On Tue, 26 May 2020 21:17:18 +0200 Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote: > Extract the logic out of nand_choose_data_interface() to create a > public helper that can be reused by manufacturer drivers. Add the > possibility to provide a specific set of timings. > > Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> > --- > drivers/mtd/nand/raw/internals.h | 3 + > drivers/mtd/nand/raw/nand_base.c | 104 +++++++++++++++++++------------ > 2 files changed, 66 insertions(+), 41 deletions(-) > > diff --git a/drivers/mtd/nand/raw/internals.h b/drivers/mtd/nand/raw/internals.h > index c7357ae86eeb..5c49c4d1e231 100644 > --- a/drivers/mtd/nand/raw/internals.h > +++ b/drivers/mtd/nand/raw/internals.h > @@ -90,6 +90,9 @@ int onfi_fill_data_interface(struct nand_chip *chip, > int timing_mode); > unsigned int > onfi_find_closest_sdr_mode(const struct nand_sdr_timings *spec_timings); > +int nand_choose_best_sdr_timings(struct nand_chip *chip, > + struct nand_data_interface *iface, > + struct nand_sdr_timings *spec_timings); > int nand_get_features(struct nand_chip *chip, int addr, u8 *subfeature_param); > int nand_set_features(struct nand_chip *chip, int addr, u8 *subfeature_param); > int nand_read_page_raw_notsupp(struct nand_chip *chip, u8 *buf, > diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c > index 6a7edd2e1357..b2e833a8ab9d 100644 > --- a/drivers/mtd/nand/raw/nand_base.c > +++ b/drivers/mtd/nand/raw/nand_base.c > @@ -1003,61 +1003,83 @@ static int nand_setup_data_interface(struct nand_chip *chip, int chipnr) > return ret; > } > > +/** > + * nand_choose_best_sdr_timings - Pick up the best SDR timings that both the > + * NAND controller and the NAND chip support > + * @chip: the NAND chip > + * @iface: the data interface (can eventually be updated) > + * @spec_timings: specific timings, when not fitting the ONFI specification > + * > + * If specific timings are provided, use them. Otherwise, try to retrieve > + * supported timing modes from ONFI information. Finally, if the NAND chip does > + * not follow the ONFI specification, rely on the ->default_timing_mode > + * specified in the nand_ids table. > + */ > +int nand_choose_best_sdr_timings(struct nand_chip *chip, > + struct nand_data_interface *iface, > + struct nand_sdr_timings *spec_timings) > +{ > + const struct nand_controller_ops *ops = chip->controller->ops; > + int best_mode = 0, onfi_modes, mode, ret; > + > + iface->type = NAND_SDR_IFACE; > + > + if (spec_timings) { > + iface->timings.sdr = *spec_timings; > + iface->timings.mode = onfi_find_closest_sdr_mode(spec_timings); > + > + /* Verify the controller supports the requested interface */ > + ret = ops->setup_data_interface(chip, > + NAND_DATA_IFACE_CHECK_ONLY, > + iface); > + if (!ret) > + return ret; > + > + /* Fallback to slower modes */ > + best_mode = iface->timings.mode; > + } else { > + if (chip->parameters.onfi) { onfi_modes var should be declared here. > + onfi_modes = chip->parameters.onfi->async_timing_mode; > + best_mode = fls(onfi_modes) - 1; > + } else { > + best_mode = chip->onfi_timing_mode_default; > + } > + } > + > + > + for (mode = best_mode; mode >= 0; mode--) { > + ret = onfi_fill_data_interface(chip, iface, NAND_SDR_IFACE, > + mode); > + if (ret) > + continue; In practice onfi_fill_data_interface() will only return an error if you pass a type that's not SDR (not the case here, or a mode that's outside the SDR mode bounds). Maybe we should just clamp the value/warn when that happens and make onfi_fill_data_interface() a void function. > + > + ret = ops->setup_data_interface(chip, > + NAND_DATA_IFACE_CHECK_ONLY, > + iface); > + if (!ret) > + break; return 0; > + } > + > + return 0; > +} > + > /** > * nand_choose_data_interface - find the best data interface and timings > * @chip: The NAND chip > * > * Find the best data interface and NAND timings supported by the chip > * and the driver. > - * First tries to retrieve supported timing modes from ONFI information, > - * and if the NAND chip does not support ONFI, relies on the > - * ->onfi_timing_mode_default specified in the nand_ids table. After this > - * function nand_chip->data_interface is initialized with the best timing mode > - * available. > + * After this function nand_chip->data_interface is initialized with the best > + * timing mode available. > * > * Returns 0 for success or negative error code otherwise. > */ > static int nand_choose_data_interface(struct nand_chip *chip) > { > - int modes, mode, ret; > - > if (!nand_controller_has_setup_data_iface(chip)) > return 0; > > - /* > - * First try to identify the best timings from ONFI parameters and > - * if the NAND does not support ONFI, fallback to the default ONFI > - * timing mode. > - */ > - if (chip->parameters.onfi) { > - modes = chip->parameters.onfi->async_timing_mode; > - } else { > - if (!chip->onfi_timing_mode_default) > - return 0; > - > - modes = GENMASK(chip->onfi_timing_mode_default, 0); > - } > - > - for (mode = fls(modes) - 1; mode >= 0; mode--) { > - ret = onfi_fill_data_interface(chip, &chip->data_interface, > - NAND_SDR_IFACE, mode); > - if (ret) > - continue; > - > - /* > - * Pass NAND_DATA_IFACE_CHECK_ONLY to only check if the > - * controller supports the requested timings. > - */ > - ret = chip->controller->ops->setup_data_interface(chip, > - NAND_DATA_IFACE_CHECK_ONLY, > - &chip->data_interface); > - if (!ret) { > - chip->onfi_timing_mode_default = mode; > - break; > - } > - } > - > - return 0; > + return nand_choose_best_sdr_timings(chip, &chip->data_interface, NULL); > } > > /** ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/