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Release 4.7 drivers/gpio/gpio-ts5500.c

Directory: drivers/gpio
/*
 * 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); }

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

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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; }

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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); }

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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; }

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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); }

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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; }

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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; }

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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); }

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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 = devm_gpiochip_add_data(dev, &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); return ret; } return 0; }

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static int ts5500_dio_remove(struct platform_device *pdev) { struct ts5500_priv *priv = platform_get_drvdata(pdev); ts5500_disable_irq(priv); return 0; }

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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");

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Directory: drivers/gpio
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