[Linaro-mm-sig] Re: [PATCH v4] mtd: rawnand: macronix: OTP access for MX30LFxG18AC

Hello,

AVKrasnov@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.

Signed-off-by: Arseniy Krasnov AVKrasnov@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@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