ec/google/chromeec: Implement host command to read lid state

On non-LPC platforms (such as those using I2C or SPI for EC comms),
the EC memory map is not directly accessible via memory-mapped I/O.
Instead, these platforms must use the EC_CMD_READ_MEMMAP host command
to retrieve system information.

Implement google_chromeec_get_switches() using this host command for
non-LPC systems. This enables get_lid_switch() to function correctly
on eSPI-based and other non-LPC mainboards, allowing them to support
lid-controlled logic.

BUG=none
TEST=Verify the LID state using get_lid_switch() on Google/Quartz.

Change-Id: Ic7dbe1bcf6b528dfefc168e2f0de0357430dc84d
Signed-off-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91008
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Caveh Jalali <caveh@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>

src/ec/google/chromeec/ec.c

@@ -1992,3 +1992,37 @@ bool google_chromeec_is_critically_low_on_battery(void)
 	return google_chromeec_is_below_critical_threshold() &&
 	       !google_chromeec_is_charger_present();
 }
+
+#if !CONFIG(EC_GOOGLE_CHROMEEC_LPC)
+static int google_chromeec_read_memmap(uint8_t offset, uint8_t size, void *dest)
+{
+	struct ec_params_read_memmap params;
+
+	params.offset = offset;
+	params.size = size;
+
+	struct chromeec_command cmd = {
+		.cmd_code = EC_CMD_READ_MEMMAP,
+		.cmd_version = 0,
+		.cmd_data_in = &params,
+		.cmd_data_out = dest,
+		.cmd_size_in = sizeof(params),
+		.cmd_size_out = size,
+	};
+
+	return google_chromeec_command(&cmd);
+}
+
+/*
+ * Return the byte of EC switch states e.g. lid state
+ */
+uint8_t google_chromeec_get_switches(void)
+{
+	uint8_t flags;
+
+	if (google_chromeec_read_memmap(EC_MEMMAP_SWITCHES, sizeof(flags), &flags))
+		return 0;
+
+	return flags;
+}
+#endif

src/ec/google/chromeec/switches.c

@@ -5,7 +5,6 @@
 #include <elog.h>
 #include <security/vboot/misc.h>
 
-#if CONFIG(EC_GOOGLE_CHROMEEC_LPC)
 /*
  * Retrieves the state of the lid switch.
  *
@@ -32,7 +31,6 @@ int get_lid_switch(void)
 
 	return !!(google_chromeec_get_switches() & EC_SWITCH_LID_OPEN);
 }
-#endif
 
 int get_recovery_mode_switch(void)
 {