[PATCH v9 02/13] arm: mach-k3: am62xx-lpm-common: Add CANUART wakeup check helpers

[Markus Schneider-Pargmann (TI.com)]

Add dedicated helper functions to check CANUART wake registers and magic
word. This helps determining if we are in a wakeup or if CAN IO
isolation has to be removed.

Also add a helper to detect a low power mode exit/resume.

Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp at baylibre.com>
---
 arch/arm/mach-k3/Makefile            |  3 +++
 arch/arm/mach-k3/am62xx-lpm-common.c | 38 ++++++++++++++++++++++++++++++++++++
 arch/arm/mach-k3/am62xx-lpm-common.h | 16 +++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/arch/arm/mach-k3/Makefile b/arch/arm/mach-k3/Makefile
index b2fd5810b67cd8c62af8e0cb4c60020bed2b5624..7a020a8318bae924e6d976fa625b817b37456d84 100644
--- a/arch/arm/mach-k3/Makefile
+++ b/arch/arm/mach-k3/Makefile
@@ -7,6 +7,9 @@ obj-$(CONFIG_ARM64) += arm64/
 obj-$(CONFIG_CPU_V7R) += r5/
 obj-$(CONFIG_OF_LIBFDT) += common_fdt.o
 obj-y += common.o security.o k3-ddr.o
+obj-$(CONFIG_SOC_K3_AM625) += am62xx-lpm-common.o
+obj-$(CONFIG_SOC_K3_AM62A7) += am62xx-lpm-common.o
+obj-$(CONFIG_SOC_K3_AM62P5) += am62xx-lpm-common.o
 obj-$(CONFIG_SOC_K3_AM62A7) += am62ax/
 obj-$(CONFIG_SOC_K3_AM62P5) += am62px/
 obj-$(CONFIG_SOC_K3_AM625) += am62x/
diff --git a/arch/arm/mach-k3/am62xx-lpm-common.c b/arch/arm/mach-k3/am62xx-lpm-common.c
new file mode 100644
index 0000000000000000000000000000000000000000..424d7457c596290ef48acd7f7aec3fd192dd3000
--- /dev/null
+++ b/arch/arm/mach-k3/am62xx-lpm-common.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * am62xx common LPM functions
+ *
+ * Copyright (C) 2025 Texas Instruments Incorporated - https://www.ti.com/
+ * Copyright (C) 2025 BayLibre, SAS
+ */
+
+#include <config.h>
+#include <asm/arch/hardware.h>
+#include <asm/io.h>
+
+#include "am62xx-lpm-common.h"
+
+#define WKUP_CTRL_MMR_CANUART_WAKE_STAT1			0x1830c
+#define WKUP_CTRL_MMR_CANUART_WAKE_STAT1_CANUART_IO_MODE	BIT(0)
+
+#define WKUP_CTRL_MMR_CANUART_WAKE_OFF_MODE_STAT		0x18318
+#define WKUP_CTRL_MMR_CANUART_WAKE_OFF_MODE_STAT_MW		0x555555
+
+static bool wkup_ctrl_canuart_wakeup_active(void)
+{
+	return !!(readl(WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_STAT1) &
+		WKUP_CTRL_MMR_CANUART_WAKE_STAT1_CANUART_IO_MODE);
+}
+
+static bool wkup_ctrl_canuart_magic_word_set(void)
+{
+	return readl(WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_OFF_MODE_STAT) ==
+		WKUP_CTRL_MMR_CANUART_WAKE_OFF_MODE_STAT_MW;
+}
+
+bool wkup_ctrl_is_lpm_exit(void)
+{
+	return IS_ENABLED(CONFIG_K3_IODDR) &&
+		wkup_ctrl_canuart_wakeup_active() &&
+		wkup_ctrl_canuart_magic_word_set();
+}
diff --git a/arch/arm/mach-k3/am62xx-lpm-common.h b/arch/arm/mach-k3/am62xx-lpm-common.h
new file mode 100644
index 0000000000000000000000000000000000000000..36dcd20a9b802bb0eae8dfa56836e7da70107e62
--- /dev/null
+++ b/arch/arm/mach-k3/am62xx-lpm-common.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * am62xx common LPM functions
+ *
+ * Copyright (C) 2025 Texas Instruments Incorporated - https://www.ti.com/
+ * Copyright (C) 2025 BayLibre, SAS
+ */
+
+#ifndef _AM62XX_LPM_COMMON_H_
+#define _AM62XX_LPM_COMMON_H_
+
+#include <asm/io.h>
+
+bool wkup_ctrl_is_lpm_exit(void);
+
+#endif  /* _AM62XX_LPM_COMMON_H_ */

-- 
2.51.0