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Date:   Tue, 9 Jun 2020 18:20:27 -0700
From:   Jack Pham <jackp@codeaurora.org>
To:     Wesley Cheng <wcheng@codeaurora.org>
Cc:     heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org,
        mark.rutland@arm.com, robh+dt@kernel.org, agross@kernel.org,
        bjorn.andersson@linaro.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-usb@vger.kernel.org, bryan.odonoghue@linaro.org
Subject: Re: [PATCH 1/3] usb: typec: Add QCOM PMIC typec detection driver
Message-ID: <20200610011837.GA14816@jackp-linux.qualcomm.com>
References: <20200609205851.30113-1-wcheng@codeaurora.org>
 <20200609205851.30113-2-wcheng@codeaurora.org>
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In-Reply-To: <20200609205851.30113-2-wcheng@codeaurora.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
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Hi Wesley,

On Tue, Jun 09, 2020 at 01:58:49PM -0700, Wesley Cheng wrote:
> The QCOM SPMI typec driver handles the role and orientation detection, and
> notifies client drivers using the USB role switch framework.   It registers
> as a typec port, so orientation can be communicated using the typec switch
> APIs.  The driver also registers the VBUS output regulator, so client

Doesn't look like it.. As we discussed in earlier revisions we decided
to drop the regulator.

> drivers can enable the VBUS source when acting as a source/host.
> 
> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
> ---
>  drivers/usb/typec/Kconfig           |  11 ++
>  drivers/usb/typec/Makefile          |   1 +
>  drivers/usb/typec/qcom-pmic-typec.c | 278 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 290 insertions(+)
>  create mode 100644 drivers/usb/typec/qcom-pmic-typec.c
> 
> diff --git a/drivers/usb/typec/Kconfig b/drivers/usb/typec/Kconfig
> index 559dd06..8de2520 100644
> --- a/drivers/usb/typec/Kconfig
> +++ b/drivers/usb/typec/Kconfig
> @@ -73,6 +73,17 @@ config TYPEC_TPS6598X
>  	  If you choose to build this driver as a dynamically linked module, the
>  	  module will be called tps6598x.ko.
>  
> +config TYPEC_QCOM_PMIC
> +	tristate "Qualcomm PMIC USB typec driver"
> +	depends on ARCH_QCOM
> +	help
> +	  Driver for supporting role switch over the Qualcomm PMIC.  This will
> +	  handle the type C role and orientation detection reported by the QCOM
> +	  PMIC if the PMIC has the capability to handle type C detection.
> +
> +	  It will also enable the VBUS output to connected devices when a
> +	  DFP connection is made.
> +
>  source "drivers/usb/typec/mux/Kconfig"
>  
>  source "drivers/usb/typec/altmodes/Kconfig"
> diff --git a/drivers/usb/typec/Makefile b/drivers/usb/typec/Makefile
> index 7753a5c3..cceffd9 100644
> --- a/drivers/usb/typec/Makefile
> +++ b/drivers/usb/typec/Makefile
> @@ -6,4 +6,5 @@ obj-$(CONFIG_TYPEC_TCPM)	+= tcpm/
>  obj-$(CONFIG_TYPEC_UCSI)	+= ucsi/
>  obj-$(CONFIG_TYPEC_HD3SS3220)	+= hd3ss3220.o
>  obj-$(CONFIG_TYPEC_TPS6598X)	+= tps6598x.o
> +obj-$(CONFIG_TYPEC_QCOM_PMIC)	+= qcom-pmic-typec.o
>  obj-$(CONFIG_TYPEC)		+= mux/
> diff --git a/drivers/usb/typec/qcom-pmic-typec.c b/drivers/usb/typec/qcom-pmic-typec.c
> new file mode 100644
> index 0000000..ce6319c
> --- /dev/null
> +++ b/drivers/usb/typec/qcom-pmic-typec.c
> @@ -0,0 +1,278 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2020, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/regmap.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/of_device.h>
> +#include <linux/usb/role.h>
> +#include <linux/usb/typec_mux.h>
> +#include <linux/workqueue.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/regulator/driver.h>
> +#include <linux/regulator/machine.h>
> +
> +#define DCDC_BASE			0x1100

along with USB_BASE @ 0x1300, is it ok to allow this driver to access
registers outside of its 'reg' base (0x1500 according to the DT
bindings)?

> +#define CMD_OTG				(DCDC_BASE + 0x40)
> +#define OTG_EN				BIT(0)
> +#define OTG_CFG				(DCDC_BASE + 0x53)
> +#define OTG_EN_SRC_CFG			BIT(1)
> +
> +#define USB_BASE			0x1300
> +#define TYPE_C_CFG_REG			(USB_BASE + 0x58)
> +#define BC12_START_ON_CC		BIT(7)
> +
> +#define TYPEC_BASE			0x1500
> +#define TYPEC_MISC_STATUS		(TYPEC_BASE + 0xb)
> +#define CC_ATTACHED			BIT(0)
> +#define CC_ORIENTATION			BIT(1)
> +#define SNK_SRC_MODE			BIT(6)
> +#define TYPEC_MODE_CFG			(TYPEC_BASE + 0x44)
> +#define TYPEC_DISABLE_CMD		BIT(0)
> +#define EN_SNK_ONLY			BIT(1)
> +#define EN_SRC_ONLY			BIT(2)
> +#define EN_TRY_SNK			BIT(4)
> +#define TYPEC_VCONN_CONTROL		(TYPEC_BASE + 0x46)
> +#define VCONN_EN_SRC			BIT(0)
> +#define VCONN_EN_VAL			BIT(1)
> +#define TYPEC_EXIT_STATE_CFG		(TYPEC_BASE + 0x50)
> +#define SEL_SRC_UPPER_REF		BIT(2)
> +#define TYPEC_INTR_EN_CFG_1		(TYPEC_BASE + 0x5e)
> +#define TYPEC_INTR_EN_CFG_1_MASK	GENMASK(0, 7)
> +
> +struct qcom_pmic_typec {
> +	struct device		*dev;
> +	struct fwnode_handle	*fwnode;
> +	struct regmap		*regmap;
> +	struct work_struct	bh_work;
> +
> +	struct typec_capability *cap;
> +	struct typec_port	*port;
> +	struct usb_role_switch *role_sw;
> +
> +	struct regulator_desc usb_vbus_rdesc;
> +	struct regulator_dev *usb_vbus_reg;

These aren't used...leftovers from earlier revisions?

> +};
> +
> +static int qcom_pmic_typec_vbus_enable(struct qcom_pmic_typec *qcom_usb)
> +{
> +	int rc;
> +
> +	rc = regmap_update_bits(qcom_usb->regmap, CMD_OTG, OTG_EN, OTG_EN);
> +	if (rc)
> +		dev_err(qcom_usb->dev, "failed to update OTG_CTL\n");
> +
> +	return rc;
> +}
> +
> +static int qcom_pmic_typec_vbus_disable(struct qcom_pmic_typec *qcom_usb)
> +{
> +	int rc;
> +
> +	rc = regmap_update_bits(qcom_usb->regmap, CMD_OTG, OTG_EN, 0);
> +	if (rc)
> +		dev_err(qcom_usb->dev, "failed to update OTG_CTL\n");
> +
> +	return rc;
> +}
> +
> +void qcom_pmic_typec_bh_work(struct work_struct *w)
> +{
> +	struct qcom_pmic_typec *qcom_usb = container_of(w,
> +							struct qcom_pmic_typec,
> +							bh_work);
> +	enum typec_orientation orientation;
> +	enum usb_role role;
> +	unsigned int stat;
> +
> +	regmap_read(qcom_usb->regmap, TYPEC_MISC_STATUS, &stat);
> +
> +	if (stat & CC_ATTACHED) {
> +		orientation = ((stat & CC_ORIENTATION) >> 1) ?
> +				TYPEC_ORIENTATION_REVERSE :
> +				TYPEC_ORIENTATION_NORMAL;
> +		typec_set_orientation(qcom_usb->port, orientation);
> +
> +		role = (stat & SNK_SRC_MODE) ? USB_ROLE_HOST : USB_ROLE_DEVICE;
> +		if (role == USB_ROLE_HOST)
> +			qcom_pmic_typec_vbus_enable(qcom_usb);
> +		else
> +			qcom_pmic_typec_vbus_disable(qcom_usb);
> +
> +		usb_role_switch_set_role(qcom_usb->role_sw, role);
> +	} else {
> +		usb_role_switch_set_role(qcom_usb->role_sw, USB_ROLE_NONE);
> +		qcom_pmic_typec_vbus_disable(qcom_usb);
> +	}
> +}
> +
> +irqreturn_t qcom_pmic_typec_interrupt(int irq, void *_qcom_usb)
> +{
> +	struct qcom_pmic_typec *qcom_usb = _qcom_usb;
> +
> +	queue_work(system_power_efficient_wq, &qcom_usb->bh_work);

Do we really need a workqueue function here or would a threaded IRQ
handler work?

> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void qcom_pmic_typec_typec_hw_init(struct qcom_pmic_typec *qcom_usb)
> +{
> +	u8 mode;
> +
> +	regmap_update_bits(qcom_usb->regmap, TYPE_C_CFG_REG, BC12_START_ON_CC,
> +			   0);
> +	regmap_update_bits(qcom_usb->regmap, TYPEC_INTR_EN_CFG_1,
> +			   TYPEC_INTR_EN_CFG_1_MASK, 0);
> +
> +	if (qcom_usb->cap->type != TYPEC_PORT_DRP)
> +		mode = (qcom_usb->cap->type == TYPEC_PORT_SNK) ?
> +					EN_SNK_ONLY : EN_SRC_ONLY;
> +	else
> +		mode = EN_TRY_SNK;
> +	regmap_update_bits(qcom_usb->regmap, TYPEC_MODE_CFG,
> +			   EN_SNK_ONLY | EN_TRY_SNK | EN_SRC_ONLY, mode);

HW also has an EN_TRY_SRC bit too. Would these EN_TRY_{SRC,SNK} bits
happen to be compatible with the struct typec's try_role() at all?

> +
> +	regmap_update_bits(qcom_usb->regmap, TYPEC_VCONN_CONTROL,
> +			   VCONN_EN_SRC | VCONN_EN_VAL, VCONN_EN_SRC);
> +	regmap_update_bits(qcom_usb->regmap, TYPEC_VCONN_CONTROL,
> +			   VCONN_EN_SRC | VCONN_EN_VAL, VCONN_EN_SRC);

duplicated?

> +	regmap_update_bits(qcom_usb->regmap, TYPEC_EXIT_STATE_CFG,
> +			   SEL_SRC_UPPER_REF, SEL_SRC_UPPER_REF);
> +	regmap_update_bits(qcom_usb->regmap, OTG_CFG, OTG_EN_SRC_CFG,
> +			   OTG_EN_SRC_CFG);

I thought setting this OTG_EN_SRC_CFG bit makes the VBUS boost
controlled by HW, thereby negating the need for
qcom_pmic_typec_vbus_enable/disable ?

Thanks,
Jack

> +}
> +
> +static int qcom_pmic_typec_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct qcom_pmic_typec *qcom_usb;
> +	struct typec_capability *cap;
> +	const char *buf;
> +	int ret, irq, role;
> +
> +	qcom_usb = kzalloc(sizeof(*qcom_usb), GFP_KERNEL);
> +	if (!qcom_usb)
> +		return -ENOMEM;
> +
> +	qcom_usb->dev = dev;
> +
> +	qcom_usb->regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!qcom_usb->regmap) {
> +		dev_err(dev, "Failed to get regmap\n");
> +		return -EINVAL;
> +	}
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		dev_err(dev, "Failed to get CC irq\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = devm_request_irq(qcom_usb->dev, irq, qcom_pmic_typec_interrupt,
> +			       IRQF_SHARED, "qcom-pmic-typec", qcom_usb);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Could not request IRQ\n");
> +		return ret;
> +	}
> +
> +	qcom_usb->fwnode = device_get_named_child_node(dev, "connector");
> +	if (!qcom_usb->fwnode)
> +		return -EINVAL;
> +
> +	cap = kzalloc(sizeof(*cap), GFP_KERNEL);
> +	if (!cap) {
> +		ret = -ENOMEM;
> +		goto err_put_node;
> +	}
> +
> +	ret = fwnode_property_read_string(qcom_usb->fwnode, "power-role", &buf);
> +	if (!ret)
> +		role = typec_find_port_power_role(buf);
> +	else
> +		role = TYPEC_PORT_SNK;
> +	cap->type = role;
> +
> +	ret = fwnode_property_read_string(qcom_usb->fwnode, "data-role", &buf);
> +	if (!ret)
> +		role = typec_find_port_data_role(buf);
> +	else
> +		role = TYPEC_PORT_UFP;
> +	cap->data = role;
> +
> +	cap->prefer_role = -1;
> +	cap->fwnode = qcom_usb->fwnode;
> +	qcom_usb->port = typec_register_port(dev, cap);
> +	if (IS_ERR(qcom_usb->port)) {
> +		dev_err(dev, "Failed to register type c port %d\n",
> +			IS_ERR(qcom_usb->port));
> +		ret = PTR_ERR(qcom_usb->port);
> +		goto err_put_node;
> +	}
> +
> +	qcom_usb->cap = cap;
> +
> +	qcom_usb->role_sw = fwnode_usb_role_switch_get(qcom_usb->fwnode);
> +	if (IS_ERR(qcom_usb->role_sw)) {
> +		if (PTR_ERR(qcom_usb->role_sw) != -EPROBE_DEFER)
> +			dev_err(dev, "failed to get role switch\n");
> +		ret = PTR_ERR(qcom_usb->role_sw);
> +		goto err_typec_port;
> +	}
> +
> +	INIT_WORK(&qcom_usb->bh_work, qcom_pmic_typec_bh_work);
> +	platform_set_drvdata(pdev, qcom_usb);
> +	qcom_pmic_typec_typec_hw_init(qcom_usb);
> +
> +	queue_work(system_power_efficient_wq, &qcom_usb->bh_work);
> +
> +	return 0;
> +
> +err_typec_port:
> +	typec_unregister_port(qcom_usb->port);
> +err_put_node:
> +	fwnode_handle_put(qcom_usb->fwnode);
> +
> +	return ret;
> +}
> +
> +static int qcom_pmic_typec_remove(struct platform_device *pdev)
> +{
> +	struct qcom_pmic_typec *qcom_usb = platform_get_drvdata(pdev);
> +
> +	cancel_work_sync(&qcom_usb->bh_work);
> +	usb_role_switch_set_role(qcom_usb->role_sw, USB_ROLE_NONE);
> +	qcom_pmic_typec_vbus_disable(qcom_usb);
> +
> +	typec_unregister_port(qcom_usb->port);
> +	usb_role_switch_put(qcom_usb->role_sw);
> +	fwnode_handle_put(qcom_usb->fwnode);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id qcom_pmic_typec_table[] = {
> +	{ .compatible = "qcom,pm8150b-usb-typec" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, qcom_pmic_typec_table);
> +
> +static struct platform_driver qcom_pmic_typec = {
> +	.driver = {
> +		.name = "qcom,pmic-typec",
> +		.of_match_table = qcom_pmic_typec_table,
> +	},
> +	.probe = qcom_pmic_typec_probe,
> +	.remove = qcom_pmic_typec_remove,
> +};
> +
> +module_platform_driver(qcom_pmic_typec);
> +
> +MODULE_DESCRIPTION("QCOM PMIC USB type C driver");
> +MODULE_LICENSE("GPL v2");
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