[PATCH v18 05/12] mmc: renesas_sdhi: Add tuning delay support for RZ/G2L

[Biju]

From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>

Some SoCs, starting with RZ/G2L, require a hardware adjustment delay to be
written to SCC_TMPPORT2 when switching signal voltage during tuning. The
register value differs by voltage: 0x1 for 1.8 V and 0x0 for 3.3 V.

Introduce TMIO_MMC_TUNING_DELAY flag (bit 13) in tmio.h to identify
controllers that need this behaviour. Add
renesas_sdhi_set_hw_adjustment_delay(), which writes the appropriate
value to SCC_TMPPORT2 when the flag is set, and call it from
renesas_sdhi_start_signal_voltage_switch() after the regulator is
configured. Additionally, reset SCC_TMPPORT2 to 0 at the start of
renesas_sdhi_execute_tuning() when the flag is set and tap_num is 8.

Introduce a dedicated of_data_rz_g2l descriptor carrying the new flag
alongside RZ/G2L-specific capabilities, and wire of_rzg2l_compatible
to it instead of the generic R-Car Gen3 descriptor.

Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v18:
 * New patch.
---
 drivers/mmc/host/renesas_sdhi_core.c          | 86 +++++++++++--------
 drivers/mmc/host/renesas_sdhi_internal_dmac.c | 21 ++++-
 include/linux/platform_data/tmio.h            |  3 +
 3 files changed, 75 insertions(+), 35 deletions(-)

diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 7e48e78cbfab..e9767aa83b00 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -256,40 +256,6 @@ static int renesas_sdhi_card_busy(struct mmc_host *mmc)
 		 TMIO_STAT_DAT0);
 }
 
-static int renesas_sdhi_start_signal_voltage_switch(struct mmc_host *mmc,
-						    struct mmc_ios *ios)
-{
-	struct tmio_mmc_host *host = mmc_priv(mmc);
-	struct renesas_sdhi *priv = host_to_priv(host);
-	struct pinctrl_state *pin_state;
-	int ret;
-
-	switch (ios->signal_voltage) {
-	case MMC_SIGNAL_VOLTAGE_330:
-		pin_state = priv->pins_default;
-		break;
-	case MMC_SIGNAL_VOLTAGE_180:
-		pin_state = priv->pins_uhs;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	/*
-	 * If anything is missing, assume signal voltage is fixed at
-	 * 3.3V and succeed/fail accordingly.
-	 */
-	if (IS_ERR(priv->pinctrl) || IS_ERR(pin_state))
-		return ios->signal_voltage ==
-			MMC_SIGNAL_VOLTAGE_330 ? 0 : -EINVAL;
-
-	ret = mmc_regulator_set_vqmmc(host->mmc, ios);
-	if (ret < 0)
-		return ret;
-
-	return pinctrl_select_state(priv->pinctrl, pin_state);
-}
-
 /* SCC registers */
 #define SH_MOBILE_SDHI_SCC_DTCNTL	0x000
 #define SH_MOBILE_SDHI_SCC_TAPSET	0x002
@@ -350,6 +316,55 @@ static inline void sd_scc_write32(struct tmio_mmc_host *host,
 	writel(val, priv->scc_ctl + (addr << host->bus_shift));
 }
 
+static void renesas_sdhi_set_hw_adjustment_delay(struct tmio_mmc_host *host)
+{
+	struct renesas_sdhi *priv = host_to_priv(host);
+
+	if (!(host->pdata->flags & TMIO_MMC_TUNING_DELAY))
+		return;
+
+	if (host->mmc->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330)
+		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, 0x0);
+	else
+		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, 0x1);
+}
+
+static int renesas_sdhi_start_signal_voltage_switch(struct mmc_host *mmc,
+						    struct mmc_ios *ios)
+{
+	struct tmio_mmc_host *host = mmc_priv(mmc);
+	struct renesas_sdhi *priv = host_to_priv(host);
+	struct pinctrl_state *pin_state;
+	int ret;
+
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
+		pin_state = priv->pins_default;
+		break;
+	case MMC_SIGNAL_VOLTAGE_180:
+		pin_state = priv->pins_uhs;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * If anything is missing, assume signal voltage is fixed at
+	 * 3.3V and succeed/fail accordingly.
+	 */
+	if (IS_ERR(priv->pinctrl) || IS_ERR(pin_state))
+		return ios->signal_voltage ==
+			MMC_SIGNAL_VOLTAGE_330 ? 0 : -EINVAL;
+
+	ret = mmc_regulator_set_vqmmc(host->mmc, ios);
+	if (ret < 0)
+		return ret;
+
+	renesas_sdhi_set_hw_adjustment_delay(host);
+
+	return pinctrl_select_state(priv->pinctrl, pin_state);
+}
+
 static unsigned int renesas_sdhi_init_tuning(struct tmio_mmc_host *host)
 {
 	struct renesas_sdhi *priv;
@@ -709,6 +724,9 @@ static int renesas_sdhi_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	if (!priv->tap_num)
 		return 0; /* Tuning is not supported */
 
+	if ((host->pdata->flags & TMIO_MMC_TUNING_DELAY) && priv->tap_num == 8)
+		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, 0);
+
 	if (priv->tap_num * 2 >= sizeof(priv->taps) * BITS_PER_BYTE) {
 		dev_err(&host->pdev->dev,
 			"Too many taps, please update 'taps' in tmio_mmc_host!\n");
diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
index c91b910488da..93219706a4d6 100644
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -143,6 +143,25 @@ static const struct renesas_sdhi_of_data of_data_rcar_gen3_no_sdh_fallback = {
 	.max_divider	= SDHI_MAX_DIVIDER_DEFAULT,
 };
 
+static const struct renesas_sdhi_of_data of_data_rz_g2l = {
+	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
+			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2 |
+			  TMIO_MMC_64BIT_DATA_PORT | TMIO_MMC_TUNING_DELAY,
+	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
+			  MMC_CAP_CMD23 | MMC_CAP_WAIT_WHILE_BUSY,
+	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT | MMC_CAP2_MERGE_CAPABLE,
+	.bus_shift	= 2,
+	.scc_offset	= 0x1000,
+	.taps		= rcar_gen3_scc_taps,
+	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
+	/* DMAC can handle 32bit blk count but only 1 segment */
+	.max_blk_count	= UINT_MAX / TMIO_MAX_BLK_SIZE,
+	.max_segs	= 1,
+	.sdhi_flags	= SDHI_FLAG_NEED_CLKH_FALLBACK,
+	.clk_mask	= SDHI_CLK_MASK_DEFAULT,
+	.max_divider	= SDHI_MAX_DIVIDER_DEFAULT,
+};
+
 static const u8 r8a7796_es13_calib_table[2][SDHI_CALIB_TABLE_MAX] = {
 	{ 3,  3,  3,  3,  3,  3,  3,  4,  4,  5,  6,  7,  8,  9, 10, 15,
 	 16, 16, 16, 16, 16, 16, 17, 18, 18, 19, 20, 21, 22, 23, 24, 25 },
@@ -264,7 +283,7 @@ static const struct renesas_sdhi_of_data_with_quirks of_r8a77990_compatible = {
 };
 
 static const struct renesas_sdhi_of_data_with_quirks of_rzg2l_compatible = {
-	.of_data = &of_data_rcar_gen3,
+	.of_data = &of_data_rz_g2l,
 	.quirks = &sdhi_quirks_rzg2l,
 };
 
diff --git a/include/linux/platform_data/tmio.h b/include/linux/platform_data/tmio.h
index 27ea21c00419..868a21842fa5 100644
--- a/include/linux/platform_data/tmio.h
+++ b/include/linux/platform_data/tmio.h
@@ -50,6 +50,9 @@
 /* Some controllers have a 64-bit wide data port register */
 #define TMIO_MMC_64BIT_DATA_PORT	BIT(12)
 
+/* Some controllers have tuning delay */
+#define TMIO_MMC_TUNING_DELAY		BIT(13)
+
 struct tmio_mmc_data {
 	void				*chan_priv_tx;
 	void				*chan_priv_rx;
-- 
2.43.0