[PATCH 4/5] platform/x86: msi-ec: Add EC bit operation functions

[Nikita Kravets <teackot@gmail.com>]

The EC of MSI laptops supports several features represented by a single
bit. Add ec_set_bit and ec_check_bit functions to operate on these bits.

Cc: Aakash Singh <mail@singhaakash.dev>
Cc: Jose Angel Pastrana <japp0005@red.ujaen.es>
Signed-off-by: Nikita Kravets <teackot@gmail.com>
---
 drivers/platform/x86/msi-ec.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/platform/x86/msi-ec.c b/drivers/platform/x86/msi-ec.c
index 09472b21e093..ae73dcf01d09 100644
--- a/drivers/platform/x86/msi-ec.c
+++ b/drivers/platform/x86/msi-ec.c
@@ -699,6 +699,34 @@ static int ec_read_seq(u8 addr, u8 *buf, u8 len)
 	return 0;
 }
 
+static int ec_set_bit(u8 addr, u8 bit, bool value)
+{
+	int result;
+	u8 stored;
+
+	result = ec_read(addr, &stored);
+	if (result < 0)
+		return result;
+
+	stored ^= (-(u8) value ^ stored) & (1 << bit);
+
+	return ec_write(addr, stored);
+}
+
+static int ec_check_bit(u8 addr, u8 bit, bool *output)
+{
+	int result;
+	u8 stored;
+
+	result = ec_read(addr, &stored);
+	if (result < 0)
+		return result;
+
+	*output = (stored >> bit) & 1;
+
+	return 0;
+}
+
 static int ec_get_firmware_version(u8 buf[MSI_EC_FW_VERSION_LENGTH + 1])
 {
 	int result;
-- 
2.42.0