Replace devm_kasprintf() with dev_name() for the chip label. dev_name()
returns a stable pointer to the device name, so the separate allocation
and -ENOMEM check can be dropped.
Using dev_name() seems to be common for GPIO labels.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-9-rosenp@gmail.com
Shifting a 32-bit unsigned integer by 32 or more places is undefined
behavior in C. GPIO_MASK2 computes its shift amount as (gpio) * 2, and
for pins 16-31 in the OSRH/TSRH bank this yields shifts of 32-62.
While this happens to work on PowerPC because slw masks the shift count
to the low 5 bits, compilers performing value-range propagation may
assume the else branch is unreachable and optimize it away, or may
evaluate the shift as zero on other architectures via COMPILE_TEST.
Mask gpio to the 16-pin bank index so the shift stays within [0, 30].
The registers are banked (OSRL/TSRL for gpio 0-15, OSRH/TSRH for
gpio 16-31) with an identical 2-bit-per-pin layout from MSB to LSB,
so masking to the within-bank index preserves the intended behavior.
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-8-rosenp@gmail.com
Replace PPC-specific clrbits32()/setbits32() with local helpers using
ioread32be()/iowrite32be() which are equivalent on PPC since commit
894fa235eb ("powerpc: inline iomap accessors").
Add COMPILE_TEST as a result to increase compile coverage.
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-7-rosenp@gmail.com
Use gpio_generic_chip_init() to set up the PPC44x GPIO chip
instead of open-coding the basic get, set, locking and state handling.
Keep the PPC44x-specific direction callbacks because they still need to
program ODR and the OSR/TSR registers around the generic data and
direction registers.
Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-6-rosenp@gmail.com
Map the PPC44x GPIO register block through the platform device
resource instead of reparsing the firmware node directly.
The GPIO node now probes as a platform device, so use the
platform helper to keep resource handling aligned with the converted
driver model and to report mapping failures with the platform device
context.
Move ioremap up in order to avoid doing extra work in case of
-EPROBE_DEFER.
Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-5-rosenp@gmail.com
Replace the open-coded arch initcall registration with
module_platform_driver(). The initcall level changes from
arch_initcall to device_initcall, which is safe since the
driver no longer needs architecture-specific ordering.
Added MODULE info as a result, otherwise these warnings appear
ERROR: modpost: missing MODULE_LICENSE() in drivers/gpio/gpio-ppc4xx.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/gpio/gpio-ppc4xx.o
Assisted-by: Codex:GPT-5.5
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-4-rosenp@gmail.com
The kernel lost support for 4xx platforms and now only supports 44x.
Since this driver is being moved to drivers/gpio/ , take the opportunity
to modernize the name.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-3-rosenp@gmail.com
Move the ppc4xx gpio driver out of arch/powerpc/platforms/44x/ into
drivers/gpio/gpio-ppc44x.c. The driver has no architecture-specific
dependencies and follows the same pattern as other PowerPC GPIO
drivers already in drivers/gpio/ (e.g. gpio-mpc8xxx, gpio-mpc5200).
- Renamed Kconfig symbol from PPC4xx_GPIO to GPIO_PPC44X
- Updated ppc44x_defconfig and warp_defconfig to use the new symbol
- Marked the new option as tristate (was bool) since the driver
supports module build via module_platform_driver()
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260803223539.86303-2-rosenp@gmail.com
