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/*******************************************************************************
* (c) Copyright 2008-2013 Microsemi SoC Products Group. All rights reserved.
*
* SmartFusion2 Microcontroller Subsystem GPIO bare metal software driver public
* API.
*
* SVN $Revision: 5487 $
* SVN $Date: 2013-03-29 15:33:22 +0000 (Fri, 29 Mar 2013) $
*/
/*=========================================================================*//**
@mainpage SmartFusion2 MSS GPIO Bare Metal Driver.
@section intro_sec Introduction
The SmartFusion2 Microcontroller Subsystem (MSS) includes a block of 32 general
purpose input/outputs (GPIO).
This software driver provides a set of functions for controlling the MSS GPIO
block as part of a bare metal system where no operating system is available.
This driver can be adapted for use as part of an operating system but the
implementation of the adaptation layer between this driver and the operating
system's driver model is outside the scope of this driver.
@section hw_dependencies Hardware Flow Dependencies
The configuration of all features of the MSS GPIOs is covered by this driver
with the exception of the SmartFusion2 IOMUX configuration. SmartFusion2
allows multiple non-concurrent uses of some external pins through IOMUX
configuration. This feature allows optimization of external pin usage by
assigning external pins for use by either the microcontroller subsystem or the
FPGA fabric. The MSS GPIOs share SmartFusion2 device external pins with the
FPGA fabric and with other MSS peripherals via an IOMUX. The MSS GPIO ports
can alternatively be routed to the FPGA fabric through an IOMUX.
The IOMUXs are configured using the SmartFusion2 MSS configurator tool. You
must ensure that the MSS GPIOs are enabled and configured in the SmartFusion2
MSS configurator if you wish to use them. For more information on IOMUXs,
refer to the IOMUX section of the SmartFusion2 Microcontroller Subsystem (MSS)
User’s Guide.
The base address, register addresses and interrupt number assignment for the
MSS GPIO block are defined as constants in the SmartFusion2 CMSIS HAL. You
must ensure that the latest SmartFusion2 CMSIS HAL is included in the project
settings of the software tool chain used to build your project and that it is
generated into your project.
@section theory_op Theory of Operation
The MSS GPIO driver functions are grouped into the following categories:
- Initialization
- Configuration
- Reading and setting GPIO state
- Interrupt control
Initialization
The MSS GPIO driver is initialized through a call to the MSS_GPIO_init()
function. The MSS_GPIO_init() function must be called before any other MSS
GPIO driver functions can be called.
Configuration
Each GPIO port is individually configured through a call to the
MSS_GPIO_config() function. Configuration includes deciding if a GPIO port
will be used as an input, an output or both. GPIO ports configured as inputs
can be further configured to generate interrupts based on the input's state.
Interrupts can be level or edge sensitive.
Reading and Setting GPIO State
The state of the GPIO ports can be read and set using the following functions:
- MSS_GPIO_get_inputs()
- MSS_GPIO_get_outputs()
- MSS_GPIO_set_outputs()
- MSS_GPIO_set_output()
- MSS_GPIO_drive_inout()
Interrupt Control
Interrupts generated by GPIO ports configured as inputs are controlled using
the following functions:
- MSS_GPIO_enable_irq()
- MSS_GPIO_disable_irq()
- MSS_GPIO_clear_irq()
*//*=========================================================================*/
#ifndef MSS_GPIO_H_
#define MSS_GPIO_H_
#ifdef __cplusplus
extern "C" {
#endif
#include "../../CMSIS/m2sxxx.h"
/*-------------------------------------------------------------------------*//**
The mss_gpio_id_t enumeration is used to identify individual GPIO ports as an
argument to functions:
- MSS_GPIO_config()
- MSS_GPIO_set_output() and MSS_GPIO_drive_inout()
- MSS_GPIO_enable_irq(), MSS_GPIO_disable_irq() and MSS_GPIO_clear_irq()
*/
typedef enum __mss_gpio_id_t
{
MSS_GPIO_0 = 0,
MSS_GPIO_1 = 1,
MSS_GPIO_2 = 2,
MSS_GPIO_3 = 3,
MSS_GPIO_4 = 4,
MSS_GPIO_5 = 5,
MSS_GPIO_6 = 6,
MSS_GPIO_7 = 7,
MSS_GPIO_8 = 8,
MSS_GPIO_9 = 9,
MSS_GPIO_10 = 10,
MSS_GPIO_11 = 11,
MSS_GPIO_12 = 12,
MSS_GPIO_13 = 13,
MSS_GPIO_14 = 14,
MSS_GPIO_15 = 15,
MSS_GPIO_16 = 16,
MSS_GPIO_17 = 17,
MSS_GPIO_18 = 18,
MSS_GPIO_19 = 19,
MSS_GPIO_20 = 20,
MSS_GPIO_21 = 21,
MSS_GPIO_22 = 22,
MSS_GPIO_23 = 23,
MSS_GPIO_24 = 24,
MSS_GPIO_25 = 25,
MSS_GPIO_26 = 26,
MSS_GPIO_27 = 27,
MSS_GPIO_28 = 28,
MSS_GPIO_29 = 29,
MSS_GPIO_30 = 30,
MSS_GPIO_31 = 31
} mss_gpio_id_t;
/*-------------------------------------------------------------------------*//**
These constant definitions are used as an argument to the
MSS_GPIO_set_outputs() function to identify GPIO ports. A logical OR of these
constants can be used to specify multiple GPIO ports.
These definitions can also be used to identify GPIO ports through logical
operations on the return value of the MSS_GPIO_get_inputs() function.
*/
#define MSS_GPIO_0_MASK 0x00000001uL
#define MSS_GPIO_1_MASK 0x00000002uL
#define MSS_GPIO_2_MASK 0x00000004uL
#define MSS_GPIO_3_MASK 0x00000008uL
#define MSS_GPIO_4_MASK 0x00000010uL
#define MSS_GPIO_5_MASK 0x00000020uL
#define MSS_GPIO_6_MASK 0x00000040uL
#define MSS_GPIO_7_MASK 0x00000080uL
#define MSS_GPIO_8_MASK 0x00000100uL
#define MSS_GPIO_9_MASK 0x00000200uL
#define MSS_GPIO_10_MASK 0x00000400uL
#define MSS_GPIO_11_MASK 0x00000800uL
#define MSS_GPIO_12_MASK 0x00001000uL
#define MSS_GPIO_13_MASK 0x00002000uL
#define MSS_GPIO_14_MASK 0x00004000uL
#define MSS_GPIO_15_MASK 0x00008000uL
#define MSS_GPIO_16_MASK 0x00010000uL
#define MSS_GPIO_17_MASK 0x00020000uL
#define MSS_GPIO_18_MASK 0x00040000uL
#define MSS_GPIO_19_MASK 0x00080000uL
#define MSS_GPIO_20_MASK 0x00100000uL
#define MSS_GPIO_21_MASK 0x00200000uL
#define MSS_GPIO_22_MASK 0x00400000uL
#define MSS_GPIO_23_MASK 0x00800000uL
#define MSS_GPIO_24_MASK 0x01000000uL
#define MSS_GPIO_25_MASK 0x02000000uL
#define MSS_GPIO_26_MASK 0x04000000uL
#define MSS_GPIO_27_MASK 0x08000000uL
#define MSS_GPIO_28_MASK 0x10000000uL
#define MSS_GPIO_29_MASK 0x20000000uL
#define MSS_GPIO_30_MASK 0x40000000uL
#define MSS_GPIO_31_MASK 0x80000000uL
/*-------------------------------------------------------------------------*//**
These constant definitions are used as an argument to the MSS_GPIO_config()
function to specify the I/O mode of each GPIO port.
*/
#define MSS_GPIO_INPUT_MODE 0x0000000002uL
#define MSS_GPIO_OUTPUT_MODE 0x0000000005uL
#define MSS_GPIO_INOUT_MODE 0x0000000003uL
/*-------------------------------------------------------------------------*//**
These constant definitions are used as an argument to the MSS_GPIO_config()
function to specify the interrupt mode of each GPIO port.
*/
#define MSS_GPIO_IRQ_LEVEL_HIGH 0x0000000000uL
#define MSS_GPIO_IRQ_LEVEL_LOW 0x0000000020uL
#define MSS_GPIO_IRQ_EDGE_POSITIVE 0x0000000040uL
#define MSS_GPIO_IRQ_EDGE_NEGATIVE 0x0000000060uL
#define MSS_GPIO_IRQ_EDGE_BOTH 0x0000000080uL
/*-------------------------------------------------------------------------*//**
The mss_gpio_inout_state_t enumeration is used to specify the output state of
an INOUT GPIO port as an argument to the MSS_GPIO_drive_inout() function.
*/
typedef enum mss_gpio_inout_state
{
MSS_GPIO_DRIVE_LOW = 0,
MSS_GPIO_DRIVE_HIGH,
MSS_GPIO_HIGH_Z
} mss_gpio_inout_state_t;
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_init() function initializes the SmartFusion2 MSS GPIO block. It
resets the MSS GPIO hardware block and it also clears any pending MSS GPIO
interrupts in the ARM Cortex-M3 interrupt controller. When the function exits,
it takes the MSS GPIO block out of reset.
@param
This function has no parameters.
@return
This function does not return a value.
*/
void MSS_GPIO_init( void );
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_config() function is used to configure an individual GPIO port.
@param port_id
The port_id parameter identifies the GPIO port to be configured. An
enumeration item of the form MSS_GPIO_n, where n is the number of the GPIO
port, is used to identify the GPIO port. For example, MSS_GPIO_0 identifies
the first GPIO port and MSS_GPIO_31 is the last one.
@param config
The config parameter specifies the configuration to be applied to the GPIO
port identified by the port_id parameter. It is a logical OR of the required
I/O mode and the required interrupt mode. The interrupt mode is not relevant
if the GPIO is configured as an output only.
These I/O mode constants are allowed:
- MSS_GPIO_INPUT_MODE
- MSS_GPIO_OUTPUT_MODE
- MSS_GPIO_INOUT_MODE
These interrupt mode constants are allowed:
- MSS_GPIO_IRQ_LEVEL_HIGH
- MSS_GPIO_IRQ_LEVEL_LOW
- MSS_GPIO_IRQ_EDGE_POSITIVE
- MSS_GPIO_IRQ_EDGE_NEGATIVE
- MSS_GPIO_IRQ_EDGE_BOTH
@return
none.
Example:
The following call will configure GPIO 4 as an input generating interrupts on
a Low to High transition of the input:
@code
MSS_GPIO_config( MSS_GPIO_4, MSS_GPIO_INPUT_MODE | MSS_GPIO_IRQ_EDGE_POSITIVE );
@endcode
*/
void MSS_GPIO_config
(
mss_gpio_id_t port_id,
uint32_t config
);
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_set_outputs() function is used to set the state of all GPIO ports
configured as outputs.
@param value
The value parameter specifies the state of the GPIO ports configured as
outputs. It is a bit mask of the form (MSS_GPIO_n_MASK | MSS_GPIO_m_MASK)
where n and m are numbers identifying GPIOs. For example, (MSS_GPIO_0_MASK |
MSS_GPIO_1_MASK | MSS_GPIO_2_MASK ) specifies that the first, second and
third GPIO outputs must be set High and all other GPIO outputs set Low. The
driver provides 32 mask constants, MSS_GPIO_0_MASK to MSS_GPIO_31_MASK
inclusive, for this purpose.
@return
none.
Example 1:
Set GPIOs outputs 0 and 8 high and all other GPIO outputs low.
@code
MSS_GPIO_set_outputs( MSS_GPIO_0_MASK | MSS_GPIO_8_MASK );
@endcode
Example 2:
Set GPIOs outputs 2 and 4 low without affecting other GPIO outputs.
@code
uint32_t gpio_outputs;
gpio_outputs = MSS_GPIO_get_outputs();
gpio_outputs &= ~( MSS_GPIO_2_MASK | MSS_GPIO_4_MASK );
MSS_GPIO_set_outputs( gpio_outputs );
@endcode
@see MSS_GPIO_get_outputs()
*/
static __INLINE void
MSS_GPIO_set_outputs
(
uint32_t value
)
{
GPIO->GPIO_OUT = value;
}
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_set_output() function is used to set the state of a single GPIO
port configured as an output.
Note: Using bit-band writes might be a better option than this function for
performance critical applications where the application code is not
intended to be ported to a processor other than the ARM Cortex-M3 in
SmartFusion2. The bit-band write equivalent to this function would be:
GPIO_BITBAND->GPIO_OUT[port_id] = (uint32_t)value;
@param port_id
The port_id parameter identifies the GPIO port that is to have its output
set. An enumeration item of the form MSS_GPIO_n, where n is the number of
the GPIO port, is used to identify the GPIO port. For example, MSS_GPIO_0
identifies the first GPIO port and MSS_GPIO_31 is the last one.
@param value
The value parameter specifies the desired state for the GPIO output. A value
of 0 will set the output Low and a value of 1 will set the output High.
@return
This function does not return a value.
Example:
The following call will set GPIO output 12 High, leaving all other GPIO
outputs unaffected:
@code
_GPIO_set_output(MSS_GPIO_12, 1);
@endcode
*/
void MSS_GPIO_set_output
(
mss_gpio_id_t port_id,
uint8_t value
);
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_get_inputs() function is used to read the current state all GPIO
ports configured as inputs.
@return
This function returns a 32-bit unsigned integer where each bit represents
the state of a GPIO input. The least significant bit represents the state of
GPIO input 0 and the most significant bit the state of GPIO input 31.
Example:
Read and assign the current state of the GPIO outputs to a variable.
@code
uint32_t gpio_inputs;
gpio_inputs = MSS_GPIO_get_inputs();
@endcode
*/
static __INLINE uint32_t
MSS_GPIO_get_inputs( void )
{
return GPIO->GPIO_IN;
}
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_get_outputs() function is used to read the current state all GPIO
ports configured as outputs.
@return
This function returns a 32-bit unsigned integer where each bit represents
the state of a GPIO output. The least significant bit represents the state
of GPIO output 0 and the most significant bit the state of GPIO output 31.
Example:
Read and assign the current state of the GPIO outputs to a variable.
@code
uint32_t gpio_outputs;
gpio_outputs = MSS_GPIO_get_outputs();
@endcode
*/
static __INLINE uint32_t
MSS_GPIO_get_outputs( void )
{
return GPIO->GPIO_OUT;
}
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_drive_inout() function is used to set the output state of a
single GPIO port configured as an INOUT. An INOUT GPIO can be in one of three
states:
- High
- Low
- High impedance
An INOUT output would typically be used where several devices can drive the
state of a shared signal line. The High and Low states are equivalent to the
High and Low states of a GPIO configured as an output. The High impedance
state is used to prevent the GPIO from driving its output state onto the
signal line, while at the same time allowing the input state of the GPIO to
be read.
@param port_id
The port_id parameter identifies the GPIO port for which you want to change
the output state. An enumeration item of the form MSS_GPIO_n, where n is the
number of the GPIO port, is used to identify the GPIO port. For example,
MSS_GPIO_0 identifies the first GPIO port and MSS_GPIO_31 is the last one.
@param inout_state
The inout_state parameter specifies the state of the GPIO port identified by
the port_id parameter. Allowed values of type mss_gpio_inout_state_t are as
follows:
- MSS_GPIO_DRIVE_HIGH
- MSS_GPIO_DRIVE_LOW
- MSS_GPIO_HIGH_Z (High impedance)
@return
This function does not return a value.
Example:
The call to MSS_GPIO_drive_inout() below will set the GPIO 7 output to the
high impedance state.
@code
MSS_GPIO_drive_inout( MSS_GPIO_7, MSS_GPIO_HIGH_Z );
@endcode
*/
void MSS_GPIO_drive_inout
(
mss_gpio_id_t port_id,
mss_gpio_inout_state_t inout_state
);
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_enable_irq() function is used to enable interrupt generation for
the specified GPIO input. Interrupts are generated based on the state of the
GPIO input and the interrupt mode configured for it by MSS_GPIO_config().
@param port_id
The port_id parameter identifies the GPIO port for which you want to enable
interrupt generation. An enumeration item of the form MSS_GPIO_n, where n is
the number of the GPIO port, is used to identify the GPIO port. For example,
MSS_GPIO_0 identifies the first GPIO port and MSS_GPIO_31 is the last one.
@return
This function does not return a value.
Example:
The call to MSS_GPIO_enable_irq() below will allow GPIO 8 to generate
interrupts.
@code
MSS_GPIO_enable_irq( MSS_GPIO_8 );
@endcode
*/
void MSS_GPIO_enable_irq
(
mss_gpio_id_t port_id
);
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_disable_irq() function is used to disable interrupt generation
for the specified GPIO input.
@param port_id
The port_id parameter identifies the GPIO port for which you want to disable
interrupt generation. An enumeration item of the form MSS_GPIO_n, where n is
the number of the GPIO port, is used to identify the GPIO port. For example,
MSS_GPIO_0 identifies the first GPIO port and MSS_GPIO_31 is the last one.
@return
This function does not return a value.
Example:
The call to MSS_GPIO_disable_irq() below will prevent GPIO 8 from generating
interrupts.
@code
MSS_GPIO_disable_irq( MSS_GPIO_8 );
@endcode
*/
void MSS_GPIO_disable_irq
(
mss_gpio_id_t port_id
);
/*-------------------------------------------------------------------------*//**
The MSS_GPIO_clear_irq() function is used to clear a pending interrupt from
the specified GPIO input.
Note: The MSS_GPIO_clear_irq() function must be called as part of any GPIO
interrupt service routine (ISR) in order to prevent the same interrupt
event retriggering a call to the GPIO ISR.
@param port_id
The port_id parameter identifies the GPIO port for which you want to clear
the interrupt. An enumeration item of the form MSS_GPIO_n, where n is the
number of the GPIO port, is used to identify the GPIO port. For example,
MSS_GPIO_0 identifies the first GPIO port and MSS_GPIO_31 is the last one.
@return
none.
Example:
The example below demonstrates the use of the MSS_GPIO_clear_irq() function
as part of the GPIO 9 interrupt service routine.
@code
void GPIO9_IRQHandler( void )
{
do_interrupt_processing();
MSS_GPIO_clear_irq( MSS_GPIO_9 );
}
@endcode
*/
void MSS_GPIO_clear_irq
(
mss_gpio_id_t port_id
);
#ifdef __cplusplus
}
#endif
#endif /* MSS_GPIO_H_ */