On 10/4/24 5:02 AM, Abbarapu, Venkatesh wrote:
Hi Marek,
-----Original Message----- From: Marek Vasut marex@denx.de Sent: Thursday, October 3, 2024 10:35 PM To: Abbarapu, Venkatesh venkatesh.abbarapu@amd.com; u-boot@lists.denx.de Cc: Simek, Michal michal.simek@amd.com; fabrice.gasnier@foss.st.com; git (AMD-Xilinx) git@amd.com Subject: Re: [PATCH v3 1/7] usb: onboard-hub: Add reset-gpio support
On 10/3/24 4:54 PM, Abbarapu, Venkatesh wrote:
Hi Marek,
-----Original Message----- From: Marek Vasut marex@denx.de Sent: Thursday, October 3, 2024 5:38 PM To: Abbarapu, Venkatesh venkatesh.abbarapu@amd.com; u-boot@lists.denx.de Cc: Simek, Michal michal.simek@amd.com; fabrice.gasnier@foss.st.com; git (AMD-Xilinx) git@amd.com Subject: Re: [PATCH v3 1/7] usb: onboard-hub: Add reset-gpio support
On 10/3/24 6:40 AM, Abbarapu, Venkatesh wrote:
Hi Marek,
Hi,
> @@ -30,7 +40,24 @@ static int usb_onboard_hub_probe(struct udevice
*dev)
> if (ret) > dev_err(dev, "can't enable vdd-supply: %d\n", ret); > > - return ret; > + hub->reset_gpio = devm_gpiod_get_optional(dev, "reset", > + GPIOD_IS_OUT | GPIOD_ACTIVE_LOW); > + /* property is optional, don't return error! */ > + if (hub->reset_gpio) {
if (!hub->reset_gpio) return 0;
<Venkatesh> As reset_gpio is optional property, by returning 0 the i2c sequence
wont be executed. The code in if (hub->reset_gpio) { ... } only toggles the GPIO reset ?
<Venkatesh> Yes...if(hub->reset_gpio) only toggles the GPIO reset.
So you can return 0 if reset_gpio is NULL and exit early . What's the problem ?
<Venkatesh> if reset_gpio is NULL by returning 0 we miss the below code which does i2c initialization sequence. Need to toggle the gpio and then does the i2c sequence if the reset_gpio is present, else we do the i2c initialization sequence.
Please show me the i2c sequence that is missed in this patch hunk:
+ if (hub->reset_gpio) { + ret = dm_gpio_set_value(hub->reset_gpio, 1); + if (ret) + return ret; + + udelay(data->reset_us); + + ret = dm_gpio_set_value(hub->reset_gpio, 0); + if (ret) + return ret; + + udelay(data->power_on_delay_us); + } + + return 0;