sony-laptop: allow complex per-value input/output validation

Replace sony_acpi_value.{min,max} with a callback function that allows
more complex reasoning in accepting input and presenting output.

This allows consistency between the sony-laptop specific 'brightness_default'
and the backlight subsystem 0-based 'brightness'.

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

1 files changed, 62 insertions, 19 deletions

diff --git a/drivers/misc/sony-laptop.c b/drivers/misc/sony-laptop.c
index d7b5330a7bcd..cabbed0015e4 100644
--- a/drivers/misc/sony-laptop.c
+++ b/drivers/misc/sony-laptop.c
@@ -58,13 +58,17 @@ static ssize_t sony_acpi_show(struct device *, struct device_attribute *,
                               char *);
 static ssize_t sony_acpi_store(struct device *, struct device_attribute *,
                                const char *, size_t);
+static int boolean_validate(const int, const int);
+static int brightness_default_validate(const int, const int);
+
+#define SNC_VALIDATE_IN         0
+#define SNC_VALIDATE_OUT        1
 
 struct sony_acpi_value {
         char *name;             /* name of the entry */
         char **acpiget;         /* names of the ACPI get function */
         char **acpiset;         /* names of the ACPI set function */
-        int min;                /* minimum allowed value or -1 */
-        int max;                /* maximum allowed value or -1 */
+        int (*validate)(const int, const int);  /* input/output validation */
         int value;              /* current setting */
         int valid;              /* Has ever been set */
         int debug;              /* active only in debug mode ? */
@@ -74,13 +78,12 @@ struct sony_acpi_value {
 #define HANDLE_NAMES(_name, _values...) \
         static char *snc_##_name[] = { _values, NULL }
 
-#define SONY_ACPI_VALUE(_name, _getters, _setters, _min, _max, _debug) \
+#define SONY_ACPI_VALUE(_name, _getters, _setters, _validate, _debug) \
         { \
                 .name           = __stringify(_name), \
                 .acpiget        = _getters, \
                 .acpiset        = _setters, \
-                .min            = _min, \
-                .max            = _max, \
+                .validate       = _validate, \
                 .debug          = _debug, \
                 .devattr        = __ATTR(_name, 0, sony_acpi_show, sony_acpi_store), \
         }
@@ -114,17 +117,18 @@ HANDLE_NAMES(CMI_set, "SCMI");
 
 static struct sony_acpi_value sony_acpi_values[] = {
         SONY_ACPI_VALUE(brightness_default, snc_brightness_def_get,
-                        snc_brightness_def_set, 1, SONY_MAX_BRIGHTNESS, 0),
-        SONY_ACPI_VALUE(fnkey, snc_fnkey_get, NULL, -1, -1, 0),
-        SONY_ACPI_VALUE(cdpower, snc_cdpower_get, snc_cdpower_set, 0, 1, 0),
-        SONY_ACPI_VALUE(audiopower, snc_audiopower_get, snc_audiopower_set, 0,
-                        1, 0),
-        SONY_ACPI_VALUE(lanpower, snc_lanpower_get, snc_lanpower_set, 0, 1, 1),
+                        snc_brightness_def_set, brightness_default_validate, 0),
+        SONY_ACPI_VALUE(fnkey, snc_fnkey_get, NULL, NULL, 0),
+        SONY_ACPI_VALUE(cdpower, snc_cdpower_get, snc_cdpower_set, boolean_validate, 0),
+        SONY_ACPI_VALUE(audiopower, snc_audiopower_get, snc_audiopower_set,
+                        boolean_validate, 0),
+        SONY_ACPI_VALUE(lanpower, snc_lanpower_get, snc_lanpower_set,
+                        boolean_validate, 1),
         /* unknown methods */
-        SONY_ACPI_VALUE(PID, snc_PID_get, NULL, -1, -1, 1),
-        SONY_ACPI_VALUE(CTR, snc_CTR_get, snc_CTR_set, -1, -1, 1),
-        SONY_ACPI_VALUE(PCR, snc_PCR_get, snc_PCR_set, -1, -1, 1),
-        SONY_ACPI_VALUE(CMI, snc_CMI_get, snc_CMI_set, -1, -1, 1),
+        SONY_ACPI_VALUE(PID, snc_PID_get, NULL, NULL, 1),
+        SONY_ACPI_VALUE(CTR, snc_CTR_get, snc_CTR_set, NULL, 1),
+        SONY_ACPI_VALUE(PCR, snc_PCR_get, snc_PCR_set, NULL, 1),
+        SONY_ACPI_VALUE(CMI, snc_CMI_get, snc_CMI_set, NULL, 1),
         SONY_ACPI_VALUE_NULL
 };
 
@@ -190,6 +194,41 @@ static int acpi_callsetfunc(acpi_handle handle, char *name, int value,
 }
 
 /*
+ * sony_acpi_values input/output validate functions
+ */
+
+/* brightness_default_validate:
+ *
+ * manipulate input output values to keep consistency with the
+ * backlight framework for which brightness values are 0-based.
+ */
+static int brightness_default_validate(const int direction, const int value)
+{
+        switch (direction) {
+                case SNC_VALIDATE_OUT:
+                        return value - 1;
+                case SNC_VALIDATE_IN:
+                        if (value >= 0 && value < SONY_MAX_BRIGHTNESS)
+                                return value + 1;
+        }
+        return -EINVAL;
+}
+
+/* boolean_validate:
+ *
+ * on input validate boolean values 0/1, on output just pass the
+ * received value.
+ */
+static int boolean_validate(const int direction, const int value)
+{
+        if (direction == SNC_VALIDATE_IN) {
+                if (value != 0 && value != 1)
+                        return -EINVAL;
+        }
+        return value;
+}
+
+/*
  * Sysfs show/store common to all sony_acpi_values
  */
 static ssize_t sony_acpi_show(struct device *dev, struct device_attribute *attr,
@@ -205,6 +244,9 @@ static ssize_t sony_acpi_show(struct device *dev, struct device_attribute *attr,
         if (acpi_callgetfunc(sony_acpi_handle, *item->acpiget, &value) < 0)
                 return -EIO;
 
+        if (item->validate)
+                value = item->validate(SNC_VALIDATE_OUT, value);
+
         return snprintf(buffer, PAGE_SIZE, "%d\n", value);
 }
 
@@ -224,10 +266,11 @@ static ssize_t sony_acpi_store(struct device *dev,
 
         value = simple_strtoul(buffer, NULL, 10);
 
-        if (item->min != -1 && value < item->min)
-                return -EINVAL;
-        if (item->max != -1 && value > item->max)
-                return -EINVAL;
+        if (item->validate)
+                value = item->validate(SNC_VALIDATE_IN, value);
+
+        if (value < 0)
+                return value;
 
         if (acpi_callsetfunc(sony_acpi_handle, *item->acpiset, value, NULL) < 0)
                 return -EIO;