// SPDX-License-Identifier: GPL-2.0-or-later /* * Handles the M-Systems DiskOnChip G3 chip * * Copyright (C) 2011 Robert Jarzmik */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/io.h> #include <linux/delay.h> #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> #include <linux/bitmap.h> #include <linux/bitrev.h> #include <linux/bch.h> #include <linux/debugfs.h> #include <linux/seq_file.h> #define CREATE_TRACE_POINTS #include "docg3.h" /* * This driver handles the DiskOnChip G3 flash memory. * * As no specification is available from M-Systems/Sandisk, this drivers lacks * several functions available on the chip, as : * - IPL write * * The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and * the driver assumes a 16bits data bus. * * DocG3 relies on 2 ECC algorithms, which are handled in hardware : * - a 1 byte Hamming code stored in the OOB for each page * - a 7 bytes BCH code stored in the OOB for each page * The BCH ECC is : * - BCH is in GF(2^14) * - BCH is over data of 520 bytes (512 page + 7 page_info bytes * + 1 hamming byte) * - BCH can correct up to 4 bits (t = 4) * - BCH syndroms are calculated in hardware, and checked in hardware as well * */ static unsigned int reliable_mode; module_param(reliable_mode, uint, 0); MODULE_PARM_DESC(…) …; static int docg3_ooblayout_ecc(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { … } static int docg3_ooblayout_free(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { … } static const struct mtd_ooblayout_ops nand_ooblayout_docg3_ops = …; static inline u8 doc_readb(struct docg3 *docg3, u16 reg) { … } static inline u16 doc_readw(struct docg3 *docg3, u16 reg) { … } static inline void doc_writeb(struct docg3 *docg3, u8 val, u16 reg) { … } static inline void doc_writew(struct docg3 *docg3, u16 val, u16 reg) { … } static inline void doc_flash_command(struct docg3 *docg3, u8 cmd) { … } static inline void doc_flash_sequence(struct docg3 *docg3, u8 seq) { … } static inline void doc_flash_address(struct docg3 *docg3, u8 addr) { … } static char const * const part_probes[] = …; static int doc_register_readb(struct docg3 *docg3, int reg) { … } static int doc_register_readw(struct docg3 *docg3, int reg) { … } /** * doc_delay - delay docg3 operations * @docg3: the device * @nbNOPs: the number of NOPs to issue * * As no specification is available, the right timings between chip commands are * unknown. The only available piece of information are the observed nops on a * working docg3 chip. * Therefore, doc_delay relies on a busy loop of NOPs, instead of scheduler * friendlier msleep() functions or blocking mdelay(). */ static void doc_delay(struct docg3 *docg3, int nbNOPs) { … } static int is_prot_seq_error(struct docg3 *docg3) { … } static int doc_is_ready(struct docg3 *docg3) { … } static int doc_wait_ready(struct docg3 *docg3) { … } static int doc_reset_seq(struct docg3 *docg3) { … } /** * doc_read_data_area - Read data from data area * @docg3: the device * @buf: the buffer to fill in (might be NULL is dummy reads) * @len: the length to read * @first: first time read, DOC_READADDRESS should be set * * Reads bytes from flash data. Handles the single byte / even bytes reads. */ static void doc_read_data_area(struct docg3 *docg3, void *buf, int len, int first) { … } /** * doc_write_data_area - Write data into data area * @docg3: the device * @buf: the buffer to get input bytes from * @len: the length to write * * Writes bytes into flash data. Handles the single byte / even bytes writes. */ static void doc_write_data_area(struct docg3 *docg3, const void *buf, int len) { … } /** * doc_set_reliable_mode - Sets the flash to normal or reliable data mode * @docg3: the device * * The reliable data mode is a bit slower than the fast mode, but less errors * occur. Entering the reliable mode cannot be done without entering the fast * mode first. * * In reliable mode, pages 2*n and 2*n+1 are clones. Writing to page 0 of blocks * (4,5) make the hardware write also to page 1 of blocks blocks(4,5). Reading * from page 0 of blocks (4,5) or from page 1 of blocks (4,5) gives the same * result, which is a logical and between bytes from page 0 and page 1 (which is * consistent with the fact that writing to a page is _clearing_ bits of that * page). */ static void doc_set_reliable_mode(struct docg3 *docg3) { … } /** * doc_set_asic_mode - Set the ASIC mode * @docg3: the device * @mode: the mode * * The ASIC can work in 3 modes : * - RESET: all registers are zeroed * - NORMAL: receives and handles commands * - POWERDOWN: minimal poweruse, flash parts shut off */ static void doc_set_asic_mode(struct docg3 *docg3, u8 mode) { … } /** * doc_set_device_id - Sets the devices id for cascaded G3 chips * @docg3: the device * @id: the chip to select (amongst 0, 1, 2, 3) * * There can be 4 cascaded G3 chips. This function selects the one which will * should be the active one. */ static void doc_set_device_id(struct docg3 *docg3, int id) { … } /** * doc_set_extra_page_mode - Change flash page layout * @docg3: the device * * Normally, the flash page is split into the data (512 bytes) and the out of * band data (16 bytes). For each, 4 more bytes can be accessed, where the wear * leveling counters are stored. To access this last area of 4 bytes, a special * mode must be input to the flash ASIC. * * Returns 0 if no error occurred, -EIO else. */ static int doc_set_extra_page_mode(struct docg3 *docg3) { … } /** * doc_setup_addr_sector - Setup blocks/page/ofs address for one plane * @docg3: the device * @sector: the sector */ static void doc_setup_addr_sector(struct docg3 *docg3, int sector) { … } /** * doc_setup_writeaddr_sector - Setup blocks/page/ofs address for one plane * @docg3: the device * @sector: the sector * @ofs: the offset in the page, between 0 and (512 + 16 + 512) */ static void doc_setup_writeaddr_sector(struct docg3 *docg3, int sector, int ofs) { … } /** * doc_read_seek - Set both flash planes to the specified block, page for reading * @docg3: the device * @block0: the first plane block index * @block1: the second plane block index * @page: the page index within the block * @wear: if true, read will occur on the 4 extra bytes of the wear area * @ofs: offset in page to read * * Programs the flash even and odd planes to the specific block and page. * Alternatively, programs the flash to the wear area of the specified page. */ static int doc_read_seek(struct docg3 *docg3, int block0, int block1, int page, int wear, int ofs) { … } /** * doc_write_seek - Set both flash planes to the specified block, page for writing * @docg3: the device * @block0: the first plane block index * @block1: the second plane block index * @page: the page index within the block * @ofs: offset in page to write * * Programs the flash even and odd planes to the specific block and page. * Alternatively, programs the flash to the wear area of the specified page. */ static int doc_write_seek(struct docg3 *docg3, int block0, int block1, int page, int ofs) { … } /** * doc_read_page_ecc_init - Initialize hardware ECC engine * @docg3: the device * @len: the number of bytes covered by the ECC (BCH covered) * * The function does initialize the hardware ECC engine to compute the Hamming * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes). * * Return 0 if succeeded, -EIO on error */ static int doc_read_page_ecc_init(struct docg3 *docg3, int len) { … } /** * doc_write_page_ecc_init - Initialize hardware BCH ECC engine * @docg3: the device * @len: the number of bytes covered by the ECC (BCH covered) * * The function does initialize the hardware ECC engine to compute the Hamming * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes). * * Return 0 if succeeded, -EIO on error */ static int doc_write_page_ecc_init(struct docg3 *docg3, int len) { … } /** * doc_ecc_disable - Disable Hamming and BCH ECC hardware calculator * @docg3: the device * * Disables the hardware ECC generator and checker, for unchecked reads (as when * reading OOB only or write status byte). */ static void doc_ecc_disable(struct docg3 *docg3) { … } /** * doc_hamming_ecc_init - Initialize hardware Hamming ECC engine * @docg3: the device * @nb_bytes: the number of bytes covered by the ECC (Hamming covered) * * This function programs the ECC hardware to compute the hamming code on the * last provided N bytes to the hardware generator. */ static void doc_hamming_ecc_init(struct docg3 *docg3, int nb_bytes) { … } /** * doc_ecc_bch_fix_data - Fix if need be read data from flash * @docg3: the device * @buf: the buffer of read data (512 + 7 + 1 bytes) * @hwecc: the hardware calculated ECC. * It's in fact recv_ecc ^ calc_ecc, where recv_ecc was read from OOB * area data, and calc_ecc the ECC calculated by the hardware generator. * * Checks if the received data matches the ECC, and if an error is detected, * tries to fix the bit flips (at most 4) in the buffer buf. As the docg3 * understands the (data, ecc, syndroms) in an inverted order in comparison to * the BCH library, the function reverses the order of bits (ie. bit7 and bit0, * bit6 and bit 1, ...) for all ECC data. * * The hardware ecc unit produces oob_ecc ^ calc_ecc. The kernel's bch * algorithm is used to decode this. However the hw operates on page * data in a bit order that is the reverse of that of the bch alg, * requiring that the bits be reversed on the result. Thanks to Ivan * Djelic for his analysis. * * Returns number of fixed bits (0, 1, 2, 3, 4) or -EBADMSG if too many bit * errors were detected and cannot be fixed. */ static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc) { … } /** * doc_read_page_prepare - Prepares reading data from a flash page * @docg3: the device * @block0: the first plane block index on flash memory * @block1: the second plane block index on flash memory * @page: the page index in the block * @offset: the offset in the page (must be a multiple of 4) * * Prepares the page to be read in the flash memory : * - tell ASIC to map the flash pages * - tell ASIC to be in read mode * * After a call to this method, a call to doc_read_page_finish is mandatory, * to end the read cycle of the flash. * * Read data from a flash page. The length to be read must be between 0 and * (page_size + oob_size + wear_size), ie. 532, and a multiple of 4 (because * the extra bytes reading is not implemented). * * As pages are grouped by 2 (in 2 planes), reading from a page must be done * in two steps: * - one read of 512 bytes at offset 0 * - one read of 512 bytes at offset 512 + 16 * * Returns 0 if successful, -EIO if a read error occurred. */ static int doc_read_page_prepare(struct docg3 *docg3, int block0, int block1, int page, int offset) { … } /** * doc_read_page_getbytes - Reads bytes from a prepared page * @docg3: the device * @len: the number of bytes to be read (must be a multiple of 4) * @buf: the buffer to be filled in (or NULL is forget bytes) * @first: 1 if first time read, DOC_READADDRESS should be set * @last_odd: 1 if last read ended up on an odd byte * * Reads bytes from a prepared page. There is a trickery here : if the last read * ended up on an odd offset in the 1024 bytes double page, ie. between the 2 * planes, the first byte must be read apart. If a word (16bit) read was used, * the read would return the byte of plane 2 as low *and* high endian, which * will mess the read. * */ static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf, int first, int last_odd) { … } /** * doc_write_page_putbytes - Writes bytes into a prepared page * @docg3: the device * @len: the number of bytes to be written * @buf: the buffer of input bytes * */ static void doc_write_page_putbytes(struct docg3 *docg3, int len, const u_char *buf) { … } /** * doc_get_bch_hw_ecc - Get hardware calculated BCH ECC * @docg3: the device * @hwecc: the array of 7 integers where the hardware ecc will be stored */ static void doc_get_bch_hw_ecc(struct docg3 *docg3, u8 *hwecc) { … } /** * doc_page_finish - Ends reading/writing of a flash page * @docg3: the device */ static void doc_page_finish(struct docg3 *docg3) { … } /** * doc_read_page_finish - Ends reading of a flash page * @docg3: the device * * As a side effect, resets the chip selector to 0. This ensures that after each * read operation, the floor 0 is selected. Therefore, if the systems halts, the * reboot will boot on floor 0, where the IPL is. */ static void doc_read_page_finish(struct docg3 *docg3) { … } /** * calc_block_sector - Calculate blocks, pages and ofs. * * @from: offset in flash * @block0: first plane block index calculated * @block1: second plane block index calculated * @page: page calculated * @ofs: offset in page * @reliable: 0 if docg3 in normal mode, 1 if docg3 in fast mode, 2 if docg3 in * reliable mode. * * The calculation is based on the reliable/normal mode. In normal mode, the 64 * pages of a block are available. In reliable mode, as pages 2*n and 2*n+1 are * clones, only 32 pages per block are available. */ static void calc_block_sector(loff_t from, int *block0, int *block1, int *page, int *ofs, int reliable) { … } /** * doc_read_oob - Read out of band bytes from flash * @mtd: the device * @from: the offset from first block and first page, in bytes, aligned on page * size * @ops: the mtd oob structure * * Reads flash memory OOB area of pages. * * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred */ static int doc_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) { … } static int doc_reload_bbt(struct docg3 *docg3) { … } /** * doc_block_isbad - Checks whether a block is good or not * @mtd: the device * @from: the offset to find the correct block * * Returns 1 if block is bad, 0 if block is good */ static int doc_block_isbad(struct mtd_info *mtd, loff_t from) { … } #if 0 /** * doc_get_erase_count - Get block erase count * @docg3: the device * @from: the offset in which the block is. * * Get the number of times a block was erased. The number is the maximum of * erase times between first and second plane (which should be equal normally). * * Returns The number of erases, or -EINVAL or -EIO on error. */ static int doc_get_erase_count(struct docg3 *docg3, loff_t from) { u8 buf[DOC_LAYOUT_WEAR_SIZE]; int ret, plane1_erase_count, plane2_erase_count; int block0, block1, page, ofs; doc_dbg("doc_get_erase_count(from=%lld, buf=%p)\n", from, buf); if (from % DOC_LAYOUT_PAGE_SIZE) return -EINVAL; calc_block_sector(from, &block0, &block1, &page, &ofs, docg3->reliable); if (block1 > docg3->max_block) return -EINVAL; ret = doc_reset_seq(docg3); if (!ret) ret = doc_read_page_prepare(docg3, block0, block1, page, ofs + DOC_LAYOUT_WEAR_OFFSET, 0); if (!ret) ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_WEAR_SIZE, buf, 1, 0); doc_read_page_finish(docg3); if (ret || (buf[0] != DOC_ERASE_MARK) || (buf[2] != DOC_ERASE_MARK)) return -EIO; plane1_erase_count = (u8)(~buf[1]) | ((u8)(~buf[4]) << 8) | ((u8)(~buf[5]) << 16); plane2_erase_count = (u8)(~buf[3]) | ((u8)(~buf[6]) << 8) | ((u8)(~buf[7]) << 16); return max(plane1_erase_count, plane2_erase_count); } #endif /** * doc_get_op_status - get erase/write operation status * @docg3: the device * * Queries the status from the chip, and returns it * * Returns the status (bits DOC_PLANES_STATUS_*) */ static int doc_get_op_status(struct docg3 *docg3) { … } /** * doc_write_erase_wait_status - wait for write or erase completion * @docg3: the device * * Wait for the chip to be ready again after erase or write operation, and check * erase/write status. * * Returns 0 if erase successful, -EIO if erase/write issue, -ETIMEOUT if * timeout */ static int doc_write_erase_wait_status(struct docg3 *docg3) { … } /** * doc_erase_block - Erase a couple of blocks * @docg3: the device * @block0: the first block to erase (leftmost plane) * @block1: the second block to erase (rightmost plane) * * Erase both blocks, and return operation status * * Returns 0 if erase successful, -EIO if erase issue, -ETIMEOUT if chip not * ready for too long */ static int doc_erase_block(struct docg3 *docg3, int block0, int block1) { … } /** * doc_erase - Erase a portion of the chip * @mtd: the device * @info: the erase info * * Erase a bunch of contiguous blocks, by pairs, as a "mtd" page of 1024 is * split into 2 pages of 512 bytes on 2 contiguous blocks. * * Returns 0 if erase successful, -EINVAL if addressing error, -EIO if erase * issue */ static int doc_erase(struct mtd_info *mtd, struct erase_info *info) { … } /** * doc_write_page - Write a single page to the chip * @docg3: the device * @to: the offset from first block and first page, in bytes, aligned on page * size * @buf: buffer to get bytes from * @oob: buffer to get out of band bytes from (can be NULL if no OOB should be * written) * @autoecc: if 0, all 16 bytes from OOB are taken, regardless of HW Hamming or * BCH computations. If 1, only bytes 0-7 and byte 15 are taken, * remaining ones are filled with hardware Hamming and BCH * computations. Its value is not meaningfull is oob == NULL. * * Write one full page (ie. 1 page split on two planes), of 512 bytes, with the * OOB data. The OOB ECC is automatically computed by the hardware Hamming and * BCH generator if autoecc is not null. * * Returns 0 if write successful, -EIO if write error, -EAGAIN if timeout */ static int doc_write_page(struct docg3 *docg3, loff_t to, const u_char *buf, const u_char *oob, int autoecc) { … } /** * doc_guess_autoecc - Guess autoecc mode from mbd_oob_ops * @ops: the oob operations * * Returns 0 or 1 if success, -EINVAL if invalid oob mode */ static int doc_guess_autoecc(struct mtd_oob_ops *ops) { … } /** * doc_fill_autooob - Fill a 16 bytes OOB from 8 non-ECC bytes * @dst: the target 16 bytes OOB buffer * @oobsrc: the source 8 bytes non-ECC OOB buffer * */ static void doc_fill_autooob(u8 *dst, u8 *oobsrc) { … } /** * doc_backup_oob - Backup OOB into docg3 structure * @docg3: the device * @to: the page offset in the chip * @ops: the OOB size and buffer * * As the docg3 should write a page with its OOB in one pass, and some userland * applications do write_oob() to setup the OOB and then write(), store the OOB * into a temporary storage. This is very dangerous, as 2 concurrent * applications could store an OOB, and then write their pages (which will * result into one having its OOB corrupted). * * The only reliable way would be for userland to call doc_write_oob() with both * the page data _and_ the OOB area. * * Returns 0 if success, -EINVAL if ops content invalid */ static int doc_backup_oob(struct docg3 *docg3, loff_t to, struct mtd_oob_ops *ops) { … } /** * doc_write_oob - Write out of band bytes to flash * @mtd: the device * @ofs: the offset from first block and first page, in bytes, aligned on page * size * @ops: the mtd oob structure * * Either write OOB data into a temporary buffer, for the subsequent write * page. The provided OOB should be 16 bytes long. If a data buffer is provided * as well, issue the page write. * Or provide data without OOB, and then a all zeroed OOB will be used (ECC will * still be filled in if asked for). * * Returns 0 is successful, EINVAL if length is not 14 bytes */ static int doc_write_oob(struct mtd_info *mtd, loff_t ofs, struct mtd_oob_ops *ops) { … } static struct docg3 *sysfs_dev2docg3(struct device *dev, struct device_attribute *attr) { … } static ssize_t dps0_is_key_locked(struct device *dev, struct device_attribute *attr, char *buf) { … } static ssize_t dps1_is_key_locked(struct device *dev, struct device_attribute *attr, char *buf) { … } static ssize_t dps0_insert_key(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { … } static ssize_t dps1_insert_key(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { … } #define FLOOR_SYSFS(id) … static struct device_attribute doc_sys_attrs[DOC_MAX_NBFLOORS][4] = …; static int doc_register_sysfs(struct platform_device *pdev, struct docg3_cascade *cascade) { … } static void doc_unregister_sysfs(struct platform_device *pdev, struct docg3_cascade *cascade) { … } /* * Debug sysfs entries */ static int flashcontrol_show(struct seq_file *s, void *p) { … } DEFINE_SHOW_ATTRIBUTE(…); static int asic_mode_show(struct seq_file *s, void *p) { … } DEFINE_SHOW_ATTRIBUTE(…); static int device_id_show(struct seq_file *s, void *p) { … } DEFINE_SHOW_ATTRIBUTE(…); static int protection_show(struct seq_file *s, void *p) { … } DEFINE_SHOW_ATTRIBUTE(…); static void __init doc_dbg_register(struct mtd_info *floor) { … } /** * doc_set_driver_info - Fill the mtd_info structure and docg3 structure * @chip_id: The chip ID of the supported chip * @mtd: The structure to fill */ static int __init doc_set_driver_info(int chip_id, struct mtd_info *mtd) { … } /** * doc_probe_device - Check if a device is available * @cascade: the cascade of chips this devices will belong to * @floor: the floor of the probed device * @dev: the device * * Checks whether a device at the specified IO range, and floor is available. * * Returns a mtd_info struct if there is a device, ENODEV if none found, ENOMEM * if a memory allocation failed. If floor 0 is checked, a reset of the ASIC is * launched. */ static struct mtd_info * __init doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev) { … } /** * doc_release_device - Release a docg3 floor * @mtd: the device */ static void doc_release_device(struct mtd_info *mtd) { … } /** * docg3_resume - Awakens docg3 floor * @pdev: platfrom device * * Returns 0 (always successful) */ static int docg3_resume(struct platform_device *pdev) { … } /** * docg3_suspend - Put in low power mode the docg3 floor * @pdev: platform device * @state: power state * * Shuts off most of docg3 circuitery to lower power consumption. * * Returns 0 if suspend succeeded, -EIO if chip refused suspend */ static int docg3_suspend(struct platform_device *pdev, pm_message_t state) { … } /** * docg3_probe - Probe the IO space for a DiskOnChip G3 chip * @pdev: platform device * * Probes for a G3 chip at the specified IO space in the platform data * ressources. The floor 0 must be available. * * Returns 0 on success, -ENOMEM, -ENXIO on error */ static int __init docg3_probe(struct platform_device *pdev) { … } /** * docg3_release - Release the driver * @pdev: the platform device * * Returns 0 */ static void docg3_release(struct platform_device *pdev) { … } #ifdef CONFIG_OF static const struct of_device_id docg3_dt_ids[] = …; MODULE_DEVICE_TABLE(of, docg3_dt_ids); #endif static struct platform_driver g3_driver = …; module_platform_driver_probe(…); MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …;
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