dummyflasher.c: Upstream ChromiumOS 'freq' param feature

This allows the dummyflasher to emulate a bus/chip frequency
by passing a delay parameter.

BUG=b:140394053
BRANCH=none
TEST=builds and ran with freq passed,
```
   └──╼ dd if=/dev/urandom of=/tmp/bar bs=2K count=1
   1+0 records in
   1+0 records out
   2048 bytes (2.0 kB, 2.0 KiB) copied, 0.000583308 s, 3.5 MB/s

   └──╼ ./flashrom -p dummy:image=/tmp/foo,bus=spi,freq=100Hz,size=2048,emulate=VARIABLE_SIZE -w /tmp/bar
   flashrom v1.2-105-g702c58a-dirty on Linux 5.7.10-1rodete2-amd64 (x86_64)
   flashrom is free software, get the source code at https://flashrom.org

   Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
   Found Generic flash chip "Variable Size SPI chip" (2 kB, SPI) on dummy.
   Reading old flash chip contents... done.
   Erasing and writing flash chip... Erase/write done.
   Verifying flash... VERIFIED.
```

Change-Id: I1c2702b9e0cae860f5f03114e307707d4d3219af
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/45461
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sam McNally <sammc@google.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/dummyflasher.c b/dummyflasher.c
index 89e8ba43e..6426ad2ed 100644
--- a/dummyflasher.c
+++ b/dummyflasher.c
@@ -54,6 +54,9 @@ struct emu_data {
 	unsigned int emu_chip_size;
 	int emu_modified;	/* is the image modified since reading it? */
 	uint8_t emu_status;
+	/* If "freq" parameter is passed in from command line, commands will delay
+	 * for this period before returning. */
+	unsigned long int delay_us;
 	unsigned int emu_max_byteprogram_size;
 	unsigned int emu_max_aai_size;
 	unsigned int emu_jedec_se_size;
@@ -175,6 +178,7 @@ int dummy_init(void)
 		return 1;
 	}
 	data->emu_chip = EMULATE_NONE;
+	data->delay_us = 0;
 	spi_master_dummyflasher.data = data;
 
 	msg_pspew("%s\n", __func__);
@@ -289,6 +293,52 @@ int dummy_init(void)
 	}
 	free(tmp);
 
+	/* frequency to emulate in Hz (default), KHz, or MHz */
+	tmp = extract_programmer_param("freq");
+	if (tmp) {
+		unsigned long int freq;
+		char *units = tmp;
+		char *end = tmp + strlen(tmp);
+
+		errno = 0;
+		freq = strtoul(tmp, &units, 0);
+		if (errno) {
+			msg_perr("Invalid frequency \"%s\", %s\n",
+					tmp, strerror(errno));
+			free(tmp);
+			return 1;
+		}
+
+		if ((units > tmp) && (units < end)) {
+			int units_valid = 0;
+
+			if (units < end - 3) {
+				;
+			} else if (units == end - 2) {
+				if (!strcasecmp(units, "hz"))
+					units_valid = 1;
+			} else if (units == end - 3) {
+				if (!strcasecmp(units, "khz")) {
+					freq *= 1000;
+					units_valid = 1;
+				} else if (!strcasecmp(units, "mhz")) {
+					freq *= 1000000;
+					units_valid = 1;
+				}
+			}
+
+			if (!units_valid) {
+				msg_perr("Invalid units: %s\n", units);
+				free(tmp);
+				return 1;
+			}
+		}
+
+		/* Assume we only work with bytes and transfer at 1 bit/Hz */
+		data->delay_us = (1000000 * 8) / freq;
+	}
+	free(tmp);
+
 #if EMULATE_CHIP
 #if EMULATE_SPI_CHIP
 	tmp = extract_programmer_param("size");
@@ -963,6 +1013,8 @@ static int dummy_spi_send_command(const struct flashctx *flash, unsigned int wri
 	for (i = 0; i < readcnt; i++)
 		msg_pspew(" 0x%02x", readarr[i]);
 	msg_pspew("\n");
+
+	programmer_delay((writecnt + readcnt) * emu_data->delay_us);
 	return 0;
 }