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Message-ID: <5557BE85.4050208@vanguardiasur.com.ar>
Date: Sat, 16 May 2015 19:02:45 -0300
From: Ezequiel Garcia <ezequiel@...guardiasur.com.ar>
To: Antoine Tenart <antoine.tenart@...e-electrons.com>,
sebastian.hesselbarth@...il.com, dwmw2@...radead.org,
computersforpeace@...il.com
CC: boris.brezillon@...e-electrons.com, zmxu@...vell.com,
jszhang@...vell.com, linux-arm-kernel@...ts.infradead.org,
linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 05/12] mtd: pxa3xx_nand: rework flash detection and
timing setup
Antoine,
On 05/11/2015 11:58 AM, Antoine Tenart wrote:
> Rework the pxa3xx_nand driver to allow using functions exported by the
> nand framework to detect the flash and the timings. Then setup the
> timings using the helpers previously added.
>
> Signed-off-by: Antoine Tenart <antoine.tenart@...e-electrons.com>
> ---
> drivers/mtd/nand/pxa3xx_nand.c | 114 ++++++++++-------------------------------
> 1 file changed, 26 insertions(+), 88 deletions(-)
>
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index b5aad4c46115..6d8d191ee05b 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -1322,48 +1322,25 @@ static int pxa3xx_nand_waitfunc(struct mtd_info *mtd, struct nand_chip *this)
> return NAND_STATUS_READY;
> }
>
> -static int pxa3xx_nand_config_flash(struct pxa3xx_nand_info *info,
> - const struct pxa3xx_nand_flash *f)
> +static int pxa3xx_nand_config_flash(struct pxa3xx_nand_info *info)
> {
> struct platform_device *pdev = info->pdev;
> struct pxa3xx_nand_platform_data *pdata = dev_get_platdata(&pdev->dev);
> struct pxa3xx_nand_host *host = info->host[info->cs];
> + struct mtd_info *mtd = host->mtd;
> + struct nand_chip *chip = mtd->priv;
> uint32_t ndcr = 0x0; /* enable all interrupts */
>
> - if (f->page_size != 2048 && f->page_size != 512) {
> - dev_err(&pdev->dev, "Current only support 2048 and 512 size\n");
> - return -EINVAL;
> - }
> -
> - if (f->flash_width != 16 && f->flash_width != 8) {
> - dev_err(&pdev->dev, "Only support 8bit and 16 bit!\n");
> - return -EINVAL;
> - }
> -
> - /* calculate flash information */
> - host->read_id_bytes = (f->page_size == 2048) ? 4 : 2;
> -
> - /* calculate addressing information */
> - host->col_addr_cycles = (f->page_size == 2048) ? 2 : 1;
> -
> - if (f->num_blocks * f->page_per_block > 65536)
> - host->row_addr_cycles = 3;
> - else
> - host->row_addr_cycles = 2;
> -
> ndcr |= (pdata->enable_arbiter) ? NDCR_ND_ARB_EN : 0;
> ndcr |= (host->col_addr_cycles == 2) ? NDCR_RA_START : 0;
> - ndcr |= (f->page_per_block == 64) ? NDCR_PG_PER_BLK : 0;
> - ndcr |= (f->page_size == 2048) ? NDCR_PAGE_SZ : 0;
> - ndcr |= (f->flash_width == 16) ? NDCR_DWIDTH_M : 0;
> - ndcr |= (f->dfc_width == 16) ? NDCR_DWIDTH_C : 0;
> + ndcr |= (chip->page_shift == 6) ? NDCR_PG_PER_BLK : 0;
> + ndcr |= (mtd->writesize == 2048) ? NDCR_PAGE_SZ : 0;
By the time you call this, there's no detected flash, so there's
no geometry information such as mtd->writesize, chip->page_shift, etc.
>
> ndcr |= NDCR_RD_ID_CNT(host->read_id_bytes);
> ndcr |= NDCR_SPARE_EN; /* enable spare by default */
>
> info->reg_ndcr = ndcr;
>
> - pxa3xx_nand_set_timing(host, f->timing);
> return 0;
> }
>
> @@ -1458,20 +1435,28 @@ static void pxa3xx_nand_free_buff(struct pxa3xx_nand_info *info)
> }
> #endif
>
> -static int pxa3xx_nand_sensing(struct pxa3xx_nand_info *info)
> +static int pxa3xx_nand_sensing(struct pxa3xx_nand_host *host)
> {
> + struct pxa3xx_nand_info *info = host->info_data;
> struct mtd_info *mtd;
> struct nand_chip *chip;
> + const struct nand_sdr_timings *timings;
> int ret;
>
> mtd = info->host[info->cs]->mtd;
> chip = mtd->priv;
>
> - /* use the common timing to make a try */
> - ret = pxa3xx_nand_config_flash(info, &builtin_flash_types[0]);
> + ret = pxa3xx_nand_config_flash(info);
> if (ret)
> return ret;
>
> + /* use the common timing to make a try */
> + timings = onfi_async_timing_mode_to_sdr_timings(0);
> + if (IS_ERR(timings))
> + return PTR_ERR(timings);
> +
> + pxa3xx_nand_set_sdr_timing(host, timings);
> +
> chip->cmdfunc(mtd, NAND_CMD_RESET, 0, 0);
> ret = chip->waitfunc(mtd, chip);
> if (ret & NAND_STATUS_FAIL)
> @@ -1555,12 +1540,8 @@ static int pxa3xx_nand_scan(struct mtd_info *mtd)
> struct pxa3xx_nand_info *info = host->info_data;
> struct platform_device *pdev = info->pdev;
> struct pxa3xx_nand_platform_data *pdata = dev_get_platdata(&pdev->dev);
> - struct nand_flash_dev pxa3xx_flash_ids[2], *def = NULL;
> - const struct pxa3xx_nand_flash *f = NULL;
> struct nand_chip *chip = mtd->priv;
> - uint32_t id = -1;
> - uint64_t chipsize;
> - int i, ret, num;
> + int ret;
> uint16_t ecc_strength, ecc_step;
>
> if (pdata->keep_config && !pxa3xx_nand_detect_config(info))
> @@ -1569,7 +1550,7 @@ static int pxa3xx_nand_scan(struct mtd_info *mtd)
> /* Set a default chunk size */
> info->chunk_size = 512;
>
> - ret = pxa3xx_nand_sensing(info);
> + ret = pxa3xx_nand_sensing(host);
> if (ret) {
> dev_info(&info->pdev->dev, "There is no chip on cs %d!\n",
> info->cs);
> @@ -1577,64 +1558,20 @@ static int pxa3xx_nand_scan(struct mtd_info *mtd)
> return ret;
> }
>
> - chip->cmdfunc(mtd, NAND_CMD_READID, 0, 0);
> - id = *((uint16_t *)(info->data_buff));
> - if (id != 0)
> - dev_info(&info->pdev->dev, "Detect a flash id %x\n", id);
> - else {
> - dev_warn(&info->pdev->dev,
> - "Read out ID 0, potential timing set wrong!!\n");
> -
> - return -EINVAL;
> - }
> -
> - num = ARRAY_SIZE(builtin_flash_types) + pdata->num_flash - 1;
> - for (i = 0; i < num; i++) {
> - if (i < pdata->num_flash)
> - f = pdata->flash + i;
> - else
> - f = &builtin_flash_types[i - pdata->num_flash + 1];
> -
> - /* find the chip in default list */
> - if (f->chip_id == id)
> - break;
> - }
> -
> - if (i >= (ARRAY_SIZE(builtin_flash_types) + pdata->num_flash - 1)) {
> - dev_err(&info->pdev->dev, "ERROR!! flash not defined!!!\n");
> -
> - return -EINVAL;
> - }
> -
> - ret = pxa3xx_nand_config_flash(info, f);
This second call to pxa3xx_nand_config_flash was in charge of re-configuring
the device after proper identification.
I'd say a proper approach is to configure default parameters,
call nand_scan_ident, and finally re-configure using the detected values.
READ_ID should only needs a few parameters to work (e.g. read_id_bytes),
and those are the ones that need an initial default. The rest can remain
null until the device is known.
Regarding read_id_bytes default value, using '4' makes sense and should
work in all cases.
> - if (ret) {
> - dev_err(&info->pdev->dev, "ERROR! Configure failed\n");
> - return ret;
> - }
> -
> - memset(pxa3xx_flash_ids, 0, sizeof(pxa3xx_flash_ids));
> -
> - pxa3xx_flash_ids[0].name = f->name;
> - pxa3xx_flash_ids[0].dev_id = (f->chip_id >> 8) & 0xffff;
> - pxa3xx_flash_ids[0].pagesize = f->page_size;
> - chipsize = (uint64_t)f->num_blocks * f->page_per_block * f->page_size;
> - pxa3xx_flash_ids[0].chipsize = chipsize >> 20;
> - pxa3xx_flash_ids[0].erasesize = f->page_size * f->page_per_block;
> - if (f->flash_width == 16)
> - pxa3xx_flash_ids[0].options = NAND_BUSWIDTH_16;
> - pxa3xx_flash_ids[1].name = NULL;
> - def = pxa3xx_flash_ids;
> KEEP_CONFIG:
> - if (info->reg_ndcr & NDCR_DWIDTH_M)
> - chip->options |= NAND_BUSWIDTH_16;
> -
> /* Device detection must be done with ECC disabled */
> if (info->variant == PXA3XX_NAND_VARIANT_ARMADA370)
> nand_writel(info, NDECCCTRL, 0x0);
>
> - if (nand_scan_ident(mtd, 1, def))
> + if (nand_scan_ident(mtd, 1, NULL))
> return -ENODEV;
>
We only want to configure timings if keep_config is false. Otherwise,
this breaks on platforms that don't have timings and don't support ONFI.
> + ret = pxa3xx_nand_init_timings(host);
> + if (ret) {
> + dev_err(&info->pdev->dev, "Failed to set timings: %d\n", ret);
> + return ret;
> + }
> +
> if (pdata->flash_bbt) {
> /*
> * We'll use a bad block table stored in-flash and don't
> @@ -1732,6 +1669,7 @@ static int alloc_nand_resource(struct platform_device *pdev)
> host->mtd = mtd;
> host->cs = cs;
> host->info_data = info;
> + host->read_id_bytes = 4;
> mtd->priv = host;
> mtd->owner = THIS_MODULE;
>
Aside from this comments, I really like this four patches. They clean most of
the mess and introduce proper timing configuration. In fact, this cleanup
might help removing the keep_config property on mvebu boards.
Thanks for the work,
--
Ezequiel Garcia, VanguardiaSur
www.vanguardiasur.com.ar
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