diff options
Diffstat (limited to 'drivers/gpio/gpio-dwapb.c')
| -rw-r--r-- | drivers/gpio/gpio-dwapb.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c new file mode 100644 index 0000000..ed5711f --- /dev/null +++ b/drivers/gpio/gpio-dwapb.c @@ -0,0 +1,438 @@ +/* + * Copyright (c) 2011 Jamie Iles + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * All enquiries to support@picochip.com + */ +#include <linux/basic_mmio_gpio.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +#define GPIO_SWPORTA_DR 0x00 +#define GPIO_SWPORTA_DDR 0x04 +#define GPIO_SWPORTB_DR 0x0c +#define GPIO_SWPORTB_DDR 0x10 +#define GPIO_SWPORTC_DR 0x18 +#define GPIO_SWPORTC_DDR 0x1c +#define GPIO_SWPORTD_DR 0x24 +#define GPIO_SWPORTD_DDR 0x28 +#define GPIO_INTEN 0x30 +#define GPIO_INTMASK 0x34 +#define GPIO_INTTYPE_LEVEL 0x38 +#define GPIO_INT_POLARITY 0x3c +#define GPIO_INTSTATUS 0x40 +#define GPIO_PORTA_EOI 0x4c +#define GPIO_EXT_PORTA 0x50 +#define GPIO_EXT_PORTB 0x54 +#define GPIO_EXT_PORTC 0x58 +#define GPIO_EXT_PORTD 0x5c + +#define DWAPB_MAX_PORTS 4 +#define GPIO_EXT_PORT_SIZE (GPIO_EXT_PORTB - GPIO_EXT_PORTA) +#define GPIO_SWPORT_DR_SIZE (GPIO_SWPORTB_DR - GPIO_SWPORTA_DR) +#define GPIO_SWPORT_DDR_SIZE (GPIO_SWPORTB_DDR - GPIO_SWPORTA_DDR) + +struct dwapb_gpio; + +struct dwapb_gpio_port { + struct bgpio_chip bgc; + bool is_registered; + struct dwapb_gpio *gpio; +}; + +struct dwapb_gpio { + struct device *dev; + void __iomem *regs; + struct dwapb_gpio_port *ports; + unsigned int nr_ports; + struct irq_domain *domain; +}; + +static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset) +{ + struct bgpio_chip *bgc = to_bgpio_chip(gc); + struct dwapb_gpio_port *port = container_of(bgc, struct + dwapb_gpio_port, bgc); + struct dwapb_gpio *gpio = port->gpio; + + return irq_find_mapping(gpio->domain, offset); +} + +static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs) +{ + u32 v = readl(gpio->regs + GPIO_INT_POLARITY); + + if (gpio_get_value(gpio->ports[0].bgc.gc.base + offs)) + v &= ~BIT(offs); + else + v |= BIT(offs); + + writel(v, gpio->regs + GPIO_INT_POLARITY); +} + +static void dwapb_irq_handler(u32 irq, struct irq_desc *desc) +{ + struct dwapb_gpio *gpio = irq_get_handler_data(irq); + struct irq_chip *chip = irq_desc_get_chip(desc); + u32 irq_status = readl_relaxed(gpio->regs + GPIO_INTSTATUS); + + while (irq_status) { + int hwirq = fls(irq_status) - 1; + int gpio_irq = irq_find_mapping(gpio->domain, hwirq); + + generic_handle_irq(gpio_irq); + irq_status &= ~BIT(hwirq); + + if ((irq_get_trigger_type(gpio_irq) & IRQ_TYPE_SENSE_MASK) + == IRQ_TYPE_EDGE_BOTH) + dwapb_toggle_trigger(gpio, hwirq); + } + + if (chip->irq_eoi) + chip->irq_eoi(irq_desc_get_irq_data(desc)); +} + +static void dwapb_irq_enable(struct irq_data *d) +{ + struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = igc->private; + struct bgpio_chip *bgc = &gpio->ports[0].bgc; + unsigned long flags; + u32 val; + + spin_lock_irqsave(&bgc->lock, flags); + val = readl(gpio->regs + GPIO_INTEN); + val |= BIT(d->hwirq); + writel(val, gpio->regs + GPIO_INTEN); + spin_unlock_irqrestore(&bgc->lock, flags); +} + +static void dwapb_irq_disable(struct irq_data *d) +{ + struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = igc->private; + struct bgpio_chip *bgc = &gpio->ports[0].bgc; + unsigned long flags; + u32 val; + + spin_lock_irqsave(&bgc->lock, flags); + val = readl(gpio->regs + GPIO_INTEN); + val &= ~BIT(d->hwirq); + writel(val, gpio->regs + GPIO_INTEN); + spin_unlock_irqrestore(&bgc->lock, flags); +} + +static int dwapb_irq_reqres(struct irq_data *d) +{ + struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = igc->private; + struct bgpio_chip *bgc = &gpio->ports[0].bgc; + + if (gpio_lock_as_irq(&bgc->gc, irqd_to_hwirq(d))) { + dev_err(gpio->dev, "unable to lock HW IRQ %lu for IRQ\n", + irqd_to_hwirq(d)); + return -EINVAL; + } + return 0; +} + +static void dwapb_irq_relres(struct irq_data *d) +{ + struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = igc->private; + struct bgpio_chip *bgc = &gpio->ports[0].bgc; + + gpio_unlock_as_irq(&bgc->gc, irqd_to_hwirq(d)); +} + +static int dwapb_irq_set_type(struct irq_data *d, u32 type) +{ + struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d); + struct dwapb_gpio *gpio = igc->private; + struct bgpio_chip *bgc = &gpio->ports[0].bgc; + int bit = d->hwirq; + unsigned long level, polarity, flags; + + if (type & ~(IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING | + IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) + return -EINVAL; + + spin_lock_irqsave(&bgc->lock, flags); + level = readl(gpio->regs + GPIO_INTTYPE_LEVEL); + polarity = readl(gpio->regs + GPIO_INT_POLARITY); + + switch (type) { + case IRQ_TYPE_EDGE_BOTH: + level |= BIT(bit); + dwapb_toggle_trigger(gpio, bit); + break; + case IRQ_TYPE_EDGE_RISING: + level |= BIT(bit); + polarity |= BIT(bit); + break; + case IRQ_TYPE_EDGE_FALLING: + level |= BIT(bit); + polarity &= ~BIT(bit); + break; + case IRQ_TYPE_LEVEL_HIGH: + level &= ~BIT(bit); + polarity |= BIT(bit); + break; + case IRQ_TYPE_LEVEL_LOW: + level &= ~BIT(bit); + polarity &= ~BIT(bit); + break; + } + + writel(level, gpio->regs + GPIO_INTTYPE_LEVEL); + writel(polarity, gpio->regs + GPIO_INT_POLARITY); + spin_unlock_irqrestore(&bgc->lock, flags); + + return 0; +} + +static void dwapb_configure_irqs(struct dwapb_gpio *gpio, + struct dwapb_gpio_port *port) +{ + struct gpio_chip *gc = &port->bgc.gc; + struct device_node *node = gc->of_node; + struct irq_chip_generic *irq_gc; + unsigned int hwirq, ngpio = gc->ngpio; + struct irq_chip_type *ct; + int err, irq; + + irq = irq_of_parse_and_map(node, 0); + if (!irq) { + dev_warn(gpio->dev, "no irq for bank %s\n", + port->bgc.gc.of_node->full_name); + return; + } + + gpio->domain = irq_domain_add_linear(node, ngpio, + &irq_generic_chip_ops, gpio); + if (!gpio->domain) + return; + + err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 1, + "gpio-dwapb", handle_level_irq, + IRQ_NOREQUEST, 0, + IRQ_GC_INIT_NESTED_LOCK); + if (err) { + dev_info(gpio->dev, "irq_alloc_domain_generic_chips failed\n"); + irq_domain_remove(gpio->domain); + gpio->domain = NULL; + return; + } + + irq_gc = irq_get_domain_generic_chip(gpio->domain, 0); + if (!irq_gc) { + irq_domain_remove(gpio->domain); + gpio->domain = NULL; + return; + } + + irq_gc->reg_base = gpio->regs; + irq_gc->private = gpio; + + ct = irq_gc->chip_types; + ct->chip.irq_ack = irq_gc_ack_set_bit; + ct->chip.irq_mask = irq_gc_mask_set_bit; + ct->chip.irq_unmask = irq_gc_mask_clr_bit; + ct->chip.irq_set_type = dwapb_irq_set_type; + ct->chip.irq_enable = dwapb_irq_enable; + ct->chip.irq_disable = dwapb_irq_disable; + ct->chip.irq_request_resources = dwapb_irq_reqres; + ct->chip.irq_release_resources = dwapb_irq_relres; + ct->regs.ack = GPIO_PORTA_EOI; + ct->regs.mask = GPIO_INTMASK; + + irq_setup_generic_chip(irq_gc, IRQ_MSK(port->bgc.gc.ngpio), + IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0); + + irq_set_chained_handler(irq, dwapb_irq_handler); + irq_set_handler_data(irq, gpio); + + for (hwirq = 0 ; hwirq < ngpio ; hwirq++) + irq_create_mapping(gpio->domain, hwirq); + + port->bgc.gc.to_irq = dwapb_gpio_to_irq; +} + +static void dwapb_irq_teardown(struct dwapb_gpio *gpio) +{ + struct dwapb_gpio_port *port = &gpio->ports[0]; + struct gpio_chip *gc = &port->bgc.gc; + unsigned int ngpio = gc->ngpio; + irq_hw_number_t hwirq; + + if (!gpio->domain) + return; + + for (hwirq = 0 ; hwirq < ngpio ; hwirq++) + irq_dispose_mapping(irq_find_mapping(gpio->domain, hwirq)); + + irq_domain_remove(gpio->domain); + gpio->domain = NULL; +} + +static int dwapb_gpio_add_port(struct dwapb_gpio *gpio, + struct device_node *port_np, + unsigned int offs) +{ + struct dwapb_gpio_port *port; + u32 port_idx, ngpio; + void __iomem *dat, *set, *dirout; + int err; + + if (of_property_read_u32(port_np, "reg", &port_idx) || + port_idx >= DWAPB_MAX_PORTS) { + dev_err(gpio->dev, "missing/invalid port index for %s\n", + port_np->full_name); + return -EINVAL; + } + + port = &gpio->ports[offs]; + port->gpio = gpio; + + if (of_property_read_u32(port_np, "snps,nr-gpios", &ngpio)) { + dev_info(gpio->dev, "failed to get number of gpios for %s\n", + port_np->full_name); + ngpio = 32; + } + + dat = gpio->regs + GPIO_EXT_PORTA + (port_idx * GPIO_EXT_PORT_SIZE); + set = gpio->regs + GPIO_SWPORTA_DR + (port_idx * GPIO_SWPORT_DR_SIZE); + dirout = gpio->regs + GPIO_SWPORTA_DDR + + (port_idx * GPIO_SWPORT_DDR_SIZE); + + err = bgpio_init(&port->bgc, gpio->dev, 4, dat, set, NULL, dirout, + NULL, false); + if (err) { + dev_err(gpio->dev, "failed to init gpio chip for %s\n", + port_np->full_name); + return err; + } + + port->bgc.gc.ngpio = ngpio; + port->bgc.gc.of_node = port_np; + + /* + * Only port A can provide interrupts in all configurations of the IP. + */ + if (port_idx == 0 && + of_property_read_bool(port_np, "interrupt-controller")) + dwapb_configure_irqs(gpio, port); + + err = gpiochip_add(&port->bgc.gc); + if (err) + dev_err(gpio->dev, "failed to register gpiochip for %s\n", + port_np->full_name); + else + port->is_registered = true; + + return err; +} + +static void dwapb_gpio_unregister(struct dwapb_gpio *gpio) +{ + unsigned int m; + + for (m = 0; m < gpio->nr_ports; ++m) + if (gpio->ports[m].is_registered) + WARN_ON(gpiochip_remove(&gpio->ports[m].bgc.gc)); +} + +static int dwapb_gpio_probe(struct platform_device *pdev) +{ + struct resource *res; + struct dwapb_gpio *gpio; + struct device_node *np; + int err; + unsigned int offs = 0; + + gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) + return -ENOMEM; + gpio->dev = &pdev->dev; + + gpio->nr_ports = of_get_child_count(pdev->dev.of_node); + if (!gpio->nr_ports) { + err = -EINVAL; + goto out_err; + } + gpio->ports = devm_kzalloc(&pdev->dev, gpio->nr_ports * + sizeof(*gpio->ports), GFP_KERNEL); + if (!gpio->ports) { + err = -ENOMEM; + goto out_err; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + gpio->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(gpio->regs)) { + err = PTR_ERR(gpio->regs); + goto out_err; + } + + for_each_child_of_node(pdev->dev.of_node, np) { + err = dwapb_gpio_add_port(gpio, np, offs++); + if (err) + goto out_unregister; + } + platform_set_drvdata(pdev, gpio); + + return 0; + +out_unregister: + dwapb_gpio_unregister(gpio); + dwapb_irq_teardown(gpio); + +out_err: + return err; +} + +static int dwapb_gpio_remove(struct platform_device *pdev) +{ + struct dwapb_gpio *gpio = platform_get_drvdata(pdev); + + dwapb_gpio_unregister(gpio); + dwapb_irq_teardown(gpio); + + return 0; +} + +static const struct of_device_id dwapb_of_match[] = { + { .compatible = "snps,dw-apb-gpio" }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, dwapb_of_match); + +static struct platform_driver dwapb_gpio_driver = { + .driver = { + .name = "gpio-dwapb", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(dwapb_of_match), + }, + .probe = dwapb_gpio_probe, + .remove = dwapb_gpio_remove, +}; + +module_platform_driver(dwapb_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jamie Iles"); +MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver"); |
