[PATCH 02/10] arm: K3: sysfw-loader: Add a config_pm_pre_callback()

[Faiz Abbas]

System firmware does not guarantee that clocks going out of the device
will be stable during power management configuration. There are some
DCRC errors when SPL tries to get the next stage during eMMC boot after
sysfw pm configuration.

Therefore add a config_pm_pre_callback() to switch off the eMMC clock
before power management and restart it after it is done.

Signed-off-by: Faiz Abbas <faiz_abbas at ti.com>
---
 arch/arm/mach-k3/am6_init.c                  | 33 +++++++++++++++++++-
 arch/arm/mach-k3/include/mach/sysfw-loader.h |  2 +-
 arch/arm/mach-k3/j721e_init.c                | 33 +++++++++++++++++++-
 arch/arm/mach-k3/sysfw-loader.c              |  6 +++-
 4 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-k3/am6_init.c b/arch/arm/mach-k3/am6_init.c
index 8d107b870b..9d3c62b3f4 100644
--- a/arch/arm/mach-k3/am6_init.c
+++ b/arch/arm/mach-k3/am6_init.c
@@ -17,6 +17,7 @@
 #include <dm/uclass-internal.h>
 #include <dm/pinctrl.h>
 #include <linux/soc/ti/ti_sci_protocol.h>
+#include <mmc.h>
 
 #ifdef CONFIG_SPL_BUILD
 #ifdef CONFIG_K3_LOAD_SYSFW
@@ -86,6 +87,33 @@ static void store_boot_index_from_rom(void)
 	bootindex = *(u32 *)(CONFIG_SYS_K3_BOOT_PARAM_TABLE_INDEX);
 }
 
+#if defined(CONFIG_K3_LOAD_SYSFW)
+void k3_mmc_stop_clock(void)
+{
+	if (spl_boot_device() == BOOT_DEVICE_MMC1) {
+		struct mmc *mmc = find_mmc_device(0);
+
+		if (!mmc)
+			return;
+
+		mmc->saved_clock = mmc->clock;
+		mmc_set_clock(mmc, 0, true);
+	}
+}
+
+void k3_mmc_restart_clock(void)
+{
+	if (spl_boot_device() == BOOT_DEVICE_MMC1) {
+		struct mmc *mmc = find_mmc_device(0);
+
+		if (!mmc)
+			return;
+
+		mmc_set_clock(mmc, mmc->saved_clock, false);
+	}
+}
+#endif
+
 void board_init_f(ulong dummy)
 {
 #if defined(CONFIG_K3_LOAD_SYSFW) || defined(CONFIG_K3_AM654_DDRSS)
@@ -128,7 +156,10 @@ void board_init_f(ulong dummy)
 	 * callback hook, effectively switching on (or over) the console
 	 * output.
 	 */
-	k3_sysfw_loader(preloader_console_init);
+	k3_sysfw_loader(k3_mmc_stop_clock, k3_mmc_restart_clock);
+
+	/* Prepare console output */
+	preloader_console_init();
 
 	/* Disable ROM configured firewalls right after loading sysfw */
 #ifdef CONFIG_TI_SECURE_DEVICE
diff --git a/arch/arm/mach-k3/include/mach/sysfw-loader.h b/arch/arm/mach-k3/include/mach/sysfw-loader.h
index 36eb265348..6f5612b4fd 100644
--- a/arch/arm/mach-k3/include/mach/sysfw-loader.h
+++ b/arch/arm/mach-k3/include/mach/sysfw-loader.h
@@ -7,6 +7,6 @@
 #ifndef _SYSFW_LOADER_H_
 #define _SYSFW_LOADER_H_
 
-void k3_sysfw_loader(void (*config_pm_done_callback)(void));
+void k3_sysfw_loader(void (*config_pm_pre_callback)(void), void (*config_pm_done_callback)(void));
 
 #endif
diff --git a/arch/arm/mach-k3/j721e_init.c b/arch/arm/mach-k3/j721e_init.c
index f7f7398081..0994522f6c 100644
--- a/arch/arm/mach-k3/j721e_init.c
+++ b/arch/arm/mach-k3/j721e_init.c
@@ -18,6 +18,7 @@
 #include <dm.h>
 #include <dm/uclass-internal.h>
 #include <dm/pinctrl.h>
+#include <mmc.h>
 
 #ifdef CONFIG_SPL_BUILD
 #ifdef CONFIG_K3_LOAD_SYSFW
@@ -100,6 +101,33 @@ static void ctrl_mmr_unlock(void)
 	mmr_unlock(CTRL_MMR0_BASE, 7);
 }
 
+#if defined(CONFIG_K3_LOAD_SYSFW)
+void k3_mmc_stop_clock(void)
+{
+	if (spl_boot_device() == BOOT_DEVICE_MMC1) {
+		struct mmc *mmc = find_mmc_device(0);
+
+		if (!mmc)
+			return;
+
+		mmc->saved_clock = mmc->clock;
+		mmc_set_clock(mmc, 0, true);
+	}
+}
+
+void k3_mmc_restart_clock(void)
+{
+	if (spl_boot_device() == BOOT_DEVICE_MMC1) {
+		struct mmc *mmc = find_mmc_device(0);
+
+		if (!mmc)
+			return;
+
+		mmc_set_clock(mmc, mmc->saved_clock, false);
+	}
+}
+#endif
+
 /*
  * This uninitialized global variable would normal end up in the .bss section,
  * but the .bss is cleared between writing and reading this variable, so move
@@ -154,7 +182,10 @@ void board_init_f(ulong dummy)
 	 * callback hook, effectively switching on (or over) the console
 	 * output.
 	 */
-	k3_sysfw_loader(preloader_console_init);
+	k3_sysfw_loader(k3_mmc_stop_clock, k3_mmc_restart_clock);
+
+	/* Prepare console output */
+	preloader_console_init();
 
 	/* Disable ROM configured firewalls right after loading sysfw */
 #ifdef CONFIG_TI_SECURE_DEVICE
diff --git a/arch/arm/mach-k3/sysfw-loader.c b/arch/arm/mach-k3/sysfw-loader.c
index 5903bbe12a..8386499ed6 100644
--- a/arch/arm/mach-k3/sysfw-loader.c
+++ b/arch/arm/mach-k3/sysfw-loader.c
@@ -172,7 +172,8 @@ static void k3_sysfw_configure_using_fit(void *fit,
 		      ret);
 }
 
-void k3_sysfw_loader(void (*config_pm_done_callback)(void))
+void k3_sysfw_loader(void (*config_pm_pre_callback) (void),
+		     void (*config_pm_done_callback)(void))
 {
 	struct spl_image_info spl_image = { 0 };
 	struct spl_boot_device bootdev = { 0 };
@@ -264,6 +265,9 @@ void k3_sysfw_loader(void (*config_pm_done_callback)(void))
 	/* Parse and apply the different SYSFW configuration fragments */
 	k3_sysfw_configure_using_fit(sysfw_load_address, ti_sci);
 
+	if (config_pm_pre_callback)
+		config_pm_pre_callback();
+
 	/*
 	 * Now that all clocks and PM aspects are setup, invoke a user-
 	 * provided callback function. Usually this callback would be used
-- 
2.19.2