drivers/gpio/gpio-ts5500.c - kernel/msm-4.9 - Gitiles

 /*
  * Digital I/O driver for Technologic Systems TS-5500
  *
  * Copyright (c) 2012 Savoir-faire Linux Inc.
  *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
  *
  * Technologic Systems platforms have pin blocks, exposing several Digital
  * Input/Output lines (DIO). This driver aims to support single pin blocks.
  * In that sense, the support is not limited to the TS-5500 blocks.
  * Actually, the following platforms have DIO support:
  *
  * TS-5500:
  *   Documentation: http://wiki.embeddedarm.com/wiki/TS-5500
  *   Blocks: DIO1, DIO2 and LCD port.
  *
  * TS-5600:
  *   Documentation: http://wiki.embeddedarm.com/wiki/TS-5600
  *   Blocks: LCD port (identical to TS-5500 LCD).
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #include <linux/bitops.h>
 #include <linux/gpio.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/platform_data/gpio-ts5500.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

 /* List of supported Technologic Systems platforms DIO blocks */
 enum ts5500_blocks { TS5500_DIO1, TS5500_DIO2, TS5500_LCD, TS5600_LCD };

 struct ts5500_priv {
 	const struct ts5500_dio *pinout;
 	struct gpio_chip gpio_chip;
 	spinlock_t lock;
 	bool strap;
 	u8 hwirq;
 };

 /*
  * Hex 7D is used to control several blocks (e.g. DIO2 and LCD port).
  * This flag ensures that the region has been requested by this driver.
  */
 static bool hex7d_reserved;

 /*
  * This structure is used to describe capabilities of DIO lines,
  * such as available directions and connected interrupt (if any).
  */
 struct ts5500_dio {
 	const u8 value_addr;
 	const u8 value_mask;
 	const u8 control_addr;
 	const u8 control_mask;
 	const bool no_input;
 	const bool no_output;
 	const u8 irq;
 };

 #define TS5500_DIO_IN_OUT(vaddr, vbit, caddr, cbit)	\
 	{						\
 		.value_addr = vaddr,			\
 		.value_mask = BIT(vbit),		\
 		.control_addr = caddr,			\
 		.control_mask = BIT(cbit),		\
 	}

 #define TS5500_DIO_IN(addr, bit)		\
 	{					\
 		.value_addr = addr,		\
 		.value_mask = BIT(bit),		\
 		.no_output = true,		\
 	}

 #define TS5500_DIO_IN_IRQ(addr, bit, _irq)	\
 	{					\
 		.value_addr = addr,		\
 		.value_mask = BIT(bit),		\
 		.no_output = true,		\
 		.irq = _irq,			\
 	}

 #define TS5500_DIO_OUT(addr, bit)		\
 	{					\
 		.value_addr = addr,		\
 		.value_mask = BIT(bit),		\
 		.no_input = true,		\
 	}

 /*
  * Input/Output DIO lines are programmed in groups of 4. Their values are
  * available through 4 consecutive bits in a value port, whereas the direction
  * of these 4 lines is driven by only 1 bit in a control port.
  */
 #define TS5500_DIO_GROUP(vaddr, vbitfrom, caddr, cbit)		\
 	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 0, caddr, cbit),	\
 	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 1, caddr, cbit),	\
 	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 2, caddr, cbit),	\
 	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 3, caddr, cbit)

 /*
  * TS-5500 DIO1 block
  *
  *  value    control  dir    hw
  *  addr bit addr bit in out irq name     pin offset
  *
  *  0x7b  0  0x7a  0  x   x      DIO1_0   1   0
  *  0x7b  1  0x7a  0  x   x      DIO1_1   3   1
  *  0x7b  2  0x7a  0  x   x      DIO1_2   5   2
  *  0x7b  3  0x7a  0  x   x      DIO1_3   7   3
  *  0x7b  4  0x7a  1  x   x      DIO1_4   9   4
  *  0x7b  5  0x7a  1  x   x      DIO1_5   11  5
  *  0x7b  6  0x7a  1  x   x      DIO1_6   13  6
  *  0x7b  7  0x7a  1  x   x      DIO1_7   15  7
  *  0x7c  0  0x7a  5  x   x      DIO1_8   4   8
  *  0x7c  1  0x7a  5  x   x      DIO1_9   6   9
  *  0x7c  2  0x7a  5  x   x      DIO1_10  8   10
  *  0x7c  3  0x7a  5  x   x      DIO1_11  10  11
  *  0x7c  4           x          DIO1_12  12  12
  *  0x7c  5           x      7   DIO1_13  14  13
  */
 static const struct ts5500_dio ts5500_dio1[] = {
 	TS5500_DIO_GROUP(0x7b, 0, 0x7a, 0),
 	TS5500_DIO_GROUP(0x7b, 4, 0x7a, 1),
 	TS5500_DIO_GROUP(0x7c, 0, 0x7a, 5),
 	TS5500_DIO_IN(0x7c, 4),
 	TS5500_DIO_IN_IRQ(0x7c, 5, 7),
 };

 /*
  * TS-5500 DIO2 block
  *
  *  value    control  dir    hw
  *  addr bit addr bit in out irq name     pin offset
  *
  *  0x7e  0  0x7d  0  x   x      DIO2_0   1   0
  *  0x7e  1  0x7d  0  x   x      DIO2_1   3   1
  *  0x7e  2  0x7d  0  x   x      DIO2_2   5   2
  *  0x7e  3  0x7d  0  x   x      DIO2_3   7   3
  *  0x7e  4  0x7d  1  x   x      DIO2_4   9   4
  *  0x7e  5  0x7d  1  x   x      DIO2_5   11  5
  *  0x7e  6  0x7d  1  x   x      DIO2_6   13  6
  *  0x7e  7  0x7d  1  x   x      DIO2_7   15  7
  *  0x7f  0  0x7d  5  x   x      DIO2_8   4   8
  *  0x7f  1  0x7d  5  x   x      DIO2_9   6   9
  *  0x7f  2  0x7d  5  x   x      DIO2_10  8   10
  *  0x7f  3  0x7d  5  x   x      DIO2_11  10  11
  *  0x7f  4           x      6   DIO2_13  14  12
  */
 static const struct ts5500_dio ts5500_dio2[] = {
 	TS5500_DIO_GROUP(0x7e, 0, 0x7d, 0),
 	TS5500_DIO_GROUP(0x7e, 4, 0x7d, 1),
 	TS5500_DIO_GROUP(0x7f, 0, 0x7d, 5),
 	TS5500_DIO_IN_IRQ(0x7f, 4, 6),
 };

 /*
  * TS-5500 LCD port used as DIO block
  * TS-5600 LCD port is identical
  *
  *  value    control  dir    hw
  *  addr bit addr bit in out irq name    pin offset
  *
  *  0x72  0  0x7d  2  x   x      LCD_0   8   0
  *  0x72  1  0x7d  2  x   x      LCD_1   7   1
  *  0x72  2  0x7d  2  x   x      LCD_2   10  2
  *  0x72  3  0x7d  2  x   x      LCD_3   9   3
  *  0x72  4  0x7d  3  x   x      LCD_4   12  4
  *  0x72  5  0x7d  3  x   x      LCD_5   11  5
  *  0x72  6  0x7d  3  x   x      LCD_6   14  6
  *  0x72  7  0x7d  3  x   x      LCD_7   13  7
  *  0x73  0               x      LCD_EN  5   8
  *  0x73  6           x          LCD_WR  6   9
  *  0x73  7           x      1   LCD_RS  3   10
  */
 static const struct ts5500_dio ts5500_lcd[] = {
 	TS5500_DIO_GROUP(0x72, 0, 0x7d, 2),
 	TS5500_DIO_GROUP(0x72, 4, 0x7d, 3),
 	TS5500_DIO_OUT(0x73, 0),
 	TS5500_DIO_IN(0x73, 6),
 	TS5500_DIO_IN_IRQ(0x73, 7, 1),
 };

 static inline void ts5500_set_mask(u8 mask, u8 addr)
 {
 	u8 val = inb(addr);
 	val |= mask;
 	outb(val, addr);
 }

 static inline void ts5500_clear_mask(u8 mask, u8 addr)
 {
 	u8 val = inb(addr);
 	val &= ~mask;
 	outb(val, addr);
 }

 static int ts5500_gpio_input(struct gpio_chip *chip, unsigned offset)
 {
 	struct ts5500_priv *priv = gpiochip_get_data(chip);
 	const struct ts5500_dio line = priv->pinout[offset];
 	unsigned long flags;

 	if (line.no_input)
 		return -ENXIO;

 	if (line.no_output)
 		return 0;

 	spin_lock_irqsave(&priv->lock, flags);
 	ts5500_clear_mask(line.control_mask, line.control_addr);
 	spin_unlock_irqrestore(&priv->lock, flags);

 	return 0;
 }

 static int ts5500_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
 	struct ts5500_priv *priv = gpiochip_get_data(chip);
 	const struct ts5500_dio line = priv->pinout[offset];

 	return !!(inb(line.value_addr) & line.value_mask);
 }

 static int ts5500_gpio_output(struct gpio_chip *chip, unsigned offset, int val)
 {
 	struct ts5500_priv *priv = gpiochip_get_data(chip);
 	const struct ts5500_dio line = priv->pinout[offset];
 	unsigned long flags;

 	if (line.no_output)
 		return -ENXIO;

 	spin_lock_irqsave(&priv->lock, flags);
 	if (!line.no_input)
 		ts5500_set_mask(line.control_mask, line.control_addr);

 	if (val)
 		ts5500_set_mask(line.value_mask, line.value_addr);
 	else
 		ts5500_clear_mask(line.value_mask, line.value_addr);
 	spin_unlock_irqrestore(&priv->lock, flags);

 	return 0;
 }

 static void ts5500_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 {
 	struct ts5500_priv *priv = gpiochip_get_data(chip);
 	const struct ts5500_dio line = priv->pinout[offset];
 	unsigned long flags;

 	spin_lock_irqsave(&priv->lock, flags);
 	if (val)
 		ts5500_set_mask(line.value_mask, line.value_addr);
 	else
 		ts5500_clear_mask(line.value_mask, line.value_addr);
 	spin_unlock_irqrestore(&priv->lock, flags);
 }

 static int ts5500_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	struct ts5500_priv *priv = gpiochip_get_data(chip);
 	const struct ts5500_dio *block = priv->pinout;
 	const struct ts5500_dio line = block[offset];

 	/* Only one pin is connected to an interrupt */
 	if (line.irq)
 		return line.irq;

 	/* As this pin is input-only, we may strap it to another in/out pin */
 	if (priv->strap)
 		return priv->hwirq;

 	return -ENXIO;
 }

 static int ts5500_enable_irq(struct ts5500_priv *priv)
 {
 	int ret = 0;
 	unsigned long flags;

 	spin_lock_irqsave(&priv->lock, flags);
 	if (priv->hwirq == 7)
 		ts5500_set_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
 	else if (priv->hwirq == 6)
 		ts5500_set_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
 	else if (priv->hwirq == 1)
 		ts5500_set_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
 	else
 		ret = -EINVAL;
 	spin_unlock_irqrestore(&priv->lock, flags);

 	return ret;
 }

 static void ts5500_disable_irq(struct ts5500_priv *priv)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&priv->lock, flags);
 	if (priv->hwirq == 7)
 		ts5500_clear_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
 	else if (priv->hwirq == 6)
 		ts5500_clear_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
 	else if (priv->hwirq == 1)
 		ts5500_clear_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
 	else
 		dev_err(priv->gpio_chip.parent, "invalid hwirq %d\n",
 			priv->hwirq);
 	spin_unlock_irqrestore(&priv->lock, flags);
 }

 static int ts5500_dio_probe(struct platform_device *pdev)
 {
 	enum ts5500_blocks block = platform_get_device_id(pdev)->driver_data;
 	struct ts5500_dio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct device *dev = &pdev->dev;
 	const char *name = dev_name(dev);
 	struct ts5500_priv *priv;
 	struct resource *res;
 	unsigned long flags;
 	int ret;

 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (!res) {
 		dev_err(dev, "missing IRQ resource\n");
 		return -EINVAL;
 	}

 	priv = devm_kzalloc(dev, sizeof(struct ts5500_priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, priv);
 	priv->hwirq = res->start;
 	spin_lock_init(&priv->lock);

 	priv->gpio_chip.owner = THIS_MODULE;
 	priv->gpio_chip.label = name;
 	priv->gpio_chip.parent = dev;
 	priv->gpio_chip.direction_input = ts5500_gpio_input;
 	priv->gpio_chip.direction_output = ts5500_gpio_output;
 	priv->gpio_chip.get = ts5500_gpio_get;
 	priv->gpio_chip.set = ts5500_gpio_set;
 	priv->gpio_chip.to_irq = ts5500_gpio_to_irq;
 	priv->gpio_chip.base = -1;
 	if (pdata) {
 		priv->gpio_chip.base = pdata->base;
 		priv->strap = pdata->strap;
 	}

 	switch (block) {
 	case TS5500_DIO1:
 		priv->pinout = ts5500_dio1;
 		priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio1);

 		if (!devm_request_region(dev, 0x7a, 3, name)) {
 			dev_err(dev, "failed to request %s ports\n", name);
 			return -EBUSY;
 		}
 		break;
 	case TS5500_DIO2:
 		priv->pinout = ts5500_dio2;
 		priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio2);

 		if (!devm_request_region(dev, 0x7e, 2, name)) {
 			dev_err(dev, "failed to request %s ports\n", name);
 			return -EBUSY;
 		}

 		if (hex7d_reserved)
 			break;

 		if (!devm_request_region(dev, 0x7d, 1, name)) {
 			dev_err(dev, "failed to request %s 7D\n", name);
 			return -EBUSY;
 		}

 		hex7d_reserved = true;
 		break;
 	case TS5500_LCD:
 	case TS5600_LCD:
 		priv->pinout = ts5500_lcd;
 		priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_lcd);

 		if (!devm_request_region(dev, 0x72, 2, name)) {
 			dev_err(dev, "failed to request %s ports\n", name);
 			return -EBUSY;
 		}

 		if (!hex7d_reserved) {
 			if (!devm_request_region(dev, 0x7d, 1, name)) {
 				dev_err(dev, "failed to request %s 7D\n", name);
 				return -EBUSY;
 			}

 			hex7d_reserved = true;
 		}

 		/* Ensure usage of LCD port as DIO */
 		spin_lock_irqsave(&priv->lock, flags);
 		ts5500_clear_mask(BIT(4), 0x7d);
 		spin_unlock_irqrestore(&priv->lock, flags);
 		break;
 	}

 	ret = gpiochip_add_data(&priv->gpio_chip, priv);
 	if (ret) {
 		dev_err(dev, "failed to register the gpio chip\n");
 		return ret;
 	}

 	ret = ts5500_enable_irq(priv);
 	if (ret) {
 		dev_err(dev, "invalid interrupt %d\n", priv->hwirq);
 		goto cleanup;
 	}

 	return 0;
 cleanup:
 	gpiochip_remove(&priv->gpio_chip);
 	return ret;
 }

 static int ts5500_dio_remove(struct platform_device *pdev)
 {
 	struct ts5500_priv *priv = platform_get_drvdata(pdev);

 	ts5500_disable_irq(priv);
 	gpiochip_remove(&priv->gpio_chip);
 	return 0;
 }

 static const struct platform_device_id ts5500_dio_ids[] = {
 	{ "ts5500-dio1", TS5500_DIO1 },
 	{ "ts5500-dio2", TS5500_DIO2 },
 	{ "ts5500-dio-lcd", TS5500_LCD },
 	{ "ts5600-dio-lcd", TS5600_LCD },
 	{ }
 };
 MODULE_DEVICE_TABLE(platform, ts5500_dio_ids);

 static struct platform_driver ts5500_dio_driver = {
 	.driver = {
 		.name = "ts5500-dio",
 	},
 	.probe = ts5500_dio_probe,
 	.remove = ts5500_dio_remove,
 	.id_table = ts5500_dio_ids,
 };

 module_platform_driver(ts5500_dio_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>");
 MODULE_DESCRIPTION("Technologic Systems TS-5500 Digital I/O driver");
	/*
	* Digital I/O driver for Technologic Systems TS-5500
	*
	* Copyright (c) 2012 Savoir-faire Linux Inc.
	* Vivien Didelot <vivien.didelot@savoirfairelinux.com>
	*
	* Technologic Systems platforms have pin blocks, exposing several Digital
	* Input/Output lines (DIO). This driver aims to support single pin blocks.
	* In that sense, the support is not limited to the TS-5500 blocks.
	* Actually, the following platforms have DIO support:
	*
	* TS-5500:
	* Documentation: http://wiki.embeddedarm.com/wiki/TS-5500
	* Blocks: DIO1, DIO2 and LCD port.
	*
	* TS-5600:
	* Documentation: http://wiki.embeddedarm.com/wiki/TS-5600
	* Blocks: LCD port (identical to TS-5500 LCD).
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/bitops.h>
	#include <linux/gpio.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/platform_data/gpio-ts5500.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>

	/* List of supported Technologic Systems platforms DIO blocks */
	enum ts5500_blocks { TS5500_DIO1, TS5500_DIO2, TS5500_LCD, TS5600_LCD };

	struct ts5500_priv {
	const struct ts5500_dio *pinout;
	struct gpio_chip gpio_chip;
	spinlock_t lock;
	bool strap;
	u8 hwirq;
	};

	/*
	* Hex 7D is used to control several blocks (e.g. DIO2 and LCD port).
	* This flag ensures that the region has been requested by this driver.
	*/
	static bool hex7d_reserved;

	/*
	* This structure is used to describe capabilities of DIO lines,
	* such as available directions and connected interrupt (if any).
	*/
	struct ts5500_dio {
	const u8 value_addr;
	const u8 value_mask;
	const u8 control_addr;
	const u8 control_mask;
	const bool no_input;
	const bool no_output;
	const u8 irq;
	};

	#define TS5500_DIO_IN_OUT(vaddr, vbit, caddr, cbit) \
	{ \
	.value_addr = vaddr, \
	.value_mask = BIT(vbit), \
	.control_addr = caddr, \
	.control_mask = BIT(cbit), \
	}

	#define TS5500_DIO_IN(addr, bit) \
	{ \
	.value_addr = addr, \
	.value_mask = BIT(bit), \
	.no_output = true, \
	}

	#define TS5500_DIO_IN_IRQ(addr, bit, _irq) \
	{ \
	.value_addr = addr, \
	.value_mask = BIT(bit), \
	.no_output = true, \
	.irq = _irq, \
	}

	#define TS5500_DIO_OUT(addr, bit) \
	{ \
	.value_addr = addr, \
	.value_mask = BIT(bit), \
	.no_input = true, \
	}

	/*
	* Input/Output DIO lines are programmed in groups of 4. Their values are
	* available through 4 consecutive bits in a value port, whereas the direction
	* of these 4 lines is driven by only 1 bit in a control port.
	*/
	#define TS5500_DIO_GROUP(vaddr, vbitfrom, caddr, cbit) \
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 0, caddr, cbit), \
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 1, caddr, cbit), \
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 2, caddr, cbit), \
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 3, caddr, cbit)

	/*
	* TS-5500 DIO1 block
	*
	* value control dir hw
	* addr bit addr bit in out irq name pin offset
	*
	* 0x7b 0 0x7a 0 x x DIO1_0 1 0
	* 0x7b 1 0x7a 0 x x DIO1_1 3 1
	* 0x7b 2 0x7a 0 x x DIO1_2 5 2
	* 0x7b 3 0x7a 0 x x DIO1_3 7 3
	* 0x7b 4 0x7a 1 x x DIO1_4 9 4
	* 0x7b 5 0x7a 1 x x DIO1_5 11 5
	* 0x7b 6 0x7a 1 x x DIO1_6 13 6
	* 0x7b 7 0x7a 1 x x DIO1_7 15 7
	* 0x7c 0 0x7a 5 x x DIO1_8 4 8
	* 0x7c 1 0x7a 5 x x DIO1_9 6 9
	* 0x7c 2 0x7a 5 x x DIO1_10 8 10
	* 0x7c 3 0x7a 5 x x DIO1_11 10 11
	* 0x7c 4 x DIO1_12 12 12
	* 0x7c 5 x 7 DIO1_13 14 13
	*/
	static const struct ts5500_dio ts5500_dio1[] = {
	TS5500_DIO_GROUP(0x7b, 0, 0x7a, 0),
	TS5500_DIO_GROUP(0x7b, 4, 0x7a, 1),
	TS5500_DIO_GROUP(0x7c, 0, 0x7a, 5),
	TS5500_DIO_IN(0x7c, 4),
	TS5500_DIO_IN_IRQ(0x7c, 5, 7),
	};

	/*
	* TS-5500 DIO2 block
	*
	* value control dir hw
	* addr bit addr bit in out irq name pin offset
	*
	* 0x7e 0 0x7d 0 x x DIO2_0 1 0
	* 0x7e 1 0x7d 0 x x DIO2_1 3 1
	* 0x7e 2 0x7d 0 x x DIO2_2 5 2
	* 0x7e 3 0x7d 0 x x DIO2_3 7 3
	* 0x7e 4 0x7d 1 x x DIO2_4 9 4
	* 0x7e 5 0x7d 1 x x DIO2_5 11 5
	* 0x7e 6 0x7d 1 x x DIO2_6 13 6
	* 0x7e 7 0x7d 1 x x DIO2_7 15 7
	* 0x7f 0 0x7d 5 x x DIO2_8 4 8
	* 0x7f 1 0x7d 5 x x DIO2_9 6 9
	* 0x7f 2 0x7d 5 x x DIO2_10 8 10
	* 0x7f 3 0x7d 5 x x DIO2_11 10 11
	* 0x7f 4 x 6 DIO2_13 14 12
	*/
	static const struct ts5500_dio ts5500_dio2[] = {
	TS5500_DIO_GROUP(0x7e, 0, 0x7d, 0),
	TS5500_DIO_GROUP(0x7e, 4, 0x7d, 1),
	TS5500_DIO_GROUP(0x7f, 0, 0x7d, 5),
	TS5500_DIO_IN_IRQ(0x7f, 4, 6),
	};

	/*
	* TS-5500 LCD port used as DIO block
	* TS-5600 LCD port is identical
	*
	* value control dir hw
	* addr bit addr bit in out irq name pin offset
	*
	* 0x72 0 0x7d 2 x x LCD_0 8 0
	* 0x72 1 0x7d 2 x x LCD_1 7 1
	* 0x72 2 0x7d 2 x x LCD_2 10 2
	* 0x72 3 0x7d 2 x x LCD_3 9 3
	* 0x72 4 0x7d 3 x x LCD_4 12 4
	* 0x72 5 0x7d 3 x x LCD_5 11 5
	* 0x72 6 0x7d 3 x x LCD_6 14 6
	* 0x72 7 0x7d 3 x x LCD_7 13 7
	* 0x73 0 x LCD_EN 5 8
	* 0x73 6 x LCD_WR 6 9
	* 0x73 7 x 1 LCD_RS 3 10
	*/
	static const struct ts5500_dio ts5500_lcd[] = {
	TS5500_DIO_GROUP(0x72, 0, 0x7d, 2),
	TS5500_DIO_GROUP(0x72, 4, 0x7d, 3),
	TS5500_DIO_OUT(0x73, 0),
	TS5500_DIO_IN(0x73, 6),
	TS5500_DIO_IN_IRQ(0x73, 7, 1),
	};

	static inline void ts5500_set_mask(u8 mask, u8 addr)
	{
	u8 val = inb(addr);
	val \|= mask;
	outb(val, addr);
	}

	static inline void ts5500_clear_mask(u8 mask, u8 addr)
	{
	u8 val = inb(addr);
	val &= ~mask;
	outb(val, addr);
	}

	static int ts5500_gpio_input(struct gpio_chip *chip, unsigned offset)
	{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];
	unsigned long flags;

	if (line.no_input)
	return -ENXIO;

	if (line.no_output)
	return 0;

	spin_lock_irqsave(&priv->lock, flags);
	ts5500_clear_mask(line.control_mask, line.control_addr);
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
	}

	static int ts5500_gpio_get(struct gpio_chip *chip, unsigned offset)
	{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];

	return !!(inb(line.value_addr) & line.value_mask);
	}

	static int ts5500_gpio_output(struct gpio_chip *chip, unsigned offset, int val)
	{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];
	unsigned long flags;

	if (line.no_output)
	return -ENXIO;

	spin_lock_irqsave(&priv->lock, flags);
	if (!line.no_input)
	ts5500_set_mask(line.control_mask, line.control_addr);

	if (val)
	ts5500_set_mask(line.value_mask, line.value_addr);
	else
	ts5500_clear_mask(line.value_mask, line.value_addr);
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
	}

	static void ts5500_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
	{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (val)
	ts5500_set_mask(line.value_mask, line.value_addr);
	else
	ts5500_clear_mask(line.value_mask, line.value_addr);
	spin_unlock_irqrestore(&priv->lock, flags);
	}

	static int ts5500_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
	{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio *block = priv->pinout;
	const struct ts5500_dio line = block[offset];

	/* Only one pin is connected to an interrupt */
	if (line.irq)
	return line.irq;

	/* As this pin is input-only, we may strap it to another in/out pin */
	if (priv->strap)
	return priv->hwirq;

	return -ENXIO;
	}

	static int ts5500_enable_irq(struct ts5500_priv *priv)
	{
	int ret = 0;
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->hwirq == 7)
	ts5500_set_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
	else if (priv->hwirq == 6)
	ts5500_set_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
	else if (priv->hwirq == 1)
	ts5500_set_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
	else
	ret = -EINVAL;
	spin_unlock_irqrestore(&priv->lock, flags);

	return ret;
	}

	static void ts5500_disable_irq(struct ts5500_priv *priv)
	{
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->hwirq == 7)
	ts5500_clear_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
	else if (priv->hwirq == 6)
	ts5500_clear_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
	else if (priv->hwirq == 1)
	ts5500_clear_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
	else
	dev_err(priv->gpio_chip.parent, "invalid hwirq %d\n",
	priv->hwirq);
	spin_unlock_irqrestore(&priv->lock, flags);
	}

	static int ts5500_dio_probe(struct platform_device *pdev)
	{
	enum ts5500_blocks block = platform_get_device_id(pdev)->driver_data;
	struct ts5500_dio_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct device *dev = &pdev->dev;
	const char *name = dev_name(dev);
	struct ts5500_priv *priv;
	struct resource *res;
	unsigned long flags;
	int ret;

	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!res) {
	dev_err(dev, "missing IRQ resource\n");
	return -EINVAL;
	}

	priv = devm_kzalloc(dev, sizeof(struct ts5500_priv), GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	platform_set_drvdata(pdev, priv);
	priv->hwirq = res->start;
	spin_lock_init(&priv->lock);

	priv->gpio_chip.owner = THIS_MODULE;
	priv->gpio_chip.label = name;
	priv->gpio_chip.parent = dev;
	priv->gpio_chip.direction_input = ts5500_gpio_input;
	priv->gpio_chip.direction_output = ts5500_gpio_output;
	priv->gpio_chip.get = ts5500_gpio_get;
	priv->gpio_chip.set = ts5500_gpio_set;
	priv->gpio_chip.to_irq = ts5500_gpio_to_irq;
	priv->gpio_chip.base = -1;
	if (pdata) {
	priv->gpio_chip.base = pdata->base;
	priv->strap = pdata->strap;
	}

	switch (block) {
	case TS5500_DIO1:
	priv->pinout = ts5500_dio1;
	priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio1);

	if (!devm_request_region(dev, 0x7a, 3, name)) {
	dev_err(dev, "failed to request %s ports\n", name);
	return -EBUSY;
	}
	break;
	case TS5500_DIO2:
	priv->pinout = ts5500_dio2;
	priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio2);

	if (!devm_request_region(dev, 0x7e, 2, name)) {
	dev_err(dev, "failed to request %s ports\n", name);
	return -EBUSY;
	}

	if (hex7d_reserved)
	break;

	if (!devm_request_region(dev, 0x7d, 1, name)) {
	dev_err(dev, "failed to request %s 7D\n", name);
	return -EBUSY;
	}

	hex7d_reserved = true;
	break;
	case TS5500_LCD:
	case TS5600_LCD:
	priv->pinout = ts5500_lcd;
	priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_lcd);

	if (!devm_request_region(dev, 0x72, 2, name)) {
	dev_err(dev, "failed to request %s ports\n", name);
	return -EBUSY;
	}

	if (!hex7d_reserved) {
	if (!devm_request_region(dev, 0x7d, 1, name)) {
	dev_err(dev, "failed to request %s 7D\n", name);
	return -EBUSY;
	}

	hex7d_reserved = true;
	}

	/* Ensure usage of LCD port as DIO */
	spin_lock_irqsave(&priv->lock, flags);
	ts5500_clear_mask(BIT(4), 0x7d);
	spin_unlock_irqrestore(&priv->lock, flags);
	break;
	}

	ret = gpiochip_add_data(&priv->gpio_chip, priv);
	if (ret) {
	dev_err(dev, "failed to register the gpio chip\n");
	return ret;
	}

	ret = ts5500_enable_irq(priv);
	if (ret) {
	dev_err(dev, "invalid interrupt %d\n", priv->hwirq);
	goto cleanup;
	}

	return 0;
	cleanup:
	gpiochip_remove(&priv->gpio_chip);
	return ret;
	}

	static int ts5500_dio_remove(struct platform_device *pdev)
	{
	struct ts5500_priv *priv = platform_get_drvdata(pdev);

	ts5500_disable_irq(priv);
	gpiochip_remove(&priv->gpio_chip);
	return 0;
	}

	static const struct platform_device_id ts5500_dio_ids[] = {
	{ "ts5500-dio1", TS5500_DIO1 },
	{ "ts5500-dio2", TS5500_DIO2 },
	{ "ts5500-dio-lcd", TS5500_LCD },
	{ "ts5600-dio-lcd", TS5600_LCD },
	{ }
	};
	MODULE_DEVICE_TABLE(platform, ts5500_dio_ids);

	static struct platform_driver ts5500_dio_driver = {
	.driver = {
	.name = "ts5500-dio",
	},
	.probe = ts5500_dio_probe,
	.remove = ts5500_dio_remove,
	.id_table = ts5500_dio_ids,
	};

	module_platform_driver(ts5500_dio_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>");
	MODULE_DESCRIPTION("Technologic Systems TS-5500 Digital I/O driver");