Hi Mason,
Mason Yang <masonccy...@mxic.com.tw> wrote on Wed, 18 Sep 2019 15:56:26
+0800:
> Macronix AD series support using power down command to
> enter a minimum power consumption state.
>
> MTD default _suspend/_resume function replacement by
> manufacturer postponed initialization.
>
> Signed-off-by: Mason Yang <masonccy...@mxic.com.tw>
> ---
> drivers/mtd/nand/raw/nand_macronix.c | 78
> +++++++++++++++++++++++++++++++++++-
> 1 file changed, 77 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/nand_macronix.c
> b/drivers/mtd/nand/raw/nand_macronix.c
> index 991c636..99a7b2e 100644
> --- a/drivers/mtd/nand/raw/nand_macronix.c
> +++ b/drivers/mtd/nand/raw/nand_macronix.c
> @@ -15,6 +15,8 @@
> #define MXIC_BLOCK_PROTECTION_ALL_LOCK 0x38
> #define MXIC_BLOCK_PROTECTION_ALL_UNLOCK 0x0
>
> +#define NAND_CMD_POWER_DOWN 0xB9
> +
> struct nand_onfi_vendor_macronix {
> u8 reserved;
> u8 reliability_func;
> @@ -78,6 +80,12 @@ static void macronix_nand_onfi_init(struct nand_chip *chip)
> "MX30UF4G28AC",
> };
>
> +static const char * const nand_power_down[] = {
> + "MX30LF1G28AD",
> + "MX30LF2G28AD",
> + "MX30LF4G28AD",
> +};
> +
> static void macronix_nand_fix_broken_get_timings(struct nand_chip *chip)
> {
> unsigned int i;
> @@ -144,8 +152,64 @@ static int mxic_nand_unlock(struct mtd_info *mtd, loff_t
> ofs, uint64_t len)
> return ret;
> }
>
> +int nand_power_down_op(struct nand_chip *chip)
> +{
> + int ret;
> +
> + if (nand_has_exec_op(chip)) {
> + struct nand_op_instr instrs[] = {
> + NAND_OP_CMD(NAND_CMD_POWER_DOWN, 0),
> + };
> +
> + struct nand_operation op = NAND_OPERATION(chip->cur_cs, instrs);
> +
> + ret = nand_exec_op(chip, &op);
> + if (ret)
> + return ret;
> +
> + } else {
> + chip->legacy.cmdfunc(chip, NAND_CMD_POWER_DOWN, -1, -1);
> + }
> +
> + return 0;
> +}
> +
> +static int mxic_nand_suspend(struct mtd_info *mtd)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> +
> + mutex_lock(&chip->lock);
> +
> + nand_select_target(chip, 0);
> + nand_power_down_op(chip);
> + nand_deselect_target(chip);
> +
> + chip->suspend = 1;
> + mutex_unlock(&chip->lock);
> +
> + return 0;
> +}
> +
> +static void mxic_nand_resume(struct mtd_info *mtd)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> +
> + mutex_lock(&chip->lock);
> + // toggle #CS pin to resume NAND device
C++ style comments are forbidden in code.
> + nand_select_target(chip, 0);
On several NAND controllers there is no way to act on the CS line
without actually writing bytes to the NAND chip. So basically this
is very likely to not work.
> + ndelay(20);
Is this delay known somewhere? Is this purely experimental?
> + nand_deselect_target(chip);
> +
> + if (chip->suspend)
> + chip->suspended = 0;
> + else
> + pr_err("%s call for a chip which is not in suspended state\n",
> + __func__);
> + mutex_unlock(&chip->lock);
> +}
> +
> /*
> - * Macronix AC series support using SET/GET_FEATURES to change
> + * Macronix AC and AD series support using SET/GET_FEATURES to change
> * Block Protection and Unprotection.
> *
> * MTD call-back function replacement by manufacturer postponed
> @@ -163,6 +227,18 @@ static void macronix_nand_post_init(struct nand_chip
> *chip)
> }
> }
>
> + for (i = 0; i < ARRAY_SIZE(nand_power_down); i++) {
> + if (!strcmp(nand_power_down[i], chip->parameters.model)) {
> + blockprotected = 1;
> + break;
> + }
> + }
> +
> + if (i < ARRAY_SIZE(nand_power_down)) {
> + mtd->_suspend = mxic_nand_suspend;
> + mtd->_resume = mxic_nand_resume;
> + }
> +
> if (blockprotected && chip->parameters.supports_set_get_features) {
> bitmap_set(chip->parameters.set_feature_list,
> ONFI_FEATURE_ADDR_MXIC_PROTECTION, 1);
Thanks,
Miquèl
