Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:59315 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758632Ab0GURfT (ORCPT ); Wed, 21 Jul 2010 13:35:19 -0400 From: Ohad Ben-Cohen To: , , Cc: , , Chikkature Rajashekar Madhusudhan , Luciano Coelho , , San Mehat , Roger Quadros , Tony Lindgren , Nicolas Pitre , Pandita Vikram , Kalle Valo , Ohad Ben-Cohen Subject: [PATCH v2 16/20] mmc: introduce API to control the card's power Date: Wed, 21 Jul 2010 20:33:50 +0300 Message-Id: <1279733634-21974-17-git-send-email-ohad@wizery.com> In-Reply-To: <1279733634-21974-1-git-send-email-ohad@wizery.com> References: <1279733634-21974-1-git-send-email-ohad@wizery.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Introduce the sdio_claim_power/sdio_release_power API (with correspoding mmc_claim_power/mmc_release_power) that controls the power of the card. A reference count scheme is employed, to allow SDIO function voting. Signed-off-by: Ohad Ben-Cohen --- drivers/mmc/core/bus.c | 3 ++ drivers/mmc/core/core.c | 50 +++++++++++++++++++++++++++++++++++++++++ drivers/mmc/core/sdio.c | 5 ++++ drivers/mmc/core/sdio_io.c | 50 +++++++++++++++++++++++++++++++++++++++++ include/linux/mmc/card.h | 2 + include/linux/mmc/host.h | 2 + include/linux/mmc/sdio_func.h | 3 ++ 7 files changed, 115 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c index 49d9dca..33151d5 100644 --- a/drivers/mmc/core/bus.c +++ b/drivers/mmc/core/bus.c @@ -17,6 +17,7 @@ #include #include +#include #include "core.h" #include "sdio_cis.h" @@ -207,6 +208,8 @@ struct mmc_card *mmc_alloc_card(struct mmc_host *host, struct device_type *type) card->host = host; + atomic_set(&card->power_claims, 0); + device_initialize(&card->dev); card->dev.parent = mmc_classdev(host); diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 569e94d..ca5e3bf 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1334,6 +1334,56 @@ EXPORT_SYMBOL(mmc_resume_host); #endif +/** + * mmc_release_power - remove power from the card + * @host: mmc host + */ +int mmc_release_power(struct mmc_host *host) +{ + int err = 0; + + mmc_bus_get(host); + if (host->bus_ops && !host->bus_dead) { + if (host->bus_ops->suspend) + err = host->bus_ops->suspend(host); + /* it's ok not to have a suspend handler */ + err = err == -ENOSYS ? 0 : err; + } + mmc_bus_put(host); + + if (!err) + mmc_power_off(host); + + return err; +} +EXPORT_SYMBOL_GPL(mmc_release_power); + +/* + * mmc_claim_power - power up card + * @host: mmc host + */ +int mmc_claim_power(struct mmc_host *host) +{ + int err = 0; + + mmc_bus_get(host); + + mmc_power_up(host); + mmc_select_voltage(host, host->ocr); + + BUG_ON(!host->bus_ops->resume); + err = host->bus_ops->resume(host); + if (err) { + printk(KERN_WARNING "%s: error %d during resume " + "(card was removed?)\n", + mmc_hostname(host), err); + } + mmc_bus_put(host); + + return err; +} +EXPORT_SYMBOL_GPL(mmc_claim_power); + static int __init mmc_init(void) { int ret; diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 37739f5..79e6fa1 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "core.h" #include "bus.h" @@ -72,6 +73,10 @@ static int sdio_init_func(struct mmc_card *card, unsigned int fn) card->sdio_func[fn - 1] = func; + /* For each SDIO function initialized, increase the power claim + * reference count of the card */ + atomic_inc(&card->power_claims); + return 0; fail: diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c index 0f687cd..28ebc16 100644 --- a/drivers/mmc/core/sdio_io.c +++ b/drivers/mmc/core/sdio_io.c @@ -17,6 +17,56 @@ #include "sdio_ops.h" /** + * sdio_release_power - allow to release power of a certain SDIO function + * @func: SDIO function that is accessed + * + * Indicate to the core SDIO layer that we're not requiring that the + * function remain powered. If all functions for the card are in the + * same "no power" state, then the host controller can remove power from + * the card. Note: the function driver must preserve hardware states if + * necessary. + */ +int sdio_release_power(struct sdio_func *func) +{ + int ret = 0; + BUG_ON(!func); + BUG_ON(!func->card); + + if (atomic_dec_and_test(&func->card->power_claims)) + ret = mmc_release_power(func->card->host); + + return ret; +} +EXPORT_SYMBOL_GPL(sdio_release_power); + +/* + * sdio_claim_power - request power for a certain SDIO function + * @func: SDIO function that is accessed + * + * Indicate to the core SDIO layer that we want power back for this + * SDIO function. The power may or may not actually have been removed + * since last call to sdio_release_power(), so the function driver must + * not assume any preserved state at the hardware level and re-perform + * all the necessary hardware config. This function returns 0 when + * power is actually restored, or some error code if this cannot be + * achieved. One error reason might be that the card is no longer + * available on the bus (was removed while powered down and card + * detection didn't trigger yet). + */ +int sdio_claim_power(struct sdio_func *func) +{ + int ret = 0; + BUG_ON(!func); + BUG_ON(!func->card); + + if (atomic_inc_return(&func->card->power_claims) == 1) + ret = mmc_claim_power(func->card->host); + + return ret; +} +EXPORT_SYMBOL_GPL(sdio_claim_power); + +/** * sdio_claim_host - exclusively claim a bus for a certain SDIO function * @func: SDIO function that will be accessed * diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index d02d2c6..4073b43 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -11,6 +11,7 @@ #define LINUX_MMC_CARD_H #include +#include struct mmc_cid { unsigned int manfid; @@ -120,6 +121,7 @@ struct mmc_card { struct sdio_func_tuple *tuples; /* unknown common tuples */ struct dentry *debugfs_root; + atomic_t power_claims; /* ref count of power requests */ }; #define mmc_card_mmc(c) ((c)->type == MMC_TYPE_MMC) diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 80db597..3675d58 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -234,6 +234,8 @@ static inline void *mmc_priv(struct mmc_host *host) extern int mmc_suspend_host(struct mmc_host *); extern int mmc_resume_host(struct mmc_host *); +extern int mmc_release_power(struct mmc_host *); +extern int mmc_claim_power(struct mmc_host *); extern void mmc_power_save_host(struct mmc_host *host); extern void mmc_power_restore_host(struct mmc_host *host); diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h index 31baaf8..e77b676 100644 --- a/include/linux/mmc/sdio_func.h +++ b/include/linux/mmc/sdio_func.h @@ -116,6 +116,9 @@ extern void sdio_unregister_driver(struct sdio_driver *); /* * SDIO I/O operations */ +int sdio_claim_power(struct sdio_func *func); +int sdio_release_power(struct sdio_func *func); + extern void sdio_claim_host(struct sdio_func *func); extern void sdio_release_host(struct sdio_func *func); -- 1.7.0.4