diff options
Diffstat (limited to 'drivers/gpio/gpio-grgpio.c')
| -rw-r--r-- | drivers/gpio/gpio-grgpio.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c new file mode 100644 index 0000000..466a1c7 --- /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"); |
