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path: root/drivers/gpio/gpio-ep93xx.c
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-rw-r--r--drivers/gpio/gpio-ep93xx.c467
1 files changed, 467 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ep93xx.c b/drivers/gpio/gpio-ep93xx.c
new file mode 100644
index 0000000000..6cedf46efe
--- /dev/null
+++ b/drivers/gpio/gpio-ep93xx.c
@@ -0,0 +1,467 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/gpio/driver.h>
+#include <linux/bitops.h>
+#include <linux/seq_file.h>
+
+#define EP93XX_GPIO_F_INT_STATUS 0x5c
+#define EP93XX_GPIO_A_INT_STATUS 0xa0
+#define EP93XX_GPIO_B_INT_STATUS 0xbc
+
+/* Maximum value for gpio line identifiers */
+#define EP93XX_GPIO_LINE_MAX 63
+
+/* Number of GPIO chips in EP93XX */
+#define EP93XX_GPIO_CHIP_NUM 8
+
+/* Maximum value for irq capable line identifiers */
+#define EP93XX_GPIO_LINE_MAX_IRQ 23
+
+#define EP93XX_GPIO_A_IRQ_BASE 64
+#define EP93XX_GPIO_B_IRQ_BASE 72
+/*
+ * Static mapping of GPIO bank F IRQS:
+ * F0..F7 (16..24) to irq 80..87.
+ */
+#define EP93XX_GPIO_F_IRQ_BASE 80
+
+struct ep93xx_gpio_irq_chip {
+ u8 irq_offset;
+ u8 int_unmasked;
+ u8 int_enabled;
+ u8 int_type1;
+ u8 int_type2;
+ u8 int_debounce;
+};
+
+struct ep93xx_gpio_chip {
+ struct gpio_chip gc;
+ struct ep93xx_gpio_irq_chip *eic;
+};
+
+struct ep93xx_gpio {
+ void __iomem *base;
+ struct ep93xx_gpio_chip gc[EP93XX_GPIO_CHIP_NUM];
+};
+
+#define to_ep93xx_gpio_chip(x) container_of(x, struct ep93xx_gpio_chip, gc)
+
+static struct ep93xx_gpio_irq_chip *to_ep93xx_gpio_irq_chip(struct gpio_chip *gc)
+{
+ struct ep93xx_gpio_chip *egc = to_ep93xx_gpio_chip(gc);
+
+ return egc->eic;
+}
+
+/*************************************************************************
+ * Interrupt handling for EP93xx on-chip GPIOs
+ *************************************************************************/
+#define EP93XX_INT_TYPE1_OFFSET 0x00
+#define EP93XX_INT_TYPE2_OFFSET 0x04
+#define EP93XX_INT_EOI_OFFSET 0x08
+#define EP93XX_INT_EN_OFFSET 0x0c
+#define EP93XX_INT_STATUS_OFFSET 0x10
+#define EP93XX_INT_RAW_STATUS_OFFSET 0x14
+#define EP93XX_INT_DEBOUNCE_OFFSET 0x18
+
+static void ep93xx_gpio_update_int_params(struct ep93xx_gpio *epg,
+ struct ep93xx_gpio_irq_chip *eic)
+{
+ writeb_relaxed(0, epg->base + eic->irq_offset + EP93XX_INT_EN_OFFSET);
+
+ writeb_relaxed(eic->int_type2,
+ epg->base + eic->irq_offset + EP93XX_INT_TYPE2_OFFSET);
+
+ writeb_relaxed(eic->int_type1,
+ epg->base + eic->irq_offset + EP93XX_INT_TYPE1_OFFSET);
+
+ writeb_relaxed(eic->int_unmasked & eic->int_enabled,
+ epg->base + eic->irq_offset + EP93XX_INT_EN_OFFSET);
+}
+
+static void ep93xx_gpio_int_debounce(struct gpio_chip *gc,
+ unsigned int offset, bool enable)
+{
+ struct ep93xx_gpio *epg = gpiochip_get_data(gc);
+ struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
+ int port_mask = BIT(offset);
+
+ if (enable)
+ eic->int_debounce |= port_mask;
+ else
+ eic->int_debounce &= ~port_mask;
+
+ writeb(eic->int_debounce,
+ epg->base + eic->irq_offset + EP93XX_INT_DEBOUNCE_OFFSET);
+}
+
+static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
+{
+ struct gpio_chip *gc = irq_desc_get_handler_data(desc);
+ struct ep93xx_gpio *epg = gpiochip_get_data(gc);
+ struct irq_chip *irqchip = irq_desc_get_chip(desc);
+ unsigned long stat;
+ int offset;
+
+ chained_irq_enter(irqchip, desc);
+
+ /*
+ * Dispatch the IRQs to the irqdomain of each A and B
+ * gpiochip irqdomains depending on what has fired.
+ * The tricky part is that the IRQ line is shared
+ * between bank A and B and each has their own gpiochip.
+ */
+ stat = readb(epg->base + EP93XX_GPIO_A_INT_STATUS);
+ for_each_set_bit(offset, &stat, 8)
+ generic_handle_domain_irq(epg->gc[0].gc.irq.domain,
+ offset);
+
+ stat = readb(epg->base + EP93XX_GPIO_B_INT_STATUS);
+ for_each_set_bit(offset, &stat, 8)
+ generic_handle_domain_irq(epg->gc[1].gc.irq.domain,
+ offset);
+
+ chained_irq_exit(irqchip, desc);
+}
+
+static void ep93xx_gpio_f_irq_handler(struct irq_desc *desc)
+{
+ /*
+ * map discontiguous hw irq range to continuous sw irq range:
+ *
+ * IRQ_EP93XX_GPIO{0..7}MUX -> EP93XX_GPIO_LINE_F{0..7}
+ */
+ struct irq_chip *irqchip = irq_desc_get_chip(desc);
+ unsigned int irq = irq_desc_get_irq(desc);
+ int port_f_idx = (irq & 7) ^ 4; /* {20..23,48..51} -> {0..7} */
+ int gpio_irq = EP93XX_GPIO_F_IRQ_BASE + port_f_idx;
+
+ chained_irq_enter(irqchip, desc);
+ generic_handle_irq(gpio_irq);
+ chained_irq_exit(irqchip, desc);
+}
+
+static void ep93xx_gpio_irq_ack(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
+ struct ep93xx_gpio *epg = gpiochip_get_data(gc);
+ int port_mask = BIT(d->irq & 7);
+
+ if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
+ eic->int_type2 ^= port_mask; /* switch edge direction */
+ ep93xx_gpio_update_int_params(epg, eic);
+ }
+
+ writeb(port_mask, epg->base + eic->irq_offset + EP93XX_INT_EOI_OFFSET);
+}
+
+static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
+ struct ep93xx_gpio *epg = gpiochip_get_data(gc);
+ int port_mask = BIT(d->irq & 7);
+
+ if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
+ eic->int_type2 ^= port_mask; /* switch edge direction */
+
+ eic->int_unmasked &= ~port_mask;
+ ep93xx_gpio_update_int_params(epg, eic);
+
+ writeb(port_mask, epg->base + eic->irq_offset + EP93XX_INT_EOI_OFFSET);
+ gpiochip_disable_irq(gc, irqd_to_hwirq(d));
+}
+
+static void ep93xx_gpio_irq_mask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
+ struct ep93xx_gpio *epg = gpiochip_get_data(gc);
+
+ eic->int_unmasked &= ~BIT(d->irq & 7);
+ ep93xx_gpio_update_int_params(epg, eic);
+ gpiochip_disable_irq(gc, irqd_to_hwirq(d));
+}
+
+static void ep93xx_gpio_irq_unmask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
+ struct ep93xx_gpio *epg = gpiochip_get_data(gc);
+
+ gpiochip_enable_irq(gc, irqd_to_hwirq(d));
+ eic->int_unmasked |= BIT(d->irq & 7);
+ ep93xx_gpio_update_int_params(epg, eic);
+}
+
+/*
+ * 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)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ep93xx_gpio_irq_chip *eic = to_ep93xx_gpio_irq_chip(gc);
+ struct ep93xx_gpio *epg = gpiochip_get_data(gc);
+ int offset = d->irq & 7;
+ int port_mask = BIT(offset);
+ irq_flow_handler_t handler;
+
+ gc->direction_input(gc, offset);
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_RISING:
+ eic->int_type1 |= port_mask;
+ eic->int_type2 |= port_mask;
+ handler = handle_edge_irq;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ eic->int_type1 |= port_mask;
+ eic->int_type2 &= ~port_mask;
+ handler = handle_edge_irq;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ eic->int_type1 &= ~port_mask;
+ eic->int_type2 |= port_mask;
+ handler = handle_level_irq;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ eic->int_type1 &= ~port_mask;
+ eic->int_type2 &= ~port_mask;
+ handler = handle_level_irq;
+ break;
+ case IRQ_TYPE_EDGE_BOTH:
+ eic->int_type1 |= port_mask;
+ /* set initial polarity based on current input level */
+ if (gc->get(gc, offset))
+ eic->int_type2 &= ~port_mask; /* falling */
+ else
+ eic->int_type2 |= port_mask; /* rising */
+ handler = handle_edge_irq;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ irq_set_handler_locked(d, handler);
+
+ eic->int_enabled |= port_mask;
+
+ ep93xx_gpio_update_int_params(epg, eic);
+
+ return 0;
+}
+
+/*************************************************************************
+ * gpiolib interface for EP93xx on-chip GPIOs
+ *************************************************************************/
+struct ep93xx_gpio_bank {
+ const char *label;
+ int data;
+ int dir;
+ int irq;
+ int base;
+ bool has_irq;
+ bool has_hierarchical_irq;
+ unsigned int irq_base;
+};
+
+#define EP93XX_GPIO_BANK(_label, _data, _dir, _irq, _base, _has_irq, _has_hier, _irq_base) \
+ { \
+ .label = _label, \
+ .data = _data, \
+ .dir = _dir, \
+ .irq = _irq, \
+ .base = _base, \
+ .has_irq = _has_irq, \
+ .has_hierarchical_irq = _has_hier, \
+ .irq_base = _irq_base, \
+ }
+
+static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
+ /* Bank A has 8 IRQs */
+ EP93XX_GPIO_BANK("A", 0x00, 0x10, 0x90, 0, true, false, EP93XX_GPIO_A_IRQ_BASE),
+ /* Bank B has 8 IRQs */
+ EP93XX_GPIO_BANK("B", 0x04, 0x14, 0xac, 8, true, false, EP93XX_GPIO_B_IRQ_BASE),
+ EP93XX_GPIO_BANK("C", 0x08, 0x18, 0x00, 40, false, false, 0),
+ EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 0x00, 24, false, false, 0),
+ EP93XX_GPIO_BANK("E", 0x20, 0x24, 0x00, 32, false, false, 0),
+ /* Bank F has 8 IRQs */
+ EP93XX_GPIO_BANK("F", 0x30, 0x34, 0x4c, 16, false, true, EP93XX_GPIO_F_IRQ_BASE),
+ EP93XX_GPIO_BANK("G", 0x38, 0x3c, 0x00, 48, false, false, 0),
+ EP93XX_GPIO_BANK("H", 0x40, 0x44, 0x00, 56, false, false, 0),
+};
+
+static int ep93xx_gpio_set_config(struct gpio_chip *gc, unsigned offset,
+ unsigned long config)
+{
+ u32 debounce;
+
+ if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
+ return -ENOTSUPP;
+
+ debounce = pinconf_to_config_argument(config);
+ ep93xx_gpio_int_debounce(gc, offset, debounce ? true : false);
+
+ return 0;
+}
+
+static void ep93xx_irq_print_chip(struct irq_data *data, struct seq_file *p)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
+
+ seq_printf(p, dev_name(gc->parent));
+}
+
+static const struct irq_chip gpio_eic_irq_chip = {
+ .name = "ep93xx-gpio-eic",
+ .irq_ack = ep93xx_gpio_irq_ack,
+ .irq_mask = ep93xx_gpio_irq_mask,
+ .irq_unmask = ep93xx_gpio_irq_unmask,
+ .irq_mask_ack = ep93xx_gpio_irq_mask_ack,
+ .irq_set_type = ep93xx_gpio_irq_type,
+ .irq_print_chip = ep93xx_irq_print_chip,
+ .flags = IRQCHIP_IMMUTABLE,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static int ep93xx_gpio_add_bank(struct ep93xx_gpio_chip *egc,
+ struct platform_device *pdev,
+ struct ep93xx_gpio *epg,
+ struct ep93xx_gpio_bank *bank)
+{
+ void __iomem *data = epg->base + bank->data;
+ void __iomem *dir = epg->base + bank->dir;
+ struct gpio_chip *gc = &egc->gc;
+ struct device *dev = &pdev->dev;
+ struct gpio_irq_chip *girq;
+ int err;
+
+ err = bgpio_init(gc, dev, 1, data, NULL, NULL, dir, NULL, 0);
+ if (err)
+ return err;
+
+ gc->label = bank->label;
+ gc->base = bank->base;
+
+ girq = &gc->irq;
+ if (bank->has_irq || bank->has_hierarchical_irq) {
+ gc->set_config = ep93xx_gpio_set_config;
+ egc->eic = devm_kcalloc(dev, 1,
+ sizeof(*egc->eic),
+ GFP_KERNEL);
+ if (!egc->eic)
+ return -ENOMEM;
+ egc->eic->irq_offset = bank->irq;
+ gpio_irq_chip_set_chip(girq, &gpio_eic_irq_chip);
+ }
+
+ if (bank->has_irq) {
+ int ab_parent_irq = platform_get_irq(pdev, 0);
+
+ girq->parent_handler = ep93xx_gpio_ab_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_level_irq;
+ girq->parents[0] = ab_parent_irq;
+ girq->first = bank->irq_base;
+ }
+
+ /* Only bank F has especially funky IRQ handling */
+ if (bank->has_hierarchical_irq) {
+ int gpio_irq;
+ int i;
+
+ /*
+ * FIXME: convert this to use hierarchical IRQ support!
+ * this requires fixing the root irqchip to be hierarchical.
+ */
+ girq->parent_handler = ep93xx_gpio_f_irq_handler;
+ girq->num_parents = 8;
+ girq->parents = devm_kcalloc(dev, girq->num_parents,
+ sizeof(*girq->parents),
+ GFP_KERNEL);
+ if (!girq->parents)
+ return -ENOMEM;
+ /* Pick resources 1..8 for these IRQs */
+ for (i = 0; i < girq->num_parents; i++) {
+ girq->parents[i] = platform_get_irq(pdev, i + 1);
+ gpio_irq = bank->irq_base + i;
+ irq_set_chip_data(gpio_irq, &epg->gc[5]);
+ irq_set_chip_and_handler(gpio_irq,
+ girq->chip,
+ handle_level_irq);
+ irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
+ }
+ girq->default_type = IRQ_TYPE_NONE;
+ girq->handler = handle_level_irq;
+ girq->first = bank->irq_base;
+ }
+
+ return devm_gpiochip_add_data(dev, gc, epg);
+}
+
+static int ep93xx_gpio_probe(struct platform_device *pdev)
+{
+ struct ep93xx_gpio *epg;
+ int i;
+
+ epg = devm_kzalloc(&pdev->dev, sizeof(*epg), GFP_KERNEL);
+ if (!epg)
+ return -ENOMEM;
+
+ epg->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(epg->base))
+ return PTR_ERR(epg->base);
+
+ for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
+ struct ep93xx_gpio_chip *gc = &epg->gc[i];
+ struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
+
+ if (ep93xx_gpio_add_bank(gc, pdev, epg, bank))
+ dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
+ bank->label);
+ }
+
+ 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-14 17:38:10 +0000