[PATCH v22 12/13] mmc: renesas_sdhi: Add RZ/G3L HS400 support

[Biju]

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

Add HS400 support for the RZ/G3L SoC.

RZ/G3L needs a second HS400 enable register, SDm_SCC_HS400MODE2
(offset 0x020), alongside the existing TMPPORT2 path. Add a
TMIO_MMC_HS400MODE2 flag (bit 16) for controllers that need it.

renesas_sdhi_hs400_complete() now also sets HS400EN2 in HS400MODE2
when the flag is set, and renesas_sdhi_reset_hs400_mode() clears it
on exit. Add renesas_sdhi_set_tmpport() to mask off only the lower
16 bits (TMPOUT) of TMPPORT2 when writing it, preserving the upper
bits on controllers with HS400MODE2, instead of the previous
unconditional zero write.

RZ/G3L HS400 supports only one divider value, so
renesas_sdhi_set_clock() now forces the clock value to 0 before
masking when HS400MODE2 is set and the internal divider isn't
currently enabled, rejecting any other divider. This also completes
renesas_sdhi_is_internal_divider_enabled() from earlier in the
series, which now additionally checks that the current timing mode
is not MMC_TIMING_MMC_HS400 before reporting the internal divider as
enabled.

Enable TMIO_MMC_HS400MODE2 in of_data_rzg3l to complete RZ/G3L HS400
support.

Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v21->v22:
 * Updated commit description
 * Added a renesas_sdhi_set_tmpport() helper to set delay values.
 * Added a check in renesas_sdhi_is_internal_divider_enabled() to
   return disabled status when in HS400 mode.
v20->v21:
 * Updated renesas_sdhi_set_clock() for RZ/G3L HS400 clock handling as
   it supports only single clk divider value and other values are
   prohibited.
 * Updated commit description.
v19->v20:
 * No change.
v18->v19:
 * Updated commit description.
 * Fixed extra space in HS400MODE2 comment block.
 * Updated the comment HS400mode2->HS400MODE2.
 * Dropped the updation of clk handling as it is taken care in
   previous patches.
v18:
 * New patch.
---
 drivers/mmc/host/renesas_sdhi_core.c          | 42 +++++++++++++++++--
 drivers/mmc/host/renesas_sdhi_internal_dmac.c |  3 +-
 include/linux/platform_data/tmio.h            |  3 ++
 3 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 0d38fbc53512..541321e43a13 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -132,7 +132,8 @@ static bool renesas_sdhi_is_internal_divider_enabled(struct tmio_mmc_host *host)
 {
 	bool enable = false;
 
-	if (host->pdata->flags & TMIO_MMC_INTERNAL_DIVIDER)
+	if ((host->pdata->flags & TMIO_MMC_INTERNAL_DIVIDER) &&
+	    host->mmc->ios.timing != MMC_TIMING_MMC_HS400)
 		enable = true;
 
 	return enable;
@@ -252,6 +253,14 @@ static void renesas_sdhi_set_clock(struct tmio_mmc_host *host,
 			clk &= ~0xff;
 	}
 
+	/*
+	 * RZ/G3L SoC HS400 mode has only 1 divider value.
+	 * Other divider values are prohibited
+	 */
+	if ((host->pdata->flags & TMIO_MMC_HS400MODE2) &&
+	    !renesas_sdhi_is_internal_divider_enabled(host))
+		clk = 0;
+
 	clock = clk & host->pdata->clk_div_mask;
 	if (clock != CLK_CTL_DIV_MASK)
 		host->mmc->actual_clock /= (1 << (ffs(clock) + 1));
@@ -309,6 +318,7 @@ static int renesas_sdhi_card_busy(struct mmc_host *mmc)
 #define SH_MOBILE_SDHI_SCC_TMPPORT5	0x018
 #define SH_MOBILE_SDHI_SCC_TMPPORT6	0x01A
 #define SH_MOBILE_SDHI_SCC_TMPPORT7	0x01C
+#define RZG3L_SDHI_SCC_HS400MODE2	0x020
 #define RZG3L_SDHI_SCC_HWADJ4		0x022
 
 #define SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN		BIT(0)
@@ -341,6 +351,7 @@ static int renesas_sdhi_card_busy(struct mmc_host *mmc)
 #define SH_MOBILE_SDHI_SCC_TMPPORT_DISABLE_WP_CODE	0xa5000000
 #define SH_MOBILE_SDHI_SCC_TMPPORT_CALIB_CODE_MASK	0x1f
 #define SH_MOBILE_SDHI_SCC_TMPPORT_MANUAL_MODE		BIT(7)
+#define RZG3L_SDHI_SCC_HS400MODE2_HS400EN2		BIT(0)
 
 static inline u32 sd_scc_read32(struct tmio_mmc_host *host,
 				struct renesas_sdhi *priv, int addr)
@@ -355,6 +366,22 @@ 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_tmpport(struct tmio_mmc_host *host, u32 tmpport)
+{
+	struct renesas_sdhi *priv = host_to_priv(host);
+	u32 val;
+
+	if (host->pdata->flags & TMIO_MMC_HS400MODE2) {
+		val = sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2);
+		val &= ~GENMASK(15, 0); /* TMPOUT MASK */
+		val |= tmpport;
+	} else {
+		val = tmpport;
+	}
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, val);
+}
+
 static void renesas_sdhi_set_hw_adjustment_delay(struct tmio_mmc_host *host)
 {
 	struct renesas_sdhi *priv = host_to_priv(host);
@@ -364,11 +391,11 @@ static void renesas_sdhi_set_hw_adjustment_delay(struct tmio_mmc_host *host)
 		return;
 
 	if (host->mmc->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
-		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, 0x0);
+		renesas_sdhi_set_tmpport(host, 0x0);
 		if (hwadj2)
 			sd_scc_write32(host, priv, RZG3L_SDHI_SCC_HWADJ2, 0x3FFF);
 	} else {
-		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2, 0x1);
+		renesas_sdhi_set_tmpport(host, 0x1);
 		if (hwadj2)
 			sd_scc_write32(host, priv, RZG3L_SDHI_SCC_HWADJ2, 0xFF);
 	}
@@ -477,6 +504,10 @@ static void renesas_sdhi_hs400_complete(struct mmc_host *mmc)
 			host->pdata->osel_tmpout) |
 			sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2));
 
+	if (host->pdata->flags & TMIO_MMC_HS400MODE2)
+		sd_scc_write32(host, priv, RZG3L_SDHI_SCC_HS400MODE2,
+			       RZG3L_SDHI_SCC_HS400MODE2_HS400EN2);
+
 	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL,
 		       SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN |
 		       sd_scc_read32(host, priv,
@@ -618,6 +649,9 @@ static void renesas_sdhi_reset_hs400_mode(struct tmio_mmc_host *host,
 			 host->pdata->osel_tmpout) &
 			sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2));
 
+	if (host->pdata->flags & TMIO_MMC_HS400MODE2)
+		sd_scc_write32(host, priv, RZG3L_SDHI_SCC_HS400MODE2, 0x0);
+
 	if (sdhi_has_quirk(priv, hs400_calib_table) || sdhi_has_quirk(priv, hs400_bad_taps))
 		renesas_sdhi_adjust_hs400_mode_disable(host);
 
@@ -776,7 +810,7 @@ static int renesas_sdhi_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		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);
+		renesas_sdhi_set_tmpport(host, 0);
 
 	if (priv->tap_num * 2 >= sizeof(priv->taps) * BITS_PER_BYTE) {
 		dev_err(&host->pdev->dev,
diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
index b1146dca94ca..8cd3ced88b81 100644
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -178,7 +178,8 @@ static const struct renesas_sdhi_of_data of_data_rzg3l = {
 	.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 |
-			  TMIO_MMC_INTERNAL_DIVIDER | TMIO_MMC_HWADJ,
+			  TMIO_MMC_INTERNAL_DIVIDER | TMIO_MMC_HWADJ |
+			  TMIO_MMC_HS400MODE2,
 	.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,
diff --git a/include/linux/platform_data/tmio.h b/include/linux/platform_data/tmio.h
index 501ca4355c34..81a37d6baefc 100644
--- a/include/linux/platform_data/tmio.h
+++ b/include/linux/platform_data/tmio.h
@@ -59,6 +59,9 @@
 /* Some controllers have hw adjustment delay */
 #define TMIO_MMC_HWADJ			BIT(15)
 
+/* Some controllers have HS400MODE2 */
+#define TMIO_MMC_HS400MODE2		BIT(16)
+
 struct tmio_mmc_data {
 	void				*chan_priv_tx;
 	void				*chan_priv_rx;
-- 
2.43.0