greybus: arche-apb-ctrl: Remove wake_detect gpio and related code

With TIME_SYNC functionality, assignment of wake/detect pin
will change,
  WD_8A => to bring APB's out of reset
  WD_8B => TIME_SYNC operation

So in order to support this, we can no longer keep wake_detect
gpio in apb-ctrl driver. So remove it.
In the subsequent patches, wake_detect support will be added
to parent SVC driver (arche-platform) who is responsible for SVC control.

Note that, this patch also removes ISR related code.
The APB state still is maintained, for future use.

Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Tested-by: Michael Scott <michael.scott@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

diff --git a/drivers/staging/greybus/arche-apb-ctrl.c b/drivers/staging/greybus/arche-apb-ctrl.c
index afdaeca999cab156cc361b8906a79c455717593b..5b9a3ed212af5524b6b54d23460ef8f194eca5c1 100644 (file)
--- a/drivers/staging/greybus/arche-apb-ctrl.c
+++ b/drivers/staging/greybus/arche-apb-ctrl.c
@@ -29,7 +29,6 @@ enum apb_state {
 
 struct arche_apb_ctrl_drvdata {
        /* Control GPIO signals to and from AP <=> AP Bridges */
-       int wake_detect_gpio; /* bi-dir,maps to WAKE_MOD & WAKE_FRAME signals */
        int resetn_gpio;
        int boot_ret_gpio;
        int pwroff_gpio;
@@ -37,7 +36,6 @@ struct arche_apb_ctrl_drvdata {
        int wake_out_gpio;
        int pwrdn_gpio;
 
-       unsigned int wake_detect_irq;
        enum apb_state state;
 
        struct regulator *vcore;
@@ -48,9 +46,6 @@ struct arche_apb_ctrl_drvdata {
 
        struct pinctrl *pinctrl;
        struct pinctrl_state *pin_default;
-
-       /* To protect concurrent access of GPIO registers, need protection */
-       spinlock_t lock;
 };
 
 /*
@@ -78,45 +73,6 @@ static void unexport_gpios(struct arche_apb_ctrl_drvdata *apb)
        gpio_unexport(apb->resetn_gpio);
 }
 
-static irqreturn_t apb_ctrl_wake_detect_irq(int irq, void *devid)
-{
-       struct arche_apb_ctrl_drvdata *apb = devid;
-       unsigned long flags;
-
-       /*
-        * TODO:
-        * Since currently SoC GPIOs are being used we are safe here
-        * But ideally we should create a workqueue and process the control
-        * signals, especially when we start using GPIOs over slow
-        * buses like I2C.
-        */
-       spin_lock_irqsave(&apb->lock, flags);
-
-       if (apb->state != APB_STATE_ACTIVE) {
-               /* Bring bridge out of reset on this event */
-               gpio_set_value(apb->resetn_gpio, 1);
-               apb->state = APB_STATE_ACTIVE;
-       } else {
-               /*
-                * Assert Wake_OUT signal to APB
-                * It would resemble WakeDetect module's signal pass-through
-                */
-               /*
-                * We have to generate the pulse, so we may need to schedule
-                * workqueue here.
-                *
-                * Also, since we are using both rising and falling edge for
-                * interrupt trigger, we may not need workqueue. Just pass
-                * through the value to bridge.
-                * Just read GPIO value and pass it to the bridge
-                */
-       }
-
-       spin_unlock_irqrestore(&apb->lock, flags);
-
-       return IRQ_HANDLED;
-}
-
 /*
  * Note: Please do not modify the below sequence, as it is as per the spec
  */
@@ -190,14 +146,6 @@ static int apb_ctrl_init_seq(struct platform_device *pdev,
        gpio_set_value(apb->boot_ret_gpio, 0);
        udelay(50);
 
-       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);
-               goto out_vio_disable;
-       }
-
        return 0;
 
 out_vio_disable:
@@ -216,12 +164,6 @@ static int apb_ctrl_get_devtree_data(struct platform_device *pdev,
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
 
-       apb->wake_detect_gpio = of_get_named_gpio(np, "wake-detect-gpios", 0);
-       if (apb->wake_detect_gpio < 0) {
-               dev_err(dev, "failed to get wake detect gpio\n");
-               return apb->wake_detect_gpio;
-       }
-
        apb->resetn_gpio = of_get_named_gpio(np, "reset-gpios", 0);
        if (apb->resetn_gpio < 0) {
                dev_err(dev, "failed to get reset gpio\n");
@@ -275,19 +217,15 @@ static int apb_ctrl_get_devtree_data(struct platform_device *pdev,
 
 static void apb_ctrl_cleanup(struct arche_apb_ctrl_drvdata *apb)
 {
-       unsigned long flags;
-
        if (!IS_ERR(apb->vcore) && regulator_is_enabled(apb->vcore) > 0)
                regulator_disable(apb->vcore);
 
        if (!IS_ERR(apb->vio) && regulator_is_enabled(apb->vio) > 0)
                regulator_disable(apb->vio);
 
-       spin_lock_irqsave(&apb->lock, flags);
        /* As part of exit, put APB back in reset state */
        gpio_set_value(apb->resetn_gpio, 0);
        apb->state = APB_STATE_OFF;
-       spin_unlock_irqrestore(&apb->lock, flags);
 
        /* TODO: May have to send an event to SVC about this exit */
 }
@@ -315,27 +253,8 @@ int arche_apb_ctrl_probe(struct platform_device *pdev)
                return ret;
        }
 
-       spin_lock_init(&apb->lock);
-
        apb->state = APB_STATE_OFF;
-       /*
-        * Assert AP module detect signal by pulling wake_detect low
-        */
-       assert_gpio(apb->wake_detect_gpio);
 
-       /*
-        * In order to receive an interrupt, the GPIO must be set to input mode
-        */
-       gpio_direction_input(apb->wake_detect_gpio);
-
-       ret = devm_request_irq(dev, gpio_to_irq(apb->wake_detect_gpio),
-                       apb_ctrl_wake_detect_irq, IRQF_TRIGGER_FALLING,
-                       "wake detect", apb);
-       if (ret) {
-               dev_err(dev, "failed to request wake detect IRQ\n");
-               apb_ctrl_cleanup(apb);
-               return ret;
-       }
 
        platform_set_drvdata(pdev, apb);