This patch restores the suspend and resume hooks that the old driver used
to have. Apart from stopping and starting the clocks, the resume callback
also nullifies the selected_chip pointer, so the next command that is issued
will re-select the chip and thereby restore the timing registers.
Factor out some code from marvell_nfc_init() into a new function
marvell_nfc_reset() and also call it at resume time to reset some registers
that don't retain their contents during low-power mode.
Without this patch, a PXA3xx based system would cough up an error similar to
the one below after resume.
[ 44.660162] marvell-nfc 43100000.nand-controller: Timeout waiting for RB signal
[ 44.671492] ubi0 error: ubi_io_write: error -110 while writing 2048 bytes to PEB 102:38912, written 0 bytes
[ 44.682887] CPU: 0 PID: 1417 Comm: remote-control Not tainted 4.18.0-rc2+ #344
[ 44.691197] Hardware name: Marvell PXA3xx (Device Tree Support)
[ 44.697111] Backtrace:
[ 44.699593] [<c0106458>] (dump_backtrace) from [<c0106718>] (show_stack+0x18/0x1c)
[ 44.708931] r7:00000800 r6:00009800 r5:00000066 r4:c6139000
[ 44.715833] [<c0106700>] (show_stack) from [<c0678a60>] (dump_stack+0x20/0x28)
[ 44.724206] [<c0678a40>] (dump_stack) from [<c0456cbc>] (ubi_io_write+0x3d4/0x630)
[ 44.732925] [<c04568e8>] (ubi_io_write) from [<c0454428>] (ubi_eba_write_leb+0x690/0x6fc)
...
Fixes: 02f26ecf8c77 ("mtd: nand: add reworked Marvell NAND controller driver")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
bd9c3f9b3c