Calling the disable_irq() from irq handler might be a bad idea as
disable_irq() should wait for handlers to run. I don't see why
this wouldn't deadlock in wait_event waiting for the threaded
handler to complete.
Use disable_irq_nosync() instead.
Fixes: 390af53e04 ("regulator: qcom-labibb: Implement short-circuit and over-current IRQs")
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Link: https://lore.kernel.org/r/f2c4c88d90bf7473e1b84b8a99b7b33d7a081764.1612249657.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Short-Circuit Protection (SCP) and Over-Current Protection (OCP) are
very important for regulators like LAB and IBB, which are designed to
provide from very small to relatively big amounts of current to the
device (normally, a display).
Now that this regulator supports both voltage setting and current
limiting in this driver, to me it looked like being somehow essential
to provide support for SCP and OCP, for two reasons:
1. SCP is a drastic measure to prevent damaging "more" hardware in
the worst situations, if any was damaged, preventing potentially
drastic issues;
2. OCP is a great way to protect the hardware that we're powering
through these regulators as if anything bad happens, the HW will
draw more current than expected: in this case, the OCP interrupt
will fire and the regulators will be immediately shut down,
preventing hardware damage in many cases.
Both interrupts were successfully tested in a "sort-of" controlled
manner, with the following methodology:
Short-Circuit Protection (SCP):
1. Set LAB/IBB to 4.6/-1.4V, current limit 200mA/50mA;
2. Connect a 10 KOhm resistor to LAB/IBB by poking the right traces
on a FxTec Pro1 smartphone for a very brief time (in short words,
"just a rapid touch with flying wires");
3. The Short-Circuit protection trips: IRQ raises, regulators get
cut. Recovery OK, test repeated without rebooting, OK.
Over-Current Protection (OCP):
1. Set LAB/IBB to the expected voltage to power up the display of
a Sony Xperia XZ Premium smartphone (Sharp LS055D1SX04), set
current limit to LAB 200mA, IBB 50mA (the values that this
display unit needs are 200/800mA);
2. Boot the kernel: OCP fires. Recovery never happens because
the selected current limit is too low, but that's expected.
Test OK.
3. Set LAB/IBB to the expected current limits for XZ Premium
(LAB 200mA, IBB 800mA), but lower than expected voltage,
specifically LAB 5.4V, IBB -5.6V (instead of 5.6, -5.8V);
4. Boot the kernel: OCP fires. Recovery never happens because
the selected voltage (still in the working range limits)
is producing a current draw of more than 200mA on LAB.
Test OK.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Link: https://lore.kernel.org/r/20210119174421.226541-6-angelogioacchino.delregno@somainline.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Soft start is required to avoid inrush current during LAB ramp-up and
IBB ramp-down, protecting connected hardware to which we supply voltage.
Since soft start is configurable on both LAB and IBB regulators, it
was necessary to add two DT properties, respectively "qcom,soft-start-us"
to control LAB ramp-up and "qcom,discharge-resistor-kohms" to control
the discharge resistor for IBB ramp-down, which obviously brought the
need of implementing a of_parse callback for both regulators.
Finally, also implement pull-down mode in order to avoid unpredictable
behavior when the regulators are disabled (random voltage spikes etc).
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210119174421.226541-4-angelogioacchino.delregno@somainline.org
Signed-off-by: Mark Brown <broonie@kernel.org>
LAB and IBB regulators can be current-limited by setting the
appropriate registers, but this operation is granted only after
sending an unlock code for secure access.
Besides the secure access, it would be possible to use the
regmap helper for get_current_limit, as there is no security
blocking reads, but I chose not to as to avoid having a very
big array containing current limits, especially for IBB.
That said, these regulators support current limiting for:
- LAB (pos): 200-1600mA, with 200mA per step (8 steps),
- IBB (neg): 0-1550mA, with 50mA per step (32 steps).
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Link: https://lore.kernel.org/r/20210119174421.226541-3-angelogioacchino.delregno@somainline.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The LAB and IBB regulator have just one range and it is useless
to use linear_range ops, as these are used to express multiple
linear ranges.
Switch list_voltage and map_voltage callbacks to *_linear instead.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Link: https://lore.kernel.org/r/20210119174421.226541-2-angelogioacchino.delregno@somainline.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Implement {get,set}_voltage_sel, list_voltage, map_voltage with
the useful regulator regmap helpers in order to be able to manage
the voltage of LAB (positive) and IBB (negative) regulators.
In particular, the supported ranges are the following:
- LAB (pos): 4600mV to 6100mV with 100mV stepping,
- IBB (neg): -7700mV to -1400mV with 100mV stepping.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210113194214.522238-2-angelogioacchino.delregno@somainline.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The only usage of qcom_labibb_ops is to assign it to the ops field in
the regulator_desc struct, which is a const pointer. The only usage of
pmi8998_lab_desc and pmi8998_ibb_desc is to assign their address to the
desc field in the labibb_regulator_data struct which can be made const,
since it is only copied into the desc field in the
labbibb_regulator_data struct. This struct is modified, but that's a
copy of the static one. Make them const to allow the compiler to put
them in read-only memory.
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200930162602.18583-1-rikard.falkeborn@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Qualcomm platforms have LAB(LCD AMOLED Boost)/IBB(Inverting Buck Boost)
regulators, labibb for short, which are used as power supply for
LCD Mode displays.
This patch adds labibb regulator driver for pmi8998 PMIC, found on
SDM845 platforms.
[sumits: reworked the driver design as per upstream review]
Signed-off-by: Nisha Kumari <nishakumari@codeaurora.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://lore.kernel.org/r/20200622124110.20971-5-sumit.semwal@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Matti Vaittinen