[PATCH v5 0/9] hw/misc/pca9552: Trace GPIO change events

[Philippe Mathieu-Daudé]

This series add trace events to better display GPIO changes.
We'll continue in the following series by connecting LEDs to
these GPIOs.

This helps me to work on a generic LED device, see:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg711917.html

Since v4: Addressed Cédric review comments
- Extract PCA955xClass
- Add/use pca955x_pins_get_status() method instead of keeping
  cached value in PCA955xState

Example when booting an obmc-phosphor-image, we can see the LED #14
(front-power LED) starting to blink.

- ASCII LED bar view:

  $ qemu-system-arm -M witherspoon-bmc -trace pca955x_gpio_status
  1592689902.327837:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[*...............]
  1592689902.329934:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[**..............]
  1592689902.330717:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[***.............]
  1592689902.331431:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****............]
  1592689902.332163:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........*..]
  1592689902.332888:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........**.]
  1592689902.333629:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........***]
  1592690032.793289:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........*.*]
  1592690033.303163:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........***]
  1592690033.812962:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........*.*]
  1592690034.323234:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........***]
  1592690034.832922:pca955x_gpio_status pca-unspecified GPIOs 0-15 
[****.........*.*]

- Only display GPIOs which status changes:

  $ qemu-system-arm -M witherspoon-bmc -trace pca955x_gpio_change
  1592690552.687372:pca955x_gpio_change pca1 GPIO id:0 status: 0 -> 1
  1592690552.690169:pca955x_gpio_change pca1 GPIO id:1 status: 0 -> 1
  1592690552.691673:pca955x_gpio_change pca1 GPIO id:2 status: 0 -> 1
  1592690552.696886:pca955x_gpio_change pca1 GPIO id:3 status: 0 -> 1
  1592690552.698614:pca955x_gpio_change pca1 GPIO id:13 status: 0 -> 1
  1592690552.699833:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1
  1592690552.700842:pca955x_gpio_change pca1 GPIO id:15 status: 0 -> 1
  1592690683.841921:pca955x_gpio_change pca1 GPIO id:14 status: 1 -> 0
  1592690683.861660:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1
  1592690684.371460:pca955x_gpio_change pca1 GPIO id:14 status: 1 -> 0
  1592690684.882115:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1
  1592690685.391411:pca955x_gpio_change pca1 GPIO id:14 status: 1 -> 0
  1592690685.901391:pca955x_gpio_change pca1 GPIO id:14 status: 0 -> 1

For information about how to test the obmc-phosphor-image, see:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg712911.html

$ git backport-diff -u v4
Key:
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/9:[----] [--] 'hw/i2c/core: Add i2c_try_create_slave() and 
i2c_realize_and_unref()'
002/9:[down] 'hw/misc/pca9552: Rename 'nr_leds' as 'pin_count''
003/9:[down] 'hw/misc/pca9552: Rename generic code as pca955x'
004/9:[down] 'hw/misc/pca9552: Add generic PCA955xClass, parent of TYPE_PCA9552'
005/9:[0007] [FC] 'hw/misc/pca9552: Add a 'description' property for debugging 
purpose'
006/9:[0031] [FC] 'hw/misc/pca9552: Trace GPIO High/Low events'
007/9:[----] [--] 'hw/arm/aspeed: Describe each PCA9552 device'
008/9:[0008] [FC] 'hw/misc/pca9552: Trace GPIO change events'
009/9:[0005] [FC] 'hw/misc/pca9552: Model qdev output GPIOs'

Based-on: <20200620162818.22340-1-f4bug@amsat.org>

Philippe Mathieu-Daudé (9):
  hw/i2c/core: Add i2c_try_create_slave() and i2c_realize_and_unref()
  hw/misc/pca9552: Rename 'nr_leds' as 'pin_count'
  hw/misc/pca9552: Rename generic code as pca955x
  hw/misc/pca9552: Add generic PCA955xClass, parent of TYPE_PCA9552
  hw/misc/pca9552: Add a 'description' property for debugging purpose
  hw/misc/pca9552: Trace GPIO High/Low events
  hw/arm/aspeed: Describe each PCA9552 device
  hw/misc/pca9552: Trace GPIO change events
  hw/misc/pca9552: Model qdev output GPIOs

 include/hw/i2c/i2c.h      |   2 +
 include/hw/misc/pca9552.h |  16 +--
 hw/arm/aspeed.c           |  13 ++-
 hw/i2c/core.c             |  18 +++-
 hw/misc/pca9552.c         | 216 ++++++++++++++++++++++++++++----------
 hw/misc/trace-events      |   4 +
 6 files changed, 202 insertions(+), 67 deletions(-)

-- 
2.21.3