The interrupt controller can detect only link changes. So in case an
external device generated a level based interrupt, then the interrupt
controller detected correctly the first edge. But the problem was that
the interrupt controller was detecting also the edge when the interrupt
was cleared. So it would generate another interrupt.
The fix for this is to clear the second interrupt but still check the
interrupt line status.
Fixes: c297561bc9 ("pinctrl: ocelot: Fix interrupt controller")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20221018070959.1322606-1-horatiu.vultur@microchip.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Back in the description of commit e440e30e26 ("arm64: dts: qcom:
sc7180: Avoid glitching SPI CS at bootup on trogdor") we described a
problem that we were seeing on trogdor devices. I'll re-summarize here
but you can also re-read the original commit.
On trogdor devices, the BIOS is setting up the SPI chip select as:
- mux special function (SPI chip select)
- output enable
- output low (unused because we've muxed as special function)
In the kernel, however, we've moved away from using the chip select
line as special function. Since the kernel wants to fully control the
chip select it's far more efficient to treat the line as a GPIO rather
than sending packet-like commands to the GENI firmware every time we
want the line to toggle.
When we transition from how the BIOS had the pin configured to how the
kernel has the pin configured we end up glitching the line. That's
because we _first_ change the mux of the line and then later set its
output. This glitch is bad and can confuse the device on the other end
of the line.
The old commit e440e30e26 ("arm64: dts: qcom: sc7180: Avoid
glitching SPI CS at bootup on trogdor") fixed the glitch, though the
solution was far from elegant. It essentially did the thing that
everyone always hates: encoding a sequential program in device tree,
even if it's a simple one. It also, unfortunately, got broken by
commit b991f8c362 ("pinctrl: core: Handling pinmux and pinconf
separately"). After that commit we did all the muxing _first_ even
though the config (set the pin to output high) was listed first. :(
I looked at ideas for how to solve this more properly. My first
thought was to use the "init" pinctrl state. In theory the "init"
pinctrl state is supposed to be exactly for achieving glitch-free
transitions. My dream would have been for the "init" pinctrl to do
nothing at all. That would let us delay the automatic pin muxing until
the driver could set things up and call pinctrl_init_done(). In other
words, my dream was:
/* Request the GPIO; init it 1 (because DT says GPIO_ACTIVE_LOW) */
devm_gpiod_get_index(dev, "cs", GPIOD_OUT_LOW);
/* Output should be right, so we can remux, yay! */
pinctrl_init_done(dev);
Unfortunately, it didn't work out. The primary reason is that the MSM
GPIO driver implements gpio_request_enable(). As documented in
pinmux.h, that function automatically remuxes a line as a GPIO. ...and
it does this remuxing _before_ specifying the output of the pin. You
can see in gpiod_get_index() that we call gpiod_request() before
gpiod_configure_flags(). gpiod_request() isn't passed any flags so it
has no idea what the eventual output will be.
We could have debates about whether or not the automatic remuxing to
GPIO for the MSM pinctrl was a good idea or not, but at this point I
think there is a plethora of code that's relying on it and I certainly
wouldn't suggest changing it.
Alternatively, we could try to come up with a way to pass the initial
output state to gpio_request_enable() and plumb all that through. That
seems like it would be doable, but we'd have to plumb it through
several layers in the stack.
This patch implements yet another alternative. Here, we specifically
avoid glitching the first time a pin is muxed to GPIO function if the
direction of the pin is output. The idea is that we can read the state
of the pin before we set the mux and make sure that the re-mux won't
change the state.
NOTES:
- We only do this the first time since later swaps between mux states
might want to preserve the old output value. In other words, I
wouldn't want to break a driver that did:
gpiod_set_value(g, 1);
pinctrl_select_state(pinctrl, special_state);
pinctrl_select_default_state();
/* We should be driving 1 even if "special_state" made the pin 0 */
- It's safe to do this the first time since the driver _couldn't_ have
explicitly set a state. In order to even be able to control the GPIO
(at least using gpiod) we have to have requested it which would have
counted as the first mux.
- In theory, instead of keeping track of the first time a pin was set
as a GPIO we could enable the glitch-free behavior only when
msm_pinmux_request_gpio() is in the callchain. That works an enables
my "dream" implementation above where we use an "init" state to
solve this. However, it's nice not to have to do this. By handling
just the first transition to GPIO we can simply let the normal
"default" remuxing happen and we can be assured that there won't be
a glitch.
Before this change I could see the glitch reported on the EC console
when booting. It would say this when booting the kernel:
Unexpected state 1 in CSNRE ISR
After this change there is no error reported.
Note that I haven't reproduced the original problem described in
e440e30e26 ("arm64: dts: qcom: sc7180: Avoid glitching SPI CS at
bootup on trogdor") but I could believe it might happen in certain
timing conditions.
Fixes: b991f8c362 ("pinctrl: core: Handling pinmux and pinconf separately")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20221014103217.1.I656bb2c976ed626e5d37294eb252c1cf3be769dc@changeid
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Pull interrupt updates from Thomas Gleixner:
"Core code:
- Provide a generic wrapper which can be utilized in drivers to
handle the problem of force threaded demultiplex interrupts on RT
enabled kernels. This avoids conditionals and horrible quirks in
drivers all over the place
- Fix up affected pinctrl and GPIO drivers to make them cleanly RT
safe
Interrupt drivers:
- A new driver for the FSL MU platform specific MSI implementation
- Make irqchip_init() available for pure ACPI based systems
- Provide a functional DT binding for the Realtek RTL interrupt chip
- The usual DT updates and small code improvements all over the
place"
* tag 'irq-core-2022-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
irqchip: IMX_MU_MSI should depend on ARCH_MXC
irqchip/imx-mu-msi: Fix wrong register offset for 8ulp
irqchip/ls-extirq: Fix invalid wait context by avoiding to use regmap
dt-bindings: irqchip: Describe the IMX MU block as a MSI controller
irqchip: Add IMX MU MSI controller driver
dt-bindings: irqchip: renesas,irqc: Add r8a779g0 support
irqchip/gic-v3: Fix typo in comment
dt-bindings: interrupt-controller: ti,sci-intr: Fix missing reg property in the binding
dt-bindings: irqchip: ti,sci-inta: Fix warning for missing #interrupt-cells
irqchip: Allow extra fields to be passed to IRQCHIP_PLATFORM_DRIVER_END
platform-msi: Export symbol platform_msi_create_irq_domain()
irqchip/realtek-rtl: use parent interrupts
dt-bindings: interrupt-controller: realtek,rtl-intc: require parents
irqchip/realtek-rtl: use irq_domain_add_linear()
irqchip: Make irqchip_init() usable on pure ACPI systems
bcma: gpio: Use generic_handle_irq_safe()
gpio: mlxbf2: Use generic_handle_irq_safe()
platform/x86: intel_int0002_vgpio: Use generic_handle_irq_safe()
ssb: gpio: Use generic_handle_irq_safe()
pinctrl: amd: Use generic_handle_irq_safe()
...
Pull pin control updates from Linus Walleij:
"There is nothing exciting going on, no core changes, just a few
drivers and cleanups.
New drivers:
- Cypress CY8C95x0 chip pin control support, along with an immediate
cleanup
- Mediatek MT8188 SoC pin control support
- Qualcomm SM8450 and SC8280XP LPASS (low power audio subsystem) pin
control support
- Qualcomm PM7250, PM8450
- Rockchip RV1126 SoC pin control support
Improvements:
- Fix some missing pins in the Armada 37xx driver
- Convert Broadcom and Nomadik drivers to use PINCTRL_PINGROUP()
macro
- Fix some GPIO irq_chips to be immutable
- Massive Qualcomm device tree binding cleanup, with more to come"
* tag 'pinctrl-v6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (119 commits)
MAINTAINERS: adjust STARFIVE JH7100 PINCTRL DRIVER after file movement
pinctrl: starfive: Rename "pinctrl-starfive" to "pinctrl-starfive-jh7100"
pinctrl: Create subdirectory for StarFive drivers
dt-bindings: pinctrl: st,stm32: Document interrupt-controller property
dt-bindings: pinctrl: st,stm32: Document gpio-hog pattern property
dt-bindings: pinctrl: st,stm32: Document gpio-line-names
pinctrl: st: stop abusing of_get_named_gpio()
pinctrl: wpcm450: Correct the fwnode_irq_get() return value check
pinctrl: bcm: Remove unused struct bcm6328_pingroup
pinctrl: qcom: restrict drivers per ARM/ARM64
pinctrl: bcm: ns: Remove redundant dev_err call
gpio: rockchip: request GPIO mux to pinctrl when setting direction
pinctrl: rockchip: add pinmux_ops.gpio_set_direction callback
pinctrl: cy8c95x0: Align function names in cy8c95x0_pmxops
pinctrl: cy8c95x0: Drop atomicity on operations on push_pull
pinctrl: cy8c95x0: Lock register accesses in cy8c95x0_set_mux()
pinctrl: sunxi: sun50i-h5: Switch to use dev_err_probe() helper
pinctrl: stm32: Switch to use dev_err_probe() helper
dt-bindings: qcom-pmic-gpio: Add PM7250B and PM8450 bindings
pinctrl: qcom: spmi-gpio: Add compatible for PM7250B
...
Pull ARM driver updates from Arnd Bergmann:
"The drivers branch for 6.1 is a bit larger than for most releases.
Most of the changes come from SoC maintainers for the drivers/soc
subsystem:
- A new driver for error handling on the NVIDIA Tegra 'control
backbone' bus.
- A new driver for Qualcomm LLCC/DDR bandwidth measurement
- New Rockchip rv1126 and rk3588 power domain drivers
- DT binding updates for memory controllers, older Rockchip SoCs,
various Mediatek devices, Qualcomm SCM firmware
- Minor updates to Hisilicon LPC bus, the Allwinner SRAM driver, the
Apple rtkit firmware driver, Tegra firmware
- Minor updates for SoC drivers (Samsung, Mediatek, Renesas, Tegra,
Qualcomm, Broadcom, NXP, ...)
There are also some separate subsystem with downstream maintainers
that merge updates this way:
- Various updates and new drivers in the memory controller subsystem
for Mediatek and Broadcom SoCs
- Small set of changes in preparation to add support for FF-A v1.1
specification later, in the Arm FF-A firmware subsystem
- debugfs support in the PSCI firmware subsystem"
* tag 'arm-drivers-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (149 commits)
ARM: remove check for CONFIG_DEBUG_LL_SER3
firmware/psci: Add debugfs support to ease debugging
firmware/psci: Print a warning if PSCI doesn't accept PC mode
dt-bindings: memory: snps,dw-umctl2-ddrc: Extend schema with IRQs/resets/clocks props
dt-bindings: memory: snps,dw-umctl2-ddrc: Replace opencoded numbers with macros
dt-bindings: memory: snps,dw-umctl2-ddrc: Use more descriptive device name
dt-bindings: memory: synopsys,ddrc-ecc: Detach Zynq DDRC controller support
soc: sunxi: sram: Add support for the D1 system control
soc: sunxi: sram: Export the LDO control register
soc: sunxi: sram: Save a pointer to the OF match data
soc: sunxi: sram: Return void from the release function
soc: apple: rtkit: Add apple_rtkit_poll
soc: imx: add i.MX93 media blk ctrl driver
soc: imx: add i.MX93 SRC power domain driver
soc: imx: imx8m-blk-ctrl: Use genpd_xlate_onecell
soc: imx: imx8mp-blk-ctrl: handle PCIe PHY resets
soc: imx: imx8m-blk-ctrl: add i.MX8MP VPU blk ctrl
soc: imx: add i.MX8MP HDMI blk ctrl HDCP/HRV_MWR
soc: imx: add icc paths for i.MX8MP hsio/hdmi blk ctrl
soc: imx: add icc paths for i.MX8MP media blk ctrl
...
Pin descriptions for this chip only look like standard GPIO device tree
descriptions, while in fact they contain additional data (in excess of
number of cells specified in description of gpio controllers). They also
refer to only pins/gpios belonging to the driver and not to arbitrary
gpio in the system.
Because we want to stop exporting OF-specific handlers from gpiolib-of,
let's parse the pin reference ourself instead of trying to call
of_get_named_gpio().
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/YzSsgoVoJn4+mSpv@google.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Before the split of gpio and pinctrl sections in their own driver,
rockchip_set_mux was called in pinmux_ops.gpio_set_direction for
configuring a pin in its GPIO function.
This is essential for cases where pinctrl is "bypassed" by gpio
consumers otherwise the GPIO function is not configured for the pin and
it does not work. Such was the case for the sysfs/libgpiod userspace
GPIO handling.
Let's re-implement the pinmux_ops.gpio_set_direction callback so that
the gpio subsystem can request from the pinctrl driver to put the pin in
its GPIO function.
Fixes: 9ce9a02039 ("pinctrl/rockchip: drop the gpio related codes")
Cc: stable@vger.kernel.org
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Link: https://lore.kernel.org/r/20220930132033.4003377-2-foss+kernel@0leil.net
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
On PREEMPT_RT enabled kernels the demultiplex interrupt handler is force
threaded and runs with interrupts enabled. The invocation of
generic_handle_domain_irq() with interrupts enabled triggers a lockdep
warning due to a non-irq safe lock acquisition.
Instead of disabling interrupts on the driver level, use
generic_handle_domain_irq_safe().
[ tglx: Split out from combo patch ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/YnkfWFzvusFFktSt@linutronix.de
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215954
Add support for SPMI PMIC GPIO subtypes GPIO_LV_VIN2 and
GPIO_MV_VIN3.
GPIO_LV_VIN2 GPIOs support two input reference voltages: VIN0 and
VIN1. These are typically connected to 1.8 V and 1.2 V supplies
respectively.
GPIO_MV_VIN3 GPIOs support three input reference voltages: VIN0,
VIN1, and VIN2. These are typically connected to Vph, 1.8 V, and
1.2 V supplies respectively.
Signed-off-by: David Collins <quic_collinsd@quicinc.com>
Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
Link: https://lore.kernel.org/r/20220912210624.4527-2-quic_amelende@quicinc.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Commit b6d09f7807 ("pinctrl: nomadik: Drop U8540/9540 support") removes
the DB8540 pin controller driver and its config PINCTRL_DB8540.
There is some code left-over in the generic nomadik pinctrl driver, i.e.,
drivers/pinctrl/nomadik/pinctrl-nomadik.{ch}, that is still around for the
removed DB8540 pin controller driver.
Remove this remaining dead code.
This issue was discovered with ./scripts/checkkconfigsymbols.py.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220919065435.27747-1-lukas.bulwahn@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
When an external device generated a level based interrupt then the
interrupt controller could miss the interrupt. The reason is that the
interrupt controller can detect only link changes.
In the following example, if there is a PHY that generates an interrupt
then the following would happen. The GPIO detected that the interrupt
line changed, and then the 'ocelot_irq_handler' was called. Here it
detects which GPIO line saw the change and for that will call the
following:
1. irq_mask
2. phy interrupt routine
3. irq_eoi
4. irq_unmask
And this works fine for simple cases, but if the PHY generates many
interrupts, for example when doing PTP timestamping, then the following
could happen. Again the function 'ocelot_irq_handler' will be called
and then from here the following could happen:
1. irq_mask
2. phy interrupt routine
3. irq_eoi
4. irq_unmask
Right before step 3(irq_eoi), the PHY will generate another interrupt.
Now the interrupt controller will acknowledge the change in the
interrupt line. So we miss the interrupt.
A solution will be to use 'handle_level_irq' instead of
'handle_fasteoi_irq', because for this will change routine order of
handling the interrupt.
1. irq_mask
2. irq_ack
3. phy interrupt routine
4. irq_unmask
And now if the PHY will generate a new interrupt before irq_unmask, the
interrupt controller will detect this because it already acknowledge the
change in interrupt line at step 2(irq_ack).
But this is not the full solution because there is another issue. In
case there are 2 PHYs that share the interrupt line. For example phy1
generates an interrupt, then the following can happen:
1.irq_mask
2.irq_ack
3.phy0 interrupt routine
4.phy1 interrupt routine
5.irq_unmask
In case phy0 will generate an interrupt while clearing the interrupt
source in phy1, then the interrupt line will be kept down by phy0. So
the interrupt controller will not see any changes in the interrupt line.
The solution here is to update 'irq_unmask' such that it can detect if
the interrupt line is still active or not. And if it is active then call
again the procedure to clear the interrupts. But we don't want to do it
every time, only if we know that the interrupt controller has not seen
already that the interrupt line has changed.
While at this, add support also for IRQ_TYPE_LEVEL_LOW.
Fixes: be36abb71d ("pinctrl: ocelot: add support for interrupt controller")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://lore.kernel.org/r/20220909145942.844102-1-horatiu.vultur@microchip.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Samsung pinctrl drivers changes for v6.1
1. Minor fix in order of initializing pinctrl driver - GPIOs should be
configured before registering gpiolib.
2. Final steps to deprecated bindings headers with register constants.
The constants were moved to include files in DTS directories, because
these are not suitable for bindings. Remove final references and
mark binding header as deprecated to warn any users.
