On Fri, Apr 22, 2022 at 03:23:51PM -0700, Bjorn Andersson wrote:
> The ON Semiconductor FSA4480 is a USB Type-C port multimedia switch with
> support for analog audio headsets. It allows sharing a common USB Type-C
> port to pass USB2.0 signal, analog audio, sideband use wires and analog
> microphone signal.
>
> Due to lacking upstream audio support for testing, the audio muxing is
> left untouched, but implementation of muxing the SBU lines is provided
> as a pair of Type-C mux and switch devices. This provides the necessary
> support for enabling the DisplayPort altmode on devices with this
> circuit.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
>
> Changes since v4:
> - Disable locking of the regmap
> - Use dev_fwnode() instead of explicit dereference
>
> drivers/usb/typec/mux/Kconfig | 10 ++
> drivers/usb/typec/mux/Makefile | 1 +
> drivers/usb/typec/mux/fsa4480.c | 218 ++++++++++++++++++++++++++++++++
> 3 files changed, 229 insertions(+)
> create mode 100644 drivers/usb/typec/mux/fsa4480.c
>
> diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
> index edead555835e..5eb2c17d72c1 100644
> --- a/drivers/usb/typec/mux/Kconfig
> +++ b/drivers/usb/typec/mux/Kconfig
> @@ -2,6 +2,16 @@
>
> menu "USB Type-C Multiplexer/DeMultiplexer Switch support"
>
> +config TYPEC_MUX_FSA4480
> + tristate "ON Semi FSA4480 Analog Audio Switch driver"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + Driver for the ON Semiconductor FSA4480 Analog Audio Switch, which
> + provides support for muxing analog audio and sideband signals on a
> + common USB Type-C connector.
> + If compiled as a module, the module will be named fsa4480.
> +
> config TYPEC_MUX_PI3USB30532
> tristate "Pericom PI3USB30532 Type-C cross switch driver"
> depends on I2C
> diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
> index 280a6f553115..e52a56c16bfb 100644
> --- a/drivers/usb/typec/mux/Makefile
> +++ b/drivers/usb/typec/mux/Makefile
> @@ -1,4 +1,5 @@
> # SPDX-License-Identifier: GPL-2.0
>
> +obj-$(CONFIG_TYPEC_MUX_FSA4480) += fsa4480.o
> obj-$(CONFIG_TYPEC_MUX_PI3USB30532) += pi3usb30532.o
> obj-$(CONFIG_TYPEC_MUX_INTEL_PMC) += intel_pmc_mux.o
> diff --git a/drivers/usb/typec/mux/fsa4480.c b/drivers/usb/typec/mux/fsa4480.c
> new file mode 100644
> index 000000000000..6184f5367190
> --- /dev/null
> +++ b/drivers/usb/typec/mux/fsa4480.c
> @@ -0,0 +1,218 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021-2022 Linaro Ltd.
> + * Copyright (C) 2018-2020 The Linux Foundation
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/regmap.h>
> +#include <linux/usb/typec_dp.h>
> +#include <linux/usb/typec_mux.h>
> +
> +#define FSA4480_SWITCH_ENABLE 0x04
> +#define FSA4480_SWITCH_SELECT 0x05
> +#define FSA4480_SWITCH_STATUS1 0x07
> +#define FSA4480_SLOW_L 0x08
> +#define FSA4480_SLOW_R 0x09
> +#define FSA4480_SLOW_MIC 0x0a
> +#define FSA4480_SLOW_SENSE 0x0b
> +#define FSA4480_SLOW_GND 0x0c
> +#define FSA4480_DELAY_L_R 0x0d
> +#define FSA4480_DELAY_L_MIC 0x0e
> +#define FSA4480_DELAY_L_SENSE 0x0f
> +#define FSA4480_DELAY_L_AGND 0x10
> +#define FSA4480_RESET 0x1e
> +#define FSA4480_MAX_REGISTER 0x1f
> +
> +#define FSA4480_ENABLE_DEVICE BIT(7)
> +#define FSA4480_ENABLE_SBU GENMASK(6, 5)
> +#define FSA4480_ENABLE_USB GENMASK(4, 3)
> +
> +#define FSA4480_SEL_SBU_REVERSE GENMASK(6, 5)
> +#define FSA4480_SEL_USB GENMASK(4, 3)
> +
> +struct fsa4480 {
> + struct i2c_client *client;
> +
> + /* used to serialize concurrent change requests */
> + struct mutex lock;
> +
> + struct typec_switch_dev *sw;
> + struct typec_mux_dev *mux;
> +
> + struct regmap *regmap;
> +
> + u8 cur_enable;
> + u8 cur_select;
> +};
> +
> +static const struct regmap_config fsa4480_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = FSA4480_MAX_REGISTER,
> + /* Accesses only done under fsa4480->lock */
> + .disable_locking = true,
> +};
> +
> +static int fsa4480_switch_set(struct typec_switch_dev *sw,
> + enum typec_orientation orientation)
> +{
> + struct fsa4480 *fsa = typec_switch_get_drvdata(sw);
> + u8 new_sel;
> +
> + mutex_lock(&fsa->lock);
> + new_sel = FSA4480_SEL_USB;
> + if (orientation == TYPEC_ORIENTATION_REVERSE)
> + new_sel |= FSA4480_SEL_SBU_REVERSE;
> +
> + if (new_sel == fsa->cur_select)
> + goto out_unlock;
> +
> + if (fsa->cur_enable & FSA4480_ENABLE_SBU) {
> + /* Disable SBU output while re-configuring the switch */
> + regmap_write(fsa->regmap, FSA4480_SWITCH_ENABLE,
> + fsa->cur_enable & ~FSA4480_ENABLE_SBU);
> +
> + /* 35us to allow the SBU switch to turn off */
> + usleep_range(35, 1000);
> + }
> +
> + regmap_write(fsa->regmap, FSA4480_SWITCH_SELECT, new_sel);
> + fsa->cur_select = new_sel;
> +
> + if (fsa->cur_enable & FSA4480_ENABLE_SBU) {
> + regmap_write(fsa->regmap, FSA4480_SWITCH_ENABLE, fsa->cur_enable);
> +
> + /* 15us to allow the SBU switch to turn on again */
> + usleep_range(15, 1000);
> + }
> +
> +out_unlock:
> + mutex_unlock(&fsa->lock);
> +
> + return 0;
> +}
> +
> +static int fsa4480_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state)
> +{
> + struct fsa4480 *fsa = typec_mux_get_drvdata(mux);
> + u8 new_enable;
> +
> + mutex_lock(&fsa->lock);
> +
> + new_enable = FSA4480_ENABLE_DEVICE | FSA4480_ENABLE_USB;
> + if (state->mode >= TYPEC_DP_STATE_A)
> + new_enable |= FSA4480_ENABLE_SBU;
> +
> + if (new_enable == fsa->cur_enable)
> + goto out_unlock;
> +
> + regmap_write(fsa->regmap, FSA4480_SWITCH_ENABLE, new_enable);
> + fsa->cur_enable = new_enable;
> +
> + if (new_enable & FSA4480_ENABLE_SBU) {
> + /* 15us to allow the SBU switch to turn off */
> + usleep_range(15, 1000);
> + }
> +
> +out_unlock:
> + mutex_unlock(&fsa->lock);
> +
> + return 0;
> +}
> +
> +static int fsa4480_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct typec_switch_desc sw_desc = { };
> + struct typec_mux_desc mux_desc = { };
> + struct fsa4480 *fsa;
> +
> + fsa = devm_kzalloc(dev, sizeof(*fsa), GFP_KERNEL);
> + if (!fsa)
> + return -ENOMEM;
> +
> + fsa->client = client;
> + mutex_init(&fsa->lock);
> +
> + fsa->regmap = devm_regmap_init_i2c(client, &fsa4480_regmap_config);
> + if (IS_ERR(fsa->regmap))
> + return dev_err_probe(dev, PTR_ERR(fsa->regmap), "failed to initialize regmap\n");
> +
> + fsa->cur_enable = FSA4480_ENABLE_DEVICE | FSA4480_ENABLE_USB;
> + fsa->cur_select = FSA4480_SEL_USB;
> +
> + /* set default settings */
> + regmap_write(fsa->regmap, FSA4480_SLOW_L, 0x00);
> + regmap_write(fsa->regmap, FSA4480_SLOW_R, 0x00);
> + regmap_write(fsa->regmap, FSA4480_SLOW_MIC, 0x00);
> + regmap_write(fsa->regmap, FSA4480_SLOW_SENSE, 0x00);
> + regmap_write(fsa->regmap, FSA4480_SLOW_GND, 0x00);
> + regmap_write(fsa->regmap, FSA4480_DELAY_L_R, 0x00);
> + regmap_write(fsa->regmap, FSA4480_DELAY_L_MIC, 0x00);
> + regmap_write(fsa->regmap, FSA4480_DELAY_L_SENSE, 0x00);
> + regmap_write(fsa->regmap, FSA4480_DELAY_L_AGND, 0x09);
> + regmap_write(fsa->regmap, FSA4480_SWITCH_SELECT, fsa->cur_select);
> + regmap_write(fsa->regmap, FSA4480_SWITCH_ENABLE, fsa->cur_enable);
> +
> + sw_desc.drvdata = fsa;
> + sw_desc.fwnode = dev_fwnode(dev);
> + sw_desc.set = fsa4480_switch_set;
> +
> + fsa->sw = typec_switch_register(dev, &sw_desc);
> + if (IS_ERR(fsa->sw))
> + return dev_err_probe(dev, PTR_ERR(fsa->sw), "failed to register typec switch\n");
> +
> + mux_desc.drvdata = fsa;
> + mux_desc.fwnode = dev_fwnode(dev);
> + mux_desc.set = fsa4480_mux_set;
> +
> + fsa->mux = typec_mux_register(dev, &mux_desc);
> + if (IS_ERR(fsa->mux)) {
> + typec_switch_unregister(fsa->sw);
> + return dev_err_probe(dev, PTR_ERR(fsa->mux), "failed to register typec mux\n");
> + }
> +
> + i2c_set_clientdata(client, fsa);
> + return 0;
> +}
> +
> +static int fsa4480_remove(struct i2c_client *client)
> +{
> + struct fsa4480 *fsa = i2c_get_clientdata(client);
> +
> + typec_mux_unregister(fsa->mux);
> + typec_switch_unregister(fsa->sw);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id fsa4480_table[] = {
> + { "fsa4480" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, fsa4480_table);
> +
> +static const struct of_device_id fsa4480_of_table[] = {
> + { .compatible = "fcs,fsa4480" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, fsa4480_of_table);
> +
> +static struct i2c_driver fsa4480_driver = {
> + .driver = {
> + .name = "fsa4480",
> + .of_match_table = fsa4480_of_table,
> + },
> + .probe_new = fsa4480_probe,
> + .remove = fsa4480_remove,
> + .id_table = fsa4480_table,
> +};
> +module_i2c_driver(fsa4480_driver);
> +
> +MODULE_DESCRIPTION("ON Semiconductor FSA4480 driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.35.1
--
heikki
