Re: [PATCH v2 2/2] usb: typec: mux: Add support for the TUSB1046 crosspoint switch

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Thu, Oct 24, 2024 at 10:54:17AM +0200, Romain Gantois wrote:
> The TUSB1046-DCI is a USB-C linear redriver crosspoint switch, which can
> mux SuperSpeed lanes from a Type-C connector to a USB3.0 data lane or up to
> 4 display port lanes.
> 
> Add support for driving the TUSB1046 as a Type-C orientation switch and
> DisplayPort altmode multiplexer.
> 
> Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  MAINTAINERS                      |   7 ++
>  drivers/usb/typec/mux/Kconfig    |   9 ++
>  drivers/usb/typec/mux/Makefile   |   1 +
>  drivers/usb/typec/mux/tusb1046.c | 196 +++++++++++++++++++++++++++++++++++++++
>  4 files changed, 213 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index c27f3190737f8b85779bde5489639c8b899f4fd8..c880588b63f27d628edeec09fa7d904eeabbde92 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -24142,6 +24142,13 @@ L:	linux-usb@vger.kernel.org
>  S:	Orphan
>  F:	drivers/usb/typec/tcpm/
>  
> +USB TYPEC TUSB1046 MUX DRIVER
> +M:	Romain Gantois <romain.gantois@bootlin.com>
> +L:	linux-usb@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/usb/ti,tusb1046.yaml
> +F:	drivers/usb/typec/mux/tusb1046.c
> +
>  USB UHCI DRIVER
>  M:	Alan Stern <stern@rowland.harvard.edu>
>  L:	linux-usb@vger.kernel.org
> diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
> index ce7db6ad30572a0a74890f5f11944fb3ff07f635..67381b4ef4f68f4a6e73f157365ee24d0ab7109a 100644
> --- a/drivers/usb/typec/mux/Kconfig
> +++ b/drivers/usb/typec/mux/Kconfig
> @@ -66,6 +66,15 @@ config TYPEC_MUX_PTN36502
>  	  Say Y or M if your system has a NXP PTN36502 Type-C redriver chip
>  	  found on some devices with a Type-C port.
>  
> +config TYPEC_MUX_TUSB1046
> +	tristate "TI TUSB1046 Type-C crosspoint switch driver"
> +	depends on I2C
> +	help
> +	  Driver for the Texas Instruments TUSB1046-DCI crosspoint switch.
> +	  Supports flipping USB-C SuperSpeed lanes to adapt to orientation
> +	  changes, as well as muxing DisplayPort and sideband signals to a
> +	  common Type-C connector.
> +
>  config TYPEC_MUX_WCD939X_USBSS
>  	tristate "Qualcomm WCD939x USBSS Analog Audio Switch driver"
>  	depends on I2C
> diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
> index bb96f30267af05b33b9277dcf1cc0e1527d2dcdd..60879446da9365183567d3374a2fb7b5171fb3d7 100644
> --- a/drivers/usb/typec/mux/Makefile
> +++ b/drivers/usb/typec/mux/Makefile
> @@ -7,4 +7,5 @@ obj-$(CONFIG_TYPEC_MUX_INTEL_PMC)	+= intel_pmc_mux.o
>  obj-$(CONFIG_TYPEC_MUX_IT5205)		+= it5205.o
>  obj-$(CONFIG_TYPEC_MUX_NB7VPQ904M)	+= nb7vpq904m.o
>  obj-$(CONFIG_TYPEC_MUX_PTN36502)	+= ptn36502.o
> +obj-$(CONFIG_TYPEC_MUX_TUSB1046)	+= tusb1046.o
>  obj-$(CONFIG_TYPEC_MUX_WCD939X_USBSS)	+= wcd939x-usbss.o
> diff --git a/drivers/usb/typec/mux/tusb1046.c b/drivers/usb/typec/mux/tusb1046.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..b4f45c217b59fe033551e8e6379ad2d33ebedbcb
> --- /dev/null
> +++ b/drivers/usb/typec/mux/tusb1046.c
> @@ -0,0 +1,196 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for the TUSB1046-DCI USB Type-C crosspoint switch
> + *
> + * Copyright (C) 2024 Bootlin
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/i2c.h>
> +#include <linux/usb/typec_mux.h>
> +#include <linux/usb/typec_dp.h>
> +#include <linux/usb/typec_altmode.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/err.h>
> +#include <linux/of_device.h>
> +#include <linux/device.h>
> +#include <linux/mutex.h>
> +
> +#define TUSB1046_REG_GENERAL 0xa
> +
> +/* General register bits */
> +#define TUSB1046_GENERAL_FLIPSEL BIT(2)
> +#define TUSB1046_GENERAL_CTLSEL  GENMASK(1, 0)
> +
> +/* Mux modes */
> +#define TUSB1046_CTLSEL_DISABLED          0x0
> +#define TUSB1046_CTLSEL_USB3              0x1
> +#define TUSB1046_CTLSEL_4LANE_DP          0x2
> +#define TUSB1046_CTLSEL_USB3_AND_2LANE_DP 0x3
> +
> +struct tusb1046_priv {
> +	struct i2c_client *client;
> +	struct typec_switch_dev *sw;
> +	struct typec_mux_dev *mux;
> +
> +	/* Lock General register during accesses */
> +	struct mutex general_reg_lock;
> +};
> +
> +static int tusb1046_mux_set(struct typec_mux_dev *mux,
> +			    struct typec_mux_state *state)
> +{
> +	struct tusb1046_priv *priv = typec_mux_get_drvdata(mux);
> +	struct i2c_client *client = priv->client;
> +	struct device *dev = &client->dev;
> +	int mode, val, ret = 0;
> +
> +	if (state->mode >= TYPEC_STATE_MODAL &&
> +	    state->alt->svid != USB_TYPEC_DP_SID)
> +		return -EINVAL;
> +
> +	dev_dbg(dev, "mux mode requested: %lu\n", state->mode);
> +
> +	mutex_lock(&priv->general_reg_lock);
> +
> +	val = i2c_smbus_read_byte_data(client, TUSB1046_REG_GENERAL);
> +	if (val < 0) {
> +		dev_err(dev, "failed to read ctlsel status, err %d\n", val);
> +		ret = val;
> +		goto out_unlock;
> +	}
> +
> +	switch (state->mode) {
> +	case TYPEC_STATE_USB:
> +		mode = TUSB1046_CTLSEL_USB3;
> +		break;
> +	case TYPEC_DP_STATE_C:
> +	case TYPEC_DP_STATE_E:
> +		mode = TUSB1046_CTLSEL_4LANE_DP;
> +		break;
> +	case TYPEC_DP_STATE_D:
> +		mode = TUSB1046_CTLSEL_USB3_AND_2LANE_DP;
> +		break;
> +	case TYPEC_STATE_SAFE:
> +	default:
> +		mode = TUSB1046_CTLSEL_DISABLED;
> +		break;
> +	}
> +
> +	val &= ~TUSB1046_GENERAL_CTLSEL;
> +	val |= mode;
> +
> +	ret = i2c_smbus_write_byte_data(client, TUSB1046_REG_GENERAL, val);
> +
> +out_unlock:
> +	mutex_unlock(&priv->general_reg_lock);
> +	return ret;
> +}
> +
> +static int tusb1046_switch_set(struct typec_switch_dev *sw,
> +			       enum typec_orientation orientation)
> +{
> +	struct tusb1046_priv *priv = typec_switch_get_drvdata(sw);
> +	struct i2c_client *client = priv->client;
> +	struct device *dev = &client->dev;
> +	int val, ret = 0;
> +
> +	dev_dbg(dev, "setting USB3.0 lane flip for orientation %d\n", orientation);
> +
> +	mutex_lock(&priv->general_reg_lock);
> +
> +	val = i2c_smbus_read_byte_data(client, TUSB1046_REG_GENERAL);
> +	if (val < 0) {
> +		dev_err(dev, "failed to read flipsel status, err %d\n", val);
> +		ret = val;
> +		goto out_unlock;
> +	}
> +
> +	if (orientation == TYPEC_ORIENTATION_REVERSE)
> +		val |= TUSB1046_GENERAL_FLIPSEL;
> +	else
> +		val &= ~TUSB1046_GENERAL_FLIPSEL;
> +
> +	ret = i2c_smbus_write_byte_data(client, TUSB1046_REG_GENERAL, val);
> +
> +out_unlock:
> +	mutex_unlock(&priv->general_reg_lock);
> +	return ret;
> +}
> +
> +static int tusb1046_i2c_probe(struct i2c_client *client)
> +{
> +	struct typec_switch_desc sw_desc = { };
> +	struct typec_mux_desc mux_desc = { };
> +	struct device *dev = &client->dev;
> +	struct tusb1046_priv *priv;
> +	int ret = 0;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return dev_err_probe(dev, -ENOMEM, "failed to allocate driver data\n");
> +
> +	priv->client = client;
> +
> +	mutex_init(&priv->general_reg_lock);
> +
> +	sw_desc.drvdata = priv;
> +	sw_desc.fwnode = dev_fwnode(dev);
> +	sw_desc.set = tusb1046_switch_set;
> +
> +	priv->sw = typec_switch_register(dev, &sw_desc);
> +	if (IS_ERR(priv->sw)) {
> +		ret = dev_err_probe(dev, PTR_ERR(priv->sw), "failed to register type-c switch\n");
> +		goto err_destroy_mutex;
> +	}
> +
> +	mux_desc.drvdata = priv;
> +	mux_desc.fwnode = dev_fwnode(dev);
> +	mux_desc.set = tusb1046_mux_set;
> +
> +	priv->mux = typec_mux_register(dev, &mux_desc);
> +	if (IS_ERR(priv->mux)) {
> +		ret = dev_err_probe(dev, PTR_ERR(priv->mux), "failed to register type-c mux\n");
> +		goto err_unregister_switch;
> +	}
> +
> +	i2c_set_clientdata(client, priv);
> +
> +	return 0;
> +
> +err_unregister_switch:
> +	typec_switch_unregister(priv->sw);
> +err_destroy_mutex:
> +	mutex_destroy(&priv->general_reg_lock);
> +	return ret;
> +}
> +
> +static void tusb1046_i2c_remove(struct i2c_client *client)
> +{
> +	struct tusb1046_priv *priv = i2c_get_clientdata(client);
> +
> +	typec_switch_unregister(priv->sw);
> +	typec_mux_unregister(priv->mux);
> +	mutex_destroy(&priv->general_reg_lock);
> +}
> +
> +static const struct of_device_id tusb1046_match_table[] = {
> +	{.compatible = "ti,tusb1046"},
> +	{},
> +};
> +
> +static struct i2c_driver tusb1046_driver = {
> +	.driver = {
> +		.name = "tusb1046",
> +		.of_match_table = tusb1046_match_table,
> +	},
> +	.probe = tusb1046_i2c_probe,
> +	.remove = tusb1046_i2c_remove,
> +};
> +
> +module_i2c_driver(tusb1046_driver);
> +
> +MODULE_DESCRIPTION("TUSB1046 USB Type-C switch driver");
> +MODULE_AUTHOR("Romain Gantois <romain.gantois@bootlin.com>");
> +MODULE_LICENSE("GPL");
> 
> -- 
> 2.47.0

-- 
heikki