[PATCH v3 0/6] clk: imx6: work around LDB hang caused by ERR009219

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Short version:

barebox always reparents the ldb_di[01] clocks to pll5_video_div.
Due to a hardware erratum, this can trigger a glitch that causes
LDB lock up.

Thus:

1) remove the automatic reparenting, like the kernel now does and
   mark the affected clocks read only, so assigned-clock-parents
   can't affect them
2) parse assigned-clock-parents in the clk-imx6 code as well, but
   there use a convoluted non-glitchy work around to apply them

Long version available alongside v1 here:
https://www.spinics.net/lists/u-boot-v2/msg37658.html
and in the commit messages of the patches.
v2 is available here:
https://www.spinics.net/lists/u-boot-v2/msg37970.html

Changes since v2:
 - reordered commits to avoid intermittent breakage, final
   diff unaffected
 - prepended a commit fixing premature use of cpu_is_mx6
 - fixed brace placement of cpu_(mx6_)?has_err009219
 - changed commits to use cpu_mx6_is_mx6*, all suggested by Andrey
 - updated commit messages, collected Andrey's Tested-By and
   Philipp's Reviewed-By

Changes since v1:
 - reordered/squashed commits after discussion with Sascha and Phillip
 - removed superfluous comment
 - add MUX_READ_ONLY at the correct place in the MUX_READ_ONLY arguments

Except for the last two, the total diff, is exactly the same
as v1's.

Ahmad Fatoum (3):
  clk: imx6: fix use of cpu_is_mx6* before they are initialized
  clk: imx6: remove quirky clk_set_parent(LDB_diN_sel, pll5_video_div)
  clk: imx6: define an enum for ldb mux inputs

Fabio Estevam (1):
  clk: imx6: Fix procedure to switch the parent of LDB_DI_CLK

Philipp Zabel (2):
  clk: imx6: Mask mmdc_ch1 handshake for periph2_sel and
    mmdc_ch1_axi_podf
  clk: imx6: Make the LDB_DI0 and LDB_DI1 clocks read-only

 drivers/clk/imx/clk-imx6.c | 329 ++++++++++++++++++++++++++++++++++---
 drivers/clk/imx/clk.h      |   8 +
 2 files changed, 317 insertions(+), 20 deletions(-)

-- 
2.20.1


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