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+/*
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+ * Driver for Aeroflex Gaisler GRGPIO General Purpose I/O cores.
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+ *
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+ * 2013 (c) Aeroflex Gaisler AB
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+ *
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+ * This driver supports the GRGPIO GPIO core available in the GRLIB VHDL
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+ * IP core library.
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+ *
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+ * Full documentation of the GRGPIO core can be found here:
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+ * http://www.gaisler.com/products/grlib/grip.pdf
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+ *
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+ * See "Documentation/devicetree/bindings/gpio/gpio-grgpio.txt" for
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+ * information on open firmware properties.
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+ *
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+ * This program is free software; you can redistribute it and/or modify it
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+ * under the terms of the GNU General Public License as published by the
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+ * Free Software Foundation; either version 2 of the License, or (at your
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+ * option) any later version.
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+ *
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+ * Contributors: Andreas Larsson <andreas@gaisler.com>
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+ */
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+
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+#include <linux/kernel.h>
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+#include <linux/module.h>
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+#include <linux/init.h>
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+#include <linux/spinlock.h>
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+#include <linux/io.h>
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+#include <linux/of.h>
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+#include <linux/of_gpio.h>
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+#include <linux/of_platform.h>
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+#include <linux/gpio.h>
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+#include <linux/slab.h>
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+#include <linux/err.h>
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+#include <linux/basic_mmio_gpio.h>
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+#include <linux/interrupt.h>
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+#include <linux/irq.h>
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+#include <linux/irqdomain.h>
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+
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+#define GRGPIO_MAX_NGPIO 32
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+
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+#define GRGPIO_DATA 0x00
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+#define GRGPIO_OUTPUT 0x04
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+#define GRGPIO_DIR 0x08
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+#define GRGPIO_IMASK 0x0c
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+#define GRGPIO_IPOL 0x10
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+#define GRGPIO_IEDGE 0x14
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+#define GRGPIO_BYPASS 0x18
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+#define GRGPIO_IMAP_BASE 0x20
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+
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+/* Structure for an irq of the core - called an underlying irq */
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+struct grgpio_uirq {
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+ u8 refcnt; /* Reference counter to manage requesting/freeing of uirq */
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+ u8 uirq; /* Underlying irq of the gpio driver */
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+};
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+
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+/*
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+ * Structure for an irq of a gpio line handed out by this driver. The index is
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+ * used to map to the corresponding underlying irq.
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+ */
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+struct grgpio_lirq {
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+ s8 index; /* Index into struct grgpio_priv's uirqs, or -1 */
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+ u8 irq; /* irq for the gpio line */
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+};
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+
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+struct grgpio_priv {
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+ struct bgpio_chip bgc;
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+ void __iomem *regs;
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+ struct device *dev;
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+
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+ u32 imask; /* irq mask shadow register */
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+
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+ /*
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+ * The grgpio core can have multiple "underlying" irqs. The gpio lines
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+ * can be mapped to any one or none of these underlying irqs
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+ * independently of each other. This driver sets up an irq domain and
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+ * hands out separate irqs to each gpio line
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+ */
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+ struct irq_domain *domain;
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+
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+ /*
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+ * This array contains information on each underlying irq, each
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+ * irq of the grgpio core itself.
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+ */
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+ struct grgpio_uirq uirqs[GRGPIO_MAX_NGPIO];
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+
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+ /*
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+ * This array contains information for each gpio line on the irqs
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+ * obtains from this driver. An index value of -1 for a certain gpio
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+ * line indicates that the line has no irq. Otherwise the index connects
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+ * the irq to the underlying irq by pointing into the uirqs array.
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+ */
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+ struct grgpio_lirq lirqs[GRGPIO_MAX_NGPIO];
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+};
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+
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+static inline struct grgpio_priv *grgpio_gc_to_priv(struct gpio_chip *gc)
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+{
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+ struct bgpio_chip *bgc = to_bgpio_chip(gc);
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+
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+ return container_of(bgc, struct grgpio_priv, bgc);
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+}
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+
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+static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset,
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+ int val)
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+{
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+ struct bgpio_chip *bgc = &priv->bgc;
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+ unsigned long mask = bgc->pin2mask(bgc, offset);
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+ unsigned long flags;
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+
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+ spin_lock_irqsave(&bgc->lock, flags);
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+
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+ if (val)
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+ priv->imask |= mask;
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+ else
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+ priv->imask &= ~mask;
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+ bgc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask);
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+
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+ spin_unlock_irqrestore(&bgc->lock, flags);
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+}
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+
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+static int grgpio_to_irq(struct gpio_chip *gc, unsigned offset)
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+{
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+ struct grgpio_priv *priv = grgpio_gc_to_priv(gc);
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+
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+ if (offset > gc->ngpio)
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+ return -ENXIO;
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+
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+ if (priv->lirqs[offset].index < 0)
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+ return -ENXIO;
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+
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+ return irq_create_mapping(priv->domain, offset);
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+}
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+
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+/* -------------------- IRQ chip functions -------------------- */
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+
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+static int grgpio_irq_set_type(struct irq_data *d, unsigned int type)
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+{
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+ struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
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+ unsigned long flags;
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+ u32 mask = BIT(d->hwirq);
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+ u32 ipol;
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+ u32 iedge;
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+ u32 pol;
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+ u32 edge;
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+
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+ switch (type) {
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+ case IRQ_TYPE_LEVEL_LOW:
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+ pol = 0;
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+ edge = 0;
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+ break;
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+ case IRQ_TYPE_LEVEL_HIGH:
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+ pol = mask;
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+ edge = 0;
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+ break;
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+ case IRQ_TYPE_EDGE_FALLING:
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+ pol = 0;
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+ edge = mask;
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+ break;
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+ case IRQ_TYPE_EDGE_RISING:
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+ pol = mask;
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+ edge = mask;
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+ break;
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+ default:
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+ return -EINVAL;
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+ }
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+
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+ spin_lock_irqsave(&priv->bgc.lock, flags);
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+
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+ ipol = priv->bgc.read_reg(priv->regs + GRGPIO_IPOL) & ~mask;
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+ iedge = priv->bgc.read_reg(priv->regs + GRGPIO_IEDGE) & ~mask;
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+
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+ priv->bgc.write_reg(priv->regs + GRGPIO_IPOL, ipol | pol);
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+ priv->bgc.write_reg(priv->regs + GRGPIO_IEDGE, iedge | edge);
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+
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+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
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+
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+ return 0;
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+}
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+
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+static void grgpio_irq_mask(struct irq_data *d)
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+{
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+ struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
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+ int offset = d->hwirq;
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+
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+ grgpio_set_imask(priv, offset, 0);
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+}
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+
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+static void grgpio_irq_unmask(struct irq_data *d)
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+{
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+ struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
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+ int offset = d->hwirq;
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+
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+ grgpio_set_imask(priv, offset, 1);
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+}
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+
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+static struct irq_chip grgpio_irq_chip = {
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+ .name = "grgpio",
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+ .irq_mask = grgpio_irq_mask,
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+ .irq_unmask = grgpio_irq_unmask,
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+ .irq_set_type = grgpio_irq_set_type,
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+};
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+
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+static irqreturn_t grgpio_irq_handler(int irq, void *dev)
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+{
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+ struct grgpio_priv *priv = dev;
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+ int ngpio = priv->bgc.gc.ngpio;
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+ unsigned long flags;
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+ int i;
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+ int match = 0;
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+
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+ spin_lock_irqsave(&priv->bgc.lock, flags);
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+
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+ /*
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+ * For each gpio line, call its interrupt handler if it its underlying
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+ * irq matches the current irq that is handled.
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+ */
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+ for (i = 0; i < ngpio; i++) {
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+ struct grgpio_lirq *lirq = &priv->lirqs[i];
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+
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+ if (priv->imask & BIT(i) && lirq->index >= 0 &&
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+ priv->uirqs[lirq->index].uirq == irq) {
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+ generic_handle_irq(lirq->irq);
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+ match = 1;
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+ }
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+ }
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+
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+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
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+
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+ if (!match)
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+ dev_warn(priv->dev, "No gpio line matched irq %d\n", irq);
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+
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+ return IRQ_HANDLED;
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+}
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+
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+/*
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+ * This function will be called as a consequence of the call to
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+ * irq_create_mapping in grgpio_to_irq
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+ */
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+int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
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+ irq_hw_number_t hwirq)
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+{
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+ struct grgpio_priv *priv = d->host_data;
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+ struct grgpio_lirq *lirq;
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+ struct grgpio_uirq *uirq;
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+ unsigned long flags;
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+ int offset = hwirq;
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+ int ret = 0;
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+
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+ if (!priv)
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+ return -EINVAL;
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+
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+ lirq = &priv->lirqs[offset];
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+ if (lirq->index < 0)
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+ return -EINVAL;
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+
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+ dev_dbg(priv->dev, "Mapping irq %d for gpio line %d\n",
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+ irq, offset);
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+
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+ spin_lock_irqsave(&priv->bgc.lock, flags);
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+
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+ /* Request underlying irq if not already requested */
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+ lirq->irq = irq;
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+ uirq = &priv->uirqs[lirq->index];
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+ if (uirq->refcnt == 0) {
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+ ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
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+ dev_name(priv->dev), priv);
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+ if (ret) {
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+ dev_err(priv->dev,
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+ "Could not request underlying irq %d\n",
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+ uirq->uirq);
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+
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+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
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+
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+ return ret;
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+ }
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+ }
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+ uirq->refcnt++;
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+
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+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
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+
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+ /* Setup irq */
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+ irq_set_chip_data(irq, priv);
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+ irq_set_chip_and_handler(irq, &grgpio_irq_chip,
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+ handle_simple_irq);
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+ irq_clear_status_flags(irq, IRQ_NOREQUEST);
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+#ifdef CONFIG_ARM
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+ set_irq_flags(irq, IRQF_VALID);
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+#else
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+ irq_set_noprobe(irq);
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+#endif
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+
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+ return ret;
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+}
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+
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+void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
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+{
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+ struct grgpio_priv *priv = d->host_data;
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+ int index;
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+ struct grgpio_lirq *lirq;
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+ struct grgpio_uirq *uirq;
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+ unsigned long flags;
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+ int ngpio = priv->bgc.gc.ngpio;
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+ int i;
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+
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+#ifdef CONFIG_ARM
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+ set_irq_flags(irq, 0);
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+#endif
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+ irq_set_chip_and_handler(irq, NULL, NULL);
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+ irq_set_chip_data(irq, NULL);
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+
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+ spin_lock_irqsave(&priv->bgc.lock, flags);
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+
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+ /* Free underlying irq if last user unmapped */
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+ index = -1;
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+ for (i = 0; i < ngpio; i++) {
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+ lirq = &priv->lirqs[i];
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+ if (lirq->irq == irq) {
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+ grgpio_set_imask(priv, i, 0);
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+ lirq->irq = 0;
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+ index = lirq->index;
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+ break;
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+ }
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+ }
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+ WARN_ON(index < 0);
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+
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+ if (index >= 0) {
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+ uirq = &priv->uirqs[lirq->index];
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+ uirq->refcnt--;
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+ if (uirq->refcnt == 0)
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+ free_irq(uirq->uirq, priv);
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+ }
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+
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+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
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+}
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+
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+static struct irq_domain_ops grgpio_irq_domain_ops = {
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+ .map = grgpio_irq_map,
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+ .unmap = grgpio_irq_unmap,
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+};
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+
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+/* ------------------------------------------------------------ */
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+
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+static int grgpio_probe(struct platform_device *ofdev)
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+{
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+ struct device_node *np = ofdev->dev.of_node;
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+ void __iomem *regs;
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+ struct gpio_chip *gc;
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+ struct bgpio_chip *bgc;
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+ struct grgpio_priv *priv;
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+ struct resource *res;
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+ int err;
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+ u32 prop;
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+ s32 *irqmap;
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+ int size;
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+ int i;
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+
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+ priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL);
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+ if (!priv)
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+ return -ENOMEM;
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+
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+ res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
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+ regs = devm_ioremap_resource(&ofdev->dev, res);
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+ if (IS_ERR(regs))
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+ return PTR_ERR(regs);
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+
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+ bgc = &priv->bgc;
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+ err = bgpio_init(bgc, &ofdev->dev, 4, regs + GRGPIO_DATA,
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+ regs + GRGPIO_OUTPUT, NULL, regs + GRGPIO_DIR, NULL,
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+ BGPIOF_BIG_ENDIAN_BYTE_ORDER);
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+ if (err) {
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+ dev_err(&ofdev->dev, "bgpio_init() failed\n");
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+ return err;
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+ }
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+
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+ priv->regs = regs;
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+ priv->imask = bgc->read_reg(regs + GRGPIO_IMASK);
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+ priv->dev = &ofdev->dev;
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+
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+ gc = &bgc->gc;
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+ gc->of_node = np;
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+ gc->owner = THIS_MODULE;
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+ gc->to_irq = grgpio_to_irq;
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+ gc->label = np->full_name;
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+ gc->base = -1;
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+
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+ err = of_property_read_u32(np, "nbits", &prop);
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+ if (err || prop <= 0 || prop > GRGPIO_MAX_NGPIO) {
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+ gc->ngpio = GRGPIO_MAX_NGPIO;
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+ dev_dbg(&ofdev->dev,
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+ "No or invalid nbits property: assume %d\n", gc->ngpio);
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+ } else {
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+ gc->ngpio = prop;
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+ }
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+
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+ /*
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+ * The irqmap contains the index values indicating which underlying irq,
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+ * if anyone, is connected to that line
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+ */
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+ irqmap = (s32 *)of_get_property(np, "irqmap", &size);
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+ if (irqmap) {
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+ if (size < gc->ngpio) {
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+ dev_err(&ofdev->dev,
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+ "irqmap shorter than ngpio (%d < %d)\n",
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+ size, gc->ngpio);
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+ return -EINVAL;
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+ }
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+
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+ priv->domain = irq_domain_add_linear(np, gc->ngpio,
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+ &grgpio_irq_domain_ops,
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+ priv);
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+ if (!priv->domain) {
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|
|
+ dev_err(&ofdev->dev, "Could not add irq domain\n");
|
|
|
+ return -EINVAL;
|
|
|
+ }
|
|
|
+
|
|
|
+ for (i = 0; i < gc->ngpio; i++) {
|
|
|
+ struct grgpio_lirq *lirq;
|
|
|
+ int ret;
|
|
|
+
|
|
|
+ lirq = &priv->lirqs[i];
|
|
|
+ lirq->index = irqmap[i];
|
|
|
+
|
|
|
+ if (lirq->index < 0)
|
|
|
+ continue;
|
|
|
+
|
|
|
+ ret = platform_get_irq(ofdev, lirq->index);
|
|
|
+ if (ret <= 0) {
|
|
|
+ /*
|
|
|
+ * Continue without irq functionality for that
|
|
|
+ * gpio line
|
|
|
+ */
|
|
|
+ dev_err(priv->dev,
|
|
|
+ "Failed to get irq for offset %d\n", i);
|
|
|
+ continue;
|
|
|
+ }
|
|
|
+ priv->uirqs[lirq->index].uirq = ret;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ platform_set_drvdata(ofdev, priv);
|
|
|
+
|
|
|
+ err = gpiochip_add(gc);
|
|
|
+ if (err) {
|
|
|
+ dev_err(&ofdev->dev, "Could not add gpiochip\n");
|
|
|
+ return err;
|
|
|
+ }
|
|
|
+
|
|
|
+ dev_info(&ofdev->dev, "regs=0x%p, base=%d, ngpio=%d, irqs=%s\n",
|
|
|
+ priv->regs, gc->base, gc->ngpio, priv->domain ? "on" : "off");
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+static int grgpio_remove(struct platform_device *ofdev)
|
|
|
+{
|
|
|
+ struct grgpio_priv *priv = platform_get_drvdata(ofdev);
|
|
|
+ unsigned long flags;
|
|
|
+ int i;
|
|
|
+ int ret = 0;
|
|
|
+
|
|
|
+ spin_lock_irqsave(&priv->bgc.lock, flags);
|
|
|
+
|
|
|
+ if (priv->domain) {
|
|
|
+ for (i = 0; i < GRGPIO_MAX_NGPIO; i++) {
|
|
|
+ if (priv->uirqs[i].refcnt != 0) {
|
|
|
+ ret = -EBUSY;
|
|
|
+ goto out;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ ret = gpiochip_remove(&priv->bgc.gc);
|
|
|
+ if (ret)
|
|
|
+ goto out;
|
|
|
+
|
|
|
+ if (priv->domain)
|
|
|
+ irq_domain_remove(priv->domain);
|
|
|
+
|
|
|
+out:
|
|
|
+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
|
|
|
+
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+static struct of_device_id grgpio_match[] = {
|
|
|
+ {.name = "GAISLER_GPIO"},
|
|
|
+ {.name = "01_01a"},
|
|
|
+ {},
|
|
|
+};
|
|
|
+
|
|
|
+MODULE_DEVICE_TABLE(of, grgpio_match);
|
|
|
+
|
|
|
+static struct platform_driver grgpio_driver = {
|
|
|
+ .driver = {
|
|
|
+ .name = "grgpio",
|
|
|
+ .owner = THIS_MODULE,
|
|
|
+ .of_match_table = grgpio_match,
|
|
|
+ },
|
|
|
+ .probe = grgpio_probe,
|
|
|
+ .remove = grgpio_remove,
|
|
|
+};
|
|
|
+module_platform_driver(grgpio_driver);
|
|
|
+
|
|
|
+MODULE_AUTHOR("Aeroflex Gaisler AB.");
|
|
|
+MODULE_DESCRIPTION("Driver for Aeroflex Gaisler GRGPIO");
|
|
|
+MODULE_LICENSE("GPL");
|