Every SPI host controller implemented its own way to read flash chips

This was partly due to a design problem in the abstraction layer.

There should be exactly two different functions for reading SPI chips:
- memory mapped reads
- SPI command reads.

Each of them should be contained in a separate function, optionally
taking parameters where needed.

This patch solves the problems mentioned above, shortens the code and
makes the code logic a lot more obvious.

Since open-coding the min() function leads to errors, include it in this
patch as well.

Corresponding to flashrom svn r589.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/flash.h b/flash.h
index aa97c19..1b798af 100644
--- a/flash.h
+++ b/flash.h
@@ -721,6 +721,7 @@
 #define printf_debug(x...) { if (verbose) printf(x); }
 void map_flash_registers(struct flashchip *flash);
 int read_memmapped(struct flashchip *flash, uint8_t *buf);
+int min(int a, int b);
 extern char *pcidev_bdf;
 
 /* layout.c */
@@ -768,6 +769,7 @@
 void spi_byte_program(int address, uint8_t byte);
 int spi_nbyte_program(int address, uint8_t *bytes, int len);
 int spi_nbyte_read(int address, uint8_t *bytes, int len);
+int spi_read_chunked(struct flashchip *flash, uint8_t *buf, int chunksize);
 int spi_aai_write(struct flashchip *flash, uint8_t *buf);
 uint32_t spi_get_valid_read_addr(void);