From ae0bf3a62805fa80c8277dd293d9d9d9b8b4c7c0 Mon Sep 17 00:00:00 2001 From: Vaibhav Hiremath <vaibhav.hiremath@linaro.org> Date: Wed, 6 Jan 2016 23:46:45 +0530 Subject: [PATCH] greybus: arche-apb-ctrl: Set wake_detect gpio to low initially This patch enables handshaking of AP and SVC using wake_detect gpio (WD_8A and WD_8B). Note that WAKE_DETECT polarity is active-high, so in order to enable handshaking between AP <=> SVC, we need to set wake_detect gpio to low initially, so that driver can send WAKE_DET signal (active-high) to SVC and then SVC can send back WAKE_MOD signal (active-low). And on reception of WAKE_MOD signal, driver would bring respective APB out of reset. WD_8A => APB1 WD_8B => APB2 Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@google.com> --- drivers/staging/greybus/arche-apb-ctrl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/greybus/arche-apb-ctrl.c b/drivers/staging/greybus/arche-apb-ctrl.c index 8046e1eced83..d3db7fbb33b4 100644 --- a/drivers/staging/greybus/arche-apb-ctrl.c +++ b/drivers/staging/greybus/arche-apb-ctrl.c @@ -195,7 +195,8 @@ static int apb_ctrl_init_seq(struct platform_device *pdev, gpio_set_value(apb->boot_ret_gpio, 0); udelay(50); - ret = devm_gpio_request(dev, apb->wake_detect_gpio, "wake detect"); + ret = devm_gpio_request_one(dev, apb->wake_detect_gpio, + GPIOF_INIT_LOW, "wake detect"); if (ret) dev_err(dev, "Failed requesting wake_detect gpio %d\n", apb->wake_detect_gpio); -- 2.30.9