| Message ID | 4b05448b65969f9f433f7ac3aa234c33025ad262.1732811829.git.mazziesaccount@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iio: gts: Simplify available scales building | expand |
On Thu, 28 Nov 2024 18:51:00 +0200 Matti Vaittinen <mazziesaccount@gmail.com> wrote: > The GTS helpers offer two different set of "available scales" -tables. > Drivers can choose to advertice the scales which are available on a > currently selected integration time (by just changing the hwgain). > Another option is to list all scales which can be supported using any of > the integration times. This is useful for drivers which allow scale > setting to also change the integration time to meet the scale user > prefers. > > The helper function which build these tables for the GTS did firstbuild The helper function which builds these tables for the GTS first builds the "time specific" .. > the "time specific" scale arrays for all the times. This is done by > calculating the scales based on the integration time specific "total > gain" arrays (gain contributed by both the integration time and hw-gain). > > After this the helper code calculates an array for all available scales. > This is done combining all the time specific total-gains into one sorted > array, removing dublicate gains and finally converting the gains to > scales as above. > > This can be somewhat simplified by changing the logic for calculating > the 'all available scales' -array to directly use the time specific > scale arrays instead of time specific total-gain arrays. Code can > directly just add all the already computed time specific scales to one > big 'all scales'-array, keep it sorted and remove duplicates. > > Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> > Minor comments inline. Thanks, Jonathan > --- > > This has been tested by IIO-gts kunit tests only. All testing is > appreciated. > > Comparing the scales is not as pretty as comparing the gains was, as > scales are in two ints where the gains were in one. This makes the code > slightly more hairy. I however believe that the logic is now more > obvious. This might be more important for one reading this later... > --- > drivers/iio/industrialio-gts-helper.c | 109 ++++++++++---------------- > 1 file changed, 42 insertions(+), 67 deletions(-) > > diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c > index 7f900f578f1d..31101848b194 100644 > --- a/drivers/iio/industrialio-gts-helper.c > +++ b/drivers/iio/industrialio-gts-helper.c > @@ -191,86 +191,61 @@ static int fill_and_sort_scaletables(struct iio_gts *gts, int **gains, int **sca > return 0; > } > > -static int combine_gain_tables(struct iio_gts *gts, int **gains, > - int *all_gains, size_t gain_bytes) > +static int scale_eq(int *sc1, int *sc2) > { > - int i, new_idx, time_idx; > + return *sc1 == *sc2 && *(sc1 + 1) == *(sc2 + 1); return sc1[0] == sc2[0] && sc1[1] == sc2[1]; Would be easier to read in my opinion. > +} > > - /* > - * We assume all the gains for same integration time were unique. > - * It is likely the first time table had greatest time multiplier as > - * the times are in the order of preference and greater times are > - * usually preferred. Hence we start from the last table which is likely > - * to have the smallest total gains. > - */ > - time_idx = gts->num_itime - 1; > - memcpy(all_gains, gains[time_idx], gain_bytes); > - new_idx = gts->num_hwgain; > +static int scale_smaller(int *sc1, int *sc2) > +{ > + if (*sc1 != *sc2) > + return *sc1 < *sc2; > + > + /* If integer parts are equal, fixp parts */ > + return *(sc1 + 1) < *(sc2 + 1); > +} > + > +static int do_combined_scaletable(struct iio_gts *gts, int **scales, size_t scale_bytes) > +{ > + int t_idx, i, new_idx; > + int *all_scales = kcalloc(gts->num_itime, scale_bytes, GFP_KERNEL); > > - while (time_idx-- > 0) { > - for (i = 0; i < gts->num_hwgain; i++) { > - int candidate = gains[time_idx][i]; > + if (!all_scales) > + return -ENOMEM; > + > + t_idx = gts->num_itime - 1; > + memcpy(all_scales, scales[t_idx], scale_bytes); > + new_idx = gts->num_hwgain * 2; > + > + while (t_idx-- > 0) { maybe a reverse for loop is clearer for (tidx = t_idx; tidx; tidx--) For me a for loop indicates bounds are known and we change the index one per loop. While loop indicates either unknown bounds, or that we are modifying the index other than than in the loop controls. > + for (i = 0; i < gts->num_hwgain ; i++) { Extra space after hwgain > + int *candidate = &scales[t_idx][i * 2]; > int chk; > > - if (candidate > all_gains[new_idx - 1]) { > - all_gains[new_idx] = candidate; > - new_idx++; > + if (scale_smaller(candidate, &all_scales[new_idx - 2])) { > + all_scales[new_idx] = *candidate; Maybe candidate[0] and candidate[1] will be more readable as it's effectively a row of of 2D matrix. > + all_scales[new_idx + 1] = *(candidate + 1); > + new_idx += 2; > > continue; > } > - for (chk = 0; chk < new_idx; chk++) > - if (candidate <= all_gains[chk]) > + for (chk = 0; chk < new_idx; chk += 2) > + if (!scale_smaller(candidate, &all_scales[chk])) > break; > > - if (candidate == all_gains[chk]) > + > + if (scale_eq(candidate, &all_scales[chk])) > continue; > > - memmove(&all_gains[chk + 1], &all_gains[chk], > + memmove(&all_scales[chk + 2], &all_scales[chk], > (new_idx - chk) * sizeof(int)); > - all_gains[chk] = candidate; > - new_idx++; > + all_scales[chk] = *candidate; As above. Maybe treat as a 2 element array. > + all_scales[chk + 1] = *(candidate + 1); > + new_idx += 2; > } > }
On 30/11/2024 20:01, Jonathan Cameron wrote: > On Thu, 28 Nov 2024 18:51:00 +0200 > Matti Vaittinen <mazziesaccount@gmail.com> wrote: > >> The GTS helpers offer two different set of "available scales" -tables. >> Drivers can choose to advertice the scales which are available on a >> currently selected integration time (by just changing the hwgain). >> Another option is to list all scales which can be supported using any of >> the integration times. This is useful for drivers which allow scale >> setting to also change the integration time to meet the scale user >> prefers. >> >> The helper function which build these tables for the GTS did firstbuild > The helper function which builds these tables for the GTS first builds the "time specific" .. > >> the "time specific" scale arrays for all the times. This is done by >> calculating the scales based on the integration time specific "total >> gain" arrays (gain contributed by both the integration time and hw-gain). >> >> After this the helper code calculates an array for all available scales. >> This is done combining all the time specific total-gains into one sorted >> array, removing dublicate gains and finally converting the gains to >> scales as above. >> >> This can be somewhat simplified by changing the logic for calculating >> the 'all available scales' -array to directly use the time specific >> scale arrays instead of time specific total-gain arrays. Code can >> directly just add all the already computed time specific scales to one >> big 'all scales'-array, keep it sorted and remove duplicates. >> >> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> >> > Minor comments inline. > > Thanks, > > Jonathan > >> --- >> >> This has been tested by IIO-gts kunit tests only. All testing is >> appreciated. >> >> Comparing the scales is not as pretty as comparing the gains was, as >> scales are in two ints where the gains were in one. This makes the code >> slightly more hairy. I however believe that the logic is now more >> obvious. This might be more important for one reading this later... >> --- >> drivers/iio/industrialio-gts-helper.c | 109 ++++++++++---------------- >> 1 file changed, 42 insertions(+), 67 deletions(-) >> >> diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c >> index 7f900f578f1d..31101848b194 100644 >> --- a/drivers/iio/industrialio-gts-helper.c >> +++ b/drivers/iio/industrialio-gts-helper.c >> @@ -191,86 +191,61 @@ static int fill_and_sort_scaletables(struct iio_gts *gts, int **gains, int **sca >> return 0; >> } >> >> -static int combine_gain_tables(struct iio_gts *gts, int **gains, >> - int *all_gains, size_t gain_bytes) >> +static int scale_eq(int *sc1, int *sc2) >> { >> - int i, new_idx, time_idx; >> + return *sc1 == *sc2 && *(sc1 + 1) == *(sc2 + 1); > return sc1[0] == sc2[0] && sc1[1] == sc2[1]; > > Would be easier to read in my opinion. I agree. (As with the other (ptr + 1) cases you commented) >> +} >> >> - /* >> - * We assume all the gains for same integration time were unique. >> - * It is likely the first time table had greatest time multiplier as >> - * the times are in the order of preference and greater times are >> - * usually preferred. Hence we start from the last table which is likely >> - * to have the smallest total gains. >> - */ >> - time_idx = gts->num_itime - 1; >> - memcpy(all_gains, gains[time_idx], gain_bytes); >> - new_idx = gts->num_hwgain; >> +static int scale_smaller(int *sc1, int *sc2) >> +{ >> + if (*sc1 != *sc2) >> + return *sc1 < *sc2; >> + >> + /* If integer parts are equal, fixp parts */ >> + return *(sc1 + 1) < *(sc2 + 1); >> +} >> + >> +static int do_combined_scaletable(struct iio_gts *gts, int **scales, size_t scale_bytes) >> +{ >> + int t_idx, i, new_idx; >> + int *all_scales = kcalloc(gts->num_itime, scale_bytes, GFP_KERNEL); >> >> - while (time_idx-- > 0) { >> - for (i = 0; i < gts->num_hwgain; i++) { >> - int candidate = gains[time_idx][i]; >> + if (!all_scales) >> + return -ENOMEM; >> + >> + t_idx = gts->num_itime - 1; >> + memcpy(all_scales, scales[t_idx], scale_bytes); >> + new_idx = gts->num_hwgain * 2; >> + >> + while (t_idx-- > 0) { > maybe a reverse for loop is clearer > > for (tidx = t_idx; tidx; tidx--) > For me a for loop indicates bounds are known and we change the index > one per loop. I could've said that :) > While loop indicates either unknown bounds, or that we are > modifying the index other than than in the loop controls. I'm not entirely sure why I've used while here, could be a result of some review discussion. I'll fix these for the next version. Yours, -- Matti
diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c index 7f900f578f1d..31101848b194 100644 --- a/drivers/iio/industrialio-gts-helper.c +++ b/drivers/iio/industrialio-gts-helper.c @@ -191,86 +191,61 @@ static int fill_and_sort_scaletables(struct iio_gts *gts, int **gains, int **sca return 0; } -static int combine_gain_tables(struct iio_gts *gts, int **gains, - int *all_gains, size_t gain_bytes) +static int scale_eq(int *sc1, int *sc2) { - int i, new_idx, time_idx; + return *sc1 == *sc2 && *(sc1 + 1) == *(sc2 + 1); +} - /* - * We assume all the gains for same integration time were unique. - * It is likely the first time table had greatest time multiplier as - * the times are in the order of preference and greater times are - * usually preferred. Hence we start from the last table which is likely - * to have the smallest total gains. - */ - time_idx = gts->num_itime - 1; - memcpy(all_gains, gains[time_idx], gain_bytes); - new_idx = gts->num_hwgain; +static int scale_smaller(int *sc1, int *sc2) +{ + if (*sc1 != *sc2) + return *sc1 < *sc2; + + /* If integer parts are equal, fixp parts */ + return *(sc1 + 1) < *(sc2 + 1); +} + +static int do_combined_scaletable(struct iio_gts *gts, int **scales, size_t scale_bytes) +{ + int t_idx, i, new_idx; + int *all_scales = kcalloc(gts->num_itime, scale_bytes, GFP_KERNEL); - while (time_idx-- > 0) { - for (i = 0; i < gts->num_hwgain; i++) { - int candidate = gains[time_idx][i]; + if (!all_scales) + return -ENOMEM; + + t_idx = gts->num_itime - 1; + memcpy(all_scales, scales[t_idx], scale_bytes); + new_idx = gts->num_hwgain * 2; + + while (t_idx-- > 0) { + for (i = 0; i < gts->num_hwgain ; i++) { + int *candidate = &scales[t_idx][i * 2]; int chk; - if (candidate > all_gains[new_idx - 1]) { - all_gains[new_idx] = candidate; - new_idx++; + if (scale_smaller(candidate, &all_scales[new_idx - 2])) { + all_scales[new_idx] = *candidate; + all_scales[new_idx + 1] = *(candidate + 1); + new_idx += 2; continue; } - for (chk = 0; chk < new_idx; chk++) - if (candidate <= all_gains[chk]) + for (chk = 0; chk < new_idx; chk += 2) + if (!scale_smaller(candidate, &all_scales[chk])) break; - if (candidate == all_gains[chk]) + + if (scale_eq(candidate, &all_scales[chk])) continue; - memmove(&all_gains[chk + 1], &all_gains[chk], + memmove(&all_scales[chk + 2], &all_scales[chk], (new_idx - chk) * sizeof(int)); - all_gains[chk] = candidate; - new_idx++; + all_scales[chk] = *candidate; + all_scales[chk + 1] = *(candidate + 1); + new_idx += 2; } } - return new_idx; -} - -static int *build_all_scales_table(struct iio_gts *gts, int *all_gains, int num_scales) -{ - int i, ret; - int *all_scales __free(kfree) = kcalloc(num_scales, 2 * sizeof(int), - GFP_KERNEL); - - if (!all_scales) - return ERR_PTR(-ENOMEM); - - for (i = 0; i < num_scales; i++) { - ret = iio_gts_total_gain_to_scale(gts, all_gains[i], &all_scales[i * 2], - &all_scales[i * 2 + 1]); - if (ret) - return ERR_PTR(ret); - } - - return_ptr(all_scales); -} - -static int build_combined_tables(struct iio_gts *gts, - int **gains, size_t gain_bytes) -{ - int *all_scales, num_gains; - int *all_gains __free(kfree) = kcalloc(gts->num_itime, gain_bytes, - GFP_KERNEL); - - if (!all_gains) - return -ENOMEM; - - num_gains = combine_gain_tables(gts, gains, all_gains, gain_bytes); - - all_scales = build_all_scales_table(gts, all_gains, num_gains); - if (IS_ERR(all_scales)) - return PTR_ERR(all_scales); - - gts->num_avail_all_scales = num_gains; + gts->num_avail_all_scales = new_idx / 2; gts->avail_all_scales_table = all_scales; return 0; @@ -279,15 +254,15 @@ static int build_combined_tables(struct iio_gts *gts, static int gain_to_scaletables(struct iio_gts *gts, int **gains, int **scales) { int ret; - size_t gain_bytes; + size_t scale_bytes; ret = fill_and_sort_scaletables(gts, gains, scales); if (ret) return ret; - gain_bytes = array_size(gts->num_hwgain, sizeof(int)); + scale_bytes = array_size(gts->num_hwgain, 2 * sizeof(int)); - return build_combined_tables(gts, gains, gain_bytes); + return do_combined_scaletable(gts, scales, scale_bytes); } /**
The GTS helpers offer two different set of "available scales" -tables. Drivers can choose to advertice the scales which are available on a currently selected integration time (by just changing the hwgain). Another option is to list all scales which can be supported using any of the integration times. This is useful for drivers which allow scale setting to also change the integration time to meet the scale user prefers. The helper function which build these tables for the GTS did firstbuild the "time specific" scale arrays for all the times. This is done by calculating the scales based on the integration time specific "total gain" arrays (gain contributed by both the integration time and hw-gain). After this the helper code calculates an array for all available scales. This is done combining all the time specific total-gains into one sorted array, removing dublicate gains and finally converting the gains to scales as above. This can be somewhat simplified by changing the logic for calculating the 'all available scales' -array to directly use the time specific scale arrays instead of time specific total-gain arrays. Code can directly just add all the already computed time specific scales to one big 'all scales'-array, keep it sorted and remove duplicates. Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> --- This has been tested by IIO-gts kunit tests only. All testing is appreciated. Comparing the scales is not as pretty as comparing the gains was, as scales are in two ints where the gains were in one. This makes the code slightly more hairy. I however believe that the logic is now more obvious. This might be more important for one reading this later... --- drivers/iio/industrialio-gts-helper.c | 109 ++++++++++---------------- 1 file changed, 42 insertions(+), 67 deletions(-)