i2c: mchp-pci1xxxx: Avoid cast to incompatible function type

Rather than casting pci1xxxx_i2c_shutdown to an incompatible function type,
update the type to match that expected by __devm_add_action.

Reported by clang-16 with W-1:

.../i2c-mchp-pci1xxxx.c:1159:29: error: cast from 'void (*)(struct pci1xxxx_i2c *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]
ret = devm_add_action(dev, (void (*)(void *))pci1xxxx_i2c_shutdown, i2c);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/device.h:251:29: note: expanded from macro 'devm_add_action'
__devm_add_action(release, action, data, #action)
^~~~~~

No functional change intended.
Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Reviewed-by: Tharun Kumar P<tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: mchp-pci1xxxx: Update Timing registers

Update I2C timing registers based on latest hardware design.
This fix does not break functionality of chips with older design and
existing users will not be affected.

Fixes: 361693697249 ("i2c: microchip: pci1xxxx: Add driver for I2C host controller in multifunction endpoint of pci1xxxx switch")
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: microchip: pci1xxxx: Fix comparison of -EPERM against an unsigned variable

The comparison of variable ret with -EPERM is always false because
ret is an u8 type. Fix this by making ret an int.

Cleans up clang warning:
drivers/i2c/busses/i2c-mchp-pci1xxxx.c:714:10: warning: result of comparison
of constant -1 with expression of type 'u8' (aka 'unsigned char') is always
false [-Wtautological-constant-out-of-range-compare]

Fixes: 361693697249 ("i2c: microchip: pci1xxxx: Add driver for I2C host controller in multifunction endpoint of pci1xxxx switch")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: pci1xxxx: prevent signed integer overflow

Some constants need 'UL' markings, otherwise they are shifted into the
sign bit.

Fixes: 361693697249 ("i2c: microchip: pci1xxxx: Add driver for I2C host controller in multifunction endpoint of pci1xxxx switch")
Signed-off-by: Wolfram Sang <wsa@kernel.org>

i2c: microchip: pci1xxxx: Add driver for I2C host controller in multifunction endpoint of pci1xxxx switch

Microchip pci1xxxx is an unmanaged PCIe3.1a Switch for Consumer,
Industrial and Automotive applications. This switch has multiple
downstream ports. In one of the Switch's Downstream port, there
is a multifunction endpoint for peripherals which includes an I2C
host controller. The I2C function in the endpoint operates at 100KHz,
400KHz and 1 MHz and has buffer depth of 128 bytes.
This patch provides the I2C controller driver for the I2C function
of the switch.

Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>