linux-kernel - [PATCH 6/7] mtd: spi-nor: Rework the SPI NOR lock/unlock logic

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Date:   Wed, 31 Jul 2019 09:03:37 +0000
From:   <Tudor.Ambarus@...rochip.com>
To:     <boris.brezillon@...labora.com>, <marek.vasut@...il.com>,
        <vigneshr@...com>
CC:     <dwmw2@...radead.org>, <computersforpeace@...il.com>,
        <miquel.raynal@...tlin.com>, <richard@....at>,
        <linux-mtd@...ts.infradead.org>, <linux-kernel@...r.kernel.org>,
        <boris.brezillon@...tlin.com>, <Tudor.Ambarus@...rochip.com>
Subject: [PATCH 6/7] mtd: spi-nor: Rework the SPI NOR lock/unlock logic

From: Boris Brezillon <boris.brezillon@...tlin.com>

Move the locking hooks in a separate struct so that we have just
one field to update when we change the locking implementation.

stm_locking_ops, the legacy locking operations, can be overwritten
later on by implementing manufacturer specific default_init() hooks.

Signed-off-by: Boris Brezillon <boris.brezillon@...tlin.com>
[tudor.ambarus@...rochip.com: use ->default_init() hook]
Signed-off-by: Tudor Ambarus <tudor.ambarus@...rochip.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 37 +++++++++++++++++++------------------
 include/linux/mtd/spi-nor.h   | 14 ++++++++++++++
 2 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index e35aae88d38b..95ca5dd96403 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1743,6 +1743,12 @@ static int stm_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
 	return stm_is_locked_sr(nor, ofs, len, status);
 }
 
+static const struct spi_nor_locking_ops stm_locking_ops = {
+	.lock = stm_lock,
+	.unlock = stm_unlock,
+	.is_locked = stm_is_locked,
+};
+
 static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
@@ -1752,7 +1758,7 @@ static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 	if (ret)
 		return ret;
 
-	ret = nor->flash_lock(nor, ofs, len);
+	ret = nor->locking_ops->lock(nor, ofs, len);
 
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_UNLOCK);
 	return ret;
@@ -1767,7 +1773,7 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 	if (ret)
 		return ret;
 
-	ret = nor->flash_unlock(nor, ofs, len);
+	ret = nor->locking_ops->unlock(nor, ofs, len);
 
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
 	return ret;
@@ -1782,7 +1788,7 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 	if (ret)
 		return ret;
 
-	ret = nor->flash_is_locked(nor, ofs, len);
+	ret = nor->locking_ops->is_locked(nor, ofs, len);
 
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
 	return ret;
@@ -4805,6 +4811,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	nor->quad_enable = spansion_quad_enable;
 	nor->set_4byte = spansion_set_4byte;
 
+	/* Default locking operations. */
+	if (info->flags & SPI_NOR_HAS_LOCK)
+		nor->locking_ops = &stm_locking_ops;
+
 	/* Init flash parameters based on flash_info struct and SFDP */
 	spi_nor_init_params(nor, &params);
 
@@ -4819,21 +4829,6 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	mtd->_read = spi_nor_read;
 	mtd->_resume = spi_nor_resume;
 
-	/* NOR protection support for STmicro/Micron chips and similar */
-	if (JEDEC_MFR(info) == SNOR_MFR_ST ||
-	    JEDEC_MFR(info) == SNOR_MFR_MICRON ||
-	    info->flags & SPI_NOR_HAS_LOCK) {
-		nor->flash_lock = stm_lock;
-		nor->flash_unlock = stm_unlock;
-		nor->flash_is_locked = stm_is_locked;
-	}
-
-	if (nor->flash_lock && nor->flash_unlock && nor->flash_is_locked) {
-		mtd->_lock = spi_nor_lock;
-		mtd->_unlock = spi_nor_unlock;
-		mtd->_is_locked = spi_nor_is_locked;
-	}
-
 	/* sst nor chips use AAI word program */
 	if (info->flags & SST_WRITE)
 		mtd->_write = sst_write;
@@ -4874,6 +4869,12 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	if (info->flags & SPI_NOR_NO_FR)
 		params.hwcaps.mask &= ~SNOR_HWCAPS_READ_FAST;
 
+	if (nor->locking_ops) {
+		mtd->_lock = spi_nor_lock;
+		mtd->_unlock = spi_nor_unlock;
+		mtd->_is_locked = spi_nor_is_locked;
+	}
+
 	/*
 	 * Configure the SPI memory:
 	 * - select op codes for (Fast) Read, Page Program and Sector Erase.
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index a434ab7a53e6..bd68ec5a10e7 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -425,9 +425,23 @@ struct spi_nor {
 	int (*set_4byte)(struct spi_nor *nor, bool enable);
 	int (*clear_sr_bp)(struct spi_nor *nor);
 
+	const struct spi_nor_locking_ops *locking_ops;
+
 	void *priv;
 };
 
+/**
+ * struct spi_nor_locking_ops - SPI NOR locking methods
+ * @lock: lock a region of the SPI NOR
+ * @unlock: unlock a region of the SPI NOR
+ * @is_locked: check if a region of the SPI NOR is completely locked
+ */
+struct spi_nor_locking_ops {
+	int (*lock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
+	int (*unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
+	int (*is_locked)(struct spi_nor *nor, loff_t ofs, uint64_t len);
+};
+
 static u64 __maybe_unused
 spi_nor_region_is_last(const struct spi_nor_erase_region *region)
 {
-- 
2.9.5