summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-altera.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/gpio/gpio-altera.c')
-rw-r--r--drivers/gpio/gpio-altera.c354
1 files changed, 354 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-altera.c b/drivers/gpio/gpio-altera.c
new file mode 100644
index 000000000..b7932ecc3
--- /dev/null
+++ b/drivers/gpio/gpio-altera.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2013 Altera Corporation
+ * Based on gpio-mpc8xxx.c
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/gpio/driver.h>
+#include <linux/of_gpio.h> /* For of_mm_gpio_chip */
+#include <linux/platform_device.h>
+
+#define ALTERA_GPIO_MAX_NGPIO 32
+#define ALTERA_GPIO_DATA 0x0
+#define ALTERA_GPIO_DIR 0x4
+#define ALTERA_GPIO_IRQ_MASK 0x8
+#define ALTERA_GPIO_EDGE_CAP 0xc
+
+/**
+* struct altera_gpio_chip
+* @mmchip : memory mapped chip structure.
+* @gpio_lock : synchronization lock so that new irq/set/get requests
+* will be blocked until the current one completes.
+* @interrupt_trigger : specifies the hardware configured IRQ trigger type
+* (rising, falling, both, high)
+* @mapped_irq : kernel mapped irq number.
+* @irq_chip : IRQ chip configuration
+*/
+struct altera_gpio_chip {
+ struct of_mm_gpio_chip mmchip;
+ raw_spinlock_t gpio_lock;
+ int interrupt_trigger;
+ int mapped_irq;
+ struct irq_chip irq_chip;
+};
+
+static void altera_gpio_irq_unmask(struct irq_data *d)
+{
+ struct altera_gpio_chip *altera_gc;
+ struct of_mm_gpio_chip *mm_gc;
+ unsigned long flags;
+ u32 intmask;
+
+ altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
+ mm_gc = &altera_gc->mmchip;
+
+ raw_spin_lock_irqsave(&altera_gc->gpio_lock, flags);
+ intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+ /* Set ALTERA_GPIO_IRQ_MASK bit to unmask */
+ intmask |= BIT(irqd_to_hwirq(d));
+ writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+ raw_spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
+}
+
+static void altera_gpio_irq_mask(struct irq_data *d)
+{
+ struct altera_gpio_chip *altera_gc;
+ struct of_mm_gpio_chip *mm_gc;
+ unsigned long flags;
+ u32 intmask;
+
+ altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
+ mm_gc = &altera_gc->mmchip;
+
+ raw_spin_lock_irqsave(&altera_gc->gpio_lock, flags);
+ intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+ /* Clear ALTERA_GPIO_IRQ_MASK bit to mask */
+ intmask &= ~BIT(irqd_to_hwirq(d));
+ writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+ raw_spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
+}
+
+/*
+ * This controller's IRQ type is synthesized in hardware, so this function
+ * just checks if the requested set_type matches the synthesized IRQ type
+ */
+static int altera_gpio_irq_set_type(struct irq_data *d,
+ unsigned int type)
+{
+ struct altera_gpio_chip *altera_gc;
+
+ altera_gc = gpiochip_get_data(irq_data_get_irq_chip_data(d));
+
+ if (type == IRQ_TYPE_NONE) {
+ irq_set_handler_locked(d, handle_bad_irq);
+ return 0;
+ }
+ if (type == altera_gc->interrupt_trigger) {
+ if (type == IRQ_TYPE_LEVEL_HIGH)
+ irq_set_handler_locked(d, handle_level_irq);
+ else
+ irq_set_handler_locked(d, handle_simple_irq);
+ return 0;
+ }
+ irq_set_handler_locked(d, handle_bad_irq);
+ return -EINVAL;
+}
+
+static unsigned int altera_gpio_irq_startup(struct irq_data *d)
+{
+ altera_gpio_irq_unmask(d);
+
+ return 0;
+}
+
+static int altera_gpio_get(struct gpio_chip *gc, unsigned offset)
+{
+ struct of_mm_gpio_chip *mm_gc;
+
+ mm_gc = to_of_mm_gpio_chip(gc);
+
+ return !!(readl(mm_gc->regs + ALTERA_GPIO_DATA) & BIT(offset));
+}
+
+static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+ struct of_mm_gpio_chip *mm_gc;
+ struct altera_gpio_chip *chip;
+ unsigned long flags;
+ unsigned int data_reg;
+
+ mm_gc = to_of_mm_gpio_chip(gc);
+ chip = gpiochip_get_data(gc);
+
+ raw_spin_lock_irqsave(&chip->gpio_lock, flags);
+ data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
+ if (value)
+ data_reg |= BIT(offset);
+ else
+ data_reg &= ~BIT(offset);
+ writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
+ raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
+}
+
+static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+ struct of_mm_gpio_chip *mm_gc;
+ struct altera_gpio_chip *chip;
+ unsigned long flags;
+ unsigned int gpio_ddr;
+
+ mm_gc = to_of_mm_gpio_chip(gc);
+ chip = gpiochip_get_data(gc);
+
+ raw_spin_lock_irqsave(&chip->gpio_lock, flags);
+ /* Set pin as input, assumes software controlled IP */
+ gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
+ gpio_ddr &= ~BIT(offset);
+ writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
+ raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
+
+ return 0;
+}
+
+static int altera_gpio_direction_output(struct gpio_chip *gc,
+ unsigned offset, int value)
+{
+ struct of_mm_gpio_chip *mm_gc;
+ struct altera_gpio_chip *chip;
+ unsigned long flags;
+ unsigned int data_reg, gpio_ddr;
+
+ mm_gc = to_of_mm_gpio_chip(gc);
+ chip = gpiochip_get_data(gc);
+
+ raw_spin_lock_irqsave(&chip->gpio_lock, flags);
+ /* Sets the GPIO value */
+ data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
+ if (value)
+ data_reg |= BIT(offset);
+ else
+ data_reg &= ~BIT(offset);
+ writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
+
+ /* Set pin as output, assumes software controlled IP */
+ gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
+ gpio_ddr |= BIT(offset);
+ writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
+ raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
+
+ return 0;
+}
+
+static void altera_gpio_irq_edge_handler(struct irq_desc *desc)
+{
+ struct altera_gpio_chip *altera_gc;
+ struct irq_chip *chip;
+ struct of_mm_gpio_chip *mm_gc;
+ struct irq_domain *irqdomain;
+ unsigned long status;
+ int i;
+
+ altera_gc = gpiochip_get_data(irq_desc_get_handler_data(desc));
+ chip = irq_desc_get_chip(desc);
+ mm_gc = &altera_gc->mmchip;
+ irqdomain = altera_gc->mmchip.gc.irq.domain;
+
+ chained_irq_enter(chip, desc);
+
+ while ((status =
+ (readl(mm_gc->regs + ALTERA_GPIO_EDGE_CAP) &
+ readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK)))) {
+ writel(status, mm_gc->regs + ALTERA_GPIO_EDGE_CAP);
+ for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
+ generic_handle_irq(irq_find_mapping(irqdomain, i));
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void altera_gpio_irq_leveL_high_handler(struct irq_desc *desc)
+{
+ struct altera_gpio_chip *altera_gc;
+ struct irq_chip *chip;
+ struct of_mm_gpio_chip *mm_gc;
+ struct irq_domain *irqdomain;
+ unsigned long status;
+ int i;
+
+ altera_gc = gpiochip_get_data(irq_desc_get_handler_data(desc));
+ chip = irq_desc_get_chip(desc);
+ mm_gc = &altera_gc->mmchip;
+ irqdomain = altera_gc->mmchip.gc.irq.domain;
+
+ chained_irq_enter(chip, desc);
+
+ status = readl(mm_gc->regs + ALTERA_GPIO_DATA);
+ status &= readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
+
+ for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
+ generic_handle_irq(irq_find_mapping(irqdomain, i));
+ }
+ chained_irq_exit(chip, desc);
+}
+
+static int altera_gpio_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ int reg, ret;
+ struct altera_gpio_chip *altera_gc;
+ struct gpio_irq_chip *girq;
+
+ altera_gc = devm_kzalloc(&pdev->dev, sizeof(*altera_gc), GFP_KERNEL);
+ if (!altera_gc)
+ return -ENOMEM;
+
+ raw_spin_lock_init(&altera_gc->gpio_lock);
+
+ if (of_property_read_u32(node, "altr,ngpio", &reg))
+ /* By default assume maximum ngpio */
+ altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
+ else
+ altera_gc->mmchip.gc.ngpio = reg;
+
+ if (altera_gc->mmchip.gc.ngpio > ALTERA_GPIO_MAX_NGPIO) {
+ dev_warn(&pdev->dev,
+ "ngpio is greater than %d, defaulting to %d\n",
+ ALTERA_GPIO_MAX_NGPIO, ALTERA_GPIO_MAX_NGPIO);
+ altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
+ }
+
+ altera_gc->mmchip.gc.direction_input = altera_gpio_direction_input;
+ altera_gc->mmchip.gc.direction_output = altera_gpio_direction_output;
+ altera_gc->mmchip.gc.get = altera_gpio_get;
+ altera_gc->mmchip.gc.set = altera_gpio_set;
+ altera_gc->mmchip.gc.owner = THIS_MODULE;
+ altera_gc->mmchip.gc.parent = &pdev->dev;
+
+ altera_gc->mapped_irq = platform_get_irq_optional(pdev, 0);
+
+ if (altera_gc->mapped_irq < 0)
+ goto skip_irq;
+
+ if (of_property_read_u32(node, "altr,interrupt-type", &reg)) {
+ dev_err(&pdev->dev,
+ "altr,interrupt-type value not set in device tree\n");
+ return -EINVAL;
+ }
+ altera_gc->interrupt_trigger = reg;
+
+ altera_gc->irq_chip.name = "altera-gpio";
+ altera_gc->irq_chip.irq_mask = altera_gpio_irq_mask;
+ altera_gc->irq_chip.irq_unmask = altera_gpio_irq_unmask;
+ altera_gc->irq_chip.irq_set_type = altera_gpio_irq_set_type;
+ altera_gc->irq_chip.irq_startup = altera_gpio_irq_startup;
+ altera_gc->irq_chip.irq_shutdown = altera_gpio_irq_mask;
+
+ girq = &altera_gc->mmchip.gc.irq;
+ girq->chip = &altera_gc->irq_chip;
+ if (altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH)
+ girq->parent_handler = altera_gpio_irq_leveL_high_handler;
+ else
+ girq->parent_handler = altera_gpio_irq_edge_handler;
+ girq->num_parents = 1;
+ girq->parents = devm_kcalloc(&pdev->dev, 1, sizeof(*girq->parents),
+ GFP_KERNEL);
+ if (!girq->parents)
+ return -ENOMEM;
+ girq->default_type = IRQ_TYPE_NONE;
+ girq->handler = handle_bad_irq;
+ girq->parents[0] = altera_gc->mapped_irq;
+
+skip_irq:
+ ret = of_mm_gpiochip_add_data(node, &altera_gc->mmchip, altera_gc);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed adding memory mapped gpiochip\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, altera_gc);
+
+ return 0;
+}
+
+static int altera_gpio_remove(struct platform_device *pdev)
+{
+ struct altera_gpio_chip *altera_gc = platform_get_drvdata(pdev);
+
+ of_mm_gpiochip_remove(&altera_gc->mmchip);
+
+ return 0;
+}
+
+static const struct of_device_id altera_gpio_of_match[] = {
+ { .compatible = "altr,pio-1.0", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, altera_gpio_of_match);
+
+static struct platform_driver altera_gpio_driver = {
+ .driver = {
+ .name = "altera_gpio",
+ .of_match_table = of_match_ptr(altera_gpio_of_match),
+ },
+ .probe = altera_gpio_probe,
+ .remove = altera_gpio_remove,
+};
+
+static int __init altera_gpio_init(void)
+{
+ return platform_driver_register(&altera_gpio_driver);
+}
+subsys_initcall(altera_gpio_init);
+
+static void __exit altera_gpio_exit(void)
+{
+ platform_driver_unregister(&altera_gpio_driver);
+}
+module_exit(altera_gpio_exit);
+
+MODULE_AUTHOR("Tien Hock Loh <thloh@altera.com>");
+MODULE_DESCRIPTION("Altera GPIO driver");
+MODULE_LICENSE("GPL");