gpio: idio-16: Introduce the ACCES IDIO-16 GPIO library module (b9b1fc1a) · Commits · jan.koester / Linux

MAINTAINERS

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		@@ -312,6 +312,13 @@ L: linux-iio@vger.kernel.org
		S: Maintained
		F: drivers/counter/104-quad-8.c

		ACCES IDIO-16 GPIO LIBRARY
		M: William Breathitt Gray <william.gray@linaro.org>
		L: linux-gpio@vger.kernel.org
		S: Maintained
		F: drivers/gpio/gpio-idio-16.c
		F: drivers/gpio/gpio-idio-16.h

		ACCES PCI-IDIO-16 GPIO DRIVER
		M: William Breathitt Gray <william.gray@linaro.org>
		L: linux-gpio@vger.kernel.org

drivers/gpio/Kconfig

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		@@ -109,6 +109,15 @@ config GPIO_REGMAP
		config GPIO_MAX730X
		tristate

		config GPIO_IDIO_16
		tristate
		help
		Enables support for the idio-16 library functions. The idio-16 library
		provides functions to facilitate communication with devices within the
		ACCES IDIO-16 family such as the 104-IDIO-16 and the PCI-IDIO-16.

		If built as a module its name will be gpio-idio-16.

		menu "Memory mapped GPIO drivers"
		depends on HAS_IOMEM

drivers/gpio/Makefile

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		@@ -68,6 +68,7 @@ obj-$(CONFIG_GPIO_HLWD) += gpio-hlwd.o
		obj-$(CONFIG_HTC_EGPIO) += gpio-htc-egpio.o
		obj-$(CONFIG_GPIO_I8255) += gpio-i8255.o
		obj-$(CONFIG_GPIO_ICH) += gpio-ich.o
		obj-$(CONFIG_GPIO_IDIO_16) += gpio-idio-16.o
		obj-$(CONFIG_GPIO_IDT3243X) += gpio-idt3243x.o
		obj-$(CONFIG_GPIO_IMX_SCU) += gpio-imx-scu.o
		obj-$(CONFIG_GPIO_IOP) += gpio-iop.o

drivers/gpio/gpio-idio-16.c

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		// SPDX-License-Identifier: GPL-2.0
		/*
		* GPIO library for the ACCES IDIO-16 family
		* Copyright (C) 2022 William Breathitt Gray
		*/
		#include <linux/bitmap.h>
		#include <linux/export.h>
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/spinlock.h>
		#include <linux/types.h>

		#include "gpio-idio-16.h"

		#define DEFAULT_SYMBOL_NAMESPACE GPIO_IDIO_16

		/**
		* idio_16_get - get signal value at signal offset
		* @reg: ACCES IDIO-16 device registers
		* @state: ACCES IDIO-16 device state
		* @offset: offset of signal to get
		*
		* Returns the signal value (0=low, 1=high) for the signal at @offset.
		*/
		int idio_16_get(struct idio_16 __iomem *const reg,
		struct idio_16_state *const state, const unsigned long offset)
		{
		const unsigned long mask = BIT(offset);

		if (offset < IDIO_16_NOUT)
		return test_bit(offset, state->out_state);

		if (offset < 24)
		return !!(ioread8(&reg->in0_7) & (mask >> IDIO_16_NOUT));

		if (offset < 32)
		return !!(ioread8(&reg->in8_15) & (mask >> 24));

		return -EINVAL;
		}
		EXPORT_SYMBOL_GPL(idio_16_get);

		/**
		* idio_16_get_multiple - get multiple signal values at multiple signal offsets
		* @reg: ACCES IDIO-16 device registers
		* @state: ACCES IDIO-16 device state
		* @mask: mask of signals to get
		* @bits: bitmap to store signal values
		*
		* Stores in @bits the values (0=low, 1=high) for the signals defined by @mask.
		*/
		void idio_16_get_multiple(struct idio_16 __iomem *const reg,
		struct idio_16_state *const state,
		const unsigned long *const mask,
		unsigned long *const bits)
		{
		unsigned long flags;
		const unsigned long out_mask = GENMASK(IDIO_16_NOUT - 1, 0);

		spin_lock_irqsave(&state->lock, flags);

		bitmap_replace(bits, bits, state->out_state, &out_mask, IDIO_16_NOUT);
		if (*mask & GENMASK(23, 16))
		bitmap_set_value8(bits, ioread8(&reg->in0_7), 16);
		if (*mask & GENMASK(31, 24))
		bitmap_set_value8(bits, ioread8(&reg->in8_15), 24);

		spin_unlock_irqrestore(&state->lock, flags);
		}
		EXPORT_SYMBOL_GPL(idio_16_get_multiple);

		/**
		* idio_16_set - set signal value at signal offset
		* @reg: ACCES IDIO-16 device registers
		* @state: ACCES IDIO-16 device state
		* @offset: offset of signal to set
		* @value: value of signal to set
		*
		* Assigns output @value for the signal at @offset.
		*/
		void idio_16_set(struct idio_16 __iomem *const reg,
		struct idio_16_state *const state, const unsigned long offset,
		const unsigned long value)
		{
		unsigned long flags;

		if (offset >= IDIO_16_NOUT)
		return;

		spin_lock_irqsave(&state->lock, flags);

		__assign_bit(offset, state->out_state, value);
		if (offset < 8)
		iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
		else
		iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);

		spin_unlock_irqrestore(&state->lock, flags);
		}
		EXPORT_SYMBOL_GPL(idio_16_set);

		/**
		* idio_16_set_multiple - set signal values at multiple signal offsets
		* @reg: ACCES IDIO-16 device registers
		* @state: ACCES IDIO-16 device state
		* @mask: mask of signals to set
		* @bits: bitmap of signal output values
		*
		* Assigns output values defined by @bits for the signals defined by @mask.
		*/
		void idio_16_set_multiple(struct idio_16 __iomem *const reg,
		struct idio_16_state *const state,
		const unsigned long *const mask,
		const unsigned long *const bits)
		{
		unsigned long flags;

		spin_lock_irqsave(&state->lock, flags);

		bitmap_replace(state->out_state, state->out_state, bits, mask,
		IDIO_16_NOUT);
		if (*mask & GENMASK(7, 0))
		iowrite8(bitmap_get_value8(state->out_state, 0), &reg->out0_7);
		if (*mask & GENMASK(15, 8))
		iowrite8(bitmap_get_value8(state->out_state, 8), &reg->out8_15);

		spin_unlock_irqrestore(&state->lock, flags);
		}
		EXPORT_SYMBOL_GPL(idio_16_set_multiple);

		/**
		* idio_16_state_init - initialize idio_16_state structure
		* @state: ACCES IDIO-16 device state
		*
		* Initializes the ACCES IDIO-16 device @state for use in idio-16 library
		* functions.
		*/
		void idio_16_state_init(struct idio_16_state *const state)
		{
		spin_lock_init(&state->lock);
		}
		EXPORT_SYMBOL_GPL(idio_16_state_init);

		MODULE_AUTHOR("William Breathitt Gray");
		MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library");
		MODULE_LICENSE("GPL");

drivers/gpio/gpio-idio-16.h

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		/* SPDX-License-Identifier: GPL-2.0 */
		/* Copyright 2022 William Breathitt Gray */
		#ifndef _IDIO_16_H_
		#define _IDIO_16_H_

		#include <linux/spinlock.h>
		#include <linux/types.h>

		/**
		* struct idio_16 - IDIO-16 registers structure
		* @out0_7: Read: FET Drive Outputs 0-7
		* Write: FET Drive Outputs 0-7
		* @in0_7: Read: Isolated Inputs 0-7
		* Write: Clear Interrupt
		* @irq_ctl: Read: Enable IRQ
		* Write: Disable IRQ
		* @filter_ctl: Read: Activate Input Filters 0-15
		* Write: Deactivate Input Filters 0-15
		* @out8_15: Read: FET Drive Outputs 8-15
		* Write: FET Drive Outputs 8-15
		* @in8_15: Read: Isolated Inputs 8-15
		* Write: Unused
		* @irq_status: Read: Interrupt status
		* Write: Unused
		*/
		struct idio_16 {
		u8 out0_7;
		u8 in0_7;
		u8 irq_ctl;
		u8 filter_ctl;
		u8 out8_15;
		u8 in8_15;
		u8 irq_status;
		};

		#define IDIO_16_NOUT 16

		/**
		* struct idio_16_state - IDIO-16 state structure
		* @lock: synchronization lock for accessing device state
		* @out_state: output signals state
		*/
		struct idio_16_state {
		spinlock_t lock;
		DECLARE_BITMAP(out_state, IDIO_16_NOUT);
		};

		/**
		* idio_16_get_direction - get the I/O direction for a signal offset
		* @offset: offset of signal to get direction
		*
		* Returns the signal direction (0=output, 1=input) for the signal at @offset.
		*/
		static inline int idio_16_get_direction(const unsigned long offset)
		{
		return (offset >= IDIO_16_NOUT) ? 1 : 0;
		}

		int idio_16_get(struct idio_16 __iomem reg, struct idio_16_state state,
		unsigned long offset);
		void idio_16_get_multiple(struct idio_16 __iomem *reg,
		struct idio_16_state *state,
		const unsigned long mask, unsigned long bits);
		void idio_16_set(struct idio_16 __iomem reg, struct idio_16_state state,
		unsigned long offset, unsigned long value);
		void idio_16_set_multiple(struct idio_16 __iomem *reg,
		struct idio_16_state *state,
		const unsigned long mask, const unsigned long bits);
		void idio_16_state_init(struct idio_16_state *state);

		#endif /* _IDIO_16_H_ */