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path: root/drivers/i2c/busses/i2c-parport.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-parport.c')
-rw-r--r--drivers/i2c/busses/i2c-parport.c154
1 files changed, 97 insertions, 57 deletions
diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
index 71a2502fe06..a27aae2d675 100644
--- a/drivers/i2c/busses/i2c-parport.c
+++ b/drivers/i2c/busses/i2c-parport.c
@@ -1,14 +1,14 @@
/* ------------------------------------------------------------------------ *
* i2c-parport.c I2C bus over parallel port *
* ------------------------------------------------------------------------ *
- Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org>
-
+ Copyright (C) 2003-2011 Jean Delvare <jdelvare@suse.de>
+
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>
-
+ 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
@@ -27,9 +27,14 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/delay.h>
#include <linux/parport.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
+#include <linux/i2c-smbus.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
#include "i2c-parport.h"
/* ----- Device list ------------------------------------------------------ */
@@ -38,10 +43,13 @@ struct i2c_par {
struct pardevice *pdev;
struct i2c_adapter adapter;
struct i2c_algo_bit_data algo_data;
- struct i2c_par *next;
+ struct i2c_smbus_alert_setup alert_data;
+ struct i2c_client *ara;
+ struct list_head node;
};
-static struct i2c_par *adapter_list;
+static LIST_HEAD(adapter_list);
+static DEFINE_MUTEX(adapter_list_lock);
/* ----- Low-level parallel port access ----------------------------------- */
@@ -70,13 +78,13 @@ static unsigned char port_read_control(struct parport *p)
return parport_read_control(p);
}
-static void (*port_write[])(struct parport *, unsigned char) = {
+static void (* const port_write[])(struct parport *, unsigned char) = {
port_write_data,
NULL,
port_write_control,
};
-static unsigned char (*port_read[])(struct parport *) = {
+static unsigned char (* const port_read[])(struct parport *) = {
port_read_data,
port_read_status,
port_read_control,
@@ -132,107 +140,137 @@ static int parport_getsda(void *data)
copied. The attaching code will set getscl to NULL for adapters that
cannot read SCL back, and will also make the data field point to
the parallel port structure. */
-static struct i2c_algo_bit_data parport_algo_data = {
+static const struct i2c_algo_bit_data parport_algo_data = {
.setsda = parport_setsda,
.setscl = parport_setscl,
.getsda = parport_getsda,
.getscl = parport_getscl,
- .udelay = 60,
- .mdelay = 60,
+ .udelay = 10, /* ~50 kbps */
.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_irq(void *data)
+{
+ struct i2c_par *adapter = data;
+ struct i2c_client *ara = adapter->ara;
+
+ if (ara) {
+ dev_dbg(&ara->dev, "SMBus alert received\n");
+ i2c_handle_smbus_alert(ara);
+ } else
+ dev_dbg(&adapter->adapter.dev,
+ "SMBus alert received but no ARA client!\n");
+}
-static void i2c_parport_attach (struct parport *port)
+static void i2c_parport_attach(struct parport *port)
{
struct i2c_par *adapter;
-
- adapter = kmalloc(sizeof(struct i2c_par), GFP_KERNEL);
+
+ adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL);
if (adapter == NULL) {
- printk(KERN_ERR "i2c-parport: Failed to kmalloc\n");
+ printk(KERN_ERR "i2c-parport: Failed to kzalloc\n");
return;
}
- memset(adapter, 0x00, sizeof(struct i2c_par));
pr_debug("i2c-parport: attaching to %s\n", port->name);
+ parport_disable_irq(port);
adapter->pdev = parport_register_device(port, "i2c-parport",
- NULL, NULL, NULL, PARPORT_FLAG_EXCL, NULL);
+ NULL, NULL, i2c_parport_irq, PARPORT_FLAG_EXCL, adapter);
if (!adapter->pdev) {
printk(KERN_ERR "i2c-parport: Unable to register with parport\n");
- goto ERROR0;
+ goto err_free;
}
/* Fill the rest of the structure */
- adapter->adapter = parport_adapter;
+ adapter->adapter.owner = THIS_MODULE;
+ adapter->adapter.class = I2C_CLASS_HWMON;
+ strlcpy(adapter->adapter.name, "Parallel port adapter",
+ sizeof(adapter->adapter.name));
adapter->algo_data = parport_algo_data;
- if (!adapter_parm[type].getscl.val)
+ /* Slow down if we can't sense SCL */
+ if (!adapter_parm[type].getscl.val) {
adapter->algo_data.getscl = NULL;
+ adapter->algo_data.udelay = 50; /* ~10 kbps */
+ }
adapter->algo_data.data = port;
adapter->adapter.algo_data = &adapter->algo_data;
+ adapter->adapter.dev.parent = port->physport->dev;
if (parport_claim_or_block(adapter->pdev) < 0) {
printk(KERN_ERR "i2c-parport: Could not claim parallel port\n");
- goto ERROR1;
+ goto err_unregister;
}
/* 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)
+ if (adapter_parm[type].init.val) {
line_set(port, 1, &adapter_parm[type].init);
-
- parport_release(adapter->pdev);
+ /* Give powered devices some time to settle */
+ msleep(100);
+ }
if (i2c_bit_add_bus(&adapter->adapter) < 0) {
printk(KERN_ERR "i2c-parport: Unable to register with I2C\n");
- goto ERROR1;
+ goto err_unregister;
+ }
+
+ /* Setup SMBus alert if supported */
+ if (adapter_parm[type].smbus_alert) {
+ adapter->alert_data.alert_edge_triggered = 1;
+ adapter->ara = i2c_setup_smbus_alert(&adapter->adapter,
+ &adapter->alert_data);
+ if (adapter->ara)
+ parport_enable_irq(port);
+ else
+ printk(KERN_WARNING "i2c-parport: Failed to register "
+ "ARA client\n");
}
/* Add the new adapter to the list */
- adapter->next = adapter_list;
- adapter_list = adapter;
- return;
+ mutex_lock(&adapter_list_lock);
+ list_add_tail(&adapter->node, &adapter_list);
+ mutex_unlock(&adapter_list_lock);
+ return;
-ERROR1:
+ err_unregister:
+ parport_release(adapter->pdev);
parport_unregister_device(adapter->pdev);
-ERROR0:
+ err_free:
kfree(adapter);
}
-static void i2c_parport_detach (struct parport *port)
+static void i2c_parport_detach(struct parport *port)
{
- struct i2c_par *adapter, *prev;
+ struct i2c_par *adapter, *_n;
/* Walk the list */
- for (prev = NULL, adapter = adapter_list; adapter;
- prev = adapter, adapter = adapter->next) {
+ mutex_lock(&adapter_list_lock);
+ list_for_each_entry_safe(adapter, _n, &adapter_list, node) {
if (adapter->pdev->port == port) {
+ if (adapter->ara) {
+ parport_disable_irq(port);
+ i2c_unregister_device(adapter->ara);
+ }
+ i2c_del_adapter(&adapter->adapter);
+
/* 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_release(adapter->pdev);
parport_unregister_device(adapter->pdev);
- if (prev)
- prev->next = adapter->next;
- else
- adapter_list = adapter->next;
+ list_del(&adapter->node);
kfree(adapter);
- return;
}
}
+ mutex_unlock(&adapter_list_lock);
}
-static struct parport_driver i2c_driver = {
+static struct parport_driver i2c_parport_driver = {
.name = "i2c-parport",
.attach = i2c_parport_attach,
.detach = i2c_parport_detach,
@@ -242,23 +280,25 @@ static struct parport_driver i2c_driver = {
static int __init i2c_parport_init(void)
{
- int type_count;
+ if (type < 0) {
+ printk(KERN_WARNING "i2c-parport: adapter type unspecified\n");
+ return -ENODEV;
+ }
- type_count = sizeof(adapter_parm)/sizeof(struct adapter_parm);
- if (type < 0 || type >= type_count) {
+ if (type >= ARRAY_SIZE(adapter_parm)) {
printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type);
- type = 0;
+ return -ENODEV;
}
-
- return parport_register_driver(&i2c_driver);
+
+ return parport_register_driver(&i2c_parport_driver);
}
static void __exit i2c_parport_exit(void)
{
- parport_unregister_driver(&i2c_driver);
+ parport_unregister_driver(&i2c_parport_driver);
}
-MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
+MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("I2C bus over parallel port");
MODULE_LICENSE("GPL");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-13 16:15:59 +0000