From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Hans de Goede <hdegoede@redhat.com>
Cc: Darren Hart <dvhart@infradead.org>,
Andy Shevchenko <andy@infradead.org>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
Mathias Nyman <mathias.nyman@intel.com>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Platform Driver <platform-driver-x86@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
USB <linux-usb@vger.kernel.org>
Subject: Re: [PATCH 09/12] usb: roles: Add Intel XHCI USB role switch driver
Date: Fri, 16 Feb 2018 15:47:04 +0200 [thread overview]
Message-ID: <CAHp75VfnqbSecz4y-ThLRPVjTe6jrBPgwEnGEuxb6AunvNDvvg@mail.gmail.com> (raw)
In-Reply-To: <20180216104751.8371-10-hdegoede@redhat.com>
On Fri, Feb 16, 2018 at 12:47 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> Various Intel SoCs (Cherry Trail, Broxton and others) have an internal USB
> role switch for swiching the OTG USB data lines between the xHCI host
> controller and the dwc3 gadget controller.
>
> Note on some Cherry Trail systems there is ACPI/AML code listening to
> edge interrupts on the id-pin (through an _AIE ACPI method) and switching
> the role between ROLE_HOST and ROLE_NONE based on the id-pin. Note it does
> not set the role to ROLE_DEVICE, because device-mode is usually not used
> under Windows.
>
> The presence of AML code which modifies the cfg0 reg (on some systems)
> means that we our read/write/modify of cfg0 may race with the AML code
> doing the same to avoid this we take the global ACPI lock while doing
> the read/write/modify.
> +/* register definition */
> +#define DUAL_ROLE_CFG0 0x68
> +#define SW_VBUS_VALID (1 << 24)
> +#define SW_IDPIN_EN (1 << 21)
> +#define SW_IDPIN (1 << 20)
> +
> +#define DUAL_ROLE_CFG1 0x6c
> +#define HOST_MODE (1 << 29)
Does it make sense to use BIT() macro above?
> +struct intel_xhci_acpi_match {
> + const char *hid;
> + int hrv;
> +};
Consider to unify with struct acpi_ac_bl.
> +static const struct intel_xhci_acpi_match allow_userspace_ctrl_ids[] = {
> + { "INT33F4", 3 }, /* X-Powers AXP288 PMIC */
> +};
> +
> +static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
> +{
> + struct intel_xhci_usb_data *data = dev_get_drvdata(dev);
> + unsigned long timeout;
> + acpi_status status;
> + u32 glk = -1U;
I prefer to see consistency and moreover less confusing set, like
~0U
> + u32 val;
> +
> + /*
> + * On many CHT devices ACPI event (_AEI) handlers read / modify /
> + * write the cfg0 register, just like we do. Take the ACPI lock
> + * to avoid us racing with the AML code.
> + */
> + status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
FOREVER?!
Wouldn't be slightly long under certain circumstances?
> + if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
> + dev_err(dev, "Error could not acquire lock\n");
> + return -EIO;
> + }
> + acpi_release_global_lock(glk);
> + /* Polling on CFG1 register to confirm mode switch.*/
> + do {
> + val = readl(data->base + DUAL_ROLE_CFG1);
> + if (!!(val & HOST_MODE) == (role == USB_ROLE_HOST))
I would prefer ^ instead of first ==, but it's up to you.
> + return 0;
> +
> + /* Interval for polling is set to about 5 - 10 ms */
> + usleep_range(5000, 10000);
> + } while (time_before(jiffies, timeout));
> +
> + dev_warn(dev, "Timeout waiting for role-switch\n");
> + return -ETIMEDOUT;
> +}
> +static int intel_xhci_usb_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct intel_xhci_usb_data *data;
> + struct resource *res;
> + resource_size_t size;
> + int i, ret;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + size = (res->end + 1) - res->start;
resource_size()
> + data->base = devm_ioremap_nocache(dev, res->start, size);
So, what's wrong with devm_ioremap_resource() ?
...which also prints an error message.
> + if (IS_ERR(data->base)) {
> + ret = PTR_ERR(data->base);
> + dev_err(dev, "Error iomaping registers: %d\n", ret);
At least printing return code is useless. Driver core does this.
> + return ret;
> + }
> +
> + data->role_sw = usb_role_switch_register(dev, &sw_desc);
> + if (IS_ERR(data->role_sw)) {
> + ret = PTR_ERR(data->role_sw);
> + dev_err(dev, "Error registering role-switch: %d\n", ret);
Ditto.
> + return ret;
> + }
> +
> + return 0;
> +}
> +static const struct platform_device_id intel_xhci_usb_table[] = {
> + { .name = DRV_NAME },
> + {},
No comma, please.
> +};
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2018-02-16 13:47 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-16 10:47 [PATCH 00/12] USB Type-C device-connection, mux and switch support Hans de Goede
2018-02-16 10:47 ` [PATCH 01/12] drivers: base: Unified device connection lookup Hans de Goede
2018-02-16 11:00 ` Andy Shevchenko
2018-02-16 11:21 ` Hans de Goede
2018-02-16 11:28 ` Heikki Krogerus
2018-02-16 10:47 ` [PATCH 02/12] usb: typec: Start using ERR_PTR Hans de Goede
2018-02-16 11:07 ` Andy Shevchenko
2018-02-16 11:21 ` Hans de Goede
2018-02-16 10:47 ` [PATCH 03/12] usb: typec: API for controlling USB Type-C Multiplexers Hans de Goede
2018-02-16 14:00 ` Andy Shevchenko
2018-02-25 12:13 ` Hans de Goede
2018-02-16 10:47 ` [PATCH 04/12] usb: common: Small class for USB role switches Hans de Goede
2018-02-16 14:07 ` Andy Shevchenko
2018-02-16 14:22 ` Heikki Krogerus
2018-02-19 9:32 ` Hans de Goede
2018-02-25 12:16 ` Hans de Goede
2018-02-16 18:33 ` Randy Dunlap
2018-02-25 12:16 ` Hans de Goede
2018-02-16 10:47 ` [PATCH 05/12] usb: typec: tcpm: Set USB role switch to device mode when configured as such Hans de Goede
2018-02-16 13:19 ` Heikki Krogerus
2018-02-16 10:47 ` [PATCH 06/12] usb: typec: tcpm: Use new Type-C switch/mux and usb-role-switch functions Hans de Goede
2018-02-16 13:20 ` Heikki Krogerus
2018-02-16 10:47 ` [PATCH 07/12] xhci: Add option to get next extended capability in list by passing id = 0 Hans de Goede
2018-02-16 13:21 ` Heikki Krogerus
2018-02-16 10:47 ` [PATCH 08/12] xhci: Add Intel extended cap / otg phy mux handling Hans de Goede
2018-02-16 13:32 ` Heikki Krogerus
2018-02-16 13:53 ` Andy Shevchenko
2018-02-25 13:01 ` Hans de Goede
2018-02-16 10:47 ` [PATCH 09/12] usb: roles: Add Intel XHCI USB role switch driver Hans de Goede
2018-02-16 13:38 ` Heikki Krogerus
2018-02-25 12:11 ` Hans de Goede
2018-02-16 13:47 ` Andy Shevchenko [this message]
2018-02-25 13:29 ` Hans de Goede
2018-02-16 10:47 ` [PATCH 10/12] usb: typec: driver for Pericom PI3USB30532 Type-C cross switch Hans de Goede
2018-02-16 13:33 ` Andy Shevchenko
2018-02-16 13:43 ` Heikki Krogerus
2018-02-16 10:47 ` [PATCH 11/12] platform/x86: intel_cht_int33fe: Add device connections for the Type-C port Hans de Goede
2018-02-16 13:10 ` Andy Shevchenko
2018-02-16 13:43 ` Heikki Krogerus
2018-02-16 10:47 ` [PATCH 12/12] extcon: axp288: Set USB role where necessary Hans de Goede
2018-02-16 13:19 ` Andy Shevchenko
2018-02-25 13:49 ` Hans de Goede
2018-02-16 13:45 ` Heikki Krogerus
2018-02-16 13:36 ` [PATCH 00/12] USB Type-C device-connection, mux and switch support Andy Shevchenko
-- strict thread matches above, loose matches on Subject: below --
2018-02-16 10:43 [PATCH 0/12] " Hans de Goede
2018-02-16 10:43 ` [PATCH 09/12] usb: roles: Add Intel XHCI USB role switch driver Hans de Goede
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