@@ -502,6 +502,17 @@ config GPIO_RDA
help
Say Y here to support RDA Micro GPIO controller.
+config GPIO_REALTEK_OTTO
+ bool "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.
+
config GPIO_REG
bool
help
@@ -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
new file mode 100644
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/gpio/driver.h>
+#include <linux/irq.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/swab.h>
+
+/*
+ * Total register block size is 0x1C for four ports.
+ * On the RTL8380/RLT8390 platforms port A, B, and C are implemented.
+ * RTL8389 and RTL8328 implement a second bank with ports E, F, G, and H.
+ *
+ * Port information is stored with the first port at offset 0, followed by the
+ * second, etc. Most registers store one bit per GPIO and should be read out in
+ * reversed endian order. The two interrupt mask registers store two bits per
+ * GPIO, and should be manipulated with swahw32, if required.
+ */
+
+/*
+ * 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 driver data
+ * 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 certain GPIO,
+ * and intr_type is used to store the selected interrupt types. The
+ * logical AND of these values is written to IMR on changes.
+ *
+ * @gc Associated gpio_chip instance
+ * @base Base address of the register block
+ * @lock Lock for accessing the IRQ registers and values
+ * @intr_mask Mask for GPIO interrupts
+ * @intr_type GPIO interrupt type selection
+ */
+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];
+};
+
+enum realtek_gpio_flags {
+ GPIO_INTERRUPTS = 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);
+}
+
+static inline unsigned int line_to_port(unsigned int line)
+{
+ return line / 8;
+}
+
+static inline unsigned int line_to_port_pin(unsigned int line)
+{
+ return line % 8;
+}
+
+static inline u8 read_u8_reg(void __iomem* reg, unsigned int port)
+{
+ return ioread8(reg + port);
+}
+
+static inline void write_u8_reg(void __iomem* reg, unsigned int port, u8 value)
+{
+ iowrite8(value, reg + port);
+}
+
+static inline u16 read_u16_reg(void __iomem* reg, unsigned int port)
+{
+ return ioread16(reg + 2 * port);
+}
+
+static inline void write_u16_reg(void __iomem* reg, unsigned int port, u16 value)
+{
+ iowrite16(value, reg + 2 * port);
+}
+
+/*
+ * Since the IMRs contain two bits per GPIO, only 16 GPIO lines fit in a 32-bit
+ * register. Use realtek_gpio_imr_bits() to put the GPIO line's new value in
+ * the right place.
+ */
+static inline u16 realtek_gpio_imr_bits(unsigned int pin, u16 value)
+{
+ return (value & REALTEK_GPIO_IMR_LINE_MASK) << 2 * pin;
+}
+
+static inline void realtek_gpio_write_imr(struct realtek_gpio_ctrl *ctrl,
+ unsigned int port, u16 irq_type, u16 irq_mask)
+{
+ write_u16_reg(ctrl->base + REALTEK_GPIO_REG_IMR, port,
+ irq_type & irq_mask);
+}
+
+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);
+
+ write_u8_reg(ctrl->base + REALTEK_GPIO_REG_ISR, line_to_port(line),
+ BIT(line_to_port_pin(line)));
+}
+
+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_to_port(line);
+ unsigned int pin = line_to_port_pin(line);
+ unsigned long flags;
+ u16 m;
+
+ raw_spin_lock_irqsave(&ctrl->lock, flags);
+ m = ctrl->intr_mask[port];
+ m |= realtek_gpio_imr_bits(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_to_port(line);
+ unsigned int pin = line_to_port_pin(line);
+ unsigned long flags;
+ u16 m;
+
+ raw_spin_lock_irqsave(&ctrl->lock, flags);
+ m = ctrl->intr_mask[port];
+ m &= ~realtek_gpio_imr_bits(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_to_port(line);
+ unsigned int pin = line_to_port_pin(line);
+ 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(pin, REALTEK_GPIO_IMR_LINE_MASK);
+ t |= realtek_gpio_imr_bits(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);
+ void __iomem *reg_isr = ctrl->base + REALTEK_GPIO_REG_ISR;
+ unsigned int lines_done;
+ unsigned int port_pin_count;
+ unsigned int port;
+ unsigned int irq;
+ int offset;
+ unsigned long status;
+
+ chained_irq_enter(irq_chip, desc);
+
+ for (lines_done = 0; lines_done < gc->ngpio; lines_done += 8) {
+ port = line_to_port(lines_done);
+ status = read_u8_reg(reg_isr, port);
+ port_pin_count = min(gc->ngpio - lines_done, (unsigned int) 8);
+ for_each_set_bit(offset, &status, port_pin_count) {
+ irq = irq_find_mapping(gc->irq.domain, offset);
+ generic_handle_irq(irq);
+ write_u8_reg(reg_isr, port, BIT(offset));
+ }
+ }
+
+ chained_irq_exit(irq_chip, desc);
+}
+
+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" },
+ {
+ .compatible = "realtek,rtl8380-gpio",
+ .data = (void *)GPIO_INTERRUPTS
+ },
+ {
+ .compatible = "realtek,rtl8390-gpio",
+ .data = (void *)GPIO_INTERRUPTS
+ },
+ {}
+};
+
+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);
+
+ if (device_property_read_u32(dev, "ngpios", &ngpios))
+ ngpios = REALTEK_GPIO_MAX;
+
+ 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) && irq > 0) {
+ girq = &ctrl->gc.irq;
+ girq->chip = &realtek_gpio_irq_chip;
+ 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->default_type = IRQ_TYPE_NONE;
+ girq->handler = handle_bad_irq;
+ girq->parents[0] = irq;
+
+ /* Disable and clear all interrupts */
+ iowrite32(0, ctrl->base + REALTEK_GPIO_REG_IMR_AB);
+ iowrite32(0, ctrl->base + REALTEK_GPIO_REG_IMR_CD);
+ iowrite32(GENMASK(31, 0), ctrl->base + REALTEK_GPIO_REG_ISR);
+ }
+
+ return gpiochip_add_data(&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,
+};
+
+builtin_platform_driver(realtek_gpio_driver);
+
+MODULE_DESCRIPTION("Realtek Otto GPIO support");
+MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>");
+MODULE_LICENSE("GPL v2");