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--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -19,6 +19,7 @@
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/device.h>
+#include <linux/of.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
@@ -32,6 +33,7 @@ struct m25p {
struct spi_device *spi;
struct spi_nor spi_nor;
struct mtd_info mtd;
+ u16 chunk_size;
u8 command[MAX_CMD_SIZE];
};
@@ -157,6 +159,61 @@ static int m25p80_read(struct spi_nor *n
return 0;
}
+static void m25p80_chunked_write(struct spi_nor *nor, loff_t _from, size_t _len,
+ size_t *_retlen, const u_char *_buf)
+{
+ struct m25p *flash = nor->priv;
+ int chunk_size;
+ int retlen = 0;
+
+ chunk_size = flash->chunk_size;
+ if (!chunk_size)
+ chunk_size = _len;
+
+ if (nor->addr_width > 3)
+ chunk_size -= nor->addr_width - 3;
+
+ while (retlen < _len) {
+ size_t len = min_t(int, chunk_size, _len - retlen);
+ const u_char *buf = _buf + retlen;
+ loff_t from = _from + retlen;
+
+ nor->wait_till_ready(nor);
+ nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0, 0);
+
+ m25p80_write(nor, from, len, &retlen, buf);
+ }
+ *_retlen += retlen;
+}
+
+static int m25p80_chunked_read(struct spi_nor *nor, loff_t _from, size_t _len,
+ size_t *_retlen, u_char *_buf)
+{
+ struct m25p *flash = nor->priv;
+ int chunk_size;
+
+ chunk_size = flash->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;
+ int ret = m25p80_read(nor, from, len, &retlen, buf);
+
+ if (ret)
+ return ret;
+
+ *_retlen += retlen;
+ }
+
+ return 0;
+}
+
static int m25p80_erase(struct spi_nor *nor, loff_t offset)
{
struct m25p *flash = nor->priv;
@@ -197,6 +254,7 @@ static int m25p_probe(struct spi_device
struct spi_nor *nor;
enum read_mode mode = SPI_NOR_NORMAL;
char *flash_name = NULL;
+ u32 val;
int ret;
data = dev_get_platdata(&spi->dev);
@@ -244,6 +302,14 @@ static int m25p_probe(struct spi_device
if (ret)
return ret;
+ if (spi->dev.of_node &&
+ !of_property_read_u32(spi->dev.of_node, "m25p,chunked-io", &val)) {
+ dev_warn(&spi->dev, "using chunked io\n");
+ nor->read = m25p80_chunked_read;
+ nor->write = m25p80_chunked_write;
+ flash->chunk_size = val;
+ }
+
ppdata.of_node = spi->dev.of_node;
return mtd_device_parse_register(&flash->mtd, NULL, &ppdata,
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