From 477b0229ac9bc275f6f8d2c27a2d08b246fccd0e Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Mon, 16 Nov 2015 15:53:13 +0100 Subject: mtd: introduce the mtd_pairing_scheme concept MLC and TLC NAND devices are using NAND cells exposing more than one bit, but instead of attaching all the bits in a given cell to a single NAND page, each bit is usually attached to a different page. This concept is called 'page pairing', and has significant impacts on the flash storage usage. The main problem showed by these devices is that interrupting a page program operation may not only corrupt the page we are programming but also the page it is paired with, hence the need to expose to MTD users the pairing scheme information. The pairing APIs allows one to query pairing information attached to a given page (here called wunit), or the other way around (the wunit pointed by pairing information). It also provides several helpers to help the conversion between absolute offsets and wunits, and query the number of pairing groups. Signed-off-by: Boris Brezillon Reviewed-by: Brian Norris --- include/linux/mtd/mtd.h | 107 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) (limited to 'include') diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 29a170612203..13f8052b9ff9 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -127,6 +127,82 @@ struct mtd_ooblayout_ops { struct mtd_oob_region *oobfree); }; +/** + * struct mtd_pairing_info - page pairing information + * + * @pair: pair id + * @group: group id + * + * The term "pair" is used here, even though TLC NANDs might group pages by 3 + * (3 bits in a single cell). A pair should regroup all pages that are sharing + * the same cell. Pairs are then indexed in ascending order. + * + * @group is defining the position of a page in a given pair. It can also be + * seen as the bit position in the cell: page attached to bit 0 belongs to + * group 0, page attached to bit 1 belongs to group 1, etc. + * + * Example: + * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme: + * + * group-0 group-1 + * + * pair-0 page-0 page-4 + * pair-1 page-1 page-5 + * pair-2 page-2 page-8 + * ... + * pair-127 page-251 page-255 + * + * + * Note that the "group" and "pair" terms were extracted from Samsung and + * Hynix datasheets, and might be referenced under other names in other + * datasheets (Micron is describing this concept as "shared pages"). + */ +struct mtd_pairing_info { + int pair; + int group; +}; + +/** + * struct mtd_pairing_scheme - page pairing scheme description + * + * @ngroups: number of groups. Should be related to the number of bits + * per cell. + * @get_info: converts a write-unit (page number within an erase block) into + * mtd_pairing information (pair + group). This function should + * fill the info parameter based on the wunit index or return + * -EINVAL if the wunit parameter is invalid. + * @get_wunit: converts pairing information into a write-unit (page) number. + * This function should return the wunit index pointed by the + * pairing information described in the info argument. It should + * return -EINVAL, if there's no wunit corresponding to the + * passed pairing information. + * + * See mtd_pairing_info documentation for a detailed explanation of the + * pair and group concepts. + * + * The mtd_pairing_scheme structure provides a generic solution to represent + * NAND page pairing scheme. Instead of exposing two big tables to do the + * write-unit <-> (pair + group) conversions, we ask the MTD drivers to + * implement the ->get_info() and ->get_wunit() functions. + * + * MTD users will then be able to query these information by using the + * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers. + * + * @ngroups is here to help MTD users iterating over all the pages in a + * given pair. This value can be retrieved by MTD users using the + * mtd_pairing_groups() helper. + * + * Examples are given in the mtd_pairing_info_to_wunit() and + * mtd_wunit_to_pairing_info() documentation. + */ +struct mtd_pairing_scheme { + int ngroups; + int (*get_info)(struct mtd_info *mtd, int wunit, + struct mtd_pairing_info *info); + int (*get_wunit)(struct mtd_info *mtd, + const struct mtd_pairing_info *info); +}; + struct module; /* only needed for owner field in mtd_info */ struct mtd_info { @@ -188,6 +264,9 @@ struct mtd_info { /* OOB layout description */ const struct mtd_ooblayout_ops *ooblayout; + /* NAND pairing scheme, only provided for MLC/TLC NANDs */ + const struct mtd_pairing_scheme *pairing; + /* the ecc step size. */ unsigned int ecc_step_size; @@ -296,6 +375,12 @@ static inline void mtd_set_ooblayout(struct mtd_info *mtd, mtd->ooblayout = ooblayout; } +static inline void mtd_set_pairing_scheme(struct mtd_info *mtd, + const struct mtd_pairing_scheme *pairing) +{ + mtd->pairing = pairing; +} + static inline void mtd_set_of_node(struct mtd_info *mtd, struct device_node *np) { @@ -312,6 +397,11 @@ static inline int mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops) return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize; } +int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit, + struct mtd_pairing_info *info); +int mtd_pairing_info_to_wunit(struct mtd_info *mtd, + const struct mtd_pairing_info *info); +int mtd_pairing_groups(struct mtd_info *mtd); int mtd_erase(struct mtd_info *mtd, struct erase_info *instr); int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, void **virt, resource_size_t *phys); @@ -397,6 +487,23 @@ static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd) return do_div(sz, mtd->writesize); } +static inline int mtd_wunit_per_eb(struct mtd_info *mtd) +{ + return mtd->erasesize / mtd->writesize; +} + +static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs) +{ + return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd); +} + +static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base, + int wunit) +{ + return base + (wunit * mtd->writesize); +} + + static inline int mtd_has_oob(const struct mtd_info *mtd) { return mtd->_read_oob && mtd->_write_oob; -- cgit v1.2.3 From d45bc58dd3bdcaabc1d7d8d9b0b8dee826635cc6 Mon Sep 17 00:00:00 2001 From: Marc Gonzalez Date: Wed, 27 Jul 2016 11:23:52 +0200 Subject: mtd: nand: import nand_hw_control_init() The code to initialize a struct nand_hw_control is duplicated across several drivers. Factorize it using an inline function. Signed-off-by: Marc Gonzalez Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 8dd6e01f45c0..f6a2d5e7313c 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -460,6 +460,13 @@ struct nand_hw_control { wait_queue_head_t wq; }; +static inline void nand_hw_control_init(struct nand_hw_control *nfc) +{ + nfc->active = NULL; + spin_lock_init(&nfc->lock); + init_waitqueue_head(&nfc->wq); +} + /** * struct nand_ecc_ctrl - Control structure for ECC * @mode: ECC mode -- cgit v1.2.3 From 79022591839f110f465cac0223e117b91d47d5db Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Wed, 7 Sep 2016 14:21:42 +0200 Subject: mtd: nand: remove unnecessary 'extern' from function declarations 'extern' is not necessary for function declarations. To prevent people from adding the keyword to new declarations remove the existing ones. Signed-off-by: Sascha Hauer Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index f6a2d5e7313c..28c1833ad708 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -29,26 +29,26 @@ struct nand_flash_dev; struct device_node; /* Scan and identify a NAND device */ -extern int nand_scan(struct mtd_info *mtd, int max_chips); +int nand_scan(struct mtd_info *mtd, int max_chips); /* * Separate phases of nand_scan(), allowing board driver to intervene * and override command or ECC setup according to flash type. */ -extern int nand_scan_ident(struct mtd_info *mtd, int max_chips, +int nand_scan_ident(struct mtd_info *mtd, int max_chips, struct nand_flash_dev *table); -extern int nand_scan_tail(struct mtd_info *mtd); +int nand_scan_tail(struct mtd_info *mtd); /* Free resources held by the NAND device */ -extern void nand_release(struct mtd_info *mtd); +void nand_release(struct mtd_info *mtd); /* Internal helper for board drivers which need to override command function */ -extern void nand_wait_ready(struct mtd_info *mtd); +void nand_wait_ready(struct mtd_info *mtd); /* locks all blocks present in the device */ -extern int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len); +int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len); /* unlocks specified locked blocks */ -extern int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len); +int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len); /* The maximum number of NAND chips in an array */ #define NAND_MAX_CHIPS 8 @@ -900,14 +900,14 @@ struct nand_manufacturers { extern struct nand_flash_dev nand_flash_ids[]; extern struct nand_manufacturers nand_manuf_ids[]; -extern int nand_default_bbt(struct mtd_info *mtd); -extern int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs); -extern int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs); -extern int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt); -extern int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr, - int allowbbt); -extern int nand_do_read(struct mtd_info *mtd, loff_t from, size_t len, - size_t *retlen, uint8_t *buf); +int nand_default_bbt(struct mtd_info *mtd); +int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs); +int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs); +int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt); +int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr, + int allowbbt); +int nand_do_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, uint8_t *buf); /** * struct platform_nand_chip - chip level device structure -- cgit v1.2.3 From 2f94abfe35b210e7711af9202a3dcfc9e779219a Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Thu, 15 Sep 2016 10:32:45 +0200 Subject: mtd: nand: Create a NAND reset function When NAND devices are resetted some initialization may have to be done, like for example they have to be configured for the timing mode that shall be used. To get a common place where this initialization can be implemented create a nand_reset() function. This currently only issues a NAND_CMD_RESET to the NAND device. The places issuing this command manually are replaced with a call to nand_reset(). Signed-off-by: Sascha Hauer Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 28c1833ad708..73ccbf6e057c 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -1100,4 +1100,8 @@ int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page); /* Default read_oob syndrome implementation */ int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip, int page); + +/* Reset and initialize a NAND device */ +int nand_reset(struct nand_chip *chip); + #endif /* __LINUX_MTD_NAND_H */ -- cgit v1.2.3 From eee64b700e26b9bcc6fce024681c31f5e12271fc Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Thu, 15 Sep 2016 10:32:46 +0200 Subject: mtd: nand: Introduce nand_data_interface Currently we have no data structure to fully describe a NAND timing. We only have struct nand_sdr_timings for NAND timings in SDR mode, but nothing for DDR mode and also no container to store both types of timing. This patch adds struct nand_data_interface which stores the timing type and a union of different timings. This can be used to pass to drivers in order to configure the timing. Add kerneldoc for struct nand_sdr_timings while touching it anyway. Signed-off-by: Sascha Hauer Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 166 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 117 insertions(+), 49 deletions(-) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 73ccbf6e057c..a625e960c0c3 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -572,6 +572,123 @@ struct nand_buffers { uint8_t *databuf; }; +/** + * struct nand_sdr_timings - SDR NAND chip timings + * + * This struct defines the timing requirements of a SDR NAND chip. + * These information can be found in every NAND datasheets and the timings + * meaning are described in the ONFI specifications: + * www.onfi.org/~/media/ONFI/specs/onfi_3_1_spec.pdf (chapter 4.15 Timing + * Parameters) + * + * All these timings are expressed in picoseconds. + * + * @tALH_min: ALE hold time + * @tADL_min: ALE to data loading time + * @tALS_min: ALE setup time + * @tAR_min: ALE to RE# delay + * @tCEA_max: CE# access time + * @tCEH_min: + * @tCH_min: CE# hold time + * @tCHZ_max: CE# high to output hi-Z + * @tCLH_min: CLE hold time + * @tCLR_min: CLE to RE# delay + * @tCLS_min: CLE setup time + * @tCOH_min: CE# high to output hold + * @tCS_min: CE# setup time + * @tDH_min: Data hold time + * @tDS_min: Data setup time + * @tFEAT_max: Busy time for Set Features and Get Features + * @tIR_min: Output hi-Z to RE# low + * @tITC_max: Interface and Timing Mode Change time + * @tRC_min: RE# cycle time + * @tREA_max: RE# access time + * @tREH_min: RE# high hold time + * @tRHOH_min: RE# high to output hold + * @tRHW_min: RE# high to WE# low + * @tRHZ_max: RE# high to output hi-Z + * @tRLOH_min: RE# low to output hold + * @tRP_min: RE# pulse width + * @tRR_min: Ready to RE# low (data only) + * @tRST_max: Device reset time, measured from the falling edge of R/B# to the + * rising edge of R/B#. + * @tWB_max: WE# high to SR[6] low + * @tWC_min: WE# cycle time + * @tWH_min: WE# high hold time + * @tWHR_min: WE# high to RE# low + * @tWP_min: WE# pulse width + * @tWW_min: WP# transition to WE# low + */ +struct nand_sdr_timings { + u32 tALH_min; + u32 tADL_min; + u32 tALS_min; + u32 tAR_min; + u32 tCEA_max; + u32 tCEH_min; + u32 tCH_min; + u32 tCHZ_max; + u32 tCLH_min; + u32 tCLR_min; + u32 tCLS_min; + u32 tCOH_min; + u32 tCS_min; + u32 tDH_min; + u32 tDS_min; + u32 tFEAT_max; + u32 tIR_min; + u32 tITC_max; + u32 tRC_min; + u32 tREA_max; + u32 tREH_min; + u32 tRHOH_min; + u32 tRHW_min; + u32 tRHZ_max; + u32 tRLOH_min; + u32 tRP_min; + u32 tRR_min; + u64 tRST_max; + u32 tWB_max; + u32 tWC_min; + u32 tWH_min; + u32 tWHR_min; + u32 tWP_min; + u32 tWW_min; +}; + +/** + * enum nand_data_interface_type - NAND interface timing type + * @NAND_SDR_IFACE: Single Data Rate interface + */ +enum nand_data_interface_type { + NAND_SDR_IFACE, +}; + +/** + * struct nand_data_interface - NAND interface timing + * @type: type of the timing + * @timings: The timing, type according to @type + */ +struct nand_data_interface { + enum nand_data_interface_type type; + union { + struct nand_sdr_timings sdr; + } timings; +}; + +/** + * nand_get_sdr_timings - get SDR timing from data interface + * @conf: The data interface + */ +static inline const struct nand_sdr_timings * +nand_get_sdr_timings(const struct nand_data_interface *conf) +{ + if (conf->type != NAND_SDR_IFACE) + return ERR_PTR(-EINVAL); + + return &conf->timings.sdr; +} + /** * struct nand_chip - NAND Private Flash Chip Data * @mtd: MTD device registered to the MTD framework @@ -1030,55 +1147,6 @@ static inline int jedec_feature(struct nand_chip *chip) : 0; } -/* - * struct nand_sdr_timings - SDR NAND chip timings - * - * This struct defines the timing requirements of a SDR NAND chip. - * These informations can be found in every NAND datasheets and the timings - * meaning are described in the ONFI specifications: - * www.onfi.org/~/media/ONFI/specs/onfi_3_1_spec.pdf (chapter 4.15 Timing - * Parameters) - * - * All these timings are expressed in picoseconds. - */ - -struct nand_sdr_timings { - u32 tALH_min; - u32 tADL_min; - u32 tALS_min; - u32 tAR_min; - u32 tCEA_max; - u32 tCEH_min; - u32 tCH_min; - u32 tCHZ_max; - u32 tCLH_min; - u32 tCLR_min; - u32 tCLS_min; - u32 tCOH_min; - u32 tCS_min; - u32 tDH_min; - u32 tDS_min; - u32 tFEAT_max; - u32 tIR_min; - u32 tITC_max; - u32 tRC_min; - u32 tREA_max; - u32 tREH_min; - u32 tRHOH_min; - u32 tRHW_min; - u32 tRHZ_max; - u32 tRLOH_min; - u32 tRP_min; - u32 tRR_min; - u64 tRST_max; - u32 tWB_max; - u32 tWC_min; - u32 tWH_min; - u32 tWHR_min; - u32 tWP_min; - u32 tWW_min; -}; - /* get timing characteristics from ONFI timing mode. */ const struct nand_sdr_timings *onfi_async_timing_mode_to_sdr_timings(int mode); -- cgit v1.2.3 From b88730ada99bfe243862add360720a3550b0edbf Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Thu, 15 Sep 2016 10:32:48 +0200 Subject: mtd: nand: Add function to convert ONFI mode to data_interface onfi_init_data_interface() initializes a data interface with values from a given ONFI mode. Signed-off-by: Sascha Hauer Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index a625e960c0c3..1f34c04fe16c 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -1112,6 +1112,11 @@ static inline int onfi_get_sync_timing_mode(struct nand_chip *chip) return le16_to_cpu(chip->onfi_params.src_sync_timing_mode); } +int onfi_init_data_interface(struct nand_chip *chip, + struct nand_data_interface *iface, + enum nand_data_interface_type type, + int timing_mode); + /* * Check if it is a SLC nand. * The !nand_is_slc() can be used to check the MLC/TLC nand chips. -- cgit v1.2.3 From 6e1f9708dbf3c50a8da93c1952a01a7a2acb5e66 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Thu, 15 Sep 2016 10:32:49 +0200 Subject: mtd: nand: Expose data interface for ONFI mode 0 The nand layer will need ONFI mode 0 to use it as timing mode before and right after reset. Signed-off-by: Sascha Hauer Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 1f34c04fe16c..0c9412c2d80b 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -1154,6 +1154,8 @@ static inline int jedec_feature(struct nand_chip *chip) /* get timing characteristics from ONFI timing mode. */ const struct nand_sdr_timings *onfi_async_timing_mode_to_sdr_timings(int mode); +/* get data interface from ONFI timing mode 0, used after reset. */ +const struct nand_data_interface *nand_get_default_data_interface(void); int nand_check_erased_ecc_chunk(void *data, int datalen, void *ecc, int ecclen, -- cgit v1.2.3 From d8e725dd831186a3595036b2b1df9f68cbc6efa3 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Thu, 15 Sep 2016 10:32:50 +0200 Subject: mtd: nand: automate NAND timings selection The NAND framework provides several helpers to query timing modes supported by a NAND chip, but this implies that all NAND controller drivers have to implement the same timings selection dance. Also currently NAND devices can be resetted at arbitrary places which also resets the timing for ONFI chips to timing mode 0. Provide a common logic to select the best timings based on ONFI or ->onfi_timing_mode_default information. Hook this into nand_reset() to make sure the new timing is applied each time during a reset. NAND controller willing to support timings adjustment should just implement the ->setup_data_interface() method. Signed-off-by: Boris Brezillon Signed-off-by: Sascha Hauer --- include/linux/mtd/nand.h | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 0c9412c2d80b..d3e3f8d03336 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -751,10 +751,9 @@ nand_get_sdr_timings(const struct nand_data_interface *conf) * also from the datasheet. It is the recommended ECC step * size, if known; if unknown, set to zero. * @onfi_timing_mode_default: [INTERN] default ONFI timing mode. This field is - * either deduced from the datasheet if the NAND - * chip is not ONFI compliant or set to 0 if it is - * (an ONFI chip is always configured in mode 0 - * after a NAND reset) + * set to the actually used ONFI mode if the chip is + * ONFI compliant or deduced from the datasheet if + * the NAND chip is not ONFI compliant. * @numchips: [INTERN] number of physical chips * @chipsize: [INTERN] the size of one chip for multichip arrays * @pagemask: [INTERN] page number mask = number of (pages / chip) - 1 @@ -774,6 +773,7 @@ nand_get_sdr_timings(const struct nand_data_interface *conf) * @read_retries: [INTERN] the number of read retry modes supported * @onfi_set_features: [REPLACEABLE] set the features for ONFI nand * @onfi_get_features: [REPLACEABLE] get the features for ONFI nand + * @setup_data_interface: [OPTIONAL] setup the data interface and timing * @bbt: [INTERN] bad block table pointer * @bbt_td: [REPLACEABLE] bad block table descriptor for flash * lookup. @@ -820,6 +820,10 @@ struct nand_chip { int (*onfi_get_features)(struct mtd_info *mtd, struct nand_chip *chip, int feature_addr, uint8_t *subfeature_para); int (*setup_read_retry)(struct mtd_info *mtd, int retry_mode); + int (*setup_data_interface)(struct mtd_info *mtd, + const struct nand_data_interface *conf, + bool check_only); + int chip_delay; unsigned int options; @@ -849,6 +853,8 @@ struct nand_chip { struct nand_jedec_params jedec_params; }; + struct nand_data_interface *data_interface; + int read_retries; flstate_t state; -- cgit v1.2.3 From ba78ee00e1ff84de9b3ad33edbd3ec599099ee82 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Wed, 8 Jun 2016 17:04:22 +0200 Subject: mtd: nand: Add an option to maximize the ECC strength The generic NAND DT bindings allows one to tweak the ECC strength and step size to their need. It can be used to lower the ECC strength to match a bootloader/firmware config, but might also be used to get a better reliability. In the latter case, the user might want to use the maximum ECC strength without having to explicitly calculate the exact value (this value not only depends on the OOB size, but also on the NAND controller, and can be tricky to extract). Add a generic 'nand-ecc-maximize' DT property and the associated NAND_ECC_MAXIMIZE flag, to let ECC controller drivers select the best ECC strength and step-size on their own. Signed-off-by: Boris Brezillon Acked-by: Rob Herring --- include/linux/mtd/nand.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index d3e3f8d03336..331caf987b16 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -141,6 +141,7 @@ enum nand_ecc_algo { * pages and you want to rely on the default implementation. */ #define NAND_ECC_GENERIC_ERASED_CHECK BIT(0) +#define NAND_ECC_MAXIMIZE BIT(1) /* Bit mask for flags passed to do_nand_read_ecc */ #define NAND_GET_DEVICE 0x80 -- cgit v1.2.3 From d44154f969a44269a9288c274c1c2fd9e85df8a5 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Wed, 21 Sep 2016 11:44:41 +0200 Subject: mtd: nand: Provide nand_cleanup() function to free NAND related resources Provide a nand_cleanup() function to free all nand related resources without unregistering the mtd device. This should allow drivers to call mtd_device_unregister() and handle its return value and still being able to cleanup all nand related resources. Signed-off-by: Richard Weinberger Signed-off-by: Daniel Walter Signed-off-by: Boris Brezillon --- include/linux/mtd/nand.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 331caf987b16..c5d3d5024fc8 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -38,7 +38,7 @@ int nand_scan_ident(struct mtd_info *mtd, int max_chips, struct nand_flash_dev *table); int nand_scan_tail(struct mtd_info *mtd); -/* Free resources held by the NAND device */ +/* Unregister the MTD device and free resources held by the NAND device */ void nand_release(struct mtd_info *mtd); /* Internal helper for board drivers which need to override command function */ @@ -1186,4 +1186,7 @@ int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip, /* Reset and initialize a NAND device */ int nand_reset(struct nand_chip *chip); +/* Free resources held by the NAND device */ +void nand_cleanup(struct nand_chip *chip); + #endif /* __LINUX_MTD_NAND_H */ -- cgit v1.2.3