1 files changed, 267 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
new file mode 100644
index 000000000000..e9560bab51c4
--- /dev/null
+++ b/drivers/i2c/busses/i2c-parport.c
@@ -0,0 +1,267 @@
+/* ------------------------------------------------------------------------ *
+ * i2c-parport.c I2C bus over parallel port                                 *
+ * ------------------------------------------------------------------------ *
+   Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org>
+   
+   Based on older i2c-philips-par.c driver
+   Copyright (C) 1995-2000 Simon G. Vogl
+   With some changes from:
+   Frodo Looijaard <frodol@dds.nl>
+   Kyösti Mälkki <kmalkki@cc.hut.fi>
+   
+   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/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/parport.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include "i2c-parport.h"
+
+/* ----- Device list ------------------------------------------------------ */
+
+struct i2c_par {
+        struct pardevice *pdev;
+        struct i2c_adapter adapter;
+        struct i2c_algo_bit_data algo_data;
+        struct i2c_par *next;
+};
+
+static struct i2c_par *adapter_list;
+
+/* ----- Low-level parallel port access ----------------------------------- */
+
+static void port_write_data(struct parport *p, unsigned char d)
+{
+        parport_write_data(p, d);
+}
+
+static void port_write_control(struct parport *p, unsigned char d)
+{
+        parport_write_control(p, d);
+}
+
+static unsigned char port_read_data(struct parport *p)
+{
+        return parport_read_data(p);
+}
+
+static unsigned char port_read_status(struct parport *p)
+{
+        return parport_read_status(p);
+}
+
+static unsigned char port_read_control(struct parport *p)
+{
+        return parport_read_control(p);
+}
+
+static void (*port_write[])(struct parport *, unsigned char) = {
+        port_write_data,
+        NULL,
+        port_write_control,
+};
+
+static unsigned char (*port_read[])(struct parport *) = {
+        port_read_data,
+        port_read_status,
+        port_read_control,
+};
+
+/* ----- Unified line operation functions --------------------------------- */
+
+static inline void line_set(struct parport *data, int state,
+        const struct lineop *op)
+{
+        u8 oldval = port_read[op->port](data);
+
+        /* Touch only the bit(s) needed */
+        if ((op->inverted && !state) || (!op->inverted && state))
+                port_write[op->port](data, oldval | op->val);
+        else
+                port_write[op->port](data, oldval & ~op->val);
+}
+
+static inline int line_get(struct parport *data,
+        const struct lineop *op)
+{
+        u8 oldval = port_read[op->port](data);
+
+        return ((op->inverted && (oldval & op->val) != op->val)
+            || (!op->inverted && (oldval & op->val) == op->val));
+}
+
+/* ----- I2C algorithm call-back functions and structures ----------------- */
+
+static void parport_setscl(void *data, int state)
+{
+        line_set((struct parport *) data, state, &adapter_parm[type].setscl);
+}
+
+static void parport_setsda(void *data, int state)
+{
+        line_set((struct parport *) data, state, &adapter_parm[type].setsda);
+}
+
+static int parport_getscl(void *data)
+{
+        return line_get((struct parport *) data, &adapter_parm[type].getscl);
+}
+
+static int parport_getsda(void *data)
+{
+        return line_get((struct parport *) data, &adapter_parm[type].getsda);
+}
+
+/* Encapsulate the functions above in the correct structure.
+   Note that this is only a template, from which the real structures are
+   copied. The attaching code will set getscl to NULL for adapters that
+   cannot read SCL back, and will also make the the data field point to
+   the parallel port structure. */
+static struct i2c_algo_bit_data parport_algo_data = {
+        .setsda         = parport_setsda,
+        .setscl         = parport_setscl,
+        .getsda         = parport_getsda,
+        .getscl         = parport_getscl,
+        .udelay         = 60,
+        .mdelay         = 60,
+        .timeout        = HZ,
+}; 
+
+/* ----- I2c and parallel port call-back functions and structures --------- */
+
+static struct i2c_adapter parport_adapter = {
+        .owner          = THIS_MODULE,
+        .class          = I2C_CLASS_HWMON,
+        .id             = I2C_HW_B_LP,
+        .name           = "Parallel port adapter",
+};
+
+static void i2c_parport_attach (struct parport *port)
+{
+        struct i2c_par *adapter;
+        
+        adapter = kmalloc(sizeof(struct i2c_par), GFP_KERNEL);
+        if (adapter == NULL) {
+                printk(KERN_ERR "i2c-parport: Failed to kmalloc\n");
+                return;
+        }
+        memset(adapter, 0x00, sizeof(struct i2c_par));
+
+        pr_debug("i2c-parport: attaching to %s\n", port->name);
+        adapter->pdev = parport_register_device(port, "i2c-parport",
+                NULL, NULL, NULL, PARPORT_FLAG_EXCL, NULL);
+        if (!adapter->pdev) {
+                printk(KERN_ERR "i2c-parport: Unable to register with parport\n");
+                goto ERROR0;
+        }
+
+        /* Fill the rest of the structure */
+        adapter->adapter = parport_adapter;
+        adapter->algo_data = parport_algo_data;
+        if (!adapter_parm[type].getscl.val)
+                adapter->algo_data.getscl = NULL;
+        adapter->algo_data.data = port;
+        adapter->adapter.algo_data = &adapter->algo_data;
+
+        if (parport_claim_or_block(adapter->pdev) < 0) {
+                printk(KERN_ERR "i2c-parport: Could not claim parallel port\n");
+                goto ERROR1;
+        }
+
+        /* Reset hardware to a sane state (SCL and SDA high) */
+        parport_setsda(port, 1);
+        parport_setscl(port, 1);
+        /* Other init if needed (power on...) */
+        if (adapter_parm[type].init.val)
+                line_set(port, 1, &adapter_parm[type].init);
+
+        parport_release(adapter->pdev);
+
+        if (i2c_bit_add_bus(&adapter->adapter) < 0) {
+                printk(KERN_ERR "i2c-parport: Unable to register with I2C\n");
+                goto ERROR1;
+        }
+
+        /* Add the new adapter to the list */
+        adapter->next = adapter_list;
+        adapter_list = adapter;
+        return;
+
+ERROR1:
+        parport_unregister_device(adapter->pdev);
+ERROR0:
+        kfree(adapter);
+}
+
+static void i2c_parport_detach (struct parport *port)
+{
+        struct i2c_par *adapter, *prev;
+
+        /* Walk the list */
+        for (prev = NULL, adapter = adapter_list; adapter;
+             prev = adapter, adapter = adapter->next) {
+                if (adapter->pdev->port == port) {
+                        /* Un-init if needed (power off...) */
+                        if (adapter_parm[type].init.val)
+                                line_set(port, 0, &adapter_parm[type].init);
+                                
+                        i2c_bit_del_bus(&adapter->adapter);
+                        parport_unregister_device(adapter->pdev);
+                        if (prev)
+                                prev->next = adapter->next;
+                        else
+                                adapter_list = adapter->next;
+                        kfree(adapter);
+                        return;
+                }
+        }
+}
+
+static struct parport_driver i2c_driver = {
+        .name   = "i2c-parport",
+        .attach = i2c_parport_attach,
+        .detach = i2c_parport_detach,
+};
+
+/* ----- Module loading, unloading and information ------------------------ */
+
+static int __init i2c_parport_init(void)
+{
+        int type_count;
+
+        type_count = sizeof(adapter_parm)/sizeof(struct adapter_parm);
+        if (type < 0 || type >= type_count) {
+                printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type);
+                type = 0;
+        }
+        
+        return parport_register_driver(&i2c_driver);
+}
+
+static void __exit i2c_parport_exit(void)
+{
+        parport_unregister_driver(&i2c_driver);
+}
+
+MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
+MODULE_DESCRIPTION("I2C bus over parallel port");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_parport_init);
+module_exit(i2c_parport_exit);