--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TQ-Systems TQMx86 PLD GPIO driver
+ *
+ * Based on vendor driver by:
+ * Vadim V.Vlasov <vvlasov@dev.rtsoft.ru>
+ */
+
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#define TQMX86_NGPIO 8
+#define TQMX86_NGPO 4 /* 0-3 - output */
+#define TQMX86_NGPI 4 /* 4-7 - input */
+#define TQMX86_DIR_INPUT_MASK 0xf0 /* 0-3 - output, 4-7 - input */
+
+#define TQMX86_GPIODD 0 /* GPIO Data Direction Register */
+#define TQMX86_GPIOD 1 /* GPIO Data Register */
+#define TQMX86_GPIIC 3 /* GPI Interrupt Configuration Register */
+#define TQMX86_GPIIS 4 /* GPI Interrupt Status Register */
+
+#define TQMX86_GPII_FALLING BIT(0)
+#define TQMX86_GPII_RISING BIT(1)
+#define TQMX86_GPII_MASK (BIT(0) | BIT(1))
+#define TQMX86_GPII_BITS 2
+
+struct tqmx86_gpio_data {
+ struct gpio_chip chip;
+ struct irq_chip irq_chip;
+ void __iomem *io_base;
+ int irq;
+ raw_spinlock_t spinlock;
+ u8 irq_type[TQMX86_NGPI];
+};
+
+static u8 tqmx86_gpio_read(struct tqmx86_gpio_data *gd, unsigned int reg)
+{
+ return ioread8(gd->io_base + reg);
+}
+
+static void tqmx86_gpio_write(struct tqmx86_gpio_data *gd, u8 val,
+ unsigned int reg)
+{
+ iowrite8(val, gd->io_base + reg);
+}
+
+static int tqmx86_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
+
+ return !!(tqmx86_gpio_read(gpio, TQMX86_GPIOD) & BIT(offset));
+}
+
+static void tqmx86_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
+ unsigned long flags;
+ u8 val;
+
+ raw_spin_lock_irqsave(&gpio->spinlock, flags);
+ val = tqmx86_gpio_read(gpio, TQMX86_GPIOD);
+ if (value)
+ val |= BIT(offset);
+ else
+ val &= ~BIT(offset);
+ tqmx86_gpio_write(gpio, val, TQMX86_GPIOD);
+ raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+}
+
+static int tqmx86_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ /* Direction cannot be changed. Validate is an input. */
+ if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
+ return 0;
+ else
+ return -EINVAL;
+}
+
+static int tqmx86_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset,
+ int value)
+{
+ /* Direction cannot be changed, validate is an output */
+ if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
+ return -EINVAL;
+ else
+ return 0;
+}
+
+static int tqmx86_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ return !!(TQMX86_DIR_INPUT_MASK & BIT(offset));
+}
+
+static void tqmx86_gpio_irq_mask(struct irq_data *data)
+{
+ unsigned int offset = (data->hwirq - TQMX86_NGPO);
+ struct tqmx86_gpio_data *gpio = gpiochip_get_data(
+ irq_data_get_irq_chip_data(data));
+ unsigned long flags;
+ u8 gpiic, mask;
+
+ mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
+
+ raw_spin_lock_irqsave(&gpio->spinlock, flags);
+ gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
+ gpiic &= ~mask;
+ tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
+ raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+}
+
+static void tqmx86_gpio_irq_unmask(struct irq_data *data)
+{
+ unsigned int offset = (data->hwirq - TQMX86_NGPO);
+ struct tqmx86_gpio_data *gpio = gpiochip_get_data(
+ irq_data_get_irq_chip_data(data));
+ unsigned long flags;
+ u8 gpiic, mask;
+
+ mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
+
+ raw_spin_lock_irqsave(&gpio->spinlock, flags);
+ gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
+ gpiic &= ~mask;
+ gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS);
+ tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
+ raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+}
+
+static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ struct tqmx86_gpio_data *gpio = gpiochip_get_data(
+ irq_data_get_irq_chip_data(data));
+ unsigned int offset = (data->hwirq - TQMX86_NGPO);
+ unsigned int edge_type = type & IRQF_TRIGGER_MASK;
+ unsigned long flags;
+ u8 new_type, gpiic;
+
+ switch (edge_type) {
+ case IRQ_TYPE_EDGE_RISING:
+ new_type = TQMX86_GPII_RISING;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ new_type = TQMX86_GPII_FALLING;
+ break;
+ case IRQ_TYPE_EDGE_BOTH:
+ new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING;
+ break;
+ default:
+ return -EINVAL; /* not supported */
+ }
+
+ gpio->irq_type[offset] = new_type;
+
+ raw_spin_lock_irqsave(&gpio->spinlock, flags);
+ gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
+ gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS));
+ gpiic |= new_type << (offset * TQMX86_GPII_BITS);
+ tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
+ raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+
+ return 0;
+}
+
+static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
+{
+ struct gpio_chip *chip = irq_desc_get_handler_data(desc);
+ struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
+ struct irq_chip *irq_chip = irq_desc_get_chip(desc);
+ unsigned long irq_bits;
+ int i = 0, child_irq;
+ u8 irq_status;
+
+ chained_irq_enter(irq_chip, desc);
+
+ irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS);
+ tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
+
+ irq_bits = irq_status;
+ for_each_set_bit(i, &irq_bits, TQMX86_NGPI) {
+ child_irq = irq_find_mapping(gpio->chip.irq.domain,
+ i + TQMX86_NGPO);
+ generic_handle_irq(child_irq);
+ }
+
+ chained_irq_exit(irq_chip, desc);
+}
+
+/* Minimal runtime PM is needed by the IRQ subsystem */
+static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev)
+{
+ return 0;
+}
+
+static int __maybe_unused tqmx86_gpio_runtime_resume(struct device *dev)
+{
+ return 0;
+}
+
+static const struct dev_pm_ops tqmx86_gpio_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend,
+ tqmx86_gpio_runtime_resume, NULL)
+};
+
+static int tqmx86_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct tqmx86_gpio_data *gpio;
+ struct gpio_chip *chip;
+ void __iomem *io_base;
+ struct resource *res;
+ int ret, irq;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "Cannot get I/O\n");
+ return -ENODEV;
+ }
+
+ io_base = devm_ioport_map(&pdev->dev, res->start, resource_size(res));
+ if (!io_base)
+ return -ENOMEM;
+
+ gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+
+ raw_spin_lock_init(&gpio->spinlock);
+ gpio->io_base = io_base;
+
+ tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD);
+
+ platform_set_drvdata(pdev, gpio);
+
+ chip = &gpio->chip;
+ chip->label = "gpio-tqmx86";
+ chip->owner = THIS_MODULE;
+ chip->can_sleep = false;
+ chip->base = -1;
+ chip->direction_input = tqmx86_gpio_direction_input;
+ chip->direction_output = tqmx86_gpio_direction_output;
+ chip->get_direction = tqmx86_gpio_get_direction;
+ chip->get = tqmx86_gpio_get;
+ chip->set = tqmx86_gpio_set;
+ chip->ngpio = TQMX86_NGPIO;
+ chip->irq.need_valid_mask = true;
+ chip->parent = pdev->dev.parent;
+
+ pm_runtime_enable(&pdev->dev);
+
+ ret = devm_gpiochip_add_data(dev, chip, gpio);
+ if (ret) {
+ dev_err(dev, "Could not register GPIO chip\n");
+ goto out_pm_dis;
+ }
+
+ if (irq) {
+ struct irq_chip *irq_chip = &gpio->irq_chip;
+ u8 irq_status;
+
+ irq_chip->name = chip->label;
+ irq_chip->parent_device = &pdev->dev;
+ irq_chip->irq_mask = tqmx86_gpio_irq_mask;
+ irq_chip->irq_unmask = tqmx86_gpio_irq_unmask;
+ irq_chip->irq_set_type = tqmx86_gpio_irq_set_type;
+
+ /* Mask all interrupts */
+ tqmx86_gpio_write(gpio, 0, TQMX86_GPIIC);
+
+ /* Clear all pending interrupts */
+ irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS);
+ tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
+
+ ret = gpiochip_irqchip_add(chip, irq_chip,
+ 0, handle_simple_irq,
+ IRQ_TYPE_EDGE_BOTH);
+ if (ret) {
+ dev_err(dev, "Could not add irq chip\n");
+ goto out_remove;
+ }
+
+ gpiochip_set_chained_irqchip(chip, irq_chip,
+ irq, tqmx86_gpio_irq_handler);
+ }
+
+ /* Only GPIOs 4-7 are valid for interrupts. Clear the others */
+ clear_bit(0, chip->irq.valid_mask);
+ clear_bit(1, chip->irq.valid_mask);
+ clear_bit(2, chip->irq.valid_mask);
+ clear_bit(3, chip->irq.valid_mask);
+
+ dev_info(dev, "GPIO functionality initialized with %d pins\n",
+ chip->ngpio);
+
+ return 0;
+
+out_remove:
+ gpiochip_remove(&gpio->chip);
+out_pm_dis:
+ pm_runtime_disable(&pdev->dev);
+
+ return ret;
+}
+
+static struct platform_driver tqmx86_gpio_driver = {
+ .driver = {
+ .name = "tqmx86-gpio",
+ .pm = &tqmx86_gpio_dev_pm_ops,
+ },
+ .probe = tqmx86_gpio_probe,
+};
+
+module_platform_driver(tqmx86_gpio_driver);
+
+MODULE_DESCRIPTION("TQMx86 PLD GPIO Driver");
+MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:tqmx86-gpio");
projects / platform / kernel / linux-rpi.git / commitdiff