On Fri, Jun 29, 2018 at 11:38 AM, Stefan Popa <stefan.popa@xxxxxxxxxx> wrote: > The AD5758 is a single channel DAC with 16-bit precision which uses the > SPI interface that operates at clock rates up to 50MHz. > > The output can be configured as voltage or current and is available on a > single terminal. > > Datasheet: > http://www.analog.com/media/en/technical-documentation/data-sheets/ad5758.pdf Thanks for an update. Few comments below. > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/spi/spi.h> > +#include <linux/property.h> > +#include <linux/delay.h> > +#include <linux/bsearch.h> Perhaps keep them ordered? > + > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +#include <asm/div64.h> ASM? Hmm... > +static int cmpfunc(const void *a, const void *b) > +{ > + return (*(int *)a - *(int *)b); Surrounding parens are not needed. > +} > + > +static int ad5758_find_closest_match(const int *array, > + unsigned int size, int val) > +{ > + int i; > + > + for (i = 0; i < size; i++) { > + if (val <= array[i]) > + return i; > + } > + > + return size - 1; > +} Isn't it what bsearch() covers as well? > + do { > + ret = ad5758_spi_reg_read(st, reg); > + if (ret < 0) > + return ret; > + > + if (!(ret & mask)) > + return 0; > + > + udelay(100); If it's not called from atomic context, perhaps switch to usleep_range() ? > + } while (--timeout); > +static int ad5758_soft_reset(struct ad5758_state *st) > +{ > + int ret; > + > + ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_1); > + if (ret < 0) > + return ret; > + > + ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_2); > + > + /* Perform a software reset and wait 100us */ > + udelay(100); Ditto. > + > + return ret; > +} > +static int ad5758_find_out_range(struct ad5758_state *st, > + const struct ad5758_range *range, > + unsigned int size, > + int min, int max) > +{ > + int i; > + > + for (i = 0; i < size; i++) { > + if ((min == range[i].min) && (max == range[i].max)) { > + st->out_range.reg = range[i].reg; > + st->out_range.min = range[i].min; > + st->out_range.max = range[i].max; > + > + return 0; > + } > + } One more candidate to use bsearch(). > + > + return -EINVAL; > +} > + index = (int *) bsearch(&tmp, ad5758_dc_dc_ilim, > + ARRAY_SIZE(ad5758_dc_dc_ilim), > + sizeof(int), cmpfunc); I'm not sure you need that casting. -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
