usb_mux: Add driver for AMD FP5 USB/DP Mux

BUG=b:138600585
BRANCH=none
TEST=build

Change-Id: I547309c7000e7d3ca8549a7e626a63789665305d
Signed-off-by: Edward Hill <ecgh@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1868921
Reviewed-by: Denis Brockus <dbrockus@chromium.org>

3 files changed, 119 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index 4af4264c22..b562d556a9 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -137,6 +137,7 @@ driver-$(CONFIG_USB_PD_RETIMER_INTEL_BB)+=retimer/bb_retimer.o
 driver-$(CONFIG_USBC_SS_MUX)+=usb_mux/usb_mux.o
 
 # USB muxes
+driver-$(CONFIG_USB_MUX_AMD_FP5)+=usb_mux/amd_fp5.o
 driver-$(CONFIG_USB_MUX_IT5205)+=usb_mux/it5205.o
 driver-$(CONFIG_USB_MUX_PI3USB30532)+=usb_mux/pi3usb30532.o
 driver-$(CONFIG_USB_MUX_PS8740)+=usb_mux/ps874x.o
diff --git a/driver/usb_mux/amd_fp5.c b/driver/usb_mux/amd_fp5.c
new file mode 100644
index 0000000000..f88df52577
--- /dev/null
+++ b/driver/usb_mux/amd_fp5.c
@@ -0,0 +1,97 @@
+/* Copyright 2019 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.
+ *
+ * AMD FP5 USB/DP Mux.
+ */
+
+#include "amd_fp5.h"
+#include "common.h"
+#include "i2c.h"
+#include "usb_mux.h"
+
+static inline int amd_fp5_mux_read(int port, uint8_t *val)
+{
+	uint8_t buf[3] = { 0 };
+	int rv;
+
+	rv = i2c_xfer(I2C_PORT_USB_MUX, AMD_FP5_MUX_I2C_ADDR_FLAGS,
+		      NULL, 0, buf, 3);
+	if (rv)
+		return rv;
+
+	*val = buf[port + 1];
+
+	return EC_SUCCESS;
+}
+
+static inline int amd_fp5_mux_write(int port, uint8_t val)
+{
+	return i2c_write8(I2C_PORT_USB_MUX, AMD_FP5_MUX_I2C_ADDR_FLAGS,
+			  port, val);
+}
+
+static int amd_fp5_init(int port)
+{
+	return EC_SUCCESS;
+}
+
+static int amd_fp5_set_mux(int port, mux_state_t mux_state)
+{
+	uint8_t val = 0;
+
+	if ((mux_state & MUX_USB_ENABLED) && (mux_state & MUX_DP_ENABLED))
+		val = (mux_state & MUX_POLARITY_INVERTED)
+			? AMD_FP5_MUX_DOCK_INVERTED : AMD_FP5_MUX_DOCK;
+	else if (mux_state & MUX_USB_ENABLED)
+		val = (mux_state & MUX_POLARITY_INVERTED)
+			? AMD_FP5_MUX_USB_INVERTED : AMD_FP5_MUX_USB;
+	else if (mux_state & MUX_DP_ENABLED)
+		val = (mux_state & MUX_POLARITY_INVERTED)
+			? AMD_FP5_MUX_DP_INVERTED : AMD_FP5_MUX_DP;
+
+	return amd_fp5_mux_write(port, val);
+}
+
+static int amd_fp5_get_mux(int port, mux_state_t *mux_state)
+{
+	uint8_t val = 0;
+	int rv;
+
+	rv = amd_fp5_mux_read(port, &val);
+	if (rv)
+		return rv;
+
+	switch (val) {
+	case AMD_FP5_MUX_USB:
+		*mux_state = MUX_USB_ENABLED;
+		break;
+	case AMD_FP5_MUX_USB_INVERTED:
+		*mux_state = MUX_USB_ENABLED | MUX_POLARITY_INVERTED;
+		break;
+	case AMD_FP5_MUX_DOCK:
+		*mux_state = MUX_USB_ENABLED | MUX_DP_ENABLED;
+		break;
+	case AMD_FP5_MUX_DOCK_INVERTED:
+		*mux_state = MUX_USB_ENABLED | MUX_DP_ENABLED
+			     | MUX_POLARITY_INVERTED;
+		break;
+	case AMD_FP5_MUX_DP:
+		*mux_state = MUX_DP_ENABLED;
+		break;
+	case AMD_FP5_MUX_DP_INVERTED:
+		*mux_state = MUX_DP_ENABLED | MUX_POLARITY_INVERTED;
+		break;
+	default:
+		*mux_state = 0;
+		break;
+	}
+
+	return EC_SUCCESS;
+}
+
+const struct usb_mux_driver amd_fp5_usb_mux_driver = {
+	.init = amd_fp5_init,
+	.set = amd_fp5_set_mux,
+	.get = amd_fp5_get_mux,
+};
diff --git a/driver/usb_mux/amd_fp5.h b/driver/usb_mux/amd_fp5.h
new file mode 100644
index 0000000000..7534ea0d8a
--- /dev/null
+++ b/driver/usb_mux/amd_fp5.h
@@ -0,0 +1,21 @@
+/* Copyright 2019 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.
+ *
+ * AMD FP5 USB/DP Mux.
+ */
+
+#ifndef __CROS_EC_USB_MUX_AMD_FP5_H
+#define __CROS_EC_USB_MUX_AMD_FP5_H
+
+#define AMD_FP5_MUX_I2C_ADDR_FLAGS	0x5C
+
+#define AMD_FP5_MUX_SAFE		0x00
+#define AMD_FP5_MUX_USB			0x02
+#define AMD_FP5_MUX_USB_INVERTED	0x11
+#define AMD_FP5_MUX_DOCK		0x06
+#define AMD_FP5_MUX_DOCK_INVERTED	0x19
+#define AMD_FP5_MUX_DP			0x0C
+#define AMD_FP5_MUX_DP_INVERTED		0x1C
+
+#endif /* __CROS_EC_USB_MUX_AMD_FP5_H */