[PATCH v4 0/3] mtd: spinand: add SPI-NAND MTD resume handler

[PATCH v4 0/3] mtd: spinand: add SPI-NAND MTD resume handler

[patrice.chotard]

From: Patrice Chotard <patrice.chotard@foss.st.com>

Changes in v4:
  - Add spinand_init_flash helper()
  - Remove no more needed spinand_block_unlock() helper introduced in v2	

Changes in v3:
  - Add spinand_read_cfg() helper 
  - Add spinand_read_cfg() call to repopulate cache during resume
  - Split v2 patch in 3 patches

Changes in v2:
  - Add helper spinand_block_unlock().
  - Add spinand_ecc_enable() call.
  - Remove some dev_err().
  - Fix commit's title and message.

Patrice Chotard (3):
  mtd: spinand: Add spinand_init_flash() helper
  mtd: spinand: add spinand_read_cfg() helper
  mtd: spinand: add SPI-NAND MTD resume handler

 drivers/mtd/nand/spi/core.c | 113 +++++++++++++++++++++++++-----------
 1 file changed, 79 insertions(+), 34 deletions(-)

-- 
2.17.1

[PATCH v4 1/3] mtd: spinand: Add spinand_init_flash() helper

[patrice.chotard]

From: Patrice Chotard <patrice.chotard@foss.st.com>

Add spinand_init_flash() helper which implements
all needed init for future SPI-NAND resume ops.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
---
 drivers/mtd/nand/spi/core.c | 66 +++++++++++++++++++++++--------------
 1 file changed, 41 insertions(+), 25 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 17f63f95f4a2..1f39a38fbf69 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1074,12 +1074,51 @@ static int spinand_detect(struct spinand_device *spinand)
 	return 0;
 }
 
+static int spinand_init_flash(struct spinand_device *spinand)
+{
+	struct device *dev = &spinand->spimem->spi->dev;
+	struct nand_device *nand = spinand_to_nand(spinand);
+	int ret, i;
+
+	ret = spinand_init_quad_enable(spinand);
+	if (ret)
+		return ret;
+
+	ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0);
+	if (ret)
+		return ret;
+
+	ret = spinand_manufacturer_init(spinand);
+	if (ret) {
+		dev_err(dev,
+		"Failed to initialize the SPI NAND chip (err = %d)\n",
+		ret);
+		return ret;
+	}
+
+	/* After power up, all blocks are locked, so unlock them here. */
+	for (i = 0; i < nand->memorg.ntargets; i++) {
+		ret = spinand_select_target(spinand, i);
+		if (ret)
+			break;
+
+		ret = spinand_lock_block(spinand, BL_ALL_UNLOCKED);
+		if (ret)
+			break;
+	}
+
+	if (ret)
+		spinand_manufacturer_cleanup(spinand);
+
+	return ret;
+}
+
 static int spinand_init(struct spinand_device *spinand)
 {
 	struct device *dev = &spinand->spimem->spi->dev;
 	struct mtd_info *mtd = spinand_to_mtd(spinand);
 	struct nand_device *nand = mtd_to_nanddev(mtd);
-	int ret, i;
+	int ret;
 
 	/*
 	 * We need a scratch buffer because the spi_mem interface requires that
@@ -1112,22 +1151,10 @@ static int spinand_init(struct spinand_device *spinand)
 	if (ret)
 		goto err_free_bufs;
 
-	ret = spinand_init_quad_enable(spinand);
+	ret = spinand_init_flash(spinand);
 	if (ret)
 		goto err_free_bufs;
 
-	ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0);
-	if (ret)
-		goto err_free_bufs;
-
-	ret = spinand_manufacturer_init(spinand);
-	if (ret) {
-		dev_err(dev,
-			"Failed to initialize the SPI NAND chip (err = %d)\n",
-			ret);
-		goto err_free_bufs;
-	}
-
 	ret = spinand_create_dirmaps(spinand);
 	if (ret) {
 		dev_err(dev,
@@ -1136,17 +1163,6 @@ static int spinand_init(struct spinand_device *spinand)
 		goto err_manuf_cleanup;
 	}
 
-	/* After power up, all blocks are locked, so unlock them here. */
-	for (i = 0; i < nand->memorg.ntargets; i++) {
-		ret = spinand_select_target(spinand, i);
-		if (ret)
-			goto err_manuf_cleanup;
-
-		ret = spinand_lock_block(spinand, BL_ALL_UNLOCKED);
-		if (ret)
-			goto err_manuf_cleanup;
-	}
-
 	ret = nanddev_init(nand, &spinand_ops, THIS_MODULE);
 	if (ret)
 		goto err_manuf_cleanup;
-- 
2.17.1

[PATCH v4 2/3] mtd: spinand: add spinand_read_cfg() helper

[patrice.chotard]

From: Patrice Chotard <patrice.chotard@foss.st.com>

Put REG_CFG reading code in spinand_read_cfg().
This function will be needed by the future SPI-NAND resume ops.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
---
Changes in v4:
  - None

 drivers/mtd/nand/spi/core.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 1f39a38fbf69..58945f0ae839 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -138,20 +138,13 @@ int spinand_select_target(struct spinand_device *spinand, unsigned int target)
 	return 0;
 }
 
-static int spinand_init_cfg_cache(struct spinand_device *spinand)
+static int spinand_read_cfg(struct spinand_device *spinand)
 {
 	struct nand_device *nand = spinand_to_nand(spinand);
-	struct device *dev = &spinand->spimem->spi->dev;
+
 	unsigned int target;
 	int ret;
 
-	spinand->cfg_cache = devm_kcalloc(dev,
-					  nand->memorg.ntargets,
-					  sizeof(*spinand->cfg_cache),
-					  GFP_KERNEL);
-	if (!spinand->cfg_cache)
-		return -ENOMEM;
-
 	for (target = 0; target < nand->memorg.ntargets; target++) {
 		ret = spinand_select_target(spinand, target);
 		if (ret)
@@ -170,6 +163,21 @@ static int spinand_init_cfg_cache(struct spinand_device *spinand)
 	return 0;
 }
 
+static int spinand_init_cfg_cache(struct spinand_device *spinand)
+{
+	struct nand_device *nand = spinand_to_nand(spinand);
+	struct device *dev = &spinand->spimem->spi->dev;
+
+	spinand->cfg_cache = devm_kcalloc(dev,
+					  nand->memorg.ntargets,
+					  sizeof(*spinand->cfg_cache),
+					  GFP_KERNEL);
+	if (!spinand->cfg_cache)
+		return -ENOMEM;
+
+	return spinand_read_cfg(spinand);
+}
+
 static int spinand_init_quad_enable(struct spinand_device *spinand)
 {
 	bool enable = false;
-- 
2.17.1

[PATCH v4 3/3] mtd: spinand: add SPI-NAND MTD resume handler

[patrice.chotard]

From: Patrice Chotard <patrice.chotard@foss.st.com>

After power up, all SPI NAND's blocks are locked. Only read operations
are allowed, write and erase operations are forbidden.
The SPI NAND framework unlocks all the blocks during its initialization.

During a standby low power, the memory is powered down, losing its
configuration.
During the resume, the QSPI driver state is restored but the SPI NAND
framework does not reconfigured the memory.

This patch adds SPI-NAND MTD PM handlers for resume ops.
SPI NAND resume op re-initializes SPI NAND flash to its probed state.

Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
---
Changes in v4:
  - Call spinand_init_flash() helper in spinand_mtd_resume()

Changes in v3:
  - Add spinand_read_cfg() call to repopulate cache

Changes in v2:
  - Add helper spinand_block_unlock().
  - Add spinand_ecc_enable() call.
  - Remove some dev_err().
  - Fix commit's title and message.

 drivers/mtd/nand/spi/core.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 58945f0ae839..e108e6176f64 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1121,6 +1121,26 @@ static int spinand_init_flash(struct spinand_device *spinand)
 	return ret;
 }
 
+static void spinand_mtd_resume(struct mtd_info *mtd)
+{
+	struct spinand_device *spinand = mtd_to_spinand(mtd);
+	int ret;
+
+	ret = spinand_reset_op(spinand);
+	if (ret)
+		return;
+
+	ret = spinand_read_cfg(spinand);
+	if (ret)
+		return;
+
+	ret = spinand_init_flash(spinand);
+	if (ret)
+		return;
+
+	spinand_ecc_enable(spinand, false);
+}
+
 static int spinand_init(struct spinand_device *spinand)
 {
 	struct device *dev = &spinand->spimem->spi->dev;
@@ -1191,6 +1211,7 @@ static int spinand_init(struct spinand_device *spinand)
 	mtd->_block_isreserved = spinand_mtd_block_isreserved;
 	mtd->_erase = spinand_mtd_erase;
 	mtd->_max_bad_blocks = nanddev_mtd_max_bad_blocks;
+	mtd->_resume = spinand_mtd_resume;
 
 	if (nand->ecc.engine) {
 		ret = mtd_ooblayout_count_freebytes(mtd);
-- 
2.17.1