mmc: mmci: stm32: add delay block support for STM32MP25

On STM32MP25, the delay block is inside the SoC, and configured through
the SYSCFG registers. The algorithm is also different from what was in
STM32MP1 chip.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Link: https://lore.kernel.org/r/20230619115120.64474-7-yann.gautier@foss.st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: Yann-lms

drivers/mmc/host/mmci_stm32_sdmmc.c

@@ -33,6 +33,20 @@
 #define DLYB_LNG_TIMEOUT_US	1000
 #define SDMMC_VSWEND_TIMEOUT_US 10000
 
+#define SYSCFG_DLYBSD_CR	0x0
+#define DLYBSD_CR_EN		BIT(0)
+#define DLYBSD_CR_RXTAPSEL_MASK	GENMASK(6, 1)
+#define DLYBSD_TAPSEL_NB	32
+#define DLYBSD_BYP_EN		BIT(16)
+#define DLYBSD_BYP_CMD		GENMASK(21, 17)
+#define DLYBSD_ANTIGLITCH_EN	BIT(22)
+
+#define SYSCFG_DLYBSD_SR	0x4
+#define DLYBSD_SR_LOCK		BIT(0)
+#define DLYBSD_SR_RXTAPSEL_ACK	BIT(1)
+
+#define DLYBSD_TIMEOUT_1S_IN_US	1000000
+
 struct sdmmc_lli_desc {
 	u32 idmalar;
 	u32 idmabase;
@@ -495,6 +509,46 @@ static int sdmmc_dlyb_mp15_prepare(struct mmci_host *host)
 	return 0;
 }
 
+static int sdmmc_dlyb_mp25_enable(struct sdmmc_dlyb *dlyb)
+{
+	u32 cr, sr;
+
+	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
+	cr |= DLYBSD_CR_EN;
+
+	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);
+
+	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
+					   sr, sr & DLYBSD_SR_LOCK, 1,
+					   DLYBSD_TIMEOUT_1S_IN_US);
+}
+
+static int sdmmc_dlyb_mp25_set_cfg(struct sdmmc_dlyb *dlyb,
+				   int unit __maybe_unused, int phase,
+				   bool sampler __maybe_unused)
+{
+	u32 cr, sr;
+
+	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
+	cr &= ~DLYBSD_CR_RXTAPSEL_MASK;
+	cr |= FIELD_PREP(DLYBSD_CR_RXTAPSEL_MASK, phase);
+
+	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);
+
+	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
+					  sr, sr & DLYBSD_SR_RXTAPSEL_ACK, 1,
+					  DLYBSD_TIMEOUT_1S_IN_US);
+}
+
+static int sdmmc_dlyb_mp25_prepare(struct mmci_host *host)
+{
+	struct sdmmc_dlyb *dlyb = host->variant_priv;
+
+	dlyb->max = DLYBSD_TAPSEL_NB;
+
+	return 0;
+}
+
 static int sdmmc_dlyb_phase_tuning(struct mmci_host *host, u32 opcode)
 {
 	struct sdmmc_dlyb *dlyb = host->variant_priv;
@@ -635,6 +689,12 @@ static struct sdmmc_tuning_ops dlyb_tuning_mp15_ops = {
 	.set_cfg = sdmmc_dlyb_mp15_set_cfg,
 };
 
+static struct sdmmc_tuning_ops dlyb_tuning_mp25_ops = {
+	.dlyb_enable = sdmmc_dlyb_mp25_enable,
+	.tuning_prepare = sdmmc_dlyb_mp25_prepare,
+	.set_cfg = sdmmc_dlyb_mp25_set_cfg,
+};
+
 void sdmmc_variant_init(struct mmci_host *host)
 {
 	struct device_node *np = host->mmc->parent->of_node;
@@ -653,7 +713,11 @@ void sdmmc_variant_init(struct mmci_host *host)
 		return;
 
 	dlyb->base = base_dlyb;
-	dlyb->ops = &dlyb_tuning_mp15_ops;
+	if (of_device_is_compatible(np, "st,stm32mp25-sdmmc2"))
+		dlyb->ops = &dlyb_tuning_mp25_ops;
+	else
+		dlyb->ops = &dlyb_tuning_mp15_ops;
+
 	host->variant_priv = dlyb;
 	host->mmc_ops->execute_tuning = sdmmc_execute_tuning;
 }