On Mon, Jan 23, 2012 at 05:35:51PM -0500, Vivien Didelot wrote: > On Mon, 23 Jan 2012 15:54:08 -0500, > Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx> wrote: > > > On Sun, 22 Jan 2012 20:36:46 -0800, > > Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> wrote: > > > > > Regarding the location, I'd really like to know from the > > > > > powers-that-be if arch/x86/platform/ts5500/ > > > > > or > > > > > drivers/platform/x86 > > > > > or > > > > > drivers/hwmon > > > > > > > > > > would be the appropriate location for a driver like this. As > > > > > mentioned before, my strong preference is drivers/hwmon, but I > > > > > would like to hear from others. > > > > > > > > We should either split every driver into corresponding > > > > subdirectories, or put everything in a common platform directory. > > > > My first RFC patches set has every driver separated. As they are > > > > really specific to the platform, people seem to agree with > > > > grouping them, mainly because they won't be shared. I changed > > > > that in the following patches sets, and X86 maintainers seemed to > > > > be ok with that. > > > > > > > > I'm ok with both solutions, but we should all agree on one. > > > > Maybe we should have other maintainers view on this? > > > > > > > That is what I had asked for. I thought the whole point of > > > per-module directories was to have all drivers there. If that is no > > > longer true, fine with me; who am I to argue about something like > > > that. I'd just like to know. > > > > > > > > Also, I am not sure if the current approach is appropriate to > > > > > start with. Looking at the datasheet as well as into existing > > > > > kernel code, it appears quite likely that some kind of more or > > > > > less generic MAX197 driver exists somewhere. The existence of > > > > > is_max197_installed() - without any calling code - is a strong > > > > > indication that this is the case, as well as the "static" > > > > > platform data in your original patch. It might be more > > > > > appropriate to take this more or less generic driver, move it to > > > > > drivers/hwmon, and provide - for example through platform data - > > > > > a means to read from and write to the chip on a per-platform > > > > > basis, ie with per-platform access functions. > > > > > > > > You're right, it should be possible to create a generic max197 > > > > driver and provide read/write functions through platform data. But > > > > we don't have a max197 right now... So it can stay as a compact > > > > TS-5500 ADC driver for the moment, and maybe we will split later. > > > > What do you think? > > > > > > > I am lost. If you don't have a TS-5500 with max197, how do you test > > > the driver ? > > > > Sorry, I wasn't clear. I meant the only max197 I have is the one > > behind the TS-5500 CPLD, I don't have any others to test > > independently. > > > > > I had another look into the MAX197 and TS-5500 data sheets. In my > > > opinion, a generic MAX197 driver in drivers/hwmon combined with a > > > platform driver in the current location would be the way to go. That > > > driver would then also work for the other TS-5x00 systems. All you > > > need is a single chip access function in the platform code, since > > > the chip is always accessed with a write followed by a read. > > > > I took a deeper look at the datasheets, and you're right, a MAX197 > > driver seems to be a good choice. However, there are a number of > > differences between a direct usage of a MAX197 and the TS-5500 mapped > > MAX197. > > > > To start a conversion of a channel for a given range and polarity, it > > consists on both sides of a u8 outb() call on pins 7-14 (i.e. bits > > D7-D0). To be notified when the result is ready, we can either set an > > IRQ on INT pin (falling edge), or poll it. > > Then on the MAX197, you read the pins 7-14, set pin HBEN to 1, and > > read the same pins again to get the 4 remaining bits. On the TS-5500, > > only polling is available, and the 12 bits are mapped on 2 registers. > > > > I propose to write a max197 driver with default read and write > > functions. A platform_data will be used to specify the base address > > (pins 7-14), and eventually a custom read function pointer, which will > > be used instead of the default one if it is different of NULL. > > > > What do you think? > > > > I will write a max197 driver with default read and write functions. A > > platform_data will be used to specify the base address (pins 7-14), > > and eventually a custom read function pointer, which will be used > > instead of the default, if it is not NULL. > > > > What do you think? > Sounds like a plan to me. > Sorry for the duplicate :) > > BTW, I've added Jean Delvare and the lm-sensors mailing list in Cc, in > case they have an opinion on this. > Thanks, Guenter _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
