Re: [PATCH v2 3/4] mmc: core: turn hw_reset into a bus_ops

Adrian Hunter
2014-11-05T12:11:59Z

On 04/11/14 17:07, Johan Rudholm wrote:
> Move the (e)MMC specific hw_reset code from core.c into mmc.c and call
> it from the new bus_ops member hw_reset. This also lets us add code
> for reseting SD cards as well.
>
> Signed-off-by: Johan Rudholm <johanru@axis.com>
> ---
> drivers/mmc/card/mmc_test.c | 3 --
> drivers/mmc/core/core.c | 48 ++++++++----------------------------------
> drivers/mmc/core/core.h | 4 +++
> drivers/mmc/core/mmc.c | 37 +++++++++++++++++++++++++++++++++
> include/linux/mmc/core.h | 1 -
> 5 files changed, 50 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
> index 0c0fc52..2cd3385 100644
> --- a/drivers/mmc/card/mmc_test.c
> +++ b/drivers/mmc/card/mmc_test.c
> @@ -2349,9 +2349,6 @@ static int mmc_test_hw_reset(struct mmc_test_card *test)
> if (err != -EOPNOTSUPP)
> return err;
>
> - if (!mmc_can_reset(card))
> - return RESULT_UNSUP_CARD;
> -

I would like to retain the ability for mmc_test to distinguish
RESULT_UNSUP_CARD from RESULT_UNSUP_HOST

> return RESULT_UNSUP_HOST;
> }
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 2c39d26..b35f205 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -2239,64 +2239,34 @@ static void mmc_hw_reset_for_init(struct mmc_host *host)
> mmc_host_clk_release(host);
> }
>
> -int mmc_can_reset(struct mmc_card *card)
> -{
> - u8 rst_n_function;
> -
> - if (!mmc_card_mmc(card))
> - return 0;
> - rst_n_function = card->ext_csd.rst_n_function;
> - if ((rst_n_function & EXT_CSD_RST_N_EN_MASK) != EXT_CSD_RST_N_ENABLED)
> - return 0;
> - return 1;
> -}
> -EXPORT_SYMBOL(mmc_can_reset);
> -
> +/* Reset card in a bus-specific way */
> static int mmc_do_hw_reset(struct mmc_host *host, int check)
> {
> - struct mmc_card *card = host->card;
> -
> - if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)
> - return -EOPNOTSUPP;
> + int ret;
>
> - if (!card)
> + if (!host->card)
> return -EINVAL;
>
> - if (!mmc_can_reset(card))
> + if (!host->bus_ops || !host->bus_ops->hw_reset ||
> + host->bus_ops->hw_reset(host, MMC_HW_RESET_TEST))
> return -EOPNOTSUPP;
>
> - mmc_host_clk_hold(host);
> - mmc_set_clock(host, host->f_init);
> -
> - host->ops->hw_reset(host);
> -
> - /* If the reset has happened, then a status command will fail */
> - if (check) {
> - u32 status;
> -
> - if (!mmc_send_status(card, &status)) {
> - mmc_host_clk_release(host);
> - return -ENOSYS;
> - }
> - }
> -
> - /* Set initial state and call mmc_set_ios */
> - mmc_set_initial_state(host);
> + ret = host->bus_ops->hw_reset(host, check);
>
> - mmc_host_clk_release(host);
> + pr_warn("%s: tried to reset card (%d)\n", mmc_hostname(host), ret);
>
> return host->bus_ops->power_restore(host);
> }
>
> int mmc_hw_reset(struct mmc_host *host)
> {
> - return mmc_do_hw_reset(host, 0);
> + return mmc_do_hw_reset(host, MMC_HW_RESET_RESET);
> }
> EXPORT_SYMBOL(mmc_hw_reset);
>
> int mmc_hw_reset_check(struct mmc_host *host)
> {
> - return mmc_do_hw_reset(host, 1);
> + return mmc_do_hw_reset(host, MMC_HW_RESET_CHECK);
> }
> EXPORT_SYMBOL(mmc_hw_reset_check);
>
> diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
> index d76597c..918bbe8 100644
> --- a/drivers/mmc/core/core.h
> +++ b/drivers/mmc/core/core.h
> @@ -27,6 +27,10 @@ struct mmc_bus_ops {
> int (*power_restore)(struct mmc_host *);
> int (*alive)(struct mmc_host *);
> int (*shutdown)(struct mmc_host *);
> + int (*hw_reset)(struct mmc_host *, int);
> +#define MMC_HW_RESET_RESET 0
> +#define MMC_HW_RESET_TEST 1
> +#define MMC_HW_RESET_CHECK 2
> };
>
> void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 793c6f7..55e1a97 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1773,6 +1773,42 @@ static int mmc_power_restore(struct mmc_host *host)
> return ret;
> }
>
> +static int mmc_mmc_hw_reset(struct mmc_host *host, int test)
> +{
> + struct mmc_card *card = host->card;
> + u8 rst_n_function;
> +
> + if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)
> + return -EOPNOTSUPP;
> +
> + rst_n_function = card->ext_csd.rst_n_function;
> + if ((rst_n_function & EXT_CSD_RST_N_EN_MASK) != EXT_CSD_RST_N_ENABLED)
> + return -EOPNOTSUPP;
> +
> + if (test == MMC_HW_RESET_TEST)
> + return 0;
> +
> + mmc_host_clk_hold(host);
> + mmc_set_clock(host, host->f_init);
> +
> + host->ops->hw_reset(host);
> +
> + if (test == MMC_HW_RESET_CHECK) {
> + u32 status;
> +
> + if (!mmc_send_status(card, &status)) {
> + mmc_host_clk_release(host);
> + return -ENOSYS;
> + }
> + }
> +
> + mmc_set_initial_state(host);
> +
> + mmc_host_clk_release(host);
> +
> + return 0;
> +}
> +
> static const struct mmc_bus_ops mmc_ops = {
> .remove = mmc_remove,
> .detect = mmc_detect,
> @@ -1783,6 +1819,7 @@ static const struct mmc_bus_ops mmc_ops = {
> .power_restore = mmc_power_restore,
> .alive = mmc_alive,
> .shutdown = mmc_shutdown,
> + .hw_reset = mmc_mmc_hw_reset,
> };
>
> /*
> diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
> index f206e29..d7e02a7 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -182,7 +182,6 @@ extern int mmc_set_blockcount(struct mmc_card *card, unsigned int blockcount,
> bool is_rel_write);
> extern int mmc_hw_reset(struct mmc_host *host);
> extern int mmc_hw_reset_check(struct mmc_host *host);
> -extern int mmc_can_reset(struct mmc_card *card);
>
> extern void mmc_set_data_timeout(struct mmc_data *, const struct mmc_card *);
> extern unsigned int mmc_align_data_size(struct mmc_card *, unsigned int);
>