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* [RFC PATCH V3 11/21] mmc: sdhci: UHS-II support, export host operations to core
@ 2020-07-10 11:10 Ben Chuang
  0 siblings, 0 replies; only message in thread
From: Ben Chuang @ 2020-07-10 11:10 UTC (permalink / raw)
  To: adrian.hunter, ulf.hansson
  Cc: linux-mmc, linux-kernel, ben.chuang, takahiro.akashi, greg.tu,
	Ben Chuang

From: AKASHI Takahiro <takahiro.akashi@linaro.org>

Export sdhci-specific UHS-II operations to core.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
 drivers/mmc/host/sdhci.c | 70 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c2f6923d296c..aaf41954511a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2977,6 +2977,70 @@ static void sdhci_card_event(struct mmc_host *mmc)
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
+#if IS_ENABLED(CONFIG_MMC_SDHCI_UHS2)
+static int sdhci_uhs2_detect_init(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	int ret;
+
+	if (sdhci_uhs2_ops.do_detect_init)
+		ret = sdhci_uhs2_ops.do_detect_init(host);
+	else
+		return 0;
+
+	return ret;
+}
+
+static int sdhci_uhs2_set_reg(struct mmc_host *mmc, enum uhs2_act act)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	int ret;
+
+	if (sdhci_uhs2_ops.do_set_reg)
+		ret = sdhci_uhs2_ops.do_set_reg(host, act);
+	else
+		ret = 0;
+
+	return ret;
+}
+
+static void sdhci_uhs2_disable_clk(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+
+	clk &= ~SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+}
+
+static void sdhci_uhs2_enable_clk(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+	ktime_t timeout;
+
+	clk |= SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	/* Wait max 20 ms */
+	timeout = ktime_add_ms(ktime_get(), 20);
+	while (1) {
+		bool timedout = ktime_after(ktime_get(), timeout);
+
+		clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+		if (clk & SDHCI_CLOCK_INT_STABLE)
+			break;
+		if (timedout) {
+			pr_err("%s: Internal clock never stabilised.\n",
+			       mmc_hostname(host->mmc));
+			sdhci_dumpregs(host);
+			return;
+		}
+		udelay(10);
+	}
+}
+#endif /* CONFIG_MMC_SDHCI_UHS2 */
+
 static const struct mmc_host_ops sdhci_ops = {
 	.request	= sdhci_request,
 	.post_req	= sdhci_post_req,
@@ -2992,6 +3056,12 @@ static const struct mmc_host_ops sdhci_ops = {
 	.execute_tuning			= sdhci_execute_tuning,
 	.card_event			= sdhci_card_event,
 	.card_busy	= sdhci_card_busy,
+#if IS_ENABLED(CONFIG_MMC_SDHCI_UHS2)
+	.uhs2_detect_init	= sdhci_uhs2_detect_init,
+	.uhs2_set_reg		= sdhci_uhs2_set_reg,
+	.uhs2_disable_clk	= sdhci_uhs2_disable_clk,
+	.uhs2_enable_clk	= sdhci_uhs2_enable_clk,
+#endif /* CONFIG_MMC_SDHCI_UHS2 */
 };
 
 /*****************************************************************************\
-- 
2.27.0


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