/*
- * DB3 Platform driver for AP bridge control interface.
+ * DB3 Platform driver to enable Unipro link.
*
* Copyright 2014-2015 Google Inc.
* Copyright 2014-2015 Linaro Ltd.
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
+#include <linux/clk.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/regulator/consumer.h>
#include <linux/pinctrl/consumer.h>
-enum apb_state {
- APB_STATE_OFF,
- APB_STATE_ACTIVE,
- APB_STATE_STANDBY,
-};
-
-/*
- * Control GPIO signals to and from AP <=> AP Bridges
- */
-struct apb_ctrl_gpios {
- int wake_detect; /* bi-dir, maps to WAKE_MOD and WAKE_FRAME signals */
- int reset;
- int boot_ret;
- int pwroff;
- int wake_in;
- int wake_out;
- int pwrdn;
-};
-
-struct apb_ctrl_drvdata {
- struct apb_ctrl_gpios ctrl;
+struct db3_platform_drvdata {
+ /* Control GPIO signals to and from AP <=> SVC */
+ int svc_reset_gpio;
+ bool is_reset_act_hi;
+ int svc_sysboot_gpio;
- unsigned int wake_detect_irq;
- enum apb_state state;
-
- struct regulator *vcore;
- struct regulator *vio;
+ unsigned int svc_refclk_req;
+ struct clk *svc_ref_clk;
struct pinctrl *pinctrl;
struct pinctrl_state *pin_default;
- /* To protect concurrent access of GPIO registers, need protection */
- spinlock_t lock;
+ int num_apbs;
};
-static inline void assert_wake(unsigned int wake_detect)
-{
- gpio_set_value(wake_detect, 1);
-}
-
-static inline void deassert_wake(unsigned int wake_detect)
-{
- gpio_set_value(wake_detect, 0);
-}
-
-static irqreturn_t apb_ctrl_wake_detect_irq(int irq, void *devid)
+static inline void svc_reset_onoff(unsigned int gpio, bool onoff)
{
- struct apb_ctrl_drvdata *apb_data = 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.
- */
- if (!gpio_is_valid(apb_data->ctrl.wake_detect) &&
- !gpio_is_valid(apb_data->ctrl.reset))
- return IRQ_HANDLED; /* Should it be IRQ_NONE ?? */
-
- spin_lock_irqsave(&apb_data->lock, flags);
-
- if (apb_data->state != APB_STATE_ACTIVE) {
- /* Bring bridge out of reset on this event */
- gpio_set_value(apb_data->ctrl.reset, 0);
- apb_data->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_data->lock, flags);
-
- return IRQ_HANDLED;
+ gpio_set_value(gpio, onoff);
}
-static void apb_ctrl_cleanup(struct apb_ctrl_drvdata *apb_data)
+static void db3_platform_cleanup(struct db3_platform_drvdata *db3_pdata)
{
- if (apb_data->vcore && regulator_is_enabled(apb_data->vcore) > 0)
- regulator_disable(apb_data->vcore);
-
- if (apb_data->vio && regulator_is_enabled(apb_data->vio) > 0)
- regulator_disable(apb_data->vio);
-
/* As part of exit, put APB back in reset state */
- if (gpio_is_valid(apb_data->ctrl.reset))
- gpio_set_value(apb_data->ctrl.reset, 1);
-
- /* TODO: May have to send an event to SVC about this exit */
+ if (gpio_is_valid(db3_pdata->svc_reset_gpio))
+ svc_reset_onoff(db3_pdata->svc_reset_gpio,
+ db3_pdata->is_reset_act_hi);
}
-/*
- * Note: Please do not modify the below sequence, as it is as per the spec
- */
-static int apb_ctrl_init_seq(struct device *dev,
- struct apb_ctrl_drvdata *apb_data)
+static int db3_platform_probe(struct platform_device *pdev)
{
+ struct db3_platform_drvdata *db3_pdata;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
int ret;
- pinctrl_select_state(apb_data->pinctrl, apb_data->pin_default);
+ db3_pdata = devm_kzalloc(&pdev->dev, sizeof(*db3_pdata), GFP_KERNEL);
+ if (!db3_pdata)
+ return -ENOMEM;
- /* Hold APB in reset state */
- ret = devm_gpio_request_one(dev, apb_data->ctrl.reset,
- GPIOF_OUT_INIT_LOW, "reset");
- if (ret) {
- dev_err(dev, "Failed requesting reset gpio %d\n",
- apb_data->ctrl.reset);
+ /* setup svc reset gpio */
+ db3_pdata->is_reset_act_hi = of_property_read_bool(np, "svc,reset-active-high");
+ db3_pdata->svc_reset_gpio = of_get_named_gpio(np, "svc,reset-gpio", 0);
+ if (db3_pdata->svc_reset_gpio < 0) {
+ dev_err(dev, "failed to get reset-gpio\n");
+ ret = -ENODEV;
return ret;
}
-
- /* Enable power to APB */
- if (apb_data->vcore) {
- ret = regulator_enable(apb_data->vcore);
- if (ret) {
- dev_err(dev, "failed to enable core regulator\n");
- return ret;
- }
- }
-
- if (apb_data->vio) {
- ret = regulator_enable(apb_data->vio);
- if (ret) {
- dev_err(dev, "failed to enable IO regulator\n");
- return ret;
- }
- }
-
- /*
- * We should be safe here to deassert boot retention signal, as
- * we are only supporting cold boot as of now.
- */
- ret = devm_gpio_request_one(dev, apb_data->ctrl.boot_ret,
- GPIOF_OUT_INIT_LOW, "boot retention");
+ ret = devm_gpio_request(dev, db3_pdata->svc_reset_gpio, "svc-reset");
if (ret) {
- dev_err(dev, "Failed requesting reset gpio %d\n",
- apb_data->ctrl.boot_ret);
+ dev_err(dev, "failed to request svc-reset gpio:%d\n", ret);
return ret;
}
-
- ret = devm_gpio_request(dev, apb_data->ctrl.wake_detect, "wake detect");
- if (ret)
- dev_err(dev, "Failed requesting wake_detect gpio %d\n",
- apb_data->ctrl.wake_detect);
-
- return ret;
-}
-
-static int apb_ctrl_get_devtree_data(struct device *dev,
- struct apb_ctrl_drvdata *apb_data)
-{
- struct device_node *np = dev->of_node;
-
- /* fetch control signals */
- apb_data->ctrl.wake_detect = of_get_named_gpio(np, "wake-detect-gpios", 0);
- if (!gpio_is_valid(apb_data->ctrl.wake_detect)) {
- dev_err(dev, "failed to get wake detect gpio\n");
- return apb_data->ctrl.wake_detect;
- }
-
- apb_data->ctrl.reset = of_get_named_gpio(np, "reset-gpios", 0);
- if (!gpio_is_valid(apb_data->ctrl.reset)) {
- dev_err(dev, "failed to get reset gpio\n");
- return apb_data->ctrl.reset;
+ ret = gpio_direction_output(db3_pdata->svc_reset_gpio, db3_pdata->is_reset_act_hi);
+ if (ret) {
+ dev_err(dev, "failed to set svc-reset gpio dir:%d\n", ret);
+ return ret;
}
- apb_data->ctrl.boot_ret = of_get_named_gpio(np, "boot-ret-gpios", 0);
- if (!gpio_is_valid(apb_data->ctrl.boot_ret)) {
- dev_err(dev, "failed to get boot retention gpio\n");
- return apb_data->ctrl.boot_ret;
+ db3_pdata->svc_sysboot_gpio = of_get_named_gpio(np, "svc,sysboot-gpio", 0);
+ if (db3_pdata->svc_sysboot_gpio < 0) {
+ dev_err(dev, "failed to get sysboot gpio\n");
+ ret = -ENODEV;
+ return ret;
}
-
- /* It's not mandatory to support power management interface */
- apb_data->ctrl.pwroff = of_get_named_gpio(np, "pwr-off-gpios", 0);
- if (!gpio_is_valid(apb_data->ctrl.pwroff))
- dev_info(dev, "failed to get power off gpio\n");
-
- apb_data->ctrl.pwrdn = of_get_named_gpio(np, "pwr-down-gpios", 0);
- if (!gpio_is_valid(apb_data->ctrl.pwrdn))
- dev_info(dev, "failed to get power down gpio\n");
-
- /* Regulators are optional, as we may have fixed supply coming in */
- apb_data->vcore = devm_regulator_get(dev, "vcore");
- if (IS_ERR_OR_NULL(apb_data->vcore)) {
- dev_info(dev, "no core regulator found\n");
- apb_data->vcore = NULL;
+ ret = devm_gpio_request(dev, db3_pdata->svc_sysboot_gpio, "sysboot0");
+ if (ret) {
+ dev_err(dev, "failed to request sysboot0 gpio:%d\n", ret);
+ return ret;
}
-
- apb_data->vio = devm_regulator_get(dev, "vio");
- if (IS_ERR_OR_NULL(apb_data->vio)) {
- dev_info(dev, "no IO regulator found\n");
- apb_data->vio = NULL;
+ ret = gpio_direction_output(db3_pdata->svc_sysboot_gpio, 0);
+ if (ret) {
+ dev_err(dev, "failed to set svc-reset gpio dir:%d\n", ret);
+ return ret;
}
- apb_data->pinctrl = devm_pinctrl_get(dev);
- if (IS_ERR(apb_data->pinctrl)) {
- dev_err(dev, "could not get pinctrl handle\n");
- return PTR_ERR(apb_data->pinctrl);
+ /* setup the clock request gpio first */
+ db3_pdata->svc_refclk_req = of_get_named_gpio(np, "svc,refclk-req-gpio", 0);
+ if (db3_pdata->svc_refclk_req < 0) {
+ dev_err(dev, "failed to get svc clock-req gpio\n");
+ return -ENODEV;
}
- apb_data->pin_default = pinctrl_lookup_state(apb_data->pinctrl, "default");
- if (IS_ERR(apb_data->pin_default)) {
- dev_err(dev, "could not get default pin state\n");
- return PTR_ERR(apb_data->pin_default);
+ ret = devm_gpio_request(dev, db3_pdata->svc_refclk_req, "svc-clk-req");
+ if (ret) {
+ dev_err(dev, "failed to request svc-clk-req gpio: %d\n", ret);
+ return ret;
}
-
- return 0;
-}
-
-static int apb_ctrl_probe(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
- struct apb_ctrl_drvdata *apb_data;
- int ret;
-
- apb_data = devm_kzalloc(&pdev->dev, sizeof(*apb_data), GFP_KERNEL);
- if (!apb_data)
- return -ENOMEM;
-
- ret = apb_ctrl_get_devtree_data(dev, apb_data);
+ ret = gpio_direction_input(db3_pdata->svc_refclk_req);
if (ret) {
- dev_err(dev, "failed to get devicetree data %d\n", ret);
+ dev_err(dev, "failed to set svc-clk-req gpio dir :%d\n", ret);
return ret;
}
- ret = apb_ctrl_init_seq(dev, apb_data);
+ /* setup refclk2 to follow the pin */
+ db3_pdata->svc_ref_clk = devm_clk_get(dev, "svc_ref_clk");
+ if (IS_ERR(db3_pdata->svc_ref_clk)) {
+ ret = PTR_ERR(db3_pdata->svc_ref_clk);
+ dev_err(dev, "failed to get svc_ref_clk: %d\n", ret);
+ return ret;
+ }
+ ret = clk_prepare_enable(db3_pdata->svc_ref_clk);
if (ret) {
- dev_err(dev, "failed to set init state of control signal %d\n",
- ret);
- goto exit;
+ dev_err(dev, "failed to enable svc_ref_clk: %d\n", ret);
+ return ret;
}
- platform_set_drvdata(pdev, apb_data);
-
- apb_data->state = APB_STATE_OFF;
- /*
- * Assert AP module detect signal by pulling wake_detect low
- */
- deassert_wake(apb_data->ctrl.wake_detect);
+ platform_set_drvdata(pdev, db3_pdata);
- /*
- * In order to receive an interrupt, the GPIO must be set to input mode
- *
- * As per WDM spec, for the cold boot, the wake pulse must be
- * >= 5000 usec, but at this stage it is power up sequence,
- * so we always treat it as cold boot.
- */
- gpio_direction_input(apb_data->ctrl.wake_detect);
+ db3_pdata->num_apbs = of_get_child_count(np);
+ dev_dbg(dev, "Number of APB's available - %d\n", db3_pdata->num_apbs);
- ret = devm_request_irq(dev, gpio_to_irq(apb_data->ctrl.wake_detect),
- apb_ctrl_wake_detect_irq,
- IRQF_TRIGGER_RISING,
- "wake detect", apb_data);
- if (ret) {
- dev_err(&pdev->dev, "failed to request wake detect IRQ\n");
- goto exit;
- }
+ /* bring SVC out of reset */
+ svc_reset_onoff(db3_pdata->svc_reset_gpio, !db3_pdata->is_reset_act_hi);
- /*
- * Interrupt handling for WAKE_IN (from bridge) signal is required
- *
- * Assumption here is, AP already would have woken up and in the
- * WAKE_IN/WAKE_FRAME event from bridge, as AP would pass-through event
- * to SVC.
- *
- * Not sure anything else needs to take care here.
- */
- dev_info(dev, "Device registered successfully \n");
- return 0;
+ /* probe all childs here */
+ ret = of_platform_populate(np, NULL, NULL, dev);
+ if (ret)
+ dev_err(dev, "no child node found\n");
-exit:
- apb_ctrl_cleanup(apb_data);
+ dev_info(dev, "Device registered successfully\n");
return ret;
}
-static int apb_ctrl_remove(struct platform_device *pdev)
+static int db3_platform_remove(struct platform_device *pdev)
{
- struct apb_ctrl_drvdata *apb_data = platform_get_drvdata(pdev);
+ struct db3_platform_drvdata *db3_pdata = platform_get_drvdata(pdev);
- if (apb_data)
- apb_ctrl_cleanup(apb_data);
+ if (db3_pdata)
+ db3_platform_cleanup(db3_pdata);
platform_set_drvdata(pdev, NULL);
return 0;
}
-static int apb_ctrl_suspend(struct device *dev)
+static int db3_platform_suspend(struct device *dev)
{
/*
* If timing profile premits, we may shutdown bridge
return 0;
}
-static int apb_ctrl_resume(struct device *dev)
+static int db3_platform_resume(struct device *dev)
{
/*
* Atleast for ES2 we have to meet the delay requirement between
return 0;
}
-static SIMPLE_DEV_PM_OPS(apb_ctrl_pm_ops, apb_ctrl_suspend, apb_ctrl_resume);
+static SIMPLE_DEV_PM_OPS(db3_platform_pm_ops, db3_platform_suspend, db3_platform_resume);
-static struct of_device_id apb_ctrl_of_match[] = {
- { .compatible = "usbffff,2", },
+static struct of_device_id db3_platform_of_match[] = {
+ { .compatible = "google,db3-platform", }, /* Use PID/VID of SVC device */
{ },
};
-MODULE_DEVICE_TABLE(of, apb_ctrl_of_match);
+MODULE_DEVICE_TABLE(of, db3_platform_of_match);
-static struct platform_driver apb_ctrl_device_driver = {
- .probe = apb_ctrl_probe,
- .remove = apb_ctrl_remove,
+static struct platform_driver db3_platform_device_driver = {
+ .probe = db3_platform_probe,
+ .remove = db3_platform_remove,
.driver = {
- .name = "unipro-APbridge",
- .pm = &apb_ctrl_pm_ops,
- .of_match_table = of_match_ptr(apb_ctrl_of_match),
+ .name = "db3-platform-ctrl",
+ .pm = &db3_platform_pm_ops,
+ .of_match_table = of_match_ptr(db3_platform_of_match),
}
};
-module_platform_driver(apb_ctrl_device_driver);
+module_platform_driver(db3_platform_device_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vaibhav Hiremath <vaibhav.hiremath@linaro.org>");
-MODULE_DESCRIPTION("AP Bridge Control Driver for DB3 platform");
+MODULE_DESCRIPTION("DB3 Platform Driver");
projects / users / jedix / linux-maple.git / commitdiff