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Date: Wed, 24 Jan 2024 15:43:14 +0200
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: gregkh@linuxfoundation.org, robh+dt@kernel.org,
	krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
	matthias.bgg@gmail.com, dmitry.baryshkov@linaro.org,
	neil.armstrong@linaro.org, andersson@kernel.org, nathan@kernel.org,
	luca.weiss@fairphone.com, tianping.fang@mediatek.com,
	linux-usb@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, kernel@collabora.com
Subject: Re: [PATCH v3 2/2] usb: typec: mux: Add ITE IT5205 Alternate Mode
 Passive MUX driver
Message-ID: <ZbET8jEdp0wYgJq1@kuha.fi.intel.com>
References: <20240122110446.140226-1-angelogioacchino.delregno@collabora.com>
 <20240122110446.140226-3-angelogioacchino.delregno@collabora.com>
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In-Reply-To: <20240122110446.140226-3-angelogioacchino.delregno@collabora.com>

On Mon, Jan 22, 2024 at 12:04:46PM +0100, AngeloGioacchino Del Regno wrote:
> The ITE IT5202 is a USB Type-C Alternate Mode Passive MUX, used for
> muxing the SBU lines of a Type-C port with DisplayPort altmode and
> also providing an orientation switch.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

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

> ---
>  drivers/usb/typec/mux/Kconfig  |  10 ++
>  drivers/usb/typec/mux/Makefile |   1 +
>  drivers/usb/typec/mux/it5205.c | 294 +++++++++++++++++++++++++++++++++
>  3 files changed, 305 insertions(+)
>  create mode 100644 drivers/usb/typec/mux/it5205.c
> 
> diff --git a/drivers/usb/typec/mux/Kconfig b/drivers/usb/typec/mux/Kconfig
> index d2cb5e733e57..399c7b0983df 100644
> --- a/drivers/usb/typec/mux/Kconfig
> +++ b/drivers/usb/typec/mux/Kconfig
> @@ -36,6 +36,16 @@ config TYPEC_MUX_INTEL_PMC
>  	  control the USB role switch and also the multiplexer/demultiplexer
>  	  switches used with USB Type-C Alternate Modes.
>  
> +config TYPEC_MUX_IT5205
> +	tristate "ITE IT5205 Type-C USB Alt Mode Passive MUX driver"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  Driver for the ITE IT5205 Type-C USB Alternate Mode Passive MUX
> +	  which provides support for muxing DisplayPort and sideband signals
> +	  on a common USB Type-C connector.
> +	  If compiled as a module, the module will be named it5205.
> +
>  config TYPEC_MUX_NB7VPQ904M
>  	tristate "On Semiconductor NB7VPQ904M Type-C redriver driver"
>  	depends on I2C
> diff --git a/drivers/usb/typec/mux/Makefile b/drivers/usb/typec/mux/Makefile
> index 57dc9ac6f8dc..bb96f30267af 100644
> --- a/drivers/usb/typec/mux/Makefile
> +++ b/drivers/usb/typec/mux/Makefile
> @@ -4,6 +4,7 @@ obj-$(CONFIG_TYPEC_MUX_FSA4480)		+= fsa4480.o
>  obj-$(CONFIG_TYPEC_MUX_GPIO_SBU)	+= gpio-sbu-mux.o
>  obj-$(CONFIG_TYPEC_MUX_PI3USB30532)	+= pi3usb30532.o
>  obj-$(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_WCD939X_USBSS)	+= wcd939x-usbss.o
> diff --git a/drivers/usb/typec/mux/it5205.c b/drivers/usb/typec/mux/it5205.c
> new file mode 100644
> index 000000000000..5535932e42cd
> --- /dev/null
> +++ b/drivers/usb/typec/mux/it5205.c
> @@ -0,0 +1,294 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ITE IT5205 Type-C USB alternate mode passive mux
> + *
> + * Copyright (c) 2020 MediaTek Inc.
> + * Copyright (c) 2024 Collabora Ltd.
> + *                    AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> + *
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/usb/tcpm.h>
> +#include <linux/usb/typec.h>
> +#include <linux/usb/typec_dp.h>
> +#include <linux/usb/typec_mux.h>
> +
> +#define IT5205_REG_CHIP_ID(x)	(0x4 + (x))
> +#define IT5205FN_CHIP_ID	0x35323035 /* "5205" */
> +
> +/* MUX power down register */
> +#define IT5205_REG_MUXPDR        0x10
> +#define IT5205_MUX_POWER_DOWN    BIT(0)
> +
> +/* MUX control register */
> +#define IT5205_REG_MUXCR         0x11
> +#define IT5205_POLARITY_INVERTED BIT(4)
> +#define IT5205_DP_USB_CTRL_MASK  GENMASK(3, 0)
> +#define IT5205_DP                0x0f
> +#define IT5205_DP_USB            0x03
> +#define IT5205_USB               0x07
> +
> +/* Vref Select Register */
> +#define IT5205_REG_VSR            0x10
> +#define IT5205_VREF_SELECT_MASK   GENMASK(5, 4)
> +#define IT5205_VREF_SELECT_3_3V   0x00
> +#define IT5205_VREF_SELECT_OFF    0x20
> +
> +/* CSBU Over Voltage Protection Register */
> +#define IT5205_REG_CSBUOVPSR      0x1e
> +#define IT5205_OVP_SELECT_MASK    GENMASK(5, 4)
> +#define IT5205_OVP_3_90V          0x00
> +#define IT5205_OVP_3_68V          0x10
> +#define IT5205_OVP_3_62V          0x20
> +#define IT5205_OVP_3_57V          0x30
> +
> +/* CSBU Switch Register */
> +#define IT5205_REG_CSBUSR         0x22
> +#define IT5205_CSBUSR_SWITCH      BIT(0)
> +
> +/* Interrupt Switch Register */
> +#define IT5205_REG_ISR            0x25
> +#define IT5205_ISR_CSBU_MASK      BIT(4)
> +#define IT5205_ISR_CSBU_OVP       BIT(0)
> +
> +struct it5205 {
> +	struct i2c_client *client;
> +	struct regmap *regmap;
> +	struct typec_switch_dev *sw;
> +	struct typec_mux_dev *mux;
> +};
> +
> +static int it5205_switch_set(struct typec_switch_dev *sw, enum typec_orientation orientation)
> +{
> +	struct it5205 *it = typec_switch_get_drvdata(sw);
> +
> +	switch (orientation) {
> +	case TYPEC_ORIENTATION_NORMAL:
> +		regmap_update_bits(it->regmap, IT5205_REG_MUXCR,
> +				   IT5205_POLARITY_INVERTED, 0);
> +		break;
> +	case TYPEC_ORIENTATION_REVERSE:
> +		regmap_update_bits(it->regmap, IT5205_REG_MUXCR,
> +				   IT5205_POLARITY_INVERTED, IT5205_POLARITY_INVERTED);
> +		break;
> +	case TYPEC_ORIENTATION_NONE:
> +		fallthrough;
> +	default:
> +		regmap_write(it->regmap, IT5205_REG_MUXCR, 0);
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int it5205_mux_set(struct typec_mux_dev *mux, struct typec_mux_state *state)
> +{
> +	struct it5205 *it = typec_mux_get_drvdata(mux);
> +	u8 val;
> +
> +	if (state->mode >= TYPEC_STATE_MODAL &&
> +	    state->alt->svid != USB_TYPEC_DP_SID)
> +		return -EINVAL;
> +
> +	switch (state->mode) {
> +	case TYPEC_STATE_USB:
> +		val = IT5205_USB;
> +		break;
> +	case TYPEC_DP_STATE_C:
> +		fallthrough;
> +	case TYPEC_DP_STATE_E:
> +		val = IT5205_DP;
> +		break;
> +	case TYPEC_DP_STATE_D:
> +		val = IT5205_DP_USB;
> +		break;
> +	case TYPEC_STATE_SAFE:
> +		fallthrough;
> +	default:
> +		val = 0;
> +		break;
> +	}
> +
> +	return regmap_update_bits(it->regmap, IT5205_REG_MUXCR,
> +				  IT5205_DP_USB_CTRL_MASK, val);
> +}
> +
> +static irqreturn_t it5205_irq_handler(int irq, void *data)
> +{
> +	struct it5205 *it = data;
> +	int ret;
> +	u32 val;
> +
> +	ret = regmap_read(it->regmap, IT5205_REG_ISR, &val);
> +	if (ret)
> +		return IRQ_NONE;
> +
> +	if (val & IT5205_ISR_CSBU_OVP) {
> +		dev_warn(&it->client->dev, "Overvoltage detected!\n");
> +
> +		/* Reset CSBU */
> +		regmap_update_bits(it->regmap, IT5205_REG_CSBUSR,
> +				   IT5205_CSBUSR_SWITCH, 0);
> +		regmap_update_bits(it->regmap, IT5205_REG_CSBUSR,
> +				   IT5205_CSBUSR_SWITCH, IT5205_CSBUSR_SWITCH);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void it5205_enable_ovp(struct it5205 *it)
> +{
> +	/* Select Vref 3.3v */
> +	regmap_update_bits(it->regmap, IT5205_REG_VSR,
> +			   IT5205_VREF_SELECT_MASK, IT5205_VREF_SELECT_3_3V);
> +
> +	/* Trigger OVP at 3.68V */
> +	regmap_update_bits(it->regmap, IT5205_REG_CSBUOVPSR,
> +			   IT5205_OVP_SELECT_MASK, IT5205_OVP_3_68V);
> +
> +	/* Unmask OVP interrupt */
> +	regmap_update_bits(it->regmap, IT5205_REG_ISR,
> +			   IT5205_ISR_CSBU_MASK, 0);
> +
> +	/* Enable CSBU Interrupt */
> +	regmap_update_bits(it->regmap, IT5205_REG_CSBUSR,
> +			   IT5205_CSBUSR_SWITCH, IT5205_CSBUSR_SWITCH);
> +}
> +
> +static const struct regmap_config it5205_regmap = {
> +	.max_register = 0x2f,
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +};
> +
> +static int it5205_probe(struct i2c_client *client)
> +{
> +	struct typec_switch_desc sw_desc = { };
> +	struct typec_mux_desc mux_desc = { };
> +	struct device *dev = &client->dev;
> +	struct it5205 *it;
> +	u32 val, chipid = 0;
> +	int i, ret;
> +
> +	it = devm_kzalloc(dev, sizeof(*it), GFP_KERNEL);
> +	if (!it)
> +		return -ENOMEM;
> +
> +	ret = devm_regulator_get_enable(dev, "vcc");
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get regulator\n");
> +
> +	it->client = client;
> +
> +	it->regmap = devm_regmap_init_i2c(client, &it5205_regmap);
> +	if (IS_ERR(it->regmap))
> +		return dev_err_probe(dev, PTR_ERR(it->regmap),
> +				     "Failed to init regmap\n");
> +
> +	/* IT5205 needs a long time to power up after enabling regulator */
> +	msleep(50);
> +
> +	/* Unset poweroff bit */
> +	ret = regmap_write(it->regmap, IT5205_REG_MUXPDR, 0);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to set power on\n");
> +
> +	/* Read the 32 bits ChipID */
> +	for (i = 3; i >= 0; i--) {
> +		ret = regmap_read(it->regmap, IT5205_REG_CHIP_ID(i), &val);
> +		if (ret)
> +			return ret;
> +
> +		chipid |= val << (i * 8);
> +	}
> +
> +	if (chipid != IT5205FN_CHIP_ID)
> +		return dev_err_probe(dev, -EINVAL,
> +				     "Unknown ChipID 0x%x\n", chipid);
> +
> +	/* Initialize as USB mode with default (non-inverted) polarity */
> +	ret = regmap_write(it->regmap, IT5205_REG_MUXCR, IT5205_USB);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Cannot set mode to USB\n");
> +
> +	sw_desc.drvdata = it;
> +	sw_desc.fwnode = dev_fwnode(dev);
> +	sw_desc.set = it5205_switch_set;
> +
> +	it->sw = typec_switch_register(dev, &sw_desc);
> +	if (IS_ERR(it->sw))
> +		return dev_err_probe(dev, PTR_ERR(it->sw),
> +				     "failed to register typec switch\n");
> +
> +	mux_desc.drvdata = it;
> +	mux_desc.fwnode = dev_fwnode(dev);
> +	mux_desc.set = it5205_mux_set;
> +
> +	it->mux = typec_mux_register(dev, &mux_desc);
> +	if (IS_ERR(it->mux)) {
> +		typec_switch_unregister(it->sw);
> +		return dev_err_probe(dev, PTR_ERR(it->mux),
> +				     "failed to register typec mux\n");
> +	}
> +
> +	i2c_set_clientdata(client, it);
> +
> +	if (of_property_read_bool(dev->of_node, "ite,ovp-enable") && client->irq) {
> +		it5205_enable_ovp(it);
> +
> +		ret = devm_request_threaded_irq(dev, client->irq, NULL,
> +						it5205_irq_handler,
> +						IRQF_ONESHOT, dev_name(dev), it);
> +		if (ret) {
> +			typec_mux_unregister(it->mux);
> +			typec_switch_unregister(it->sw);
> +			return dev_err_probe(dev, ret, "Failed to request irq\n");
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static void it5205_remove(struct i2c_client *client)
> +{
> +	struct it5205 *it = i2c_get_clientdata(client);
> +
> +	typec_mux_unregister(it->mux);
> +	typec_switch_unregister(it->sw);
> +}
> +
> +static const struct i2c_device_id it5205_table[] = {
> +	{ "it5205" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, it5205_table);
> +
> +static const struct of_device_id it5205_of_table[] = {
> +	{ .compatible = "ite,it5205" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, it5205_of_table);
> +
> +static struct i2c_driver it5205_driver = {
> +	.driver = {
> +		.name = "it5205",
> +		.of_match_table = it5205_of_table,
> +	},
> +	.probe = it5205_probe,
> +	.remove = it5205_remove,
> +	.id_table = it5205_table,
> +};
> +module_i2c_driver(it5205_driver);
> +
> +MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>");
> +MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
> +MODULE_DESCRIPTION("ITE IT5205 alternate mode passive MUX driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.43.0

-- 
heikki