     (0x00)
  21 #define GPIODAT_OFF     (0x04)
  22
  23 #define con_4bit_shift(__off) ((__off) * 4)
  24
  25 /* Define the core gpiolib support functions that the s3c platforms may
  26  * need to extend or change depending on the hardware and the s3c chip
  27  * selected at build or found at run time.
  28  *
  29  * These definitions are not intended for driver inclusion, there is
  30  * nothing here that should not live outside the platform and core
  31  * specific code.
  32 */
  33
  34 struct samsung_gpio_chip;
  35
  36 /**
  37  * struct samsung_gpio_pm - power management (suspend/resume) information
  38  * @save: Routine to save the state of the GPIO block
  39  * @resume: Routine to resume the GPIO block.
  40  */
  41 struct samsung_gpio_pm {
  42         void (*save)(struct samsung_gpio_chip *chip);
  43         void (*resume)(struct samsung_gpio_chip *chip);
  44 };
  45
  46 struct samsung_gpio_cfg;
  47
  48 /**
  49  * struct samsung_gpio_chip - wrapper for specific implementation of gpio
  50  * @chip: The chip structure to be exported via gpiolib.
  51  * @base: The base pointer to the gpio configuration registers.
  52  * @group: The group register number for gpio interrupt support.
  53  * @irq_base: The base irq number.
  54  * @config: special function and pull-resistor control information.
  55  * @lock: Lock for exclusive access to this gpio bank.
  56  * @pm_save: Save information for suspend/resume support.
  57  * @bitmap_gpio_int: Bitmap for representing GPIO interrupt or not.
  58  *
  59  * This wrapper provides the necessary information for the Samsung
  60  * specific gpios being registered with gpiolib.
  61  *
  62  * The lock protects each gpio bank from multiple access of the shared
  63  * configuration registers, or from reading of data whilst another thread
  64  * is writing to the register set.
  65  *
  66  * Each chip has its own lock to avoid any  contention between different
  67  * CPU cores trying to get one lock for different GPIO banks, where each
  68  * bank of GPIO has its own register space and configuration registers.
  69  */
  70 struct samsung_gpio_chip {
  71         struct gpio_chip        chip;
  72         struct samsung_gpio_cfg *config;
  73         struct samsung_gpio_pm  *pm;
  74         void __iomem            *base;
  75         int                     irq_base;
  76         int                     group;
  77         spinlock_t               lock;
  78 #ifdef CONFIG_PM
  79         u32                     pm_save[4];
  80 #endif
  81         u32                     bitmap_gpio_int;
  82 };
  83
  84 static inline struct samsung_gpio_chip *to_samsung_gpio(struct gpio_chip *gpc)
  85 {
  86         return container_of(gpc, struct samsung_gpio_chip, chip);
  87 }
  88
  89 /**
  90  * samsung_gpiolib_to_irq - convert gpio pin to irq number
  91  * @chip: The gpio chip that the pin belongs to.
  92  * @offset: The offset of the pin in the chip.
  93  *
  94  * This helper returns the irq number calculated from the chip->irq_base and
  95  * the provided offset.
  96  */
  97 extern int samsung_gpiolib_to_irq(struct gpio_chip *chip, unsigned int offset);
  98
  99 /* exported for core SoC support to change */
 100 extern struct samsung_gpio_cfg s3c24xx_gpiocfg_default;
 101
 102 #ifdef CONFIG_S3C_GPIO_TRACK
 103 extern struct samsung_gpio_chip *s3c_gpios[S3C_GPIO_END];
 104
 105 static inline struct samsung_gpio_chip *samsung_gpiolib_getchip(unsigned int chip)
 106 {
 107         return (chip < S3C_GPIO_END) ? s3c_gpios[chip] : NULL;
 108 }
 109 #else
 110 /* machine specific code should provide samsung_gpiolib_getchip */
 111
 112 extern struct samsung_gpio_chip s3c24xx_gpios[];
 113
 114 static inline struct samsung_gpio_chip *samsung_gpiolib_getchip(unsigned int pin)
 115 {
 116         struct samsung_gpio_chip *chip;
 117
 118         if (pin > S3C_GPIO_END)
 119                 return NULL;
 120
 121         chip = &s3c24xx_gpios[pin/32];
 122         return ((pin - chip->chip.base) < chip->chip.ngpio) ? chip : NULL;
 123 }
 124
 125 static inline void s3c_gpiolib_track(struct samsung_gpio_chip *chip) { }
 126 #endif
 127
 128 #ifdef CONFIG_PM
 129 extern struct samsung_gpio_pm samsung_gpio_pm_1bit;
 130 extern struct samsung_gpio_pm samsung_gpio_pm_2bit;
 131 extern struct samsung_gpio_pm samsung_gpio_pm_4bit;
 132 #define __gpio_pm(x) x
 133 #else
 134 #define samsung_gpio_pm_1bit NULL
 135 #define samsung_gpio_pm_2bit NULL
 136 #define samsung_gpio_pm_4bit NULL
 137 #define __gpio_pm(x) NULL
 138
 139 #endif /* CONFIG_PM */
 140
 141 /* locking wrappers to deal with multiple access to the same gpio bank */
 142 #define samsung_gpio_lock(_oc, _fl) spin_lock_irqsave(&(_oc)->lock, _fl)
 143 #define samsung_gpio_unlock(_oc, _fl) spin_unlock_irqrestore(&(_oc)->lock, _fl)
 144
 145 #endif /* __PLAT_SAMSUNG_GPIO_CORE_H */