Messages in this thread | | | Date | Thu, 29 Aug 2013 19:15:02 +0530 | From | George Cherian <> | Subject | Re: [PATCH v3 1/3] extcon: extcon-gpio-usbvid: Generic USB VBUS/ID detection via GPIO |
| |
Hi Chanwoo,
On 8/29/2013 5:42 PM, Chanwoo Choi wrote: [big snip ] >>> I tested various development board based on Samsung Exynos series SoC. >>> Although some gpio of Exynos series SoC set high state(non zero, 1) as default value, >>> this gpio state could mean off state, disconnected or un-powered state according to gpio. >>> Of course, above explanation about specific gpio don't include all gpios. >>> This is meaning that there is possibility. >> okay then how about adding a flag for inverted logic too. something like this >> >> if(of_property_read_bool(np,"inverted_gpio)) >> gpio_usbvid->gpio_inv = 1; >> And always check on this before deciding? Is this fine ? >> >>>>> Second, >>>>> gpio_usbvid_set_initial_state() dertermine both "USB-HOST" and "USB" cable state at same time >>>>> in 'case ID_DETCT' according to 'gpio_usbvid->id_gpio'. But, I think that other extcon devices >>>>> would not control both "USB-HOST" and "USB" cable state at same time. >>>>> >>>>> Other extcon devices would support either "USB-HOST" or "USB" cable. >>>> The driver has 2 configurations. >>>> 1) supports implementations with both VBUS and ID pin are routed via gpio's for swicthing roles(compatible gpio-usb-vid). >>> As you explained about case 1, it is only used on dra7x SoC. >> No gpio-usb-id is used in dra7xx. dra7xx has got only ID pin routed via gpio. >>> Other SoC could not wish to control both "USB-HOST" and "USB" cable at same time. I could'nt actually parse this. You meant since the id_irq_handler handles both USB and USB-HOST cable its not proper? > I need your answer about above my opinion for other SoC. So how about this, I have removed the dra7x specific stuffs (gpio-usb-id)
static void gpio_usbvid_set_initial_state(struct gpio_usbvid *gpio_usbvid) { int id_current, vbus_current;
id_current = gpio_get_value_cansleep(gpio_usbvid->id_gpio); if (!!id_current == ID_FLOAT) extcon_set_cable_state(&gpio_usbvid->edev, "USB-HOST", false); else extcon_set_cable_state(&gpio_usbvid->edev, "USB-HOST", true);
vbus_current = gpio_get_value_cansleep(gpio_usbvid->vbus_gpio); if (!!vbus_current == VBUS_ON) extcon_set_cable_state(&gpio_usbvid->edev, "USB", true); else extcon_set_cable_state(&gpio_usbvid->edev, "USB", false); }
and the irq handlers like this
static irqreturn_t id_irq_handler(int irq, void *data) { struct gpio_usbvid *gpio_usbvid = (struct gpio_usbvid *)data; int id_current;
id_current = gpio_get_value_cansleep(gpio_usbvid->id_gpio); if (id_current == ID_GND) extcon_set_cable_state(&gpio_usbvid->edev, "USB-HOST", true); else extcon_set_cable_state(&gpio_usbvid->edev, "USB-HOST", false); return IRQ_HANDLED; }
static irqreturn_t vbus_irq_handler(int irq, void *data) { struct gpio_usbvid *gpio_usbvid = (struct gpio_usbvid *)data; int vbus_current;
vbus_current = gpio_get_value_cansleep(gpio_usbvid->vbus_gpio); if (vbus_current == VBUS_OFF) extcon_set_cable_state(&gpio_usbvid->edev, "USB", false); else extcon_set_cable_state(&gpio_usbvid->edev, "USB", true);
return IRQ_HANDLED; } [snip] >>> I have some confusion. I need additional your explanation. >>> Could this driver register only one interrupt handler either id_irq_handler() or vbus_irq_handler()? >> If compatible == ID_DETECT, only one handler --> id_irq_handler() and it will handle both USB and USB-HOST >>> or >>> Could this driver register two interrupt handler both id_irq_handler() or vbus_irq_handler()? >> If compatible == VBUS_ID_DETECT, 2 handlers --> id_irq_handler() will handle USB-HOST and vbus_irq_handler will handle USB. > As you mentioned, we cannot only control either USB or USB-HOST cable on this extcon driver. > This extcon driver is only suitable dra7x SoC. Do you still feel its dra7x specific if i modify it as above? > Because id_irq_handler() control both "USB-HOST" and "USB" cable at same time, > you need this setting order between "USB-HOST" and "USB" cable. >> yes > I think that the setting order between cables isn't general. It is specific method for dra7x SoC. So if i remove that part then? >>> Did you think that SoC should always connect either "USB-HOST" cable or "USB" cable? >> No, even if a physical cable is not connected it should default to either USB-HOST or USB > It isn't general. > > If physical cable isn't connected to extcon device, the state both USB-HOST and USB cable > should certainly be zero. Because The extcon consumer driver could set proper operation > according to cable state. okay > >> >>> I don't know this case except for dra7x SoC. So, I think it has dependency on specific SoC. > I need your answer about above my opinion. Hope i could answer you :-) >>> and can't agree as generic extcon gpio driver. >
-- -George
| |