[PATCH v2 1/4] mmc: core: switch to 1V8 or 1V2 for hs400es mode

[PATCH v2 1/4] mmc: core: switch to 1V8 or 1V2 for hs400es mode

[Shawn Lin]

When introducing hs400es, I didn't notice that we haven't
switched voltage to 1V2 or 1V8 for it. That happens to work
as the first controller claiming to support hs400es, arasan(5.1),
which is designed to only support 1V8. So the voltage is fixed to 1V8.
But it actually is wrong, and will not fit for other host controllers.
Let's fix it.

Fixes: commit 81ac2af65793ecf ("mmc: core: implement enhanced strobe support")
Cc: <stable@vger.kernel.org> 4.4#
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

---

Changes in v2:
- fix copy-paste error, mea culpa

 drivers/mmc/core/mmc.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 3486bc7..f4ed5ac 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1263,6 +1263,16 @@ static int mmc_select_hs400es(struct mmc_card *card)
 		goto out_err;
 	}
 
+	if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400_1_2V)
+		err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120);
+
+	if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400_1_8V)
+		err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
+
+	/* If fails try again during next card power cycle */
+	if (err)
+		goto out_err;
+
 	err = mmc_select_bus_width(card);
 	if (err < 0)
 		goto out_err;
-- 
2.3.7

[PATCH v2 2/4] mmc: core: changes frequency to hs_max_dtr when selecting hs400es

[Shawn Lin]

Per JESD84-B51 P69, Host need to change frequency to <=52MHz
after setting HS_TIMING to 0x1, and host may changes frequency
to <= 200MHz after setting HS_TIMING to 0x3. That means the card
expects the clock rate to increase from the current used f_init
(which is less than 400KHz, but still being less than 52MHz) to
52MHz, otherwise we find some eMMC devices significantly report
failure when sending status.

Reported-by: Xiao Yao <xiaoyao@rock-chips.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

---

Changes in v2:
- improve the changelog

 drivers/mmc/core/mmc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f4ed5ac..39fc5b2 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1282,6 +1282,8 @@ static int mmc_select_hs400es(struct mmc_card *card)
 	if (err)
 		goto out_err;
 
+	mmc_set_clock(host, card->ext_csd.hs_max_dtr);
+
 	err = mmc_switch_status(card);
 	if (err)
 		goto out_err;
-- 
2.3.7

[PATCH v2 3/4] mmc: sdhci: Don't try to switch to unsupported voltage

[Shawn Lin]

From: Ziyuan Xu <xzy.xu@rock-chips.com>

Sdhci shouldn't switch to the unsupported voltage if claiming
that it can not support the requested voltage. Let's fix it.

Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

Changes in v2: None

 drivers/mmc/host/sdhci.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4805566..b1f1edd 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1845,7 +1845,8 @@ static int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
 
 	switch (ios->signal_voltage) {
 	case MMC_SIGNAL_VOLTAGE_330:
-		if (!(host->flags & SDHCI_SIGNALING_330))
+		if (!(host->flags & SDHCI_SIGNALING_330) ||
+		    !(host->caps & SDHCI_CAN_VDD_330))
 			return -EINVAL;
 		/* Set 1.8V Signal Enable in the Host Control2 register to 0 */
 		ctrl &= ~SDHCI_CTRL_VDD_180;
@@ -1872,7 +1873,8 @@ static int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
 
 		return -EAGAIN;
 	case MMC_SIGNAL_VOLTAGE_180:
-		if (!(host->flags & SDHCI_SIGNALING_180))
+		if (!(host->flags & SDHCI_SIGNALING_180) ||
+		    !(host->caps & SDHCI_CAN_VDD_180))
 			return -EINVAL;
 		if (!IS_ERR(mmc->supply.vqmmc)) {
 			ret = mmc_regulator_set_vqmmc(mmc, ios);
-- 
2.3.7

[PATCH v2 4/4] mmc: sdhci-of-arasan: add sdhci_arasan_voltage_switch for arasan,5.1

[Shawn Lin]

Per the vendor's requirement, we shouldn't do any setting for
1.8V Signaling Enable, otherwise the interaction/behaviour between
phy and controller will be undefined. Mostly it works fine if we do
that, but we still see failures. Anyway, let's fix it to meet the
vendor's requirement. The error log looks like:

 [   93.405085] mmc1: unexpected status 0x800900 after switch
 [   93.408474] mmc1: switch to bus width 1 failed
 [   93.408482] mmc1: mmc_select_hs200 failed, error -110
 [   93.408492] mmc1: error -110 during resume (card was removed?)
 [   93.408705] PM: resume of devices complete after 213.453 msecs

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

Changes in v2: None

 drivers/mmc/host/sdhci-of-arasan.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index da8e40a..1573a8d 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -265,6 +265,28 @@ void sdhci_arasan_reset(struct sdhci_host *host, u8 mask)
 	}
 }
 
+static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
+				       struct mmc_ios *ios)
+{
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_180:
+		/*
+		 * Plese don't switch to 1V8 as arasan,5.1 doesn't
+		 * actually refer to this setting to indicate the
+		 * signal voltage and the state machine will be broken
+		 * actually if we force to enable 1V8. That's something
+		 * like broken quirk but we could work around here.
+		 */
+		return 0;
+	case MMC_SIGNAL_VOLTAGE_330:
+	case MMC_SIGNAL_VOLTAGE_120:
+		/* We don't support 3V3 and 1V2 */
+		break;
+	}
+
+	return -EINVAL;
+}
+
 static struct sdhci_ops sdhci_arasan_ops = {
 	.set_clock = sdhci_arasan_set_clock,
 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
@@ -661,6 +683,8 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
 
 		host->mmc_host_ops.hs400_enhanced_strobe =
 					sdhci_arasan_hs400_enhanced_strobe;
+		host->mmc_host_ops.start_signal_voltage_switch =
+					sdhci_arasan_voltage_switch;
 	}
 
 	ret = sdhci_add_host(host);
-- 
2.3.7

Re: [PATCH v2 4/4] mmc: sdhci-of-arasan: add sdhci_arasan_voltage_switch for arasan,5.1

[Doug Anderson]

Hi,

On Thu, Sep 22, 2016 at 5:03 PM, Shawn Lin <shawn.lin@rock-chips.com> wrote:
> Per the vendor's requirement, we shouldn't do any setting for
> 1.8V Signaling Enable, otherwise the interaction/behaviour between
> phy and controller will be undefined. Mostly it works fine if we do
> that, but we still see failures. Anyway, let's fix it to meet the
> vendor's requirement. The error log looks like:
>
>  [   93.405085] mmc1: unexpected status 0x800900 after switch
>  [   93.408474] mmc1: switch to bus width 1 failed
>  [   93.408482] mmc1: mmc_select_hs200 failed, error -110
>  [   93.408492] mmc1: error -110 during resume (card was removed?)
>  [   93.408705] PM: resume of devices complete after 213.453 msecs
>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> ---
>
> Changes in v2: None
>
>  drivers/mmc/host/sdhci-of-arasan.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)

Seems OK to me.

Reviewed-by: Douglas Anderson <dianders@chromium.org>