i2c-htcpld: Add the HTCPLD driver

This change introduces a driver for the HTC PLD chip found on some smartphones, such as the HTC Wizard and HTC Herald. It works through the I2C bus and acts as a GPIO extender. Specifically:

* it can have several sub-devices, each with its own I2C address
* Each sub-device provides 8 output and 8 input pins
* The chip attaches to one GPIO to signal when any of the input GPIOs change -- at which point all chips must be scanned for changes

This driver implements the GPIOs throught the kernel's GPIO and IRQ framework. This allows any GPIO-servicing drivers to operate on htcpld pins, such as the gpio-keys and gpio-leds drivers.

drivers/mfd/htc-i2cpld.c new file +40 -0

+	struct htcpld_data *htcpld;
+	struct device *dev = &pdev->dev;
+	struct htcpld_core_platform_data *pdata;
+	struct resource *res;
+	int i, ret = 0;
+	unsigned int irq, irq_end;
+
+	if (!dev)
+		return -ENODEV;
+
+	pdata = dev->platform_data;
+	if (!pdata) {
+		printk(KERN_ERR "Platform data not found for htcpld core!\n");
+		return -ENXIO;
+	}
+
+	htcpld = kzalloc(sizeof(struct htcpld_data), GFP_KERNEL);
+	if (!htcpld)
+		return -ENOMEM;
+
+	/* Find chained irq */
+	ret = -EINVAL;
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (res)
+		htcpld->chained_irq = res->start;
+
+	platform_set_drvdata(pdev, htcpld);
+
+	htcpld->int_reset_gpio_hi = pdata->int_reset_gpio_hi;
+	htcpld->int_reset_gpio_lo = pdata->int_reset_gpio_lo;
+
+	/* Setup each chip's output GPIOs */
+	htcpld->nchips = pdata->num_chip;
+	htcpld->chip = kzalloc(sizeof(struct htcpld_chip) * htcpld->nchips, GFP_KERNEL);
+	if (!htcpld->chip) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	for (i = 0; i < htcpld->nchips; i++) {

drivers/mfd/htc-i2cpld.c new file +18 -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 IRQs */
+		if (htcpld->chained_irq) {
+			int error = 0, flags;
+
+			/* Setup irq handlers */
+			irq_end = htcpld->chip[i].irq_start + htcpld->chip[i].nirqs;
+			for (irq = htcpld->chip[i].irq_start; irq < irq_end; irq++) {
+				set_irq_chip(irq, &htcpld_muxed_chip);
+				set_irq_chip_data(irq, &htcpld->chip[i]);
+				set_irq_handler(irq, handle_simple_irq);
+				set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);

Hi Cory,

late review, sorry about that...

The driver looks fine to me, but I get 23 checkpatch warnings and 5 errors for it.
Could you please fix them, keeping in mind that I'm fine with printk/dev_* strings being more than 80 chars.

A couple of additional comments:

?cpld? ??

Please use pr_* instead. It seems you're using it already, so let's be consistent.

This routine is fairly big, and could be more readable by calling some subroutines. The chips initialisation part could be extracted out for example.

Shouldnt it be: htcpld->chip[i].cache_in = 0; instead ?

You could have a nicer indentation here:
                       error = request_threaded_irq(htcpld->chained_irq, NULL, htcpld_handler, flags, pdev->name, htcpld);

This change introduces a driver for the HTC PLD chip found on some smartphones, such as the HTC Wizard and HTC Herald. It works through the I2C bus and acts as a GPIO extender. Specifically:

* it can have several sub-devices, each with its own I2C address
* Each sub-device provides 8 output and 8 input pins
* The chip attaches to one GPIO to signal when any of the input GPIOs change -- at which point all chips must be scanned for changes

This driver implements the GPIOs throught the kernel's GPIO and IRQ framework. This allows any GPIO-servicing drivers to operate on htcpld pins, such as the gpio-keys and gpio-leds drivers.

Signed-off-by Cory Maccarrone <[email protected]>

---
 drivers/mfd/Kconfig      |    9 +
 drivers/mfd/Makefile     |    1 +
 drivers/mfd/htc-i2cpld.c |  698 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/htcpld.h   |   24 ++
 4 files changed, 732 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/htc-i2cpld.c
 create mode 100644 include/linux/htcpld.h

Differences from v2 to v3 include various cleanups, including splitting out the various parts of the probe() function into subfunctions for readability and fixing checkpatch errors.

drivers/mfd/Kconfig +9 -0

index 8782978..0dec97c 100644
@@ -68,6 +68,15 @@ config HTC_PASIC3
 	  HTC Magician devices, respectively. Actual functionality is
 	  handled by the leds-pasic3 and ds1wm drivers.
 
+config HTC_I2CPLD
+	bool "HTC I2C PLD chip support"
+	depends on I2C
+	help
+	  If you say yes here you get support for the supposed CPLD
+	  found on omap850 HTC devices like the HTC Wizard and HTC Herald.
+	  This device provides input and output GPIOs through an I2C
+	  interface to one or more sub-chips.
+
 config UCB1400_CORE
 	tristate "Philips UCB1400 Core driver"
 	depends on AC97_BUS

drivers/mfd/Makefile +1 -0

index ca2f2c4..c7a295a 100644
@@ -8,6 +8,7 @@ obj-$(CONFIG_MFD_SH_MOBILE_SDHI)		+= sh_mobile_sdhi.o
 
 obj-$(CONFIG_HTC_EGPIO)		+= htc-egpio.o
 obj-$(CONFIG_HTC_PASIC3)	+= htc-pasic3.o
+obj-$(CONFIG_HTC_I2CPLD)	+= htc-i2cpld.o
 
 obj-$(CONFIG_MFD_DM355EVM_MSP)	+= dm355evm_msp.o
 

drivers/mfd/htc-i2cpld.c new file +698 -0

new file mode 100644
index 0000000..7a92e54
@@ -0,0 +1,698 @@
+/*
+ *  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 <[email protected]>
+ *
+ *  Based on work done in the linwizard project
+ *  Copyright (C) 2008-2009 Angelo Arrifano <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.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>
+
+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;
+
+	/*
+	 * 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(unsigned int irq)
+{
+	struct htcpld_chip *chip = get_irq_chip_data(irq);
+	chip->irqs_enabled &= ~(1 << (irq - chip->irq_start));
+	pr_debug("HTCPLD mask %d %04x\n", irq, chip->irqs_enabled);
+}
+static void htcpld_unmask(unsigned int irq)
+{
+	struct htcpld_chip *chip = get_irq_chip_data(irq);
+	chip->irqs_enabled |= 1 << (irq - chip->irq_start);
+	pr_debug("HTCPLD unmask %d %04x\n", irq, chip->irqs_enabled);
+}
+
+static int htcpld_set_type(unsigned int irq, unsigned int flags)
+{
+	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;
+
+	irq_desc[irq].status &= ~IRQ_TYPE_SENSE_MASK;
+	irq_desc[irq].status |= flags;
+
+	return 0;
+}
+
+static struct irq_chip htcpld_muxed_chip = {
+	.name     = "htcpld",
+	.mask     = htcpld_mask,
+	.unmask   = htcpld_unmask,
+	.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;
+	struct irq_desc *desc;
+
+	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;
+			int flags;
+
+			irq = chip->irq_start + irqpin;
+			desc = irq_to_desc(irq);
+			flags = desc->status;
+
+			/* 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 && (flags & IRQ_TYPE_EDGE_RISING)) ||
+			    (oldb && !newb && (flags & IRQ_TYPE_EDGE_FALLING))) {
+				pr_debug("fire IRQ %d\n", irqpin);
+				desc->handle_irq(irq, desc);
+			}
+		}
+	}
+
+	/*
+	 * 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.
+ */
+void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+	struct i2c_client *client;
+	struct htcpld_chip *chip_data;
+	unsigned long flags;
+
+	chip_data = container_of(chip, struct htcpld_chip, chip_out);
+	if (!chip_data)
+		return;
+
+	client = chip_data->client;
+	if (client == NULL)
+		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));
+}
+
+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);
+}
+
+int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct htcpld_chip *chip_data;
+	int val = 0;
+	int is_input = 0;
+
+	/* Try out first */
+	chip_data = container_of(chip, struct htcpld_chip, chip_out);
+	if (!chip_data) {
+		/* Try in */
+		is_input = 1;
+		chip_data = container_of(chip, struct htcpld_chip, chip_in);
+		if (!chip_data)
+			return -EINVAL;
+	}
+
+	/* Determine if this is an input or output GPIO */
+	if (!is_input)
+		/* Use the output cache */
+		val = (chip_data->cache_out >> offset) & 1;
+	else
+		/* Use the input cache */
+		val = (chip_data->cache_in >> offset) & 1;
+
+	if (val)
+		return 1;
+	else
+		return 0;
+}
+
+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;
+}
+
+int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct htcpld_chip *chip_data;
+
+	chip_data = container_of(chip, struct htcpld_chip, chip_in);
+
+	if (offset < chip_data->nirqs)
+		return chip_data->irq_start + offset;
+	else
+		return -EINVAL;
+}
+
+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 __devinit htcpld_setup_chip_irq(
+		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;
+	unsigned int irq, irq_end;
+	int ret = 0;
+
+	/* Get the platform and driver data */
+	pdata = dev->platform_data;
+	htcpld = platform_get_drvdata(pdev);
+	chip = &htcpld->chip[chip_index];
+	plat_chip_data = &pdata->chip[chip_index];
+
+	/* Setup irq handlers */
+	irq_end = chip->irq_start + chip->nirqs;
+	for (irq = chip->irq_start; irq < irq_end; irq++) {
+		set_irq_chip(irq, &htcpld_muxed_chip);
+		set_irq_chip_data(irq, chip);
+		set_irq_handler(irq, handle_simple_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+	}
+
+	return ret;
+}
+
+static int __devinit 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->platform_data;
+	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 == NULL) {
+		/* 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%d", 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 __devinit 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];
+
+	if (chip->client)
+		i2c_unregister_device(chip->client);
+}
+
+static int __devinit 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->platform_data;
+	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->dev             = 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->dev             = 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(&(chip->chip_out));
+	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(&(chip->chip_in));
+	if (ret) {
+		int error;
+
+		dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
+			 plat_chip_data->addr, ret);
+
+		error = gpiochip_remove(&(chip->chip_out));
+		if (error)
+			dev_warn(dev, "Error while trying to unregister gpio chip: %d\n", error);
+
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __devinit 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->platform_data;
+	htcpld = platform_get_drvdata(pdev);
+
+	/* Setup each chip's output GPIOs */
+	htcpld->nchips = pdata->num_chip;
+	htcpld->chip = kzalloc(sizeof(struct htcpld_chip) * htcpld->nchips,
+			       GFP_KERNEL);
+	if (!htcpld->chip) {
+		dev_warn(dev, "Unable to allocate memory for chips\n");
+		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 __devinit 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->platform_data;
+	if (!pdata) {
+		dev_warn(dev, "Platform data not found for htcpld core!\n");
+		return -ENXIO;
+	}
+
+	htcpld = kzalloc(sizeof(struct htcpld_data), GFP_KERNEL);
+	if (!htcpld)
+		return -ENOMEM;
+
+	/* Find chained irq */
+	ret = -EINVAL;
+	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;
+		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);
+			goto fail;
+		} 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)
+		goto fail;
+
+	/* 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;
+
+fail:
+	kfree(htcpld);
+	return ret;
+}
+
+/* The I2C Driver -- used internally */
+static const struct i2c_device_id htcpld_chip_id[] = {
+	{ "htcpld-chip", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, htcpld_chip_id);
+
+
+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);
+}
+
+static void __exit htcpld_core_exit(void)
+{
+	i2c_del_driver(&htcpld_chip_driver);
+	platform_driver_unregister(&htcpld_core_driver);
+}
+
+module_init(htcpld_core_init);
+module_exit(htcpld_core_exit);
+
+MODULE_AUTHOR("Cory Maccarrone <[email protected]>");
+MODULE_DESCRIPTION("I2C HTC PLD Driver");
+MODULE_LICENSE("GPL");
+

include/linux/htcpld.h new file +24 -0

new file mode 100644
index 0000000..ab3f6cb
@@ -0,0 +1,24 @@
+#ifndef __LINUX_HTCPLD_H
+#define __LINUX_HTCPLD_H
+
+struct htcpld_chip_platform_data {
+	unsigned int addr;
+	unsigned int reset;
+	unsigned int num_gpios;
+	unsigned int gpio_out_base;
+	unsigned int gpio_in_base;
+	unsigned int irq_base;
+	unsigned int num_irqs;
+};
+
+struct htcpld_core_platform_data {
+	unsigned int                      int_reset_gpio_hi;
+	unsigned int                      int_reset_gpio_lo;
+	unsigned int                      i2c_adapter_id;
+
+	struct htcpld_chip_platform_data  *chip;
+	unsigned int                      num_chip;
+};
+
+#endif /* __LINUX_HTCPLD_H */
+

Signature · 1 line

1.6.3.3

Hi Cory,

Quoted 12 lines · Cory Maccarrone

This change introduces a driver for the HTC PLD chip found on some smartphones, such as the HTC Wizard and HTC Herald. It works through the I2C bus and acts as a GPIO extender. Specifically:

* it can have several sub-devices, each with its own I2C address
* Each sub-device provides 8 output and 8 input pins
* The chip attaches to one GPIO to signal when any of the input GPIOs change -- at which point all chips must be scanned for changes

Quoted 4 lines

This driver implements the GPIOs throught the kernel's GPIO and IRQ framework. This allows any GPIO-servicing drivers to operate on htcpld pins, such as the gpio-keys and gpio-leds drivers.

I applied this patch, thanks a lot.
In the future, I'd like to see the GPIO handling from this patch moved to drivers/gpio. Could you please look at that ?

Cheers,
Samuel.

Quoted 783 lines

Signed-off-by Cory Maccarrone <[email protected]>

---
 drivers/mfd/Kconfig      |    9 +
 drivers/mfd/Makefile     |    1 +
 drivers/mfd/htc-i2cpld.c |  698 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/htcpld.h   |   24 ++
 4 files changed, 732 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/htc-i2cpld.c
 create mode 100644 include/linux/htcpld.h

Differences from v2 to v3 include various cleanups, including splitting out the various parts of the probe() function into subfunctions for readability and fixing checkpatch errors.

drivers/mfd/Kconfig +9 -0

index 8782978..0dec97c 100644
@@ -68,6 +68,15 @@ config HTC_PASIC3
 	  HTC Magician devices, respectively. Actual functionality is
 	  handled by the leds-pasic3 and ds1wm drivers.
 
+config HTC_I2CPLD
+	bool "HTC I2C PLD chip support"
+	depends on I2C
+	help
+	  If you say yes here you get support for the supposed CPLD
+	  found on omap850 HTC devices like the HTC Wizard and HTC Herald.
+	  This device provides input and output GPIOs through an I2C
+	  interface to one or more sub-chips.
+
 config UCB1400_CORE
 	tristate "Philips UCB1400 Core driver"
 	depends on AC97_BUS

drivers/mfd/Makefile +1 -0

index ca2f2c4..c7a295a 100644
@@ -8,6 +8,7 @@ obj-$(CONFIG_MFD_SH_MOBILE_SDHI)		+= sh_mobile_sdhi.o
 
 obj-$(CONFIG_HTC_EGPIO)		+= htc-egpio.o
 obj-$(CONFIG_HTC_PASIC3)	+= htc-pasic3.o
+obj-$(CONFIG_HTC_I2CPLD)	+= htc-i2cpld.o
 
 obj-$(CONFIG_MFD_DM355EVM_MSP)	+= dm355evm_msp.o
 

drivers/mfd/htc-i2cpld.c new file +698 -0

new file mode 100644
index 0000000..7a92e54
@@ -0,0 +1,698 @@
+/*
+ *  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 <[email protected]>
+ *
+ *  Based on work done in the linwizard project
+ *  Copyright (C) 2008-2009 Angelo Arrifano <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.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>
+
+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;
+
+	/*
+	 * 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(unsigned int irq)
+{
+	struct htcpld_chip *chip = get_irq_chip_data(irq);
+	chip->irqs_enabled &= ~(1 << (irq - chip->irq_start));
+	pr_debug("HTCPLD mask %d %04x\n", irq, chip->irqs_enabled);
+}
+static void htcpld_unmask(unsigned int irq)
+{
+	struct htcpld_chip *chip = get_irq_chip_data(irq);
+	chip->irqs_enabled |= 1 << (irq - chip->irq_start);
+	pr_debug("HTCPLD unmask %d %04x\n", irq, chip->irqs_enabled);
+}
+
+static int htcpld_set_type(unsigned int irq, unsigned int flags)
+{
+	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;
+
+	irq_desc[irq].status &= ~IRQ_TYPE_SENSE_MASK;
+	irq_desc[irq].status |= flags;
+
+	return 0;
+}
+
+static struct irq_chip htcpld_muxed_chip = {
+	.name     = "htcpld",
+	.mask     = htcpld_mask,
+	.unmask   = htcpld_unmask,
+	.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;
+	struct irq_desc *desc;
+
+	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;
+			int flags;
+
+			irq = chip->irq_start + irqpin;
+			desc = irq_to_desc(irq);
+			flags = desc->status;
+
+			/* 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 && (flags & IRQ_TYPE_EDGE_RISING)) ||
+			    (oldb && !newb && (flags & IRQ_TYPE_EDGE_FALLING))) {
+				pr_debug("fire IRQ %d\n", irqpin);
+				desc->handle_irq(irq, desc);
+			}
+		}
+	}
+
+	/*
+	 * 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.
+ */
+void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+	struct i2c_client *client;
+	struct htcpld_chip *chip_data;
+	unsigned long flags;
+
+	chip_data = container_of(chip, struct htcpld_chip, chip_out);
+	if (!chip_data)
+		return;
+
+	client = chip_data->client;
+	if (client == NULL)
+		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));
+}
+
+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);
+}
+
+int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct htcpld_chip *chip_data;
+	int val = 0;
+	int is_input = 0;
+
+	/* Try out first */
+	chip_data = container_of(chip, struct htcpld_chip, chip_out);
+	if (!chip_data) {
+		/* Try in */
+		is_input = 1;
+		chip_data = container_of(chip, struct htcpld_chip, chip_in);
+		if (!chip_data)
+			return -EINVAL;
+	}
+
+	/* Determine if this is an input or output GPIO */
+	if (!is_input)
+		/* Use the output cache */
+		val = (chip_data->cache_out >> offset) & 1;
+	else
+		/* Use the input cache */
+		val = (chip_data->cache_in >> offset) & 1;
+
+	if (val)
+		return 1;
+	else
+		return 0;
+}
+
+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;
+}
+
+int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct htcpld_chip *chip_data;
+
+	chip_data = container_of(chip, struct htcpld_chip, chip_in);
+
+	if (offset < chip_data->nirqs)
+		return chip_data->irq_start + offset;
+	else
+		return -EINVAL;
+}
+
+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 __devinit htcpld_setup_chip_irq(
+		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;
+	unsigned int irq, irq_end;
+	int ret = 0;
+
+	/* Get the platform and driver data */
+	pdata = dev->platform_data;
+	htcpld = platform_get_drvdata(pdev);
+	chip = &htcpld->chip[chip_index];
+	plat_chip_data = &pdata->chip[chip_index];
+
+	/* Setup irq handlers */
+	irq_end = chip->irq_start + chip->nirqs;
+	for (irq = chip->irq_start; irq < irq_end; irq++) {
+		set_irq_chip(irq, &htcpld_muxed_chip);
+		set_irq_chip_data(irq, chip);
+		set_irq_handler(irq, handle_simple_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+	}
+
+	return ret;
+}
+
+static int __devinit 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->platform_data;
+	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 == NULL) {
+		/* 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%d", 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 __devinit 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];
+
+	if (chip->client)
+		i2c_unregister_device(chip->client);
+}
+
+static int __devinit 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->platform_data;
+	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->dev             = 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->dev             = 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(&(chip->chip_out));
+	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(&(chip->chip_in));
+	if (ret) {
+		int error;
+
+		dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
+			 plat_chip_data->addr, ret);
+
+		error = gpiochip_remove(&(chip->chip_out));
+		if (error)
+			dev_warn(dev, "Error while trying to unregister gpio chip: %d\n", error);
+
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __devinit 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->platform_data;
+	htcpld = platform_get_drvdata(pdev);
+
+	/* Setup each chip's output GPIOs */
+	htcpld->nchips = pdata->num_chip;
+	htcpld->chip = kzalloc(sizeof(struct htcpld_chip) * htcpld->nchips,
+			       GFP_KERNEL);
+	if (!htcpld->chip) {
+		dev_warn(dev, "Unable to allocate memory for chips\n");
+		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 __devinit 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->platform_data;
+	if (!pdata) {
+		dev_warn(dev, "Platform data not found for htcpld core!\n");
+		return -ENXIO;
+	}
+
+	htcpld = kzalloc(sizeof(struct htcpld_data), GFP_KERNEL);
+	if (!htcpld)
+		return -ENOMEM;
+
+	/* Find chained irq */
+	ret = -EINVAL;
+	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;
+		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);
+			goto fail;
+		} 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)
+		goto fail;
+
+	/* 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;
+
+fail:
+	kfree(htcpld);
+	return ret;
+}
+
+/* The I2C Driver -- used internally */
+static const struct i2c_device_id htcpld_chip_id[] = {
+	{ "htcpld-chip", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, htcpld_chip_id);
+
+
+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);
+}
+
+static void __exit htcpld_core_exit(void)
+{
+	i2c_del_driver(&htcpld_chip_driver);
+	platform_driver_unregister(&htcpld_core_driver);
+}
+
+module_init(htcpld_core_init);
+module_exit(htcpld_core_exit);
+
+MODULE_AUTHOR("Cory Maccarrone <[email protected]>");
+MODULE_DESCRIPTION("I2C HTC PLD Driver");
+MODULE_LICENSE("GPL");
+

include/linux/htcpld.h new file +24 -0

new file mode 100644
index 0000000..ab3f6cb
@@ -0,0 +1,24 @@
+#ifndef __LINUX_HTCPLD_H
+#define __LINUX_HTCPLD_H
+
+struct htcpld_chip_platform_data {
+	unsigned int addr;
+	unsigned int reset;
+	unsigned int num_gpios;
+	unsigned int gpio_out_base;
+	unsigned int gpio_in_base;
+	unsigned int irq_base;
+	unsigned int num_irqs;
+};
+
+struct htcpld_core_platform_data {
+	unsigned int                      int_reset_gpio_hi;
+	unsigned int                      int_reset_gpio_lo;
+	unsigned int                      i2c_adapter_id;
+
+	struct htcpld_chip_platform_data  *chip;
+	unsigned int                      num_chip;
+};
+
+#endif /* __LINUX_HTCPLD_H */
+

Signature · 1 line

1.6.3.3

Signature · 2 lines

Intel Open Source Technology Centre
http://oss.intel.com/

Quoted 5 lines · Samuel Ortiz

Hi Cory,

I applied this patch, thanks a lot.
In the future, I'd like to see the GPIO handling from this patch moved to drivers/gpio. Could you please look at that ?

I forgot to add that I also made it build on non ARM patforms. This line:
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
became:
#ifdef CONFIG_ARM
               set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); #else
               set_irq_probe(irq);
#endif

Quoted 6 lines · Samuel Ortiz

Quoted 5 lines · Samuel Ortiz

Hi Cory,

I applied this patch, thanks a lot.
In the future, I'd like to see the GPIO handling from this patch moved to drivers/gpio. Could you please look at that ?

Absolutely, thanks for applying it! I'll send out a follow-on patch as soon as I've got that change.

Quoted 9 lines

I forgot to add that I also made it build on non ARM patforms. This line:
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
became:
#ifdef CONFIG_ARM
               set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); #else
               set_irq_probe(irq);
#endif

Ah, cool, thanks!

- Cory

2) Kconfig: we need to depend on I2C=y, to avoid the problematic case of having I2C_CORE=m and HTC_I2CPLD=y

Hi Samuel,

Quoted 2 lines · Samuel Ortiz

2) Kconfig: we need to depend on I2C=y, to avoid the problematic case of having I2C_CORE=m and HTC_I2CPLD=y

??

There is no config option named I2C_CORE. The main option for I2C is, well, I2C,

and if you depend on I2C, then you can't be built into the kernel if I2C is built as a module.

What exact problem are you trying to solve?

Signature · 1 line

Jean Delvare

Hi Jean,

Quoted 10 lines · Jean Delvare

Hi Samuel,

Quoted 2 lines · Samuel Ortiz

2) Kconfig: we need to depend on I2C=y, to avoid the problematic case of having I2C_CORE=m and HTC_I2CPLD=y

??

There is no config option named I2C_CORE. The main option for I2C is, well, I2C,

Sorry, I meant I2C, not I2C_CORE.

Quoted 2 lines

and if you depend on I2C, then you can't be built into the kernel if I2C is built as a module.

I have:

drivers/mfd/Kconfig:
config HTC_I2CPLD
bool "HTC I2C PLD chip support"
depends on I2C

Then make menuconfig allows me to build a .config with

CONFIG_I2C=m and CONFIG_HTC_I2CPLD=y

and that obviously fails to build. If I'm a bool depending on I2C, it has to be a built-in I2C.

Quoted 27 lines · Samuel Ortiz

Hi Jean,

Quoted 10 lines · Jean Delvare

Hi Samuel,

Quoted 2 lines · Samuel Ortiz

2) Kconfig: we need to depend on I2C=y, to avoid the problematic case of having I2C_CORE=m and HTC_I2CPLD=y

??

There is no config option named I2C_CORE. The main option for I2C is, well, I2C,

Sorry, I meant I2C, not I2C_CORE.

Quoted 2 lines

and if you depend on I2C, then you can't be built into the kernel if I2C is built as a module.

I have:

drivers/mfd/Kconfig:
config HTC_I2CPLD
      bool "HTC I2C PLD chip support"
      depends on I2C

Then make menuconfig allows me to build a .config with

Quoted 4 lines

CONFIG_I2C=m and CONFIG_HTC_I2CPLD=y

and that obviously fails to build. If I'm a bool depending on I2C, it has to be a built-in I2C.

Ah, my bad, I totally missed that HTC_I2CPLD was a bool. Please just ignore me, sorry for the noise. You are correct, it should depend on I2C=y.

Quoted 28 lines · Jean Delvare

Quoted 27 lines · Samuel Ortiz

Hi Jean,

Quoted 10 lines · Jean Delvare

Hi Samuel,

Quoted 2 lines · Samuel Ortiz

2) Kconfig: we need to depend on I2C=y, to avoid the problematic case of having I2C_CORE=m and HTC_I2CPLD=y

??

There is no config option named I2C_CORE. The main option for I2C is, well, I2C,

Sorry, I meant I2C, not I2C_CORE.

Quoted 2 lines

and if you depend on I2C, then you can't be built into the kernel if I2C is built as a module.

I have:

drivers/mfd/Kconfig:
config HTC_I2CPLD
      bool "HTC I2C PLD chip support"
      depends on I2C

Then make menuconfig allows me to build a .config with

Quoted 9 lines

Quoted 4 lines

CONFIG_I2C=m and CONFIG_HTC_I2CPLD=y

and that obviously fails to build. If I'm a bool depending on I2C, it has to be a built-in I2C.

Ah, my bad, I totally missed that HTC_I2CPLD was a bool. Please just ignore me, sorry for the noise. You are correct, it should depend on I2C=y.

All these changes sound fine to me, thanks for doing that!  Sorry for the compile mess, I'll keep all this in mind for later work.

- Cory