usb_mux: Add driver support for PS8743 chip

Initial patch for supporting PS8743 USB Type-C
Redriving Switch for USB Host / DisplayPort.

BUG=b:64598680
BRANCH=glkrvp
TEST=On GLKRVP, verify mux setting is correct with
     Apple dongle (VGA + USB) and Pluggable adapter.

Change-Id: Ib45e328fc9ef6ccc410cef4550086be95ef17e8a
Signed-off-by: Divya Sasidharan <divya.s.sasidharan@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/506810
Commit-Ready: Vijay P Hiremath <vijay.p.hiremath@intel.com>
Tested-by: Vijay P Hiremath <vijay.p.hiremath@intel.com>
Reviewed-by: Shawn N <shawnn@chromium.org>

5 files changed, 153 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index 25a2feaa56..b4d2638a57 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -102,6 +102,7 @@ driver-$(CONFIG_USBC_SS_MUX)+=usb_mux.o
 # USB muxes
 driver-$(CONFIG_USB_MUX_PI3USB30532)+=usb_mux_pi3usb30532.o
 driver-$(CONFIG_USB_MUX_PS8740)+=usb_mux_ps8740.o
+driver-$(CONFIG_USB_MUX_PS8743)+=usb_mux_ps8743.o
 driver-$(CONFIG_USB_MUX_VIRTUAL)+=usb_mux_virtual.o
 
 # Firmware Update
diff --git a/driver/ps8743.h b/driver/ps8743.h
new file mode 100644
index 0000000000..1ab516bba4
--- /dev/null
+++ b/driver/ps8743.h
@@ -0,0 +1,40 @@
+/* Copyright 2017 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Parade PS8743 USB Type-C Redriving Switch for USB Host / DisplayPort.
+ */
+
+#ifndef __CROS_EC_PS8743_H
+#define __CROS_EC_PS8743_H
+
+/* Mode register for setting mux */
+#define PS8743_REG_MODE 0x00
+#define PS8743_MODE_POLARITY_INVERTED (1 << 2)
+#define PS8743_MODE_FLIP_PIN_ENABLED  (1 << 3)
+#define PS8743_MODE_USB_ENABLED       (1 << 4)
+#define PS8743_MODE_CE_USB_ENABLED    (1 << 5)
+#define PS8743_MODE_DP_ENABLED        (1 << 6)
+#define PS8743_MODE_CE_DP_ENABLED     (1 << 7)
+/* To reset the state machine to default */
+#define PS8743_MODE_POWER_DOWN    (PS8743_MODE_CE_USB_ENABLED |  \
+				   PS8743_MODE_CE_DP_ENABLED)
+
+/* Status register for checking mux state */
+#define PS8743_REG_STATUS 0x09
+#define PS8743_STATUS_POLARITY_INVERTED (1 << 2)
+#define PS8743_STATUS_USB_ENABLED       (1 << 3)
+#define PS8743_STATUS_DP_ENABLED        (1 << 4)
+#define PS8743_STATUS_HPD_ASSERTED      (1 << 7)
+
+/* Chip ID / revision registers and expected fused values */
+#define PS8743_REG_REVISION_ID1 0xf0
+#define PS8743_REVISION_ID1     0x01
+#define PS8743_REG_REVISION_ID2 0xf1
+#define PS8743_REVISION_ID2     0x0b
+#define PS8743_REG_CHIP_ID1     0xf2
+#define PS8743_CHIP_ID1         0x41
+#define PS8743_REG_CHIP_ID2     0xf3
+#define PS8743_CHIP_ID2         0x87
+
+#endif /* __CROS_EC_PS8743_H */
diff --git a/driver/usb_mux_ps8743.c b/driver/usb_mux_ps8743.c
new file mode 100644
index 0000000000..112bda40ee
--- /dev/null
+++ b/driver/usb_mux_ps8743.c
@@ -0,0 +1,108 @@
+/* Copyright 2017 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Parade PS8743 USB Type-C Redriving Switch for USB Host / DisplayPort.
+ *
+ * TODO: Merge PS8743 & PS8740 as PS874X as both the drivers are almost same.
+ */
+
+#include "common.h"
+#include "i2c.h"
+#include "ps8743.h"
+#include "usb_mux.h"
+#include "util.h"
+
+static inline int ps8743_read(int i2c_addr, uint8_t reg, int *val)
+{
+	return i2c_read8(I2C_PORT_USB_MUX, i2c_addr, reg, val);
+}
+
+static inline int ps8743_write(int i2c_addr, uint8_t reg, uint8_t val)
+{
+	return i2c_write8(I2C_PORT_USB_MUX, i2c_addr, reg, val);
+}
+
+static int ps8743_init(int i2c_addr)
+{
+	int val;
+	int res;
+
+	/* Reset chip back to power-on state */
+	res = ps8743_write(i2c_addr, PS8743_REG_MODE, PS8743_MODE_POWER_DOWN);
+	if (res)
+		return res;
+
+	/*
+	 * Verify revision / chip ID registers.
+	 * From Parade: PS8743 may have REVISION_ID1 as 0 or 1,
+	 * 1 is derived from 0 and have same functionality.
+	 */
+	res = ps8743_read(i2c_addr, PS8743_REG_REVISION_ID1, &val);
+	if (res)
+		return res;
+	if (val <= PS8743_REVISION_ID1)
+		return EC_ERROR_UNKNOWN;
+
+	res = ps8743_read(i2c_addr, PS8743_REG_REVISION_ID2, &val);
+	if (res)
+		return res;
+	if (val != PS8743_REVISION_ID2)
+		return EC_ERROR_UNKNOWN;
+
+	res = ps8743_read(i2c_addr, PS8743_REG_CHIP_ID1, &val);
+	if (res)
+		return res;
+	if (val != PS8743_CHIP_ID1)
+		return EC_ERROR_UNKNOWN;
+
+	res  = ps8743_read(i2c_addr, PS8743_REG_CHIP_ID2, &val);
+	if (res)
+		return res;
+	if (val != PS8743_CHIP_ID2)
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
+/* Writes control register to set switch mode */
+static int ps8743_set_mux(int i2c_addr, mux_state_t mux_state)
+{
+	uint8_t reg = 0;
+
+	if (mux_state & MUX_USB_ENABLED)
+		reg |= PS8743_MODE_USB_ENABLED;
+	if (mux_state & MUX_DP_ENABLED)
+		reg |= PS8743_MODE_DP_ENABLED;
+	if (mux_state & MUX_POLARITY_INVERTED)
+		reg |= PS8743_MODE_POLARITY_INVERTED;
+
+	return ps8743_write(i2c_addr, PS8743_REG_MODE, reg);
+}
+
+/* Reads control register and updates mux_state accordingly */
+static int ps8743_get_mux(int i2c_addr, mux_state_t *mux_state)
+{
+	int reg;
+	int res;
+
+	res = ps8743_read(i2c_addr, PS8743_REG_STATUS, &reg);
+	if (res)
+		return res;
+
+	*mux_state = 0;
+	if (reg & PS8743_STATUS_USB_ENABLED)
+		*mux_state |= MUX_USB_ENABLED;
+	if (reg & PS8743_STATUS_DP_ENABLED)
+		*mux_state |= MUX_DP_ENABLED;
+	if (reg & PS8743_STATUS_POLARITY_INVERTED)
+		*mux_state |= MUX_POLARITY_INVERTED;
+
+	return EC_SUCCESS;
+}
+
+const struct usb_mux_driver ps8743_usb_mux_driver = {
+	.init = ps8743_init,
+	.set = ps8743_set_mux,
+	.get = ps8743_get_mux,
+};
diff --git a/include/config.h b/include/config.h
index bb17f6061e..8bf2f26e75 100644
--- a/include/config.h
+++ b/include/config.h
@@ -2755,6 +2755,9 @@
 /* Support the Parade PS8740 Type-C Redriving Switch */
 #undef CONFIG_USB_MUX_PS8740
 
+/* Support the Parade PS8743 Type-C Redriving Switch */
+#undef CONFIG_USB_MUX_PS8743
+
 /* 'Virtual' USB mux under host (not EC) control */
 #undef CONFIG_USB_MUX_VIRTUAL
 
diff --git a/include/usb_mux.h b/include/usb_mux.h
index 5e1fb6945a..712ed3d437 100644
--- a/include/usb_mux.h
+++ b/include/usb_mux.h
@@ -90,6 +90,7 @@ struct usb_mux {
 /* Supported USB mux drivers */
 extern const struct usb_mux_driver pi3usb30532_usb_mux_driver;
 extern const struct usb_mux_driver ps8740_usb_mux_driver;
+extern const struct usb_mux_driver ps8743_usb_mux_driver;
 extern const struct usb_mux_driver tcpm_usb_mux_driver;
 extern const struct usb_mux_driver virtual_usb_mux_driver;