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path: root/drivers/i2c/busses/i2c-parport-light.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-parport-light.c')
-rw-r--r--drivers/i2c/busses/i2c-parport-light.c48
1 files changed, 44 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-parport-light.c b/drivers/i2c/busses/i2c-parport-light.c
index 322c5691e38e..5f41ec0f72d2 100644
--- a/drivers/i2c/busses/i2c-parport-light.c
+++ b/drivers/i2c/busses/i2c-parport-light.c
@@ -1,7 +1,7 @@
/* ------------------------------------------------------------------------ *
* i2c-parport-light.c I2C bus over parallel port *
* ------------------------------------------------------------------------ *
- Copyright (C) 2003-2007 Jean Delvare <khali@linux-fr.org>
+ Copyright (C) 2003-2010 Jean Delvare <khali@linux-fr.org>
Based on older i2c-velleman.c driver
Copyright (C) 1995-2000 Simon G. Vogl
@@ -27,10 +27,12 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
+#include <linux/i2c-smbus.h>
#include <asm/io.h>
#include "i2c-parport.h"
@@ -43,6 +45,10 @@ static u16 base;
module_param(base, ushort, 0);
MODULE_PARM_DESC(base, "Base I/O address");
+static int irq;
+module_param(irq, int, 0);
+MODULE_PARM_DESC(irq, "IRQ (optional)");
+
/* ----- Low-level parallel port access ----------------------------------- */
static inline void port_write(unsigned char p, unsigned char d)
@@ -119,6 +125,16 @@ static struct i2c_adapter parport_adapter = {
.name = "Parallel port adapter (light)",
};
+/* SMBus alert support */
+static struct i2c_smbus_alert_setup alert_data = {
+ .alert_edge_triggered = 1,
+};
+static struct i2c_client *ara;
+static struct lineop parport_ctrl_irq = {
+ .val = (1 << 4),
+ .port = CTRL,
+};
+
static int __devinit i2c_parport_probe(struct platform_device *pdev)
{
int err;
@@ -127,18 +143,39 @@ static int __devinit i2c_parport_probe(struct platform_device *pdev)
parport_setsda(NULL, 1);
parport_setscl(NULL, 1);
/* Other init if needed (power on...) */
- if (adapter_parm[type].init.val)
+ if (adapter_parm[type].init.val) {
line_set(1, &adapter_parm[type].init);
+ /* Give powered devices some time to settle */
+ msleep(100);
+ }
parport_adapter.dev.parent = &pdev->dev;
err = i2c_bit_add_bus(&parport_adapter);
- if (err)
+ if (err) {
dev_err(&pdev->dev, "Unable to register with I2C\n");
- return err;
+ return err;
+ }
+
+ /* Setup SMBus alert if supported */
+ if (adapter_parm[type].smbus_alert && irq) {
+ alert_data.irq = irq;
+ ara = i2c_setup_smbus_alert(&parport_adapter, &alert_data);
+ if (ara)
+ line_set(1, &parport_ctrl_irq);
+ else
+ dev_warn(&pdev->dev, "Failed to register ARA client\n");
+ }
+
+ return 0;
}
static int __devexit i2c_parport_remove(struct platform_device *pdev)
{
+ if (ara) {
+ line_set(0, &parport_ctrl_irq);
+ i2c_unregister_device(ara);
+ ara = NULL;
+ }
i2c_del_adapter(&parport_adapter);
/* Un-init if needed (power off...) */
@@ -205,6 +242,9 @@ static int __init i2c_parport_init(void)
if (!request_region(base, 3, DRVNAME))
return -EBUSY;
+ if (irq != 0)
+ pr_info(DRVNAME ": using irq %d\n", irq);
+
if (!adapter_parm[type].getscl.val)
parport_algo_data.getscl = NULL;