On Sat, Jul 25, 2020 at 7:24 AM Kent Gibson <warthog618@xxxxxxxxx> wrote: > > Add support for requesting lines using the GPIO_GET_LINE_IOCTL, and > returning their current values using GPIOLINE_GET_VALUES_IOCTL. ... > +struct line { > + struct gpio_device *gdev; > + const char *label; > + u32 num_descs; > + /* descs must be last so it can be dynamically sized */ I guess [] implies above comment and thus comment can be dropped. > + struct gpio_desc *descs[]; > +}; ... > +static bool padding_not_zeroed(__u32 *padding, int pad_size) > +{ > + int i, sum = 0; > + > + for (i = 0; i < pad_size; i++) > + sum |= padding[i]; > + > + return sum; > +} Reimplementation of memchr_inv() ? ... > +static u64 gpioline_config_flags(struct gpioline_config *lc, int line_idx) > +{ > + int i; > + > + for (i = lc->num_attrs - 1; i >= 0; i--) { Much better to read is unsigned int i = lc->num_attrs; while (i--) { ... } > + if ((lc->attrs[i].attr.id == GPIOLINE_ATTR_ID_FLAGS) && > + test_bit(line_idx, (unsigned long *)lc->attrs[i].mask)) This casting is not good. What about BE 32-bit architecture? > + return lc->attrs[i].attr.flags; > + } > + return lc->flags; > +} > + > +static int gpioline_config_output_value(struct gpioline_config *lc, > + int line_idx) > +{ Same comments as per above. > +} ... > +static long line_get_values(struct line *line, void __user *ip) > +{ > + struct gpioline_values lv; > + unsigned long *vals = (unsigned long *)lv.bits; Casting u64 to unsigned long is not good. > +} ... > +static void line_free(struct line *line) > +{ > + int i; > + > + for (i = 0; i < line->num_descs; i++) { > + if (line->descs[i]) Redundant? > + gpiod_free(line->descs[i]); > + } > + kfree(line->label); > + put_device(&line->gdev->dev); > + kfree(line); > +} ... > + /* Make sure this is terminated */ > + linereq.consumer[sizeof(linereq.consumer)-1] = '\0'; > + if (strlen(linereq.consumer)) { > + line->label = kstrdup(linereq.consumer, GFP_KERNEL); kstrndup() ? > + if (!line->label) { > + ret = -ENOMEM; > + goto out_free_line; > + } > + } ... > + struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); I prefer to see this split, but it's minor. > + if (IS_ERR(desc)) { > + ret = PTR_ERR(desc); > + goto out_free_line; > + } ... > + dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", > + offset); Perhaps tracepoint / event? -- With Best Regards, Andy Shevchenko