[PATCH 2/4] mmc: fsl_esdhc: add workaround for erratum A-011334

[Michael Walle]

LS1028A SoCs are restricted in what divider values are allowed for HS400
mode. This is basically a port from the corresponding linux driver.

Signed-off-by: Michael Walle <michael at walle.cc>
---
 arch/arm/cpu/armv8/fsl-layerscape/Kconfig |  1 +
 drivers/mmc/Kconfig                       |  3 +++
 drivers/mmc/fsl_esdhc.c                   | 25 ++++++++++++++++++++++-
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
index ae0b7b21e8..c0190a233e 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
+++ b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
@@ -47,6 +47,7 @@ config ARCH_LS1028A
 	select SYS_FSL_ERRATUM_A009663 if !TFABOOT
 	select SYS_FSL_ERRATUM_A009942 if !TFABOOT
 	select SYS_FSL_ERRATUM_A050382
+	select SYS_FSL_ERRATUM_A011334
 	select RESV_RAM if GIC_V3_ITS
 	imply PANIC_HANG
 
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index f8ca52efb6..0b6755fd90 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -812,3 +812,6 @@ config SYS_FSL_ERRATUM_ESDHC135
 
 config SYS_FSL_ERRATUM_ESDHC_A001
 	bool
+
+config SYS_FSL_ERRATUM_A011334
+	bool
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index 6014e1c5ca..09ea1a9de9 100644
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -518,6 +518,24 @@ static void set_sysctl(struct fsl_esdhc_priv *priv, struct mmc *mmc, uint clock)
 	while (sdhc_clk / (div * pre_div) > clock && div < 16)
 		div++;
 
+	if (IS_ENABLED(CONFIG_SYS_FSL_ERRATUM_A011334) &&
+	    clock == 200000000 && mmc->selected_mode == MMC_HS_400) {
+		u32 div_ratio = pre_div * div;
+
+		if (div_ratio <= 4) {
+			pre_div = 4;
+			div = 1;
+		} else if (div_ratio <= 8) {
+			pre_div = 4;
+			div = 2;
+		} else if (div_ratio <= 12) {
+			pre_div = 4;
+			div = 3;
+		} else {
+			printf("unsupported clock division.\n");
+		}
+	}
+
 	mmc->clock = sdhc_clk / pre_div / div;
 	priv->clock = mmc->clock;
 
@@ -1063,9 +1081,14 @@ static int fsl_esdhc_execute_tuning(struct udevice *dev, uint32_t opcode)
 	struct fsl_esdhc_plat *plat = dev_get_plat(dev);
 	struct fsl_esdhc_priv *priv = dev_get_priv(dev);
 	struct fsl_esdhc *regs = priv->esdhc_regs;
+	struct mmc *mmc = &plat->mmc;
 	u32 val, irqstaten;
 	int i;
 
+	if (IS_ENABLED(CONFIG_SYS_FSL_ERRATUM_A011334) &&
+	    plat->mmc.hs400_tuning)
+		set_sysctl(priv, mmc, mmc->clock);
+
 	esdhc_tuning_block_enable(priv, true);
 	esdhc_setbits32(&regs->autoc12err, EXECUTE_TUNING);
 
@@ -1073,7 +1096,7 @@ static int fsl_esdhc_execute_tuning(struct udevice *dev, uint32_t opcode)
 	esdhc_write32(&regs->irqstaten, IRQSTATEN_BRR);
 
 	for (i = 0; i < MAX_TUNING_LOOP; i++) {
-		mmc_send_tuning(&plat->mmc, opcode, NULL);
+		mmc_send_tuning(mmc, opcode, NULL);
 		mdelay(1);
 
 		val = esdhc_read32(&regs->autoc12err);
-- 
2.20.1