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SubjectRe: [PATCH v5 12/12] extcon: axp288: Set USB role where necessary
Hi,

Basically, I have no objection. But I'll reply the my ack tag
after finishing the review of 'devcon and usb_role_switch' from USB maintainer.

And I have a question.
Before this patch, extcon-axp288 is used to detect charger connector
and extcon-intel-int3496 is used to detect the USB_HOST connector
on one h/w device?

Best Regards,
Chanwoo Choi
Samsung Electronics

On 2018년 03월 01일 00:07, Hans de Goede wrote:
> The AXP288 BC1.2 charger detection / extcon code may seem like a strange
> place to add code to control the USB role-switch on devices with an AXP288,
> but there are 2 reasons to do this inside the axp288 extcon code:
>
> 1) On many devices the USB role is controlled by ACPI AML code, but the AML
> code only switches between the host and none roles, because of Windows
> not really using device mode. To make device mode work we need to toggle
> between the none/device roles based on Vbus presence, and the axp288
> extcon gets interrupts on Vbus insertion / removal.
>
> 2) In order for our BC1.2 charger detection to work properly the role
> mux must be properly set to device mode before we do the detection.
>
> Also note the Kconfig help-text / obsolete depends on USB_PHY which are
> remnants from older never upstreamed code also controlling the mux from
> the axp288 extcon code.
>
> This commit also adds code to get notifications from the INT3496 extcon
> device, which is used on some devices to notify the kernel about id-pin
> changes instead of them being handled through AML code.
>
> This fixes:
> -Device mode not working on most CHT devices with an AXP288
> -Host mode not working on devices with an INT3496 ACPI device
> -Charger-type misdetection (always SDP) on devices with an INT3496 when the
> USB role (always) gets initialized as host
>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v4:
> -Add Andy's Reviewed-by
>
> Changes in v2:
> -Add depends on X86 to Kconfig (the AXP288 PMIC is only used on X86)
> -Use new acpi_dev_get_first_match_name() helper to get the INT3496 device-name
> -Add Heikki's Reviewed-by
> ---
> drivers/extcon/Kconfig | 3 +-
> drivers/extcon/extcon-axp288.c | 177 +++++++++++++++++++++++++++++++++++++++--
> 2 files changed, 171 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
> index a7bca4207f44..de15bf55895b 100644
> --- a/drivers/extcon/Kconfig
> +++ b/drivers/extcon/Kconfig
> @@ -30,7 +30,8 @@ config EXTCON_ARIZONA
>
> config EXTCON_AXP288
> tristate "X-Power AXP288 EXTCON support"
> - depends on MFD_AXP20X && USB_PHY
> + depends on MFD_AXP20X && USB_SUPPORT && X86
> + select USB_ROLE_SWITCH
> help
> Say Y here to enable support for USB peripheral detection
> and USB MUX switching by X-Power AXP288 PMIC.
> diff --git a/drivers/extcon/extcon-axp288.c b/drivers/extcon/extcon-axp288.c
> index 3ec4c715e240..51e77c7a32c2 100644
> --- a/drivers/extcon/extcon-axp288.c
> +++ b/drivers/extcon/extcon-axp288.c
> @@ -1,6 +1,7 @@
> /*
> * extcon-axp288.c - X-Power AXP288 PMIC extcon cable detection driver
> *
> + * Copyright (c) 2017-2018 Hans de Goede <hdegoede@redhat.com>
> * Copyright (C) 2015 Intel Corporation
> * Author: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
> *
> @@ -14,6 +15,8 @@
> * GNU General Public License for more details.
> */
>
> +#include <linux/acpi.h>
> +#include <linux/connection.h>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <linux/io.h>
> @@ -25,6 +28,11 @@
> #include <linux/extcon-provider.h>
> #include <linux/regmap.h>
> #include <linux/mfd/axp20x.h>
> +#include <linux/usb/role.h>
> +#include <linux/workqueue.h>
> +
> +#include <asm/cpu_device_id.h>
> +#include <asm/intel-family.h>
>
> /* Power source status register */
> #define PS_STAT_VBUS_TRIGGER BIT(0)
> @@ -97,9 +105,19 @@ struct axp288_extcon_info {
> struct device *dev;
> struct regmap *regmap;
> struct regmap_irq_chip_data *regmap_irqc;
> + struct usb_role_switch *role_sw;
> + struct work_struct role_work;
> int irq[EXTCON_IRQ_END];
> struct extcon_dev *edev;
> + struct extcon_dev *id_extcon;
> + struct notifier_block id_nb;
> unsigned int previous_cable;
> + bool vbus_attach;
> +};
> +
> +static const struct x86_cpu_id cherry_trail_cpu_ids[] = {
> + { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_AIRMONT, X86_FEATURE_ANY },
> + {}
> };
>
> /* Power up/down reason string array */
> @@ -137,20 +155,74 @@ static void axp288_extcon_log_rsi(struct axp288_extcon_info *info)
> regmap_write(info->regmap, AXP288_PS_BOOT_REASON_REG, clear_mask);
> }
>
> -static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
> +/*
> + * The below code to control the USB role-switch on devices with an AXP288
> + * may seem out of place, but there are 2 reasons why this is the best place
> + * to control the USB role-switch on such devices:
> + * 1) On many devices the USB role is controlled by AML code, but the AML code
> + * only switches between the host and none roles, because of Windows not
> + * really using device mode. To make device mode work we need to toggle
> + * between the none/device roles based on Vbus presence, and this driver
> + * gets interrupts on Vbus insertion / removal.
> + * 2) In order for our BC1.2 charger detection to work properly the role
> + * mux must be properly set to device mode before we do the detection.
> + */
> +
> +/* Returns the id-pin value, note pulled low / false == host-mode */
> +static bool axp288_get_id_pin(struct axp288_extcon_info *info)
> {
> - int ret, stat, cfg, pwr_stat;
> - u8 chrg_type;
> - unsigned int cable = info->previous_cable;
> - bool vbus_attach = false;
> + enum usb_role role;
> +
> + if (info->id_extcon)
> + return extcon_get_state(info->id_extcon, EXTCON_USB_HOST) <= 0;
> +
> + /* We cannot access the id-pin, see what mode the AML code has set */
> + role = usb_role_switch_get_role(info->role_sw);
> + return role != USB_ROLE_HOST;
> +}
> +
> +static void axp288_usb_role_work(struct work_struct *work)
> +{
> + struct axp288_extcon_info *info =
> + container_of(work, struct axp288_extcon_info, role_work);
> + enum usb_role role;
> + bool id_pin;
> + int ret;
> +
> + id_pin = axp288_get_id_pin(info);
> + if (!id_pin)
> + role = USB_ROLE_HOST;
> + else if (info->vbus_attach)
> + role = USB_ROLE_DEVICE;
> + else
> + role = USB_ROLE_NONE;
> +
> + ret = usb_role_switch_set_role(info->role_sw, role);
> + if (ret)
> + dev_err(info->dev, "failed to set role: %d\n", ret);
> +}
> +
> +static bool axp288_get_vbus_attach(struct axp288_extcon_info *info)
> +{
> + int ret, pwr_stat;
>
> ret = regmap_read(info->regmap, AXP288_PS_STAT_REG, &pwr_stat);
> if (ret < 0) {
> dev_err(info->dev, "failed to read vbus status\n");
> - return ret;
> + return false;
> }
>
> - vbus_attach = (pwr_stat & PS_STAT_VBUS_VALID);
> + return !!(pwr_stat & PS_STAT_VBUS_VALID);
> +}
> +
> +static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
> +{
> + int ret, stat, cfg;
> + u8 chrg_type;
> + unsigned int cable = info->previous_cable;
> + bool vbus_attach = false;
> +
> + vbus_attach = axp288_get_vbus_attach(info);
> if (!vbus_attach)
> goto no_vbus;
>
> @@ -201,6 +273,12 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
> info->previous_cable = cable;
> }
>
> + if (info->role_sw && info->vbus_attach != vbus_attach) {
> + info->vbus_attach = vbus_attach;
> + /* Setting the role can take a while */
> + queue_work(system_long_wq, &info->role_work);
> + }
> +
> return 0;
>
> dev_det_ret:
> @@ -210,6 +288,18 @@ static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
> return ret;
> }
>
> +static int axp288_extcon_id_evt(struct notifier_block *nb,
> + unsigned long event, void *param)
> +{
> + struct axp288_extcon_info *info =
> + container_of(nb, struct axp288_extcon_info, id_nb);
> +
> + /* We may not sleep and setting the role can take a while */
> + queue_work(system_long_wq, &info->role_work);
> +
> + return NOTIFY_OK;
> +}
> +
> static irqreturn_t axp288_extcon_isr(int irq, void *data)
> {
> struct axp288_extcon_info *info = data;
> @@ -231,10 +321,20 @@ static void axp288_extcon_enable(struct axp288_extcon_info *info)
> BC_GLOBAL_RUN, BC_GLOBAL_RUN);
> }
>
> +static void axp288_put_role_sw(void *data)
> +{
> + struct axp288_extcon_info *info = data;
> +
> + cancel_work_sync(&info->role_work);
> + usb_role_switch_put(info->role_sw);
> +}
> +
> static int axp288_extcon_probe(struct platform_device *pdev)
> {
> struct axp288_extcon_info *info;
> struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
> + struct device *dev = &pdev->dev;
> + const char *name;
> int ret, i, pirq;
>
> info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
> @@ -245,9 +345,33 @@ static int axp288_extcon_probe(struct platform_device *pdev)
> info->regmap = axp20x->regmap;
> info->regmap_irqc = axp20x->regmap_irqc;
> info->previous_cable = EXTCON_NONE;
> + INIT_WORK(&info->role_work, axp288_usb_role_work);
> + info->id_nb.notifier_call = axp288_extcon_id_evt;
>
> platform_set_drvdata(pdev, info);
>
> + info->role_sw = usb_role_switch_get(dev);
> + if (IS_ERR(info->role_sw))
> + return PTR_ERR(info->role_sw);
> + if (info->role_sw) {
> + ret = devm_add_action_or_reset(dev, axp288_put_role_sw, info);
> + if (ret)
> + return ret;
> +
> + name = acpi_dev_get_first_match_name("INT3496", NULL, -1);
> + if (name) {
> + info->id_extcon = extcon_get_extcon_dev(name);
> + if (!info->id_extcon)
> + return -EPROBE_DEFER;
> +
> + dev_info(dev, "controlling USB role\n");
> + } else {
> + dev_info(dev, "controlling USB role based on Vbus presence\n");
> + }
> + }
> +
> + info->vbus_attach = axp288_get_vbus_attach(info);
> +
> axp288_extcon_log_rsi(info);
>
> /* Initialize extcon device */
> @@ -289,6 +413,19 @@ static int axp288_extcon_probe(struct platform_device *pdev)
> }
> }
>
> + if (info->id_extcon) {
> + ret = devm_extcon_register_notifier_all(dev, info->id_extcon,
> + &info->id_nb);
> + if (ret)
> + return ret;
> + }
> +
> + /* Make sure the role-sw is set correctly before doing BC detection */
> + if (info->role_sw) {
> + queue_work(system_long_wq, &info->role_work);
> + flush_work(&info->role_work);
> + }
> +
> /* Start charger cable type detection */
> axp288_extcon_enable(info);
>
> @@ -308,8 +445,32 @@ static struct platform_driver axp288_extcon_driver = {
> .name = "axp288_extcon",
> },
> };
> -module_platform_driver(axp288_extcon_driver);
> +
> +static struct devcon axp288_extcon_role_sw_conn = {
> + .endpoint[0] = "axp288_extcon",
> + .endpoint[1] = "intel_xhci_usb_sw-role-switch",
> + .id = "usb-role-switch",
> +};
> +
> +static int __init axp288_extcon_init(void)
> +{
> + if (x86_match_cpu(cherry_trail_cpu_ids))
> + add_device_connection(&axp288_extcon_role_sw_conn);
> +
> + return platform_driver_register(&axp288_extcon_driver);
> +}
> +module_init(axp288_extcon_init);
> +
> +static void __exit axp288_extcon_exit(void)
> +{
> + if (x86_match_cpu(cherry_trail_cpu_ids))
> + remove_device_connection(&axp288_extcon_role_sw_conn);
> +
> + platform_driver_unregister(&axp288_extcon_driver);
> +}
> +module_exit(axp288_extcon_exit);
>
> MODULE_AUTHOR("Ramakrishna Pallala <ramakrishna.pallala@intel.com>");
> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> MODULE_DESCRIPTION("X-Powers AXP288 extcon driver");
> MODULE_LICENSE("GPL v2");
>

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