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Message-ID: <fc9ec62d-50b7-7d29-cea4-83378211f629@lechnology.com>
Date: Tue, 22 Nov 2016 14:37:17 -0600
From: David Lechner <david@...hnology.com>
To: Axel Haslam <ahaslam@...libre.com>, gregkh@...uxfoundation.org,
nsekhar@...com, khilman@...libre.com
Cc: linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org
Subject: Re: [PATCH v6 3/5] USB: ohci: da8xx: Allow a regulator to handle VBUS
On 11/21/2016 10:30 AM, Axel Haslam wrote:
> Using a regulator to handle VBUS will eliminate the need for
> platform data and callbacks, and make the driver more generic
> allowing different types of regulators to handle VBUS.
>
> The regulator equivalents to the platform callbacks are:
> set_power -> regulator_enable/regulator_disable
> get_power -> regulator_is_enabled
> get_oci -> regulator_get_error_flags
> ocic_notify -> regulator event notification
>
> Signed-off-by: Axel Haslam <ahaslam@...libre.com>
> ---
> drivers/usb/host/ohci-da8xx.c | 97 +++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 94 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/host/ohci-da8xx.c b/drivers/usb/host/ohci-da8xx.c
> index 90763ad..d0eb754 100644
> --- a/drivers/usb/host/ohci-da8xx.c
> +++ b/drivers/usb/host/ohci-da8xx.c
> @@ -20,6 +20,7 @@
> #include <linux/platform_device.h>
> #include <linux/phy/phy.h>
> #include <linux/platform_data/usb-davinci.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/usb.h>
> #include <linux/usb/hcd.h>
> #include <asm/unaligned.h>
> @@ -36,8 +37,12 @@ static int (*orig_ohci_hub_control)(struct usb_hcd *hcd, u16 typeReq,
> static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);
>
> struct da8xx_ohci_hcd {
> + struct usb_hcd *hcd;
> struct clk *usb11_clk;
> struct phy *usb11_phy;
> + struct regulator *vbus_reg;
> + struct notifier_block nb;
> + unsigned int reg_enabled;
> };
>
> #define to_da8xx_ohci(hcd) (struct da8xx_ohci_hcd *)(hcd_to_ohci(hcd)->priv)
> @@ -83,56 +88,103 @@ static void ohci_da8xx_disable(struct usb_hcd *hcd)
>
> static int ohci_da8xx_set_power(struct usb_hcd *hcd, int on)
> {
> + struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
> struct device *dev = hcd->self.controller;
> struct da8xx_ohci_root_hub *hub = dev_get_platdata(dev);
> + int ret;
>
> if (hub && hub->set_power)
> return hub->set_power(1, on);
>
> + if (!da8xx_ohci->vbus_reg)
> + return 0;
> +
> + if (on && !da8xx_ohci->reg_enabled) {
> + ret = regulator_enable(da8xx_ohci->vbus_reg);
> + if (ret) {
> + dev_err(dev, "Failed to enable regulator: %d\n", ret);
> + return ret;
> + }
> + da8xx_ohci->reg_enabled = 1;
> +
> + } else if (!on && da8xx_ohci->reg_enabled) {
> + ret = regulator_disable(da8xx_ohci->vbus_reg);
> + if (ret) {
> + dev_err(dev, "Failed to disable regulator: %d\n", ret);
> + return ret;
> + }
> + da8xx_ohci->reg_enabled = 0;
> + }
> +
> return 0;
> }
>
> static int ohci_da8xx_get_power(struct usb_hcd *hcd)
> {
> + struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
> struct device *dev = hcd->self.controller;
> struct da8xx_ohci_root_hub *hub = dev_get_platdata(dev);
>
> if (hub && hub->get_power)
> return hub->get_power(1);
>
> + if (da8xx_ohci->vbus_reg)
> + return regulator_is_enabled(da8xx_ohci->vbus_reg);
> +
> return 1;
> }
>
> static int ohci_da8xx_get_oci(struct usb_hcd *hcd)
> {
> + struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
> struct device *dev = hcd->self.controller;
> struct da8xx_ohci_root_hub *hub = dev_get_platdata(dev);
> + unsigned int flags;
> + int ret;
>
> if (hub && hub->get_oci)
> return hub->get_oci(1);
>
> + if (!da8xx_ohci->vbus_reg)
> + return 0;
> +
> + ret = regulator_get_error_flags(da8xx_ohci->vbus_reg, &flags);
> + if (ret)
> + return ret;
> +
> + if (flags & REGULATOR_ERROR_OVER_CURRENT)
> + return 1;
> +
> return 0;
> }
>
> static int ohci_da8xx_has_set_power(struct usb_hcd *hcd)
> {
> + struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
> struct device *dev = hcd->self.controller;
> struct da8xx_ohci_root_hub *hub = dev_get_platdata(dev);
>
> if (hub && hub->set_power)
> return 1;
>
> + if (da8xx_ohci->vbus_reg)
> + return 1;
> +
> return 0;
> }
>
> static int ohci_da8xx_has_oci(struct usb_hcd *hcd)
> {
> + struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
> struct device *dev = hcd->self.controller;
> struct da8xx_ohci_root_hub *hub = dev_get_platdata(dev);
>
> if (hub && hub->get_oci)
> return 1;
>
> + if (da8xx_ohci->vbus_reg)
> + return 1;
> +
> return 0;
> }
>
> @@ -160,15 +212,41 @@ static void ohci_da8xx_ocic_handler(struct da8xx_ohci_root_hub *hub,
> hub->set_power(port, 0);
> }
>
> +static int ohci_da8xx_regulator_event(struct notifier_block *nb,
> + unsigned long event, void *data)
> +{
> + struct da8xx_ohci_hcd *da8xx_ohci =
> + container_of(nb, struct da8xx_ohci_hcd, nb);
> + struct device *dev = da8xx_ohci->hcd->self.controller;
> +
> + if (event & REGULATOR_EVENT_OVER_CURRENT) {
> + dev_warn(dev, "over current event\n");
> + ocic_mask |= 1;
Following up from a v5 thread that is still applicable here, Axel said:
> I did a couple of tests, and i don't get those prints do you get them?.
The problem here is that ocic_mask |= 1; is wrong. It needs to be...
ocic_mask |= (1 << 1);
If you look at the other uses of ocic_mask, you will see why this it
needs to be this way. Once you make this change, then you will see this
in the kernel log:
usb 1-1: USB disconnect, device number 2
usb 1-1: may be reset is needed?..
ohci ohci: over current event
usb usb1-port1: over-current condition
So, we don't need the dev_warn() here.
More from Axel:
> What i understand is that they happen when we get a hub event that is
> reporting the over current. Which is what the root hub of the davinci
system
> does not have, and why we use gpios instead).
Even though the hardware is not capable of detecting the overcurrent by
itself, we are poking the registers in ohci_da8xx_hub_control(), so the
core hub driver sees it just the same as if the hardware itself changed
the register.
> + ohci_da8xx_set_power(da8xx_ohci->hcd, 0);
> + }
> +
> + return 0;
> +}
> +
> static int ohci_da8xx_register_notify(struct usb_hcd *hcd)
> {
> + struct da8xx_ohci_hcd *da8xx_ohci = to_da8xx_ohci(hcd);
> struct device *dev = hcd->self.controller;
> struct da8xx_ohci_root_hub *hub = dev_get_platdata(dev);
> + int ret = 0;
> +
> + if (hub && hub->ocic_notify) {
> + ret = hub->ocic_notify(ohci_da8xx_ocic_handler);
> + } else if (da8xx_ohci->vbus_reg) {
> + da8xx_ohci->nb.notifier_call = ohci_da8xx_regulator_event;
> + ret = devm_regulator_register_notifier(da8xx_ohci->vbus_reg,
> + &da8xx_ohci->nb);
> + }
>
> - if (hub && hub->ocic_notify)
> - return hub->ocic_notify(ohci_da8xx_ocic_handler);
> + if (ret)
> + dev_err(dev, "Failed to register notifier: %d\n", ret);
>
> - return 0;
> + return ret;
> }
>
> static void ohci_da8xx_unregister_notify(struct usb_hcd *hcd)
> @@ -331,6 +409,7 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> da8xx_ohci = to_da8xx_ohci(hcd);
> + da8xx_ohci->hcd = hcd;
>
> da8xx_ohci->usb11_clk = devm_clk_get(&pdev->dev, "usb11");
> if (IS_ERR(da8xx_ohci->usb11_clk)) {
> @@ -348,6 +427,18 @@ static int ohci_da8xx_probe(struct platform_device *pdev)
> goto err;
> }
>
> + da8xx_ohci->vbus_reg = devm_regulator_get_optional(&pdev->dev, "vbus");
> + if (IS_ERR(da8xx_ohci->vbus_reg)) {
> + error = PTR_ERR(da8xx_ohci->vbus_reg);
> + if (error == -ENODEV) {
> + da8xx_ohci->vbus_reg = NULL;
> + } else {
It might be good to skip the dev_err() if we get -EPROBE_DEFER
> + dev_err(&pdev->dev,
> + "Failed to get regulator\n");
> + goto err;
> + }
> + }
> +
> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> hcd->regs = devm_ioremap_resource(&pdev->dev, mem);
> if (IS_ERR(hcd->regs)) {
>
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