[PATCH] mmc: renesas_sdhi: Fix card initialization failure in high speed mode

[marek.vasut@gmail.com]

From: Takeshi Saito <takeshi.saito.xv@renesas.com>

This fixes card initialization failure in high speed mode.

If U-Boot uses SDR or HS200/400 mode before starting Linux and Linux
DT does not enable SDR/HS200/HS400 mode, card initialization fails in
high speed mode.

It is necessary to initialize SCC registers during card initialization
phase. HW reset function is registered only for a port with either of
SDR/HS200/HS400 properties in device tree. If SDR/HS200/HS400 properties
are not present in device tree, SCC registers will not be reset. In SoC
that support SCC registers, HW reset function should be registered
regardless of the configuration of device tree.

Reproduction procedure:
- Use U-Boot that support MMC HS200/400 mode.
- Delete HS200/HS400 properties in device tree.
  (Delete mmc-hs200-1_8v and mmc-hs400-1_8v)
- MMC port works high speed mode and all commands fail.

Signed-off-by: Takeshi Saito <takeshi.saito.xv@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-renesas-soc@vger.kernel.org
To: linux-mmc@vger.kernel.org
--
NOTE: Marek: - Reworded commit message
             - Updated patch to next/master
---
 drivers/mmc/host/renesas_sdhi_core.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 31a351a20dc0..7e2a75c4f36f 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -723,6 +723,13 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 		host->ops.start_signal_voltage_switch =
 			renesas_sdhi_start_signal_voltage_switch;
 		host->sdcard_irq_setbit_mask = TMIO_STAT_ALWAYS_SET_27;
+
+		/* SDR and HS200/400 registers requires HW reset */
+		if (of_data && of_data->scc_offset) {
+			priv->scc_ctl = host->ctl + of_data->scc_offset;
+			host->mmc->caps |= MMC_CAP_HW_RESET;
+			host->hw_reset = renesas_sdhi_hw_reset;
+		}
 	}
 
 	/* Orginally registers were 16 bit apart, could be 32 or 64 nowadays */
@@ -775,8 +782,6 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 		const struct renesas_sdhi_scc *taps = of_data->taps;
 		bool hit = false;
 
-		host->mmc->caps |= MMC_CAP_HW_RESET;
-
 		for (i = 0; i < of_data->taps_num; i++) {
 			if (taps[i].clk_rate == 0 ||
 			    taps[i].clk_rate == host->mmc->f_max) {
@@ -789,12 +794,10 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 		if (!hit)
 			dev_warn(&host->pdev->dev, "Unknown clock rate for SDR104\n");
 
-		priv->scc_ctl = host->ctl + of_data->scc_offset;
 		host->init_tuning = renesas_sdhi_init_tuning;
 		host->prepare_tuning = renesas_sdhi_prepare_tuning;
 		host->select_tuning = renesas_sdhi_select_tuning;
 		host->check_scc_error = renesas_sdhi_check_scc_error;
-		host->hw_reset = renesas_sdhi_hw_reset;
 		host->prepare_hs400_tuning =
 			renesas_sdhi_prepare_hs400_tuning;
 		host->hs400_downgrade = renesas_sdhi_disable_scc;
-- 
2.19.2