TUSB544: Add driver

Driver code for the TUSB544 redriver

BRANCH=None
BUG=b:149561847
TEST=builds

Change-Id: I391d6d264ff9d326c2d45569124dd1366f892812
Signed-off-by: Diana Z <dzigterman@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2062766
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

2 files changed, 142 insertions, 0 deletions

diff --git a/driver/retimer/tusb544.c b/driver/retimer/tusb544.c
new file mode 100644
index 0000000000..3d8cb9119e
--- /dev/null
+++ b/driver/retimer/tusb544.c
@@ -0,0 +1,93 @@
+/* Copyright 2020 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.
+ *
+ * TI TUSB544 USB Type-C Multi-Protocol Linear Redriver
+ */
+#include "i2c.h"
+#include "tusb544.h"
+#include "usb_mux.h"
+
+static int tusb544_write(int port, int offset, int data)
+{
+	return i2c_write8(usb_retimers[port].i2c_port,
+			  usb_retimers[port].i2c_addr_flags,
+			  offset, data);
+}
+
+static int tusb544_read(int port, int offset, int *data)
+{
+	return i2c_read8(usb_retimers[port].i2c_port,
+			  usb_retimers[port].i2c_addr_flags,
+			  offset, data);
+}
+
+static int tusb544_enter_low_power_mode(int port)
+{
+	int reg;
+	int rv;
+
+	rv = tusb544_read(port, TUSB544_REG_GENERAL4, &reg);
+	if (rv)
+		return rv;
+
+	/* Setting CTL_SEL[0,1] to 0 powers down, per Table 5 */
+	reg &= ~TUSB544_GEN4_CTL_SEL;
+
+	return tusb544_write(port, TUSB544_REG_GENERAL4, reg);
+}
+
+static int tusb544_init(int port)
+{
+	return EC_SUCCESS;
+}
+
+static int tusb544_set_mux(int port, mux_state_t mux_state)
+{
+	int reg;
+	int rv;
+
+	if (mux_state == USB_PD_MUX_NONE)
+		return tusb544_enter_low_power_mode(port);
+
+	rv = tusb544_read(port, TUSB544_REG_GENERAL4, &reg);
+	if (rv)
+		return rv;
+
+	if (mux_state & USB_PD_MUX_POLARITY_INVERTED)
+		reg |= TUSB544_GEN4_FLIP_SEL;
+	else
+		reg &= ~TUSB544_GEN4_FLIP_SEL;
+
+	reg &= ~TUSB544_GEN4_CTL_SEL;
+
+	if ((mux_state & USB_PD_MUX_USB_ENABLED) &&
+	    (mux_state & USB_PD_MUX_DP_ENABLED))
+		reg |= TUSB544_CTL_SEL_DP_USB;
+	else if (mux_state & USB_PD_MUX_DP_ENABLED)
+		reg |= TUSB544_CTL_SEL_DP_ONLY;
+	else if (mux_state & USB_PD_MUX_USB_ENABLED)
+		reg |= TUSB544_CTL_SEL_USB_ONLY;
+
+	rv = tusb544_write(port, TUSB544_REG_GENERAL4, reg);
+	if (rv)
+		return rv;
+
+	rv = tusb544_read(port, TUSB544_REG_GENERAL6, &reg);
+	if (rv)
+		return rv;
+
+	reg &= ~TUSB544_GEN6_DIR_SEL;
+	if (pd_get_power_role(port) == PD_ROLE_SOURCE)
+		reg |= TUSB544_DIR_SEL_USB_DP_SRC;
+	else
+		reg |= TUSB544_DIR_SEL_USB_DP_SNK;
+
+	return tusb544_write(port, TUSB544_REG_GENERAL6, reg);
+}
+
+const struct usb_retimer_driver tusb544_usb_redriver_drv = {
+	.enter_low_power_mode = &tusb544_enter_low_power_mode,
+	.init = &tusb544_init,
+	.set = &tusb544_set_mux,
+};
diff --git a/driver/retimer/tusb544.h b/driver/retimer/tusb544.h
new file mode 100644
index 0000000000..7a1b0a82cd
--- /dev/null
+++ b/driver/retimer/tusb544.h
@@ -0,0 +1,49 @@
+/* Copyright 2020 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.
+ *
+ * TI TUSB544 USB Type-C Multi-Protocol Linear Redriver
+ */
+
+#ifndef __CROS_EC_USB_REDRIVER_TUSB544_H
+#define __CROS_EC_USB_REDRIVER_TUSB544_H
+
+#define TUSB544_ADDR_FLAGS0 0x44
+
+#define TUSB544_REG_GENERAL4	0x0A
+#define TUSB544_GEN4_CTL_SEL	GENMASK(1, 0)
+#define TUSB544_GEN4_FLIP_SEL	BIT(2)
+#define TUSB544_GEN4_HPDIN	BIT(3)
+#define TUSB544_GEN4_EQ_OVRD	BIT(4)
+#define TUSB544_GEN4_SWAP_SEL	BIT(5)
+
+enum tusb544_ct_sel {
+	TUSB544_CTL_SEL_DISABLED,
+	TUSB544_CTL_SEL_USB_ONLY,
+	TUSB544_CTL_SEL_DP_ONLY,
+	TUSB544_CTL_SEL_DP_USB,
+};
+
+#define TUSB544_REG_GENERAL6	0x0C
+#define TUSB544_GEN6_DIR_SEL	GENMASK(1, 0)
+
+enum tusb544_dir_sel {
+	TUSB544_DIR_SEL_USB_DP_SRC,
+	TUSB544_DIR_SEL_USB_DP_SNK,
+	TUSB544_DIR_SEL_CUSTOM_SRC,
+	TUSB544_DIS_SEL_CUSTOM_SNK,
+};
+
+/*
+ * Note: TUSB544 automatically snoops DP lanes to enable, but may be manually
+ * directed which lanes to turn on when snoop is disabled
+ */
+#define TUSB544_REG_DP4			0x13
+#define TUSB544_DP4_DP0_DISABLE		BIT(0)
+#define TUSB544_DP4_DP1_DISABLE		BIT(1)
+#define TUSB544_DP4_DP2_DISABLE		BIT(2)
+#define TUSB544_DP4_DP3_DISABLE		BIT(3)
+#define TUSB544_DP4_AUX_SBU_OVR		GENMASK(5, 4)
+#define TUSB544_DP4_AUX_SNOOP_DISABLE	BIT(7)
+
+#endif