gpio: grgpio: Add device driver for GRGPIO cores

This driver supports GRGPIO gpio cores available in the GRLIB VHDL IP
core library from Aeroflex Gaisler.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 159 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 704d01d67522..345c6672709c 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -309,6 +309,15 @@ config GPIO_LYNXPOINT
           driver for GPIO functionality on Intel Lynxpoint PCH chipset
           Requires ACPI device enumeration code to set up a platform device.
 
+config GPIO_GRGPIO
+        tristate "Aeroflex Gaisler GRGPIO support"
+        depends on OF
+        select GPIO_GENERIC
+        select IRQ_DOMAIN
+        help
+          Select this to support Aeroflex Gaisler GRGPIO cores from the GRLIB
+          VHDL IP core library.
+
 comment "I2C GPIO expanders:"
 
 config GPIO_ARIZONA
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 22e07bc9fcb5..3e6be5134122 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_ARCH_DAVINCI)	+= gpio-davinci.o
 obj-$(CONFIG_GPIO_EM)           += gpio-em.o
 obj-$(CONFIG_GPIO_EP93XX)       += gpio-ep93xx.o
 obj-$(CONFIG_GPIO_GE_FPGA)      += gpio-ge.o
+obj-$(CONFIG_GPIO_GRGPIO)       += gpio-grgpio.o
 obj-$(CONFIG_GPIO_ICH)          += gpio-ich.o
 obj-$(CONFIG_GPIO_IT8761E)      += gpio-it8761e.o
 obj-$(CONFIG_GPIO_JANZ_TTL)     += gpio-janz-ttl.o
diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c
new file mode 100644
index 000000000000..466a1c757fae
--- /dev/null
+++ b/drivers/gpio/gpio-grgpio.c
@@ -0,0 +1,149 @@
+/*
+ * 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_gpio.h>
+#include <linux/of_platform.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/basic_mmio_gpio.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
+
+struct grgpio_priv {
+        struct bgpio_chip bgc;
+        void __iomem *regs;
+        struct device *dev;
+};
+
+static inline struct grgpio_priv *grgpio_gc_to_priv(struct gpio_chip *gc)
+{
+        struct bgpio_chip *bgc = to_bgpio_chip(gc);
+
+        return container_of(bgc, struct grgpio_priv, bgc);
+}
+
+static int grgpio_probe(struct platform_device *ofdev)
+{
+        struct device_node *np = ofdev->dev.of_node;
+        void  __iomem *regs;
+        struct gpio_chip *gc;
+        struct bgpio_chip *bgc;
+        struct grgpio_priv *priv;
+        struct resource *res;
+        int err;
+        u32 prop;
+
+        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);
+
+        bgc = &priv->bgc;
+        err = bgpio_init(bgc, &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->dev = &ofdev->dev;
+
+        gc = &bgc->gc;
+        gc->of_node = np;
+        gc->owner = THIS_MODULE;
+        gc->label = np->full_name;
+        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;
+        }
+
+        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\n",
+                 priv->regs, gc->base, gc->ngpio);
+
+        return 0;
+}
+
+static int grgpio_remove(struct platform_device *ofdev)
+{
+        struct grgpio_priv *priv = platform_get_drvdata(ofdev);
+
+        return gpiochip_remove(&priv->bgc.gc);
+}
+
+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");