diff options
| -rw-r--r-- | drivers/gpio/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/gpio-realtek-otto.c | 325 |
3 files changed, 339 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index e3607ec4c2e8..6fb13d6507db 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -502,6 +502,19 @@ config GPIO_RDA help Say Y here to support RDA Micro GPIO controller. +config GPIO_REALTEK_OTTO + tristate "Realtek Otto GPIO support" + depends on MACH_REALTEK_RTL + default MACH_REALTEK_RTL + select GPIO_GENERIC + select GPIOLIB_IRQCHIP + help + The GPIO controller on the Otto MIPS platform supports up to two + banks of 32 GPIOs, with edge triggered interrupts. The 32 GPIOs + are grouped in four 8-bit wide ports. + + When built as a module, the module will be called realtek_otto_gpio. + config GPIO_REG bool help diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index c58a90a3c3b1..8ace5934e3c3 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -124,6 +124,7 @@ obj-$(CONFIG_GPIO_RC5T583) += gpio-rc5t583.o obj-$(CONFIG_GPIO_RCAR) += gpio-rcar.o obj-$(CONFIG_GPIO_RDA) += gpio-rda.o obj-$(CONFIG_GPIO_RDC321X) += gpio-rdc321x.o +obj-$(CONFIG_GPIO_REALTEK_OTTO) += gpio-realtek-otto.o obj-$(CONFIG_GPIO_REG) += gpio-reg.o obj-$(CONFIG_ARCH_SA1100) += gpio-sa1100.o obj-$(CONFIG_GPIO_SAMA5D2_PIOBU) += gpio-sama5d2-piobu.o diff --git a/drivers/gpio/gpio-realtek-otto.c b/drivers/gpio/gpio-realtek-otto.c new file mode 100644 index 000000000000..cb64fb5a51aa --- /dev/null +++ b/drivers/gpio/gpio-realtek-otto.c @@ -0,0 +1,325 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/gpio/driver.h> +#include <linux/irq.h> +#include <linux/minmax.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +/* + * Total register block size is 0x1C for one bank of four ports (A, B, C, D). + * An optional second bank, with ports E, F, G, and H, may be present, starting + * at register offset 0x1C. + */ + +/* + * Pin select: (0) "normal", (1) "dedicate peripheral" + * Not used on RTL8380/RTL8390, peripheral selection is managed by control bits + * in the peripheral registers. + */ +#define REALTEK_GPIO_REG_CNR 0x00 +/* Clear bit (0) for input, set bit (1) for output */ +#define REALTEK_GPIO_REG_DIR 0x08 +#define REALTEK_GPIO_REG_DATA 0x0C +/* Read bit for IRQ status, write 1 to clear IRQ */ +#define REALTEK_GPIO_REG_ISR 0x10 +/* Two bits per GPIO in IMR registers */ +#define REALTEK_GPIO_REG_IMR 0x14 +#define REALTEK_GPIO_REG_IMR_AB 0x14 +#define REALTEK_GPIO_REG_IMR_CD 0x18 +#define REALTEK_GPIO_IMR_LINE_MASK GENMASK(1, 0) +#define REALTEK_GPIO_IRQ_EDGE_FALLING 1 +#define REALTEK_GPIO_IRQ_EDGE_RISING 2 +#define REALTEK_GPIO_IRQ_EDGE_BOTH 3 + +#define REALTEK_GPIO_MAX 32 +#define REALTEK_GPIO_PORTS_PER_BANK 4 + +/** + * realtek_gpio_ctrl - Realtek Otto GPIO driver data + * + * @gc: Associated gpio_chip instance + * @base: Base address of the register block for a GPIO bank + * @lock: Lock for accessing the IRQ registers and values + * @intr_mask: Mask for interrupts lines + * @intr_type: Interrupt type selection + * + * Because the interrupt mask register (IMR) combines the function of IRQ type + * selection and masking, two extra values are stored. @intr_mask is used to + * mask/unmask the interrupts for a GPIO port, and @intr_type is used to store + * the selected interrupt types. The logical AND of these values is written to + * IMR on changes. + */ +struct realtek_gpio_ctrl { + struct gpio_chip gc; + void __iomem *base; + raw_spinlock_t lock; + u16 intr_mask[REALTEK_GPIO_PORTS_PER_BANK]; + u16 intr_type[REALTEK_GPIO_PORTS_PER_BANK]; +}; + +/* Expand with more flags as devices with other quirks are added */ +enum realtek_gpio_flags { + /* + * Allow disabling interrupts, for cases where the port order is + * unknown. This may result in a port mismatch between ISR and IMR. + * An interrupt would appear to come from a different line than the + * line the IRQ handler was assigned to, causing uncaught interrupts. + */ + GPIO_INTERRUPTS_DISABLED = BIT(0), +}; + +static struct realtek_gpio_ctrl *irq_data_to_ctrl(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + + return container_of(gc, struct realtek_gpio_ctrl, gc); +} + +/* + * Normal port order register access + * + * Port information is stored with the first port at offset 0, followed by the + * second, etc. Most registers store one bit per GPIO and use a u8 value per + * port. The two interrupt mask registers store two bits per GPIO, so use u16 + * values. + */ +static void realtek_gpio_write_imr(struct realtek_gpio_ctrl *ctrl, + unsigned int port, u16 irq_type, u16 irq_mask) +{ + iowrite16(irq_type & irq_mask, ctrl->base + REALTEK_GPIO_REG_IMR + 2 * port); +} + +static void realtek_gpio_clear_isr(struct realtek_gpio_ctrl *ctrl, + unsigned int port, u8 mask) +{ + iowrite8(mask, ctrl->base + REALTEK_GPIO_REG_ISR + port); +} + +static u8 realtek_gpio_read_isr(struct realtek_gpio_ctrl *ctrl, unsigned int port) +{ + return ioread8(ctrl->base + REALTEK_GPIO_REG_ISR + port); +} + +/* Set the rising and falling edge mask bits for a GPIO port pin */ +static u16 realtek_gpio_imr_bits(unsigned int pin, u16 value) +{ + return (value & REALTEK_GPIO_IMR_LINE_MASK) << 2 * pin; +} + +static void realtek_gpio_irq_ack(struct irq_data *data) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + irq_hw_number_t line = irqd_to_hwirq(data); + unsigned int port = line / 8; + unsigned int port_pin = line % 8; + + realtek_gpio_clear_isr(ctrl, port, BIT(port_pin)); +} + +static void realtek_gpio_irq_unmask(struct irq_data *data) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + unsigned int port = line / 8; + unsigned int port_pin = line % 8; + unsigned long flags; + u16 m; + + raw_spin_lock_irqsave(&ctrl->lock, flags); + m = ctrl->intr_mask[port]; + m |= realtek_gpio_imr_bits(port_pin, REALTEK_GPIO_IMR_LINE_MASK); + ctrl->intr_mask[port] = m; + realtek_gpio_write_imr(ctrl, port, ctrl->intr_type[port], m); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); +} + +static void realtek_gpio_irq_mask(struct irq_data *data) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + unsigned int port = line / 8; + unsigned int port_pin = line % 8; + unsigned long flags; + u16 m; + + raw_spin_lock_irqsave(&ctrl->lock, flags); + m = ctrl->intr_mask[port]; + m &= ~realtek_gpio_imr_bits(port_pin, REALTEK_GPIO_IMR_LINE_MASK); + ctrl->intr_mask[port] = m; + realtek_gpio_write_imr(ctrl, port, ctrl->intr_type[port], m); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); +} + +static int realtek_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + unsigned int port = line / 8; + unsigned int port_pin = line % 8; + unsigned long flags; + u16 type, t; + + switch (flow_type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_FALLING: + type = REALTEK_GPIO_IRQ_EDGE_FALLING; + break; + case IRQ_TYPE_EDGE_RISING: + type = REALTEK_GPIO_IRQ_EDGE_RISING; + break; + case IRQ_TYPE_EDGE_BOTH: + type = REALTEK_GPIO_IRQ_EDGE_BOTH; + break; + default: + return -EINVAL; + } + + irq_set_handler_locked(data, handle_edge_irq); + + raw_spin_lock_irqsave(&ctrl->lock, flags); + t = ctrl->intr_type[port]; + t &= ~realtek_gpio_imr_bits(port_pin, REALTEK_GPIO_IMR_LINE_MASK); + t |= realtek_gpio_imr_bits(port_pin, type); + ctrl->intr_type[port] = t; + realtek_gpio_write_imr(ctrl, port, t, ctrl->intr_mask[port]); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); + + return 0; +} + +static void realtek_gpio_irq_handler(struct irq_desc *desc) +{ + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct realtek_gpio_ctrl *ctrl = gpiochip_get_data(gc); + struct irq_chip *irq_chip = irq_desc_get_chip(desc); + unsigned int lines_done; + unsigned int port_pin_count; + unsigned int irq; + unsigned long status; + int offset; + + chained_irq_enter(irq_chip, desc); + + for (lines_done = 0; lines_done < gc->ngpio; lines_done += 8) { + status = realtek_gpio_read_isr(ctrl, lines_done / 8); + port_pin_count = min(gc->ngpio - lines_done, 8U); + for_each_set_bit(offset, &status, port_pin_count) { + irq = irq_find_mapping(gc->irq.domain, offset); + generic_handle_irq(irq); + } + } + + chained_irq_exit(irq_chip, desc); +} + +static int realtek_gpio_irq_init(struct gpio_chip *gc) +{ + struct realtek_gpio_ctrl *ctrl = gpiochip_get_data(gc); + unsigned int port; + + for (port = 0; (port * 8) < gc->ngpio; port++) { + realtek_gpio_write_imr(ctrl, port, 0, 0); + realtek_gpio_clear_isr(ctrl, port, GENMASK(7, 0)); + } + + return 0; +} + +static struct irq_chip realtek_gpio_irq_chip = { + .name = "realtek-otto-gpio", + .irq_ack = realtek_gpio_irq_ack, + .irq_mask = realtek_gpio_irq_mask, + .irq_unmask = realtek_gpio_irq_unmask, + .irq_set_type = realtek_gpio_irq_set_type, +}; + +static const struct of_device_id realtek_gpio_of_match[] = { + { + .compatible = "realtek,otto-gpio", + .data = (void *)GPIO_INTERRUPTS_DISABLED, + }, + { + .compatible = "realtek,rtl8380-gpio", + }, + { + .compatible = "realtek,rtl8390-gpio", + }, + {} +}; +MODULE_DEVICE_TABLE(of, realtek_gpio_of_match); + +static int realtek_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + unsigned int dev_flags; + struct gpio_irq_chip *girq; + struct realtek_gpio_ctrl *ctrl; + u32 ngpios; + int err, irq; + + ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL); + if (!ctrl) + return -ENOMEM; + + dev_flags = (unsigned int) device_get_match_data(dev); + + ngpios = REALTEK_GPIO_MAX; + device_property_read_u32(dev, "ngpios", &ngpios); + + if (ngpios > REALTEK_GPIO_MAX) { + dev_err(&pdev->dev, "invalid ngpios (max. %d)\n", + REALTEK_GPIO_MAX); + return -EINVAL; + } + + ctrl->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ctrl->base)) + return PTR_ERR(ctrl->base); + + raw_spin_lock_init(&ctrl->lock); + + err = bgpio_init(&ctrl->gc, dev, 4, + ctrl->base + REALTEK_GPIO_REG_DATA, NULL, NULL, + ctrl->base + REALTEK_GPIO_REG_DIR, NULL, + BGPIOF_BIG_ENDIAN_BYTE_ORDER); + if (err) { + dev_err(dev, "unable to init generic GPIO"); + return err; + } + + ctrl->gc.ngpio = ngpios; + ctrl->gc.owner = THIS_MODULE; + + irq = platform_get_irq_optional(pdev, 0); + if (!(dev_flags & GPIO_INTERRUPTS_DISABLED) && irq > 0) { + girq = &ctrl->gc.irq; + girq->chip = &realtek_gpio_irq_chip; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_bad_irq; + girq->parent_handler = realtek_gpio_irq_handler; + girq->num_parents = 1; + girq->parents = devm_kcalloc(dev, girq->num_parents, + sizeof(*girq->parents), GFP_KERNEL); + if (!girq->parents) + return -ENOMEM; + girq->parents[0] = irq; + girq->init_hw = realtek_gpio_irq_init; + } + + return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl); +} + +static struct platform_driver realtek_gpio_driver = { + .driver = { + .name = "realtek-otto-gpio", + .of_match_table = realtek_gpio_of_match, + }, + .probe = realtek_gpio_probe, +}; +module_platform_driver(realtek_gpio_driver); + +MODULE_DESCRIPTION("Realtek Otto GPIO support"); +MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>"); +MODULE_LICENSE("GPL v2"); |