diff options
Diffstat (limited to 'drivers/mtd/nand/raw/davinci_nand.c')
| -rw-r--r-- | drivers/mtd/nand/raw/davinci_nand.c | 408 |
1 files changed, 265 insertions, 143 deletions
diff --git a/drivers/mtd/nand/raw/davinci_nand.c b/drivers/mtd/nand/raw/davinci_nand.c index d975a62caaa5..3986553881d0 100644 --- a/drivers/mtd/nand/raw/davinci_nand.c +++ b/drivers/mtd/nand/raw/davinci_nand.c @@ -10,19 +10,87 @@ * Dirk Behme <Dirk.Behme@gmail.com> */ -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/platform_device.h> +#include <linux/clk.h> #include <linux/err.h> #include <linux/iopoll.h> -#include <linux/mtd/rawnand.h> +#include <linux/kernel.h> +#include <linux/memory/ti-aemif.h> +#include <linux/module.h> #include <linux/mtd/partitions.h> +#include <linux/mtd/rawnand.h> +#include <linux/platform_device.h> +#include <linux/property.h> #include <linux/slab.h> -#include <linux/of_device.h> -#include <linux/of.h> -#include <linux/platform_data/mtd-davinci.h> -#include <linux/platform_data/mtd-davinci-aemif.h> +#define NRCSR_OFFSET 0x00 +#define NANDFCR_OFFSET 0x60 +#define NANDFSR_OFFSET 0x64 +#define NANDF1ECC_OFFSET 0x70 + +/* 4-bit ECC syndrome registers */ +#define NAND_4BIT_ECC_LOAD_OFFSET 0xbc +#define NAND_4BIT_ECC1_OFFSET 0xc0 +#define NAND_4BIT_ECC2_OFFSET 0xc4 +#define NAND_4BIT_ECC3_OFFSET 0xc8 +#define NAND_4BIT_ECC4_OFFSET 0xcc +#define NAND_ERR_ADD1_OFFSET 0xd0 +#define NAND_ERR_ADD2_OFFSET 0xd4 +#define NAND_ERR_ERRVAL1_OFFSET 0xd8 +#define NAND_ERR_ERRVAL2_OFFSET 0xdc + +/* NOTE: boards don't need to use these address bits + * for ALE/CLE unless they support booting from NAND. + * They're used unless platform data overrides them. + */ +#define MASK_ALE 0x08 +#define MASK_CLE 0x10 + +#define MAX_TSU_PS 3000 /* Input setup time in ps */ +#define MAX_TH_PS 1600 /* Input hold time in ps */ + +struct davinci_nand_pdata { + uint32_t mask_ale; + uint32_t mask_cle; + + /* + * 0-indexed chip-select number of the asynchronous + * interface to which the NAND device has been connected. + * + * So, if you have NAND connected to CS3 of DA850, you + * will pass '1' here. Since the asynchronous interface + * on DA850 starts from CS2. + */ + uint32_t core_chipsel; + + /* for packages using two chipselects */ + uint32_t mask_chipsel; + + /* board's default static partition info */ + struct mtd_partition *parts; + unsigned int nr_parts; + + /* none == NAND_ECC_ENGINE_TYPE_NONE (strongly *not* advised!!) + * soft == NAND_ECC_ENGINE_TYPE_SOFT + * on-die == NAND_ECC_ENGINE_TYPE_ON_DIE + * else == NAND_ECC_ENGINE_TYPE_ON_HOST, according to ecc_bits + * + * All DaVinci-family chips support 1-bit hardware ECC. + * Newer ones also support 4-bit ECC, but are awkward + * using it with large page chips. + */ + enum nand_ecc_engine_type engine_type; + enum nand_ecc_placement ecc_placement; + u8 ecc_bits; + + /* e.g. NAND_BUSWIDTH_16 */ + unsigned int options; + /* e.g. NAND_BBT_USE_FLASH */ + unsigned int bbt_options; + + /* Main and mirror bbt descriptor overrides */ + struct nand_bbt_descr *bbt_td; + struct nand_bbt_descr *bbt_md; +}; /* * This is a device driver for the NAND flash controller found on the @@ -56,7 +124,8 @@ struct davinci_nand_info { uint32_t core_chipsel; - struct davinci_aemif_timing *timing; + struct clk *clk; + struct aemif_device *aemif; }; static DEFINE_SPINLOCK(davinci_nand_lock); @@ -168,7 +237,7 @@ static int nand_davinci_correct_1bit(struct nand_chip *chip, u_char *dat, /* * 4-bit hardware ECC ... context maintained over entire AEMIF * - * This is a syndrome engine, but we avoid NAND_ECC_HW_SYNDROME + * This is a syndrome engine, but we avoid NAND_ECC_PLACEMENT_INTERLEAVED * since that forces use of a problematic "infix OOB" layout. * Among other things, it trashes manufacturer bad block markers. * Also, and specific to this hardware, it ECC-protects the "prepad" @@ -371,77 +440,6 @@ correct: return corrected; } -/** - * nand_read_page_hwecc_oob_first - hw ecc, read oob first - * @chip: nand chip info structure - * @buf: buffer to store read data - * @oob_required: caller requires OOB data read to chip->oob_poi - * @page: page number to read - * - * Hardware ECC for large page chips, require OOB to be read first. For this - * ECC mode, the write_page method is re-used from ECC_HW. These methods - * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with - * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from - * the data area, by overwriting the NAND manufacturer bad block markings. - */ -static int nand_davinci_read_page_hwecc_oob_first(struct nand_chip *chip, - uint8_t *buf, - int oob_required, int page) -{ - struct mtd_info *mtd = nand_to_mtd(chip); - int i, eccsize = chip->ecc.size, ret; - int eccbytes = chip->ecc.bytes; - int eccsteps = chip->ecc.steps; - uint8_t *p = buf; - uint8_t *ecc_code = chip->ecc.code_buf; - uint8_t *ecc_calc = chip->ecc.calc_buf; - unsigned int max_bitflips = 0; - - /* Read the OOB area first */ - ret = nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize); - if (ret) - return ret; - - ret = nand_read_page_op(chip, page, 0, NULL, 0); - if (ret) - return ret; - - ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0, - chip->ecc.total); - if (ret) - return ret; - - for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) { - int stat; - - chip->ecc.hwctl(chip, NAND_ECC_READ); - - ret = nand_read_data_op(chip, p, eccsize, false, false); - if (ret) - return ret; - - chip->ecc.calculate(chip, p, &ecc_calc[i]); - - stat = chip->ecc.correct(chip, p, &ecc_code[i], NULL); - if (stat == -EBADMSG && - (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) { - /* check for empty pages with bitflips */ - stat = nand_check_erased_ecc_chunk(p, eccsize, - &ecc_code[i], - eccbytes, NULL, 0, - chip->ecc.strength); - } - - if (stat < 0) { - mtd->ecc_stats.failed++; - } else { - mtd->ecc_stats.corrected += stat; - max_bitflips = max_t(unsigned int, max_bitflips, stat); - } - } - return max_bitflips; -} - /*----------------------------------------------------------------------*/ /* An ECC layout for using 4-bit ECC with small-page flash, storing @@ -490,6 +488,44 @@ static const struct mtd_ooblayout_ops hwecc4_small_ooblayout_ops = { .free = hwecc4_ooblayout_small_free, }; +static int hwecc4_ooblayout_large_ecc(struct mtd_info *mtd, int section, + struct mtd_oob_region *oobregion) +{ + struct nand_device *nand = mtd_to_nanddev(mtd); + unsigned int total_ecc_bytes = nand->ecc.ctx.total; + int nregions = total_ecc_bytes / 10; /* 10 bytes per chunk */ + + if (section >= nregions) + return -ERANGE; + + oobregion->offset = (section * 16) + 6; + oobregion->length = 10; + + return 0; +} + +static int hwecc4_ooblayout_large_free(struct mtd_info *mtd, int section, + struct mtd_oob_region *oobregion) +{ + struct nand_device *nand = mtd_to_nanddev(mtd); + unsigned int total_ecc_bytes = nand->ecc.ctx.total; + int nregions = total_ecc_bytes / 10; /* 10 bytes per chunk */ + + /* First region is used for BBT */ + if (section >= (nregions - 1)) + return -ERANGE; + + oobregion->offset = ((section + 1) * 16); + oobregion->length = 6; + + return 0; +} + +static const struct mtd_ooblayout_ops hwecc4_large_ooblayout_ops = { + .ecc = hwecc4_ooblayout_large_ecc, + .free = hwecc4_ooblayout_large_free, +}; + #if defined(CONFIG_OF) static const struct of_device_id davinci_nand_of_match[] = { {.compatible = "ti,davinci-nand", }, @@ -498,10 +534,10 @@ static const struct of_device_id davinci_nand_of_match[] = { }; MODULE_DEVICE_TABLE(of, davinci_nand_of_match); -static struct davinci_nand_pdata - *nand_davinci_get_pdata(struct platform_device *pdev) +static struct davinci_nand_pdata * +nand_davinci_get_pdata(struct platform_device *pdev) { - if (!dev_get_platdata(&pdev->dev) && pdev->dev.of_node) { + if (!dev_get_platdata(&pdev->dev)) { struct davinci_nand_pdata *pdata; const char *mode; u32 prop; @@ -512,40 +548,44 @@ static struct davinci_nand_pdata pdev->dev.platform_data = pdata; if (!pdata) return ERR_PTR(-ENOMEM); - if (!of_property_read_u32(pdev->dev.of_node, - "ti,davinci-chipselect", &prop)) + if (!device_property_read_u32(&pdev->dev, + "ti,davinci-chipselect", &prop)) pdata->core_chipsel = prop; else return ERR_PTR(-EINVAL); - if (!of_property_read_u32(pdev->dev.of_node, - "ti,davinci-mask-ale", &prop)) + if (!device_property_read_u32(&pdev->dev, + "ti,davinci-mask-ale", &prop)) pdata->mask_ale = prop; - if (!of_property_read_u32(pdev->dev.of_node, - "ti,davinci-mask-cle", &prop)) + if (!device_property_read_u32(&pdev->dev, + "ti,davinci-mask-cle", &prop)) pdata->mask_cle = prop; - if (!of_property_read_u32(pdev->dev.of_node, - "ti,davinci-mask-chipsel", &prop)) + if (!device_property_read_u32(&pdev->dev, + "ti,davinci-mask-chipsel", &prop)) pdata->mask_chipsel = prop; - if (!of_property_read_string(pdev->dev.of_node, - "ti,davinci-ecc-mode", &mode)) { + if (!device_property_read_string(&pdev->dev, + "ti,davinci-ecc-mode", + &mode)) { if (!strncmp("none", mode, 4)) - pdata->ecc_mode = NAND_ECC_NONE; + pdata->engine_type = NAND_ECC_ENGINE_TYPE_NONE; if (!strncmp("soft", mode, 4)) - pdata->ecc_mode = NAND_ECC_SOFT; + pdata->engine_type = NAND_ECC_ENGINE_TYPE_SOFT; if (!strncmp("hw", mode, 2)) - pdata->ecc_mode = NAND_ECC_HW; + pdata->engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST; + if (!strncmp("on-die", mode, 6)) + pdata->engine_type = NAND_ECC_ENGINE_TYPE_ON_DIE; } - if (!of_property_read_u32(pdev->dev.of_node, - "ti,davinci-ecc-bits", &prop)) + if (!device_property_read_u32(&pdev->dev, + "ti,davinci-ecc-bits", &prop)) pdata->ecc_bits = prop; - if (!of_property_read_u32(pdev->dev.of_node, - "ti,davinci-nand-buswidth", &prop) && prop == 16) + if (!device_property_read_u32(&pdev->dev, + "ti,davinci-nand-buswidth", + &prop) && prop == 16) pdata->options |= NAND_BUSWIDTH_16; - if (of_property_read_bool(pdev->dev.of_node, - "ti,davinci-nand-use-bbt")) + if (device_property_read_bool(&pdev->dev, + "ti,davinci-nand-use-bbt")) pdata->bbt_options = NAND_BBT_USE_FLASH; /* @@ -559,17 +599,15 @@ static struct davinci_nand_pdata * then use "ti,davinci-nand" as the compatible in your * device-tree file. */ - if (of_device_is_compatible(pdev->dev.of_node, - "ti,keystone-nand")) { + if (device_is_compatible(&pdev->dev, "ti,keystone-nand")) pdata->options |= NAND_NO_SUBPAGE_WRITE; - } } return dev_get_platdata(&pdev->dev); } #else -static struct davinci_nand_pdata - *nand_davinci_get_pdata(struct platform_device *pdev) +static struct davinci_nand_pdata * +nand_davinci_get_pdata(struct platform_device *pdev) { return dev_get_platdata(&pdev->dev); } @@ -585,21 +623,26 @@ static int davinci_nand_attach_chip(struct nand_chip *chip) if (IS_ERR(pdata)) return PTR_ERR(pdata); - switch (info->chip.ecc.mode) { - case NAND_ECC_NONE: + /* Use board-specific ECC config */ + chip->ecc.engine_type = pdata->engine_type; + chip->ecc.placement = pdata->ecc_placement; + + switch (chip->ecc.engine_type) { + case NAND_ECC_ENGINE_TYPE_NONE: + case NAND_ECC_ENGINE_TYPE_ON_DIE: pdata->ecc_bits = 0; break; - case NAND_ECC_SOFT: + case NAND_ECC_ENGINE_TYPE_SOFT: pdata->ecc_bits = 0; /* - * This driver expects Hamming based ECC when ecc_mode is set - * to NAND_ECC_SOFT. Force ecc.algo to NAND_ECC_HAMMING to - * avoid adding an extra ->ecc_algo field to - * davinci_nand_pdata. + * This driver expects Hamming based ECC when engine_type is set + * to NAND_ECC_ENGINE_TYPE_SOFT. Force ecc.algo to + * NAND_ECC_ALGO_HAMMING to avoid adding an extra ->ecc_algo + * field to davinci_nand_pdata. */ - info->chip.ecc.algo = NAND_ECC_HAMMING; + chip->ecc.algo = NAND_ECC_ALGO_HAMMING; break; - case NAND_ECC_HW: + case NAND_ECC_ENGINE_TYPE_ON_HOST: if (pdata->ecc_bits == 4) { int chunks = mtd->writesize / 512; @@ -624,12 +667,12 @@ static int davinci_nand_attach_chip(struct nand_chip *chip) if (ret == -EBUSY) return ret; - info->chip.ecc.calculate = nand_davinci_calculate_4bit; - info->chip.ecc.correct = nand_davinci_correct_4bit; - info->chip.ecc.hwctl = nand_davinci_hwctl_4bit; - info->chip.ecc.bytes = 10; - info->chip.ecc.options = NAND_ECC_GENERIC_ERASED_CHECK; - info->chip.ecc.algo = NAND_ECC_BCH; + chip->ecc.calculate = nand_davinci_calculate_4bit; + chip->ecc.correct = nand_davinci_correct_4bit; + chip->ecc.hwctl = nand_davinci_hwctl_4bit; + chip->ecc.bytes = 10; + chip->ecc.options = NAND_ECC_GENERIC_ERASED_CHECK; + chip->ecc.algo = NAND_ECC_ALGO_BCH; /* * Update ECC layout if needed ... for 1-bit HW ECC, the @@ -645,21 +688,25 @@ static int davinci_nand_attach_chip(struct nand_chip *chip) mtd_set_ooblayout(mtd, &hwecc4_small_ooblayout_ops); } else if (chunks == 4 || chunks == 8) { - mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops); - info->chip.ecc.read_page = nand_davinci_read_page_hwecc_oob_first; + chip->ecc.read_page = nand_read_page_hwecc_oob_first; + + if (chip->options & NAND_IS_BOOT_MEDIUM) + mtd_set_ooblayout(mtd, &hwecc4_large_ooblayout_ops); + else + mtd_set_ooblayout(mtd, nand_get_large_page_ooblayout()); } else { return -EIO; } } else { /* 1bit ecc hamming */ - info->chip.ecc.calculate = nand_davinci_calculate_1bit; - info->chip.ecc.correct = nand_davinci_correct_1bit; - info->chip.ecc.hwctl = nand_davinci_hwctl_1bit; - info->chip.ecc.bytes = 3; - info->chip.ecc.algo = NAND_ECC_HAMMING; + chip->ecc.calculate = nand_davinci_calculate_1bit; + chip->ecc.correct = nand_davinci_correct_1bit; + chip->ecc.hwctl = nand_davinci_hwctl_1bit; + chip->ecc.bytes = 3; + chip->ecc.algo = NAND_ECC_ALGO_HAMMING; } - info->chip.ecc.size = 512; - info->chip.ecc.strength = pdata->ecc_bits; + chip->ecc.size = 512; + chip->ecc.strength = pdata->ecc_bits; break; default: return -EINVAL; @@ -730,7 +777,7 @@ static int davinci_nand_exec_instr(struct davinci_nand_info *info, case NAND_OP_WAITRDY_INSTR: timeout_us = instr->ctx.waitrdy.timeout_ms * 1000; ret = readl_relaxed_poll_timeout(info->base + NANDFSR_OFFSET, - status, status & BIT(0), 100, + status, status & BIT(0), 5, timeout_us); if (ret) return ret; @@ -738,8 +785,11 @@ static int davinci_nand_exec_instr(struct davinci_nand_info *info, break; } - if (instr->delay_ns) + if (instr->delay_ns) { + /* Dummy read to be sure that command is sent before ndelay starts */ + davinci_nand_readl(info, 0); ndelay(instr->delay_ns); + } return 0; } @@ -767,9 +817,82 @@ static int davinci_nand_exec_op(struct nand_chip *chip, return 0; } +#define TO_CYCLES(ps, period_ns) (DIV_ROUND_UP((ps) / 1000, (period_ns))) + +static int davinci_nand_setup_interface(struct nand_chip *chip, int chipnr, + const struct nand_interface_config *conf) +{ + struct davinci_nand_info *info = to_davinci_nand(nand_to_mtd(chip)); + const struct nand_sdr_timings *sdr; + struct aemif_cs_timings timings; + s32 cfg, min, cyc_ns; + int ret; + + cyc_ns = 1000000000 / clk_get_rate(info->clk); + + sdr = nand_get_sdr_timings(conf); + if (IS_ERR(sdr)) + return PTR_ERR(sdr); + + cfg = TO_CYCLES(sdr->tCLR_min, cyc_ns) - 1; + timings.rsetup = cfg > 0 ? cfg : 0; + + cfg = max_t(s32, TO_CYCLES(sdr->tREA_max + MAX_TSU_PS, cyc_ns), + TO_CYCLES(sdr->tRP_min, cyc_ns)) - 1; + timings.rstrobe = cfg > 0 ? cfg : 0; + + min = TO_CYCLES(sdr->tCEA_max + MAX_TSU_PS, cyc_ns) - 2; + while ((s32)(timings.rsetup + timings.rstrobe) < min) + timings.rstrobe++; + + cfg = TO_CYCLES((s32)(MAX_TH_PS - sdr->tCHZ_max), cyc_ns) - 1; + timings.rhold = cfg > 0 ? cfg : 0; + + min = TO_CYCLES(sdr->tRC_min, cyc_ns) - 3; + while ((s32)(timings.rsetup + timings.rstrobe + timings.rhold) < min) + timings.rhold++; + + cfg = TO_CYCLES((s32)(sdr->tRHZ_max - (timings.rhold + 1) * cyc_ns * 1000), cyc_ns); + cfg = max_t(s32, cfg, TO_CYCLES(sdr->tCHZ_max, cyc_ns)) - 1; + timings.ta = cfg > 0 ? cfg : 0; + + cfg = TO_CYCLES(sdr->tWP_min, cyc_ns) - 1; + timings.wstrobe = cfg > 0 ? cfg : 0; + + cfg = max_t(s32, TO_CYCLES(sdr->tCLS_min, cyc_ns), TO_CYCLES(sdr->tALS_min, cyc_ns)); + cfg = max_t(s32, cfg, TO_CYCLES(sdr->tCS_min, cyc_ns)) - 1; + timings.wsetup = cfg > 0 ? cfg : 0; + + min = TO_CYCLES(sdr->tDS_min, cyc_ns) - 2; + while ((s32)(timings.wsetup + timings.wstrobe) < min) + timings.wstrobe++; + + cfg = max_t(s32, TO_CYCLES(sdr->tCLH_min, cyc_ns), TO_CYCLES(sdr->tALH_min, cyc_ns)); + cfg = max_t(s32, cfg, TO_CYCLES(sdr->tCH_min, cyc_ns)); + cfg = max_t(s32, cfg, TO_CYCLES(sdr->tDH_min, cyc_ns)) - 1; + timings.whold = cfg > 0 ? cfg : 0; + + min = TO_CYCLES(sdr->tWC_min, cyc_ns) - 2; + while ((s32)(timings.wsetup + timings.wstrobe + timings.whold) < min) + timings.whold++; + + dev_dbg(&info->pdev->dev, "RSETUP %x RSTROBE %x RHOLD %x\n", + timings.rsetup, timings.rstrobe, timings.rhold); + dev_dbg(&info->pdev->dev, "TA %x\n", timings.ta); + dev_dbg(&info->pdev->dev, "WSETUP %x WSTROBE %x WHOLD %x\n", + timings.wsetup, timings.wstrobe, timings.whold); + + ret = aemif_check_cs_timings(&timings); + if (ret || chipnr == NAND_DATA_IFACE_CHECK_ONLY) + return ret; + + return aemif_set_cs_timings(info->aemif, info->core_chipsel, &timings); +} + static const struct nand_controller_ops davinci_nand_controller_ops = { .attach_chip = davinci_nand_attach_chip, .exec_op = davinci_nand_exec_op, + .setup_interface = davinci_nand_setup_interface, }; static int nand_davinci_probe(struct platform_device *pdev) @@ -793,7 +916,7 @@ static int nand_davinci_probe(struct platform_device *pdev) return -ENODEV; /* which external chipselect will we be managing? */ - if (pdata->core_chipsel < 0 || pdata->core_chipsel > 3) + if (pdata->core_chipsel > 3) return -ENODEV; info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); @@ -825,9 +948,14 @@ static int nand_davinci_probe(struct platform_device *pdev) return -EADDRNOTAVAIL; } + info->clk = devm_clk_get_enabled(&pdev->dev, "aemif"); + if (IS_ERR(info->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(info->clk), "failed to get clock"); + info->pdev = pdev; info->base = base; info->vaddr = vaddr; + info->aemif = dev_get_drvdata(pdev->dev.parent); mtd = nand_to_mtd(&info->chip); mtd->dev.parent = &pdev->dev; @@ -839,7 +967,6 @@ static int nand_davinci_probe(struct platform_device *pdev) info->chip.options = pdata->options; info->chip.bbt_td = pdata->bbt_td; info->chip.bbt_md = pdata->bbt_md; - info->timing = pdata->timing; info->current_cs = info->vaddr; info->core_chipsel = pdata->core_chipsel; @@ -849,9 +976,6 @@ static int nand_davinci_probe(struct platform_device *pdev) info->mask_ale = pdata->mask_ale ? : MASK_ALE; info->mask_cle = pdata->mask_cle ? : MASK_CLE; - /* Use board-specific ECC config */ - info->chip.ecc.mode = pdata->ecc_mode; - spin_lock_irq(&davinci_nand_lock); /* put CSxNAND into NAND mode */ @@ -890,22 +1014,20 @@ err_cleanup_nand: return ret; } -static int nand_davinci_remove(struct platform_device *pdev) +static void nand_davinci_remove(struct platform_device *pdev) { struct davinci_nand_info *info = platform_get_drvdata(pdev); struct nand_chip *chip = &info->chip; int ret; spin_lock_irq(&davinci_nand_lock); - if (info->chip.ecc.mode == NAND_ECC_HW_SYNDROME) + if (chip->ecc.placement == NAND_ECC_PLACEMENT_INTERLEAVED) ecc4_busy = false; spin_unlock_irq(&davinci_nand_lock); ret = mtd_device_unregister(nand_to_mtd(chip)); WARN_ON(ret); nand_cleanup(chip); - - return 0; } static struct platform_driver nand_davinci_driver = { |