[PATCH 2/6] power: supply: ucs1002: Adjust ucs1002_set_usb_type() to accept string values

[Hans de Goede]

power_supply_sysfs.c accept wrrites of strings to "usb_type" for strings
values matching an entry in POWER_SUPPLY_USB_TYPE_TEXT[]. If such a
string value is written then the int value passed to ucs1002_set_property()
will be an enum power_supply_usb_type value.

Before this change ucs1002_set_usb_type() expected the value to be an index
into ucs1002_usb_types[]. Adjust ucs1002_set_usb_type() to use the enum
value directly so that writing string values works.

The list of supported types in ucs1002_usb_types[] is: PD, SDP, DCP, CDP.
The [POWER_SUPPLY_USB_TYPE_]SDP, DCP and CDP enum labels have a value of
1, 2 and 3. So userspace selecting SDP, DCP or CDP by writing 1, 2 or 3
will keep working. POWER_SUPPLY_USB_TYPE_PD which is mapped to the ucs1002
dedicated mode however has a value of 6. Before this change writing 0 would
select the dedicated mode. To preserve userspace API compatibility also map
POWER_SUPPLY_USB_TYPE_UNKNOWN (which is 0) to the dedicated mode.

Cc: Enric Balletbo Serra <enric.balletbo at collabora.com>
Cc: Andrey Smirnov <andrew.smirnov at gmail.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 drivers/power/supply/ucs1002_power.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/ucs1002_power.c b/drivers/power/supply/ucs1002_power.c
index 7970843a4f48..b67d5b03d93e 100644
--- a/drivers/power/supply/ucs1002_power.c
+++ b/drivers/power/supply/ucs1002_power.c
@@ -308,10 +308,13 @@ static int ucs1002_set_usb_type(struct ucs1002_info *info, int val)
 {
 	unsigned int mode;
 
-	if (val < 0 || val >= ARRAY_SIZE(ucs1002_usb_types))
-		return -EINVAL;
-
-	switch (ucs1002_usb_types[val]) {
+	switch (val) {
+	/*
+	 * POWER_SUPPLY_USB_TYPE_UNKNOWN == 0, map this to dedicated for
+	 * userspace API compatibility with older versions of this driver
+	 * which mapped 0 to dedicated.
+	 */
+	case POWER_SUPPLY_USB_TYPE_UNKNOWN:
 	case POWER_SUPPLY_USB_TYPE_PD:
 		mode = V_SET_ACTIVE_MODE_DEDICATED;
 		break;
-- 
2.46.0