From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [RESEND PATCH v2 4/4] mmc: sdhci-of-arasan: add sdhci_arasan_voltage_switch for arasan,5.1 Date: Wed, 28 Sep 2016 11:20:08 +0300 Message-ID: References: <1474589577-11193-1-git-send-email-shawn.lin@rock-chips.com> <1474589577-11193-4-git-send-email-shawn.lin@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1474589577-11193-4-git-send-email-shawn.lin@rock-chips.com> Sender: linux-mmc-owner@vger.kernel.org To: Shawn Lin , Ulf Hansson Cc: Jaehoon Chung , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org List-Id: linux-rockchip.vger.kernel.org On 23/09/16 03:12, Shawn Lin 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 Acked-by: Adrian Hunter > --- > > 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); >