[mirror_ubuntu-focal-kernel.git] / drivers / mfd / htc-i2cpld.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  htc-i2cpld.c
 *  Chip driver for an unknown CPLD chip found on omap850 HTC devices like
 *  the HTC Wizard and HTC Herald.
 *  The cpld is located on the i2c bus and acts as an input/output GPIO
 *  extender.
 *
 *  Copyright (C) 2009 Cory Maccarrone <darkstar6262@gmail.com>
 *
 *  Based on work done in the linwizard project
 *  Copyright (C) 2008-2009 Angelo Arrifano <miknix@gmail.com>
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/irq.h>
#include <linux/spinlock.h>
#include <linux/htcpld.h>
#include <linux/gpio.h>
#include <linux/slab.h>

struct htcpld_chip {
	spinlock_t              lock;

	/* chip info */
	u8                      reset;
	u8                      addr;
	struct device           *dev;
	struct i2c_client	*client;

	/* Output details */
	u8                      cache_out;
	struct gpio_chip        chip_out;

	/* Input details */
	u8                      cache_in;
	struct gpio_chip        chip_in;

	u16                     irqs_enabled;
	uint                    irq_start;
	int                     nirqs;

	unsigned int		flow_type;
	/*
	 * Work structure to allow for setting values outside of any
	 * possible interrupt context
	 */
	struct work_struct set_val_work;
};

struct htcpld_data {
	/* irq info */
	u16                irqs_enabled;
	uint               irq_start;
	int                nirqs;
	uint               chained_irq;
	unsigned int       int_reset_gpio_hi;
	unsigned int       int_reset_gpio_lo;

	/* htcpld info */
	struct htcpld_chip *chip;
	unsigned int       nchips;
};

/* There does not appear to be a way to proactively mask interrupts
 * on the htcpld chip itself.  So, we simply ignore interrupts that
 * aren't desired. */
static void htcpld_mask(struct irq_data *data)
{
	struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
	chip->irqs_enabled &= ~(1 << (data->irq - chip->irq_start));
	pr_debug("HTCPLD mask %d %04x\n", data->irq, chip->irqs_enabled);
}
static void htcpld_unmask(struct irq_data *data)
{
	struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
	chip->irqs_enabled |= 1 << (data->irq - chip->irq_start);
	pr_debug("HTCPLD unmask %d %04x\n", data->irq, chip->irqs_enabled);
}

static int htcpld_set_type(struct irq_data *data, unsigned int flags)
{
	struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);

	if (flags & ~IRQ_TYPE_SENSE_MASK)
		return -EINVAL;

	/* We only allow edge triggering */
	if (flags & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH))
		return -EINVAL;

	chip->flow_type = flags;
	return 0;
}

static struct irq_chip htcpld_muxed_chip = {
	.name         = "htcpld",
	.irq_mask     = htcpld_mask,
	.irq_unmask   = htcpld_unmask,
	.irq_set_type = htcpld_set_type,
};

/* To properly dispatch IRQ events, we need to read from the
 * chip.  This is an I2C action that could possibly sleep
 * (which is bad in interrupt context) -- so we use a threaded
 * interrupt handler to get around that.
 */
static irqreturn_t htcpld_handler(int irq, void *dev)
{
	struct htcpld_data *htcpld = dev;
	unsigned int i;
	unsigned long flags;
	int irqpin;

	if (!htcpld) {
		pr_debug("htcpld is null in ISR\n");
		return IRQ_HANDLED;
	}

	/*
	 * For each chip, do a read of the chip and trigger any interrupts
	 * desired.  The interrupts will be triggered from LSB to MSB (i.e.
	 * bit 0 first, then bit 1, etc.)
	 *
	 * For chips that have no interrupt range specified, just skip 'em.
	 */
	for (i = 0; i < htcpld->nchips; i++) {
		struct htcpld_chip *chip = &htcpld->chip[i];
		struct i2c_client *client;
		int val;
		unsigned long uval, old_val;

		if (!chip) {
			pr_debug("chip %d is null in ISR\n", i);
			continue;
		}

		if (chip->nirqs == 0)
			continue;

		client = chip->client;
		if (!client) {
			pr_debug("client %d is null in ISR\n", i);
			continue;
		}

		/* Scan the chip */
		val = i2c_smbus_read_byte_data(client, chip->cache_out);
		if (val < 0) {
			/* Throw a warning and skip this chip */
			dev_warn(chip->dev, "Unable to read from chip: %d\n",
				 val);
			continue;
		}

		uval = (unsigned long)val;

		spin_lock_irqsave(&chip->lock, flags);

		/* Save away the old value so we can compare it */
		old_val = chip->cache_in;

		/* Write the new value */
		chip->cache_in = uval;

		spin_unlock_irqrestore(&chip->lock, flags);

		/*
		 * For each bit in the data (starting at bit 0), trigger
		 * associated interrupts.
		 */
		for (irqpin = 0; irqpin < chip->nirqs; irqpin++) {
			unsigned oldb, newb, type = chip->flow_type;

			irq = chip->irq_start + irqpin;

			/* Run the IRQ handler, but only if the bit value
			 * changed, and the proper flags are set */
			oldb = (old_val >> irqpin) & 1;
			newb = (uval >> irqpin) & 1;

			if ((!oldb && newb && (type & IRQ_TYPE_EDGE_RISING)) ||
			    (oldb && !newb && (type & IRQ_TYPE_EDGE_FALLING))) {
				pr_debug("fire IRQ %d\n", irqpin);
				generic_handle_irq(irq);
			}
		}
	}

	/*
	 * In order to continue receiving interrupts, the int_reset_gpio must
	 * be asserted.
	 */
	if (htcpld->int_reset_gpio_hi)
		gpio_set_value(htcpld->int_reset_gpio_hi, 1);
	if (htcpld->int_reset_gpio_lo)
		gpio_set_value(htcpld->int_reset_gpio_lo, 0);

	return IRQ_HANDLED;
}

/*
 * The GPIO set routines can be called from interrupt context, especially if,
 * for example they're attached to the led-gpio framework and a trigger is
 * enabled.  As such, we declared work above in the htcpld_chip structure,
 * and that work is scheduled in the set routine.  The kernel can then run
 * the I2C functions, which will sleep, in process context.
 */
static void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
{
	struct i2c_client *client;
	struct htcpld_chip *chip_data = gpiochip_get_data(chip);
	unsigned long flags;

	client = chip_data->client;
	if (!client)
		return;

	spin_lock_irqsave(&chip_data->lock, flags);
	if (val)
		chip_data->cache_out |= (1 << offset);
	else
		chip_data->cache_out &= ~(1 << offset);
	spin_unlock_irqrestore(&chip_data->lock, flags);

	schedule_work(&(chip_data->set_val_work));
}

static void htcpld_chip_set_ni(struct work_struct *work)
{
	struct htcpld_chip *chip_data;
	struct i2c_client *client;

	chip_data = container_of(work, struct htcpld_chip, set_val_work);
	client = chip_data->client;
	i2c_smbus_read_byte_data(client, chip_data->cache_out);
}

static int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
{
	struct htcpld_chip *chip_data = gpiochip_get_data(chip);
	u8 cache;

	if (!strncmp(chip->label, "htcpld-out", 10)) {
		cache = chip_data->cache_out;
	} else if (!strncmp(chip->label, "htcpld-in", 9)) {
		cache = chip_data->cache_in;
	} else
		return -EINVAL;

	return (cache >> offset) & 1;
}

static int htcpld_direction_output(struct gpio_chip *chip,
					unsigned offset, int value)
{
	htcpld_chip_set(chip, offset, value);
	return 0;
}

static int htcpld_direction_input(struct gpio_chip *chip,
					unsigned offset)
{
	/*
	 * No-op: this function can only be called on the input chip.
	 * We do however make sure the offset is within range.
	 */
	return (offset < chip->ngpio) ? 0 : -EINVAL;
}

static int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct htcpld_chip *chip_data = gpiochip_get_data(chip);

	if (offset < chip_data->nirqs)
		return chip_data->irq_start + offset;
	else
		return -EINVAL;
}

static void htcpld_chip_reset(struct i2c_client *client)
{
	struct htcpld_chip *chip_data = i2c_get_clientdata(client);
	if (!chip_data)
		return;

	i2c_smbus_read_byte_data(
		client, (chip_data->cache_out = chip_data->reset));
}

static int htcpld_setup_chip_irq(
		struct platform_device *pdev,
		int chip_index)
{
	struct htcpld_data *htcpld;
	struct htcpld_chip *chip;
	unsigned int irq, irq_end;

	/* Get the platform and driver data */
	htcpld = platform_get_drvdata(pdev);
	chip = &htcpld->chip[chip_index];

	/* Setup irq handlers */
	irq_end = chip->irq_start + chip->nirqs;
	for (irq = chip->irq_start; irq < irq_end; irq++) {
		irq_set_chip_and_handler(irq, &htcpld_muxed_chip,
					 handle_simple_irq);
		irq_set_chip_data(irq, chip);
		irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
	}

	return 0;
}

static int htcpld_register_chip_i2c(
		struct platform_device *pdev,
		int chip_index)
{
	struct htcpld_data *htcpld;
	struct device *dev = &pdev->dev;
	struct htcpld_core_platform_data *pdata;
	struct htcpld_chip *chip;
	struct htcpld_chip_platform_data *plat_chip_data;
	struct i2c_adapter *adapter;
	struct i2c_client *client;
	struct i2c_board_info info;

	/* Get the platform and driver data */
	pdata = dev_get_platdata(dev);
	htcpld = platform_get_drvdata(pdev);
	chip = &htcpld->chip[chip_index];
	plat_chip_data = &pdata->chip[chip_index];

	adapter = i2c_get_adapter(pdata->i2c_adapter_id);
	if (!adapter) {
		/* Eek, no such I2C adapter!  Bail out. */
		dev_warn(dev, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
			 plat_chip_data->addr, pdata->i2c_adapter_id);
		return -ENODEV;
	}

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
		dev_warn(dev, "i2c adapter %d non-functional\n",
			 pdata->i2c_adapter_id);
		return -EINVAL;
	}

	memset(&info, 0, sizeof(struct i2c_board_info));
	info.addr = plat_chip_data->addr;
	strlcpy(info.type, "htcpld-chip", I2C_NAME_SIZE);
	info.platform_data = chip;

	/* Add the I2C device.  This calls the probe() function. */
	client = i2c_new_device(adapter, &info);
	if (!client) {
		/* I2C device registration failed, contineu with the next */
		dev_warn(dev, "Unable to add I2C device for 0x%x\n",
			 plat_chip_data->addr);
		return -ENODEV;
	}

	i2c_set_clientdata(client, chip);
	snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%x", client->addr);
	chip->client = client;

	/* Reset the chip */
	htcpld_chip_reset(client);
	chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out);

	return 0;
}

static void htcpld_unregister_chip_i2c(
		struct platform_device *pdev,
		int chip_index)
{
	struct htcpld_data *htcpld;
	struct htcpld_chip *chip;

	/* Get the platform and driver data */
	htcpld = platform_get_drvdata(pdev);
	chip = &htcpld->chip[chip_index];

	i2c_unregister_device(chip->client);
}

static int htcpld_register_chip_gpio(
		struct platform_device *pdev,
		int chip_index)
{
	struct htcpld_data *htcpld;
	struct device *dev = &pdev->dev;
	struct htcpld_core_platform_data *pdata;
	struct htcpld_chip *chip;
	struct htcpld_chip_platform_data *plat_chip_data;
	struct gpio_chip *gpio_chip;
	int ret = 0;

	/* Get the platform and driver data */
	pdata = dev_get_platdata(dev);
	htcpld = platform_get_drvdata(pdev);
	chip = &htcpld->chip[chip_index];
	plat_chip_data = &pdata->chip[chip_index];

	/* Setup the GPIO chips */
	gpio_chip = &(chip->chip_out);
	gpio_chip->label           = "htcpld-out";
	gpio_chip->parent             = dev;
	gpio_chip->owner           = THIS_MODULE;
	gpio_chip->get             = htcpld_chip_get;
	gpio_chip->set             = htcpld_chip_set;
	gpio_chip->direction_input = NULL;
	gpio_chip->direction_output = htcpld_direction_output;
	gpio_chip->base            = plat_chip_data->gpio_out_base;
	gpio_chip->ngpio           = plat_chip_data->num_gpios;

	gpio_chip = &(chip->chip_in);
	gpio_chip->label           = "htcpld-in";
	gpio_chip->parent             = dev;
	gpio_chip->owner           = THIS_MODULE;
	gpio_chip->get             = htcpld_chip_get;
	gpio_chip->set             = NULL;
	gpio_chip->direction_input = htcpld_direction_input;
	gpio_chip->direction_output = NULL;
	gpio_chip->to_irq          = htcpld_chip_to_irq;
	gpio_chip->base            = plat_chip_data->gpio_in_base;
	gpio_chip->ngpio           = plat_chip_data->num_gpios;

	/* Add the GPIO chips */
	ret = gpiochip_add_data(&(chip->chip_out), chip);
	if (ret) {
		dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n",
			 plat_chip_data->addr, ret);
		return ret;
	}

	ret = gpiochip_add_data(&(chip->chip_in), chip);
	if (ret) {
		dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
			 plat_chip_data->addr, ret);
		gpiochip_remove(&(chip->chip_out));
		return ret;
	}

	return 0;
}

static int htcpld_setup_chips(struct platform_device *pdev)
{
	struct htcpld_data *htcpld;
	struct device *dev = &pdev->dev;
	struct htcpld_core_platform_data *pdata;
	int i;

	/* Get the platform and driver data */
	pdata = dev_get_platdata(dev);
	htcpld = platform_get_drvdata(pdev);

	/* Setup each chip's output GPIOs */
	htcpld->nchips = pdata->num_chip;
	htcpld->chip = devm_kcalloc(dev,
				    htcpld->nchips,
				    sizeof(struct htcpld_chip),
				    GFP_KERNEL);
	if (!htcpld->chip)
		return -ENOMEM;

	/* Add the chips as best we can */
	for (i = 0; i < htcpld->nchips; i++) {
		int ret;

		/* Setup the HTCPLD chips */
		htcpld->chip[i].reset = pdata->chip[i].reset;
		htcpld->chip[i].cache_out = pdata->chip[i].reset;
		htcpld->chip[i].cache_in = 0;
		htcpld->chip[i].dev = dev;
		htcpld->chip[i].irq_start = pdata->chip[i].irq_base;
		htcpld->chip[i].nirqs = pdata->chip[i].num_irqs;

		INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni);
		spin_lock_init(&(htcpld->chip[i].lock));

		/* Setup the interrupts for the chip */
		if (htcpld->chained_irq) {
			ret = htcpld_setup_chip_irq(pdev, i);
			if (ret)
				continue;
		}

		/* Register the chip with I2C */
		ret = htcpld_register_chip_i2c(pdev, i);
		if (ret)
			continue;


		/* Register the chips with the GPIO subsystem */
		ret = htcpld_register_chip_gpio(pdev, i);
		if (ret) {
			/* Unregister the chip from i2c and continue */
			htcpld_unregister_chip_i2c(pdev, i);
			continue;
		}

		dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr);
	}

	return 0;
}

static int htcpld_core_probe(struct platform_device *pdev)
{
	struct htcpld_data *htcpld;
	struct device *dev = &pdev->dev;
	struct htcpld_core_platform_data *pdata;
	struct resource *res;
	int ret = 0;

	if (!dev)
		return -ENODEV;

	pdata = dev_get_platdata(dev);
	if (!pdata) {
		dev_warn(dev, "Platform data not found for htcpld core!\n");
		return -ENXIO;
	}

	htcpld = devm_kzalloc(dev, sizeof(struct htcpld_data), GFP_KERNEL);
	if (!htcpld)
		return -ENOMEM;

	/* Find chained irq */
	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (res) {
		int flags;
		htcpld->chained_irq = res->start;

		/* Setup the chained interrupt handler */
		flags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
			IRQF_ONESHOT;
		ret = request_threaded_irq(htcpld->chained_irq,
					   NULL, htcpld_handler,
					   flags, pdev->name, htcpld);
		if (ret) {
			dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret);
			return ret;
		} else
			device_init_wakeup(dev, 0);
	}

	/* Set the driver data */
	platform_set_drvdata(pdev, htcpld);

	/* Setup the htcpld chips */
	ret = htcpld_setup_chips(pdev);
	if (ret)
		return ret;

	/* Request the GPIO(s) for the int reset and set them up */
	if (pdata->int_reset_gpio_hi) {
		ret = gpio_request(pdata->int_reset_gpio_hi, "htcpld-core");
		if (ret) {
			/*
			 * If it failed, that sucks, but we can probably
			 * continue on without it.
			 */
			dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
			htcpld->int_reset_gpio_hi = 0;
		} else {
			htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi;
			gpio_set_value(htcpld->int_reset_gpio_hi, 1);
		}
	}

	if (pdata->int_reset_gpio_lo) {
		ret = gpio_request(pdata->int_reset_gpio_lo, "htcpld-core");
		if (ret) {
			/*
			 * If it failed, that sucks, but we can probably
			 * continue on without it.
			 */
			dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
			htcpld->int_reset_gpio_lo = 0;
		} else {
			htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo;
			gpio_set_value(htcpld->int_reset_gpio_lo, 0);
		}
	}

	dev_info(dev, "Initialized successfully\n");
	return 0;
}

/* The I2C Driver -- used internally */
static const struct i2c_device_id htcpld_chip_id[] = {
	{ "htcpld-chip", 0 },
	{ }
};

static struct i2c_driver htcpld_chip_driver = {
	.driver = {
		.name	= "htcpld-chip",
	},
	.id_table = htcpld_chip_id,
};

/* The Core Driver */
static struct platform_driver htcpld_core_driver = {
	.driver = {
		.name = "i2c-htcpld",
	},
};

static int __init htcpld_core_init(void)
{
	int ret;

	/* Register the I2C Chip driver */
	ret = i2c_add_driver(&htcpld_chip_driver);
	if (ret)
		return ret;

	/* Probe for our chips */
	return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe);
}
device_initcall(htcpld_core_init);
Commit	Line	Data
74ba9207	1	// SPDX-License-Identifier: GPL-2.0-or-later
6048a3dd CM	2	/*
	3	* htc-i2cpld.c
	4	* Chip driver for an unknown CPLD chip found on omap850 HTC devices like
	5	* the HTC Wizard and HTC Herald.
	6	* The cpld is located on the i2c bus and acts as an input/output GPIO
	7	* extender.
	8	*
	9	* Copyright (C) 2009 Cory Maccarrone <darkstar6262@gmail.com>
	10	*
	11	* Based on work done in the linwizard project
	12	* Copyright (C) 2008-2009 Angelo Arrifano <miknix@gmail.com>
6048a3dd CM	13	*/
	14
	15	#include <linux/kernel.h>
	16	#include <linux/init.h>
6048a3dd CM	17	#include <linux/interrupt.h>
	18	#include <linux/platform_device.h>
	19	#include <linux/i2c.h>
	20	#include <linux/irq.h>
	21	#include <linux/spinlock.h>
	22	#include <linux/htcpld.h>
	23	#include <linux/gpio.h>
5a0e3ad6	24	#include <linux/slab.h>
6048a3dd CM	25
	26	struct htcpld_chip {
	27	spinlock_t lock;
	28
	29	/* chip info */
	30	u8 reset;
	31	u8 addr;
	32	struct device *dev;
	33	struct i2c_client *client;
	34
	35	/* Output details */
	36	u8 cache_out;
	37	struct gpio_chip chip_out;
	38
	39	/* Input details */
	40	u8 cache_in;
	41	struct gpio_chip chip_in;
	42
	43	u16 irqs_enabled;
	44	uint irq_start;
	45	int nirqs;
	46
9eaee99e	47	unsigned int flow_type;
6048a3dd CM	48	/*
	49	* Work structure to allow for setting values outside of any
	50	* possible interrupt context
	51	*/
	52	struct work_struct set_val_work;
	53	};
	54
	55	struct htcpld_data {
	56	/* irq info */
	57	u16 irqs_enabled;
	58	uint irq_start;
	59	int nirqs;
	60	uint chained_irq;
	61	unsigned int int_reset_gpio_hi;
	62	unsigned int int_reset_gpio_lo;
	63
	64	/* htcpld info */
	65	struct htcpld_chip *chip;
	66	unsigned int nchips;
	67	};
	68
	69	/* There does not appear to be a way to proactively mask interrupts
	70	* on the htcpld chip itself. So, we simply ignore interrupts that
	71	* aren't desired. */
e6a4c4a4	72	static void htcpld_mask(struct irq_data *data)
6048a3dd	73	{
e6a4c4a4 MB	74	struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
	75	chip->irqs_enabled &= ~(1 << (data->irq - chip->irq_start));
	76	pr_debug("HTCPLD mask %d %04x\n", data->irq, chip->irqs_enabled);
6048a3dd	77	}
e6a4c4a4	78	static void htcpld_unmask(struct irq_data *data)
6048a3dd	79	{
e6a4c4a4 MB	80	struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
	81	chip->irqs_enabled \|= 1 << (data->irq - chip->irq_start);
	82	pr_debug("HTCPLD unmask %d %04x\n", data->irq, chip->irqs_enabled);
6048a3dd CM	83	}
6048a3dd CM	84
e6a4c4a4	85	static int htcpld_set_type(struct irq_data *data, unsigned int flags)
6048a3dd	86	{
9eaee99e	87	struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
6048a3dd CM	88
	89	if (flags & ~IRQ_TYPE_SENSE_MASK)
	90	return -EINVAL;
	91
	92	/* We only allow edge triggering */
	93	if (flags & (IRQ_TYPE_LEVEL_LOW\|IRQ_TYPE_LEVEL_HIGH))
	94	return -EINVAL;
	95
9eaee99e	96	chip->flow_type = flags;
6048a3dd CM	97	return 0;
	98	}
	99
	100	static struct irq_chip htcpld_muxed_chip = {
e6a4c4a4 MB	101	.name = "htcpld",
	102	.irq_mask = htcpld_mask,
	103	.irq_unmask = htcpld_unmask,
	104	.irq_set_type = htcpld_set_type,
6048a3dd CM	105	};
	106
	107	/* To properly dispatch IRQ events, we need to read from the
	108	* chip. This is an I2C action that could possibly sleep
	109	* (which is bad in interrupt context) -- so we use a threaded
	110	* interrupt handler to get around that.
	111	*/
	112	static irqreturn_t htcpld_handler(int irq, void *dev)
	113	{
	114	struct htcpld_data *htcpld = dev;
	115	unsigned int i;
	116	unsigned long flags;
	117	int irqpin;
6048a3dd CM	118
	119	if (!htcpld) {
	120	pr_debug("htcpld is null in ISR\n");
	121	return IRQ_HANDLED;
	122	}
	123
	124	/*
	125	* For each chip, do a read of the chip and trigger any interrupts
	126	* desired. The interrupts will be triggered from LSB to MSB (i.e.
	127	* bit 0 first, then bit 1, etc.)
	128	*
	129	* For chips that have no interrupt range specified, just skip 'em.
	130	*/
	131	for (i = 0; i < htcpld->nchips; i++) {
	132	struct htcpld_chip *chip = &htcpld->chip[i];
	133	struct i2c_client *client;
	134	int val;
	135	unsigned long uval, old_val;
	136
	137	if (!chip) {
	138	pr_debug("chip %d is null in ISR\n", i);
	139	continue;
	140	}
	141
	142	if (chip->nirqs == 0)
	143	continue;
	144
	145	client = chip->client;
	146	if (!client) {
	147	pr_debug("client %d is null in ISR\n", i);
	148	continue;
	149	}
	150
	151	/* Scan the chip */
	152	val = i2c_smbus_read_byte_data(client, chip->cache_out);
	153	if (val < 0) {
	154	/* Throw a warning and skip this chip */
	155	dev_warn(chip->dev, "Unable to read from chip: %d\n",
	156	val);
	157	continue;
	158	}
	159
	160	uval = (unsigned long)val;
	161
	162	spin_lock_irqsave(&chip->lock, flags);
	163
	164	/* Save away the old value so we can compare it */
	165	old_val = chip->cache_in;
	166
	167	/* Write the new value */
	168	chip->cache_in = uval;
	169
	170	spin_unlock_irqrestore(&chip->lock, flags);
	171
	172	/*
	173	* For each bit in the data (starting at bit 0), trigger
	174	* associated interrupts.
	175	*/
	176	for (irqpin = 0; irqpin < chip->nirqs; irqpin++) {
9eaee99e	177	unsigned oldb, newb, type = chip->flow_type;
6048a3dd CM	178
6048a3dd CM	179	irq = chip->irq_start + irqpin;
6048a3dd CM	180
	181	/* Run the IRQ handler, but only if the bit value
	182	* changed, and the proper flags are set */
	183	oldb = (old_val >> irqpin) & 1;
	184	newb = (uval >> irqpin) & 1;
	185
9eaee99e TG	186	if ((!oldb && newb && (type & IRQ_TYPE_EDGE_RISING)) \|\|
9eaee99e TG	187	(oldb && !newb && (type & IRQ_TYPE_EDGE_FALLING))) {
6048a3dd	188	pr_debug("fire IRQ %d\n", irqpin);
9eaee99e	189	generic_handle_irq(irq);
6048a3dd CM	190	}
	191	}
	192	}
	193
	194	/*
	195	* In order to continue receiving interrupts, the int_reset_gpio must
	196	* be asserted.
	197	*/
	198	if (htcpld->int_reset_gpio_hi)
	199	gpio_set_value(htcpld->int_reset_gpio_hi, 1);
	200	if (htcpld->int_reset_gpio_lo)
	201	gpio_set_value(htcpld->int_reset_gpio_lo, 0);
	202
	203	return IRQ_HANDLED;
	204	}
	205
	206	/*
	207	* The GPIO set routines can be called from interrupt context, especially if,
	208	* for example they're attached to the led-gpio framework and a trigger is
	209	* enabled. As such, we declared work above in the htcpld_chip structure,
	210	* and that work is scheduled in the set routine. The kernel can then run
	211	* the I2C functions, which will sleep, in process context.
	212	*/
8d2d3a3a	213	static void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
6048a3dd CM	214	{
6048a3dd CM	215	struct i2c_client *client;
ed1c9b3c	216	struct htcpld_chip *chip_data = gpiochip_get_data(chip);
6048a3dd CM	217	unsigned long flags;
6048a3dd CM	218
6048a3dd	219	client = chip_data->client;
41cc08e9	220	if (!client)
6048a3dd CM	221	return;
	222
	223	spin_lock_irqsave(&chip_data->lock, flags);
	224	if (val)
	225	chip_data->cache_out \|= (1 << offset);
	226	else
	227	chip_data->cache_out &= ~(1 << offset);
	228	spin_unlock_irqrestore(&chip_data->lock, flags);
	229
	230	schedule_work(&(chip_data->set_val_work));
	231	}
	232
8d2d3a3a	233	static void htcpld_chip_set_ni(struct work_struct *work)
6048a3dd CM	234	{
	235	struct htcpld_chip *chip_data;
	236	struct i2c_client *client;
	237
	238	chip_data = container_of(work, struct htcpld_chip, set_val_work);
	239	client = chip_data->client;
	240	i2c_smbus_read_byte_data(client, chip_data->cache_out);
	241	}
	242
8d2d3a3a	243	static int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
6048a3dd	244	{
ed1c9b3c	245	struct htcpld_chip *chip_data = gpiochip_get_data(chip);
9b6a5ad9	246	u8 cache;
6048a3dd	247
9b6a5ad9	248	if (!strncmp(chip->label, "htcpld-out", 10)) {
9b6a5ad9 LJ	249	cache = chip_data->cache_out;
9b6a5ad9 LJ	250	} else if (!strncmp(chip->label, "htcpld-in", 9)) {
9b6a5ad9 LJ	251	cache = chip_data->cache_in;
	252	} else
	253	return -EINVAL;
6048a3dd	254
9b6a5ad9	255	return (cache >> offset) & 1;
6048a3dd CM	256	}
	257
	258	static int htcpld_direction_output(struct gpio_chip *chip,
	259	unsigned offset, int value)
	260	{
	261	htcpld_chip_set(chip, offset, value);
	262	return 0;
	263	}
	264
	265	static int htcpld_direction_input(struct gpio_chip *chip,
	266	unsigned offset)
	267	{
	268	/*
	269	* No-op: this function can only be called on the input chip.
	270	* We do however make sure the offset is within range.
	271	*/
	272	return (offset < chip->ngpio) ? 0 : -EINVAL;
	273	}
	274
8d2d3a3a	275	static int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
6048a3dd	276	{
ed1c9b3c	277	struct htcpld_chip *chip_data = gpiochip_get_data(chip);
6048a3dd CM	278
	279	if (offset < chip_data->nirqs)
	280	return chip_data->irq_start + offset;
	281	else
	282	return -EINVAL;
	283	}
	284
8d2d3a3a	285	static void htcpld_chip_reset(struct i2c_client *client)
6048a3dd CM	286	{
	287	struct htcpld_chip *chip_data = i2c_get_clientdata(client);
	288	if (!chip_data)
	289	return;
	290
	291	i2c_smbus_read_byte_data(
	292	client, (chip_data->cache_out = chip_data->reset));
	293	}
	294
f791be49	295	static int htcpld_setup_chip_irq(
6048a3dd CM	296	struct platform_device *pdev,
	297	int chip_index)
	298	{
	299	struct htcpld_data *htcpld;
6048a3dd	300	struct htcpld_chip *chip;
6048a3dd	301	unsigned int irq, irq_end;
6048a3dd CM	302
6048a3dd CM	303	/* Get the platform and driver data */
6048a3dd CM	304	htcpld = platform_get_drvdata(pdev);
6048a3dd CM	305	chip = &htcpld->chip[chip_index];
6048a3dd CM	306
	307	/* Setup irq handlers */
	308	irq_end = chip->irq_start + chip->nirqs;
	309	for (irq = chip->irq_start; irq < irq_end; irq++) {
d6f7ce9f TG	310	irq_set_chip_and_handler(irq, &htcpld_muxed_chip,
d6f7ce9f TG	311	handle_simple_irq);
d5bb1221	312	irq_set_chip_data(irq, chip);
9bd09f34	313	irq_clear_status_flags(irq, IRQ_NOREQUEST \| IRQ_NOPROBE);
6048a3dd CM	314	}
6048a3dd CM	315
a48baac5	316	return 0;
6048a3dd CM	317	}
6048a3dd CM	318
f791be49	319	static int htcpld_register_chip_i2c(
6048a3dd CM	320	struct platform_device *pdev,
	321	int chip_index)
	322	{
	323	struct htcpld_data *htcpld;
	324	struct device *dev = &pdev->dev;
	325	struct htcpld_core_platform_data *pdata;
	326	struct htcpld_chip *chip;
	327	struct htcpld_chip_platform_data *plat_chip_data;
	328	struct i2c_adapter *adapter;
	329	struct i2c_client *client;
	330	struct i2c_board_info info;
	331
	332	/* Get the platform and driver data */
334a41ce	333	pdata = dev_get_platdata(dev);
6048a3dd CM	334	htcpld = platform_get_drvdata(pdev);
	335	chip = &htcpld->chip[chip_index];
	336	plat_chip_data = &pdata->chip[chip_index];
	337
	338	adapter = i2c_get_adapter(pdata->i2c_adapter_id);
41cc08e9	339	if (!adapter) {
6048a3dd CM	340	/* Eek, no such I2C adapter! Bail out. */
	341	dev_warn(dev, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
	342	plat_chip_data->addr, pdata->i2c_adapter_id);
	343	return -ENODEV;
	344	}
	345
	346	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
	347	dev_warn(dev, "i2c adapter %d non-functional\n",
	348	pdata->i2c_adapter_id);
	349	return -EINVAL;
	350	}
	351
	352	memset(&info, 0, sizeof(struct i2c_board_info));
	353	info.addr = plat_chip_data->addr;
	354	strlcpy(info.type, "htcpld-chip", I2C_NAME_SIZE);
	355	info.platform_data = chip;
	356
	357	/* Add the I2C device. This calls the probe() function. */
	358	client = i2c_new_device(adapter, &info);
	359	if (!client) {
	360	/* I2C device registration failed, contineu with the next */
	361	dev_warn(dev, "Unable to add I2C device for 0x%x\n",
	362	plat_chip_data->addr);
	363	return -ENODEV;
	364	}
	365
	366	i2c_set_clientdata(client, chip);
6065c9a4	367	snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%x", client->addr);
6048a3dd CM	368	chip->client = client;
	369
	370	/* Reset the chip */
	371	htcpld_chip_reset(client);
	372	chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out);
	373
	374	return 0;
	375	}
	376
f791be49	377	static void htcpld_unregister_chip_i2c(
6048a3dd CM	378	struct platform_device *pdev,
	379	int chip_index)
	380	{
	381	struct htcpld_data *htcpld;
	382	struct htcpld_chip *chip;
	383
	384	/* Get the platform and driver data */
	385	htcpld = platform_get_drvdata(pdev);
	386	chip = &htcpld->chip[chip_index];
	387
10944222	388	i2c_unregister_device(chip->client);
6048a3dd CM	389	}
6048a3dd CM	390
f791be49	391	static int htcpld_register_chip_gpio(
6048a3dd CM	392	struct platform_device *pdev,
	393	int chip_index)
	394	{
	395	struct htcpld_data *htcpld;
	396	struct device *dev = &pdev->dev;
	397	struct htcpld_core_platform_data *pdata;
	398	struct htcpld_chip *chip;
	399	struct htcpld_chip_platform_data *plat_chip_data;
	400	struct gpio_chip *gpio_chip;
	401	int ret = 0;
	402
	403	/* Get the platform and driver data */
334a41ce	404	pdata = dev_get_platdata(dev);
6048a3dd CM	405	htcpld = platform_get_drvdata(pdev);
	406	chip = &htcpld->chip[chip_index];
	407	plat_chip_data = &pdata->chip[chip_index];
	408
	409	/* Setup the GPIO chips */
	410	gpio_chip = &(chip->chip_out);
	411	gpio_chip->label = "htcpld-out";
58383c78	412	gpio_chip->parent = dev;
6048a3dd CM	413	gpio_chip->owner = THIS_MODULE;
	414	gpio_chip->get = htcpld_chip_get;
	415	gpio_chip->set = htcpld_chip_set;
	416	gpio_chip->direction_input = NULL;
	417	gpio_chip->direction_output = htcpld_direction_output;
	418	gpio_chip->base = plat_chip_data->gpio_out_base;
	419	gpio_chip->ngpio = plat_chip_data->num_gpios;
	420
	421	gpio_chip = &(chip->chip_in);
	422	gpio_chip->label = "htcpld-in";
58383c78	423	gpio_chip->parent = dev;
6048a3dd CM	424	gpio_chip->owner = THIS_MODULE;
	425	gpio_chip->get = htcpld_chip_get;
	426	gpio_chip->set = NULL;
	427	gpio_chip->direction_input = htcpld_direction_input;
	428	gpio_chip->direction_output = NULL;
	429	gpio_chip->to_irq = htcpld_chip_to_irq;
	430	gpio_chip->base = plat_chip_data->gpio_in_base;
	431	gpio_chip->ngpio = plat_chip_data->num_gpios;
	432
	433	/* Add the GPIO chips */
ed1c9b3c	434	ret = gpiochip_add_data(&(chip->chip_out), chip);
6048a3dd CM	435	if (ret) {
	436	dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n",
	437	plat_chip_data->addr, ret);
	438	return ret;
	439	}
	440
ed1c9b3c	441	ret = gpiochip_add_data(&(chip->chip_in), chip);
6048a3dd	442	if (ret) {
6048a3dd CM	443	dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
6048a3dd CM	444	plat_chip_data->addr, ret);
88d5e520	445	gpiochip_remove(&(chip->chip_out));
6048a3dd CM	446	return ret;
	447	}
	448
	449	return 0;
	450	}
	451
f791be49	452	static int htcpld_setup_chips(struct platform_device *pdev)
6048a3dd CM	453	{
	454	struct htcpld_data *htcpld;
	455	struct device *dev = &pdev->dev;
	456	struct htcpld_core_platform_data *pdata;
	457	int i;
	458
	459	/* Get the platform and driver data */
334a41ce	460	pdata = dev_get_platdata(dev);
6048a3dd CM	461	htcpld = platform_get_drvdata(pdev);
	462
	463	/* Setup each chip's output GPIOs */
	464	htcpld->nchips = pdata->num_chip;
a86854d0 KC	465	htcpld->chip = devm_kcalloc(dev,
	466	htcpld->nchips,
	467	sizeof(struct htcpld_chip),
2b0b5e2d	468	GFP_KERNEL);
2e4d5494	469	if (!htcpld->chip)
6048a3dd	470	return -ENOMEM;
6048a3dd CM	471
	472	/* Add the chips as best we can */
	473	for (i = 0; i < htcpld->nchips; i++) {
	474	int ret;
	475
	476	/* Setup the HTCPLD chips */
	477	htcpld->chip[i].reset = pdata->chip[i].reset;
	478	htcpld->chip[i].cache_out = pdata->chip[i].reset;
	479	htcpld->chip[i].cache_in = 0;
	480	htcpld->chip[i].dev = dev;
	481	htcpld->chip[i].irq_start = pdata->chip[i].irq_base;
	482	htcpld->chip[i].nirqs = pdata->chip[i].num_irqs;
	483
	484	INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni);
	485	spin_lock_init(&(htcpld->chip[i].lock));
	486
	487	/* Setup the interrupts for the chip */
	488	if (htcpld->chained_irq) {
	489	ret = htcpld_setup_chip_irq(pdev, i);
	490	if (ret)
	491	continue;
	492	}
	493
	494	/* Register the chip with I2C */
	495	ret = htcpld_register_chip_i2c(pdev, i);
	496	if (ret)
	497	continue;
	498
	499
	500	/* Register the chips with the GPIO subsystem */
	501	ret = htcpld_register_chip_gpio(pdev, i);
	502	if (ret) {
	503	/* Unregister the chip from i2c and continue */
	504	htcpld_unregister_chip_i2c(pdev, i);
	505	continue;
	506	}
	507
	508	dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr);
	509	}
	510
	511	return 0;
	512	}
	513
f791be49	514	static int htcpld_core_probe(struct platform_device *pdev)
6048a3dd CM	515	{
	516	struct htcpld_data *htcpld;
	517	struct device *dev = &pdev->dev;
	518	struct htcpld_core_platform_data *pdata;
	519	struct resource *res;
	520	int ret = 0;
	521
	522	if (!dev)
	523	return -ENODEV;
	524
334a41ce	525	pdata = dev_get_platdata(dev);
6048a3dd CM	526	if (!pdata) {
	527	dev_warn(dev, "Platform data not found for htcpld core!\n");
	528	return -ENXIO;
	529	}
	530
2b0b5e2d	531	htcpld = devm_kzalloc(dev, sizeof(struct htcpld_data), GFP_KERNEL);
6048a3dd CM	532	if (!htcpld)
	533	return -ENOMEM;
	534
	535	/* Find chained irq */
6048a3dd CM	536	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	537	if (res) {
	538	int flags;
	539	htcpld->chained_irq = res->start;
	540
	541	/* Setup the chained interrupt handler */
cea2cc73 FE	542	flags = IRQF_TRIGGER_FALLING \| IRQF_TRIGGER_RISING \|
cea2cc73 FE	543	IRQF_ONESHOT;
6048a3dd CM	544	ret = request_threaded_irq(htcpld->chained_irq,
	545	NULL, htcpld_handler,
	546	flags, pdev->name, htcpld);
	547	if (ret) {
	548	dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret);
2b0b5e2d	549	return ret;
6048a3dd CM	550	} else
	551	device_init_wakeup(dev, 0);
	552	}
	553
	554	/* Set the driver data */
	555	platform_set_drvdata(pdev, htcpld);
	556
	557	/* Setup the htcpld chips */
	558	ret = htcpld_setup_chips(pdev);
	559	if (ret)
2b0b5e2d	560	return ret;
6048a3dd CM	561
	562	/* Request the GPIO(s) for the int reset and set them up */
	563	if (pdata->int_reset_gpio_hi) {
	564	ret = gpio_request(pdata->int_reset_gpio_hi, "htcpld-core");
	565	if (ret) {
	566	/*
	567	* If it failed, that sucks, but we can probably
	568	* continue on without it.
	569	*/
	570	dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
	571	htcpld->int_reset_gpio_hi = 0;
	572	} else {
	573	htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi;
	574	gpio_set_value(htcpld->int_reset_gpio_hi, 1);
	575	}
	576	}
	577
	578	if (pdata->int_reset_gpio_lo) {
	579	ret = gpio_request(pdata->int_reset_gpio_lo, "htcpld-core");
	580	if (ret) {
	581	/*
	582	* If it failed, that sucks, but we can probably
	583	* continue on without it.
	584	*/
	585	dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
	586	htcpld->int_reset_gpio_lo = 0;
	587	} else {
	588	htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo;
	589	gpio_set_value(htcpld->int_reset_gpio_lo, 0);
	590	}
	591	}
	592
	593	dev_info(dev, "Initialized successfully\n");
	594	return 0;
6048a3dd CM	595	}
	596
	597	/* The I2C Driver -- used internally */
	598	static const struct i2c_device_id htcpld_chip_id[] = {
	599	{ "htcpld-chip", 0 },
	600	{ }
	601	};
6048a3dd CM	602
	603	static struct i2c_driver htcpld_chip_driver = {
	604	.driver = {
	605	.name = "htcpld-chip",
	606	},
	607	.id_table = htcpld_chip_id,
	608	};
	609
	610	/* The Core Driver */
	611	static struct platform_driver htcpld_core_driver = {
	612	.driver = {
	613	.name = "i2c-htcpld",
	614	},
	615	};
	616
	617	static int __init htcpld_core_init(void)
	618	{
	619	int ret;
	620
	621	/* Register the I2C Chip driver */
	622	ret = i2c_add_driver(&htcpld_chip_driver);
	623	if (ret)
	624	return ret;
	625
	626	/* Probe for our chips */
	627	return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe);
	628	}
11165223	629	device_initcall(htcpld_core_init);