diff options
Diffstat (limited to 'drivers/gpio/gpio-hlwd.c')
| -rw-r--r-- | drivers/gpio/gpio-hlwd.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-hlwd.c b/drivers/gpio/gpio-hlwd.c new file mode 100644 index 000000000..4a17599f6 --- /dev/null +++ b/drivers/gpio/gpio-hlwd.c @@ -0,0 +1,305 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright (C) 2008-2009 The GameCube Linux Team +// Copyright (C) 2008,2009 Albert Herranz +// Copyright (C) 2017-2018 Jonathan Neuschäfer +// +// Nintendo Wii (Hollywood) GPIO driver + +#include <linux/gpio/driver.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/slab.h> + +/* + * Register names and offsets courtesy of WiiBrew: + * https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs + * + * Note that for most registers, there are two versions: + * - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does + * always give access to all GPIO lines + * - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory + * firewall (AHBPROT) in the Hollywood chipset has been configured to allow + * such access. + * + * The ownership of each GPIO line can be configured in the HW_GPIO_OWNER + * register: A one bit configures the line for access via the HW_GPIOB_* + * registers, a zero bit indicates access via HW_GPIO_*. This driver uses + * HW_GPIOB_*. + */ +#define HW_GPIOB_OUT 0x00 +#define HW_GPIOB_DIR 0x04 +#define HW_GPIOB_IN 0x08 +#define HW_GPIOB_INTLVL 0x0c +#define HW_GPIOB_INTFLAG 0x10 +#define HW_GPIOB_INTMASK 0x14 +#define HW_GPIOB_INMIR 0x18 +#define HW_GPIO_ENABLE 0x1c +#define HW_GPIO_OUT 0x20 +#define HW_GPIO_DIR 0x24 +#define HW_GPIO_IN 0x28 +#define HW_GPIO_INTLVL 0x2c +#define HW_GPIO_INTFLAG 0x30 +#define HW_GPIO_INTMASK 0x34 +#define HW_GPIO_INMIR 0x38 +#define HW_GPIO_OWNER 0x3c + +struct hlwd_gpio { + struct gpio_chip gpioc; + struct irq_chip irqc; + void __iomem *regs; + int irq; + u32 edge_emulation; + u32 rising_edge, falling_edge; +}; + +static void hlwd_gpio_irqhandler(struct irq_desc *desc) +{ + struct hlwd_gpio *hlwd = + gpiochip_get_data(irq_desc_get_handler_data(desc)); + struct irq_chip *chip = irq_desc_get_chip(desc); + unsigned long flags; + unsigned long pending; + int hwirq; + u32 emulated_pending; + + spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags); + pending = ioread32be(hlwd->regs + HW_GPIOB_INTFLAG); + pending &= ioread32be(hlwd->regs + HW_GPIOB_INTMASK); + + /* Treat interrupts due to edge trigger emulation separately */ + emulated_pending = hlwd->edge_emulation & pending; + pending &= ~emulated_pending; + if (emulated_pending) { + u32 level, rising, falling; + + level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL); + rising = level & emulated_pending; + falling = ~level & emulated_pending; + + /* Invert the levels */ + iowrite32be(level ^ emulated_pending, + hlwd->regs + HW_GPIOB_INTLVL); + + /* Ack all emulated-edge interrupts */ + iowrite32be(emulated_pending, hlwd->regs + HW_GPIOB_INTFLAG); + + /* Signal interrupts only on the correct edge */ + rising &= hlwd->rising_edge; + falling &= hlwd->falling_edge; + + /* Mark emulated interrupts as pending */ + pending |= rising | falling; + } + spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); + + chained_irq_enter(chip, desc); + + for_each_set_bit(hwirq, &pending, 32) { + int irq = irq_find_mapping(hlwd->gpioc.irq.domain, hwirq); + + generic_handle_irq(irq); + } + + chained_irq_exit(chip, desc); +} + +static void hlwd_gpio_irq_ack(struct irq_data *data) +{ + struct hlwd_gpio *hlwd = + gpiochip_get_data(irq_data_get_irq_chip_data(data)); + + iowrite32be(BIT(data->hwirq), hlwd->regs + HW_GPIOB_INTFLAG); +} + +static void hlwd_gpio_irq_mask(struct irq_data *data) +{ + struct hlwd_gpio *hlwd = + gpiochip_get_data(irq_data_get_irq_chip_data(data)); + unsigned long flags; + u32 mask; + + spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags); + mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK); + mask &= ~BIT(data->hwirq); + iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK); + spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); +} + +static void hlwd_gpio_irq_unmask(struct irq_data *data) +{ + struct hlwd_gpio *hlwd = + gpiochip_get_data(irq_data_get_irq_chip_data(data)); + unsigned long flags; + u32 mask; + + spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags); + mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK); + mask |= BIT(data->hwirq); + iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK); + spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); +} + +static void hlwd_gpio_irq_enable(struct irq_data *data) +{ + hlwd_gpio_irq_ack(data); + hlwd_gpio_irq_unmask(data); +} + +static void hlwd_gpio_irq_setup_emulation(struct hlwd_gpio *hlwd, int hwirq, + unsigned int flow_type) +{ + u32 level, state; + + /* Set the trigger level to the inactive level */ + level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL); + state = ioread32be(hlwd->regs + HW_GPIOB_IN) & BIT(hwirq); + level &= ~BIT(hwirq); + level |= state ^ BIT(hwirq); + iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL); + + hlwd->edge_emulation |= BIT(hwirq); + hlwd->rising_edge &= ~BIT(hwirq); + hlwd->falling_edge &= ~BIT(hwirq); + if (flow_type & IRQ_TYPE_EDGE_RISING) + hlwd->rising_edge |= BIT(hwirq); + if (flow_type & IRQ_TYPE_EDGE_FALLING) + hlwd->falling_edge |= BIT(hwirq); +} + +static int hlwd_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type) +{ + struct hlwd_gpio *hlwd = + gpiochip_get_data(irq_data_get_irq_chip_data(data)); + unsigned long flags; + u32 level; + + spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags); + + hlwd->edge_emulation &= ~BIT(data->hwirq); + + switch (flow_type) { + case IRQ_TYPE_LEVEL_HIGH: + level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL); + level |= BIT(data->hwirq); + iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL); + break; + case IRQ_TYPE_LEVEL_LOW: + level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL); + level &= ~BIT(data->hwirq); + iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL); + break; + case IRQ_TYPE_EDGE_RISING: + case IRQ_TYPE_EDGE_FALLING: + case IRQ_TYPE_EDGE_BOTH: + hlwd_gpio_irq_setup_emulation(hlwd, data->hwirq, flow_type); + break; + default: + spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); + return -EINVAL; + } + + spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); + return 0; +} + +static int hlwd_gpio_probe(struct platform_device *pdev) +{ + struct hlwd_gpio *hlwd; + u32 ngpios; + int res; + + hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL); + if (!hlwd) + return -ENOMEM; + + hlwd->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(hlwd->regs)) + return PTR_ERR(hlwd->regs); + + /* + * Claim all GPIOs using the OWNER register. This will not work on + * systems where the AHBPROT memory firewall hasn't been configured to + * permit PPC access to HW_GPIO_*. + * + * Note that this has to happen before bgpio_init reads the + * HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong + * values. + */ + iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER); + + res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4, + hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT, + NULL, hlwd->regs + HW_GPIOB_DIR, NULL, + BGPIOF_BIG_ENDIAN_BYTE_ORDER); + if (res < 0) { + dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res); + return res; + } + + res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios); + if (res) + ngpios = 32; + hlwd->gpioc.ngpio = ngpios; + + /* Mask and ack all interrupts */ + iowrite32be(0, hlwd->regs + HW_GPIOB_INTMASK); + iowrite32be(0xffffffff, hlwd->regs + HW_GPIOB_INTFLAG); + + /* + * If this GPIO controller is not marked as an interrupt controller in + * the DT, skip interrupt support. + */ + if (of_property_read_bool(pdev->dev.of_node, "interrupt-controller")) { + struct gpio_irq_chip *girq; + + hlwd->irq = platform_get_irq(pdev, 0); + if (hlwd->irq < 0) { + dev_info(&pdev->dev, "platform_get_irq returned %d\n", + hlwd->irq); + return hlwd->irq; + } + + hlwd->irqc.name = dev_name(&pdev->dev); + hlwd->irqc.irq_mask = hlwd_gpio_irq_mask; + hlwd->irqc.irq_unmask = hlwd_gpio_irq_unmask; + hlwd->irqc.irq_enable = hlwd_gpio_irq_enable; + hlwd->irqc.irq_set_type = hlwd_gpio_irq_set_type; + + girq = &hlwd->gpioc.irq; + girq->chip = &hlwd->irqc; + girq->parent_handler = hlwd_gpio_irqhandler; + girq->num_parents = 1; + girq->parents = devm_kcalloc(&pdev->dev, 1, + sizeof(*girq->parents), + GFP_KERNEL); + if (!girq->parents) + return -ENOMEM; + girq->parents[0] = hlwd->irq; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_level_irq; + } + + return devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd); +} + +static const struct of_device_id hlwd_gpio_match[] = { + { .compatible = "nintendo,hollywood-gpio", }, + {}, +}; +MODULE_DEVICE_TABLE(of, hlwd_gpio_match); + +static struct platform_driver hlwd_gpio_driver = { + .driver = { + .name = "gpio-hlwd", + .of_match_table = hlwd_gpio_match, + }, + .probe = hlwd_gpio_probe, +}; +module_platform_driver(hlwd_gpio_driver); + +MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>"); +MODULE_DESCRIPTION("Nintendo Wii GPIO driver"); +MODULE_LICENSE("GPL"); |