linux-yocto/include/linux/platform_data
Nick Crews 14e14aaf61 platform/chrome: wilco_ec: Standardize mailbox interface
The current API for the wilco EC mailbox interface is bad.

It assumes that most messages sent to the EC follow a similar structure,
with a command byte in MBOX[0], followed by a junk byte, followed by
actual data. This doesn't happen in several cases, such as setting the
RTC time, using the raw debugfs interface, and reading or writing
properties such as the Peak Shift policy (this last to be submitted soon).

Similarly for the response message from the EC, the current interface
assumes that the first byte of data is always 0, and the second byte
is unused. However, in both setting and getting the RTC time, in the
debugfs interface, and for reading and writing properties, this isn't
true.

The current way to resolve this is to use WILCO_EC_FLAG_RAW* flags to
specify when and when not to skip these initial bytes in the sent and
received message. They are confusing and used so much that they are
normal, and not exceptions. In addition, the first byte of
response in the debugfs interface is still always skipped, which is
weird, since this raw interface should be giving the entire result.

Additionally, sent messages assume the first byte is a command, and so
struct wilco_ec_message contains the "command" field. In setting or
getting properties however, the first byte is not a command, and so this
field has to be filled with a byte that isn't actually a command. This
is again inconsistent.

wilco_ec_message contains a result field as well, copied from
wilco_ec_response->result. The message result field should be removed:
if the message fails, the cause is already logged, and the callers are
alerted. They will never care about the actual state of the result flag.

These flags and different cases make the wilco_ec_transfer() function,
used in wilco_ec_mailbox(), really gross, dealing with a bunch of
different cases. It's difficult to figure out what it is doing.

Finally, making these assumptions about the structure of a message make
it so that the messages do not correspond well with the specification
for the EC's mailbox interface. For instance, this interface
specification may say that MBOX[9] in the received message contains
some information, but the calling code needs to remember that the first
byte of response is always skipped, and because it didn't set the
RESPONSE_RAW flag, the next byte is also skipped, so this information
is actually contained within wilco_ec_message->response_data[7]. This
makes it difficult to maintain this code in the future.

To fix these problems this patch standardizes the mailbox interface by:
- Removing the WILCO_EC_FLAG_RAW* flags
- Removing the command and reserved_raw bytes from wilco_ec_request
- Removing the mbox0 byte from wilco_ec_response
- Simplifying wilco_ec_transfer() because of these changes
- Gives the callers of wilco_ec_mailbox() the responsibility of exactly
  and consistently defining the structure of the mailbox request and
  response
- Removing command and result from wilco_ec_message.

This results in the reduction of total code, and makes it much more
maintainable and understandable.

Signed-off-by: Nick Crews <ncrews@chromium.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2019-04-15 16:07:42 +02:00
..
gpio gpio: AMD G-Series PCH gpio driver 2019-02-22 17:26:52 +01:00
jz4740 MIPS: jz4740: Move jz4740_nand.h header to include/linux/platform_data/jz4740 2018-07-18 10:10:23 +02:00
media media: include: fix several typos 2019-03-01 09:45:52 -05:00
txx9 MIPS: txx9: Move the ndfc.h header to include/linux/platform_data/txx9 2018-07-18 10:10:23 +02:00
x86 clk: x86: Move clk-lpss.h to platform_data/x86 2019-02-22 00:14:31 -08:00
ad5449.h
ad5755.h
ad5761.h
ad7266.h
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adau17x1.h
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adp5588.h
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adp8870.h
ads1015.h
ads7828.h
ams-delta-fiq.h Input: ams_delta_serio: Get FIQ buffer from platform_data 2018-07-02 23:05:14 -07:00
apds990x.h
arm-ux500-pm.h
asoc-imx-ssi.h
asoc-kirkwood.h
asoc-mx27vis.h
asoc-palm27x.h
asoc-s3c.h
asoc-s3c24xx_simtec.h
asoc-ti-mcbsp.h
asoc-ux500-msp.h
at91_adc.h
ata-pxa.h
ata-samsung_cf.h
atmel.h
b53.h net: dsa: Include platform_data header file 2019-01-17 11:31:24 -08:00
bcmgenet.h
bd6107.h
bh1770glc.h
brcmfmac.h
clk-da8xx-cfgchip.h
clk-davinci-pll.h
clk-integrator.h
clk-st.h clk: x86: Add ST oscout platform clock 2018-05-17 12:44:06 +02:00
clk-u300.h
cpuidle-exynos.h
crypto-atmel.h
crypto-ux500.h
cyttsp4.h
davinci_asp.h ASoC: davinci-mcasp: Implement configurable dismod handling 2018-11-28 12:41:31 +00:00
davinci-cpufreq.h cpufreq: davinci: move configuration to include/linux/platform_data 2019-02-18 11:58:08 +05:30
db8500_thermal.h
dma-atmel.h
dma-coh901318.h
dma-dw.h dmaengine: dw: convert to SPDX identifiers 2019-01-07 17:57:13 +05:30
dma-ep93xx.h dmaengine: ep93xx: Return proper enum in ep93xx_dma_chan_direction 2018-10-02 20:11:00 +05:30
dma-hsu.h
dma-imx-sdma.h
dma-imx.h dmaengine: imx-sdma: add a test for imx8mq multi sdma devices 2019-02-25 23:25:51 +05:30
dma-mcf-edma.h dmaengine: fsl-edma: add ColdFire mcf5441x edma support 2018-09-11 12:06:39 +05:30
dma-mmp_tdma.h
dma-mv_xor.h
dma-s3c24xx.h
dma-ste-dma40.h
dmtimer-omap.h
ds620.h
dsa.h net: dsa: Split platform data to header file 2019-01-17 11:31:24 -08:00
dwc3-omap.h
edma.h
efm32-spi.h
efm32-uart.h
ehci-sh.h usb: ehci-sh: convert to SPDX identifiers 2018-09-10 19:58:49 +02:00
elm.h
emif_plat.h
eth-netx.h
fsa9480.h
g762.h
gpio_backlight.h
gpio-ath79.h
gpio-davinci.h gpio: davinci: restore a way to manually specify the GPIO base 2018-11-26 16:45:10 +05:30
gpio-dwapb.h gpio: dwapb: Fix rework support for 1 interrupt per port A GPIO 2018-05-28 09:45:27 +02:00
gpio-htc-egpio.h
gpio-omap.h ARM: SoC platform updates for 4.20 2018-10-29 15:37:33 -07:00
gpmc-omap.h
hsmmc-omap.h mmc: omap_hsmmc: Delete platform data GPIO CD and WP 2018-10-08 11:40:43 +02:00
hwmon-s3c.h
i2c-davinci.h
i2c-designware.h
i2c-gpio.h i2c: gpio: move header to platform_data 2018-05-17 16:27:09 +02:00
i2c-hid.h HID: i2c-hid: Add vddl regulator control 2018-06-25 15:12:42 +02:00
i2c-imx.h
i2c-mux-gpio.h i2c: mux: gpio: move header to platform_data 2018-05-17 16:27:52 +02:00
i2c-mux-reg.h
i2c-ocores.h i2c: ocores: Add support for bus clock via platform data 2019-02-14 17:58:23 +01:00
i2c-omap.h i2c: omap: move header to platform_data 2018-05-17 16:27:58 +02:00
i2c-pca-platform.h i2c: pca-platform: move header to platform_data 2018-05-17 16:27:58 +02:00
i2c-pxa.h
i2c-s3c2410.h
i2c-xiic.h i2c: xiic: move header to platform_data 2018-05-17 16:27:59 +02:00
ina2xx.h hwmon: (ina2xx) fix sysfs shunt resistor read access 2018-08-26 17:45:25 -07:00
intel-mid_wdt.h
intel-spi.h
invensense_mpu6050.h
iommu-omap.h
irda-pxaficp.h
irda-sa11x0.h
isl9305.h
itco_wdt.h
keyboard-pxa930_rotary.h
keyboard-spear.h
keypad-ep93xx.h
keypad-nomadik-ske.h
keypad-omap.h
keypad-pxa27x.h
keypad-w90p910.h
keyscan-davinci.h
lcd-mipid.h
leds-kirkwood-netxbig.h
leds-kirkwood-ns2.h
leds-lm355x.h
leds-lm3642.h
leds-lp55xx.h
leds-omap.h
leds-pca963x.h
leds-s3c24xx.h
lm3630a_bl.h
lm3639_bl.h
lm8323.h
lp855x.h
lp8727.h
lp8755.h
ltc4245.h
lv5207lp.h
macb.h
max197.h
max732x.h
max3421-hcd.h
max6639.h
max6697.h
mcs.h
mdio-bcm-unimac.h
mdio-gpio.h net: phy: mdio-gpio: Add phy_ignore_ta_mask to platform data 2018-12-08 21:33:30 -08:00
mfd-mcp-sa11x0.h
microchip-ksz.h
mlxreg.h linux-watchdog 5.1-rc1 tag 2019-03-11 11:22:15 -07:00
mmc-davinci.h
mmc-esdhc-imx.h mmc: sdhci: imx: Use the slot GPIO descriptor 2018-12-17 08:26:24 +01:00
mmc-mxcmmc.h
mmc-omap.h
mmc-pxamci.h mmc: pxa: Use GPIO descriptor for power 2018-12-17 08:26:24 +01:00
mmc-s3cmci.h mmc: s3cmci: Use the slot GPIO descriptor 2018-12-17 08:26:24 +01:00
mmc-sdhci-s3c.h
mmp_audio.h
mmp_dma.h dmaengine: pxa: use a dma slave map 2018-06-18 21:28:44 +02:00
mouse-pxa930_trkball.h
mtd-davinci-aemif.h ARM: davinci: unduplicate aemif support 2018-07-10 15:39:27 +05:30
mtd-davinci.h mtd: rawnand: davinci: store the core chipselect number in platform data 2018-05-02 14:58:30 +05:30
mtd-mxc_nand.h
mtd-nand-omap2.h
mtd-nand-pxa3xx.h
mtd-nand-s3c2410.h
mtd-orion_nand.h mtd: rawnand: orion_nand: Kill orion_nand_data.dev_ready() 2018-07-18 10:10:12 +02:00
mv_usb.h USB: EHCI: ehci-mv: remove private_init 2018-09-20 13:07:55 +02:00
mv88e6xxx.h net: dsa: Include platform_data header file 2019-01-17 11:31:24 -08:00
net-cw1200.h
nfcmrvl.h
ntc_thermistor.h hwmon: (ntc_thermistor) use a table to lookup the thermistor type 2018-12-16 15:13:21 -08:00
nxp-nci.h
omap-twl4030.h
omap-wd-timer.h
omap1_bl.h
omapdss.h
pca953x.h
pca954x.h
pcf857x.h
pcmcia-pxa2xx_viper.h
phy-da8xx-usb.h
pinctrl-single.h
pixcir_i2c_ts.h
pm33xx.h ARM: OMAP2+: sleep33/43xx: Add RTC-Mode support 2018-07-09 23:01:34 -07:00
pwm_omap_dmtimer.h
pxa_sdhci.h mmc: sdhci: pxav3: Delete GPIO handling 2018-10-08 11:40:43 +02:00
pxa2xx_udc.h
regulator-haptic.h
remoteproc-omap.h
rtc-ds2404.h
rtc-v3020.h
s3c-hsotg.h
s3c-hsudc.h
sa11x0-serial.h
sc18is602.h fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
sdhci-pic32.h
serial-imx.h
serial-omap.h
serial-sccnxp.h
shmob_drm.h drm: shmobile: convert to SPDX identifiers 2018-09-14 13:54:02 +03:00
sht3x.h
shtc1.h
si5351.h
simplefb.h
sky81452-backlight.h
spi-ath79.h spi: ath79: Enable support for compile test 2019-01-17 12:34:47 +00:00
spi-clps711x.h
spi-davinci.h spi: davinci: Remove chip select GPIO pdata 2018-09-11 17:37:15 +01:00
spi-ep93xx.h
spi-imx.h ARM: imx: Update spi_imx platform data to reflect current state 2018-04-18 11:11:23 +08:00
spi-mt65xx.h
spi-nuc900.h
spi-omap2-mcspi.h
spi-s3c64xx.h
ssm2518.h
st_sensors_pdata.h iio: imu: st_lsm6dsx: add i2c embedded controller support 2018-11-16 18:32:33 +00:00
st33zp24.h
syscon.h
tc35876x.h
tda9950.h drm/i2c: tda9950: add CEC driver 2018-04-24 10:44:25 +01:00
ti-aemif.h memory: aemif: add support for board files 2018-04-20 10:14:27 -07:00
ti-sysc.h bus: ti-sysc: Defer suspend as needed 2018-09-24 12:16:54 -07:00
touchscreen-s3c2410.h
tsc2007.h
tsl2563.h
tsl2772.h staging: iio: tsl2x7x/tsl2772: move out of staging 2018-05-12 12:40:04 +01:00
uio_dmem_genirq.h
uio_pruss.h
usb-davinci.h usb: ohci-da8xx: remove unused callbacks from platform data 2019-02-12 13:48:59 +05:30
usb-ehci-mxc.h
usb-ehci-orion.h
usb-musb-ux500.h
usb-mx2.h
usb-ohci-pxa27x.h
usb-ohci-s3c2410.h
usb-omap.h
usb-omap1.h
usb-pxa3xx-ulpi.h
usb-s3c2410_udc.h
usb3503.h
ux500_wdt.h
video_s3c.h
video-clcd-versatile.h
video-ep93xx.h
video-imxfb.h
video-mx3fb.h
video-nuc900fb.h
video-pxafb.h
voltage-omap.h
wilco-ec.h platform/chrome: wilco_ec: Standardize mailbox interface 2019-04-15 16:07:42 +02:00
wiznet.h
wkup_m3.h
zforce_ts.h