From 1fb5c90b787b540546324478f3b1d921e20aff00 Mon Sep 17 00:00:00 2001 From: Haibo Chen Date: Mon, 26 Feb 2018 15:12:18 +0800 Subject: [PATCH] MLK-17621-2 mmc: add feature of setting slot index via devicetree alias Add feature of setting slot index via devicetree alias, to hard code the mmc/sd root device. The patch requires additional alias_id fix or it won't work. Note: minor device number keep independent with this device alias. Refer to the commit 35928d6c6a76 ("mmc: Allow setting slot index via devicetree alias"). Acked-by: Leonard Crestez Reviewed-by: Dong Aisheng Signed-off-by: Haibo Chen --- drivers/mmc/core/core.c | 38 ++++++++++++++++++++++++++++++++++++++ drivers/mmc/core/core.h | 2 ++ drivers/mmc/core/host.c | 12 ++++++++++-- drivers/of/base.c | 30 ++++++++++++++++++++++++++++++ include/linux/of.h | 6 ++++++ 5 files changed, 86 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index b1569049ea95..905211e86f95 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -58,6 +58,8 @@ static const unsigned freqs[] = { 400000, 300000, 200000, 100000 }; +static int __mmc_max_reserved_idx = -1; + /* * Enabling software CRCs on the data blocks can be a significant (30%) * performance cost, and for other reasons may not always be desired. @@ -2975,10 +2977,46 @@ void mmc_init_context_info(struct mmc_host *host) init_waitqueue_head(&host->context_info.wait); } +/* + * mmc_first_nonreserved_index() - get the first index that + * is not reserved + */ +int mmc_first_nonreserved_index(void) +{ + return __mmc_max_reserved_idx + 1; +} +EXPORT_SYMBOL(mmc_first_nonreserved_index); + +/* + * mmc_get_reserved_index() - get the index reserved for this host + * Return: The index reserved for this host or negative error value + * if no index is reserved for this host + */ +int mmc_get_reserved_index(struct mmc_host *host) +{ + return of_alias_get_id(host->parent->of_node, "mmc"); +} +EXPORT_SYMBOL(mmc_get_reserved_index); + +static void mmc_of_reserve_idx(void) +{ + int max; + + max = of_alias_max_index("mmc"); + if (max < 0) + return; + + __mmc_max_reserved_idx = max; + pr_debug("MMC: reserving %d slots for of aliases\n", + __mmc_max_reserved_idx + 1); +} + static int __init mmc_init(void) { int ret; + mmc_of_reserve_idx(); + ret = mmc_register_bus(); if (ret) return ret; diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h index df4809516f45..cfe00be3e652 100644 --- a/drivers/mmc/core/core.h +++ b/drivers/mmc/core/core.h @@ -82,6 +82,8 @@ int mmc_attach_mmc(struct mmc_host *host); int mmc_attach_sd(struct mmc_host *host); int mmc_attach_sdio(struct mmc_host *host); +int mmc_first_nonreserved_index(void); +int mmc_get_reserved_index(struct mmc_host *host); /* Module parameters */ extern bool use_spi_crc; diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index 6830bd2d5d26..4c680453e0fb 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -348,6 +348,7 @@ EXPORT_SYMBOL(mmc_of_parse); struct mmc_host *mmc_alloc_host(int extra, struct device *dev) { int err; + int alias_id; struct mmc_host *host; host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL); @@ -356,8 +357,16 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev) /* scanning will be enabled when we're ready */ host->rescan_disable = 1; + host->parent = dev; - err = ida_simple_get(&mmc_host_ida, 0, 0, GFP_KERNEL); + alias_id = mmc_get_reserved_index(host); + if (alias_id >= 0) + err = ida_simple_get(&mmc_host_ida, alias_id, + alias_id + 1, GFP_KERNEL); + else + err = ida_simple_get(&mmc_host_ida, + mmc_first_nonreserved_index(), + 0, GFP_KERNEL); if (err < 0) { kfree(host); return NULL; @@ -367,7 +376,6 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev) dev_set_name(&host->class_dev, "mmc%d", host->index); - host->parent = dev; host->class_dev.parent = dev; host->class_dev.class = &mmc_host_class; device_initialize(&host->class_dev); diff --git a/drivers/of/base.c b/drivers/of/base.c index 63897531cd75..9b4b7ee291a2 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1641,6 +1641,36 @@ static void of_alias_add(struct alias_prop *ap, struct device_node *np, ap->alias, ap->stem, ap->id, np); } +/* + * of_alias_max_index() - get the maximum index for a given alias stem + * @stem: The alias stem for which the maximum index is searched for + * + * Given an alias stem (the alias without the number) this function + * returns the maximum number for which an alias exists. + * + * Return: The maximum existing alias index or -ENODEV if no alias + * exists for this stem. + */ +int of_alias_max_index(const char *stem) +{ + struct alias_prop *app; + int max = -ENODEV; + + mutex_lock(&of_mutex); + + list_for_each_entry(app, &aliases_lookup, link) { + if (strcmp(app->stem, stem)) + continue; + if (app->id > max) + max = app->id; + } + + mutex_unlock(&of_mutex); + + return max; +} +EXPORT_SYMBOL_GPL(of_alias_max_index); + /** * of_alias_scan - Scan all properties of the 'aliases' node * diff --git a/include/linux/of.h b/include/linux/of.h index b240ed69dc96..9719ebe26a30 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -382,6 +382,7 @@ extern int of_phandle_iterator_args(struct of_phandle_iterator *it, extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)); extern int of_alias_get_id(struct device_node *np, const char *stem); extern int of_alias_get_highest_id(const char *stem); +extern int of_alias_max_index(const char *stem); extern int of_machine_is_compatible(const char *compat); @@ -818,6 +819,11 @@ static inline int of_alias_get_highest_id(const char *stem) return -ENOSYS; } +static inline int of_alias_max_index(const char *stem) +{ + return -ENODEV; +} + static inline int of_machine_is_compatible(const char *compat) { return 0;