/*
 * Copyright (C) 2015  Masahiro Yamada <yamada.masahiro@socionext.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#ifndef __PINCTRL_H
#define __PINCTRL_H

/**
 * struct pinconf_param - pin config parameters
 *
 * @property: property name in DT nodes
 * @param: ID for this config parameter
 * @default_value: default value for this config parameter used in case
 *      no value is specified in DT nodes
 */
struct pinconf_param {
        const char * const property;
        unsigned int param;
        u32 default_value;
};

/**
 * struct pinctrl_ops - pin control operations, to be implemented by
 * pin controller drivers.
 *
 * The @set_state is the only mandatory operation.  You can implement your
 * pinctrl driver with its own @set_state.  In this case, the other callbacks
 * are not required.  Otherwise, generic pinctrl framework is also available;
 * use pinctrl_generic_set_state for @set_state, and implement other operations
 * depending on your necessity.
 *
 * @get_pins_count: return number of selectable named pins available
 *      in this driver.  (necessary to parse "pins" property in DTS)
 * @get_pin_name: return the pin name of the pin selector,
 *      called by the core to figure out which pin it shall do
 *      operations to.  (necessary to parse "pins" property in DTS)
 * @get_groups_count: return number of selectable named groups available
 *      in this driver.  (necessary to parse "groups" property in DTS)
 * @get_group_name: return the group name of the group selector,
 *      called by the core to figure out which pin group it shall do
 *      operations to.  (necessary to parse "groups" property in DTS)
 * @get_functions_count: return number of selectable named functions available
 *      in this driver.  (necessary for pin-muxing)
 * @get_function_name: return the function name of the muxing selector,
 *      called by the core to figure out which mux setting it shall map a
 *      certain device to.  (necessary for pin-muxing)
 * @pinmux_set: enable a certain muxing function with a certain pin.
 *      The @func_selector selects a certain function whereas @pin_selector
 *      selects a certain pin to be used. On simple controllers one of them
 *      may be ignored.  (necessary for pin-muxing against a single pin)
 * @pinmux_group_set: enable a certain muxing function with a certain pin
 *      group.  The @func_selector selects a certain function whereas
 *      @group_selector selects a certain set of pins to be used. On simple
 *      controllers one of them may be ignored.
 *      (necessary for pin-muxing against a pin group)
 * @pinconf_num_params: number of driver-specific parameters to be parsed
 *      from device trees  (necessary for pin-configuration)
 * @pinconf_params: list of driver_specific parameters to be parsed from
 *      device trees  (necessary for pin-configuration)
 * @pinconf_set: configure an individual pin with a given parameter.
 *      (necessary for pin-configuration against a single pin)
 * @pinconf_group_set: configure all pins in a group with a given parameter.
 *      (necessary for pin-configuration against a pin group)
 * @set_state: do pinctrl operations specified by @config, a pseudo device
 *      pointing a config node. (necessary for pinctrl_full)
 * @set_state_simple: do needed pinctrl operations for a peripherl @periph.
 *      (necessary for pinctrl_simple)
 */
struct pinctrl_ops {
        int (*get_pins_count)(struct udevice *dev);
        const char *(*get_pin_name)(struct udevice *dev, unsigned selector);
        int (*get_groups_count)(struct udevice *dev);
        const char *(*get_group_name)(struct udevice *dev, unsigned selector);
        int (*get_functions_count)(struct udevice *dev);
        const char *(*get_function_name)(struct udevice *dev,
                                         unsigned selector);
        int (*pinmux_set)(struct udevice *dev, unsigned pin_selector,
                          unsigned func_selector);
        int (*pinmux_group_set)(struct udevice *dev, unsigned group_selector,
                                unsigned func_selector);
        unsigned int pinconf_num_params;
        const struct pinconf_param *pinconf_params;
        int (*pinconf_set)(struct udevice *dev, unsigned pin_selector,
                           unsigned param, unsigned argument);
        int (*pinconf_group_set)(struct udevice *dev, unsigned group_selector,
                                 unsigned param, unsigned argument);
        int (*set_state)(struct udevice *dev, struct udevice *config);

        /* for pinctrl-simple */
        int (*set_state_simple)(struct udevice *dev, struct udevice *periph);
        /**
         * request() - Request a particular pinctrl function
         *
         * This activates the selected function.
         *
         * @dev:        Device to adjust (UCLASS_PINCTRL)
         * @func:       Function number (driver-specific)
         * @return 0 if OK, -ve on error
         */
        int (*request)(struct udevice *dev, int func, int flags);

        /**
        * get_periph_id() - get the peripheral ID for a device
        *
        * This generally looks at the peripheral's device tree node to work
        * out the peripheral ID. The return value is normally interpreted as
        * enum periph_id. so long as this is defined by the platform (which it
        * should be).
        *
        * @dev:         Pinctrl device to use for decoding
        * @periph:      Device to check
        * @return peripheral ID of @periph, or -ENOENT on error
        */
        int (*get_periph_id)(struct udevice *dev, struct udevice *periph);

        /**
         * get_gpio_mux() - get the mux value for a particular GPIO
         *
         * This allows the raw mux value for a GPIO to be obtained. It is
         * useful for displaying the function being used by that GPIO, such
         * as with the 'gpio' command. This function is internal to the GPIO
         * subsystem and should not be used by generic code. Typically it is
         * used by a GPIO driver with knowledge of the SoC pinctrl setup.
         *
        * @dev:         Pinctrl device to use
        * @banknum:     GPIO bank number
        * @index:       GPIO index within the bank
        * @return mux value (SoC-specific, e.g. 0 for input, 1 for output)
         */
        int (*get_gpio_mux)(struct udevice *dev, int banknum, int index);
};

#define pinctrl_get_ops(dev)    ((struct pinctrl_ops *)(dev)->driver->ops)

/**
 * Generic pin configuration paramters
 *
 * @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
 *      transition from say pull-up to pull-down implies that you disable
 *      pull-up in the process, this setting disables all biasing.
 * @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
 *      mode, also know as "third-state" (tristate) or "high-Z" or "floating".
 *      On output pins this effectively disconnects the pin, which is useful
 *      if for example some other pin is going to drive the signal connected
 *      to it for a while. Pins used for input are usually always high
 *      impedance.
 * @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
 *      weakly drives the last value on a tristate bus, also known as a "bus
 *      holder", "bus keeper" or "repeater". This allows another device on the
 *      bus to change the value by driving the bus high or low and switching to
 *      tristate. The argument is ignored.
 * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
 *      impedance to VDD). If the argument is != 0 pull-up is enabled,
 *      if it is 0, pull-up is total, i.e. the pin is connected to VDD.
 * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
 *      impedance to GROUND). If the argument is != 0 pull-down is enabled,
 *      if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
 * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
 *      on embedded knowledge of the controller hardware, like current mux
 *      function. The pull direction and possibly strength too will normally
 *      be decided completely inside the hardware block and not be readable
 *      from the kernel side.
 *      If the argument is != 0 pull up/down is enabled, if it is 0, the
 *      configuration is ignored. The proper way to disable it is to use
 *      @PIN_CONFIG_BIAS_DISABLE.
 * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
 *      low, this is the most typical case and is typically achieved with two
 *      active transistors on the output. Setting this config will enable
 *      push-pull mode, the argument is ignored.
 * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
 *      collector) which means it is usually wired with other output ports
 *      which are then pulled up with an external resistor. Setting this
 *      config will enable open drain mode, the argument is ignored.
 * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
 *      (open emitter). Setting this config will enable open source mode, the
 *      argument is ignored.
 * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
 *      passed as argument. The argument is in mA.
 * @PIN_CONFIG_INPUT_ENABLE: enable the pin's input.  Note that this does not
 *      affect the pin's ability to drive output.  1 enables input, 0 disables
 *      input.
 * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
 *      If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
 *      schmitt-trigger mode is disabled.
 * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
 *      schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
 *      the threshold value is given on a custom format as argument when
 *      setting pins to this mode.
 * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
 *      which means it will wait for signals to settle when reading inputs. The
 *      argument gives the debounce time in usecs. Setting the
 *      argument to zero turns debouncing off.
 * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
 *      supplies, the argument to this parameter (on a custom format) tells
 *      the driver which alternative power source to use.
 * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
 *      this parameter (on a custom format) tells the driver which alternative
 *      slew rate to use.
 * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
 *      operation, if several modes of operation are supported these can be
 *      passed in the argument on a custom form, else just use argument 1
 *      to indicate low power mode, argument 0 turns low power mode off.
 * @PIN_CONFIG_OUTPUT: this will configure the pin as an output. Use argument
 *      1 to indicate high level, argument 0 to indicate low level. (Please
 *      see Documentation/pinctrl.txt, section "GPIO mode pitfalls" for a
 *      discussion around this parameter.)
 * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
 *      you need to pass in custom configurations to the pin controller, use
 *      PIN_CONFIG_END+1 as the base offset.
 */
#define PIN_CONFIG_BIAS_DISABLE                 0
#define PIN_CONFIG_BIAS_HIGH_IMPEDANCE          1
#define PIN_CONFIG_BIAS_BUS_HOLD                2
#define PIN_CONFIG_BIAS_PULL_UP                 3
#define PIN_CONFIG_BIAS_PULL_DOWN               4
#define PIN_CONFIG_BIAS_PULL_PIN_DEFAULT        5
#define PIN_CONFIG_DRIVE_PUSH_PULL              6
#define PIN_CONFIG_DRIVE_OPEN_DRAIN             7
#define PIN_CONFIG_DRIVE_OPEN_SOURCE            8
#define PIN_CONFIG_DRIVE_STRENGTH               9
#define PIN_CONFIG_INPUT_ENABLE                 10
#define PIN_CONFIG_INPUT_SCHMITT_ENABLE         11
#define PIN_CONFIG_INPUT_SCHMITT                12
#define PIN_CONFIG_INPUT_DEBOUNCE               13
#define PIN_CONFIG_POWER_SOURCE                 14
#define PIN_CONFIG_SLEW_RATE                    15
#define PIN_CONFIG_LOW_POWER_MODE               16
#define PIN_CONFIG_OUTPUT                       17
#define PIN_CONFIG_END                          0x7FFF

#if CONFIG_IS_ENABLED(PINCTRL_GENERIC)
/**
 * pinctrl_generic_set_state() - generic set_state operation
 * Parse the DT node of @config and its children and handle generic properties
 * such as "pins", "groups", "functions", and pin configuration parameters.
 *
 * @pctldev: pinctrl device
 * @config: config device (pseudo device), pointing a config node in DTS
 * @return: 0 on success, or negative error code on failure
 */
int pinctrl_generic_set_state(struct udevice *pctldev, struct udevice *config);
#else
static inline int pinctrl_generic_set_state(struct udevice *pctldev,
                                            struct udevice *config)
{
        return -EINVAL;
}
#endif

#if CONFIG_IS_ENABLED(PINCTRL)
/**
 * pinctrl_select_state() - set a device to a given state
 *
 * @dev: peripheral device
 * @statename: state name, like "default"
 * @return: 0 on success, or negative error code on failure
 */
int pinctrl_select_state(struct udevice *dev, const char *statename);
#else
static inline int pinctrl_select_state(struct udevice *dev,
                                       const char *statename)
{
        return -EINVAL;
}
#endif

/**
 * pinctrl_request() - Request a particular pinctrl function
 *
 * @dev:        Device to check (UCLASS_PINCTRL)
 * @func:       Function number (driver-specific)
 * @flags:      Flags (driver-specific)
 * @return 0 if OK, -ve on error
 */
int pinctrl_request(struct udevice *dev, int func, int flags);

/**
 * pinctrl_request_noflags() - Request a particular pinctrl function
 *
 * This is similar to pinctrl_request() but uses 0 for @flags.
 *
 * @dev:        Device to check (UCLASS_PINCTRL)
 * @func:       Function number (driver-specific)
 * @return 0 if OK, -ve on error
 */
int pinctrl_request_noflags(struct udevice *dev, int func);

/**
 * pinctrl_get_periph_id() - get the peripheral ID for a device
 *
 * This generally looks at the peripheral's device tree node to work out the
 * peripheral ID. The return value is normally interpreted as enum periph_id.
 * so long as this is defined by the platform (which it should be).
 *
 * @dev:        Pinctrl device to use for decoding
 * @periph:     Device to check
 * @return peripheral ID of @periph, or -ENOENT on error
 */
int pinctrl_get_periph_id(struct udevice *dev, struct udevice *periph);

/**
 * pinctrl_decode_pin_config() - decode pin configuration flags
 *
 * This decodes some of the PIN_CONFIG values into flags, with each value
 * being (1 << pin_cfg). This does not support things with values like the
 * slew rate.
 *
 * @blob:       Device tree blob
 * @node:       Node containing the PIN_CONFIG values
 * @return decoded flag value, or -ve on error
 */
int pinctrl_decode_pin_config(const void *blob, int node);

/**
 * pinctrl_get_gpio_mux() - get the mux value for a particular GPIO
 *
 * This allows the raw mux value for a GPIO to be obtained. It is
 * useful for displaying the function being used by that GPIO, such
 * as with the 'gpio' command. This function is internal to the GPIO
 * subsystem and should not be used by generic code. Typically it is
 * used by a GPIO driver with knowledge of the SoC pinctrl setup.
 *
 * @dev:        Pinctrl device to use
 * @banknum:    GPIO bank number
 * @index:      GPIO index within the bank
 * @return mux value (SoC-specific, e.g. 0 for input, 1 for output)
*/
int pinctrl_get_gpio_mux(struct udevice *dev, int banknum, int index);

#endif /* __PINCTRL_H */