> > On 8/16/19 10:40 PM, Li Yang wrote: > > On Fri, Aug 16, 2019 at 11:30 AM Alexandre Belloni > > <alexandre.belloni@xxxxxxxxxxx> wrote: > >> > >> On 16/08/2019 10:50:49-0500, Li Yang wrote: > >>> On Fri, Aug 16, 2019 at 3:05 AM Alexandre Belloni > >>> <alexandre.belloni@xxxxxxxxxxx> wrote: > >>>> > >>>> On 16/08/2019 10:46:36+0800, Biwen Li wrote: > >>>>> Issue: > >>>>> - # hwclock -w > >>>>> hwclock: RTC_SET_TIME: Invalid argument > >>>>> > >>>>> Why: > >>>>> - Relative patch: > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flkml.org > %2Flkml%2F2019%2F4%2F3%2F55&data=02%7C01%7Cbiwen.li%40nxp. > com%7Cff8cebc3f1034ae3fa9608d725ff9e5e%7C686ea1d3bc2b4c6fa92cd99 > c5c301635%7C0%7C0%7C637019652111923736&sdata=spY6e22YOkOF > 3%2BF7crSM0M6xPmOhgULDqMZLQw%2BAmdI%3D&reserved=0 , this > patch > >>>>> will always check for unwritable registers, it will compare reg > >>>>> with max_register in regmap_writeable. > >>>>> > >>>>> - In drivers/rtc/rtc-pcf85363.c, CTRL_STOP_EN is 0x2e, but > DT_100THS > >>>>> is 0, max_regiter is 0x2f, then reg will be equal to 0x30, > >>>>> '0x30 < 0x2f' is false,so regmap_writeable will return false. > >>>>> > >>>>> - Root cause: the buf[] was written to a wrong place in the file > >>>>> drivers/rtc/rtc-pcf85363.c > >>>>> > >>>> > >>>> This is not true, the RTC wraps the register accesses properly and > >>>> this > >>> > >>> This performance hack probably deserve some explanation in the code > >>> comment. :) > >>> > >>>> is probably something that should be handled by regmap_writable. > >>> > >>> The address wrapping is specific to this RTC chip. Is it also > >>> commonly used by other I2C devices? I'm not sure if regmap_writable > >>> should handle the wrapping case if it is too special. > >>> > >> > >> Most of the i2c RTCs do address wrapping which is sometimes the only > >> way to properly set the time. > > > > Adding Mark and Nandor to the loop. > > > > Regards, > > Leo > > > > Hi, > `regmap` provides couple of ways to validate the registers: > max_register, callback function and write table. All of these are optional, so it > gives you the freedom to customize it as needed. > > In this situation probably you could: > 1. Avoid using the wrapping feature of pcf85363 (you can just provide > separate calls for stop, reset and time confguration). In this way the > `max_register` validation method will work fine. Yes, I use this way. Path as follows: Stop and reset - > set time > stop > 2. Replace `max_register` method validation with `callback function` > validation method, were you could make your own validation. It is not work, show the code in as follows: bool regmap_writeable(struct regmap *map, unsigned int reg) { if (map->max_register && reg > map->max_register) return false; Callback function (writeable_reg) will not be called. if (map->writeable_reg) return map->writeable_reg(map->dev, reg); if (map->wr_table) return regmap_check_range_table(map, reg, map->wr_table); return true; } > > > Regards, > Nandor >
