patch-2.4.21 linux-2.4.21/drivers/i2c/scx200_i2c.c

• Lines: 157
• Date: 2003-06-13 07:51:33.000000000 -0700
• Orig file: linux-2.4.20/drivers/i2c/scx200_i2c.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/drivers/i2c/scx200_i2c.c linux-2.4.21/drivers/i2c/scx200_i2c.c
@@ -0,0 +1,156 @@
+/* linux/drivers/i2c/scx200_i2c.c 
+
+   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
+
+   National Semiconductor SCx200 I2C bus on GPIO pins
+
+   Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl
+
+   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.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <asm/io.h>
+
+#include <linux/scx200_gpio.h>
+
+#define NAME "scx200_i2c"
+
+MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
+MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver");
+MODULE_LICENSE("GPL");
+
+MODULE_PARM(scl, "i");
+MODULE_PARM_DESC(scl, "GPIO line for SCL");
+MODULE_PARM(sda, "i");
+MODULE_PARM_DESC(sda, "GPIO line for SDA");
+
+static int scl = CONFIG_SCx200_I2C_SCL;
+static int sda = CONFIG_SCx200_I2C_SDA;
+
+static void scx200_i2c_setscl(void *data, int state)
+{
+	scx200_gpio_set(scl, state);
+}
+
+static void scx200_i2c_setsda(void *data, int state)
+{
+	scx200_gpio_set(sda, state);
+} 
+
+static int scx200_i2c_getscl(void *data)
+{
+	return scx200_gpio_get(scl);
+}
+
+static int scx200_i2c_getsda(void *data)
+{
+	return scx200_gpio_get(sda);
+}
+
+static int scx200_i2c_reg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static int scx200_i2c_unreg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static void scx200_i2c_inc_use(struct i2c_adapter *adap)
+{
+	MOD_INC_USE_COUNT;
+}
+
+static void scx200_i2c_dec_use(struct i2c_adapter *adap)
+{
+	MOD_DEC_USE_COUNT;
+}
+
+/* ------------------------------------------------------------------------
+ * Encapsulate the above functions in the correct operations structure.
+ * This is only done when more than one hardware adapter is supported.
+ */
+
+static struct i2c_algo_bit_data scx200_i2c_data = {
+	NULL,
+	scx200_i2c_setsda,
+	scx200_i2c_setscl,
+	scx200_i2c_getsda,
+	scx200_i2c_getscl,
+	10, 10, 100,		/* waits, timeout */
+};
+
+static struct i2c_adapter scx200_i2c_ops = {
+	.name              = "NatSemi SCx200 I2C",
+	.id		   = I2C_HW_B_VELLE,
+	.algo_data	   = &scx200_i2c_data,
+	.inc_use	   = scx200_i2c_inc_use,
+	.dec_use	   = scx200_i2c_dec_use,
+	.client_register   = scx200_i2c_reg,
+	.client_unregister = scx200_i2c_unreg,
+};
+
+int scx200_i2c_init(void)
+{
+	printk(KERN_DEBUG NAME ": NatSemi SCx200 I2C Driver\n");
+
+	if (!scx200_gpio_present()) {
+		printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
+		return -ENODEV;
+	}
+
+	printk(KERN_DEBUG NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n", 
+	       scl, sda);
+
+	if (scl == -1 || sda == -1 || scl == sda) {
+		printk(KERN_ERR NAME ": scl and sda must be specified\n");
+		return -EINVAL;
+	}
+
+	/* Configure GPIOs as open collector outputs */
+	scx200_gpio_configure(scl, ~2, 5);
+	scx200_gpio_configure(sda, ~2, 5);
+
+	if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) {
+		printk(KERN_ERR NAME ": adapter %s registration failed\n", 
+		       scx200_i2c_ops.name);
+		return -ENODEV;
+	}
+	
+	return 0;
+}
+
+void scx200_i2c_cleanup(void)
+{
+	i2c_bit_del_bus(&scx200_i2c_ops);
+}
+
+module_init(scx200_i2c_init);
+module_exit(scx200_i2c_cleanup);
+
+/*
+    Local variables:
+        compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"
+        c-basic-offset: 8
+    End:
+*/