arm: mach-k3: Remove CANUART IO isolation

After leaving the Partial-IO mode or other deep sleep states, the IO
isolation needs to be removed. This routine is shared by at least am62,
am62a and am62p.

The original function for testing was developed by
Akashdeep Kaur <a-kaur@ti.com>

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>

6 files changed, 92 insertions, 0 deletions

diff --git a/arch/arm/mach-k3/am625_init.c b/arch/arm/mach-k3/am625_init.c
index d5d741cb93..ccbfad29d7 100644
--- a/arch/arm/mach-k3/am625_init.c
+++ b/arch/arm/mach-k3/am625_init.c
@@ -135,6 +135,8 @@ void board_init_f(ulong dummy)
 	/* Init DM early */
 	spl_early_init();
 
+	wkup_ctrl_remove_can_io_isolation_if_set();
+
 	/*
 	 * Process pinctrl for the serial0 and serial3, aka WKUP_UART0 and
 	 * MAIN_UART1 modules and continue regardless of the result of pinctrl.
diff --git a/arch/arm/mach-k3/am62a7_init.c b/arch/arm/mach-k3/am62a7_init.c
index 0b044bf037..5a96683c53 100644
--- a/arch/arm/mach-k3/am62a7_init.c
+++ b/arch/arm/mach-k3/am62a7_init.c
@@ -103,6 +103,8 @@ void board_init_f(ulong dummy)
 	/* Init DM early */
 	spl_early_init();
 
+	wkup_ctrl_remove_can_io_isolation_if_set();
+
 	/*
 	 * Process pinctrl for the serial0 and serial3, aka WKUP_UART0 and
 	 * MAIN_UART1 modules and continue regardless of the result of pinctrl.
diff --git a/arch/arm/mach-k3/am62p5_init.c b/arch/arm/mach-k3/am62p5_init.c
index 55535a3ff9..ac1b01bd84 100644
--- a/arch/arm/mach-k3/am62p5_init.c
+++ b/arch/arm/mach-k3/am62p5_init.c
@@ -88,6 +88,8 @@ void board_init_f(ulong dummy)
 	if (ret)
 		panic("spl_early_init() failed: %d\n", ret);
 
+	wkup_ctrl_remove_can_io_isolation_if_set();
+
 	/*
 	 * Process pinctrl for the serial0 and serial3, aka WKUP_UART0 and
 	 * MAIN_UART1 modules and continue regardless of the result of pinctrl.
diff --git a/arch/arm/mach-k3/common.c b/arch/arm/mach-k3/common.c
index 0d070a8c95..a64f7e3cba 100644
--- a/arch/arm/mach-k3/common.c
+++ b/arch/arm/mach-k3/common.c
@@ -27,6 +27,9 @@
 #include <env.h>
 #include <elf.h>
 #include <soc.h>
+#include <wait_bit.h>
+
+#define CLKSTOP_TRANSITION_TIMEOUT_MS	10
 
 #if IS_ENABLED(CONFIG_SYS_K3_SPL_ATF)
 enum {
@@ -100,6 +103,59 @@ void mmr_unlock(phys_addr_t base, u32 partition)
 	writel(CTRLMMR_LOCK_KICK1_UNLOCK_VAL, part_base + CTRLMMR_LOCK_KICK1);
 }
 
+static void wkup_ctrl_remove_can_io_isolation(void)
+{
+	const void *wait_reg = (const void *)(WKUP_CTRL_MMR0_BASE +
+					      WKUP_CTRL_MMR_CANUART_WAKE_STAT1);
+	int ret;
+	u32 reg = 0;
+
+	/* Program magic word */
+	reg = readl(WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_CTRL);
+	reg |= WKUP_CTRL_MMR_CANUART_WAKE_CTRL_MW << WKUP_CTRL_MMR_CANUART_WAKE_CTRL_MW_SHIFT;
+	writel(reg, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_CTRL);
+
+	/* Set enable bit. */
+	reg |= WKUP_CTRL_MMR_CANUART_WAKE_CTRL_MW_LOAD_EN;
+	writel(reg, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_CTRL);
+
+       /* Clear enable bit. */
+	reg &= ~WKUP_CTRL_MMR_CANUART_WAKE_CTRL_MW_LOAD_EN;
+	writel(reg, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_CTRL);
+
+	/* wait for CAN_ONLY_IO signal to be 0 */
+	ret = wait_for_bit_32(wait_reg,
+			      WKUP_CTRL_MMR_CANUART_WAKE_STAT1_CANUART_IO_MODE,
+			      false,
+			      CLKSTOP_TRANSITION_TIMEOUT_MS,
+			      false);
+	if (ret < 0)
+		return;
+
+	/* Reset magic word */
+	writel(0, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_CTRL);
+
+	/* Remove WKUP IO isolation */
+	reg = readl(WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_PMCTRL_IO_0);
+	reg = reg & WKUP_CTRL_MMR_PMCTRL_IO_0_WRITE_MASK & ~WKUP_CTRL_MMR_PMCTRL_IO_0_GLOBAL_WUEN_0;
+	writel(reg, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_PMCTRL_IO_0);
+
+	/* clear global IO isolation */
+	reg = readl(WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_PMCTRL_IO_0);
+	reg = reg & WKUP_CTRL_MMR_PMCTRL_IO_0_WRITE_MASK & ~WKUP_CTRL_MMR_PMCTRL_IO_0_IO_ISO_CTRL_0;
+	writel(reg, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_PMCTRL_IO_0);
+
+	writel(0, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_DEEPSLEEP_CTRL);
+	writel(0, WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_PMCTRL_IO_GLB);
+}
+
+void wkup_ctrl_remove_can_io_isolation_if_set(void)
+{
+	if (readl(WKUP_CTRL_MMR0_BASE + WKUP_CTRL_MMR_CANUART_WAKE_STAT1) &
+	    WKUP_CTRL_MMR_CANUART_WAKE_STAT1_CANUART_IO_MODE)
+		wkup_ctrl_remove_can_io_isolation();
+}
+
 bool is_rom_loaded_sysfw(struct rom_extended_boot_data *data)
 {
 	if (strncmp(data->header, K3_ROM_BOOT_HEADER_MAGIC, 7))
diff --git a/arch/arm/mach-k3/common.h b/arch/arm/mach-k3/common.h
index e71c7453cb..4c0d4666d7 100644
--- a/arch/arm/mach-k3/common.h
+++ b/arch/arm/mach-k3/common.h
@@ -44,3 +44,4 @@ bool is_rom_loaded_sysfw(struct rom_extended_boot_data *data);
 enum k3_device_type get_device_type(void);
 void ti_secure_image_post_process(void **p_image, size_t *p_size);
 void ti_secure_image_check_binary(void **p_image, size_t *p_size);
+void wkup_ctrl_remove_can_io_isolation_if_set(void);
diff --git a/arch/arm/mach-k3/include/mach/hardware.h b/arch/arm/mach-k3/include/mach/hardware.h
index ca53b43962..20e9634513 100644
--- a/arch/arm/mach-k3/include/mach/hardware.h
+++ b/arch/arm/mach-k3/include/mach/hardware.h
@@ -102,6 +102,35 @@ K3_SOC_ID(am62px, AM62PX)
 #define CTRLMMR_LOCK_KICK1			0x100c
 #define CTRLMMR_LOCK_KICK1_UNLOCK_VAL		0xd172bc5a
 
+/*
+ * Shared WKUP_CTRL_MMR0 definitions used to remove IO isolation
+ */
+#define WKUP_CTRL_MMR_CANUART_WAKE_CTRL				0x18300
+#define WKUP_CTRL_MMR_CANUART_WAKE_CTRL_MW			0x2aaaaaaa
+#define WKUP_CTRL_MMR_CANUART_WAKE_CTRL_MW_SHIFT		1
+#define WKUP_CTRL_MMR_CANUART_WAKE_CTRL_MW_LOAD_EN		BIT(0)
+
+#define WKUP_CTRL_MMR_CANUART_WAKE_STAT1			0x1830c
+#define WKUP_CTRL_MMR_CANUART_WAKE_STAT1_CANUART_IO_MODE	BIT(0)
+
+#define WKUP_CTRL_MMR_PMCTRL_IO_0				0x18084
+#define WKUP_CTRL_MMR_PMCTRL_IO_0_ISOCLK_OVRD_0			BIT(0)
+#define WKUP_CTRL_MMR_PMCTRL_IO_0_ISOOVR_EXTEND_0		BIT(4)
+#define WKUP_CTRL_MMR_PMCTRL_IO_0_ISO_BYPASS_OVR_0		BIT(6)
+#define WKUP_CTRL_MMR_PMCTRL_IO_0_WUCLK_CTRL_0			BIT(8)
+#define WKUP_CTRL_MMR_PMCTRL_IO_0_GLOBAL_WUEN_0			BIT(16)
+#define WKUP_CTRL_MMR_PMCTRL_IO_0_IO_ISO_CTRL_0			BIT(24)
+#define WKUP_CTRL_MMR_PMCTRL_IO_0_WRITE_MASK ( \
+		WKUP_CTRL_MMR_PMCTRL_IO_0_ISOCLK_OVRD_0 |	\
+		WKUP_CTRL_MMR_PMCTRL_IO_0_ISOOVR_EXTEND_0 |	\
+		WKUP_CTRL_MMR_PMCTRL_IO_0_ISO_BYPASS_OVR_0 |	\
+		WKUP_CTRL_MMR_PMCTRL_IO_0_WUCLK_CTRL_0 |	\
+		WKUP_CTRL_MMR_PMCTRL_IO_0_GLOBAL_WUEN_0 |	\
+		WKUP_CTRL_MMR_PMCTRL_IO_0_IO_ISO_CTRL_0)
+
+#define WKUP_CTRL_MMR_PMCTRL_IO_GLB				0x1809c
+#define WKUP_CTRL_MMR_DEEPSLEEP_CTRL				0x18160
+
 #define K3_ROM_BOOT_HEADER_MAGIC	"EXTBOOT"
 
 struct rom_extended_boot_data {