diff options
Diffstat (limited to 'drivers/gpio/gpio-gemini.c')
| -rw-r--r-- | drivers/gpio/gpio-gemini.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-gemini.c b/drivers/gpio/gpio-gemini.c new file mode 100644 index 000000000000..962485163b7f --- /dev/null +++ b/drivers/gpio/gpio-gemini.c @@ -0,0 +1,236 @@ +/* + * Gemini gpiochip and interrupt routines + * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> + * + * Based on arch/arm/mach-gemini/gpio.c: + * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt> + * + * Based on plat-mxc/gpio.c: + * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de> + * Copyright 2008 Juergen Beisert, kernel@pengutronix.de + */ +#include <linux/gpio/driver.h> +#include <linux/io.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/of_gpio.h> +#include <linux/bitops.h> + +/* GPIO registers definition */ +#define GPIO_DATA_OUT 0x00 +#define GPIO_DATA_IN 0x04 +#define GPIO_DIR 0x08 +#define GPIO_DATA_SET 0x10 +#define GPIO_DATA_CLR 0x14 +#define GPIO_PULL_EN 0x18 +#define GPIO_PULL_TYPE 0x1C +#define GPIO_INT_EN 0x20 +#define GPIO_INT_STAT 0x24 +#define GPIO_INT_MASK 0x2C +#define GPIO_INT_CLR 0x30 +#define GPIO_INT_TYPE 0x34 +#define GPIO_INT_BOTH_EDGE 0x38 +#define GPIO_INT_LEVEL 0x3C +#define GPIO_DEBOUNCE_EN 0x40 +#define GPIO_DEBOUNCE_PRESCALE 0x44 + +/** + * struct gemini_gpio - Gemini GPIO state container + * @dev: containing device for this instance + * @gc: gpiochip for this instance + */ +struct gemini_gpio { + struct device *dev; + struct gpio_chip gc; + void __iomem *base; +}; + +static void gemini_gpio_ack_irq(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gemini_gpio *g = gpiochip_get_data(gc); + + writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR); +} + +static void gemini_gpio_mask_irq(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gemini_gpio *g = gpiochip_get_data(gc); + u32 val; + + val = readl(g->base + GPIO_INT_EN); + val &= ~BIT(irqd_to_hwirq(d)); + writel(val, g->base + GPIO_INT_EN); +} + +static void gemini_gpio_unmask_irq(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gemini_gpio *g = gpiochip_get_data(gc); + u32 val; + + val = readl(g->base + GPIO_INT_EN); + val |= BIT(irqd_to_hwirq(d)); + writel(val, g->base + GPIO_INT_EN); +} + +static int gemini_gpio_set_irq_type(struct irq_data *d, unsigned int type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gemini_gpio *g = gpiochip_get_data(gc); + u32 mask = BIT(irqd_to_hwirq(d)); + u32 reg_both, reg_level, reg_type; + + reg_type = readl(g->base + GPIO_INT_TYPE); + reg_level = readl(g->base + GPIO_INT_LEVEL); + reg_both = readl(g->base + GPIO_INT_BOTH_EDGE); + + switch (type) { + case IRQ_TYPE_EDGE_BOTH: + irq_set_handler_locked(d, handle_edge_irq); + reg_type &= ~mask; + reg_both |= mask; + break; + case IRQ_TYPE_EDGE_RISING: + irq_set_handler_locked(d, handle_edge_irq); + reg_type &= ~mask; + reg_both &= ~mask; + reg_level &= ~mask; + break; + case IRQ_TYPE_EDGE_FALLING: + irq_set_handler_locked(d, handle_edge_irq); + reg_type &= ~mask; + reg_both &= ~mask; + reg_level |= mask; + break; + case IRQ_TYPE_LEVEL_HIGH: + irq_set_handler_locked(d, handle_level_irq); + reg_type |= mask; + reg_level &= ~mask; + break; + case IRQ_TYPE_LEVEL_LOW: + irq_set_handler_locked(d, handle_level_irq); + reg_type |= mask; + reg_level |= mask; + break; + default: + irq_set_handler_locked(d, handle_bad_irq); + return -EINVAL; + } + + writel(reg_type, g->base + GPIO_INT_TYPE); + writel(reg_level, g->base + GPIO_INT_LEVEL); + writel(reg_both, g->base + GPIO_INT_BOTH_EDGE); + + gemini_gpio_ack_irq(d); + + return 0; +} + +static struct irq_chip gemini_gpio_irqchip = { + .name = "GPIO", + .irq_ack = gemini_gpio_ack_irq, + .irq_mask = gemini_gpio_mask_irq, + .irq_unmask = gemini_gpio_unmask_irq, + .irq_set_type = gemini_gpio_set_irq_type, +}; + +static void gemini_gpio_irq_handler(struct irq_desc *desc) +{ + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct gemini_gpio *g = gpiochip_get_data(gc); + struct irq_chip *irqchip = irq_desc_get_chip(desc); + int offset; + unsigned long stat; + + chained_irq_enter(irqchip, desc); + + stat = readl(g->base + GPIO_INT_STAT); + if (stat) + for_each_set_bit(offset, &stat, gc->ngpio) + generic_handle_irq(irq_find_mapping(gc->irqdomain, + offset)); + + chained_irq_exit(irqchip, desc); +} + +static int gemini_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct resource *res; + struct gemini_gpio *g; + int irq; + int ret; + + g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL); + if (!g) + return -ENOMEM; + + g->dev = dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + g->base = devm_ioremap_resource(dev, res); + if (IS_ERR(g->base)) + return PTR_ERR(g->base); + + irq = platform_get_irq(pdev, 0); + if (!irq) + return -EINVAL; + + ret = bgpio_init(&g->gc, dev, 4, + g->base + GPIO_DATA_IN, + g->base + GPIO_DATA_SET, + g->base + GPIO_DATA_CLR, + g->base + GPIO_DIR, + NULL, + 0); + if (ret) { + dev_err(dev, "unable to init generic GPIO\n"); + return ret; + } + g->gc.label = "Gemini"; + g->gc.base = -1; + g->gc.parent = dev; + g->gc.owner = THIS_MODULE; + /* ngpio is set by bgpio_init() */ + + ret = devm_gpiochip_add_data(dev, &g->gc, g); + if (ret) + return ret; + + /* Disable, unmask and clear all interrupts */ + writel(0x0, g->base + GPIO_INT_EN); + writel(0x0, g->base + GPIO_INT_MASK); + writel(~0x0, g->base + GPIO_INT_CLR); + + ret = gpiochip_irqchip_add(&g->gc, &gemini_gpio_irqchip, + 0, handle_bad_irq, + IRQ_TYPE_NONE); + if (ret) { + dev_info(dev, "could not add irqchip\n"); + return ret; + } + gpiochip_set_chained_irqchip(&g->gc, &gemini_gpio_irqchip, + irq, gemini_gpio_irq_handler); + + dev_info(dev, "Gemini GPIO @%p registered\n", g->base); + + return 0; +} + +static const struct of_device_id gemini_gpio_of_match[] = { + { + .compatible = "cortina,gemini-gpio", + }, + {}, +}; + +static struct platform_driver gemini_gpio_driver = { + .driver = { + .name = "gemini-gpio", + .of_match_table = of_match_ptr(gemini_gpio_of_match), + }, + .probe = gemini_gpio_probe, +}; +builtin_platform_driver(gemini_gpio_driver); |