Re: [PATCH] MTD: NAND: pxa3xx_nand: add ability to keep controller settings defined by OBM/bootloader

[Mike Rapoport <mike@compulab.co.il>]

Eric,
Any comments?

Mike Rapoport wrote:
> Signed-off-by: Mike Rapoport <mike@compulab.co.il>
> ---
>  arch/arm/mach-pxa/include/mach/pxa3xx_nand.h |    3 +
>  drivers/mtd/nand/pxa3xx_nand.c               |  103 +++++++++++++++++++++++++-
>  2 files changed, 105 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/mach-pxa/include/mach/pxa3xx_nand.h b/arch/arm/mach-pxa/include/mach/pxa3xx_nand.h
> index eb35fca..3478eae 100644
> --- a/arch/arm/mach-pxa/include/mach/pxa3xx_nand.h
> +++ b/arch/arm/mach-pxa/include/mach/pxa3xx_nand.h
> @@ -49,6 +49,9 @@ struct pxa3xx_nand_platform_data {
>  	 */
>  	int	enable_arbiter;
>  
> +	/* allow platform code to keep OBM/bootloader defined NFC config */
> +	int	keep_config;
> +
>  	const struct mtd_partition		*parts;
>  	unsigned int				nr_parts;
>  
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index ead4a7a..2857a6a 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -171,7 +171,13 @@ static int use_dma = 1;
>  module_param(use_dma, bool, 0444);
>  MODULE_PARM_DESC(use_dma, "enable DMA for data transfering to/from NAND HW");
>  
> -#ifdef CONFIG_MTD_NAND_PXA3xx_BUILTIN
> +/*
> + * Default NAND flash controller configuration setup by the
> + * bootloader. This configuration is used only when pdata->keep_config is set
> + */
> +static struct pxa3xx_nand_timing default_timing;
> +static struct pxa3xx_nand_flash default_flash;
> +
>  static struct pxa3xx_nand_cmdset smallpage_cmdset = {
>  	.read1		= 0x0000,
>  	.read2		= 0x0050,
> @@ -198,6 +204,7 @@ static struct pxa3xx_nand_cmdset largepage_cmdset = {
>  	.lock_status	= 0x007A,
>  };
>  
> +#ifdef CONFIG_MTD_NAND_PXA3xx_BUILTIN
>  static struct pxa3xx_nand_timing samsung512MbX16_timing = {
>  	.tCH	= 10,
>  	.tCS	= 0,
> @@ -297,9 +304,23 @@ static struct pxa3xx_nand_flash *builtin_flash_types[] = {
>  #define NDTR1_tWHR(c)	(min((c), 15) << 4)
>  #define NDTR1_tAR(c)	(min((c), 15) << 0)
>  
> +#define tCH_NDTR0(r)	(((r) >> 19) & 0x7)
> +#define tCS_NDTR0(r)	(((r) >> 16) & 0x7)
> +#define tWH_NDTR0(r)	(((r) >> 11) & 0x7)
> +#define tWP_NDTR0(r)	(((r) >> 8) & 0x7)
> +#define tRH_NDTR0(r)	(((r) >> 3) & 0x7)
> +#define tRP_NDTR0(r)	(((r) >> 0) & 0x7)
> +
> +#define tR_NDTR1(r)	(((r) >> 16) & 0xffff)
> +#define tWHR_NDTR1(r)	(((r) >> 4) & 0xf)
> +#define tAR_NDTR1(r)	(((r) >> 0) & 0xf)
> +
>  /* convert nano-seconds to nand flash controller clock cycles */
>  #define ns2cycle(ns, clk)	(int)(((ns) * (clk / 1000000) / 1000) - 1)
>  
> +/* convert nand flash controller clock cycles to nano-seconds */
> +#define cycle2ns(c, clk)	((((c) + 1) * 1000000 + clk / 500) / (clk / 1000))
> +
>  static void pxa3xx_nand_set_timing(struct pxa3xx_nand_info *info,
>  				   const struct pxa3xx_nand_timing *t)
>  {
> @@ -921,6 +942,82 @@ static int pxa3xx_nand_config_flash(struct pxa3xx_nand_info *info,
>  	return 0;
>  }
>  
> +static void pxa3xx_nand_detect_timing(struct pxa3xx_nand_info *info,
> +				      struct pxa3xx_nand_timing *t)
> +{
> +	unsigned long nand_clk = clk_get_rate(info->clk);
> +	uint32_t ndtr0 = nand_readl(info, NDTR0CS0);
> +	uint32_t ndtr1 = nand_readl(info, NDTR1CS0);
> +
> +	t->tCH = cycle2ns(tCH_NDTR0(ndtr0), nand_clk);
> +	t->tCS = cycle2ns(tCS_NDTR0(ndtr0), nand_clk);
> +	t->tWH = cycle2ns(tWH_NDTR0(ndtr0), nand_clk);
> +	t->tWP = cycle2ns(tWP_NDTR0(ndtr0), nand_clk);
> +	t->tRH = cycle2ns(tRH_NDTR0(ndtr0), nand_clk);
> +	t->tRP = cycle2ns(tRP_NDTR0(ndtr0), nand_clk);
> +
> +	t->tR = cycle2ns(tR_NDTR1(ndtr1), nand_clk);
> +	t->tWHR = cycle2ns(tWHR_NDTR1(ndtr1), nand_clk);
> +	t->tAR = cycle2ns(tAR_NDTR1(ndtr1), nand_clk);
> +}
> +
> +static int pxa3xx_nand_detect_config(struct pxa3xx_nand_info *info)
> +{
> +	uint32_t ndcr = nand_readl(info, NDCR);
> +	struct nand_flash_dev *type = NULL;
> +	uint32_t id = -1;
> +	int i;
> +
> +	default_flash.page_per_block = ndcr & NDCR_PG_PER_BLK ? 64 : 32;
> +	default_flash.page_size = ndcr & NDCR_PAGE_SZ ? 2048 : 512;
> +	default_flash.flash_width = ndcr & NDCR_DWIDTH_M ? 16 : 8;
> +	default_flash.dfc_width = ndcr & NDCR_DWIDTH_C ? 16 : 8;
> +
> +	if (default_flash.page_size == 2048)
> +		default_flash.cmdset = &largepage_cmdset;
> +	else
> +		default_flash.cmdset = &smallpage_cmdset;
> +
> +	/* set info fields needed to __readid */
> +	info->flash_info = &default_flash;
> +	info->read_id_bytes = (default_flash.page_size == 2048) ? 4 : 2;
> +	info->reg_ndcr = ndcr;
> +
> +	if (__readid(info, &id))
> +		return -ENODEV;
> +
> +	/* Lookup the flash id */
> +	id = (id >> 8) & 0xff;		/* device id is byte 2 */
> +	for (i = 0; nand_flash_ids[i].name != NULL; i++) {
> +		if (id == nand_flash_ids[i].id) {
> +			type =  &nand_flash_ids[i];
> +			break;
> +		}
> +	}
> +
> +	if (!type)
> +		return -ENODEV;
> +
> +	/* fill the missing flash information */
> +	i = __ffs(default_flash.page_per_block * default_flash.page_size);
> +	default_flash.num_blocks = type->chipsize << (20 - i);
> +
> +	info->oob_size = (default_flash.page_size == 2048) ? 64 : 16;
> +
> +	/* calculate addressing information */
> +	info->col_addr_cycles = (default_flash.page_size == 2048) ? 2 : 1;
> +
> +	if (default_flash.num_blocks * default_flash.page_per_block > 65536)
> +		info->row_addr_cycles = 3;
> +	else
> +		info->row_addr_cycles = 2;
> +
> +	pxa3xx_nand_detect_timing(info, &default_timing);
> +	default_flash.timing = &default_timing;
> +
> +	return 0;
> +}
> +
>  static int pxa3xx_nand_detect_flash(struct pxa3xx_nand_info *info,
>  				    const struct pxa3xx_nand_platform_data *pdata)
>  {
> @@ -928,6 +1025,10 @@ static int pxa3xx_nand_detect_flash(struct pxa3xx_nand_info *info,
>  	uint32_t id = -1;
>  	int i;
>  
> +	if (pdata->keep_config)
> +		if (pxa3xx_nand_detect_config(info) == 0)
> +			return 0;
> +
>  	for (i = 0; i<pdata->num_flash; ++i) {
>  		f = pdata->flash + i;
>  

-- 
Sincerely yours,
Mike.