diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.14.71/5729-mmc-core-more-fine-grained-hooks-for-HS400-tuning.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.14.71/5729-mmc-core-more-fine-grained-hooks-for-HS400-tuning.patch | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.14.71/5729-mmc-core-more-fine-grained-hooks-for-HS400-tuning.patch b/common/recipes-kernel/linux/linux-yocto-4.14.71/5729-mmc-core-more-fine-grained-hooks-for-HS400-tuning.patch new file mode 100644 index 00000000..4bf16a6d --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.14.71/5729-mmc-core-more-fine-grained-hooks-for-HS400-tuning.patch @@ -0,0 +1,89 @@ +From d6e5823c602272567f80cffdcafbf715192d43fc Mon Sep 17 00:00:00 2001 +From: Chaudhary Amit Kumar <chaudharyamit.kumar@amd.com> +Date: Tue, 12 Feb 2019 19:07:08 +0530 +Subject: [PATCH 5729/5758] 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> +Signed-off-by: Sudheesh Mavila <sudheesh.mavila@amd.com> + +Signed-off-by: Chaudhary Amit Kumar <chaudharyamit.kumar@amd.com> +--- + drivers/mmc/core/mmc.c | 11 +++++++++++ + include/linux/mmc/host.h | 7 +++++++ + 2 files changed, 18 insertions(+) + +diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c +index c768d08..cd3604d 100755 +--- a/drivers/mmc/core/mmc.c ++++ b/drivers/mmc/core/mmc.c +@@ -1165,6 +1165,11 @@ static int mmc_select_hs400(struct mmc_card *card) + if (!host->ops->set_hs400_dll) { + /* 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); +@@ -1257,6 +1262,9 @@ 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; +@@ -1394,6 +1402,9 @@ static int mmc_select_hs400es(struct mmc_card *card) + if (err) + goto out_err; + ++ if (host->ops->hs400_complete) ++ host->ops->hs400_complete(host); ++ + return 0; + + out_err: +diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h +index b7d5611..ba4af38 100755 +--- a/include/linux/mmc/host.h ++++ b/include/linux/mmc/host.h +@@ -145,6 +145,13 @@ 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); +-- +2.7.4 + |