[coreboot-gerrit] Change in coreboot[master]: drivers/i2c/dw: Don't try to generate unselected speeds in ACPI table

[Martin Roth (Code Review)]

Martin Roth has submitted this change and it was merged. ( https://review.coreboot.org/c/coreboot/+/34385 )

Change subject: drivers/i2c/dw: Don't try to generate unselected speeds in ACPI table
......................................................................

drivers/i2c/dw: Don't try to generate unselected speeds in ACPI table

When generating entries in SSDT for DesignWare I2C controllers, only
use the speed selected in the devicetree, instead of trying all of them.
This quiets a message which looks like a bug ("dw_i2c: bad counts"),
later on in this driver when checking rise/fall times.

BUG=b:137298661
BRANCH=none
TEST=Boot and verify that I2C controllers still function, and
the nastygram message is gone.

Change-Id: I07207ec95652e8af1a42bfe31214f61a183a134e
Signed-off-by: Tim Wawrzynczak 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34385
Reviewed-by: Furquan Shaikh 
Reviewed-by: Paul Fagerburg 
Tested-by: build bot (Jenkins) 
---
M src/drivers/i2c/designware/dw_i2c.c
1 file changed, 7 insertions(+), 17 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Furquan Shaikh: Looks good to me, approved
  Paul Fagerburg: Looks good to me, approved

diff --git a/src/drivers/i2c/designware/dw_i2c.c b/src/drivers/i2c/designware/dw_i2c.c
index 93b662a..760a735 100644
--- a/src/drivers/i2c/designware/dw_i2c.c
+++ b/src/drivers/i2c/designware/dw_i2c.c
@@ -817,14 +817,9 @@
    const struct dw_i2c_bus_config *bcfg;
    uintptr_t dw_i2c_addr;
    struct dw_i2c_speed_config sgen;
-	enum i2c_speed speeds[DW_I2C_SPEED_CONFIG_COUNT] = {
-		I2C_SPEED_STANDARD,
-		I2C_SPEED_FAST,
-		I2C_SPEED_FAST_PLUS,
-		I2C_SPEED_HIGH,
-	};
-	int i, bus;
+	int bus;
    const char *path;
+	unsigned int speed;

if (!dev->enabled)
    	return;
@@ -847,20 +842,15 @@
    if (!path)
    	return;

-	acpigen_write_scope(path);
+	/* Ensure a default speed is available */
+	speed = (bcfg->speed == 0) ? I2C_SPEED_FAST : bcfg->speed;

/* Report timing values for the OS driver */
-	for (i = 0; i < DW_I2C_SPEED_CONFIG_COUNT; i++) {
-		/* Generate speed config. */
-		if (dw_i2c_gen_speed_config(dw_i2c_addr, speeds[i], bcfg,
-						&sgen) < 0)
-			continue;
-
-		/* Generate ACPI based on selected speed config */
+	if (dw_i2c_gen_speed_config(dw_i2c_addr, speed, bcfg, &sgen) >= 0) {
+		acpigen_write_scope(path);
    	dw_i2c_acpi_write_speed_config(&sgen);
+		acpigen_pop_len();
    }
-
-	acpigen_pop_len();
 }

static int dw_i2c_dev_transfer(struct device *dev,