[PATCH] ddr: imx8m: Return error values from LPDDR4 training

[Schrempf Frieder]

From: Frieder Schrempf <frieder.schrempf at kontron.de>

In cases when the same SPL should run on boards with i.MX8MM, that
differ in DDR configuration, it is necessary to try different
parameters and check if the training done by the firmware suceeds or
not.

Therefore we return the DDR training/initialization success to the
upper layer in order to be able to retry with different settings if
necessary.

Signed-off-by: Frieder Schrempf <frieder.schrempf at kontron.de>
---
 arch/arm/include/asm/arch-imx8m/ddr.h |  6 +++---
 drivers/ddr/imx/imx8m/ddr_init.c      | 11 +++++++++--
 drivers/ddr/imx/imx8m/ddrphy_train.c  |  9 +++++++--
 drivers/ddr/imx/imx8m/ddrphy_utils.c  |  8 ++++----
 4 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/arch/arm/include/asm/arch-imx8m/ddr.h b/arch/arm/include/asm/arch-imx8m/ddr.h
index 53d46256d8..7a2a2d8edc 100644
--- a/arch/arm/include/asm/arch-imx8m/ddr.h
+++ b/arch/arm/include/asm/arch-imx8m/ddr.h
@@ -703,14 +703,14 @@ struct dram_timing_info {
 extern struct dram_timing_info dram_timing;
 
 void ddr_load_train_firmware(enum fw_type type);
-void ddr_init(struct dram_timing_info *timing_info);
-void ddr_cfg_phy(struct dram_timing_info *timing_info);
+int ddr_init(struct dram_timing_info *timing_info);
+int ddr_cfg_phy(struct dram_timing_info *timing_info);
 void load_lpddr4_phy_pie(void);
 void ddrphy_trained_csr_save(struct dram_cfg_param *param, unsigned int num);
 void dram_config_save(struct dram_timing_info *info, unsigned long base);
 
 /* utils function for ddr phy training */
-void wait_ddrphy_training_complete(void);
+int wait_ddrphy_training_complete(void);
 void ddrphy_init_set_dfi_clk(unsigned int drate);
 void ddrphy_init_read_msg_block(enum fw_type type);
 
diff --git a/drivers/ddr/imx/imx8m/ddr_init.c b/drivers/ddr/imx/imx8m/ddr_init.c
index d6e915c9b9..e927f0896d 100644
--- a/drivers/ddr/imx/imx8m/ddr_init.c
+++ b/drivers/ddr/imx/imx8m/ddr_init.c
@@ -20,9 +20,10 @@ void ddr_cfg_umctl2(struct dram_cfg_param *ddrc_cfg, int num)
 	}
 }
 
-void ddr_init(struct dram_timing_info *dram_timing)
+int ddr_init(struct dram_timing_info *dram_timing)
 {
 	unsigned int tmp, initial_drate, target_freq;
+	int ret;
 
 	printf("DDRINFO: start DRAM init\n");
 
@@ -98,7 +99,11 @@ void ddr_init(struct dram_timing_info *dram_timing)
 	 * accessing relevant PUB registers
 	 */
 	debug("DDRINFO:ddrphy config start\n");
-	ddr_cfg_phy(dram_timing);
+
+	ret = ddr_cfg_phy(dram_timing);
+	if (ret)
+		return ret;
+
 	debug("DDRINFO: ddrphy config done\n");
 
 	/*
@@ -165,4 +170,6 @@ void ddr_init(struct dram_timing_info *dram_timing)
 
 	/* save the dram timing config into memory */
 	dram_config_save(dram_timing, CONFIG_SAVED_DRAM_TIMING_BASE);
+
+	return 0;
 }
diff --git a/drivers/ddr/imx/imx8m/ddrphy_train.c b/drivers/ddr/imx/imx8m/ddrphy_train.c
index 18f7ed7fea..306af82504 100644
--- a/drivers/ddr/imx/imx8m/ddrphy_train.c
+++ b/drivers/ddr/imx/imx8m/ddrphy_train.c
@@ -8,13 +8,14 @@
 #include <asm/arch/ddr.h>
 #include <asm/arch/lpddr4_define.h>
 
-void ddr_cfg_phy(struct dram_timing_info *dram_timing)
+int ddr_cfg_phy(struct dram_timing_info *dram_timing)
 {
 	struct dram_cfg_param *dram_cfg;
 	struct dram_fsp_msg *fsp_msg;
 	unsigned int num;
 	int i = 0;
 	int j = 0;
+	int ret;
 
 	/* initialize PHY configuration */
 	dram_cfg = dram_timing->ddrphy_cfg;
@@ -60,7 +61,9 @@ void ddr_cfg_phy(struct dram_timing_info *dram_timing)
 		dwc_ddrphy_apb_wr(0xd0099, 0x0);
 
 		/* Wait for the training firmware to complete */
-		wait_ddrphy_training_complete();
+		ret = wait_ddrphy_training_complete();
+		if (ret)
+			return ret;
 
 		/* Halt the microcontroller. */
 		dwc_ddrphy_apb_wr(0xd0099, 0x1);
@@ -83,4 +86,6 @@ void ddr_cfg_phy(struct dram_timing_info *dram_timing)
 
 	/* save the ddr PHY trained CSR in memory for low power use */
 	ddrphy_trained_csr_save(ddrphy_trained_csr, ddrphy_trained_csr_num);
+
+	return 0;
 }
diff --git a/drivers/ddr/imx/imx8m/ddrphy_utils.c b/drivers/ddr/imx/imx8m/ddrphy_utils.c
index e60503309e..863fb43897 100644
--- a/drivers/ddr/imx/imx8m/ddrphy_utils.c
+++ b/drivers/ddr/imx/imx8m/ddrphy_utils.c
@@ -84,7 +84,7 @@ static inline void decode_streaming_message(void)
 	debug("\n");
 }
 
-void wait_ddrphy_training_complete(void)
+int wait_ddrphy_training_complete(void)
 {
 	unsigned int mail;
 
@@ -95,10 +95,10 @@ void wait_ddrphy_training_complete(void)
 			decode_streaming_message();
 		} else if (mail == 0x07) {
 			debug("Training PASS\n");
-			break;
+			return 0;
 		} else if (mail == 0xff) {
-			printf("Training FAILED\n");
-			break;
+			debug("Training FAILED\n");
+			return -1;
 		}
 	}
 }
-- 
2.17.1