Refactor Raspberry Pi GPIO and add GPIO mock

Refactor Raspberry Pi GPIO and add GPIO mock

* Provide access to GPIO from the RaspberryPi class
* Move the RPi memory mapped GPIO implementation to the RPi package
* Add a simple GPIO mock class to the gpio package
* Update all the samples

I have tested all samples manually.

R=mit@google.com, sigurdm@google.com, wibling@google.com
BUG=

Committed: https://github.com/dart-lang/fletch/commit/2ca94db0117a85c981a8042b6ae735e4fd578e53

[mit, 2015-10-05 06:47:47]

On 2015/10/04 15:59:03, Søren Gjesse wrote:

Overall lgtm

I think we should change the blinky sample to use the new higher level functions
in OnBoardLED.

[Søren Gjesse, 2015-10-05 07:18:55]

Updated blinky to not use GPIO.

[sigurdm, 2015-10-05 07:22:18]

LGTM

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio.dart
File pkg/gpio/lib/gpio.dart (right):

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio.dart#...
pkg/gpio/lib/gpio.dart:150: SysfsGPIO([int pins = GPIO.defaultPins]):
super(pins) {
How come this changed from 54 to 50? Was the other value wrong?

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio_mock....
File pkg/gpio/lib/gpio_mock.dart (right):

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio_mock....
pkg/gpio/lib/gpio_mock.dart:10: Function _setPin;
Should these have a default "do nothing" value?
Maybe be a list of listeners?

[sigurdm, 2015-10-05 07:22:21]

LGTM

[mit, 2015-10-05 07:26:13]

https://codereview.chromium.org/1389573002/diff/20001/samples/raspberry_pi/ba...
File samples/raspberry_pi/basic/blinky.dart (right):

https://codereview.chromium.org/1389573002/diff/20001/samples/raspberry_pi/ba...
samples/raspberry_pi/basic/blinky.dart:25: gpio.setPin(led, true);
I think we should change this to use the new OnBoardLED class

https://codereview.chromium.org/1389573002/diff/60001/samples/raspberry_pi/ba...
File samples/raspberry_pi/basic/blinky.dart (right):

https://codereview.chromium.org/1389573002/diff/60001/samples/raspberry_pi/ba...
samples/raspberry_pi/basic/blinky.dart:14: const int led = 47;
Should remove this constant

[wibling, 2015-10-05 07:43:38]

lgtm

https://codereview.chromium.org/1389573002/diff/60001/pkg/gpio/lib/gpio_mock....
File pkg/gpio/lib/gpio_mock.dart (right):

https://codereview.chromium.org/1389573002/diff/60001/pkg/gpio/lib/gpio_mock....
pkg/gpio/lib/gpio_mock.dart:26: checkPinRange(pin);
NIT: You could enforce the mode on get/set pin, e.g. fail if getting an output
pin etc.

https://codereview.chromium.org/1389573002/diff/60001/pkg/raspberry_pi/lib/ra...
File pkg/raspberry_pi/lib/raspberry_pi.dart (right):

https://codereview.chromium.org/1389573002/diff/60001/pkg/raspberry_pi/lib/ra...
pkg/raspberry_pi/lib/raspberry_pi.dart:174: const int oRDWR = 02;  // O_RDWR
NIT: Shouldn't we keep these as O_RDWR to make it clear they are not variables?

https://codereview.chromium.org/1389573002/diff/60001/pkg/raspberry_pi/lib/ra...
pkg/raspberry_pi/lib/raspberry_pi.dart:187: const int protRead = 0x1;  //
PROT_READ.
Ditto.

https://codereview.chromium.org/1389573002/diff/60001/pkg/raspberry_pi/lib/ra...
pkg/raspberry_pi/lib/raspberry_pi.dart:219: checkPinRange(pin);
NIT: Could enforce mode and fail on mismatch.

https://codereview.chromium.org/1389573002/diff/60001/pkg/raspberry_pi/lib/ra...
pkg/raspberry_pi/lib/raspberry_pi.dart:220: // GPIO output set and output clear
registers each have 1 bits for 32 pins.
NIT: bits -> bit

https://codereview.chromium.org/1389573002/diff/60001/pkg/raspberry_pi/lib/ra...
pkg/raspberry_pi/lib/raspberry_pi.dart:232: // GPIO pin level registers each
have 1 bits for 32 pins.
NIT: bits -> bit

[Søren Gjesse, 2015-10-05 07:43:40]

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio.dart
File pkg/gpio/lib/gpio.dart (right):

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio.dart#...
pkg/gpio/lib/gpio.dart:150: SysfsGPIO([int pins = GPIO.defaultPins]):
super(pins) {
On 2015/10/05 07:22:18, sigurdm wrote:
> How come this changed from 54 to 50? Was the other value wrong?

The value 50 is a pretty arbitrary default. 54 is the number of pins on RPi, and
that moved to the RPi specific part.

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio_mock....
File pkg/gpio/lib/gpio_mock.dart (right):

https://codereview.chromium.org/1389573002/diff/20001/pkg/gpio/lib/gpio_mock....
pkg/gpio/lib/gpio_mock.dart:10: Function _setPin;
On 2015/10/05 07:22:18, sigurdm wrote:
> Should these have a default "do nothing" value?
> Maybe be a list of listeners?
> 

Let's iterate in this. In principle I agree that the default probably should be
do nothing.

https://codereview.chromium.org/1389573002/diff/20001/samples/raspberry_pi/ba...
File samples/raspberry_pi/basic/blinky.dart (right):

https://codereview.chromium.org/1389573002/diff/20001/samples/raspberry_pi/ba...
samples/raspberry_pi/basic/blinky.dart:25: gpio.setPin(led, true);
On 2015/10/05 07:26:13, mit wrote:
> I think we should change this to use the new OnBoardLED class

Done.

https://codereview.chromium.org/1389573002/diff/60001/samples/raspberry_pi/ba...
File samples/raspberry_pi/basic/blinky.dart (right):

https://codereview.chromium.org/1389573002/diff/60001/samples/raspberry_pi/ba...
samples/raspberry_pi/basic/blinky.dart:14: const int led = 47;
On 2015/10/05 07:26:13, mit wrote:
> Should remove this constant

Done.

[Søren Gjesse, 2015-10-05 07:44:09]

Committed patchset #5 (id:80001) manually as
2ca94db0117a85c981a8042b6ae735e4fd578e53 (presubmit successful).