|  | // 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 | 
|  | * @base: remapped I/O-memory base | 
|  | * @clk: silicon clock | 
|  | */ | 
|  | struct ftgpio_gpio { | 
|  | struct device *dev; | 
|  | struct gpio_chip gc; | 
|  | 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); | 
|  | gpiochip_disable_irq(gc, irqd_to_hwirq(d)); | 
|  | } | 
|  |  | 
|  | 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; | 
|  |  | 
|  | gpiochip_enable_irq(gc, irqd_to_hwirq(d)); | 
|  | 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_domain_irq(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 | 
|  | * desirable 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 const struct irq_chip ftgpio_irq_chip = { | 
|  | .name = "FTGPIO010", | 
|  | .irq_ack = ftgpio_gpio_ack_irq, | 
|  | .irq_mask = ftgpio_gpio_mask_irq, | 
|  | .irq_unmask = ftgpio_gpio_unmask_irq, | 
|  | .irq_set_type = ftgpio_gpio_set_irq_type, | 
|  | .flags = IRQCHIP_IMMUTABLE, | 
|  | GPIOCHIP_IRQ_RESOURCE_HELPERS, | 
|  | }; | 
|  |  | 
|  | static int ftgpio_gpio_probe(struct platform_device *pdev) | 
|  | { | 
|  | struct device *dev = &pdev->dev; | 
|  | struct ftgpio_gpio *g; | 
|  | struct gpio_irq_chip *girq; | 
|  | int irq; | 
|  | int ret; | 
|  |  | 
|  | g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL); | 
|  | if (!g) | 
|  | return -ENOMEM; | 
|  |  | 
|  | g->dev = dev; | 
|  |  | 
|  | g->base = devm_platform_ioremap_resource(pdev, 0); | 
|  | if (IS_ERR(g->base)) | 
|  | return PTR_ERR(g->base); | 
|  |  | 
|  | irq = platform_get_irq(pdev, 0); | 
|  | if (irq < 0) | 
|  | return irq; | 
|  |  | 
|  | 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 = dev_name(dev); | 
|  | 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; | 
|  |  | 
|  | girq = &g->gc.irq; | 
|  | gpio_irq_chip_set_chip(girq, &ftgpio_irq_chip); | 
|  | girq->parent_handler = ftgpio_gpio_irq_handler; | 
|  | girq->num_parents = 1; | 
|  | girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents), | 
|  | GFP_KERNEL); | 
|  | if (!girq->parents) { | 
|  | ret = -ENOMEM; | 
|  | goto dis_clk; | 
|  | } | 
|  | girq->default_type = IRQ_TYPE_NONE; | 
|  | girq->handler = handle_bad_irq; | 
|  | girq->parents[0] = irq; | 
|  |  | 
|  | /* 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); | 
|  |  | 
|  | ret = devm_gpiochip_add_data(dev, &g->gc, g); | 
|  | if (ret) | 
|  | goto dis_clk; | 
|  |  | 
|  | platform_set_drvdata(pdev, g); | 
|  | dev_info(dev, "FTGPIO010 @%p registered\n", g->base); | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | dis_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); | 
|  |  | 
|  | 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 = ftgpio_gpio_of_match, | 
|  | }, | 
|  | .probe = ftgpio_gpio_probe, | 
|  | .remove = ftgpio_gpio_remove, | 
|  | }; | 
|  | builtin_platform_driver(ftgpio_gpio_driver); |