Commit graph

133 commits

Author SHA1 Message Date
Alper Nebi Yasak
2a1d7c635f mmc: sdhci: Add HS400 Enhanced Strobe support
Delegate setting the Enhanced Strobe configuration to individual drivers
if they set a function for it. Return -ENOTSUPP if they do not, like
what the MMC uclass does.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
2022-03-16 18:10:19 +09:00
Stephen Carlson
40e6f52454 drivers: mmc: Add wait_dat0 support for sdhci driver
Adds an implementation of the wait_dat0 MMC operation for the DM SDHCI
driver, allowing the driver to continue when the card is ready rather
than waiting for the worst case time on each MMC switch operation.

Signed-off-by: Stephen Carlson <stcarlso@linux.microsoft.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
2021-10-29 18:22:32 +09:00
Yuezhang.Mo@sony.com
4a3ea75de4 Revert "mmc: sdhci: set to INT_DATA_END when there are data"
This reverts commit 17ea3c8628.

In eMMC specification, for the response-with-busy(R1b, R5b)
command, the DAT0 will driven to LOW as BUSY status, and in
sdhci specification, the transfer complete bit should be wait
for BUSY status de-assert.

All response-with-busy commands don't contain data, the data
judgement is no need.

Signed-off-by: Yuezhang.Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2021-09-10 18:13:34 +08:00
Ashok Reddy Soma
16b593bec7 mmc: sdhci: Change prototype of set_delay to return errors
set_delay() has return type as void. If there are any errors while
setting tapdelay's it won't be able to return them.

Change the prototype of set_delay() in sdhci_ops structure and return
the errors from wherever it is called.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2021-08-06 09:35:34 +02:00
Faiz Abbas
bda47bef7c mmc: sdhci: Write to HOST_CONTROL2 register for HS400 speed mode
Enable HS400 speed mode by writing to HOST_CONTROL2 register.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Link: https://lore.kernel.org/r/20210405144428.12159-1-a-govindraju@ti.com
2021-07-27 10:56:09 +05:30
Yuezhang.Mo@sony.com
37e1362efc mmc: sdhci: skip cache invalidation if DMA is not used
If DMA(SDMA or ADMA) is not used, the cache invalidation
after reading is no need, should be skipped. Otherwise
U-Boot may hang at the cache invalidation.

Found this issue and tested this fix on DragonBoard 410c.

Fixes: commit 4155ad9aac ("mmc: sdhci: fix missing cache invalidation after reading by DMA")

Signed-off-by: Yuezhang.Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
2021-02-19 15:03:25 +08:00
Nicolas Saenz Julienne
c89c96d322 mmc: Introduce mmc_phys_to_bus()/mmc_bus_to_phys()
This will allow us to use DM variants of phys_to_bus()/bus_to_phys()
when relevant.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
2021-02-18 11:59:08 +01:00
Faiz Abbas
43392b550e mmc: sdhci: Add helper functions for UHS modes
Add a set_voltage() function which handles the switch from 3.3V to 1.8V
for SD card UHS modes.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2021-02-04 20:37:57 +05:30
Ashok Reddy Soma
7a49a16ec5 Revert "mmc: zynq: parse dt when probing"
This reverts commit 942b5fc032.

This is partial revert of the above commit.

mmc_of_parse() is reading no-1-8-v from device tree and if set,
it is clearing the UHS speed capabilities of cfg->host_caps.
cfg->host_caps &= ~(UHS_CAPS | MMC_MODE_HS200 |
		    MMC_MODE_HS400 | MMC_MODE_HS400_ES);

This is still missing to clear UHS speeds like SDHCI_SUPPORT_SDR104,
SDHCI_SUPPORT_SDR50 and SDHCI_SUPPORT_DDR50.

Even if we clear the flags SDHCI_SUPPORT_XXX in mmc_of_parse(),
these speed flags are getting set again in cfg->host_caps in
sdhci_setup_cfg().

The reason for this is, SDHCI_SUPPORT_XXX flags are cleared
only if controller is not capable of supporting MMC_VDD_165_195 volts.

if (caps & SDHCI_CAN_VDD_180)
	cfg->voltages |= MMC_VDD_165_195;

if (!(cfg->voltages & MMC_VDD_165_195))
	caps_1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
		    SDHCI_SUPPORT_DDR50);

It means "no-1-8-v", which is read from DT is not coming in to effect.
So it is better we keep the host quirks(SDHCI_QUIRK_NO_1_8_V) to
clear UHS speeds based on no-1-8-v from device tree.

Hence revert the functionality related to no-1-8-v only, rest is fine
in the patch.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
2020-10-27 08:13:33 +01:00
Michael Walle
4d6a773b1c mmc: sdhci: move the ADMA2 table handling into own module
There are other (non-SDHCI) controllers which supports ADMA2 descriptor
tables, namely the Freescale eSDHC. Instead of copying the code, move it
into an own module.

Signed-off-by: Michael Walle <michael@walle.cc>
2020-10-12 15:50:19 +08:00
Michal Simek
b5a3387dc1 mmc: sdhci: Use upper/lower_32_bits macros
Instead of recasting and shifting use macros which are designed for taking
upper/lower 32bit value from 64bit variable.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2020-08-20 09:58:59 +02:00
Faiz Abbas
620bb46ead mmc: sdhci: Enable high speed conditional on the corresponding bit
The capabilities register has a field to indicate whether the host
supports high speed mode or not. Add high speed host_caps based on
this bit instead of enabling it by default.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Reviewed-by: Michal Simek <michal.simek@xilnx.com>
Tested-by: Michal Simek <michal.simek@xilnx.com>
(zcu104 with sdhci-caps-mask = <0 0x200000>;)
2020-08-20 09:58:59 +02:00
Simon Glass
4426632dc8 mmc: Drop duplicate dm.h inclusion
We only need to include this header once. Drop the duplicate.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-08-03 22:19:54 -04:00
Jagan Teki
f12341a952 mmc: sdhci: Fix HISPD bit handling
SDHCI HISPD bits need to be configured based on desired mmc
timings mode and some HISPD quirks.

So, handle the HISPD bit based on the mmc computed selected
mode(timing parameter) rather than fixed mmc card clock
frequency.

Linux handle the HISPD similar like this in below commit but no
SDHCI_QUIRK_BROKEN_HISPD_MODE,

commit <501639bf2173> ("mmc: sdhci: fix SDHCI_QUIRK_NO_HISPD_BIT handling")

This eventually fixed the mmc write issue observed in
rk3399 sdhci controller.

Bug log for refernece,
=> gpt write mmc 0 $partitions
Writing GPT: mmc write failed
** Can't write to device 0 **
** Can't write to device 0 **
error!

Cc: Kever Yang <kever.yang@rock-chips.com>
Cc: Peng Fan <peng.fan@nxp.com>
Peng Fan: added back "ctrl &= ~SDHCI_CTRL_HISPD;" per Jaehoon's suggestion
Tested-by: Suniel Mahesh <sunil@amarulasolutions.com> # roc-rk3399-pc
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
2020-06-24 14:05:30 +08:00
Simon Glass
cd93d625fd common: Drop linux/bitops.h from common header
Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 21:19:23 -04:00
Simon Glass
c05ed00afb common: Drop linux/delay.h from common header
Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 21:19:23 -04:00
Simon Glass
f7ae49fc4f common: Drop log.h from common header
Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 21:19:18 -04:00
Simon Glass
90526e9fba common: Drop net.h from common header
Move this header out of the common header. Network support is used in
quite a few places but it still does not warrant blanket inclusion.

Note that this net.h header itself has quite a lot in it. It could be
split into the driver-mode support, functions, structures, checksumming,
etc.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 17:33:31 -04:00
Matthias Brugger
7acdc9aa09 mmc: sdhci: Use debug for not supported SDMA info message
If CONFIG_MMC_SDHCI_SDMA is enabled but the HW could not support it,
we no longer error out. Instead we do not enable it in the host.
Change the output from printf to debug as this isn't an error but only
additional information now.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
2020-05-13 13:54:23 +02:00
Jaehoon Chung
fabb3a43ad mmc: sdhci: not return error when SDMA is not supported
If Host controller doesn't support SDMA, it doesn't need to return
error. Because it can be worked with PIO mode.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
2020-05-12 11:01:14 +02:00
Jaehoon Chung
fac8bfd4f5 mmc: sdhci: use phys2bus macro when dma address is accessed
Use phys2bus macro when dma address is accessed.
Some targets need to use pyhs2bus macro. (e.g, RPI4)
After applied it, SDMA mode can be used.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
2020-05-12 11:00:45 +02:00
Benedikt Grassl
942b5fc032 mmc: zynq: parse dt when probing
Currently, the entry "bus-width = <8>" in the ZynqMP's sdhci nodes
is not evaluated. This results in the bus width staying at its default
value (4 bit in HS200 mode).
Fix this by calling mmc_of_parse. This function also checks for the
"no-1-8-v" and "max-frequency" entries. Remove the handling of those
nodes from this driver.

Signed-off-by: Benedikt Grassl <Benedikt.Grassl@rohde-schwarz.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2020-04-27 13:53:13 +02:00
Faiz Abbas
cb884347f4 sdhci: Add sdhci_deferred_probe() API
Add the sdhci_deferred_probe() function to register as the
deferred_probe() callback to the mmc core. It will in turn call the
deferred_probe() callback of the platform drivers as declared in the
sdhci_ops.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
2020-03-09 08:33:16 +08:00
Masahiro Yamada
4155ad9aac mmc: sdhci: fix missing cache invalidation after reading by DMA
This driver currently performs cache operation before the DMA start,
but does nothing after the DMA completion.

When reading data by DMA, the cache invalidation is needed also after
finishing the DMA transfer. Otherwise, the CPU might read data from
the cache instead of from the main memory when speculative memory read
or memory prefetch occurs.

Instead of calling the cache operation directly, this commit adds
dma_unmap_single(), which performs cache invalidation internally,
but drivers do not need which operation is being run.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2020-02-20 15:09:57 +08:00
Masahiro Yamada
58d8ace12b mmc: sdhci: use dma_map_single() instead of flush_cache() before DMA
Currently, sdhci_prepare_dma() calls flush_cache() regardless of the
DMA direction.

Actually, cache invalidation is enough when reading data from the device.

This is correctly handled by dma_map_single(), which mimics the DMA-API
in Linux kernel. Drivers can be agnostic which cache operation occurs
behind the scene.

This commit also sanitizes the difference between the virtual address
and the dma address.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2020-02-20 15:09:57 +08:00
Masahiro Yamada
fdd84c8be4 mmc: sdhci: remove unneeded casts
host->mmc is already (struct mmc *).

memalign() returns an opaque pointer, so there is no need for casting.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2020-02-20 15:09:56 +08:00
Masahiro Yamada
a2b0221c9c mmc: sdhci: use lower_32_bit2() and upper_32_bits() for setting adma_addr
Use {lower,upper}_32_bits() instead of the combination of cast
and shift.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2020-02-20 15:09:55 +08:00
Masahiro Yamada
f5df6aa1e6 mmc: sdhci: reduce code duplication for aligned buffer
The same code is run for both SDHCI_QUIRK_32BIT_DMA_ADDR and
define(CONFIG_FIXED_SDHCI_ALIGNED_BUFFER).

Unify the code.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2020-02-20 15:09:55 +08:00
Masahiro Yamada
c8cc18b7a7 mmc: sdhci: put the aligned buffer pointer to struct sdhci_host
Using the global variable does not look nice.

Add a new field sthci::align_buffer to point to the bounce buffer.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
2020-02-20 15:09:54 +08:00
Simon Glass
1eb69ae498 common: Move ARM cache operations out of common.h
These functions are CPU-related and do not use driver model. Move them to
cpu_func.h

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2019-12-02 18:24:58 -05:00
Baruch Siach
1b71695228 mmc: sdhci: make sdhci_get_cd static
sdhci_get_cd() is not referenced anywhere else. Limit its scope to
sdhci.c.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
2019-11-27 16:55:19 +08:00
T Karthik Reddy
cd45d6f395 mmc: sdhci: Add support for dt caps & caps mask
The sdhci capabilities registers can be incorrect. The
sdhci-caps-mask and sdhci-caps dt properties specify which bits of
the registers are incorrect and what their values should be. This
patch makes the sdhci driver use those properties to correct the caps.
Also use "dev_read_u64_default" instead of "dev_read_u32_array" for
caps mask.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2019-09-06 10:40:13 +08:00
Baruch Siach
58d65d5082 mmc: sdhci: fix chip detect gpio property name
The standard property name for chip-detect gpio is "cd-gpios". All
in-tree DT files use only this name.

Fixes: 451931ea70 ("mmc: sdhci: Read cd-gpio from devicetree")
Cc: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
2019-07-31 15:31:36 +08:00
Faiz Abbas
d1c0a2200a mmc: sdhci: Add support for HOST_CONTROL2 and setting UHS timings
The HOST_CONTROL2 register is a part of SDHC v3.00 and not just specific
to arasan/zynq controllers. Add the same to sdhci.h.

Also create a common API to set UHS timings in HOST_CONTROL2.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2019-07-17 11:12:08 -04:00
Faiz Abbas
a8185c50d3 mmc: sdhci: Make set_ios_post() return int
Make set_ios_post() return int to faciliate error handling in
platform drivers.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
2019-07-17 11:12:08 -04:00
Faiz Abbas
3966c7d006 mmc: sdhci: Make sdhci_set_clock() non static
The am654_sdhci driver needs to switch the clock off
before disabling its phy dll and needs to re-enable
the clock before enabling the phy again.

Therefore, make the sdhci_set_clock() function accessible
in the am654_sdhci driver.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2019-07-17 11:12:08 -04:00
Faiz Abbas
3d296365e4 mmc: sdhci: Add support for sdhci-caps-mask
Add Support for masking some bits in the capabilities
register of a host controller.

Also remove the redundant readl() into caps1.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2019-07-17 11:12:08 -04:00
T Karthik Reddy
da18c62b6e mmc: sdhci: Implement SDHCI card detect
Card detect function implemented for SDHCI framework.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2019-07-15 10:16:49 +08:00
T Karthik Reddy
451931ea70 mmc: sdhci: Read cd-gpio from devicetree
This patch reads cd-gpio property from devicetree

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
2019-07-15 10:16:49 +08:00
Faiz Abbas
37cb626da2 mmc: sdhci: Add Support for ADMA2
The Standard Host Controller Interface (SDHCI) specification version
3.00 adds support for Advanced DMA (ADMA) for both 64 and 32 bit widths
of DMA. ADMA2 uses a table of descriptors for aggregating DMA requests.
This significantly improves read and write throughput.

Add Support for the same.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
2019-05-03 20:44:11 +08:00
Faiz Abbas
6d6af20571 mmc: sdhci: Move DMA handling to prepare_dma() function
In preparation for addition of ADMA2 support, cleanup SDMA handling by
moving it to a new sdhci_prepare_dma() function. Also add a flags field
in sdhci_host to indicate if DMA is enabled.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
2019-05-03 20:43:50 +08:00
Siva Durga Prasad Paladugu
1a7414f626 mmc: sdhci: Fix MMC HS200 tuning command failures
This patch fixes the mmc tuning command failures
when tuning pattern data needs to read back for
comparision against the expected bit pattern.

Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-15 08:54:04 +02:00
Siva Durga Prasad Paladugu
434f9d454e mmc: sdhci: Update sdhci_send_command() to handle HS200
This patch updates sdhci_send_command() to handle MMC
HS200 tuning command.

Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2018-05-31 13:50:39 +02:00
Ramon Fried
b70fe965bb mmc: sdhci: Check that ops are defined
The check is necessary to avoid NULL pointer dereference.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
2018-05-14 21:28:38 -04:00
Siva Durga Prasad Paladugu
b8e25ef16a mmc: sdhci: Read capabilities register1 and update host caps
This patch reads the capabilities register1 and update the host
caps accordingly for mmc layer usage. This patch mainly reads
for UHS capabilities inorder to support SD3.0.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2018-05-11 10:22:26 +02:00
Siva Durga Prasad Paladugu
ca992e82e4 mmc: sdhci: Invoke platform specific tuning and delay routines
This patch adds support to invoke any platform specific tuning
and delay routines if available.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2018-05-11 09:38:27 +02:00
Siva Durga Prasad Paladugu
b88a7a4c56 mmc: sdhci: Handle execute tuning command in sdhci_send_command
This patch upadted sdhci_send_command to handle execute tuning
command.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2018-05-11 09:38:27 +02:00
Siva Durga Prasad Paladugu
2a2d7efe77 mmc: sdhci: Add support for disabling clock
This patch adds support to disable clock if clk_disable
was set and then enable or set clock if the clock was changed
or clock was disabled when clock needs to be enabled.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2018-05-11 09:38:27 +02:00
Vipul Kumar
36332b6e4b mmc: Changed the datatype of the variable to handle 64-bit arch
This patch changed the datatype of variable "start" from uint to ulong
to work properly on 64-bit machines as well. Also the return type of
get_timer() function is ulong.

Signed-off-by: Vipul Kumar <vipul.kumar@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2018-05-11 09:38:27 +02:00
Tom Rini
83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00