[PATCH v5 0/4] spi: pxa2xx: Pass the SSP type via device property

From: Andy Shevchenko
Date: Fri Oct 21 2022 - 15:00:34 EST


Currently the SPI PXA2xx devices on Intel platforms can be instantiated
via the following paths:
1) as ACPI LPSS device on Haswell, Bay Trail and Cherry Trail;
2) as ACPI LPSS device on the Sky Lake and newer;
3) as PCI LPSS device on Haswell, Bay Trail and Cherry Trail;
4) as PCI LPSS device on the Sky Lake and newer;
5) as PCI device via ID table.

Each of these cases provides some platform related data differently,
i.e.:
1) via drivers/acpi/acpi_lpss.c and drivers/spi/spi-pxa2xx.c
2) via drivers/mfd/intel-lpss-acpi.c
3) via drivers/spi/spi-pxa2xx-pci.c
4) via drivers/mfd/intel-lpss-pci.c and drivers/spi/spi-pxa2xx.c
5) via drivers/spi/spi-pxa2xx-pci.c

This approach has two downsides:

a) there is no data propagated in the case #2 because we can't have
two or more drivers to match the same ACPI ID and hence some cases
are still not supported (Sky Lake and newer ACPI enabled LPSS);

b) the data is duplicated over two drivers in the cases #1 & #4 and,
besides to be a bloatware, it is error prone (e.g. Lakefield has
a wrong data right now due to missed PCI entry in the spi-pxa2xx.c).

This series fixes the downsides, and enables previously unsupported
cases. On top of that it has a couple of cleanups (patches 4 and 5).

Changelog v5:
- added a patch to validate the SSP type
- reworked LPSS detection code to narrow its scope (Mark)
- dropped applied patches

Changelog v4:
- apply the property only for known MFD enumerated devices (Mark)

Changelog v3:
- added tags to patches 4 & 5 (Jonathan)
- massaged cover letter

Changelog v2:
- added cover letter (Mark)
- dropped applied patch

Andy Shevchenko (4):
spi: pxa2xx: Validate the correctness of the SSP type
spi: pxa2xx: Respect Intel SSP type given by a property
spi: pxa2xx: Remove no more needed PCI ID table
spi: pxa2xx: Move OF and ACPI ID tables closer to their user

drivers/spi/spi-pxa2xx.c | 171 ++++++++-----------------------------
include/linux/pxa2xx_ssp.h | 1 +
2 files changed, 37 insertions(+), 135 deletions(-)

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2.35.1