Re: [PATCH v3 1/3] mmc: core: consistent handling of initial values

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On 6 November 2014 14:46, Johan Rudholm <johan.rudholm@xxxxxxxx> wrote:
> mmc_do_hw_reset(), mmc_power_up() and mmc_power_off() all set similar
> initial values for bus_mode, bus_width, chip_select and timing. Let's
> make this handling simpler and more consistent by sticking them
> together in a common function. This will introduce small changes in
> behavior in the following places:
>
> mmc_power_off():
>
>   For SPI hosts, explicitly set bus_mode = MMC_BUSMODE_PUSHPULL and
>   chip_select = MMC_CS_HIGH, before we left them as they were.
>
>   For non-SPI hosts, set bus_mode = MMC_BUSMODE_PUSHPULL instead of
>   MMC_BUSMODE_OPENDRAIN as before.
>
>   These two changes should not be a problem since the device will be
>   powered off anyway.
>
> mmc_do_hw_reset():
>
>   Always set bus_mode = MMC_BUSMODE_PUSHPULL, as required by SD/SDIO
>   cards. MMC cards require MMC_BUSMODE_OPENDRAIN, but this is taken
>   care of by mmc_init_card() and mmc_attach_mmc().
>
> Signed-off-by: Johan Rudholm <johanru@xxxxxxxx>

I decided to apply this one now for my next branch, thus we also get
some testing of it in linux-next.

If it turns out that it's causing issues, we need to come back to it.
For the rest of the patches I need some more time to review.

Thanks and kind regards
Uffe

> ---
>  drivers/mmc/core/core.c |   47 ++++++++++++++++++++++-------------------------
>  drivers/mmc/core/core.h |    1 +
>  2 files changed, 23 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index a32bea2..5bda29b 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1099,6 +1099,22 @@ void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
>         mmc_host_clk_release(host);
>  }
>
> +/*
> + * Set initial state after a power cycle or a hw_reset.
> + */
> +void mmc_set_initial_state(struct mmc_host *host)
> +{
> +       if (mmc_host_is_spi(host))
> +               host->ios.chip_select = MMC_CS_HIGH;
> +       else
> +               host->ios.chip_select = MMC_CS_DONTCARE;
> +       host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
> +       host->ios.bus_width = MMC_BUS_WIDTH_1;
> +       host->ios.timing = MMC_TIMING_LEGACY;
> +
> +       mmc_set_ios(host);
> +}
> +
>  /**
>   * mmc_vdd_to_ocrbitnum - Convert a voltage to the OCR bit number
>   * @vdd:       voltage (mV)
> @@ -1537,15 +1553,9 @@ void mmc_power_up(struct mmc_host *host, u32 ocr)
>         mmc_host_clk_hold(host);
>
>         host->ios.vdd = fls(ocr) - 1;
> -       if (mmc_host_is_spi(host))
> -               host->ios.chip_select = MMC_CS_HIGH;
> -       else
> -               host->ios.chip_select = MMC_CS_DONTCARE;
> -       host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
>         host->ios.power_mode = MMC_POWER_UP;
> -       host->ios.bus_width = MMC_BUS_WIDTH_1;
> -       host->ios.timing = MMC_TIMING_LEGACY;
> -       mmc_set_ios(host);
> +       /* Set initial state and call mmc_set_ios */
> +       mmc_set_initial_state(host);
>
>         /* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */
>         if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330) == 0)
> @@ -1585,14 +1595,9 @@ void mmc_power_off(struct mmc_host *host)
>         host->ios.clock = 0;
>         host->ios.vdd = 0;
>
> -       if (!mmc_host_is_spi(host)) {
> -               host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
> -               host->ios.chip_select = MMC_CS_DONTCARE;
> -       }
>         host->ios.power_mode = MMC_POWER_OFF;
> -       host->ios.bus_width = MMC_BUS_WIDTH_1;
> -       host->ios.timing = MMC_TIMING_LEGACY;
> -       mmc_set_ios(host);
> +       /* Set initial state and call mmc_set_ios */
> +       mmc_set_initial_state(host);
>
>         /*
>          * Some configurations, such as the 802.11 SDIO card in the OLPC
> @@ -2278,16 +2283,8 @@ static int mmc_do_hw_reset(struct mmc_host *host, int check)
>                 }
>         }
>
> -       if (mmc_host_is_spi(host)) {
> -               host->ios.chip_select = MMC_CS_HIGH;
> -               host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;
> -       } else {
> -               host->ios.chip_select = MMC_CS_DONTCARE;
> -               host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
> -       }
> -       host->ios.bus_width = MMC_BUS_WIDTH_1;
> -       host->ios.timing = MMC_TIMING_LEGACY;
> -       mmc_set_ios(host);
> +       /* Set initial state and call mmc_set_ios */
> +       mmc_set_initial_state(host);
>
>         mmc_host_clk_release(host);
>
> diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
> index 443a584..d76597c 100644
> --- a/drivers/mmc/core/core.h
> +++ b/drivers/mmc/core/core.h
> @@ -49,6 +49,7 @@ void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
>  void mmc_power_up(struct mmc_host *host, u32 ocr);
>  void mmc_power_off(struct mmc_host *host);
>  void mmc_power_cycle(struct mmc_host *host, u32 ocr);
> +void mmc_set_initial_state(struct mmc_host *host);
>
>  static inline void mmc_delay(unsigned int ms)
>  {
> --
> 1.7.2.5
>
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