ACPI / EC: Add detailed fields debugging support of EC_SC(R).

Developers really don't need to translate EC_SC(R) in mind as long as the
field details are decoded in the debugging message.
Tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/ec.c

@@ -55,6 +55,7 @@
 /* EC status register */
 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
+#define ACPI_EC_FLAG_CMD	0x08	/* Input buffer contains a command */
 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
 
@@ -133,26 +134,33 @@ static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 {
 	u8 x = inb(ec->command_addr);
-	pr_debug("---> status = 0x%2.2x\n", x);
+	pr_debug("EC_SC(R) = 0x%2.2x "
+		 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
+		 x,
+		 !!(x & ACPI_EC_FLAG_SCI),
+		 !!(x & ACPI_EC_FLAG_BURST),
+		 !!(x & ACPI_EC_FLAG_CMD),
+		 !!(x & ACPI_EC_FLAG_IBF),
+		 !!(x & ACPI_EC_FLAG_OBF));
 	return x;
 }
 
 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 {
 	u8 x = inb(ec->data_addr);
-	pr_debug("---> data = 0x%2.2x\n", x);
+	pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
 	return x;
 }
 
 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 {
-	pr_debug("<--- command = 0x%2.2x\n", command);
+	pr_debug("EC_SC(W) = 0x%2.2x\n", command);
 	outb(command, ec->command_addr);
 }
 
 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 {
-	pr_debug("<--- data = 0x%2.2x\n", data);
+	pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
 	outb(data, ec->data_addr);
 }