| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Faraday Technolog FTGPIO010 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/bitops.h> |
| #include <linux/clk.h> |
| |
| /* GPIO registers definition */ |
| #define GPIO_DATA_OUT 0x00 |
| #define GPIO_DATA_IN 0x04 |
| #define GPIO_DIR 0x08 |
| #define GPIO_BYPASS_IN 0x0C |
| #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_RAW 0x24 |
| #define GPIO_INT_STAT_MASKED 0x28 |
| #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 ftgpio_gpio - Gemini GPIO state container |
| * @dev: containing device for this instance |
| * @gc: gpiochip for this instance |
| * @irq: irqchip for this instance |
| * @base: remapped I/O-memory base |
| * @clk: silicon clock |
| */ |
| struct ftgpio_gpio { |
| struct device *dev; |
| struct gpio_chip gc; |
| struct irq_chip irq; |
| void __iomem *base; |
| struct clk *clk; |
| }; |
| |
| static void ftgpio_gpio_ack_irq(struct irq_data *d) |
| { |
| struct gpio_chip *gc = irq_data_get_irq_chip_data(d); |
| struct ftgpio_gpio *g = gpiochip_get_data(gc); |
| |
| writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR); |
| } |
| |
| static void ftgpio_gpio_mask_irq(struct irq_data *d) |
| { |
| struct gpio_chip *gc = irq_data_get_irq_chip_data(d); |
| struct ftgpio_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 ftgpio_gpio_unmask_irq(struct irq_data *d) |
| { |
| struct gpio_chip *gc = irq_data_get_irq_chip_data(d); |
| struct ftgpio_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 ftgpio_gpio_set_irq_type(struct irq_data *d, unsigned int type) |
| { |
| struct gpio_chip *gc = irq_data_get_irq_chip_data(d); |
| struct ftgpio_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); |
| |
| ftgpio_gpio_ack_irq(d); |
| |
| return 0; |
| } |
| |
| static void ftgpio_gpio_irq_handler(struct irq_desc *desc) |
| { |
| struct gpio_chip *gc = irq_desc_get_handler_data(desc); |
| struct ftgpio_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_RAW); |
| if (stat) |
| for_each_set_bit(offset, &stat, gc->ngpio) |
| generic_handle_irq(irq_find_mapping(gc->irq.domain, |
| offset)); |
| |
| chained_irq_exit(irqchip, desc); |
| } |
| |
| static int ftgpio_gpio_set_config(struct gpio_chip *gc, unsigned int offset, |
| unsigned long config) |
| { |
| enum pin_config_param param = pinconf_to_config_param(config); |
| u32 arg = pinconf_to_config_argument(config); |
| struct ftgpio_gpio *g = gpiochip_get_data(gc); |
| unsigned long pclk_freq; |
| u32 deb_div; |
| u32 val; |
| |
| if (param != PIN_CONFIG_INPUT_DEBOUNCE) |
| return -ENOTSUPP; |
| |
| /* |
| * Debounce only works if interrupts are enabled. The manual |
| * states that if PCLK is 66 MHz, and this is set to 0x7D0, then |
| * PCLK is divided down to 33 kHz for the debounce timer. 0x7D0 is |
| * 2000 decimal, so what they mean is simply that the PCLK is |
| * divided by this value. |
| * |
| * As we get a debounce setting in microseconds, we calculate the |
| * desired period time and see if we can get a suitable debounce |
| * time. |
| */ |
| pclk_freq = clk_get_rate(g->clk); |
| deb_div = DIV_ROUND_CLOSEST(pclk_freq, arg); |
| |
| /* This register is only 24 bits wide */ |
| if (deb_div > (1 << 24)) |
| return -ENOTSUPP; |
| |
| dev_dbg(g->dev, "prescale divisor: %08x, resulting frequency %lu Hz\n", |
| deb_div, (pclk_freq/deb_div)); |
| |
| val = readl(g->base + GPIO_DEBOUNCE_PRESCALE); |
| if (val == deb_div) { |
| /* |
| * The debounce timer happens to already be set to the |
| * desireable value, what a coincidence! We can just enable |
| * debounce on this GPIO line and return. This happens more |
| * often than you think, for example when all GPIO keys |
| * on a system are requesting the same debounce interval. |
| */ |
| val = readl(g->base + GPIO_DEBOUNCE_EN); |
| val |= BIT(offset); |
| writel(val, g->base + GPIO_DEBOUNCE_EN); |
| return 0; |
| } |
| |
| val = readl(g->base + GPIO_DEBOUNCE_EN); |
| if (val) { |
| /* |
| * Oh no! Someone is already using the debounce with |
| * another setting than what we need. Bummer. |
| */ |
| return -ENOTSUPP; |
| } |
| |
| /* First come, first serve */ |
| writel(deb_div, g->base + GPIO_DEBOUNCE_PRESCALE); |
| /* Enable debounce */ |
| val |= BIT(offset); |
| writel(val, g->base + GPIO_DEBOUNCE_EN); |
| |
| return 0; |
| } |
| |
| static int ftgpio_gpio_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct resource *res; |
| struct ftgpio_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 <= 0) |
| return irq ? irq : -EINVAL; |
| |
| g->clk = devm_clk_get(dev, NULL); |
| if (!IS_ERR(g->clk)) { |
| ret = clk_prepare_enable(g->clk); |
| if (ret) |
| return ret; |
| } else if (PTR_ERR(g->clk) == -EPROBE_DEFER) { |
| /* |
| * Percolate deferrals, for anything else, |
| * just live without the clocking. |
| */ |
| return PTR_ERR(g->clk); |
| } |
| |
| 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"); |
| goto dis_clk; |
| } |
| g->gc.label = "FTGPIO010"; |
| g->gc.base = -1; |
| g->gc.parent = dev; |
| g->gc.owner = THIS_MODULE; |
| /* ngpio is set by bgpio_init() */ |
| |
| /* We need a silicon clock to do debounce */ |
| if (!IS_ERR(g->clk)) |
| g->gc.set_config = ftgpio_gpio_set_config; |
| |
| ret = devm_gpiochip_add_data(dev, &g->gc, g); |
| if (ret) |
| goto dis_clk; |
| |
| /* 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); |
| |
| /* Clear any use of debounce */ |
| writel(0x0, g->base + GPIO_DEBOUNCE_EN); |
| |
| g->irq.name = "FTGPIO010"; |
| g->irq.irq_ack = ftgpio_gpio_ack_irq; |
| g->irq.irq_mask = ftgpio_gpio_mask_irq; |
| g->irq.irq_unmask = ftgpio_gpio_unmask_irq; |
| g->irq.irq_set_type = ftgpio_gpio_set_irq_type; |
| |
| ret = gpiochip_irqchip_add(&g->gc, &g->irq, |
| 0, handle_bad_irq, |
| IRQ_TYPE_NONE); |
| if (ret) { |
| dev_info(dev, "could not add irqchip\n"); |
| goto dis_clk; |
| } |
| gpiochip_set_chained_irqchip(&g->gc, &g->irq, |
| irq, ftgpio_gpio_irq_handler); |
| |
| platform_set_drvdata(pdev, g); |
| dev_info(dev, "FTGPIO010 @%p registered\n", g->base); |
| |
| return 0; |
| |
| dis_clk: |
| if (!IS_ERR(g->clk)) |
| clk_disable_unprepare(g->clk); |
| return ret; |
| } |
| |
| static int ftgpio_gpio_remove(struct platform_device *pdev) |
| { |
| struct ftgpio_gpio *g = platform_get_drvdata(pdev); |
| |
| if (!IS_ERR(g->clk)) |
| clk_disable_unprepare(g->clk); |
| return 0; |
| } |
| |
| static const struct of_device_id ftgpio_gpio_of_match[] = { |
| { |
| .compatible = "cortina,gemini-gpio", |
| }, |
| { |
| .compatible = "moxa,moxart-gpio", |
| }, |
| { |
| .compatible = "faraday,ftgpio010", |
| }, |
| {}, |
| }; |
| |
| static struct platform_driver ftgpio_gpio_driver = { |
| .driver = { |
| .name = "ftgpio010-gpio", |
| .of_match_table = of_match_ptr(ftgpio_gpio_of_match), |
| }, |
| .probe = ftgpio_gpio_probe, |
| .remove = ftgpio_gpio_remove, |
| }; |
| builtin_platform_driver(ftgpio_gpio_driver); |