drivers/i2c/designware/dw_i2c: return enum cb_err from dw_i2c_init

Using enum cb_err as return type instead of int improves the readability
of the code.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I55e6d93ca141b687871ceaa763bbbbe966c4b4a3
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61511
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Jason Glenesk <jason.glenesk@gmail.com>

src/drivers/i2c/designware/dw_i2c.c

@@ -687,33 +687,33 @@ static enum cb_err dw_i2c_set_speed(unsigned int bus, enum i2c_speed speed,
  * The bus speed can be passed in Hz or using values from device/i2c.h and
  * will default to I2C_SPEED_FAST if it is not provided.
  */
-int dw_i2c_init(unsigned int bus, const struct dw_i2c_bus_config *bcfg)
+enum cb_err dw_i2c_init(unsigned int bus, const struct dw_i2c_bus_config *bcfg)
 {
 	struct dw_i2c_regs *regs;
 	enum i2c_speed speed;
 
 	if (!bcfg)
-		return -1;
+		return CB_ERR;
 
 	speed = bcfg->speed ? : I2C_SPEED_FAST;
 
 	regs = (struct dw_i2c_regs *)dw_i2c_base_address(bus);
 	if (!regs) {
 		printk(BIOS_ERR, "I2C bus %u base address not found\n", bus);
-		return -1;
+		return CB_ERR;
 	}
 
 	if (read32(&regs->comp_type) != DW_I2C_COMP_TYPE) {
 		printk(BIOS_ERR, "I2C bus %u has unknown type 0x%x.\n", bus,
 		       read32(&regs->comp_type));
-		return -1;
+		return CB_ERR;
 	}
 
 	printk(BIOS_DEBUG, "I2C bus %u version 0x%x\n", bus, read32(&regs->comp_version));
 
 	if (dw_i2c_disable(regs) != CB_SUCCESS) {
 		printk(BIOS_ERR, "I2C timeout disabling bus %u\n", bus);
-		return -1;
+		return CB_ERR;
 	}
 
 	/* Put controller in master mode with restart enabled */
@@ -723,7 +723,7 @@ int dw_i2c_init(unsigned int bus, const struct dw_i2c_bus_config *bcfg)
 	/* Set bus speed to FAST by default */
 	if (dw_i2c_set_speed(bus, speed, bcfg) != CB_SUCCESS) {
 		printk(BIOS_ERR, "I2C failed to set speed for bus %u\n", bus);
-		return -1;
+		return CB_ERR;
 	}
 
 	/* Set RX/TX thresholds to smallest values */
@@ -736,7 +736,7 @@ int dw_i2c_init(unsigned int bus, const struct dw_i2c_bus_config *bcfg)
 	printk(BIOS_INFO, "DW I2C bus %u at %p (%u KHz)\n",
 	       bus, regs, speed / KHz);
 
-	return 0;
+	return CB_SUCCESS;
 }
 
 /*

src/drivers/i2c/designware/dw_i2c.h

@@ -95,11 +95,8 @@ uintptr_t dw_i2c_base_address(unsigned int bus);
 
 /*
  * Initialize this bus controller and set the speed
- * Return value:
- * -1 = failure
- *  0 = success
 */
-int dw_i2c_init(unsigned int bus, const struct dw_i2c_bus_config *bcfg);
+enum cb_err dw_i2c_init(unsigned int bus, const struct dw_i2c_bus_config *bcfg);
 
 /*
  * Generate speed config based on clock

src/soc/amd/common/block/i2c/i2c.c

@@ -96,7 +96,7 @@ static void dw_i2c_soc_init(bool is_early_init)
 						cfg->early_init != is_early_init)
 			continue;
 
-		if (dw_i2c_init(bus, cfg)) {
+		if (dw_i2c_init(bus, cfg) != CB_SUCCESS) {
 			printk(BIOS_ERR, "Failed to init i2c bus %u\n", bus);
 			continue;
 		}

src/soc/intel/common/block/i2c/i2c.c

@@ -72,7 +72,7 @@ static int lpss_i2c_early_init_bus(unsigned int bus)
 	lpss_set_power_state(dev, STATE_D0);
 
 	/* Initialize the controller */
-	if (dw_i2c_init(bus, config) < 0) {
+	if (dw_i2c_init(bus, config) != CB_SUCCESS) {
 		printk(BIOS_ERR, "I2C%u failed to initialize\n", bus);
 		return -1;
 	}