usb_mux/it5205h: implement SBU control

BUG=b:167499422
TEST=able to trigger sbu interrupt on reworked asurada
BRANCH=none

Signed-off-by: Ting Shen <phoenixshen@google.com>
Change-Id: I457596ee938790736ebdd5bfbd22e13831d715b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2402598
Reviewed-by: Eric Yilun Lin <yllin@chromium.org>
Commit-Queue: Ting Shen <phoenixshen@chromium.org>
Tested-by: Ting Shen <phoenixshen@chromium.org>

3 files changed, 73 insertions, 2 deletions

diff --git a/driver/usb_mux/it5205.c b/driver/usb_mux/it5205.c
index 95416547cd..f275568313 100644
--- a/driver/usb_mux/it5205.c
+++ b/driver/usb_mux/it5205.c
@@ -6,10 +6,8 @@
  */
 
 #include "common.h"
-#include "console.h"
 #include "i2c.h"
 #include "it5205.h"
-#include "usb_mux.h"
 #include "util.h"
 
 #define MUX_STATE_DP_USB_MASK (USB_PD_MUX_USB_ENABLED | USB_PD_MUX_DP_ENABLED)
@@ -24,6 +22,20 @@ static int it5205_write(const struct usb_mux *me, uint8_t reg, uint8_t val)
 	return i2c_write8(me->i2c_port, me->i2c_addr_flags, reg, val);
 }
 
+static int it5205h_sbu_update(const struct usb_mux *me, uint8_t reg,
+			      uint8_t mask, enum mask_update_action action)
+{
+	return i2c_update8(me->i2c_port, IT5205H_SBU_I2C_ADDR_FLAGS,
+			   reg, mask, action);
+}
+
+static int it5205h_sbu_field_update(const struct usb_mux *me, uint8_t reg,
+				    uint8_t field_mask, uint8_t set_value)
+{
+	return i2c_field_update8(me->i2c_port, IT5205H_SBU_I2C_ADDR_FLAGS,
+				 reg, field_mask, set_value);
+}
+
 struct mux_chip_id_t {
 	uint8_t chip_id;
 	uint8_t reg;
@@ -54,9 +66,30 @@ static int it5205_init(const struct usb_mux *me)
 			return EC_ERROR_UNKNOWN;
 	}
 
+	if (IS_ENABLED(CONFIG_USB_MUX_IT5205H_SBU_OVP)) {
+		RETURN_ERROR(it5205h_sbu_field_update(me, IT5205H_REG_VSR,
+				IT5205H_VREF_SELECT_MASK,
+				IT5205H_VREF_SELECT_3_3V));
+
+		RETURN_ERROR(it5205h_sbu_field_update(me, IT5205H_REG_CSBUOVPSR,
+				IT5205H_OVP_SELECT_MASK,
+				IT5205H_OVP_3_68V));
+
+		RETURN_ERROR(it5205h_sbu_update(me, IT5205H_REG_ISR,
+				IT5205H_ISR_CSBU_MASK, MASK_CLR));
+
+		RETURN_ERROR(it5205h_enable_csbu_switch(me, true));
+	}
+
 	return EC_SUCCESS;
 }
 
+enum ec_error_list it5205h_enable_csbu_switch(const struct usb_mux *me, bool en)
+{
+	return it5205h_sbu_update(me, IT5205H_REG_CSBUSR,
+			IT5205H_CSBUSR_SWITCH, en ? MASK_SET : MASK_CLR);
+}
+
 /* Writes control register to set switch mode */
 static int it5205_set_mux(const struct usb_mux *me, mux_state_t mux_state)
 {
diff --git a/driver/usb_mux/it5205.h b/driver/usb_mux/it5205.h
index 9e9c4ccfcc..c4fdc6ce49 100644
--- a/driver/usb_mux/it5205.h
+++ b/driver/usb_mux/it5205.h
@@ -8,6 +8,9 @@
 #ifndef __CROS_EC_IT5205_H
 #define __CROS_EC_IT5205_H
 
+#include "stdbool.h"
+#include "usb_mux.h"
+
 /* I2C interface */
 #define IT5205_I2C_ADDR1_FLAGS 0x48
 #define IT5205_I2C_ADDR2_FLAGS 0x58
@@ -31,4 +34,36 @@
 #define IT5205_DP_USB            0x03
 #define IT5205_USB               0x07
 
+
+/* IT5205-H SBU module */
+
+/* I2C address for SBU switch control */
+#define IT5205H_SBU_I2C_ADDR_FLAGS 0x6a
+
+/* Vref Select Register */
+#define IT5205H_REG_VSR            0x10
+#define IT5205H_VREF_SELECT_MASK   0x30
+#define IT5205H_VREF_SELECT_3_3V   0x00
+#define IT5205H_VREF_SELECT_OFF    0x20
+
+/* CSBU OVP Select Register */
+#define IT5205H_REG_CSBUOVPSR      0x1e
+#define IT5205H_OVP_SELECT_MASK    0x30
+#define IT5205H_OVP_3_90V          0x00
+#define IT5205H_OVP_3_68V          0x10
+#define IT5205H_OVP_3_62V          0x20
+#define IT5205H_OVP_3_57V          0x30
+
+/* CSBU Switch Register */
+#define IT5205H_REG_CSBUSR         0x22
+#define IT5205H_CSBUSR_SWITCH      BIT(0)
+
+/* Interrupt Switch Register */
+#define IT5205H_REG_ISR            0x25
+#define IT5205H_ISR_CSBU_MASK      BIT(4)
+#define IT5205H_ISR_CSBU_OVP       BIT(0)
+
+enum ec_error_list it5205h_enable_csbu_switch(const struct usb_mux *me,
+					      bool en);
+
 #endif /* __CROS_EC_IT5205_H */
diff --git a/include/config.h b/include/config.h
index db68f2f8e7..3a6251422d 100644
--- a/include/config.h
+++ b/include/config.h
@@ -4538,6 +4538,9 @@
 /* 'Virtual' USB mux under host (not EC) control */
 #undef CONFIG_USB_MUX_VIRTUAL
 
+/* Enable IT5205H SBU protection switch */
+#undef CONFIG_USB_MUX_IT5205H_SBU_OVP
+
 /*****************************************************************************/
 /* USB GPIO config */
 #undef CONFIG_USB_GPIO