A framework for supporting various General Purpose Input/Output (GPIO)

devices. Such devices provide a set of pins that you can use to connect
for example leds to it.
The pins can be accessed either from userland through the /dev/gpio*
device files or from the kernel drivers. The latter is necessary
for implementing timing-sensitive things like i2c or 1-wire master
controller.

ok deraadt@

6 files changed, 380 insertions, 2 deletions

diff --git a/sys/conf/files b/sys/conf/files
index d4dffc50925..bd6406e43a2 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1,4 +1,4 @@
-#	$OpenBSD: files,v 1.302 2004/05/30 08:11:26 grange Exp $
+#	$OpenBSD: files,v 1.303 2004/06/03 18:07:59 grange Exp $
 #	$NetBSD: files,v 1.87 1996/05/19 17:17:50 jonathan Exp $
 
 #	@(#)files.newconf	7.5 (Berkeley) 5/10/93
@@ -17,6 +17,7 @@ define	midibus { }
 define	midisyn
 define	radiobus {}
 define	i2cbus {}
+define	gpiobus {}
 
 # audio device attributes
 define	mulaw
diff --git a/sys/dev/gpio/files.gpio b/sys/dev/gpio/files.gpio
new file mode 100644
index 00000000000..8f79dfd9170
--- /dev/null
+++ b/sys/dev/gpio/files.gpio
@@ -0,0 +1,7 @@
+# $OpenBSD: files.gpio,v 1.1 2004/06/03 18:08:00 grange Exp $
+
+define	gpio { pin, mask }
+
+device	gpio: gpio
+attach	gpio at gpiobus
+file	dev/gpio/gpio.c				gpio	needs-flag
diff --git a/sys/dev/gpio/gpio.c b/sys/dev/gpio/gpio.c
new file mode 100644
index 00000000000..fa6919745b8
--- /dev/null
+++ b/sys/dev/gpio/gpio.c
@@ -0,0 +1,241 @@
+/*	$OpenBSD: gpio.c,v 1.1 2004/06/03 18:08:00 grange Exp $	*/
+/*
+ * Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * General Purpose I/O framework.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/conf.h>
+#include <sys/device.h>
+#include <sys/ioctl.h>
+#include <sys/gpio.h>
+
+#include <dev/gpio/gpiovar.h>
+
+struct gpio_softc {
+	struct device sc_dev;
+
+	gpio_chipset_tag_t sc_gc;	/* our GPIO controller */
+	gpio_pin_t *sc_pins;		/* pins array */
+	int sc_npins;			/* total number of pins */
+
+	int sc_opened;
+};
+
+int	gpio_match(struct device *, void *, void *);
+void	gpio_attach(struct device *, struct device *, void *);
+int	gpio_search(struct device *, void *, void *);
+int	gpio_print(void *, const char *);
+
+struct cfattach gpio_ca = {
+	sizeof (struct gpio_softc),
+	gpio_match,
+	gpio_attach
+};
+
+struct cfdriver gpio_cd = {
+	NULL, "gpio", DV_DULL
+};
+
+int
+gpio_match(struct device *parent, void *match, void *aux)
+{
+	struct cfdata *cf = match;
+	struct gpiobus_attach_args *gba = aux;
+
+	if (strcmp(gba->gba_name, cf->cf_driver->cd_name) != 0)
+		return (0);
+
+	return (1);
+}
+
+void
+gpio_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct gpio_softc *sc = (struct gpio_softc *)self;
+	struct gpiobus_attach_args *gba = aux;
+
+	sc->sc_gc = gba->gba_gc;
+	sc->sc_pins = gba->gba_pins;
+	sc->sc_npins = gba->gba_npins;
+
+	printf(": %d pins\n", sc->sc_npins);
+
+	/*
+	 * Attach all devices that can be connected to the GPIO pins
+	 * described in the kernel configuration file.
+	 */
+	config_search(gpio_search, self, NULL);
+}
+
+int
+gpio_search(struct device *parent, void *arg, void *aux)
+{
+	struct cfdata *cf = arg;
+	struct gpio_attach_args ga;
+
+	ga.ga_pin = cf->cf_loc[0];
+	ga.ga_mask = cf->cf_loc[1];
+
+	if (cf->cf_attach->ca_match(parent, cf, &ga) > 0)
+		config_attach(parent, cf, &ga, gpio_print);
+
+	return (0);
+}
+
+int
+gpio_print(void *aux, const char *pnp)
+{
+	struct gpio_attach_args *ga = aux;
+	int i;
+
+	printf(" pins");
+	for (i = 0; i < 32; i++)
+		if (ga->ga_mask & (1 << i))
+			printf(" %d", ga->ga_pin + i);
+
+	return (UNCONF);
+}
+
+int
+gpiobus_print(void *aux, const char *pnp)
+{
+	struct gpiobus_attach_args *gba = aux;
+
+	if (pnp != NULL)
+		printf("%s at %s", gba->gba_name, pnp);
+
+	return (UNCONF);
+}
+
+int
+gpioopen(dev_t dev, int flag, int mode, struct proc *p)
+{
+	struct gpio_softc *sc;
+
+	sc = (struct gpio_softc *)device_lookup(&gpio_cd, minor(dev));
+	if (sc == NULL)
+		return (ENXIO);
+
+	if (sc->sc_opened)
+		return (EBUSY);
+	sc->sc_opened = 1;
+
+	return (0);
+}
+
+int
+gpioclose(dev_t dev, int flag, int mode, struct proc *p)
+{
+	struct gpio_softc *sc;
+
+	sc = (struct gpio_softc *)device_lookup(&gpio_cd, minor(dev));
+	sc->sc_opened = 0;
+
+	return (0);
+}
+
+int
+gpioioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
+{
+	struct gpio_softc *sc;
+	gpio_chipset_tag_t gc;
+	struct gpio_info *info;
+	struct gpio_pin_op *op;
+	struct gpio_pin_ctl *ctl;
+	int pin, value, flags;
+
+	sc = (struct gpio_softc *)device_lookup(&gpio_cd, minor(dev));
+	gc = sc->sc_gc;
+
+	switch (cmd) {
+	case GPIOINFO:
+		info = (struct gpio_info *)data;
+
+		info->gpio_npins = sc->sc_npins;
+		break;
+	case GPIOPINREAD:
+		op = (struct gpio_pin_op *)data;
+
+		pin = op->gp_pin;
+		if (pin < 0 || pin >= sc->sc_npins)
+			return (EINVAL);
+
+		/* return read value */
+		op->gp_value = gpiobus_pin_read(gc, pin);
+		break;
+	case GPIOPINWRITE:
+		op = (struct gpio_pin_op *)data;
+
+		pin = op->gp_pin;
+		if (pin < 0 || pin >= sc->sc_npins)
+			return (EINVAL);
+
+		value = op->gp_value;
+		if (value != GPIO_PIN_LOW && value != GPIO_PIN_HIGH)
+			return (EINVAL);
+
+		gpiobus_pin_write(gc, pin, value);
+		/* return old value */
+		op->gp_value = sc->sc_pins[pin].pin_state;
+		/* update current value */
+		sc->sc_pins[pin].pin_state = value;
+		break;
+	case GPIOPINTOGGLE:
+		op = (struct gpio_pin_op *)data;
+
+		pin = op->gp_pin;
+		if (pin < 0 || pin >= sc->sc_npins)
+			return (EINVAL);
+
+		value = (sc->sc_pins[pin].pin_state == GPIO_PIN_LOW ?
+		    GPIO_PIN_HIGH : GPIO_PIN_LOW);
+		gpiobus_pin_write(gc, pin, value);
+		/* return old value */
+		op->gp_value = sc->sc_pins[pin].pin_state;
+		/* update current value */
+		sc->sc_pins[pin].pin_state = value;
+		break;
+	case GPIOPINCTL:
+		ctl = (struct gpio_pin_ctl *)data;
+
+		pin = ctl->gp_pin;
+		if (pin < 0 || pin >= sc->sc_npins)
+			return (EINVAL);
+
+		flags = ctl->gp_flags;
+		/* check that the controller supports all requested flags */
+		if ((flags & sc->sc_pins[pin].pin_caps) != flags)
+			return (ENODEV);
+
+		ctl->gp_caps = sc->sc_pins[pin].pin_caps;
+		/* return old value */
+		ctl->gp_flags = sc->sc_pins[pin].pin_flags;
+		if (flags > 0) {
+			gpiobus_pin_ctl(gc, pin, flags);
+			/* update current value */
+			sc->sc_pins[pin].pin_flags = flags;
+		}
+		break;
+	default:
+		return (ENOTTY);
+	}
+
+	return (0);
+}
diff --git a/sys/dev/gpio/gpiovar.h b/sys/dev/gpio/gpiovar.h
new file mode 100644
index 00000000000..505f557bc65
--- /dev/null
+++ b/sys/dev/gpio/gpiovar.h
@@ -0,0 +1,63 @@
+/*	$OpenBSD: gpiovar.h,v 1.1 2004/06/03 18:08:00 grange Exp $	*/
+/*
+ * Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _DEV_GPIO_GPIOVAR_H_
+#define _DEV_GPIO_GPIOVAR_H_
+
+/* GPIO controller description */
+typedef struct gpio_chipset_tag {
+	void	*gp_cookie;
+
+	int	(*gp_pin_read)(void *, int);
+	void	(*gp_pin_write)(void *, int, int);
+	void	(*gp_pin_ctl)(void *, int, int);
+} *gpio_chipset_tag_t;
+
+/* GPIO pin description */
+typedef struct gpio_pin {
+	int	pin_num;		/* number */
+	int	pin_caps;		/* capabilities */
+	int	pin_flags;		/* current configuration */
+	int	pin_state;		/* current state */
+} gpio_pin_t;
+
+/* Attach GPIO framework to the controller */
+struct gpiobus_attach_args {
+	const char		*gba_name;	/* bus name */
+	gpio_chipset_tag_t	gba_gc;		/* underlying controller */
+	gpio_pin_t		*gba_pins;	/* pins array */
+	int			gba_npins;	/* total number of pins */
+};
+
+int gpiobus_print(void *, const char *);
+
+/* GPIO framework private methods */
+#define gpiobus_pin_read(gc, pin) \
+    ((gc)->gp_pin_read((gc)->gp_cookie, (pin)))
+#define gpiobus_pin_write(gc, pin, value) \
+    ((gc)->gp_pin_write((gc)->gp_cookie, (pin), (value)))
+#define gpiobus_pin_ctl(gc, pin, flags) \
+    ((gc)->gp_pin_ctl((gc)->gp_cookie, (pin), (flags)))
+
+
+/* Attach devices connected to the GPIO pins */
+struct gpio_attach_args {
+	int		ga_pin;
+	u_int32_t	ga_mask;
+};
+
+#endif	/* !_DEV_GPIO_GPIOVAR_H_ */
diff --git a/sys/sys/conf.h b/sys/sys/conf.h
index e85c75f04f1..4707a5c4b26 100644
--- a/sys/sys/conf.h
+++ b/sys/sys/conf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: conf.h,v 1.74 2004/05/30 08:11:27 grange Exp $	*/
+/*	$OpenBSD: conf.h,v 1.75 2004/06/03 18:08:00 grange Exp $	*/
 /*	$NetBSD: conf.h,v 1.33 1996/05/03 20:03:32 christos Exp $	*/
 
 /*-
@@ -473,6 +473,13 @@ void	randomattach(void);
 	(dev_type_stop((*))) enodev, 0, dev_init(c,n,poll), \
 	(dev_type_mmap((*))) enodev, D_KQFILTER, dev_init(c,n,kqfilter) }
 
+/* open, close, ioctl */
+#define cdev_gpio_init(c,n) { \
+	dev_init(c,n,open), dev_init(c,n,close), (dev_type_read((*))) enodev, \
+	(dev_type_write((*))) enodev, dev_init(c,n,ioctl), \
+	(dev_type_stop((*))) enodev, 0, (dev_type_poll((*))) enodev, \
+	(dev_type_mmap((*))) enodev }
+
 /* symbolic sleep message strings */
 extern char devopn[], devio[], devwait[], devin[], devout[];
 extern char devioc[], devcls[];
@@ -631,6 +638,7 @@ cdev_decl(uscanner);
 cdev_decl(urio);
 
 cdev_decl(hotplug);
+cdev_decl(gpio);
 
 #endif
 
diff --git a/sys/sys/gpio.h b/sys/sys/gpio.h
new file mode 100644
index 00000000000..dcc38958ecb
--- /dev/null
+++ b/sys/sys/gpio.h
@@ -0,0 +1,58 @@
+/*	$OpenBSD: gpio.h,v 1.1 2004/06/03 18:08:00 grange Exp $	*/
+/*
+ * Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _SYS_GPIO_H_
+#define _SYS_GPIO_H_
+
+/* GPIO pin states */
+#define GPIO_PIN_LOW		0x00	/* low level (logical 0) */
+#define GPIO_PIN_HIGH		0x01	/* high level (logical 1) */
+
+/* GPIO pin configuration flags */
+#define GPIO_PIN_INPUT		0x0001	/* input direction */
+#define GPIO_PIN_OUTPUT		0x0002	/* output direction */
+#define GPIO_PIN_INOUT		0x0004	/* bi-directional */
+#define GPIO_PIN_OPENDRAIN	0x0008	/* open-drain output */
+#define GPIO_PIN_PUSHPULL	0x0010	/* push-pull output */
+#define GPIO_PIN_TRISTATE	0x0020	/* output disabled */
+#define GPIO_PIN_PULLUP		0x0040	/* internal pull-up enabled */
+
+/* GPIO controller description */
+struct gpio_info {
+	int gpio_npins;		/* total number of pins available */
+};
+
+/* GPIO pin operation (read/write/toggle) */
+struct gpio_pin_op {
+	int gp_pin;		/* pin number */
+	int gp_value;		/* value */
+};
+
+/* GPIO pin control */
+struct gpio_pin_ctl {
+	int gp_pin;		/* pin number */
+	int gp_caps;		/* pin capabilities (read-only) */
+	int gp_flags;		/* pin configuration flags */
+};
+
+#define GPIOINFO		_IOR('G', 0, struct gpio_info)
+#define GPIOPINREAD		_IOWR('G', 1, struct gpio_pin_op)
+#define GPIOPINWRITE		_IOWR('G', 2, struct gpio_pin_op)
+#define GPIOPINTOGGLE		_IOWR('G', 3, struct gpio_pin_op)
+#define GPIOPINCTL		_IOWR('G', 4, struct gpio_pin_ctl)
+
+#endif	/* !_SYS_GPIO_H_ */