sonypi: try to detect if sony-laptop has already taken one of the known ioports

Get the IO resources list in sony-laptop in the same order as listed
in sonypi and make sonypi check if one of those is already busy.
The sonypi check can be disabled by a module parameter in case the user
thinks we are plainly wrong (check_ioport=0).

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/char/sonypi.c b/drivers/char/sonypi.c
index 72cdddb0ee6f..b6998906b214 100644
--- a/drivers/char/sonypi.c
+++ b/drivers/char/sonypi.c
@@ -97,6 +97,11 @@ module_param(useinput, int, 0444);
 MODULE_PARM_DESC(useinput,
                  "set this if you would like sonypi to feed events to the input subsystem");
 
+static int check_ioport = 1;
+module_param(check_ioport, int, 0444);
+MODULE_PARM_DESC(check_ioport,
+                 "set this to 0 if you think the automatic ioport check for sony-laptop is wrong");
+
 #define SONYPI_DEVICE_MODEL_TYPE1       1
 #define SONYPI_DEVICE_MODEL_TYPE2       2
 #define SONYPI_DEVICE_MODEL_TYPE3       3
@@ -1262,6 +1267,28 @@ static int __devinit sonypi_create_input_devices(void)
 static int __devinit sonypi_setup_ioports(struct sonypi_device *dev,
                                 const struct sonypi_ioport_list *ioport_list)
 {
+        /* try to detect if sony-laptop is being used and thus
+         * has already requested one of the known ioports.
+         * As in the deprecated check_region this is racy has we have
+         * multiple ioports available and one of them can be requested
+         * between this check and the subsequent request. Anyway, as an
+         * attempt to be some more user-friendly as we currently are,
+         * this is enough.
+         */
+        const struct sonypi_ioport_list *check = ioport_list;
+        while (check_ioport && check->port1) {
+                if (!request_region(check->port1,
+                                   sonypi_device.region_size,
+                                   "Sony Programable I/O Device Check")) {
+                        printk(KERN_ERR "sonypi: ioport 0x%.4x busy, using sony-laptop? "
+                                        "if not use check_ioport=0\n",
+                                        check->port1);
+                        return -EBUSY;
+                }
+                release_region(check->port1, sonypi_device.region_size);
+                check++;
+        }
+
         while (ioport_list->port1) {
 
                 if (request_region(ioport_list->port1,