linux/drivers
Rajendra Nayak 1f84b71b3f mmc: omap_hsmmc: Avoid a regulator voltage change with dt
When booting with Device tree, the omap_hsmmc driver does not
program the pbias cell (inside OMAP control module) during
a regulator voltage change.

In case of non-dt boot, this is handled using callbacks
from within platform_data and implemented in machine code.
To be able to do this with device tree, without invoking
any machine code, a OMAP control module driver is needed
which is yet missing.

The pbias cell is used to provide a 1.8v or 3.0v reference
to the mmc/sd/sdio1 interface supporting both 1.8v and 3.0v
voltages.

Until a OMAP control module driver is available to handle this,
when booting with a device tree blob, never change the regulator
voltage which might then require a pbias cell re-program.
There are 2 instances where in the mmc regulator voltage can be
changed.
-1- when the regulator is turned OFF.
-2- when attempting a switch to 1.8v from 3.0v for dual volt cards

This patch avoids a voltage change in both cases when booting from
device tree, and hence compromises on power savings.
Once the OMAP control module driver is available and hsmmc driver
is modified to then do pbias programming even when booting
with device tree, these limitaions can be removed to achieve better
power savings.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Tested-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-03-27 12:20:10 -04:00
..
accessibility vt:tackle kbd_table 2012-03-08 10:50:35 -08:00
acpi
amba
ata ata: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:16 +08:00
atm eni: fix driver remove function and driver probe error path. 2012-03-16 23:13:20 -07:00
auxdisplay
base Core device tree changes for Linux v3.4 2012-03-21 10:30:03 -07:00
bcma bcma: silence PMU warning for BCM4331 2012-03-07 13:56:37 -05:00
block Merge branch 'kmap_atomic' of git://github.com/congwang/linux 2012-03-21 09:40:26 -07:00
bluetooth Bluetooth: Adding USB device 13d3:3375 as an Atheros AR3012. 2012-03-08 02:16:24 -03:00
cdrom
char Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2012-03-21 13:25:04 -07:00
clk
clocksource Power management updates for 3.4 2012-03-21 10:15:51 -07:00
connector
cpufreq
cpuidle Merge branch 'perf/urgent' into perf/core 2012-03-05 09:20:08 +01:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2012-03-21 13:20:43 -07:00
dca
devfreq PM / devfreq: add relation of recommended frequency. 2012-03-17 21:51:34 +01:00
dio
dma Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-03-20 21:12:50 -07:00
edac edac: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:17 +08:00
eisa
firewire
firmware
gpio
gpu Merge branch 'kmap_atomic' of git://github.com/congwang/linux 2012-03-21 09:40:26 -07:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2012-03-20 21:11:42 -07:00
hv Tools: hv: Support enumeration from all the pools 2012-03-16 13:36:04 -07:00
hwmon hwmon changes for v3.4 2012-03-21 10:37:25 -07:00
hwspinlock
i2c i2c-algo-bit: Fix spurious SCL timeouts under heavy load 2012-03-15 18:11:05 +01:00
ide ide: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:17 +08:00
idle
ieee802154
infiniband InfiniBand/RDMA changes for the 3.4 merge window. Nothing big really 2012-03-21 10:33:42 -07:00
input driver core merge for 3.4-rc1 2012-03-20 11:16:20 -07:00
iommu Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-03-20 21:12:50 -07:00
isdn Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2012-03-20 21:04:47 -07:00
leds
lguest
macintosh Core device tree changes for Linux v3.4 2012-03-21 10:30:03 -07:00
mca
md Merge branch 'kmap_atomic' of git://github.com/congwang/linux 2012-03-21 09:40:26 -07:00
media Merge branch 'kmap_atomic' of git://github.com/congwang/linux 2012-03-21 09:40:26 -07:00
memstick memstick: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:19 +08:00
message
mfd regulator: Updates for 3.4 2012-03-21 10:34:56 -07:00
misc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-03-21 13:36:41 -07:00
mmc mmc: omap_hsmmc: Avoid a regulator voltage change with dt 2012-03-27 12:20:10 -04:00
mtd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-03-20 21:12:50 -07:00
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-03-21 13:36:41 -07:00
nfc NFC: Remove the rf mode parameter from the DEP link up routine 2012-03-06 15:16:23 -05:00
nubus
of Core device tree changes for Linux v3.4 2012-03-21 10:30:03 -07:00
oprofile tidy up after d_make_root() conversion 2012-03-20 21:29:37 -04:00
parisc
parport
pci Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2012-03-20 21:04:47 -07:00
pcmcia Merge 3.3-rc6 into driver-core-next 2012-03-09 12:35:53 -08:00
pinctrl
platform Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-03-20 21:12:50 -07:00
pnp
power Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-03-20 21:12:50 -07:00
pps pps: class_create() returns an ERR_PTR, not NULL 2012-03-05 15:49:43 -08:00
ps3
ptp phc: Update author's email address. 2012-03-17 01:41:43 -07:00
rapidio rapidio/tsi721: fix bug in register offset definitions 2012-03-15 17:03:03 -07:00
regulator regulator: Updates for 3.4 2012-03-21 10:34:56 -07:00
rtc Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-20 10:32:09 -07:00
s390 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2012-03-20 21:04:47 -07:00
sbus
scsi Merge branch 'kmap_atomic' of git://github.com/congwang/linux 2012-03-21 09:40:26 -07:00
sfi
sh
sn
spi SPI changes for v3.4. 2012-03-21 10:32:00 -07:00
ssb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2012-03-20 21:04:47 -07:00
staging Merge branch 'kmap_atomic' of git://github.com/congwang/linux 2012-03-21 09:40:26 -07:00
target Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2012-03-21 13:25:04 -07:00
tc
thermal
tty Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-03-20 21:12:50 -07:00
uio
usb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-03-21 13:36:41 -07:00
uwb
vhost vhost: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:21 +08:00
video drivers/video/backlight/s6e63m0.c: fix corruption storing gamma mode 2012-03-15 17:03:04 -07:00
virt
virtio virtio: balloon: leak / fill balloon across S4 2012-03-01 09:28:41 +10:30
vlynq
w1 DS2781 Maxim Stand-Alone Fuel Gauge battery and w1 slave drivers 2012-03-08 11:15:33 -08:00
watchdog watchdog: fix GETTIMEOUT ioctl in booke_wdt 2012-02-29 09:46:13 +01:00
xen Merge branch 'pm-sleep' 2012-03-04 23:11:14 +01:00
zorro
Kconfig
Makefile