x86: sandbox: Add a PMC emulator and test

Add a simple PMC for sandbox to permit tests to run.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/cmd/pmc.c b/cmd/pmc.c
new file mode 100644
index 0000000..cafeba9
--- /dev/null
+++ b/cmd/pmc.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel PMC command
+ *
+ * Copyright 2019 Google LLC
+ */
+
+#include <common.h>
+#include <command.h>
+#include <dm.h>
+#include <power/acpi_pmc.h>
+
+static int get_pmc_dev(struct udevice **devp)
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = uclass_first_device_err(UCLASS_ACPI_PMC, &dev);
+	if (ret) {
+		printf("Could not find device (err=%d)\n", ret);
+		return ret;
+	}
+	ret = pmc_init(dev);
+	if (ret) {
+		printf("Could not init device (err=%d)\n", ret);
+		return ret;
+	}
+	*devp = dev;
+
+	return 0;
+}
+
+static int do_pmc_init(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = get_pmc_dev(&dev);
+	if (ret)
+		return CMD_RET_FAILURE;
+
+	return 0;
+}
+
+static int do_pmc_info(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = get_pmc_dev(&dev);
+	if (ret)
+		return CMD_RET_FAILURE;
+	pmc_dump_info(dev);
+
+	return 0;
+}
+
+static cmd_tbl_t cmd_pmc_sub[] = {
+	U_BOOT_CMD_MKENT(init, 0, 1, do_pmc_init, "", ""),
+	U_BOOT_CMD_MKENT(info, 0, 1, do_pmc_info, "", ""),
+};
+
+static int do_pmc(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	const cmd_tbl_t *cp;
+
+	if (argc < 2) /* no subcommand */
+		return cmd_usage(cmdtp);
+
+	cp = find_cmd_tbl(argv[1], &cmd_pmc_sub[0], ARRAY_SIZE(cmd_pmc_sub));
+	if (!cp)
+		return CMD_RET_USAGE;
+
+	return cp->cmd(cmdtp, flag, argc, argv);
+}
+
+U_BOOT_CMD(
+	pmc, 2, 1, do_pmc, "Power-management controller info",
+	"info - read state and show info about the PMC\n"
+	"pmc init - read state from the PMC\n"
+	);