sf: Add flag status register polling support

Flag status register polling is required for micron 512Mb flash
devices onwards, for performing erase/program operations.

Like polling for WIP(Write-In-Progress) bit in read status register,
spi_flash_cmd_wait_ready will poll for PEC(Program-Erase-Control)
bit in flag status register.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Jagannadha Sutradharudu Teki 2013-06-21 15:56:30 +05:30
parent ba549de6c5
commit 615a156167
4 changed files with 21 additions and 4 deletions

View file

@ -200,12 +200,19 @@ int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long timeout)
unsigned long timebase;
int ret;
u8 status;
u8 check_status = 0x0;
u8 poll_bit = STATUS_WIP;
u8 cmd = CMD_READ_STATUS;
u8 cmd = flash->poll_cmd;
if (cmd == CMD_FLAG_STATUS) {
poll_bit = STATUS_PEC;
check_status = poll_bit;
}
ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN);
if (ret) {
debug("SF: Failed to send command %02x: %d\n", cmd, ret);
debug("SF: fail to read %s status register\n",
cmd == CMD_READ_STATUS ? "read" : "flag");
return ret;
}
@ -217,14 +224,14 @@ int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long timeout)
if (ret)
return -1;
if ((status & poll_bit) == 0)
if ((status & poll_bit) == check_status)
break;
} while (get_timer(timebase) < timeout);
spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
if ((status & poll_bit) == 0)
if ((status & poll_bit) == check_status)
return 0;
/* Timed out */
@ -584,6 +591,7 @@ void *spi_flash_do_alloc(int offset, int size, struct spi_slave *spi,
/* Set up some basic fields - caller will sort out sizes */
flash->spi = spi;
flash->name = name;
flash->poll_cmd = CMD_READ_STATUS;
flash->read = spi_flash_cmd_read_fast;
flash->write = spi_flash_cmd_write_multi;

View file

@ -22,6 +22,7 @@
#define CMD_PAGE_PROGRAM 0x02
#define CMD_WRITE_DISABLE 0x04
#define CMD_READ_STATUS 0x05
#define CMD_FLAG_STATUS 0x70
#define CMD_WRITE_ENABLE 0x06
#define CMD_ERASE_4K 0x20
#define CMD_ERASE_32K 0x52
@ -45,6 +46,7 @@
/* Common status */
#define STATUS_WIP 0x01
#define STATUS_PEC 0x80
/* Send a single-byte command to the device and read the response */
int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t len);

View file

@ -210,5 +210,9 @@ struct spi_flash *spi_flash_probe_stmicro(struct spi_slave *spi, u8 * idcode)
flash->sector_size = 256 * params->pages_per_sector;
flash->size = flash->sector_size * params->nr_sectors;
/* for >= 512MiB flashes, use flag status instead of read_status */
if (flash->size >= 0x4000000)
flash->poll_cmd = CMD_FLAG_STATUS;
return flash;
}

View file

@ -46,6 +46,9 @@ struct spi_flash {
/* Current flash bank */
u8 bank_curr;
#endif
/* Poll cmd - for flash erase/program */
u8 poll_cmd;
void *memory_map; /* Address of read-only SPI flash access */
int (*read)(struct spi_flash *flash, u32 offset,
size_t len, void *buf);