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--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1468,6 +1468,67 @@ write_err:
return ret;
}
+static int spi_nor_chunked_write(struct mtd_info *mtd, loff_t _to, size_t _len,
+ size_t *_retlen, const u_char *_buf)
+{
+ struct spi_nor *nor = mtd_to_spi_nor(mtd);
+ u32 addr_width = nor->addr_width + !!(nor->flags & SNOR_F_4B_EXT_ADDR);
+ int chunk_size;
+ int retlen = 0;
+ int ret;
+
+ chunk_size = nor->chunk_size;
+ if (!chunk_size)
+ chunk_size = _len;
+
+ if (addr_width > 3)
+ chunk_size -= addr_width - 3;
+
+ while (retlen < _len) {
+ size_t len = min_t(int, chunk_size, _len - retlen);
+ const u_char *buf = _buf + retlen;
+ loff_t to = _to + retlen;
+
+ if (nor->flags & SNOR_F_SST)
+ ret = sst_write(mtd, to, len, &retlen, buf);
+ else
+ ret = spi_nor_write(mtd, to, len, &retlen, buf);
+ if (ret)
+ return ret;
+ }
+
+ *_retlen += retlen;
+ return 0;
+}
+
+static int spi_nor_chunked_read(struct mtd_info *mtd, loff_t _from, size_t _len,
+ size_t *_retlen, u_char *_buf)
+{
+ struct spi_nor *nor = mtd_to_spi_nor(mtd);
+ int chunk_size;
+ int ret;
+
+ chunk_size = nor->chunk_size;
+ if (!chunk_size)
+ chunk_size = _len;
+
+ *_retlen = 0;
+ while (*_retlen < _len) {
+ size_t len = min_t(int, chunk_size, _len - *_retlen);
+ u_char *buf = _buf + *_retlen;
+ loff_t from = _from + *_retlen;
+ int retlen = 0;
+
+ ret = spi_nor_read(mtd, from, len, &retlen, buf);
+ if (ret)
+ return ret;
+
+ *_retlen += retlen;
+ }
+
+ return 0;
+}
+
/**
* macronix_quad_enable() - set QE bit in Status Register.
* @nor: pointer to a 'struct spi_nor'
@@ -2826,10 +2887,12 @@ int spi_nor_scan(struct spi_nor *nor, co
}
/* sst nor chips use AAI word program */
- if (info->flags & SST_WRITE)
+ if (info->flags & SST_WRITE) {
mtd->_write = sst_write;
- else
+ nor->flags |= SNOR_F_SST;
+ } else {
mtd->_write = spi_nor_write;
+ }
if (info->flags & USE_FSR)
nor->flags |= SNOR_F_USE_FSR;
@@ -2848,11 +2911,20 @@ int spi_nor_scan(struct spi_nor *nor, co
mtd->writebufsize = nor->page_size;
if (np) {
+ u32 val;
+
/* If we were instantiated by DT, use it */
if (of_property_read_bool(np, "m25p,fast-read"))
params.hwcaps.mask |= SNOR_HWCAPS_READ_FAST;
else
params.hwcaps.mask &= ~SNOR_HWCAPS_READ_FAST;
+
+ if (!of_property_read_u32(np, "m25p,chunked-io", &val)) {
+ dev_info(dev, "using chunked io (size=%d)\n", val);
+ mtd->_read = spi_nor_chunked_read;
+ mtd->_write = spi_nor_chunked_write;
+ nor->chunk_size = val;
+ }
} else {
/* If we weren't instantiated by DT, default to fast-read */
params.hwcaps.mask |= SNOR_HWCAPS_READ_FAST;
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -231,6 +231,7 @@ enum spi_nor_option_flags {
SNOR_F_READY_XSR_RDY = BIT(4),
SNOR_F_USE_CLSR = BIT(5),
SNOR_F_4B_EXT_ADDR = BIT(6),
+ SNOR_F_SST = BIT(7),
};
/**
@@ -272,6 +273,7 @@ struct spi_nor {
struct mutex lock;
struct device *dev;
u32 page_size;
+ size_t chunk_size;
u8 addr_width;
u8 erase_opcode;
u8 read_opcode;
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