[PATCH v4] mtd: rawnand: macronix: OTP access for MX30LFxG18AC
Arseniy Krasnov
avkrasnov at sberdevices.ru
Wed Jun 14 02:24:49 PDT 2023
On 14.06.2023 12:22, Arseniy Krasnov wrote:
> Hello Miquel and Jaime!
>
> On 14.06.2023 12:10, Miquel Raynal wrote:
>> Hi liao,
>>
>> jaimeliao.tw at gmail.com wrote on Wed, 14 Jun 2023 17:06:16 +0800:
>>
>>> Hi Miquel
>>>
>>>
>>>>
>>>> Hello,
>>>>
>>>> AVKrasnov at sberdevices.ru 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
Ahh sorry, there is '_lock_user_prot_reg', it will return EOPNOTSUPP. Now I see:)
Thanks, Arseniy
>
>>
>> Thanks,
>> Miquèl
>>
>>>
>>>>
>>>>>
>>>>> Signed-off-by: Arseniy Krasnov <AVKrasnov at sberdevices.ru>
>>>>> ---
>>>>> 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 at free-electrons.com>
>>>>> */
>>>>>
>>>>> +#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
>>
>>
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