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| author | Simon Horman <horms+renesas@verge.net.au> | 2018-06-18 14:57:49 +0200 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2018-07-16 11:21:45 +0200 |
| commit | ba6c7ac3a2f421635ae4446269526359d8bff721 (patch) | |
| tree | 995857a0951837faed4683e20162dcae1524b66c | |
| parent | ecf7c7c5855aca18ddde534d7bfff111ce0cb26f (diff) | |
| download | linux-ba6c7ac3a2f421635ae4446269526359d8bff721.tar.gz linux-ba6c7ac3a2f421635ae4446269526359d8bff721.tar.bz2 linux-ba6c7ac3a2f421635ae4446269526359d8bff721.zip | |
mmc: core: more fine-grained hooks for HS400 tuning
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 <horms+renesas@verge.net.au>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
| -rw-r--r-- | drivers/mmc/core/mmc.c | 10 | ||||
| -rw-r--r-- | include/linux/mmc/host.h | 7 |
2 files changed, 17 insertions, 0 deletions
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); |