[PATCH v6 05/12] spi: intel-dg: implement mtd access handlers

[Alexander Usyskin <alexander.usyskin@intel.com>]

From: Tomas Winkler <tomas.winkler@intel.com>

Implement mtd read, erase, and write handlers.
For erase operation address and size should be 4K aligned.
For write operation address and size has to be 4bytes aligned.

CC: Rodrigo Vivi <rodrigo.vivi@intel.com>
CC: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Vitaly Lubart <vitaly.lubart@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
 drivers/spi/spi-intel-dg.c | 152 +++++++++++++++++++++++++++++++++++--
 1 file changed, 147 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-intel-dg.c b/drivers/spi/spi-intel-dg.c
index a936014f1a76..dfb457c43a5d 100644
--- a/drivers/spi/spi-intel-dg.c
+++ b/drivers/spi/spi-intel-dg.c
@@ -174,7 +174,6 @@ static int intel_dg_spi_is_valid(struct intel_dg_spi *spi)
 	return 0;
 }
 
-__maybe_unused
 static unsigned int spi_get_region(const struct intel_dg_spi *spi, loff_t from)
 {
 	unsigned int i;
@@ -206,7 +205,6 @@ static ssize_t spi_rewrite_partial(struct intel_dg_spi *spi, loff_t to,
 	return len;
 }
 
-__maybe_unused
 static ssize_t spi_write(struct intel_dg_spi *spi, u8 region,
 			 loff_t to, size_t len, const unsigned char *buf)
 {
@@ -265,7 +263,6 @@ static ssize_t spi_write(struct intel_dg_spi *spi, u8 region,
 	return len;
 }
 
-__maybe_unused
 static ssize_t spi_read(struct intel_dg_spi *spi, u8 region,
 			loff_t from, size_t len, unsigned char *buf)
 {
@@ -324,7 +321,6 @@ static ssize_t spi_read(struct intel_dg_spi *spi, u8 region,
 	return len;
 }
 
-__maybe_unused
 static ssize_t
 spi_erase(struct intel_dg_spi *spi, u8 region, loff_t from, u64 len, u64 *fail_addr)
 {
@@ -413,18 +409,164 @@ static int intel_dg_spi_init(struct intel_dg_spi *spi, struct device *device)
 
 static int intel_dg_spi_erase(struct mtd_info *mtd, struct erase_info *info)
 {
-	return 0;
+	struct intel_dg_spi *spi;
+	unsigned int idx;
+	u8 region;
+	u64 addr;
+	ssize_t bytes;
+	loff_t from;
+	size_t len;
+	size_t total_len;
+	int ret = 0;
+
+	if (!mtd || !info)
+		return -EINVAL;
+
+	spi = mtd->priv;
+	if (WARN_ON(!spi))
+		return -EINVAL;
+
+	if (!IS_ALIGNED(info->addr, SZ_4K) || !IS_ALIGNED(info->len, SZ_4K)) {
+		dev_err(&mtd->dev, "unaligned erase %llx %llx\n",
+			info->addr, info->len);
+		info->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
+		return -EINVAL;
+	}
+
+	total_len = info->len;
+	addr = info->addr;
+
+	mutex_lock(&spi->lock);
+
+	while (total_len > 0) {
+		if (!IS_ALIGNED(addr, SZ_4K) || !IS_ALIGNED(total_len, SZ_4K)) {
+			dev_err(&mtd->dev, "unaligned erase %llx %zx\n", addr, total_len);
+			info->fail_addr = addr;
+			ret = -ERANGE;
+			goto out;
+		}
+
+		idx = spi_get_region(spi, addr);
+		if (idx >= spi->nregions) {
+			dev_err(&mtd->dev, "out of range");
+			info->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
+			ret = -ERANGE;
+			goto out;
+		}
+
+		from = addr - spi->regions[idx].offset;
+		region = spi->regions[idx].id;
+		len = total_len;
+		if (len > spi->regions[idx].size - from)
+			len = spi->regions[idx].size - from;
+
+		dev_dbg(&mtd->dev, "erasing region[%d] %s from %llx len %zx\n",
+			region, spi->regions[idx].name, from, len);
+
+		bytes = spi_erase(spi, region, from, len, &info->fail_addr);
+		if (bytes < 0) {
+			dev_dbg(&mtd->dev, "erase failed with %zd\n", bytes);
+			info->fail_addr += spi->regions[idx].offset;
+			ret = bytes;
+			goto out;
+		}
+
+		addr += len;
+		total_len -= len;
+	}
+
+out:
+	mutex_unlock(&spi->lock);
+	return ret;
 }
 
 static int intel_dg_spi_read(struct mtd_info *mtd, loff_t from, size_t len,
 			     size_t *retlen, u_char *buf)
 {
+	struct intel_dg_spi *spi;
+	ssize_t ret;
+	unsigned int idx;
+	u8 region;
+
+	if (!mtd)
+		return -EINVAL;
+
+	spi = mtd->priv;
+	if (WARN_ON(!spi))
+		return -EINVAL;
+
+	idx = spi_get_region(spi, from);
+
+	dev_dbg(&mtd->dev, "reading region[%d] %s from %lld len %zd\n",
+		spi->regions[idx].id, spi->regions[idx].name, from, len);
+
+	if (idx >= spi->nregions) {
+		dev_err(&mtd->dev, "out of ragnge");
+		return -ERANGE;
+	}
+
+	from -= spi->regions[idx].offset;
+	region = spi->regions[idx].id;
+	if (len > spi->regions[idx].size - from)
+		len = spi->regions[idx].size - from;
+
+	mutex_lock(&spi->lock);
+
+	ret = spi_read(spi, region, from, len, buf);
+	if (ret < 0) {
+		dev_dbg(&mtd->dev, "read failed with %zd\n", ret);
+		mutex_unlock(&spi->lock);
+		return ret;
+	}
+
+	*retlen = ret;
+
+	mutex_unlock(&spi->lock);
 	return 0;
 }
 
 static int intel_dg_spi_write(struct mtd_info *mtd, loff_t to, size_t len,
 			      size_t *retlen, const u_char *buf)
 {
+	struct intel_dg_spi *spi;
+	ssize_t ret;
+	unsigned int idx;
+	u8 region;
+
+	if (!mtd)
+		return -EINVAL;
+
+	spi = mtd->priv;
+	if (WARN_ON(!spi))
+		return -EINVAL;
+
+	idx = spi_get_region(spi, to);
+
+	dev_dbg(&mtd->dev, "writing region[%d] %s to %lld len %zd\n",
+		spi->regions[idx].id, spi->regions[idx].name, to, len);
+
+	if (idx >= spi->nregions) {
+		dev_err(&mtd->dev, "out of range");
+		return -ERANGE;
+	}
+
+	to -= spi->regions[idx].offset;
+	region = spi->regions[idx].id;
+	if (len > spi->regions[idx].size - to)
+		len = spi->regions[idx].size - to;
+
+	mutex_lock(&spi->lock);
+
+	ret = spi_write(spi, region, to, len, buf);
+	if (ret < 0) {
+		dev_dbg(&mtd->dev, "write failed with %zd\n", ret);
+		mutex_unlock(&spi->lock);
+		return ret;
+	}
+
+	*retlen = ret;
+
+	mutex_unlock(&spi->lock);
 	return 0;
 }
 
-- 
2.34.1