Hi Bob,
thanks for reviewing.
On 2017-08-17 17:43, Rob Herring wrote:
On Fri, Aug 11, 2017 at 03:17:36PM +0200, Danilo Krummrich wrote:
This driver provides PS/2 serio bus support by implementing bit
banging
with the GPIO API. The GPIO pins, data and clock, can be configured
with
a node in the device tree or by generic device properties (GDP).
Writing to a device is supported as well, though it is possible
timings
can not be halt as they are tough and difficult to reach with bit
banging.
Therefore it can be configured (also in DT and GDP) whether the serio
write function should be available for clients.
This driver is for development purposes and not recommended for
productive
use. However, this driver can be useful e.g. when no USB port is
available
or using old peripherals is desired as PS/2 controller chips getting
rare.
This driver was tested on RPI1 and on Hikey960 and it worked well
together
with the atkbd and psmouse driver.
Signed-off-by: Danilo Krummrich <danilokrummrich@xxxxxxxxxxxxx>
---
v2: Removed one verbose print statement, changed another one to
dev_dbg.
v3: - fixed compiler warning on blackfin
- depends on GPIOLIB
- clarify documentation
v4: - fixed concurrent calls to ps2_gpio_write (serio->write)
- use gpiod API
- use generic device properties
- request irq separately, do not use gpiod_to_irq
- abort when gpio is connected via slow bus
- Fixed a bug where PS2_CMD_RESEND is always send after tx failed
once.
The makes the write functionallity work better, tough timing is
still
critical.
- disable irq initially until ps2_gpip_open (serio->open) is
called
v5: Checked again why timings are that hard to reach while in tx mode
and
discovered that there is an extra clock pulse between stop bit
sent from
host and acknowledgement from device. By just skipping this clock
pulse
tx works fine now, though it still happens sometimes that the
timing can
not be reached of course.
v6: - fixed typos
- use of_match_ptr
v7: remove unnecessary barriers
Sorry for resending, forgot der version tag in the subject.
---
.../devicetree/bindings/serio/ps2-gpio.txt | 22 +
It's preferred to split bindings to separate patch.
Together with Documentation/gpio/drivers-on-gpio.txt or would you prefer
to have
a separate patch for this as well?
Documentation/gpio/drivers-on-gpio.txt | 5 +
drivers/input/serio/Kconfig | 11 +
drivers/input/serio/Makefile | 1 +
drivers/input/serio/ps2-gpio.c | 453
+++++++++++++++++++++
5 files changed, 492 insertions(+)
create mode 100644
Documentation/devicetree/bindings/serio/ps2-gpio.txt
create mode 100644 drivers/input/serio/ps2-gpio.c
diff --git a/Documentation/devicetree/bindings/serio/ps2-gpio.txt
b/Documentation/devicetree/bindings/serio/ps2-gpio.txt
new file mode 100644
index 000000000000..099dd6d46cb3
--- /dev/null
+++ b/Documentation/devicetree/bindings/serio/ps2-gpio.txt
@@ -0,0 +1,22 @@
+Device-Tree bindings for ps/2 gpio driver
Bindings don't describe drivers.
Will fix.
+
+Required properties:
+ - compatible = "ps2-gpio"
+ - gpios: data and clock gpio
+ - interrupts: Should trigger on the falling edge of the clock line.
+
+Optional properties:
+ - ps2-gpio,write-enable: Indicates whether write function is
provided
ps2-gpio is not a vendor prefix, so drop it.
I will do.
+ to serio device. Possibly providing the write fn will not work,
because
+ of the tough timing requirements.
+
+Example nodes:
+
+ps2@0 {
+ compatible = "ps2-gpio";
+ interrupt-parent = <&gpio>;
+ interrupts = <23 IRQ_TYPE_EDGE_FALLING>;
+ data-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
+ clk-gpios = <&gpio 23 GPIO_ACTIVE_HIGH>;
+ ps2-gpio,write-enable;
+};
Thanks,
Danilo
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