On 04/03/2015 at 09:52:42 +0100, Philippe De Muyter wrote : > > > And is the naming in Philippe's driver appropriate? If it supports the > > > AB1801 (for example) then why is it described as an "abx805" driver? > > > > The real naming is in the form ABx8yz. With: > > > > x: 0 or 1, indicate the presence of the reset management > > y: 0 or 1: 0 is i2c, 1 is spi > > z: [1-5]: different amount of on chip SRAM. From what I understand, only > > ABx8y5 are actually recommended for new designs. > > My driver is based on the datashet called 'AB18X5 Real-Time Clock with > Power Management Family', which calls the parts 'AB18X5 family' with X > being '0' for I2c parts and '1' for SPI parts. > > As the part I have and the driver I wrote are I2C, not SPI, I fixed the > 'X' as 0 in the name of the driver. > > The datasheet lists only one part as being 'software and pin compatible' > with the 'AB1805': the 'AB0805', hence the 'x' in the name I choose : abx805. >
The "AB08XX Real-Time Clock Family" document states that they are all software and pin compatible (including the AB18xx). > Actually, my driver is used in production and works fine, because the > default(reset) value of the 12/24 mode bit is '24 hour mode' and the > default value of the 'write RTC bit' enables writing. There is > no real need to play with them. > I know this is unlikely to happen but what if someone messes with the RTC in the bootloader? > > > > What I like in Philippe's driver is the info printed at probe time and > > the support for trickle charging. However, I wouldn't enable it > > unconditionally. > > My hardware colleagues told me that the only way to enable the 'ultra > low-power' > functionality is enabling the trickle charger. And the 'ultra low-power' > functionality is the reason we choose that chip, so I would at least > keep that as the default behaviour. > My concern is that you have a static configuration. I would expose a sysfs interface to configure the diode, resistor and enable/disable the trickle charger. Would that work for you? -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
