1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-imx8.c b/drivers/clk/imx/clk-imx8.c
new file mode 100644
index 000000000000..fb5896a09b79
--- /dev/null
+++ b/drivers/clk/imx/clk-imx8.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Copyright 2017 NXP
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/errno.h>
+#include <soc/imx8/sc/sci.h>
+
+#include "clk-imx8.h"
+
+sc_ipc_t ccm_ipc_handle;
+
+int imx8_clk_mu_init(void)
+{
+	uint32_t mu_id;
+	sc_err_t sciErr;
+
+	printk("MU and Power domains initialized\n");
+
+	sciErr = sc_ipc_getMuID(&mu_id);
+	if (sciErr != SC_ERR_NONE) {
+		pr_info("Cannot obtain MU ID\n");
+		return -EPROBE_DEFER;
+	}
+
+	sciErr = sc_ipc_open(&ccm_ipc_handle, mu_id);
+
+	if (sciErr != SC_ERR_NONE) {
+		pr_info("Cannot open MU channel to SCU\n");
+		return -EPROBE_DEFER;
+	}
+
+	return 0;
+}
+
+bool imx8_clk_is_resource_owned(sc_rsrc_t rsrc)
+{
+	/*
+	 * A-core resources are special. SCFW reports they are not "owned" by
+	 * current partition but linux can still adjust them for cpufreq.
+	 *
+	 * So force this to return false when running as a VM guest and always
+	 * true otherwise.
+	 */
+	if (rsrc == SC_R_A53 || rsrc == SC_R_A72 || rsrc == SC_R_A35) {
+		if (xen_domain() && !xen_initial_domain())
+			return false;
+		return true;
+	}
+
+	if (!ccm_ipc_handle) {
+		pr_warn("%s: no ipc handle!\n", __func__);
+		/* should have handled -EPROBE_DEFER from clk_mu_init earlier. */
+		return false;
+	}
+
+	return sc_rm_is_resource_owned(ccm_ipc_handle, rsrc);
+}