i2c-parport-light: Add SMBus alert support

Add support for the SMBus alert mechanism to the i2c-parport-light
driver. The ADM1032 evaluation board at least is properly wired for
this.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Trent Piepho <tpiepho@freescale.com>

2 files changed, 40 insertions, 3 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 4d65546ede44..4cc3807bd31c 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -605,6 +605,7 @@ config I2C_PARPORT
 config I2C_PARPORT_LIGHT
         tristate "Parallel port adapter (light)"
         select I2C_ALGOBIT
+        select I2C_SMBUS
         help
           This supports parallel port I2C adapters such as the ones made by
           Philips or Velleman, Analog Devices evaluation boards, and more.
diff --git a/drivers/i2c/busses/i2c-parport-light.c b/drivers/i2c/busses/i2c-parport-light.c
index 5383f64c5372..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
@@ -32,6 +32,7 @@
 #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"
 
@@ -44,6 +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)
@@ -120,6 +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;
@@ -136,13 +151,31 @@ static int __devinit i2c_parport_probe(struct platform_device *pdev)
 
         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...) */
@@ -209,6 +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;