eukrea_mbimxsd51-baseboard.c and mach-cpuimx51sd.c can be replaced with their
devicetree equivalents: imx51-eukrea-mbimxsd51-baseboard.dts and
imx51-eukrea-cpuimx51.dtsi respectively, so remove the board files.
This allows the conversion of mx51 to a devicetree-only platform.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Reviewed-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
R-Car M2 has two MSTP bits for SYS-DMAC, not one.
Also bring the naming in sync with the documentation.
This issue was introduced in v3.14, in commit
4d8864c9e9 ("ARM: shmobile: r8a7791: Add
clock index macros for DT sources").
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
There's no need to duplicate the interrupt-parent property in all DT
nodes as the kernel automatically walks parent nodes to find the
property. Specify it once in the root node only.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Add support for Broadwell processors.
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Improve the wording for the clock-indices binding documentation.
Also replace "empty nodes" by "empty strings", as reported before by Sergei
Shtylyov.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
- Remove spaces in front of TABs,
- Correct indentation for some CLK_* flag descriptions.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
With the addition of clock-indices, we need to change the renesas
clock implementation to use these instead of the local definition
of "renesas,clock-indices".
Since this will break booting with older device trees, we add a
simple auto-detection of which properties are present.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This finally removes all remaining SAMSUNG_CLOCK conditional code
from s3c24xx architectures.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
With the move to the common clock framework completed for s3c2410, s3c2440
and s3c2442, the legacy clock code for these machines can go away too.
This also includes the legacy dclk code, as all legacy users are converted.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Convert the machines using the s3c2410 to use the new driver based
on the common clock framework instead of the legacy Samsung clock driver.
As with the s3c244x, machines using the clkout output will need a fixup
from someone with the hardware.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Convert all machines using these cpus to use the ccf clock driver
instead of the legacy Samsung clock implementation.
Some of the more esotheric machines will probably need a fixup, as they
do strange things to the clkout outputs, that I did not really understand
nor have the hardware to check.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This adds the necessary init functions to init the clocks from the common
clock framework and necessary CONFIG_SAMSUNG_CLOCK ifdefs around the legacy
clock code.
This also includes empty stubs for the *_setup_clocks functions that are
called from the cpufreq driver on resume.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This driver can handle the clock controllers of the socs mentioned above,
as they share a common clock tree with only small differences.
The clock structure is built according to the manuals of the included
SoCs and might include changes in comparison to the previous clock
structure.
As pll-rate-tables only the 12mhz variants are currently included.
The original code was wrongly checking for 169mhz xti values [a 0 to much
at the end], so the original 16mhz pll table would have never been
included and its values are so obscure that I have no possibility to
at least check their sane-ness. When using the formula from the manual
the resulting frequency is near the table value but still slightly off.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Describe the clock controller of s3c2410, s3c2440 and s3c2442.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Add platform device and select the correct implementation automatically
depending on wether the old samsung_clock or the common clock framework
is enabled.
This is only done for machines already using the old dclk implementation,
as everybody else should move to use dt anyway.
The machine-specific settings for the external clocks will have to be set
by somebody with knowledge about the specific hardware.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
[pebolle@tiscali.nl: pointed out typo and fixed]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
<uapi/asm/inst.h> is exported to userland so the macro name BITFIELD_FIELD
pollutes the namespace. Prefix the name with __ fixes this.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Loongson2 has been using (incorrectly) kHz for cpu_clk rate. This has
been unnoticed, as loongson2_cpufreq was the only place where the rate
was set/get. After commit 652ed95d5f
(cpufreq: introduce cpufreq_generic_get() routine) things however broke,
and now loops_per_jiffy adjustments are incorrect (1000 times too long).
The patch fixes this by changing cpu_clk rate to Hz.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable@vger.kernel.org
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: cpufreq@vger.kernel.org
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Patchwork: https://patchwork.linux-mips.org/patch/6678/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 0e476d9124 ("MIPS: Loongson: Add Loongson-3 Kconfig options")
added "select GENERIC_HARDIRQS_NO__DO_IRQ". But the Kconfig symbol
GENERIC_HARDIRQS_NO__DO_IRQ was already removed in v2.6.38, so that
select is a nop. Drop it.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/6677/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This change reverts most of commit
60724ca59e [MIPS: IP checksums: Remove
unncessary .set pseudos] that introduced warnings with the
CPU_DADDI_WORKAROUNDS option set:
arch/mips/lib/csum_partial.S: Assembler messages:
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:467: Warning: used $3 with ".set at=$3"
[...]
arch/mips/lib/csum_partial.S:577: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:577: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:577: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:601: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:601: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:601: Warning: used $3 with ".set at=$3"
arch/mips/lib/csum_partial.S:601: Warning: used $3 with ".set at=$3"
[and so on, and so on...]
The warnings are benign and good code is produced regardless because no
macros that'd use the assembler's temporary register are involved, however
the `.set noat' directives removed by the commit referred are crucial to
guarantee this is still going to be the case after any changes in the
future. Therefore they need to be brought back to place which this
change does.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6686/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This corrects assembler warnings and broken code generated in
__strncpy_from_user_asm:
arch/mips/lib/strncpy_user.S: Assembler messages:
arch/mips/lib/strncpy_user.S:52: Warning: Macro instruction expanded into
multiple instructions in a branch delay slot
with the CPU_DADDI_WORKAROUNDS option set. The function schedules delay
slots manually where there is really no need to as GAS is happy to do it
all itself, so undo it all and remove `.set noreorder'.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6685/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With CPU_DADDI_WORKAROUNDS enabled __delay assembles with a macro in a
branch delay slot:
{standard input}: Assembler messages:
{standard input}:18: Warning: Macro instruction expanded into multiple
instructions in a branch delay slot
and broken code results:
0000000000000000 <__delay>:
0: 1480ffff bnez a0,0 <__delay>
4: 24010001 li at,1
8: 0081202f dsubu a0,a0,at
c: 03e00008 jr ra
10: 00000000 nop
14: 00000000 nop
Consequently the function loops indefinitely, showing up prominently as a
hang in the delay loop calibration at bootstrap.
This change corrects the problem by forcing the immediate 1 into a
register while keeping code produced identical where CPU_DADDI_WORKAROUNDS
is disabled.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6669/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 231a35d372 [[MIPS] RM: Collected
changes] broke DECstation support by introducing an incompatible copy of
arch/mips/dec/prom/call_o32.S in arch/mips/fw/lib/, built unconditionally.
The copy happens to land earlier of the two among the modules used in the
link and is therefore chosen for the DECstation rather than the intended
original. As a result random kernel data is corrupted because a pointer
to the "%s" formatted output template is used as a temporary stack pointer
rather than being passed down to prom_printf. This also explains why
prom_printf still works, up to a point -- the next argument is the actual
string to output so it works just fine as the output template until enough
kernel data has been corrupted to cause a crash.
This change adjusts the modified wrapper in arch/mips/fw/lib/call_o32.S to
let callers request no stack switching by passing a null temporary stack
pointer in $a1, reworks the DECstation callers to work with the updated
interface and removes the old copy from arch/mips/dec/prom/call_o32.S. A
few minor readability adjustments are included as well, most importantly
O32_SZREG is now used throughout where applicable rather than hardcoded
multiplies of 4 and $fp is used to access the argument save area as a more
usual register to operate the stack with rather than $s0.
Finally an update is made to the temporary stack space used by the SNI
platform to guarantee 8-byte alignment as per o32 requirements.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6668/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 69f24d1784 [MIPS: Optimize
current_cpu_type() for better code.] missed an update for two DECstation
bus error support files that now do not build, this is a fix.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6667/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add mailing list and patchwork URL so patches now have a defined path.
Also add myself as a TURBOchannel maintainer. However Maciej is going
to the the resident TURBOchannel guru.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: "Maciej W. Rozycki" <macro@linux-mips.org>
Reverts commit 795038a691 because
d6d3c9afaa provides the same functionality
in a more generic way. Both patches applied however means that the
VPE and TC IDs get printed twice currently.
We don't need to change those dividers if bclk and mclk remains the same
directions and values.
Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
According to Reference Manual -- ESAI Initialization chapter, as the
standard procedure of ESAI personal reset, the PCRC and PRRC registers
should be remained in its reset value and then configured after T/RCCR
and T/RCR configurations's done but before TE/RE's enabling.
So this patch moves PCRC and PRRC settings to the end of hw_params().
Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
ESAI can only output EXTAL clock source directly. But for FSYS clock source,
ESAI can not output it without getting through PSR PM dividers.
So this patch adds an extra check in the code.
Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
The range here from 1 to 16 is confined to FP divider only while the
sck_div indicates if the calculation contains PSR and PM dividers. So
for the case using PSR and PM since the sck_div is true, the range of
ratio would simply become bigger than 16.
So this patch fixes the condition here and adds one line comments to
make the purpose here clear.
Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Update Ian Molton's email, the maintainer for tmio/sh_mobile_sdhci.
Cc: Ian Molton <ian.molton@codethink.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Ian Molton <ian.molton@codethink.co.uk>
Signed-off-by: Chris Ball <chris@printf.net>
Callers of mmc_regulator_get_supply could benefit from knowing if either
of the regulators are present but not yet available. Since callers do
not currently examine the return value, modify this function to return
zero or -EPROBE_DEFER if either regulator get returns the same.
Furthermore, since callers check vmmc/vqmmc using IS_ERR and can deal
with absent regulators, switch to devm_regulator_get_optional. This has
the added benefit of allowing this function to behave correctly even in
the !CONFIG_REGULATOR case such that the stub can be removed.
Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
This patch replaces regulator manipulation with
mmc_regulator_get_supply() function from MMC core.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Found using smatch:
drivers/mmc/host/atmel-mci.c:827 atmci_pdc_complete() warn: variable
dereferenced before check 'host->data' (see line 807)
Stop testing host->data as it is not NULL at that point.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
rtsx_usb_sdmmc module uses the LED classdev if available, but the code
failed to consider the situation that it is built-in and the LED classdev is a
module, leading to following linking error:
LD init/built-in.o
drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_remove':
rtsx_usb_sdmmc.c:(.text+0x2a018e): undefined reference to
`led_classdev_unregister'
drivers/built-in.o: In function `rtsx_usb_sdmmc_drv_probe':
rtsx_usb_sdmmc.c:(.text+0x2a197e): undefined reference to
`led_classdev_register'
Fix by excluding such condition when defining macro RTSX_USB_USE_LEDS_CLASS.
Signed-off-by: Roger Tseng <rogerable@realtek.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Return -ENOSYS in get_cd if broken-cd is specified in the device tree.
Commit a91fe279ae (mmc: mxs: use standard flag for broken card
detection) sets MMC_CAP_NEEDS_POLL when broken-cd is specified. This
driver sets this flag unconditionally as it does not support a card
detect interrupt. Instead, broken-cd means that there is no card detect
signal connected.
The mmc core checks the get_cd function return value to determine if a
card is present. Only for a non-zero return value it will attempt to
initialize the card. So retuning -ENOSYS will allow the card to be
initialized.
For comparison, mmc_gpio_get_cd in slot-gpio.c also returns -ENOSYS if
the card detect GPIO is not valid.
Signed-off-by: Daniel Willmann <daniel@totalueberwachung.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
As of commit bcc3e1726d ("mmc: block: Use R1 responses for stop cmds for
read requests"), stop commands for reads do not have MMC_RSP_BUSY set.
In this case we should not wait for a PRG_DONE IRQ after sending the
stop command: it will not get raised when the busy flag is not set,
causing the request to fail with a timeout.
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Chris Ball <chris@printf.net>
Cc: James Hogan <james.hogan@imgtec.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Provide the option to configure these speed modes per host,
for those host driver's that can't distinguish this in runtime.
Specially, if host can support HS400, it means that host can also
support HS200.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
This patch adds HS400 mode support for eMMC5.0 device. HS400 mode is high
speed DDR interface timing from HS200. Clock frequency is up to 200MHz
and only 8-bit bus width is supported. In addition, tuning process of
HS200 is required to synchronize the command response on the CMD line
because CMD input timing for HS400 mode is the same as HS200 mode.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Jackey Shen <jackey.shen@amd.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Current implementation for bus speed mode selection is too
complicated. This patch is to simplify the codes and remove
some duplicate parts.
The following changes are including:
* Adds functions for each mode selection(HS, HS-DDR, HS200 and etc)
* Rearranged the mode selection sequence with supported device type
* Adds maximum speed for HS200 mode(hs200_max_dtr)
* Adds field definition for HS_TIMING of EXT_CSD
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Power class is changed once only after selection of bus modes
including speed and bus-width finishes finally.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Device types which are supported by both host and device can be
identified when EXT_CSD is read. There is no need to check host's
capability anymore.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Timing mode identifier has same role and can take the place
of speed mode. This change removes all related speed mode.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
SDIO controllers found on Marvell Kirkwood SoCs seem to cause a late,
spurious irq although all interrupts have been disabled. This irq
doesn't do any harm, neither to HW nor driver. To avoid some
"unexpected irq" warning later, we workaround above issue by bailing
out of irq handler early, if we didn't expect any.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
mvsdio reports method of card detection with dev_notice, while for
removable cards it may be sane, for non-removable cards it is not.
Also, as the user cannot do anything about it, silence the message
by reducing it from dev_notice to dev_dbg.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
The eMMC signalling voltage is determined by VCCQ which is provided to
the card by the host. Signalling is not required to begin at 3.3v and,
if the host and card both support a particular VCC/VCCQ combination, it
can be used immediately.
In contrast, SD Cards must begin with 3.3v signalling and may switch to
a lower voltage signalling if instructed to do so in CMD11. A message
is required to coordinate this operation because the card only receives
a 3.3v VDD and must know when to use the 1.8v produced by its internal
regulator.
It makes sense for the core to begin with 3.3v signalling but when that
can't be set, 1.8v and 1.2v signalling also should be attempted. This
is especially important when an external regulator with a limited range
is used to supply VCCQ to an eMMC part.
Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
