Re: [PATCH v2] mmc: sdhci-xenon: add set_power callback

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On 2017/8/29 2:45, Zhoujie Wu wrote:
Hi Gregory,

On 08/28/2017 08:54 AM, Gregory CLEMENT wrote:
Hi,
  On lun., août 28 2017, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:

On 21/08/17 21:02, Zhoujie Wu wrote:
Xenon sdh controller requests proper SD bus voltage select
bits programmed even with vmmc power supply. Any reserved
value(100b-000b) programmed in this field will lead to controller
ignore SD bus power bit and keep its value at zero.
Add set_power callback to handle this.

Signed-off-by: Zhoujie Wu <zjwu@xxxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
I tested this patch on the Armada 3720 DB board. And thanks to this patch
and by adding a vmmc regulator in the device tree I did not have anymore
the issue UHS card not detected on warm reset.

Tested-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>

Actually for me this should be a fix. Indeed if I try to use a vmmc
regulator without this patch then the SD card does not work at all I
only have the following messages:

"mmc1: Timeout waiting for hardware cmd interrupt."
This patch with sd vmmc power supply(must be claimed as AON, or card detection can't work)enabled can solve the issue for warm reset. This patch is must for xenon controller once vmmc power supply enabled, since the HW will ignore any reserved value for sd bus voltage select field and ignore the pwr_en in this case. But recently we met another issue after resume, it is similar as warm reset. When resume back, SD card(UHS) is re-initialized and it is recognized as HS again. It needs power-cycle before initialization to solve the resume issue. But vmmc is claimed as AON, it won't be shut

This is a expected behaviour from the spec's POV. So you need a high
level solution to solve it for all hosts. I just quickly cook a patch[1]
for test, maybe it doesn't work at all but I guess it helps.:)

[1]: https://patchwork.kernel.org/patch/9926715/

down in standby, so vmmc and this patch won't solve resume issue. I have no better idea to solve both warm reset and resume issue, I added a dedicated pwrseq for a3700 sd card, it will do power cycle during pre and post pwrseq, but keep power when power off the card.
Do you have any other better suggestion?

Thanks,

Gregory


---
Updated according to Jisheng Zhang's comment.
  drivers/mmc/host/sdhci-xenon.c | 19 +++++++++++++++++++
  1 file changed, 19 insertions(+)

diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
index edd4d915..a4be2fd 100644
--- a/drivers/mmc/host/sdhci-xenon.c
+++ b/drivers/mmc/host/sdhci-xenon.c
@@ -210,8 +210,27 @@ static void xenon_set_uhs_signaling(struct sdhci_host *host,
      sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
  }
+static void xenon_set_power(struct sdhci_host *host, unsigned char mode,
+        unsigned short vdd)
+{
+    struct mmc_host *mmc = host->mmc;
+    u8 pwr = host->pwr;
+
+    sdhci_set_power_noreg(host, mode, vdd);
+
+    if (host->pwr == pwr)
+        return;
+
+    if (host->pwr == 0)
+        vdd = 0;
+
+    if (!IS_ERR(mmc->supply.vmmc))
+        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
+}
+
  static const struct sdhci_ops sdhci_xenon_ops = {
      .set_clock        = sdhci_set_clock,
+    .set_power        = xenon_set_power,
      .set_bus_width        = sdhci_set_bus_width,
      .reset            = xenon_reset,
      .set_uhs_signaling    = xenon_set_uhs_signaling,


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