Re: [PATCH V4 3/7] usb: typec: driver for TI HD3SS3220 USB Type-C DRP port controller

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

On Tue, Apr 16, 2019 at 10:38:03AM +0100, Biju Das wrote:
> Driver for TI HD3SS3220 USB Type-C DRP port controller.
> 
> The driver currently registers the port and supports data role swapping.
> 
> Signed-off-by: Biju Das <biju.das@bp.renesas.com>

It's too bad they call it "port controller" even though it's not Port
Controller Interface compliant. I put a few minor nitpicks below.
Otherwise this looks okay to me, so if there are no other comments:

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

> ---
>  Note: This patch has compilation dependency on 
>  https://patchwork.kernel.org/patch/10882555/
>  
>  V3-->V4
>    * Incorporated Chunfeng Yun's review comment
>    * Used fwnode API's to get usb role switch handle.
>  
>  V2-->V3
>    * Used the new api "usb_role_switch by node" for getting
>      remote endpoint associated with Type-C USB DRP port
>      controller devices.
>  V1-->V2
>    * Driver uses usb role class instead of extcon for dual role switch
>      and also handles connect/disconnect events.
> ---
>  drivers/usb/typec/Kconfig     |  10 ++
>  drivers/usb/typec/Makefile    |   1 +
>  drivers/usb/typec/hd3ss3220.c | 263 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 274 insertions(+)
>  create mode 100644 drivers/usb/typec/hd3ss3220.c
> 
> diff --git a/drivers/usb/typec/Kconfig b/drivers/usb/typec/Kconfig
> index 89d9193..92a3717 100644
> --- a/drivers/usb/typec/Kconfig
> +++ b/drivers/usb/typec/Kconfig
> @@ -50,6 +50,16 @@ source "drivers/usb/typec/tcpm/Kconfig"
>  
>  source "drivers/usb/typec/ucsi/Kconfig"
>  
> +config TYPEC_HD3SS3220
> +	tristate "TI HD3SS3220 Type-C DRP Port controller driver"
> +	depends on I2C
> +	help
> +	  Say Y or M here if your system has TI HD3SS3220 Type-C DRP Port
> +	  controller driver.
> +
> +	  If you choose to build this driver as a dynamically linked module, the
> +	  module will be called hd3ss3220.ko.
> +
>  config TYPEC_TPS6598X
>  	tristate "TI TPS6598x USB Power Delivery controller driver"
>  	depends on I2C
> diff --git a/drivers/usb/typec/Makefile b/drivers/usb/typec/Makefile
> index 6696b72..7753a5c3 100644
> --- a/drivers/usb/typec/Makefile
> +++ b/drivers/usb/typec/Makefile
> @@ -4,5 +4,6 @@ typec-y				:= class.o mux.o bus.o
>  obj-$(CONFIG_TYPEC)		+= altmodes/
>  obj-$(CONFIG_TYPEC_TCPM)	+= tcpm/
>  obj-$(CONFIG_TYPEC_UCSI)	+= ucsi/
> +obj-$(CONFIG_TYPEC_HD3SS3220)	+= hd3ss3220.o
>  obj-$(CONFIG_TYPEC_TPS6598X)	+= tps6598x.o
>  obj-$(CONFIG_TYPEC)		+= mux/
> diff --git a/drivers/usb/typec/hd3ss3220.c b/drivers/usb/typec/hd3ss3220.c
> new file mode 100644
> index 0000000..e98a38f
> --- /dev/null
> +++ b/drivers/usb/typec/hd3ss3220.c
> @@ -0,0 +1,263 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * TI HD3SS3220 Type-C DRP Port Controller Driver
> + *
> + * Copyright (C) 2019 Renesas Electronics Corp.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/usb/role.h>
> +#include <linux/irqreturn.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/usb/typec.h>
> +#include <linux/delay.h>
> +
> +#define HD3SS3220_REG_CN_STAT_CTRL	0x09
> +#define HD3SS3220_REG_GEN_CTRL		0x0A
> +#define HD3SS3220_REG_DEV_REV		0xA0
> +
> +/* Register HD3SS3220_REG_CN_STAT_CTRL*/
> +#define HD3SS3220_REG_CN_STAT_CTRL_ATTACHED_STATE_MASK	(BIT(7) | BIT(6))
> +#define HD3SS3220_REG_CN_STAT_CTRL_AS_DFP		BIT(6)
> +#define HD3SS3220_REG_CN_STAT_CTRL_AS_UFP		BIT(7)
> +#define HD3SS3220_REG_CN_STAT_CTRL_TO_ACCESSORY		(BIT(7) | BIT(6))
> +#define HD3SS3220_REG_CN_STAT_CTRL_INT_STATUS		BIT(4)
> +
> +/* Register HD3SS3220_REG_GEN_CTRL*/
> +#define HD3SS3220_REG_GEN_CTRL_SRC_PREF_MASK		(BIT(2) | BIT(1))
> +#define HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_DEFAULT	0x00
> +#define HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SNK	BIT(1)
> +#define HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SRC	(BIT(2) | BIT(1))
> +
> +struct hd3ss3220 {
> +	struct device *dev;
> +	struct regmap *regmap;
> +	struct usb_role_switch	*role_sw;
> +	struct typec_port *port;
> +	struct typec_capability typec_cap;
> +};
> +
> +static int hd3ss3220_set_source_pref(struct hd3ss3220 *hd3ss3220, int src_pref)
> +{
> +	return regmap_update_bits(hd3ss3220->regmap, HD3SS3220_REG_GEN_CTRL,
> +				  HD3SS3220_REG_GEN_CTRL_SRC_PREF_MASK,
> +				  src_pref);
> +}
> +
> +static enum usb_role hd3ss3220_get_attached_state(struct hd3ss3220 *hd3ss3220)
> +{
> +	unsigned int reg_val;
> +	enum usb_role attached_state;
> +	int ret;
> +
> +	ret = regmap_read(hd3ss3220->regmap, HD3SS3220_REG_CN_STAT_CTRL,
> +			  &reg_val);
> +	if (ret < 0)
> +		return ret;
> +
> +	switch (reg_val & HD3SS3220_REG_CN_STAT_CTRL_ATTACHED_STATE_MASK) {
> +	case HD3SS3220_REG_CN_STAT_CTRL_AS_DFP:
> +		attached_state = USB_ROLE_HOST;
> +	break;
> +	case HD3SS3220_REG_CN_STAT_CTRL_AS_UFP:
> +		attached_state = USB_ROLE_DEVICE;
> +	break;

It looks like your line indentation has collapsed here. I pretty sure
scripts/checkpatch.pl would have found these.

> +	default:
> +		attached_state = USB_ROLE_NONE;
> +	}
> +
> +	return attached_state;
> +}
> +
> +static int hd3ss3220_dr_set(const struct typec_capability *cap,
> +			    enum typec_data_role role)
> +{
> +	struct hd3ss3220 *hd3ss3220 = container_of(cap, struct hd3ss3220,
> +						   typec_cap);
> +	enum usb_role role_val;
> +	int pref, ret = 0;
> +
> +	if (role == TYPEC_HOST) {
> +		role_val = USB_ROLE_HOST;
> +		pref = HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SRC;
> +	} else {
> +		role_val = USB_ROLE_DEVICE;
> +		pref = HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SNK;
> +	}
> +
> +	ret = hd3ss3220_set_source_pref(hd3ss3220, pref);
> +	usleep_range(10, 100);
> +
> +	usb_role_switch_set_role(hd3ss3220->role_sw, role_val);
> +	typec_set_data_role(hd3ss3220->port, role);
> +
> +	return ret;
> +}
> +
> +static void hd3ss3220_set_role(struct hd3ss3220 *hd3ss3220)
> +{
> +	enum usb_role role_state = hd3ss3220_get_attached_state(hd3ss3220);
> +
> +	usb_role_switch_set_role(hd3ss3220->role_sw, role_state);
> +	if (role_state == USB_ROLE_NONE)
> +		hd3ss3220_set_source_pref(hd3ss3220,
> +				HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_DEFAULT);
> +
> +	switch (role_state) {
> +	case USB_ROLE_HOST:
> +		typec_set_data_role(hd3ss3220->port, TYPEC_HOST);
> +		break;
> +	case USB_ROLE_DEVICE:
> +		typec_set_data_role(hd3ss3220->port, TYPEC_DEVICE);
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
> +irqreturn_t hd3ss3220_irq(struct hd3ss3220 *hd3ss3220)
> +{
> +	int err;
> +
> +	hd3ss3220_set_role(hd3ss3220);
> +	err = regmap_update_bits_base(hd3ss3220->regmap,
> +				      HD3SS3220_REG_CN_STAT_CTRL,
> +				      HD3SS3220_REG_CN_STAT_CTRL_INT_STATUS,
> +				      HD3SS3220_REG_CN_STAT_CTRL_INT_STATUS,
> +				      NULL, false, true);
> +	if (err < 0)
> +		return IRQ_NONE;
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t hd3ss3220_irq_handler(int irq, void *data)
> +{
> +	struct i2c_client *client = to_i2c_client(data);
> +	struct hd3ss3220 *hd3ss3220 = i2c_get_clientdata(client);
> +
> +	return hd3ss3220_irq(hd3ss3220);
> +}
> +
> +static const struct regmap_config config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0x0A,
> +};
> +
> +static int hd3ss3220_probe(struct i2c_client *client,
> +		const struct i2c_device_id *id)
> +{
> +	struct hd3ss3220 *hd3ss3220;
> +	struct fwnode_handle *parent, *child;
> +	int ret;
> +	unsigned int data;
> +
> +	hd3ss3220 = devm_kzalloc(&client->dev, sizeof(struct hd3ss3220),
> +				 GFP_KERNEL);
> +	if (!hd3ss3220)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(client, hd3ss3220);
> +
> +	hd3ss3220->dev = &client->dev;
> +	hd3ss3220->regmap = devm_regmap_init_i2c(client, &config);
> +	if (IS_ERR(hd3ss3220->regmap))
> +		return PTR_ERR(hd3ss3220->regmap);
> +
> +	hd3ss3220_set_source_pref(hd3ss3220,
> +				  HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_DEFAULT);
> +	child = fwnode_graph_get_next_endpoint(dev_fwnode(hd3ss3220->dev),
> +					       NULL);
> +	parent = fwnode_graph_get_remote_port_parent(child);
> +	hd3ss3220->role_sw = fwnode_usb_role_switch_get(parent);
> +	if (IS_ERR_OR_NULL(hd3ss3220->role_sw)) {
> +		fwnode_handle_put(child);
> +		fwnode_handle_put(parent);
> +		return PTR_ERR(hd3ss3220->role_sw);
> +	}
> +
> +	fwnode_handle_put(child);
> +	fwnode_handle_put(parent);
> +
> +	hd3ss3220->typec_cap.prefer_role = TYPEC_NO_PREFERRED_ROLE;
> +	hd3ss3220->typec_cap.dr_set = hd3ss3220_dr_set;
> +	hd3ss3220->typec_cap.type = TYPEC_PORT_DRP;
> +	hd3ss3220->typec_cap.data = TYPEC_PORT_DRD;
> +
> +	hd3ss3220->port = typec_register_port(&client->dev,
> +					      &hd3ss3220->typec_cap);
> +	if (IS_ERR(hd3ss3220->port))
> +		return PTR_ERR(hd3ss3220->port);
> +
> +	hd3ss3220_set_role(hd3ss3220);
> +	if (client->irq > 0) {
> +		ret = regmap_read(hd3ss3220->regmap, HD3SS3220_REG_CN_STAT_CTRL,
> +				  &data);
> +		if (ret < 0)
> +			goto error;
> +
> +		if (data & HD3SS3220_REG_CN_STAT_CTRL_INT_STATUS) {
> +			ret = regmap_write(hd3ss3220->regmap,
> +				HD3SS3220_REG_CN_STAT_CTRL,
> +				data | HD3SS3220_REG_CN_STAT_CTRL_INT_STATUS);
> +			if (ret < 0)
> +				goto error;
> +		}
> +		if (data & HD3SS3220_REG_CN_STAT_CTRL_INT_STATUS) {
> +			ret = regmap_write(hd3ss3220->regmap,
> +				HD3SS3220_REG_CN_STAT_CTRL,
> +				data | HD3SS3220_REG_CN_STAT_CTRL_INT_STATUS);
> +			if (ret < 0)
> +				goto error;
> +		}
> +
> +		ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> +					hd3ss3220_irq_handler,
> +					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> +					"hd3ss3220", &client->dev);
> +		if (ret)
> +			goto error;
> +	}

I would move the above if (client->irq > 0) case to it's own function.

> +	ret = i2c_smbus_read_byte_data(client, HD3SS3220_REG_DEV_REV);
> +	if (ret < 0)
> +		goto error;
> +
> +	dev_info(&client->dev, "probed revision=0x%x\n", ret);
> +
> +	return 0;
> +error:
> +	typec_unregister_port(hd3ss3220->port);
> +	usb_role_switch_put(hd3ss3220->role_sw);
> +
> +	return ret;
> +}
> +
> +static int hd3ss3220_remove(struct i2c_client *client)
> +{
> +	struct hd3ss3220 *hd3ss3220 = i2c_get_clientdata(client);
> +
> +	typec_unregister_port(hd3ss3220->port);
> +	usb_role_switch_put(hd3ss3220->role_sw);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id dev_ids[] = {
> +	{ .compatible = "ti,hd3ss3220"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, dev_ids);
> +
> +static struct i2c_driver hd3ss3220_driver = {
> +	.driver = {
> +		.name = "hd3ss3220",
> +		.of_match_table = of_match_ptr(dev_ids),
> +	},
> +	.probe = hd3ss3220_probe,
> +	.remove =  hd3ss3220_remove,
> +};
> +
> +module_i2c_driver(hd3ss3220_driver);
> +
> +MODULE_AUTHOR("Biju Das <biju.das@bp.renesas.com>");
> +MODULE_DESCRIPTION("TI HD3SS3220 DRP Port Controller Driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.7.4

thanks,

-- 
heikki