ft2232_spi: allow 5x clock divisor to be set at runtime
Check at init time whether the chip is a type 'H' (FT2232H or FT4232H).
If not, omit the disable-divide-by-5 (0x8a) command which can confuse
older chips.
Corresponding to flashrom svn r1229.
Signed-off-by: Alex Badea <vamposdecampos@gmail.com>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
diff --git a/ft2232_spi.c b/ft2232_spi.c
index 7c2d9b5..86f3b4a 100644
--- a/ft2232_spi.c
+++ b/ft2232_spi.c
@@ -46,11 +46,11 @@
* The 'H' chips can run internally at either 12MHz or 60MHz.
* The non-H chips can only run at 12MHz.
*/
-#define CLOCK_5X 1
+static uint8_t clock_5x = 1;
/*
* In either case, the divisor is a simple integer clock divider.
- * If CLOCK_5X is set, this divisor divides 30MHz, else it divides 6MHz.
+ * If clock_5x is set, this divisor divides 30MHz, else it divides 6MHz.
*/
#define DIVIDE_BY 3 /* e.g. '3' will give either 10MHz or 2MHz SPI clock. */
@@ -131,6 +131,7 @@
int ft2232_type = FTDI_FT4232H_PID;
enum ftdi_interface ft2232_interface = INTERFACE_B;
char *arg;
+ double mpsse_clk;
arg = extract_programmer_param("type");
if (arg) {
@@ -186,6 +187,12 @@
exit(-1); // TODO
}
+ if (ftdic->type != TYPE_2232H && ftdic->type != TYPE_4232H) {
+ msg_pdbg("FTDI chip type %d is not high-speed\n",
+ ftdic->type);
+ clock_5x = 0;
+ }
+
if (ftdi_set_interface(ftdic, ft2232_interface) < 0) {
msg_perr("Unable to select interface: %s\n",
ftdic->error_str);
@@ -207,18 +214,16 @@
msg_perr("Unable to set bitmode to SPI\n");
}
-#if CLOCK_5X
- msg_pdbg("Disable divide-by-5 front stage\n");
- buf[0] = 0x8a; /* Disable divide-by-5. */
- if (send_buf(ftdic, buf, 1))
- return -1;
-#define MPSSE_CLK 60.0
+ if (clock_5x) {
+ msg_pdbg("Disable divide-by-5 front stage\n");
+ buf[0] = 0x8a; /* Disable divide-by-5. */
+ if (send_buf(ftdic, buf, 1))
+ return -1;
+ mpsse_clk = 60.0;
+ } else {
+ mpsse_clk = 12.0;
+ }
-#else
-
-#define MPSSE_CLK 12.0
-
-#endif
msg_pdbg("Set clock divisor\n");
buf[0] = 0x86; /* command "set divisor" */
/* valueL/valueH are (desired_divisor - 1) */
@@ -227,8 +232,10 @@
if (send_buf(ftdic, buf, 3))
return -1;
- msg_pdbg("SPI clock is %fMHz\n",
- (double)(MPSSE_CLK / (((DIVIDE_BY - 1) + 1) * 2)));
+ msg_pdbg("MPSSE clock: %f MHz divisor: %d "
+ "SPI clock: %f MHz\n",
+ mpsse_clk, DIVIDE_BY,
+ (double)(mpsse_clk / (((DIVIDE_BY - 1) + 1) * 2)));
/* Disconnect TDI/DO to TDO/DI for loopback. */
msg_pdbg("No loopback of TDI/DO TDO/DI\n");