This adds two new HS400 tuning operations: * hs400_downgrade * hs400_complete
These supplement the existing HS400 operation: * prepare_hs400_tuning This is motivated by a requirement of Renesas SDHI for the following: 1. Disabling SCC before selecting to HS if selection of HS400 has occurred. This can be done in an implementation of prepare_hs400_tuning_downgrade 2. Updating registers after switching to HS400 This can be done in an implementation of complete_hs400_tuning If hs400_downgrade or hs400_complete are not implemented then they are not called. Thus means there should be no affect for existing drivers as none implemt these ops. Signed-off-by: Simon Horman <[email protected]> --- v5 * Reworked as per feedback from Ulf Hansson - Call ops from mmc_hs400_to_hs200() and mmc_select_hs400() rather than mmc_retune() and mmc_select_timing(). This moves card code further away from core code and makes the patch somewhat tider. - Use shorter names for new ops. v4 * New patch --- drivers/mmc/core/mmc.c | 10 ++++++++++ include/linux/mmc/host.h | 7 +++++++ 2 files changed, 17 insertions(+) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 4466f5de54d4..63a52379e8ab 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1169,6 +1169,10 @@ static int mmc_select_hs400(struct mmc_card *card) /* Set host controller to HS timing */ mmc_set_timing(card->host, MMC_TIMING_MMC_HS); + /* Prepare host to downgrade to HS timing */ + if (host->ops->hs400_downgrade) + host->ops->hs400_downgrade(host); + /* Reduce frequency to HS frequency */ max_dtr = card->ext_csd.hs_max_dtr; mmc_set_clock(host, max_dtr); @@ -1209,6 +1213,9 @@ static int mmc_select_hs400(struct mmc_card *card) if (err) goto out_err; + if (host->ops->hs400_complete) + host->ops->hs400_complete(host); + return 0; out_err: @@ -1256,6 +1263,9 @@ int mmc_hs400_to_hs200(struct mmc_card *card) mmc_set_timing(host, MMC_TIMING_MMC_HS); + if (host->ops->hs400_downgrade) + host->ops->hs400_downgrade(host); + err = mmc_switch_status(card); if (err) goto out_err; diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 64300a48dcce..a39e2925c84c 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -146,6 +146,13 @@ struct mmc_host_ops { /* Prepare HS400 target operating frequency depending host driver */ int (*prepare_hs400_tuning)(struct mmc_host *host, struct mmc_ios *ios); + + /* Prepare for switching from HS400 to HS200 */ + void (*hs400_downgrade)(struct mmc_host *host); + + /* Complete selection of HS400 */ + void (*hs400_complete)(struct mmc_host *host); + /* Prepare enhanced strobe depending host driver */ void (*hs400_enhanced_strobe)(struct mmc_host *host, struct mmc_ios *ios); -- 2.11.0
