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-rw-r--r--drivers/gpio/gpio-grgpio.c493
1 files changed, 493 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c
new file mode 100644
index 000000000..c1be299e5
--- /dev/null
+++ b/drivers/gpio/gpio-grgpio.c
@@ -0,0 +1,493 @@
+/*
+ * Driver for Aeroflex Gaisler GRGPIO General Purpose I/O cores.
+ *
+ * 2013 (c) Aeroflex Gaisler AB
+ *
+ * This driver supports the GRGPIO GPIO core available in the GRLIB VHDL
+ * IP core library.
+ *
+ * Full documentation of the GRGPIO core can be found here:
+ * http://www.gaisler.com/products/grlib/grip.pdf
+ *
+ * See "Documentation/devicetree/bindings/gpio/gpio-grgpio.txt" for
+ * information on open firmware properties.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * Contributors: Andreas Larsson <andreas@gaisler.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/gpio/driver.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/bitops.h>
+
+#define GRGPIO_MAX_NGPIO 32
+
+#define GRGPIO_DATA 0x00
+#define GRGPIO_OUTPUT 0x04
+#define GRGPIO_DIR 0x08
+#define GRGPIO_IMASK 0x0c
+#define GRGPIO_IPOL 0x10
+#define GRGPIO_IEDGE 0x14
+#define GRGPIO_BYPASS 0x18
+#define GRGPIO_IMAP_BASE 0x20
+
+/* Structure for an irq of the core - called an underlying irq */
+struct grgpio_uirq {
+ u8 refcnt; /* Reference counter to manage requesting/freeing of uirq */
+ u8 uirq; /* Underlying irq of the gpio driver */
+};
+
+/*
+ * Structure for an irq of a gpio line handed out by this driver. The index is
+ * used to map to the corresponding underlying irq.
+ */
+struct grgpio_lirq {
+ s8 index; /* Index into struct grgpio_priv's uirqs, or -1 */
+ u8 irq; /* irq for the gpio line */
+};
+
+struct grgpio_priv {
+ struct gpio_chip gc;
+ void __iomem *regs;
+ struct device *dev;
+
+ u32 imask; /* irq mask shadow register */
+
+ /*
+ * The grgpio core can have multiple "underlying" irqs. The gpio lines
+ * can be mapped to any one or none of these underlying irqs
+ * independently of each other. This driver sets up an irq domain and
+ * hands out separate irqs to each gpio line
+ */
+ struct irq_domain *domain;
+
+ /*
+ * This array contains information on each underlying irq, each
+ * irq of the grgpio core itself.
+ */
+ struct grgpio_uirq uirqs[GRGPIO_MAX_NGPIO];
+
+ /*
+ * This array contains information for each gpio line on the irqs
+ * obtains from this driver. An index value of -1 for a certain gpio
+ * line indicates that the line has no irq. Otherwise the index connects
+ * the irq to the underlying irq by pointing into the uirqs array.
+ */
+ struct grgpio_lirq lirqs[GRGPIO_MAX_NGPIO];
+};
+
+static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset,
+ int val)
+{
+ struct gpio_chip *gc = &priv->gc;
+
+ if (val)
+ priv->imask |= BIT(offset);
+ else
+ priv->imask &= ~BIT(offset);
+ gc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask);
+}
+
+static int grgpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+ struct grgpio_priv *priv = gpiochip_get_data(gc);
+
+ if (offset >= gc->ngpio)
+ return -ENXIO;
+
+ if (priv->lirqs[offset].index < 0)
+ return -ENXIO;
+
+ return irq_create_mapping(priv->domain, offset);
+}
+
+/* -------------------- IRQ chip functions -------------------- */
+
+static int grgpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
+ unsigned long flags;
+ u32 mask = BIT(d->hwirq);
+ u32 ipol;
+ u32 iedge;
+ u32 pol;
+ u32 edge;
+
+ switch (type) {
+ case IRQ_TYPE_LEVEL_LOW:
+ pol = 0;
+ edge = 0;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ pol = mask;
+ edge = 0;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ pol = 0;
+ edge = mask;
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ pol = mask;
+ edge = mask;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+
+ ipol = priv->gc.read_reg(priv->regs + GRGPIO_IPOL) & ~mask;
+ iedge = priv->gc.read_reg(priv->regs + GRGPIO_IEDGE) & ~mask;
+
+ priv->gc.write_reg(priv->regs + GRGPIO_IPOL, ipol | pol);
+ priv->gc.write_reg(priv->regs + GRGPIO_IEDGE, iedge | edge);
+
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+
+ return 0;
+}
+
+static void grgpio_irq_mask(struct irq_data *d)
+{
+ struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
+ int offset = d->hwirq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+
+ grgpio_set_imask(priv, offset, 0);
+
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+}
+
+static void grgpio_irq_unmask(struct irq_data *d)
+{
+ struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
+ int offset = d->hwirq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+
+ grgpio_set_imask(priv, offset, 1);
+
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+}
+
+static struct irq_chip grgpio_irq_chip = {
+ .name = "grgpio",
+ .irq_mask = grgpio_irq_mask,
+ .irq_unmask = grgpio_irq_unmask,
+ .irq_set_type = grgpio_irq_set_type,
+};
+
+static irqreturn_t grgpio_irq_handler(int irq, void *dev)
+{
+ struct grgpio_priv *priv = dev;
+ int ngpio = priv->gc.ngpio;
+ unsigned long flags;
+ int i;
+ int match = 0;
+
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+
+ /*
+ * For each gpio line, call its interrupt handler if it its underlying
+ * irq matches the current irq that is handled.
+ */
+ for (i = 0; i < ngpio; i++) {
+ struct grgpio_lirq *lirq = &priv->lirqs[i];
+
+ if (priv->imask & BIT(i) && lirq->index >= 0 &&
+ priv->uirqs[lirq->index].uirq == irq) {
+ generic_handle_irq(lirq->irq);
+ match = 1;
+ }
+ }
+
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+
+ if (!match)
+ dev_warn(priv->dev, "No gpio line matched irq %d\n", irq);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * This function will be called as a consequence of the call to
+ * irq_create_mapping in grgpio_to_irq
+ */
+static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ struct grgpio_priv *priv = d->host_data;
+ struct grgpio_lirq *lirq;
+ struct grgpio_uirq *uirq;
+ unsigned long flags;
+ int offset = hwirq;
+ int ret = 0;
+
+ if (!priv)
+ return -EINVAL;
+
+ lirq = &priv->lirqs[offset];
+ if (lirq->index < 0)
+ return -EINVAL;
+
+ dev_dbg(priv->dev, "Mapping irq %d for gpio line %d\n",
+ irq, offset);
+
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+
+ /* Request underlying irq if not already requested */
+ lirq->irq = irq;
+ uirq = &priv->uirqs[lirq->index];
+ if (uirq->refcnt == 0) {
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+ ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
+ dev_name(priv->dev), priv);
+ if (ret) {
+ dev_err(priv->dev,
+ "Could not request underlying irq %d\n",
+ uirq->uirq);
+ return ret;
+ }
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+ }
+ uirq->refcnt++;
+
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+
+ /* Setup irq */
+ irq_set_chip_data(irq, priv);
+ irq_set_chip_and_handler(irq, &grgpio_irq_chip,
+ handle_simple_irq);
+ irq_set_noprobe(irq);
+
+ return ret;
+}
+
+static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
+{
+ struct grgpio_priv *priv = d->host_data;
+ int index;
+ struct grgpio_lirq *lirq;
+ struct grgpio_uirq *uirq;
+ unsigned long flags;
+ int ngpio = priv->gc.ngpio;
+ int i;
+
+ irq_set_chip_and_handler(irq, NULL, NULL);
+ irq_set_chip_data(irq, NULL);
+
+ spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
+
+ /* Free underlying irq if last user unmapped */
+ index = -1;
+ for (i = 0; i < ngpio; i++) {
+ lirq = &priv->lirqs[i];
+ if (lirq->irq == irq) {
+ grgpio_set_imask(priv, i, 0);
+ lirq->irq = 0;
+ index = lirq->index;
+ break;
+ }
+ }
+ WARN_ON(index < 0);
+
+ if (index >= 0) {
+ uirq = &priv->uirqs[lirq->index];
+ uirq->refcnt--;
+ if (uirq->refcnt == 0) {
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+ free_irq(uirq->uirq, priv);
+ return;
+ }
+ }
+
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+}
+
+static const struct irq_domain_ops grgpio_irq_domain_ops = {
+ .map = grgpio_irq_map,
+ .unmap = grgpio_irq_unmap,
+};
+
+/* ------------------------------------------------------------ */
+
+static int grgpio_probe(struct platform_device *ofdev)
+{
+ struct device_node *np = ofdev->dev.of_node;
+ void __iomem *regs;
+ struct gpio_chip *gc;
+ struct grgpio_priv *priv;
+ struct resource *res;
+ int err;
+ u32 prop;
+ s32 *irqmap;
+ int size;
+ int i;
+
+ priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
+ regs = devm_ioremap_resource(&ofdev->dev, res);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ gc = &priv->gc;
+ err = bgpio_init(gc, &ofdev->dev, 4, regs + GRGPIO_DATA,
+ regs + GRGPIO_OUTPUT, NULL, regs + GRGPIO_DIR, NULL,
+ BGPIOF_BIG_ENDIAN_BYTE_ORDER);
+ if (err) {
+ dev_err(&ofdev->dev, "bgpio_init() failed\n");
+ return err;
+ }
+
+ priv->regs = regs;
+ priv->imask = gc->read_reg(regs + GRGPIO_IMASK);
+ priv->dev = &ofdev->dev;
+
+ gc->of_node = np;
+ gc->owner = THIS_MODULE;
+ gc->to_irq = grgpio_to_irq;
+ gc->label = devm_kasprintf(&ofdev->dev, GFP_KERNEL, "%pOF", np);
+ gc->base = -1;
+
+ err = of_property_read_u32(np, "nbits", &prop);
+ if (err || prop <= 0 || prop > GRGPIO_MAX_NGPIO) {
+ gc->ngpio = GRGPIO_MAX_NGPIO;
+ dev_dbg(&ofdev->dev,
+ "No or invalid nbits property: assume %d\n", gc->ngpio);
+ } else {
+ gc->ngpio = prop;
+ }
+
+ /*
+ * The irqmap contains the index values indicating which underlying irq,
+ * if anyone, is connected to that line
+ */
+ irqmap = (s32 *)of_get_property(np, "irqmap", &size);
+ if (irqmap) {
+ if (size < gc->ngpio) {
+ dev_err(&ofdev->dev,
+ "irqmap shorter than ngpio (%d < %d)\n",
+ size, gc->ngpio);
+ return -EINVAL;
+ }
+
+ priv->domain = irq_domain_add_linear(np, gc->ngpio,
+ &grgpio_irq_domain_ops,
+ priv);
+ if (!priv->domain) {
+ 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_data(gc, priv);
+ if (err) {
+ dev_err(&ofdev->dev, "Could not add gpiochip\n");
+ if (priv->domain)
+ irq_domain_remove(priv->domain);
+ 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->gc.bgpio_lock, flags);
+
+ if (priv->domain) {
+ for (i = 0; i < GRGPIO_MAX_NGPIO; i++) {
+ if (priv->uirqs[i].refcnt != 0) {
+ ret = -EBUSY;
+ goto out;
+ }
+ }
+ }
+
+ gpiochip_remove(&priv->gc);
+
+ if (priv->domain)
+ irq_domain_remove(priv->domain);
+
+out:
+ spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
+
+ return ret;
+}
+
+static const 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",
+ .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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 18:13:48 +0000