Re: [RESEND PATCH v3] mtd: rawnand: macronix: OTP access for MX30LFxG18AC

From: liao jaime
Date: Wed May 24 2023 - 02:33:36 EST


Hi Miquel

>
> Hi Arseniy,
>
> avkrasnov@xxxxxxxxxxxxxx wrote on Mon, 15 May 2023 12:49:50 +0300:
>
> > Hello @Miquel!
> >
> > Sorry, but who could review this patch? :) IIUC this logic is very hw specific and we need
> > someone who knows it well? I tested this patch on our devices (with already known Meson NAND
> > controller).
>
> + Jaime, who might test
>
> >
> > Thanks, Arseniy
> >
> > On 11.05.2023 21:21, Arseniy Krasnov wrote:
> > > Cc: Mason Yang <masonccyang@xxxxxxxxxxx> and Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> > >
> > > On 11.05.2023 18:21, Arseniy Krasnov wrote:
> > >> This adds support for OTP area access on MX30LFxG18AC chip series.
> > >>
> > >> Changelog:
> > >> v1 -> v2:
> > >> * Add slab.h include due to kernel test robot error.
> > >> v2 -> v3:
> > >> * Use 'uint64_t' as input argument for 'do_div()' instead
> > >> of 'unsigned long' due to kernel test robot error.
> > >>
> > >> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
> > >> ---
> > >> drivers/mtd/nand/raw/nand_macronix.c | 213 +++++++++++++++++++++++++++
> > >> 1 file changed, 213 insertions(+)
> > >>
> > >> diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
> > >> index 1472f925f386..2301f990678e 100644
> > >> --- a/drivers/mtd/nand/raw/nand_macronix.c
> > >> +++ b/drivers/mtd/nand/raw/nand_macronix.c
> > >> @@ -6,6 +6,7 @@
> > >> * Author: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
> > >> */
> > >>
> > >> +#include <linux/slab.h>
> > >> #include "linux/delay.h"
> > >> #include "internals.h"
> > >>
> > >> @@ -31,6 +32,20 @@
> > >>
> > >> #define MXIC_CMD_POWER_DOWN 0xB9
> > >>
> > >> +#define ONFI_FEATURE_ADDR_30LFXG18AC_OTP 0x90
> > >> +#define MACRONIX_30LFXG18AC_OTP_START_PAGE 0
> > >> +#define MACRONIX_30LFXG18AC_OTP_PAGES 30
> > >> +#define MACRONIX_30LFXG18AC_OTP_PAGE_SIZE 2112
> > >> +#define MACRONIX_30LFXG18AC_OTP_START_BYTE \
> > >> + (MACRONIX_30LFXG18AC_OTP_START_PAGE * \
> > >> + MACRONIX_30LFXG18AC_OTP_PAGE_SIZE)
> > >> +#define MACRONIX_30LFXG18AC_OTP_SIZE_BYTES \
> > >> + (MACRONIX_30LFXG18AC_OTP_PAGES * \
> > >> + MACRONIX_30LFXG18AC_OTP_PAGE_SIZE)
> > >> +
> > >> +#define MACRONIX_30LFXG18AC_OTP_EN BIT(0)
> > >> +#define MACRONIX_30LFXG18AC_OTP_LOCKED BIT(1)
> > >> +
> > >> struct nand_onfi_vendor_macronix {
> > >> u8 reserved;
> > >> u8 reliability_func;
> > >> @@ -316,6 +331,203 @@ static void macronix_nand_deep_power_down_support(struct nand_chip *chip)
> > >> chip->ops.resume = mxic_nand_resume;
> > >> }
> > >>
> > >> +static int macronix_30lfxg18ac_get_otp_info(struct mtd_info *mtd, size_t len,
> > >> + size_t *retlen,
> > >> + struct otp_info *buf)
> > >> +{
> > >> + if (len < sizeof(*buf))
> > >> + return -EINVAL;
> > >> +
> > >> + /* Don't know how to check that OTP is locked. */
>
> Jaime, any idea?

OTP info could be check by GET_FEATURE command.
GET_FEATURE command with address 90h could read sub-feature
parameter table, P1 is "3" means OTP protection.

Thanks
Jaime

>
> > >> + buf->locked = 0;
> > >> + buf->start = MACRONIX_30LFXG18AC_OTP_START_BYTE;
> > >> + buf->length = MACRONIX_30LFXG18AC_OTP_SIZE_BYTES;
> > >> +
> > >> + *retlen = sizeof(*buf);
> > >> +
> > >> + return 0;
> > >> +}
> > >> +
> > >> +static int macronix_30lfxg18ac_otp_enable(struct nand_chip *nand)
> > >> +{
> > >> + uint8_t feature_buf[ONFI_SUBFEATURE_PARAM_LEN] = { 0 };
> > >> +
> > >> + feature_buf[0] = MACRONIX_30LFXG18AC_OTP_EN;
> > >> + return nand_set_features(nand, ONFI_FEATURE_ADDR_30LFXG18AC_OTP,
> > >> + feature_buf);
> > >> +}
> > >> +
> > >> +static int macronix_30lfxg18ac_otp_disable(struct nand_chip *nand)
> > >> +{
> > >> + uint8_t feature_buf[ONFI_SUBFEATURE_PARAM_LEN] = { 0 };
> > >> +
> > >> + return nand_set_features(nand, ONFI_FEATURE_ADDR_30LFXG18AC_OTP,
> > >> + feature_buf);
> > >> +}
> > >> +
> > >> +static int __macronix_30lfxg18ac_rw_otp(struct mtd_info *mtd,
> > >> + loff_t offs_in_flash,
> > >> + size_t len, size_t *retlen,
> > >> + u_char *buf, bool write)
> > >> +{
> > >> + struct nand_chip *nand;
> > >> + size_t bytes_handled;
> > >> + off_t offs_in_page;
> > >> + uint64_t page;
> > >> + void *dma_buf;
> > >> + int ret;
> > >> +
> > >> + /* 'nand_prog/read_page_op()' may use 'buf' as DMA buffer,
> > >> + * so allocate properly aligned memory for it. This is
> > >> + * needed because cross page accesses may lead to unaligned
> > >> + * buffer address for DMA.
> > >> + */
> > >> + dma_buf = kmalloc(MACRONIX_30LFXG18AC_OTP_PAGE_SIZE, GFP_KERNEL);
> > >> + if (!dma_buf)
> > >> + return -ENOMEM;
> > >> +
> > >> + nand = mtd_to_nand(mtd);
> > >> + nand_select_target(nand, 0);
> > >> +
> > >> + ret = macronix_30lfxg18ac_otp_enable(nand);
> > >> + if (ret)
> > >> + goto out_otp;
> > >> +
> > >> + page = offs_in_flash;
> > >> + /* 'page' will be result of division. */
> > >> + offs_in_page = do_div(page, MACRONIX_30LFXG18AC_OTP_PAGE_SIZE);
> > >> + bytes_handled = 0;
> > >> +
> > >> + while (bytes_handled < len &&
> > >> + page < MACRONIX_30LFXG18AC_OTP_PAGES) {
> > >> + size_t bytes_to_handle;
> > >> +
> > >> + bytes_to_handle = min_t(size_t, len - bytes_handled,
> > >> + MACRONIX_30LFXG18AC_OTP_PAGE_SIZE -
> > >> + offs_in_page);
> > >> +
> > >> + if (write) {
> > >> + memcpy(dma_buf, &buf[bytes_handled], bytes_to_handle);
> > >> + ret = nand_prog_page_op(nand, page, offs_in_page,
> > >> + dma_buf, bytes_to_handle);
> > >> + } else {
> > >> + ret = nand_read_page_op(nand, page, offs_in_page,
> > >> + dma_buf, bytes_to_handle);
> > >> + if (!ret)
> > >> + memcpy(&buf[bytes_handled], dma_buf,
> > >> + bytes_to_handle);
> > >> + }
> > >> + if (ret)
> > >> + goto out_otp;
> > >> +
> > >> + bytes_handled += bytes_to_handle;
> > >> + offs_in_page = 0;
> > >> + page++;
> > >> + }
> > >> +
> > >> + *retlen = bytes_handled;
> > >> +
> > >> +out_otp:
> > >> + if (ret)
> > >> + dev_err(&mtd->dev, "failed to perform OTP IO: %i\n", ret);
> > >> +
> > >> + ret = macronix_30lfxg18ac_otp_disable(nand);
> > >> + WARN(ret, "failed to leave OTP mode after %s\n",
> > >> + write ? "write" : "read");
>
> Let's avoid WARN() calls (none in this driver are relevant IMHO). Just a
> dev_err() should be enough.
>
> > >> + nand_deselect_target(nand);
> > >> + kfree(dma_buf);
> > >> +
> > >> + return ret;
> > >> +}
> > >> +
> > >> +static int macronix_30lfxg18ac_write_otp(struct mtd_info *mtd, loff_t to,
> > >> + size_t len, size_t *rlen,
> > >> + const u_char *buf)
> > >> +{
> > >> + return __macronix_30lfxg18ac_rw_otp(mtd, to, len, rlen, (u_char *)buf,
> > >> + true);
> > >> +}
> > >> +
> > >> +static int macronix_30lfxg18ac_read_otp(struct mtd_info *mtd, loff_t from,
> > >> + size_t len, size_t *rlen,
> > >> + u_char *buf)
> > >> +{
> > >> + return __macronix_30lfxg18ac_rw_otp(mtd, from, len, rlen, buf, false);
> > >> +}
> > >> +
> > >> +static int macronix_30lfxg18ac_lock_otp(struct mtd_info *mtd, loff_t from,
> > >> + size_t len)
> > >> +{
> > >> + uint8_t feature_buf[ONFI_SUBFEATURE_PARAM_LEN] = { 0 };
> > >> + struct nand_chip *nand;
> > >> + int ret;
> > >> +
> > >> + if (from != MACRONIX_30LFXG18AC_OTP_START_BYTE ||
> > >> + len != MACRONIX_30LFXG18AC_OTP_SIZE_BYTES)
> > >> + return -EINVAL;
> > >> +
> > >> + dev_dbg(&mtd->dev, "locking OTP\n");
> > >> +
> > >> + nand = mtd_to_nand(mtd);
> > >> + nand_select_target(nand, 0);
> > >> +
> > >> + feature_buf[0] = MACRONIX_30LFXG18AC_OTP_EN |
> > >> + MACRONIX_30LFXG18AC_OTP_LOCKED;
> > >> + ret = nand_set_features(nand, ONFI_FEATURE_ADDR_30LFXG18AC_OTP,
> > >> + feature_buf);
> > >> + if (ret) {
> > >> + dev_err(&mtd->dev,
> > >> + "failed to lock OTP (set features): %i\n", ret);
> > >> + nand_deselect_target(nand);
> > >> + return ret;
> > >> + }
> > >> +
> > >> + /* Do dummy page prog with zero address. */
> > >> + feature_buf[0] = 0;
> > >> + ret = nand_prog_page_op(nand, 0, 0, feature_buf, 1);
> > >> + if (ret)
> > >> + dev_err(&mtd->dev,
> > >> + "failed to lock OTP (page prog): %i\n", ret);
> > >> +
> > >> + ret = macronix_30lfxg18ac_otp_disable(nand);
> > >> + WARN(ret, "failed to leave OTP mode after lock\n");
> > >> +
> > >> + nand_deselect_target(nand);
> > >> +
> > >> + return ret;
> > >> +}
> > >> +
> > >> +static void macronix_nand_setup_otp(struct nand_chip *chip)
> > >> +{
> > >> + static const char * const supported_otp_models[] = {
> > >> + "MX30LF1G18AC",
> > >> + "MX30LF2G18AC",
> > >> + "MX30LF4G18AC",
> > >> + };
> > >> + struct mtd_info *mtd;
> > >> +
> > >> + if (!chip->parameters.supports_set_get_features)
> > >> + return;
> > >> +
> > >> + if (match_string(supported_otp_models,
> > >> + ARRAY_SIZE(supported_otp_models),
> > >> + chip->parameters.model) < 0)
> > >> + return;
>
> I would start by checking the model, then it's list of supported ops.
>
> > >> +
> > >> + bitmap_set(chip->parameters.get_feature_list,
> > >> + ONFI_FEATURE_ADDR_30LFXG18AC_OTP, 1);
> > >> + bitmap_set(chip->parameters.set_feature_list,
> > >> + ONFI_FEATURE_ADDR_30LFXG18AC_OTP, 1);
> > >> +
> > >> + mtd = nand_to_mtd(chip);
> > >> + mtd->_get_fact_prot_info = macronix_30lfxg18ac_get_otp_info;
> > >> + mtd->_read_fact_prot_reg = macronix_30lfxg18ac_read_otp;
> > >> + mtd->_get_user_prot_info = macronix_30lfxg18ac_get_otp_info;
> > >> + mtd->_read_user_prot_reg = macronix_30lfxg18ac_read_otp;
> > >> + mtd->_write_user_prot_reg = macronix_30lfxg18ac_write_otp;
> > >> + mtd->_lock_user_prot_reg = macronix_30lfxg18ac_lock_otp;
> > >> +}
> > >> +
> > >> static int macronix_nand_init(struct nand_chip *chip)
> > >> {
> > >> if (nand_is_slc(chip))
> > >> @@ -325,6 +537,7 @@ static int macronix_nand_init(struct nand_chip *chip)
> > >> macronix_nand_onfi_init(chip);
> > >> macronix_nand_block_protection_support(chip);
> > >> macronix_nand_deep_power_down_support(chip);
> > >> + macronix_nand_setup_otp(chip);
> > >>
> > >> return 0;
> > >> }
>
>
> Thanks,
> Miquèl