Add I2C statistics such as Bus Error counts and NACK counts as sysfs attributes. I2C statistics such as bus error counts and NACK counts, are implemented in many I2C controllers. Some drivers already populate the counters in debugfs. Having those statistics in sysfs can enable for a unified definition across various I2C drivers, make the statistics more ABI-stable. Overall the patch works in the following way: 1) A sysfs directory for I2C statistics is created for an i2c_adapter. 2) Each specific I2C driver can optionally instantiate each of the statistics individually. Test Process: 1. Clone the OpenBMC repository 2. `devtool modify`and apply patch to the linux-nuvoton recipe 3. Build image for quanta-gsj 4. Build QEMU 5. Run the image-bmc image in QEMU Results: root@gsj:/sys/class/i2c-adapter/i2c-1/stats# ls ber_cnt i2c_speed nack_cnt rec_fail_cnt rec_succ_cnt timeout_cnt root@gsj:/sys/class/i2c-adapter/i2c-1/stats# cat * 0 100000 0 0 0 0 Sui Chen (2): i2c debug counters as sysfs attributes add npcm7xx debug counters as sysfs attributes drivers/i2c/busses/i2c-npcm7xx.c | 8 +++ drivers/i2c/i2c-core-base.c | 2 + drivers/i2c/i2c-dev.c | 98 ++++++++++++++++++++++++++++++++ include/linux/i2c.h | 26 +++++++++ 4 files changed, 134 insertions(+) (Previously sent to linux-i2c, resending to linux-kernel with CCed correspondents) CC: OpenBMC Mailing List <openbmc@xxxxxxxxxxxxxxxx> CC: linux-i2c <linux-i2c@xxxxxxxxxxxxxxx> CC: linux-kernel <linux-kernel@xxxxxxxxxxxxxxx> CC: Joel Stanley <joel@xxxxxxxxx> CC: Andrew Jeffery <andrew@xxxxxxxx> CC: Tali Perry <tali.perry1@xxxxxxxxx> CC: Benjamin Fair <benjaminfair@xxxxxxxxxx> CC: Josh Lehan <krellan@xxxxxxxxxx> -- 2.34.0.rc0.344.g81b53c2807-goog
