patch-2.4.4 linux/arch/cris/drivers/gpio.c

• Lines: 299
• Date: Fri Apr 6 10:42:55 2001
• Orig file: v2.4.3/linux/arch/cris/drivers/gpio.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.3/linux/arch/cris/drivers/gpio.c linux/arch/cris/drivers/gpio.c
@@ -0,0 +1,298 @@
+/* $Id: gpio.c,v 1.4 2001/02/27 13:52:48 bjornw Exp $
+ *
+ * Etrax general port I/O device
+ *
+ * Copyright (c) 1999, 2000, 2001 Axis Communications AB
+ *
+ * Authors:    Bjorn Wesen      (initial version)
+ *             Ola Knutsson     (LED handling)
+ *             Johan Adolfsson  (read/set directions)
+ *
+ * $Log: gpio.c,v $
+ * Revision 1.4  2001/02/27 13:52:48  bjornw
+ * malloc.h -> slab.h
+ *
+ * Revision 1.3  2001/01/24 15:06:48  bjornw
+ * gpio_wq correct type
+ *
+ * Revision 1.2  2001/01/18 16:07:30  bjornw
+ * 2.4 port
+ *
+ * Revision 1.1  2001/01/18 15:55:16  bjornw
+ * Verbatim copy of etraxgpio.c from elinux 2.0 added
+ *
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+
+#include <asm/etraxgpio.h>
+#include <asm/svinto.h>
+#include <asm/io.h>
+#include <asm/system.h>
+
+#define GPIO_MAJOR 120  /* experimental MAJOR number */
+
+#define D(x)
+
+static char gpio_name[] = "etrax gpio";
+
+static wait_queue_head_t *gpio_wq;
+
+static int gpio_ioctl(struct inode *inode, struct file *file,
+		      unsigned int cmd, unsigned long arg);
+static int gpio_open(struct inode *inode, struct file *filp);
+static int gpio_release(struct inode *inode, struct file *filp);
+static unsigned int gpio_poll(struct file *filp, struct poll_table_struct *wait);
+
+/* private data per open() of this driver */
+
+struct gpio_private {
+	struct gpio_private *next;
+	volatile unsigned char *port, *shadow;
+	volatile unsigned char *dir, *dir_shadow;
+	unsigned char changeable_dir;
+	unsigned char changeable_bits;
+	unsigned char highalarm, lowalarm;
+	wait_queue_head_t alarm_wq;
+	int minor;
+};
+
+/* linked list of alarms to check for */
+
+static struct gpio_private *alarmlist = 0;
+
+#define NUM_PORTS 2
+static volatile unsigned char *ports[2] = { R_PORT_PA_DATA, R_PORT_PB_DATA };
+static volatile unsigned char *shads[2] = {
+	&port_pa_data_shadow, &port_pb_data_shadow };
+
+/* What direction bits that are user changeable 1=changeable*/
+#ifndef CONFIG_PA_CHANGEABLE_DIR
+#define CONFIG_PA_CHANGEABLE_DIR 0x00
+#endif
+#ifndef CONFIG_PB_CHANGEABLE_DIR
+#define CONFIG_PB_CHANGEABLE_DIR 0x00
+#endif
+
+#ifndef CONFIG_PA_CHANGEABLE_BITS
+#define CONFIG_PA_CHANGEABLE_BITS 0xFF
+#endif
+#ifndef CONFIG_PB_CHANGEABLE_BITS
+#define CONFIG_PB_CHANGEABLE_BITS 0xFF
+#endif
+
+
+static unsigned char changeable_dir[2] = { CONFIG_PA_CHANGEABLE_DIR,
+                                           CONFIG_PB_CHANGEABLE_DIR };
+static unsigned char changeable_bits[2] = { CONFIG_PA_CHANGEABLE_BITS,
+                                            CONFIG_PB_CHANGEABLE_BITS };
+
+static volatile unsigned char *dir[2] = { R_PORT_PA_DIR, R_PORT_PB_DIR };
+
+static volatile unsigned char *dir_shadow[2] = {
+	&port_pa_dir_shadow, &port_pb_dir_shadow };
+
+#define LEDS 2
+
+static unsigned int 
+gpio_poll(struct file *filp,
+	  struct poll_table_struct *wait)
+{
+	/* TODO poll on alarms! */
+#if 0
+        if(!ANYTHING_WANTED) {
+		D(printk("gpio_select sleeping task\n"));
+	        select_wait(&gpio_wq, table);
+	        return 0;
+	}
+	D(printk("gpio_select ready\n"));
+#endif
+	return 1;
+}
+
+static int
+gpio_open(struct inode *inode, struct file *filp)
+{
+	struct gpio_private *priv;
+	int p = MINOR(inode->i_rdev);
+
+	if(p >= NUM_PORTS && p != LEDS)
+		return -EINVAL;
+
+	priv = (struct gpio_private *)kmalloc(sizeof(struct gpio_private), 
+					      GFP_KERNEL);
+
+	if(!priv)
+		return -ENOMEM;
+
+	priv->minor = p;
+
+	/* initialize the io/alarm struct and link it into our alarmlist */
+
+	priv->next = alarmlist;
+	alarmlist = priv;
+	priv->port = ports[p];
+	priv->shadow = shads[p];
+
+	priv->changeable_dir = changeable_dir[p];
+	priv->changeable_bits = changeable_bits[p];
+	priv->dir = dir[p];
+	priv->dir_shadow = dir_shadow[p];
+
+	priv->highalarm = 0;
+	priv->lowalarm = 0;
+	init_waitqueue_head(&priv->alarm_wq);
+
+	filp->private_data = (void *)priv;
+
+	return 0;
+}
+
+static int
+gpio_release(struct inode *inode, struct file *filp)
+{
+	struct gpio_private *p = alarmlist;
+	struct gpio_private *todel = (struct gpio_private *)filp->private_data;
+
+	/* unlink from alarmlist and free the private structure */
+
+	if(p == todel) {
+		alarmlist = todel->next;
+	} else {
+		while(p->next != todel)
+			p = p->next;
+		p->next = todel->next;
+	}
+
+	kfree(todel);
+
+	return 0;
+}
+
+/* Main device API. ioctl's to read/set/clear bits, as well as to 
+ * set alarms to wait for using a subsequent select().
+ */
+
+static int
+gpio_leds_ioctl(unsigned int cmd, unsigned long arg);
+
+static int
+gpio_ioctl(struct inode *inode, struct file *file,
+	   unsigned int cmd, unsigned long arg)
+{
+	struct gpio_private *priv = (struct gpio_private *)file->private_data;
+
+	if(_IOC_TYPE(cmd) != ETRAXGPIO_IOCTYPE) {
+		return -EINVAL;
+	}
+
+	switch (_IOC_NR(cmd)) {
+		case IO_READBITS:
+			// read the port
+			return *priv->port;
+		case IO_SETBITS:
+			// set changeable bits with a 1 in arg
+			*priv->port = *priv->shadow |= 
+			  ((unsigned char)arg & priv->changeable_bits);
+			break;
+		case IO_CLRBITS:
+			// clear changeable bits with a 1 in arg
+			*priv->port = *priv->shadow &= 
+			  ~((unsigned char)arg & priv->changeable_bits);
+			break;
+		case IO_HIGHALARM:
+			// set alarm when bits with 1 in arg go high
+			priv->highalarm |= (unsigned char)arg;
+			break;
+		case IO_LOWALARM:
+			// set alarm when bits with 1 in arg go low
+			priv->lowalarm |= (unsigned char)arg;
+			break;
+		case IO_CLRALARM:
+			// clear alarm for bits with 1 in arg
+			priv->highalarm &= ~(unsigned char)arg;
+			priv->lowalarm  &= ~(unsigned char)arg;
+			break;
+		case IO_READDIR:
+			/* Read direction 0=input 1=output */
+			return *priv->dir_shadow;
+		case IO_SETINPUT:
+			/* Set direction 0=unchanged 1=input */
+			*priv->dir = *priv->dir_shadow &= 
+			~((unsigned char)arg & priv->changeable_dir);
+			return *priv->dir_shadow;
+		case IO_SETOUTPUT:
+			/* Set direction 0=unchanged 1=output */
+			*priv->dir = *priv->dir_shadow |= 
+			  ((unsigned char)arg & priv->changeable_dir);
+			return *priv->dir_shadow;
+		default:
+			if(priv->minor == LEDS)
+				return gpio_leds_ioctl(cmd, arg);
+			else
+				return -EINVAL;
+	}
+	
+	return 0;
+}
+
+static int
+gpio_leds_ioctl(unsigned int cmd, unsigned long arg)
+{
+	unsigned char green;
+	unsigned char red;
+
+	switch (_IOC_NR(cmd)) {
+		case IO_LEDACTIVE_SET:
+			green = ((unsigned char) arg) & 1;
+			red   = (((unsigned char) arg) >> 1) & 1;
+			LED_ACTIVE_SET_G(green);
+			LED_ACTIVE_SET_R(red);
+			break;
+		default:
+			return -EINVAL;
+	}
+}
+
+struct file_operations gpio_fops = {
+	owner:       THIS_MODULE,
+	poll:        gpio_poll,
+	ioctl:       gpio_ioctl,
+	open:        gpio_open,
+	release:     gpio_release,
+};
+
+/* main driver initialization routine, called from mem.c */
+
+static __init int
+gpio_init(void)
+{
+	int res;
+
+	/* do the formalities */
+
+	res = register_chrdev(GPIO_MAJOR, gpio_name, &gpio_fops);
+	if(res < 0) {
+		printk(KERN_ERR "gpio: couldn't get a major number.\n");
+		return res;
+	}
+	
+	printk("ETRAX 100LX GPIO driver v2.1, (c) 2001 Axis Communications AB\n");
+
+	return res;
+}
+
+/* this makes sure that gpio_init is called during kernel boot */
+
+module_init(gpio_init);