// SPDX-License-Identifier: GPL-2.0 // // IXP4 GPIO driver // Copyright (C) 2019 Linus Walleij // // based on previous work and know-how from: // Deepak Saxena #include #include #include #include #include #include #include #include /* Include that go away with DT transition */ #include #include #define IXP4XX_REG_GPOUT 0x00 #define IXP4XX_REG_GPOE 0x04 #define IXP4XX_REG_GPIN 0x08 #define IXP4XX_REG_GPIS 0x0C #define IXP4XX_REG_GPIT1 0x10 #define IXP4XX_REG_GPIT2 0x14 #define IXP4XX_REG_GPCLK 0x18 #define IXP4XX_REG_GPDBSEL 0x1C /* * The hardware uses 3 bits to indicate interrupt "style". * we clear and set these three bits accordingly. The lower 24 * bits in two registers (GPIT1 and GPIT2) are used to set up * the style for 8 lines each for a total of 16 GPIO lines. */ #define IXP4XX_GPIO_STYLE_ACTIVE_HIGH 0x0 #define IXP4XX_GPIO_STYLE_ACTIVE_LOW 0x1 #define IXP4XX_GPIO_STYLE_RISING_EDGE 0x2 #define IXP4XX_GPIO_STYLE_FALLING_EDGE 0x3 #define IXP4XX_GPIO_STYLE_TRANSITIONAL 0x4 #define IXP4XX_GPIO_STYLE_MASK GENMASK(2, 0) #define IXP4XX_GPIO_STYLE_SIZE 3 /** * struct ixp4xx_gpio - IXP4 GPIO state container * @dev: containing device for this instance * @fwnode: the fwnode for this GPIO chip * @gc: gpiochip for this instance * @base: remapped I/O-memory base * @irq_edge: Each bit represents an IRQ: 1: edge-triggered, * 0: level triggered */ struct ixp4xx_gpio { struct device *dev; struct fwnode_handle *fwnode; struct gpio_chip gc; void __iomem *base; unsigned long long irq_edge; }; static void ixp4xx_gpio_irq_ack(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct ixp4xx_gpio *g = gpiochip_get_data(gc); __raw_writel(BIT(d->hwirq), g->base + IXP4XX_REG_GPIS); } static void ixp4xx_gpio_irq_unmask(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct ixp4xx_gpio *g = gpiochip_get_data(gc); /* ACK when unmasking if not edge-triggered */ if (!(g->irq_edge & BIT(d->hwirq))) ixp4xx_gpio_irq_ack(d); irq_chip_unmask_parent(d); } static int ixp4xx_gpio_irq_set_type(struct irq_data *d, unsigned int type) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct ixp4xx_gpio *g = gpiochip_get_data(gc); int line = d->hwirq; unsigned long flags; u32 int_style; u32 int_reg; u32 val; switch (type) { case IRQ_TYPE_EDGE_BOTH: irq_set_handler_locked(d, handle_edge_irq); int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL; g->irq_edge |= BIT(d->hwirq); break; case IRQ_TYPE_EDGE_RISING: irq_set_handler_locked(d, handle_edge_irq); int_style = IXP4XX_GPIO_STYLE_RISING_EDGE; g->irq_edge |= BIT(d->hwirq); break; case IRQ_TYPE_EDGE_FALLING: irq_set_handler_locked(d, handle_edge_irq); int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE; g->irq_edge |= BIT(d->hwirq); break; case IRQ_TYPE_LEVEL_HIGH: irq_set_handler_locked(d, handle_level_irq); int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH; g->irq_edge &= ~BIT(d->hwirq); break; case IRQ_TYPE_LEVEL_LOW: irq_set_handler_locked(d, handle_level_irq); int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW; g->irq_edge &= ~BIT(d->hwirq); break; default: return -EINVAL; } if (line >= 8) { /* pins 8-15 */ line -= 8; int_reg = IXP4XX_REG_GPIT2; } else { /* pins 0-7 */ int_reg = IXP4XX_REG_GPIT1; } spin_lock_irqsave(&g->gc.bgpio_lock, flags); /* Clear the style for the appropriate pin */ val = __raw_readl(g->base + int_reg); val &= ~(IXP4XX_GPIO_STYLE_MASK << (line * IXP4XX_GPIO_STYLE_SIZE)); __raw_writel(val, g->base + int_reg); __raw_writel(BIT(line), g->base + IXP4XX_REG_GPIS); /* Set the new style */ val = __raw_readl(g->base + int_reg); val |= (int_style << (line * IXP4XX_GPIO_STYLE_SIZE)); __raw_writel(val, g->base + int_reg); /* Force-configure this line as an input */ val = __raw_readl(g->base + IXP4XX_REG_GPOE); val |= BIT(d->hwirq); __raw_writel(val, g->base + IXP4XX_REG_GPOE); spin_unlock_irqrestore(&g->gc.bgpio_lock, flags); /* This parent only accept level high (asserted) */ return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH); } static struct irq_chip ixp4xx_gpio_irqchip = { .name = "IXP4GPIO", .irq_ack = ixp4xx_gpio_irq_ack, .irq_mask = irq_chip_mask_parent, .irq_unmask = ixp4xx_gpio_irq_unmask, .irq_set_type = ixp4xx_gpio_irq_set_type, }; static int ixp4xx_gpio_child_to_parent_hwirq(struct gpio_chip *gc, unsigned int child, unsigned int child_type, unsigned int *parent, unsigned int *parent_type) { /* All these interrupts are level high in the CPU */ *parent_type = IRQ_TYPE_LEVEL_HIGH; /* GPIO lines 0..12 have dedicated IRQs */ if (child == 0) { *parent = 6; return 0; } if (child == 1) { *parent = 7; return 0; } if (child >= 2 && child <= 12) { *parent = child + 17; return 0; } return -EINVAL; } static int ixp4xx_gpio_probe(struct platform_device *pdev) { unsigned long flags; struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct irq_domain *parent; struct resource *res; struct ixp4xx_gpio *g; struct gpio_irq_chip *girq; 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); /* * When we convert to device tree we will simply look up the * parent irqdomain using irq_find_host(parent) as parent comes * from IRQCHIP_DECLARE(), then use of_node_to_fwnode() to get * the fwnode. For now we need this boardfile style code. */ if (np) { struct device_node *irq_parent; irq_parent = of_irq_find_parent(np); if (!irq_parent) { dev_err(dev, "no IRQ parent node\n"); return -ENODEV; } parent = irq_find_host(irq_parent); if (!parent) { dev_err(dev, "no IRQ parent domain\n"); return -ENODEV; } g->fwnode = of_node_to_fwnode(np); } else { parent = ixp4xx_get_irq_domain(); g->fwnode = irq_domain_alloc_fwnode(&res->start); if (!g->fwnode) { dev_err(dev, "no domain base\n"); return -ENODEV; } } /* * Make sure GPIO 14 and 15 are NOT used as clocks but GPIO on * specific machines. */ if (machine_is_dsmg600() || machine_is_nas100d()) __raw_writel(0x0, g->base + IXP4XX_REG_GPCLK); /* * This is a very special big-endian ARM issue: when the IXP4xx is * run in big endian mode, all registers in the machine are switched * around to the CPU-native endianness. As you see mostly in the * driver we use __raw_readl()/__raw_writel() to access the registers * in the appropriate order. With the GPIO library we need to specify * byte order explicitly, so this flag needs to be set when compiling * for big endian. */ #if defined(CONFIG_CPU_BIG_ENDIAN) flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER; #else flags = 0; #endif /* Populate and register gpio chip */ ret = bgpio_init(&g->gc, dev, 4, g->base + IXP4XX_REG_GPIN, g->base + IXP4XX_REG_GPOUT, NULL, NULL, g->base + IXP4XX_REG_GPOE, flags); if (ret) { dev_err(dev, "unable to init generic GPIO\n"); return ret; } g->gc.ngpio = 16; g->gc.label = "IXP4XX_GPIO_CHIP"; /* * TODO: when we have migrated to device tree and all GPIOs * are fetched using phandles, set this to -1 to get rid of * the fixed gpiochip base. */ g->gc.base = 0; g->gc.parent = &pdev->dev; g->gc.owner = THIS_MODULE; girq = &g->gc.irq; girq->chip = &ixp4xx_gpio_irqchip; girq->fwnode = g->fwnode; girq->parent_domain = parent; girq->child_to_parent_hwirq = ixp4xx_gpio_child_to_parent_hwirq; girq->handler = handle_bad_irq; girq->default_type = IRQ_TYPE_NONE; ret = devm_gpiochip_add_data(dev, &g->gc, g); if (ret) { dev_err(dev, "failed to add SoC gpiochip\n"); return ret; } platform_set_drvdata(pdev, g); dev_info(dev, "IXP4 GPIO registered\n"); return 0; } static const struct of_device_id ixp4xx_gpio_of_match[] = { { .compatible = "intel,ixp4xx-gpio", }, {}, }; static struct platform_driver ixp4xx_gpio_driver = { .driver = { .name = "ixp4xx-gpio", .of_match_table = of_match_ptr(ixp4xx_gpio_of_match), }, .probe = ixp4xx_gpio_probe, }; builtin_platform_driver(ixp4xx_gpio_driver);