1 files changed, 627 insertions, 0 deletions

diff --git a/drivers/mfd/htc-i2cpld.c b/drivers/mfd/htc-i2cpld.c
new file mode 100644
index 000000000..b45b1346a
--- /dev/null
+++ b/drivers/mfd/htc-i2cpld.c
@@ -0,0 +1,627 @@
+// 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/driver.h>
+#include <linux/gpio/machine.h>
+#include <linux/gpio/consumer.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;
+	struct gpio_desc   *int_reset_gpio_hi;
+	struct gpio_desc   *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)
+		gpiod_set_value(htcpld->int_reset_gpio_hi, 1);
+	if (htcpld->int_reset_gpio_lo)
+		gpiod_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);
+		i2c_put_adapter(adapter);
+		return -EINVAL;
+	}
+
+	memset(&info, 0, sizeof(struct i2c_board_info));
+	info.addr = plat_chip_data->addr;
+	strscpy(info.type, "htcpld-chip", I2C_NAME_SIZE);
+	info.platform_data = chip;
+
+	/* Add the I2C device.  This calls the probe() function. */
+	client = i2c_new_client_device(adapter, &info);
+	if (IS_ERR(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);
+		i2c_put_adapter(adapter);
+		return PTR_ERR(client);
+	}
+
+	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 */
+	htcpld->int_reset_gpio_hi = gpiochip_request_own_desc(&htcpld->chip[2].chip_out,
+							      7, "htcpld-core", GPIO_ACTIVE_HIGH,
+							      GPIOD_OUT_HIGH);
+	if (IS_ERR(htcpld->int_reset_gpio_hi)) {
+		/*
+		 * If it failed, that sucks, but we can probably
+		 * continue on without it.
+		 */
+		htcpld->int_reset_gpio_hi = NULL;
+		dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
+	}
+
+	htcpld->int_reset_gpio_lo = gpiochip_request_own_desc(&htcpld->chip[2].chip_out,
+							      0, "htcpld-core", GPIO_ACTIVE_HIGH,
+							      GPIOD_OUT_LOW);
+	if (IS_ERR(htcpld->int_reset_gpio_lo)) {
+		/*
+		 * If it failed, that sucks, but we can probably
+		 * continue on without it.
+		 */
+		htcpld->int_reset_gpio_lo = NULL;
+		dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
+	}
+
+	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);