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>

diff --git a/Documentation/i2c/busses/i2c-parport-light b/Documentation/i2c/busses/i2c-parport-light
index 287436478520a00edbbabafb2e5812800b9ed483..bdc9cbb2e0f2df74086c092d52036c59e7267dbe 100644 (file)
--- a/Documentation/i2c/busses/i2c-parport-light
+++ b/Documentation/i2c/busses/i2c-parport-light
@@ -9,3 +9,14 @@ parport handling is not an option. The drawback is a reduced portability
 and the impossibility to daisy-chain other parallel port devices.                 
   
 Please see i2c-parport for documentation.
+
+Module parameters:
+
+* type: type of adapter (see i2c-parport or modinfo)
+
+* base: base I/O address
+  Default is 0x378 which is fairly common for parallel ports, at least on PC.
+
+* irq: optional IRQ
+  This must be passed if you want SMBus alert support, assuming your adapter
+  actually supports this.

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 4d65546ede44368d66da376900205a77b1ba6238..4cc3807bd31caa1a768bbae348c8029ab598ac5b 100644 (file)
--- 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 5383f64c53729aa3e44458a184a5746a779958ea..5f41ec0f72d23c2d090869005597a93132991e55 100644 (file)
--- 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;