--- /dev/null
+/*
+ * Generic EP93xx GPIO handling
+ *
+ * Copyright (c) 2008 Ryan Mallon
+ * Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *
+ * Based on code originally from:
+ * linux/arch/arm/mach-ep93xx/core.c
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/basic_mmio_gpio.h>
+
+#include <mach/hardware.h>
+#include <mach/gpio-ep93xx.h>
+
+#define irq_to_gpio(irq) ((irq) - gpio_to_irq(0))
+
+struct ep93xx_gpio {
+ void __iomem *mmio_base;
+ struct bgpio_chip bgc[8];
+};
+
+/*************************************************************************
+ * Interrupt handling for EP93xx on-chip GPIOs
+ *************************************************************************/
+static unsigned char gpio_int_unmasked[3];
+static unsigned char gpio_int_enabled[3];
+static unsigned char gpio_int_type1[3];
+static unsigned char gpio_int_type2[3];
+static unsigned char gpio_int_debounce[3];
+
+/* Port ordering is: A B F */
+static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
+static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
+static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
+static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 };
+static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
+
+static void ep93xx_gpio_update_int_params(unsigned port)
+{
+ BUG_ON(port > 2);
+
+ writeb_relaxed(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
+
+ writeb_relaxed(gpio_int_type2[port],
+ EP93XX_GPIO_REG(int_type2_register_offset[port]));
+
+ writeb_relaxed(gpio_int_type1[port],
+ EP93XX_GPIO_REG(int_type1_register_offset[port]));
+
+ writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
+ EP93XX_GPIO_REG(int_en_register_offset[port]));
+}
+
+static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
+{
+ int line = irq_to_gpio(irq);
+ int port = line >> 3;
+ int port_mask = 1 << (line & 7);
+
+ if (enable)
+ gpio_int_debounce[port] |= port_mask;
+ else
+ gpio_int_debounce[port] &= ~port_mask;
+
+ writeb(gpio_int_debounce[port],
+ EP93XX_GPIO_REG(int_debounce_register_offset[port]));
+}
+
+static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+ unsigned char status;
+ int i;
+
+ status = readb(EP93XX_GPIO_A_INT_STATUS);
+ for (i = 0; i < 8; i++) {
+ if (status & (1 << i)) {
+ int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
+ generic_handle_irq(gpio_irq);
+ }
+ }
+
+ status = readb(EP93XX_GPIO_B_INT_STATUS);
+ for (i = 0; i < 8; i++) {
+ if (status & (1 << i)) {
+ int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
+ generic_handle_irq(gpio_irq);
+ }
+ }
+}
+
+static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+ /*
+ * map discontiguous hw irq range to continuous sw irq range:
+ *
+ * IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
+ */
+ int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
+ int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
+
+ generic_handle_irq(gpio_irq);
+}
+
+static void ep93xx_gpio_irq_ack(struct irq_data *d)
+{
+ int line = irq_to_gpio(d->irq);
+ int port = line >> 3;
+ int port_mask = 1 << (line & 7);
+
+ if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
+ gpio_int_type2[port] ^= port_mask; /* switch edge direction */
+ ep93xx_gpio_update_int_params(port);
+ }
+
+ writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
+}
+
+static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
+{
+ int line = irq_to_gpio(d->irq);
+ int port = line >> 3;
+ int port_mask = 1 << (line & 7);
+
+ if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
+ gpio_int_type2[port] ^= port_mask; /* switch edge direction */
+
+ gpio_int_unmasked[port] &= ~port_mask;
+ ep93xx_gpio_update_int_params(port);
+
+ writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
+}
+
+static void ep93xx_gpio_irq_mask(struct irq_data *d)
+{
+ int line = irq_to_gpio(d->irq);
+ int port = line >> 3;
+
+ gpio_int_unmasked[port] &= ~(1 << (line & 7));
+ ep93xx_gpio_update_int_params(port);
+}
+
+static void ep93xx_gpio_irq_unmask(struct irq_data *d)
+{
+ int line = irq_to_gpio(d->irq);
+ int port = line >> 3;
+
+ gpio_int_unmasked[port] |= 1 << (line & 7);
+ ep93xx_gpio_update_int_params(port);
+}
+
+/*
+ * gpio_int_type1 controls whether the interrupt is level (0) or
+ * edge (1) triggered, while gpio_int_type2 controls whether it
+ * triggers on low/falling (0) or high/rising (1).
+ */
+static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
+{
+ const int gpio = irq_to_gpio(d->irq);
+ const int port = gpio >> 3;
+ const int port_mask = 1 << (gpio & 7);
+ irq_flow_handler_t handler;
+
+ gpio_direction_input(gpio);
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_RISING:
+ gpio_int_type1[port] |= port_mask;
+ gpio_int_type2[port] |= port_mask;
+ handler = handle_edge_irq;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ gpio_int_type1[port] |= port_mask;
+ gpio_int_type2[port] &= ~port_mask;
+ handler = handle_edge_irq;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ gpio_int_type1[port] &= ~port_mask;
+ gpio_int_type2[port] |= port_mask;
+ handler = handle_level_irq;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ gpio_int_type1[port] &= ~port_mask;
+ gpio_int_type2[port] &= ~port_mask;
+ handler = handle_level_irq;
+ break;
+ case IRQ_TYPE_EDGE_BOTH:
+ gpio_int_type1[port] |= port_mask;
+ /* set initial polarity based on current input level */
+ if (gpio_get_value(gpio))
+ gpio_int_type2[port] &= ~port_mask; /* falling */
+ else
+ gpio_int_type2[port] |= port_mask; /* rising */
+ handler = handle_edge_irq;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ __irq_set_handler_locked(d->irq, handler);
+
+ gpio_int_enabled[port] |= port_mask;
+
+ ep93xx_gpio_update_int_params(port);
+
+ return 0;
+}
+
+static struct irq_chip ep93xx_gpio_irq_chip = {
+ .name = "GPIO",
+ .irq_ack = ep93xx_gpio_irq_ack,
+ .irq_mask_ack = ep93xx_gpio_irq_mask_ack,
+ .irq_mask = ep93xx_gpio_irq_mask,
+ .irq_unmask = ep93xx_gpio_irq_unmask,
+ .irq_set_type = ep93xx_gpio_irq_type,
+};
+
+static void ep93xx_gpio_init_irq(void)
+{
+ int gpio_irq;
+
+ for (gpio_irq = gpio_to_irq(0);
+ gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
+ irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
+ handle_level_irq);
+ set_irq_flags(gpio_irq, IRQF_VALID);
+ }
+
+ irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
+ ep93xx_gpio_ab_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
+ ep93xx_gpio_f_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
+ ep93xx_gpio_f_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
+ ep93xx_gpio_f_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
+ ep93xx_gpio_f_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
+ ep93xx_gpio_f_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
+ ep93xx_gpio_f_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
+ ep93xx_gpio_f_irq_handler);
+ irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
+ ep93xx_gpio_f_irq_handler);
+}
+
+
+/*************************************************************************
+ * gpiolib interface for EP93xx on-chip GPIOs
+ *************************************************************************/
+struct ep93xx_gpio_bank {
+ const char *label;
+ int data;
+ int dir;
+ int base;
+ bool has_debounce;
+};
+
+#define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \
+ { \
+ .label = _label, \
+ .data = _data, \
+ .dir = _dir, \
+ .base = _base, \
+ .has_debounce = _debounce, \
+ }
+
+static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
+ EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true),
+ EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true),
+ EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false),
+ EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false),
+ EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false),
+ EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true),
+ EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false),
+ EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false),
+};
+
+static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
+ unsigned offset, unsigned debounce)
+{
+ int gpio = chip->base + offset;
+ int irq = gpio_to_irq(gpio);
+
+ if (irq < 0)
+ return -EINVAL;
+
+ ep93xx_gpio_int_debounce(irq, debounce ? true : false);
+
+ return 0;
+}
+
+/*
+ * Map GPIO A0..A7 (0..7) to irq 64..71,
+ * B0..B7 (7..15) to irq 72..79, and
+ * F0..F7 (16..24) to irq 80..87.
+ */
+static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ int gpio = chip->base + offset;
+
+ if (gpio > EP93XX_GPIO_LINE_MAX_IRQ)
+ return -EINVAL;
+
+ return 64 + gpio;
+}
+
+static int ep93xx_gpio_add_bank(struct bgpio_chip *bgc, struct device *dev,
+ void __iomem *mmio_base, struct ep93xx_gpio_bank *bank)
+{
+ void __iomem *data = mmio_base + bank->data;
+ void __iomem *dir = mmio_base + bank->dir;
+ int err;
+
+ err = bgpio_init(bgc, dev, 1, data, NULL, NULL, dir, NULL, 0);
+ if (err)
+ return err;
+
+ bgc->gc.label = bank->label;
+ bgc->gc.base = bank->base;
+
+ if (bank->has_debounce) {
+ bgc->gc.set_debounce = ep93xx_gpio_set_debounce;
+ bgc->gc.to_irq = ep93xx_gpio_to_irq;
+ }
+
+ return gpiochip_add(&bgc->gc);
+}
+
+static int ep93xx_gpio_probe(struct platform_device *pdev)
+{
+ struct ep93xx_gpio *ep93xx_gpio;
+ struct resource *res;
+ int i;
+ struct device *dev = &pdev->dev;
+
+ ep93xx_gpio = devm_kzalloc(dev, sizeof(struct ep93xx_gpio), GFP_KERNEL);
+ if (!ep93xx_gpio)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ep93xx_gpio->mmio_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(ep93xx_gpio->mmio_base))
+ return PTR_ERR(ep93xx_gpio->mmio_base);
+
+ for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
+ struct bgpio_chip *bgc = &ep93xx_gpio->bgc[i];
+ struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
+
+ if (ep93xx_gpio_add_bank(bgc, &pdev->dev,
+ ep93xx_gpio->mmio_base, bank))
+ dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
+ bank->label);
+ }
+
+ ep93xx_gpio_init_irq();
+
+ return 0;
+}
+
+static struct platform_driver ep93xx_gpio_driver = {
+ .driver = {
+ .name = "gpio-ep93xx",
+ },
+ .probe = ep93xx_gpio_probe,
+};
+
+static int __init ep93xx_gpio_init(void)
+{
+ return platform_driver_register(&ep93xx_gpio_driver);
+}
+postcore_initcall(ep93xx_gpio_init);
+
+MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
+ "H Hartley Sweeten <hsweeten@visionengravers.com>");
+MODULE_DESCRIPTION("EP93XX GPIO driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff