Re: [PATCH V16 12/23] mmc: sdhci-uhs2: add reset function function
From: Victor Shih
Date: Fri May 31 2024 - 06:32:33 EST
On Fri, May 24, 2024 at 3:23 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> On 22/05/24 14:08, Victor Shih wrote:
> > From: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
> >
> > Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >
> > Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> > Signed-off-by: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
> > ---
> >
> > Updates in V15:
> > - Refer the SD Host Controller Standard Specification Section 3.10
> > to add reset command data mechanism.
> >
> > Updates in V14:
> > - Since mmc_card_uhs2() is the same as sdhci_uhs2_mode(), so drop
> > sdhci_uhs2_mode() and use mmc_card_uhs2() instead of sdhci_uhs2_mode().
> >
> > Updates in V13:
> > - Use ios timing to stead MMC_UHS2_SUPPORT for indicate the UHS2 mode.
> >
> > Updates in V8:
> > - Adjust the position of matching brackets.
> >
> > Updates in V6:
> > - Remove unnecessary functions and simplify code.
> >
> > ---
> >
> > drivers/mmc/host/sdhci-uhs2.c | 57 +++++++++++++++++++++++++++++++++++
> > drivers/mmc/host/sdhci-uhs2.h | 1 +
> > drivers/mmc/host/sdhci.c | 3 +-
> > drivers/mmc/host/sdhci.h | 1 +
> > 4 files changed, 61 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > index 9cb0f1b2a37d..7652158ea151 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.c
> > +++ b/drivers/mmc/host/sdhci-uhs2.c
> > @@ -10,7 +10,9 @@
> > * Author: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> > */
> >
> > +#include <linux/delay.h>
> > #include <linux/module.h>
> > +#include <linux/iopoll.h>
> >
> > #include "sdhci.h"
> > #include "sdhci-uhs2.h"
> > @@ -21,6 +23,8 @@
> > #define SDHCI_UHS2_DUMP(f, x...) \
> > pr_err("%s: " DRIVER_NAME ": " f, mmc_hostname(host->mmc), ## x)
> >
> > +#define UHS2_RESET_TIMEOUT_100MS 100000
> > +
> > void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> > {
> > if (!(mmc_card_uhs2(host->mmc)))
> > @@ -49,6 +53,57 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> > }
> > EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >
> > +/*****************************************************************************\
> > + * *
> > + * Low level functions *
> > + * *
> > +\*****************************************************************************/
> > +
> > +/**
> > + * sdhci_uhs2_reset - invoke SW reset
> > + * @host: SDHCI host
> > + * @mask: Control mask
> > + *
> > + * Invoke SW reset, depending on a bit in @mask and wait for completion.
> > + */
> > +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
> > +{
> > + u32 val;
> > +
> > + sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
> > +
> > + if (mask & SDHCI_UHS2_SW_RESET_FULL)
> > + host->clock = 0;
> > +
> > + /* hw clears the bit when it's done */
> > + if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
> > + UHS2_RESET_TIMEOUT_100MS, true, host, SDHCI_UHS2_SW_RESET)) {
> > + pr_warn("%s: %s: Reset 0x%x never completed. %s: clean reset bit.\n", __func__,
> > + mmc_hostname(host->mmc), (int)mask, mmc_hostname(host->mmc));
> > + sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
> > + return;
> > + }
> > +}
> > +EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
> > +
> > +static void sdhci_uhs2_reset_cmd_data(struct mmc_host *mmc)
> > +{
> > + struct sdhci_host *host = mmc_priv(mmc);
> > +
> > + sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> > +
> > + if (host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_A ||
> > + host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> > + host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_B ||
> > + host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_B_HD) {
>
> Please use mmc_card_uhs2()
>
Hi, Adrian
I will update this in the v17 version.
Thanks, Victor Shih
> > + sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET_SD);
> > +
> > + sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
> > + sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
> > + sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK, SDHCI_UHS2_INT_ERROR_MASK);
> > + }
> > +}
> > +
> > /*****************************************************************************\
> > * *
> > * Driver init/exit *
> > @@ -57,6 +112,8 @@ EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >
> > static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
> > {
> > + host->mmc_host_ops.uhs2_reset_cmd_data = sdhci_uhs2_reset_cmd_data;
>
> As noted for patch 8, any host controller resets needed
> should be done before completing the request, so a call
> back function should not be needed.
>
Hi, Adrian
I want to confirm further, so can I call
sdhci_uhs2_reset_cmd_data() directly
in the mmc_wait_for_req_done()?
Am I understanding something wrong?
Thanks, Victor Shih
> > +
> > return 0;
> > }
> >
> > diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> > index 2bfe18d29bca..caaf9fba4975 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.h
> > +++ b/drivers/mmc/host/sdhci-uhs2.h
> > @@ -177,5 +177,6 @@
> > struct sdhci_host;
> >
> > void sdhci_uhs2_dump_regs(struct sdhci_host *host);
> > +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
> >
> > #endif /* __SDHCI_UHS2_H */
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 8fc3e001db74..f212da6dc2aa 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -236,7 +236,7 @@ void sdhci_reset(struct sdhci_host *host, u8 mask)
> > }
> > EXPORT_SYMBOL_GPL(sdhci_reset);
> >
> > -static bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
> > +bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
> > {
> > if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
> > struct mmc_host *mmc = host->mmc;
> > @@ -249,6 +249,7 @@ static bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
> >
> > return true;
> > }
> > +EXPORT_SYMBOL_GPL(sdhci_do_reset);
> >
> > static void sdhci_reset_for_all(struct sdhci_host *host)
> > {
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index 13703f1a3710..83d994c8d89e 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -845,6 +845,7 @@ void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq);
> > int sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq);
> > void sdhci_set_bus_width(struct sdhci_host *host, int width);
> > void sdhci_reset(struct sdhci_host *host, u8 mask);
> > +bool sdhci_do_reset(struct sdhci_host *host, u8 mask);
> > void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
> > int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
> > int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode);
>