MMC-4.5 Power OFF Notify Rework
This is a rework of the existing POWER OFF NOTIFY patch. The current problem
with the patch comes from the ambiguity on the usage of POWER OFF NOTIFY
together with SLEEP and misunderstanding on the usage of MMC_POWER_OFF
power_mode from mmc_set_ios in different host controller drivers.
This new patch works around this problem by adding a new host CAP,
MMC_CAP2_POWER_OFF_VCCQ_DURING_SUSPEND, which when set sends a
POWER OFF NOTIFY from mmc_suspend instead of SLEEP. It is expected that host
controller drivers will set this CAP, if they switch off both Vcc and Vccq
from MMC_POWER_OFF condition within mmc_set_ios. However, note that there
is no harm in sending MMC_POWER_NOTIFY even if Vccq is not switched off.
This patch also sends POWER OFF NOTIFY from power management routines (e.g.
mmc_power_save_host, mmc_pm_notify/PM_SUSPEND_PREPARE, mmc_stop_host), which
does reinitialization of the eMMC on the return path of the power management
routines (e.g. mmc_power_restore_host, mmc_pm_notify/PM_POST_RESTORE,
mmc_start_host).
This patch sets POWER_OFF_NOTIFICATION to POWER_OFF_SHORT if it is sent from
the suspend sequence. If it is sent from shutdown sequence then it is set to
POWER_OFF_LONG.
Earlier implementation of PowerOff Notify as a core function is replaced as
a device's bus operation.
Signed-off-by: Saugata Das <saugata.das@linaro.org>
Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
changes in v5:
modified the the handling of return value in mmc_poweroff_notify.
changes in v4:
As suggested in review,
- Moved mmc_can_poweroff_notify to core.c
- Moved mmc_claim_host, mmc_release_host outside mmc_poweroff_notify
- Added check for wrong initialization for poweroff_notify_type
- mmc_poweroff_notify is modified to take as 2nd parameter
changes in v3:
This version addresses the review comments given by Subhash and Ulf
changes in v2:
This version addresses the changes suggested by Ulf
[smuckle@codeaurora.org: resolve minor merge conflicts]
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 1adfbe7..3f6d994 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -265,11 +265,10 @@
#define MMC_QUIRK_LONG_READ_TIME (1<<9) /* Data read time > CSD says */
/* byte mode */
#define MMC_QUIRK_INAND_DATA_TIMEOUT (1<<8) /* For incorrect data timeout */
- unsigned int poweroff_notify_state; /* eMMC4.5 notify feature */
+ unsigned int poweroff_notify_state; /* eMMC4.5 notify
+ feature */
#define MMC_NO_POWER_NOTIFICATION 0
#define MMC_POWERED_ON 1
-#define MMC_POWEROFF_SHORT 2
-#define MMC_POWEROFF_LONG 3
unsigned int erase_size; /* erase size in sectors */
unsigned int erase_shift; /* if erase unit is power 2 */