Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 19 8月, 2014 1 次提交
    • J
      regmap: Fix DT endianess parsing logic · ba1b53fe
      由 Javier Martinez Canillas 提交于 
      Commit d647c199 ("regmap: add DT endianness binding support.")
added support to parse the device endianness from the device tree
but unfortunately the added logic doesn't have the same semantics
than the old code. This leads to a NULL dereference pointer error
when these properties are not provided by the Device Tree:

Unable to handle kernel NULL pointer dereference at virtual address 00000044
pgd = c0004000
[00000044] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc1-next-20140818ccu #671
task: ea412800 ti: ea484000 task.ti: ea484000
PC is at regmap_update_bits+0xc/0x5c

The problem is that platforms that rely on the default value now
gets different values due two related issues in the current code:

a) It only parses the endianness from DT for the regmap registers
   and not for the regmap values but it checks unconditionally in
   both cases if the resulting endiannes is REGMAP_ENDIAN_NATIVE.

b) REGMAP_ENDIAN_NATIVE is not even a valid DT property according
   to the regmap DT binding documentation so it shouldn't be set.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NMark Brown <broonie@linaro.org>
      ba1b53fe
  3. 17 8月, 2014 3 次提交
    • X
      regmap: Add the DT binding documentation for endianness · 275876e2
      由 Xiubo Li 提交于 
      Device-Tree binding for device endianness
Index     Device     Endianness properties
---------------------------------------------------
1         BE         'big-endian'
2         LE         'little-endian'

For one device driver, which will run in different scenarios above
on different SoCs using the devicetree, we need one way to simplify
this.
Signed-off-by: NXiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: NMark Brown <broonie@linaro.org>
      275876e2
    • X
      regmap: add DT endianness binding support. · d647c199
      由 Xiubo Li 提交于 
      For many drivers which will support rich endianness of Devices
need define DT properties by itself with the binding support.

The endianness using regmap:
Index      Device     Properties if needs bytes-swap,
                      or just ignore it
-------------------------------------------------------------
1          BE         'big-endian'
2          LE         'little-endian'

The properties include all the register values and the buffers.
And these properties are very usful for the MMIO devices:

Such as: a memory-mapped device, on one SoC is in BE mode, while
in another SoC will be in LE mode, and the CPU will always in LE
mode.

For the first case, we must use cpu_to_be32/be32_to_cpu for
32-bit registers accessing, so the 'big-endian' property is needed.

For the second case, we can just ignore the bytes-swap
functions like cpu_to_le32/le32_to_cpu, so the 'little-endian'
property could be abscent.

And vice versa...
Signed-off-by: NXiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: NMark Brown <broonie@linaro.org>
      d647c199
    • L
      Linux 3.17-rc1 · 7d1311b9
      由 Linus Torvalds 提交于
      7d1311b9
  5. 16 8月, 2014 36 次提交