--- /dev/null
+/*
+ * 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>
+ *
+ * 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)
+{
+ struct irq_desc *d = irq_to_desc(irq);
+
+ if (!d) {
+ pr_err("HTCPLD invalid IRQ: %d\n", irq);
+ return -EINVAL;
+ }
+
+ 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;
+
+ d->status &= ~IRQ_TYPE_SENSE_MASK;
+ d->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);
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+#else
+ set_irq_probe(irq);
+#endif
+ }
+
+ 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 <darkstar6262@gmail.com>");
+MODULE_DESCRIPTION("I2C HTC PLD Driver");
+MODULE_LICENSE("GPL");
+
projects / platform / kernel / kernel-mfld-blackbay.git / commitdiff