Re: [PATCH v4] mtd: rawnand: macronix: OTP access for MX30LFxG18AC

From: Arseniy Krasnov
Date: Wed Jun 14 2023 - 05:27:38 EST

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In reply to: Miquel Raynal: "Re: [PATCH v4] mtd: rawnand: macronix: OTP access for MX30LFxG18AC"
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Hello Miquel and Jaime!

On 14.06.2023 12:10, Miquel Raynal wrote:
> Hi liao,
>
> jaimeliao.tw@xxxxxxxxx wrote on Wed, 14 Jun 2023 17:06:16 +0800:
>
>> Hi Miquel
>>
>>
>>>
>>> Hello,
>>>
>>> AVKrasnov@xxxxxxxxxxxxxx wrote on Tue, 23 May 2023 13:16:34 +0300:
>>>
>>>> This adds support for OTP area access on MX30LFxG18AC chip series.
>>>
>>> Jaime, any feedback on this? Will you test it?
>>>
>>> How are we supposed to test the OTP is locked? I see this is still an
>>> open point.
>> After checking with internal, sub feature parameter are volatile register.
>>
>> It could be change after enter/exit OTP region or power cycle even OTP
>>
>> region have been locked.
>>
>> OTP operation mode still could be enter/exit and region is read only
>> after OTP in protect mode.
>>
>> #program command could execute but no use after setting OTP region in
>> protect mode.
>>
>> So that we can't check whether OTP region is locked via get feature.
>>
>> And we don't have region for checking status of OTP locked.
>
> Ah, too bad. But thanks a lot for the explanation. Arseniy, can you
> please change your comment to explain that the bit is volatile and thus
> there is no way to check if an otp region is locked? I would return
> EOPNOTSUPP in this case and verify that the core cleanly handles the
> situation.

Ok, thanks for details. @Miquel, ok, I'll change comment from "don't know..."
to this explanation. About EOPNOTSUPP, IIUC I think it is not good way to
suppress '_get_fact_prot_info' and '_get_user_prot_info' callbacks with this
return code as it is the only way to know size of OTP region.

Thanks, Arseniy

>
> Thanks,
> Miquèl
>
>>
>>>
>>>>
>>>> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
>>>> ---
>>>> 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.
>>>> v3 -> v4:
>>>> * Use 'dev_err()' instead of 'WARN()'.
>>>> * Call 'match_string()' before checking 'supports_set_get_features'
>>>> in 'macronix_nand_setup_otp().
>>>> * Use 'u8' instead of 'uint8_t' as ./checkpatch.pl wants.
>>>>
>>>> drivers/mtd/nand/raw/nand_macronix.c | 216 +++++++++++++++++++++++++++
>>>> 1 file changed, 216 insertions(+)
>>>>
>>>> diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
>>>> index 1472f925f386..be1ffa93bebb 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 +331,206 @@ 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. */
>>>> + 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)
>>>> +{
>>>> + u8 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)
>>>> +{
>>>> + u8 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;
>>>> + void *dma_buf;
>>>> + u64 page;
>>>> + 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);
>>>> + if (ret)
>>>> + dev_err(&mtd->dev, "failed to leave OTP mode after %s\n",
>>>> + write ? "write" : "read");
>>>> +
>>>> + 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)
>>>> +{
>>>> + u8 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);
>>>> + if (ret)
>>>> + dev_err(&mtd->dev, "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 (match_string(supported_otp_models,
>>>> + ARRAY_SIZE(supported_otp_models),
>>>> + chip->parameters.model) < 0)
>>>> + return;
>>>> +
>>>> + if (!chip->parameters.supports_set_get_features)
>>>> + return;
>>>> +
>>>> + 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 +540,7 @@ 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
>>
>> Thanks
>> Jaime
>
>

Next message: Jiri Pirko: "Re: [RFC PATCH v8 01/10] dpll: documentation on DPLL subsystem interface"
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In reply to: Miquel Raynal: "Re: [PATCH v4] mtd: rawnand: macronix: OTP access for MX30LFxG18AC"
Next in thread: Arseniy Krasnov: "Re: [PATCH v4] mtd: rawnand: macronix: OTP access for MX30LFxG18AC"
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