Hi Mike, On Thu, Jan 24, 2013 at 03:10:53, Mike Turquette wrote: > Quoting Afzal Mohammed (2013-01-23 03:38:52) > > Some of clocks can have a limit on minimum divider value that can be > > programmed, prepare for such a support. > > Add a new field min_div for the basic divider clock and a new dynamic > > clock divider registration function where minimum divider value can > > be specified. Keep behaviour of existing divider clock registration > > functions, static initialization helpers as was earlier. > My first question is whether the minimum divider you plan to use is an > actual constraint of the hardware (e.g. the clock controller ip only > lets program two bits which divide by 4, 5, 6 or 7, where 4 is the > minimum divider) or if this is a functional constraint (e.g. the clock > hardware can divide by a lower value, but you never want that since it > results in non-functional video/audio/whatever). If this is more of a > functional constraint then perhaps a new api like clk_set_min_rate makes > more sense. It is a functional constraint: divider has 8 bits and it can have all possible values (0 to 255) and divider value corresponds to value set in the 8 bits. But depending on the modes the minimum value that can be configured (to get display working) varies. Eg. For raster mode (which the driver is presently supporting), it can take a minimum value of 2, while in LIDD (LCD interface display driver) mode it can take a min value of 1. Here min rate is not a constraint w.r.t divider in LCDC IP, but rather min divider. As it is the case, you prefer a clk_divider_set_min_div()? > > Secondly, have you looked into using the rate-table option provided by > the basic divider clock? Can you explain how this is not a good fit for > your needs? Perhaps there are too many divisor values so the table > would be large? Divider values can range from 2-255 (254 possible values), so I believe it is not a suitable candidate here (also divider to values have 1-to-1 mapping) Regards Afzal {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I