diff --git a/Documentation/serprog-protocol.txt b/Documentation/serprog-protocol.txt
index a3a4863..d8733cc 100644
--- a/Documentation/serprog-protocol.txt
+++ b/Documentation/serprog-protocol.txt
@@ -33,6 +33,7 @@
 0x12	Set used bustype		8-bit flags (as with 0x05)	ACK / NAK
 0x13	Perform SPI operation		24-bit slen + 24-bit rlen	ACK + rlen bytes of data / NAK
 					 + slen bytes of data
+0x14	Set SPI clock frequency in Hz	32-bit requested frequency	ACK + 32-bit set frequency / NAK
 0x??	unimplemented command - invalid.
 
 
@@ -73,6 +74,14 @@
 		Maximum slen is Q_WRNMAXLEN in case Q_BUSTYPE returns SPI only or S_BUSTYPE was used
 		to set SPI exclusively before. Same for rlen and Q_RDNMAXLEN.
 		This operation is immediate, meaning it doesnt use the operation buffer.
+	0x14 (S_SPI_FREQ):
+		Set the SPI clock frequency. The 32-bit value indicates the
+		requested frequency in Hertz. Value 0 is reserved and should
+		be NAKed by the programmer. The requested frequency should be
+		mapped by the programmer software to a supported frequency
+		lower than the one requested. If there is no lower frequency
+		available the lowest possible should be used. The value
+		chosen is sent back in the reply with an ACK.
 	About mandatory commands:
 		The only truly mandatory commands for any device are 0x00, 0x01, 0x02 and 0x10,
 		but one can't really do anything with these commands.
@@ -107,3 +116,4 @@
 #define S_CMD_Q_RDNMAXLEN	0x11		/* Query read-n maximum length			*/
 #define S_CMD_S_BUSTYPE		0x12		/* Set used bustype(s).				*/
 #define S_CMD_O_SPIOP		0x13		/* Perform SPI operation.			*/
+#define S_CMD_S_SPI_FREQ	0x14		/* Set SPI clock frequency */
diff --git a/flashrom.8 b/flashrom.8
index 93df1a2..f37d5e9 100644
--- a/flashrom.8
+++ b/flashrom.8
@@ -598,7 +598,17 @@
 .sp
 .B "  flashrom \-p serprog:ip=ipaddr:port"
 .sp
-instead. More information about serprog is available in
+instead. In case the device supports it, you can set the SPI clock frequency
+with the optional
+.B spispeed
+parameter. The frequency is parsed as Hertz, unless an
+.BR M ", or " k
+suffix is given, then megahertz or kilohertz are used respectively.
+Example that sets the frequency to 2 MHz:
+.sp
+.B "flashrom \-p serprog:dev=/dev/device:baud,spispeed=2M"
+.sp
+More information about serprog is available in
 .B serprog-protocol.txt
 in the source distribution.
 .SS
diff --git a/serprog.c b/serprog.c
index 3529127..e418c3e 100644
--- a/serprog.c
+++ b/serprog.c
@@ -69,6 +69,7 @@
 #define S_CMD_Q_RDNMAXLEN	0x11	/* Query read-n maximum length			*/
 #define S_CMD_S_BUSTYPE		0x12	/* Set used bustype(s).				*/
 #define S_CMD_O_SPIOP		0x13	/* Perform SPI operation.			*/
+#define S_CMD_S_SPI_FREQ	0x14	/* Set SPI clock frequency			*/
 
 static uint16_t sp_device_serbuf_size = 16;
 static uint16_t sp_device_opbuf_size = 300;
@@ -482,6 +483,7 @@
 	/* Check for the minimum operational set of commands. */
 	if (serprog_buses_supported & BUS_SPI) {
 		uint8_t bt = BUS_SPI;
+		char *spispeed;
 		if (sp_check_commandavail(S_CMD_O_SPIOP) == 0) {
 			msg_perr("Error: SPI operation not supported while the "
 				 "bustype is SPI\n");
@@ -513,6 +515,51 @@
 			spi_programmer_serprog.max_data_read = v;
 			msg_pdbg(MSGHEADER "Maximum read-n length is %d\n", v);
 		}
+		spispeed = extract_programmer_param("spispeed");
+		if (spispeed && strlen(spispeed)) {
+			uint32_t f_spi_req, f_spi;
+			uint8_t buf[4];
+			char *f_spi_suffix;
+
+			errno = 0;
+			f_spi_req = strtol(spispeed, &f_spi_suffix, 0);
+			if (errno != 0 || spispeed == f_spi_suffix) {
+				msg_perr("Error: Could not convert 'spispeed'.\n");
+				return 1;
+			}
+			if (strlen(f_spi_suffix) == 1) {
+				if (!strcasecmp(f_spi_suffix, "M"))
+					f_spi_req *= 1000000;
+				else if (!strcasecmp(f_spi_suffix, "k"))
+					f_spi_req *= 1000;
+				else {
+					msg_perr("Error: Garbage following 'spispeed' value.\n");
+					return 1;
+				}
+			} else if (strlen(f_spi_suffix) > 1) {
+				msg_perr("Error: Garbage following 'spispeed' value.\n");
+				return 1;
+			}
+
+			buf[0] = (f_spi_req >> (0 * 8)) & 0xFF;
+			buf[1] = (f_spi_req >> (1 * 8)) & 0xFF;
+			buf[2] = (f_spi_req >> (2 * 8)) & 0xFF;
+			buf[3] = (f_spi_req >> (3 * 8)) & 0xFF;
+
+			if (sp_check_commandavail(S_CMD_S_SPI_FREQ) == 0)
+				msg_perr(MSGHEADER "Warning: Setting the SPI clock rate is not supported!\n");
+			else if (sp_docommand(S_CMD_S_SPI_FREQ, 4, buf, 4, buf)
+				 == 0) {
+				f_spi = buf[0];
+				f_spi |= buf[1] << (1 * 8);
+				f_spi |= buf[2] << (2 * 8);
+				f_spi |= buf[3] << (3 * 8);
+				msg_pdbg(MSGHEADER "Requested to set SPI clock frequency to %u Hz. "
+					 "It was actually set to %u Hz\n", f_spi_req, f_spi);
+			} else
+				msg_pdbg(MSGHEADER "Setting SPI clock rate to %u Hz failed!\n", f_spi_req);
+		}
+		free(spispeed);
 		bt = serprog_buses_supported;
 		if (sp_docommand(S_CMD_S_BUSTYPE, 1, &bt, 0, NULL))
 			return 1;