Change in flashrom[master]: lspcon: restart MPU on programmer shutdown

[Peter Marheine (Code Review)]

Peter Marheine has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/55403 )

Change subject: lspcon: restart MPU on programmer shutdown
......................................................................

lspcon: restart MPU on programmer shutdown

Programmer initialization stops the on-chip MPU, and it was never
restarted. Leaving it stopped seems to prevent some display detection
from working, so implement restarting the MPU on programmer shutdown.

BUG=b:190359231
TEST=display hotplug works reliably after device communication

Change-Id: I66cd68f8f6905a2bfaf5b085bf08dcb218f42855
---
M lspcon_i2c_spi.c
1 file changed, 12 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/03/55403/1

diff --git a/lspcon_i2c_spi.c b/lspcon_i2c_spi.c
index 9f3bb9a..f8df9e4 100644
--- a/lspcon_i2c_spi.c
+++ b/lspcon_i2c_spi.c
@@ -327,6 +327,16 @@
    return ret;
 }

+static int lspcon_i2c_spi_start_mpu(int fd)
+{
+	int ret;
+	// Assert reset
+	if ((ret = lspcon_i2c_spi_write_register(fd, MPU, 0xc0)) != 0)
+		return ret;
+	// Release reset and start MPU
+	return lspcon_i2c_spi_write_register(fd, MPU, 0);
+}
+
 static int lspcon_i2c_spi_map_page(int fd, unsigned int offset)
 {
    int ret = 0;
@@ -418,15 +428,16 @@
    .write_aai = lspcon_i2c_spi_write_aai,
 };

-/* TODO: MPU still stopped at this point, probably need to reset it. */
 static int lspcon_i2c_spi_shutdown(void *data)
 {
    int ret = 0;
         struct lspcon_i2c_spi_data *lspcon_data =
    	(struct lspcon_i2c_spi_data *)data;
    int fd = lspcon_data->fd;
+
    ret |= lspcon_i2c_spi_enable_write_protection(fd);
    ret |= lspcon_i2c_spi_toggle_register_protection(fd, 0);
+	ret |= lspcon_i2c_spi_start_mpu(fd);
    i2c_close(fd);
    free(data);