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path: root/drivers/gpio/gpio-htc-egpio.c
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Diffstat (limited to 'drivers/gpio/gpio-htc-egpio.c')
-rw-r--r--drivers/gpio/gpio-htc-egpio.c409
1 files changed, 409 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-htc-egpio.c b/drivers/gpio/gpio-htc-egpio.c
new file mode 100644
index 0000000000..a40bd56673
--- /dev/null
+++ b/drivers/gpio/gpio-htc-egpio.c
@@ -0,0 +1,409 @@
+/*
+ * Support for the GPIO/IRQ expander chips present on several HTC phones.
+ * These are implemented in CPLD chips present on the board.
+ *
+ * Copyright (c) 2007 Kevin O'Connor <kevin@koconnor.net>
+ * Copyright (c) 2007 Philipp Zabel <philipp.zabel@gmail.com>
+ *
+ * This file may be distributed under the terms of the GNU GPL license.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/platform_data/gpio-htc-egpio.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/gpio/driver.h>
+
+struct egpio_chip {
+ int reg_start;
+ int cached_values;
+ unsigned long is_out;
+ struct device *dev;
+ struct gpio_chip chip;
+};
+
+struct egpio_info {
+ spinlock_t lock;
+
+ /* iomem info */
+ void __iomem *base_addr;
+ int bus_shift; /* byte shift */
+ int reg_shift; /* bit shift */
+ int reg_mask;
+
+ /* irq info */
+ int ack_register;
+ int ack_write;
+ u16 irqs_enabled;
+ uint irq_start;
+ int nirqs;
+ uint chained_irq;
+
+ /* egpio info */
+ struct egpio_chip *chip;
+ int nchips;
+};
+
+static inline void egpio_writew(u16 value, struct egpio_info *ei, int reg)
+{
+ writew(value, ei->base_addr + (reg << ei->bus_shift));
+}
+
+static inline u16 egpio_readw(struct egpio_info *ei, int reg)
+{
+ return readw(ei->base_addr + (reg << ei->bus_shift));
+}
+
+/*
+ * IRQs
+ */
+
+static inline void ack_irqs(struct egpio_info *ei)
+{
+ egpio_writew(ei->ack_write, ei, ei->ack_register);
+ pr_debug("EGPIO ack - write %x to base+%x\n",
+ ei->ack_write, ei->ack_register << ei->bus_shift);
+}
+
+static void egpio_ack(struct irq_data *data)
+{
+}
+
+/* There does not appear to be a way to proactively mask interrupts
+ * on the egpio chip itself. So, we simply ignore interrupts that
+ * aren't desired. */
+static void egpio_mask(struct irq_data *data)
+{
+ struct egpio_info *ei = irq_data_get_irq_chip_data(data);
+ ei->irqs_enabled &= ~(1 << (data->irq - ei->irq_start));
+ pr_debug("EGPIO mask %d %04x\n", data->irq, ei->irqs_enabled);
+}
+
+static void egpio_unmask(struct irq_data *data)
+{
+ struct egpio_info *ei = irq_data_get_irq_chip_data(data);
+ ei->irqs_enabled |= 1 << (data->irq - ei->irq_start);
+ pr_debug("EGPIO unmask %d %04x\n", data->irq, ei->irqs_enabled);
+}
+
+static struct irq_chip egpio_muxed_chip = {
+ .name = "htc-egpio",
+ .irq_ack = egpio_ack,
+ .irq_mask = egpio_mask,
+ .irq_unmask = egpio_unmask,
+};
+
+static void egpio_handler(struct irq_desc *desc)
+{
+ struct egpio_info *ei = irq_desc_get_handler_data(desc);
+ int irqpin;
+
+ /* Read current pins. */
+ unsigned long readval = egpio_readw(ei, ei->ack_register);
+ pr_debug("IRQ reg: %x\n", (unsigned int)readval);
+ /* Ack/unmask interrupts. */
+ ack_irqs(ei);
+ /* Process all set pins. */
+ readval &= ei->irqs_enabled;
+ for_each_set_bit(irqpin, &readval, ei->nirqs) {
+ /* Run irq handler */
+ pr_debug("got IRQ %d\n", irqpin);
+ generic_handle_irq(ei->irq_start + irqpin);
+ }
+}
+
+static inline int egpio_pos(struct egpio_info *ei, int bit)
+{
+ return bit >> ei->reg_shift;
+}
+
+static inline int egpio_bit(struct egpio_info *ei, int bit)
+{
+ return 1 << (bit & ((1 << ei->reg_shift)-1));
+}
+
+/*
+ * Input pins
+ */
+
+static int egpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct egpio_chip *egpio;
+ struct egpio_info *ei;
+ unsigned bit;
+ int reg;
+ int value;
+
+ pr_debug("egpio_get_value(%d)\n", chip->base + offset);
+
+ egpio = gpiochip_get_data(chip);
+ ei = dev_get_drvdata(egpio->dev);
+ bit = egpio_bit(ei, offset);
+ reg = egpio->reg_start + egpio_pos(ei, offset);
+
+ if (test_bit(offset, &egpio->is_out)) {
+ return !!(egpio->cached_values & (1 << offset));
+ } else {
+ value = egpio_readw(ei, reg);
+ pr_debug("readw(%p + %x) = %x\n",
+ ei->base_addr, reg << ei->bus_shift, value);
+ return !!(value & bit);
+ }
+}
+
+static int egpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct egpio_chip *egpio;
+
+ egpio = gpiochip_get_data(chip);
+ return test_bit(offset, &egpio->is_out) ? -EINVAL : 0;
+}
+
+
+/*
+ * Output pins
+ */
+
+static void egpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ unsigned long flag;
+ struct egpio_chip *egpio;
+ struct egpio_info *ei;
+ int pos;
+ int reg;
+ int shift;
+
+ pr_debug("egpio_set(%s, %d(%d), %d)\n",
+ chip->label, offset, offset+chip->base, value);
+
+ egpio = gpiochip_get_data(chip);
+ ei = dev_get_drvdata(egpio->dev);
+ pos = egpio_pos(ei, offset);
+ reg = egpio->reg_start + pos;
+ shift = pos << ei->reg_shift;
+
+ pr_debug("egpio %s: reg %d = 0x%04x\n", value ? "set" : "clear",
+ reg, (egpio->cached_values >> shift) & ei->reg_mask);
+
+ spin_lock_irqsave(&ei->lock, flag);
+ if (value)
+ egpio->cached_values |= (1 << offset);
+ else
+ egpio->cached_values &= ~(1 << offset);
+ egpio_writew((egpio->cached_values >> shift) & ei->reg_mask, ei, reg);
+ spin_unlock_irqrestore(&ei->lock, flag);
+}
+
+static int egpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct egpio_chip *egpio;
+
+ egpio = gpiochip_get_data(chip);
+ if (test_bit(offset, &egpio->is_out)) {
+ egpio_set(chip, offset, value);
+ return 0;
+ } else {
+ return -EINVAL;
+ }
+}
+
+static int egpio_get_direction(struct gpio_chip *chip, unsigned offset)
+{
+ struct egpio_chip *egpio;
+
+ egpio = gpiochip_get_data(chip);
+
+ if (test_bit(offset, &egpio->is_out))
+ return GPIO_LINE_DIRECTION_OUT;
+
+ return GPIO_LINE_DIRECTION_IN;
+}
+
+static void egpio_write_cache(struct egpio_info *ei)
+{
+ int i;
+ struct egpio_chip *egpio;
+ int shift;
+
+ for (i = 0; i < ei->nchips; i++) {
+ egpio = &(ei->chip[i]);
+ if (!egpio->is_out)
+ continue;
+
+ for (shift = 0; shift < egpio->chip.ngpio;
+ shift += (1<<ei->reg_shift)) {
+
+ int reg = egpio->reg_start + egpio_pos(ei, shift);
+
+ if (!((egpio->is_out >> shift) & ei->reg_mask))
+ continue;
+
+ pr_debug("EGPIO: setting %x to %x, was %x\n", reg,
+ (egpio->cached_values >> shift) & ei->reg_mask,
+ egpio_readw(ei, reg));
+
+ egpio_writew((egpio->cached_values >> shift)
+ & ei->reg_mask, ei, reg);
+ }
+ }
+}
+
+
+/*
+ * Setup
+ */
+
+static int __init egpio_probe(struct platform_device *pdev)
+{
+ struct htc_egpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct resource *res;
+ struct egpio_info *ei;
+ struct gpio_chip *chip;
+ unsigned int irq, irq_end;
+ int i;
+
+ /* Initialize ei data structure. */
+ ei = devm_kzalloc(&pdev->dev, sizeof(*ei), GFP_KERNEL);
+ if (!ei)
+ return -ENOMEM;
+
+ spin_lock_init(&ei->lock);
+
+ /* Find chained irq */
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (res)
+ ei->chained_irq = res->start;
+
+ /* Map egpio chip into virtual address space. */
+ ei->base_addr = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ei->base_addr))
+ return PTR_ERR(ei->base_addr);
+
+ if ((pdata->bus_width != 16) && (pdata->bus_width != 32))
+ return -EINVAL;
+
+ ei->bus_shift = fls(pdata->bus_width - 1) - 3;
+ pr_debug("bus_shift = %d\n", ei->bus_shift);
+
+ if ((pdata->reg_width != 8) && (pdata->reg_width != 16))
+ return -EINVAL;
+
+ ei->reg_shift = fls(pdata->reg_width - 1);
+ pr_debug("reg_shift = %d\n", ei->reg_shift);
+
+ ei->reg_mask = (1 << pdata->reg_width) - 1;
+
+ platform_set_drvdata(pdev, ei);
+
+ ei->nchips = pdata->num_chips;
+ ei->chip = devm_kcalloc(&pdev->dev,
+ ei->nchips, sizeof(struct egpio_chip),
+ GFP_KERNEL);
+ if (!ei->chip)
+ return -ENOMEM;
+
+ for (i = 0; i < ei->nchips; i++) {
+ ei->chip[i].reg_start = pdata->chip[i].reg_start;
+ ei->chip[i].cached_values = pdata->chip[i].initial_values;
+ ei->chip[i].is_out = pdata->chip[i].direction;
+ ei->chip[i].dev = &(pdev->dev);
+ chip = &(ei->chip[i].chip);
+ chip->label = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+ "htc-egpio-%d",
+ i);
+ if (!chip->label)
+ return -ENOMEM;
+
+ chip->parent = &pdev->dev;
+ chip->owner = THIS_MODULE;
+ chip->get = egpio_get;
+ chip->set = egpio_set;
+ chip->direction_input = egpio_direction_input;
+ chip->direction_output = egpio_direction_output;
+ chip->get_direction = egpio_get_direction;
+ chip->base = pdata->chip[i].gpio_base;
+ chip->ngpio = pdata->chip[i].num_gpios;
+
+ gpiochip_add_data(chip, &ei->chip[i]);
+ }
+
+ /* Set initial pin values */
+ egpio_write_cache(ei);
+
+ ei->irq_start = pdata->irq_base;
+ ei->nirqs = pdata->num_irqs;
+ ei->ack_register = pdata->ack_register;
+
+ if (ei->chained_irq) {
+ /* Setup irq handlers */
+ ei->ack_write = 0xFFFF;
+ if (pdata->invert_acks)
+ ei->ack_write = 0;
+ irq_end = ei->irq_start + ei->nirqs;
+ for (irq = ei->irq_start; irq < irq_end; irq++) {
+ irq_set_chip_and_handler(irq, &egpio_muxed_chip,
+ handle_simple_irq);
+ irq_set_chip_data(irq, ei);
+ irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
+ }
+ irq_set_irq_type(ei->chained_irq, IRQ_TYPE_EDGE_RISING);
+ irq_set_chained_handler_and_data(ei->chained_irq,
+ egpio_handler, ei);
+ ack_irqs(ei);
+
+ device_init_wakeup(&pdev->dev, 1);
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int egpio_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct egpio_info *ei = platform_get_drvdata(pdev);
+
+ if (ei->chained_irq && device_may_wakeup(&pdev->dev))
+ enable_irq_wake(ei->chained_irq);
+ return 0;
+}
+
+static int egpio_resume(struct platform_device *pdev)
+{
+ struct egpio_info *ei = platform_get_drvdata(pdev);
+
+ if (ei->chained_irq && device_may_wakeup(&pdev->dev))
+ disable_irq_wake(ei->chained_irq);
+
+ /* Update registers from the cache, in case
+ the CPLD was powered off during suspend */
+ egpio_write_cache(ei);
+ return 0;
+}
+#else
+#define egpio_suspend NULL
+#define egpio_resume NULL
+#endif
+
+
+static struct platform_driver egpio_driver = {
+ .driver = {
+ .name = "htc-egpio",
+ .suppress_bind_attrs = true,
+ },
+ .suspend = egpio_suspend,
+ .resume = egpio_resume,
+};
+
+static int __init egpio_init(void)
+{
+ return platform_driver_probe(&egpio_driver, egpio_probe);
+}
+/* start early for dependencies */
+subsys_initcall(egpio_init);