--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2017-2018 Cadence
+ *
+ * Authors:
+ * Jan Kotas <jank@cadence.com>
+ * Boris Brezillon <boris.brezillon@free-electrons.com>
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define CDNS_GPIO_BYPASS_MODE 0x00
+#define CDNS_GPIO_DIRECTION_MODE 0x04
+#define CDNS_GPIO_OUTPUT_EN 0x08
+#define CDNS_GPIO_OUTPUT_VALUE 0x0c
+#define CDNS_GPIO_INPUT_VALUE 0x10
+#define CDNS_GPIO_IRQ_MASK 0x14
+#define CDNS_GPIO_IRQ_EN 0x18
+#define CDNS_GPIO_IRQ_DIS 0x1c
+#define CDNS_GPIO_IRQ_STATUS 0x20
+#define CDNS_GPIO_IRQ_TYPE 0x24
+#define CDNS_GPIO_IRQ_VALUE 0x28
+#define CDNS_GPIO_IRQ_ANY_EDGE 0x2c
+
+struct cdns_gpio_chip {
+ struct gpio_chip gc;
+ struct clk *pclk;
+ void __iomem *regs;
+ u32 bypass_orig;
+};
+
+static int cdns_gpio_request(struct gpio_chip *chip, unsigned int offset)
+{
+ struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->bgpio_lock, flags);
+
+ iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) & ~BIT(offset),
+ cgpio->regs + CDNS_GPIO_BYPASS_MODE);
+
+ spin_unlock_irqrestore(&chip->bgpio_lock, flags);
+ return 0;
+}
+
+static void cdns_gpio_free(struct gpio_chip *chip, unsigned int offset)
+{
+ struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->bgpio_lock, flags);
+
+ iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) |
+ (BIT(offset) & cgpio->bypass_orig),
+ cgpio->regs + CDNS_GPIO_BYPASS_MODE);
+
+ spin_unlock_irqrestore(&chip->bgpio_lock, flags);
+}
+
+static void cdns_gpio_irq_mask(struct irq_data *d)
+{
+ struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+ struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
+
+ iowrite32(BIT(d->hwirq), cgpio->regs + CDNS_GPIO_IRQ_DIS);
+}
+
+static void cdns_gpio_irq_unmask(struct irq_data *d)
+{
+ struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+ struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
+
+ iowrite32(BIT(d->hwirq), cgpio->regs + CDNS_GPIO_IRQ_EN);
+}
+
+static int cdns_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+ struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
+ unsigned long flags;
+ u32 int_value;
+ u32 int_type;
+ u32 mask = BIT(d->hwirq);
+ int ret = 0;
+
+ spin_lock_irqsave(&chip->bgpio_lock, flags);
+
+ int_value = ioread32(cgpio->regs + CDNS_GPIO_IRQ_VALUE) & ~mask;
+ int_type = ioread32(cgpio->regs + CDNS_GPIO_IRQ_TYPE) & ~mask;
+
+ /*
+ * The GPIO controller doesn't have an ACK register.
+ * All interrupt statuses are cleared on a status register read.
+ * Don't support edge interrupts for now.
+ */
+
+ if (type == IRQ_TYPE_LEVEL_HIGH) {
+ int_type |= mask;
+ int_value |= mask;
+ } else if (type == IRQ_TYPE_LEVEL_LOW) {
+ int_type |= mask;
+ } else {
+ ret = -EINVAL;
+ goto err_irq_type;
+ }
+
+ iowrite32(int_value, cgpio->regs + CDNS_GPIO_IRQ_VALUE);
+ iowrite32(int_type, cgpio->regs + CDNS_GPIO_IRQ_TYPE);
+
+err_irq_type:
+ spin_unlock_irqrestore(&chip->bgpio_lock, flags);
+ return ret;
+}
+
+static void cdns_gpio_irq_handler(struct irq_desc *desc)
+{
+ struct gpio_chip *chip = irq_desc_get_handler_data(desc);
+ struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
+ struct irq_chip *irqchip = irq_desc_get_chip(desc);
+ unsigned long status;
+ int hwirq;
+
+ chained_irq_enter(irqchip, desc);
+
+ status = ioread32(cgpio->regs + CDNS_GPIO_IRQ_STATUS) &
+ ~ioread32(cgpio->regs + CDNS_GPIO_IRQ_MASK);
+
+ for_each_set_bit(hwirq, &status, chip->ngpio)
+ generic_handle_irq(irq_find_mapping(chip->irq.domain, hwirq));
+
+ chained_irq_exit(irqchip, desc);
+}
+
+static struct irq_chip cdns_gpio_irqchip = {
+ .name = "cdns-gpio",
+ .irq_mask = cdns_gpio_irq_mask,
+ .irq_unmask = cdns_gpio_irq_unmask,
+ .irq_set_type = cdns_gpio_irq_set_type
+};
+
+static int cdns_gpio_probe(struct platform_device *pdev)
+{
+ struct cdns_gpio_chip *cgpio;
+ struct resource *res;
+ int ret, irq;
+ u32 dir_prev;
+ u32 num_gpios = 32;
+
+ cgpio = devm_kzalloc(&pdev->dev, sizeof(*cgpio), GFP_KERNEL);
+ if (!cgpio)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ cgpio->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(cgpio->regs))
+ return PTR_ERR(cgpio->regs);
+
+ of_property_read_u32(pdev->dev.of_node, "ngpios", &num_gpios);
+
+ if (num_gpios > 32) {
+ dev_err(&pdev->dev, "ngpios must be less or equal 32\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Set all pins as inputs by default, otherwise:
+ * gpiochip_lock_as_irq:
+ * tried to flag a GPIO set as output for IRQ
+ * Generic GPIO driver stores the direction value internally,
+ * so it needs to be changed before bgpio_init() is called.
+ */
+ dir_prev = ioread32(cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
+ iowrite32(GENMASK(num_gpios - 1, 0),
+ cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
+
+ ret = bgpio_init(&cgpio->gc, &pdev->dev, 4,
+ cgpio->regs + CDNS_GPIO_INPUT_VALUE,
+ cgpio->regs + CDNS_GPIO_OUTPUT_VALUE,
+ NULL,
+ NULL,
+ cgpio->regs + CDNS_GPIO_DIRECTION_MODE,
+ BGPIOF_READ_OUTPUT_REG_SET);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to register generic gpio, %d\n",
+ ret);
+ goto err_revert_dir;
+ }
+
+ cgpio->gc.label = dev_name(&pdev->dev);
+ cgpio->gc.ngpio = num_gpios;
+ cgpio->gc.parent = &pdev->dev;
+ cgpio->gc.base = -1;
+ cgpio->gc.owner = THIS_MODULE;
+ cgpio->gc.request = cdns_gpio_request;
+ cgpio->gc.free = cdns_gpio_free;
+
+ cgpio->pclk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(cgpio->pclk)) {
+ ret = PTR_ERR(cgpio->pclk);
+ dev_err(&pdev->dev,
+ "Failed to retrieve peripheral clock, %d\n", ret);
+ goto err_revert_dir;
+ }
+
+ ret = clk_prepare_enable(cgpio->pclk);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to enable the peripheral clock, %d\n", ret);
+ goto err_revert_dir;
+ }
+
+ ret = devm_gpiochip_add_data(&pdev->dev, &cgpio->gc, cgpio);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
+ goto err_disable_clk;
+ }
+
+ /*
+ * irq_chip support
+ */
+ irq = platform_get_irq(pdev, 0);
+ if (irq >= 0) {
+ ret = gpiochip_irqchip_add(&cgpio->gc, &cdns_gpio_irqchip,
+ 0, handle_level_irq,
+ IRQ_TYPE_NONE);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not add irqchip, %d\n",
+ ret);
+ goto err_disable_clk;
+ }
+ gpiochip_set_chained_irqchip(&cgpio->gc, &cdns_gpio_irqchip,
+ irq, cdns_gpio_irq_handler);
+ }
+
+ cgpio->bypass_orig = ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE);
+
+ /*
+ * Enable gpio outputs, ignored for input direction
+ */
+ iowrite32(GENMASK(num_gpios - 1, 0),
+ cgpio->regs + CDNS_GPIO_OUTPUT_EN);
+ iowrite32(0, cgpio->regs + CDNS_GPIO_BYPASS_MODE);
+
+ platform_set_drvdata(pdev, cgpio);
+ return 0;
+
+err_disable_clk:
+ clk_disable_unprepare(cgpio->pclk);
+
+err_revert_dir:
+ iowrite32(dir_prev, cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
+
+ return ret;
+}
+
+static int cdns_gpio_remove(struct platform_device *pdev)
+{
+ struct cdns_gpio_chip *cgpio = platform_get_drvdata(pdev);
+
+ iowrite32(cgpio->bypass_orig, cgpio->regs + CDNS_GPIO_BYPASS_MODE);
+ clk_disable_unprepare(cgpio->pclk);
+
+ return 0;
+}
+
+static const struct of_device_id cdns_of_ids[] = {
+ { .compatible = "cdns,gpio-r1p02" },
+ { /* sentinel */ },
+};
+
+static struct platform_driver cdns_gpio_driver = {
+ .driver = {
+ .name = "cdns-gpio",
+ .of_match_table = cdns_of_ids,
+ },
+ .probe = cdns_gpio_probe,
+ .remove = cdns_gpio_remove,
+};
+module_platform_driver(cdns_gpio_driver);
+
+MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
+MODULE_DESCRIPTION("Cadence GPIO driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:cdns-gpio");
projects / linux.git / commitdiff