345 lines
9.5 KiB
C
345 lines
9.5 KiB
C
/*
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* Arche Platform driver to enable Unipro link.
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*
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* Copyright 2014-2015 Google Inc.
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* Copyright 2014-2015 Linaro Ltd.
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*
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* Released under the GPLv2 only.
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*/
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/gpio.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/of_gpio.h>
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#include <linux/of_platform.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include "arche_platform.h"
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struct arche_platform_drvdata {
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/* Control GPIO signals to and from AP <=> SVC */
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int svc_reset_gpio;
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bool is_reset_act_hi;
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int svc_sysboot_gpio;
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int wake_detect_gpio; /* bi-dir,maps to WAKE_MOD & WAKE_FRAME signals */
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unsigned int svc_refclk_req;
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struct clk *svc_ref_clk;
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struct pinctrl *pinctrl;
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struct pinctrl_state *pin_default;
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int num_apbs;
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struct delayed_work delayed_work;
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struct device *dev;
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};
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static inline void svc_reset_onoff(unsigned int gpio, bool onoff)
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{
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gpio_set_value(gpio, onoff);
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}
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/**
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* svc_delayed_work - Time to give SVC to boot.
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*/
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static void svc_delayed_work(struct work_struct *work)
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{
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struct arche_platform_drvdata *arche_pdata =
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container_of(work, struct arche_platform_drvdata, delayed_work.work);
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struct device *dev = arche_pdata->dev;
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struct device_node *np = dev->of_node;
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int timeout = 10;
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int ret;
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/*
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* 1. SVC and AP boot independently, with AP<-->SVC wake/detect pin
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* deasserted (LOW in this case)
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* 2.1. SVC allows 360 milliseconds to elapse after switch boots to work
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* around bug described in ENG-330.
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* 2.2. AP asserts wake/detect pin (HIGH) (this can proceed in parallel with 2.1)
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* 3. SVC detects assertion of wake/detect pin, and sends "wake out" signal to AP
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* 4. AP receives "wake out" signal, takes AP Bridges through their power
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* on reset sequence as defined in the bridge ASIC reference manuals
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* 5. AP takes USB3613 through its power on reset sequence
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* 6. AP enumerates AP Bridges
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*/
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gpio_set_value(arche_pdata->wake_detect_gpio, 1);
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gpio_direction_input(arche_pdata->wake_detect_gpio);
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do {
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/* Read the wake_detect GPIO, for WAKE_OUT event from SVC */
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if (gpio_get_value(arche_pdata->wake_detect_gpio) == 0)
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break;
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msleep(500);
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} while(timeout--);
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if (timeout >= 0) {
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ret = of_platform_populate(np, NULL, NULL, dev);
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if (!ret)
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/* Should we set wake_detect gpio to output again? */
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return;
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}
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/* FIXME: We may want to limit retries here */
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gpio_direction_output(arche_pdata->wake_detect_gpio, 0);
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schedule_delayed_work(&arche_pdata->delayed_work, msecs_to_jiffies(2000));
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}
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/* Export gpio's to user space */
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static void export_gpios(struct arche_platform_drvdata *arche_pdata)
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{
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gpio_export(arche_pdata->svc_reset_gpio, false);
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gpio_export(arche_pdata->svc_sysboot_gpio, false);
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}
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static void unexport_gpios(struct arche_platform_drvdata *arche_pdata)
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{
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gpio_unexport(arche_pdata->svc_reset_gpio);
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gpio_unexport(arche_pdata->svc_sysboot_gpio);
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}
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static void arche_platform_cleanup(struct arche_platform_drvdata *arche_pdata)
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{
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clk_disable_unprepare(arche_pdata->svc_ref_clk);
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/* As part of exit, put APB back in reset state */
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svc_reset_onoff(arche_pdata->svc_reset_gpio,
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arche_pdata->is_reset_act_hi);
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}
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static int arche_platform_probe(struct platform_device *pdev)
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{
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struct arche_platform_drvdata *arche_pdata;
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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int ret;
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arche_pdata = devm_kzalloc(&pdev->dev, sizeof(*arche_pdata), GFP_KERNEL);
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if (!arche_pdata)
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return -ENOMEM;
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/* setup svc reset gpio */
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arche_pdata->is_reset_act_hi = of_property_read_bool(np,
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"svc,reset-active-high");
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arche_pdata->svc_reset_gpio = of_get_named_gpio(np, "svc,reset-gpio", 0);
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if (arche_pdata->svc_reset_gpio < 0) {
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dev_err(dev, "failed to get reset-gpio\n");
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return arche_pdata->svc_reset_gpio;
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}
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ret = devm_gpio_request(dev, arche_pdata->svc_reset_gpio, "svc-reset");
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if (ret) {
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dev_err(dev, "failed to request svc-reset gpio:%d\n", ret);
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return ret;
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}
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ret = gpio_direction_output(arche_pdata->svc_reset_gpio,
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arche_pdata->is_reset_act_hi);
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if (ret) {
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dev_err(dev, "failed to set svc-reset gpio dir:%d\n", ret);
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return ret;
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}
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arche_pdata->svc_sysboot_gpio = of_get_named_gpio(np,
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"svc,sysboot-gpio", 0);
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if (arche_pdata->svc_sysboot_gpio < 0) {
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dev_err(dev, "failed to get sysboot gpio\n");
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return arche_pdata->svc_sysboot_gpio;
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}
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ret = devm_gpio_request(dev, arche_pdata->svc_sysboot_gpio, "sysboot0");
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if (ret) {
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dev_err(dev, "failed to request sysboot0 gpio:%d\n", ret);
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return ret;
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}
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ret = gpio_direction_output(arche_pdata->svc_sysboot_gpio, 0);
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if (ret) {
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dev_err(dev, "failed to set svc-reset gpio dir:%d\n", ret);
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return ret;
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}
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/* setup the clock request gpio first */
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arche_pdata->svc_refclk_req = of_get_named_gpio(np,
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"svc,refclk-req-gpio", 0);
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if (arche_pdata->svc_refclk_req < 0) {
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dev_err(dev, "failed to get svc clock-req gpio\n");
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return arche_pdata->svc_refclk_req;
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}
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ret = devm_gpio_request(dev, arche_pdata->svc_refclk_req, "svc-clk-req");
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if (ret) {
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dev_err(dev, "failed to request svc-clk-req gpio: %d\n", ret);
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return ret;
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}
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ret = gpio_direction_input(arche_pdata->svc_refclk_req);
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if (ret) {
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dev_err(dev, "failed to set svc-clk-req gpio dir :%d\n", ret);
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return ret;
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}
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/* setup refclk2 to follow the pin */
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arche_pdata->svc_ref_clk = devm_clk_get(dev, "svc_ref_clk");
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if (IS_ERR(arche_pdata->svc_ref_clk)) {
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ret = PTR_ERR(arche_pdata->svc_ref_clk);
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dev_err(dev, "failed to get svc_ref_clk: %d\n", ret);
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return ret;
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}
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ret = clk_prepare_enable(arche_pdata->svc_ref_clk);
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if (ret) {
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dev_err(dev, "failed to enable svc_ref_clk: %d\n", ret);
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return ret;
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}
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platform_set_drvdata(pdev, arche_pdata);
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/* bring SVC out of reset */
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svc_reset_onoff(arche_pdata->svc_reset_gpio,
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!arche_pdata->is_reset_act_hi);
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arche_pdata->num_apbs = of_get_child_count(np);
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dev_dbg(dev, "Number of APB's available - %d\n", arche_pdata->num_apbs);
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arche_pdata->wake_detect_gpio = of_get_named_gpio(np, "svc,wake-detect-gpio", 0);
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if (arche_pdata->wake_detect_gpio < 0) {
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dev_err(dev, "failed to get wake detect gpio\n");
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ret = arche_pdata->wake_detect_gpio;
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goto exit;
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}
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ret = devm_gpio_request(dev, arche_pdata->wake_detect_gpio, "wake detect");
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if (ret) {
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dev_err(dev, "Failed requesting wake_detect gpio %d\n",
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arche_pdata->wake_detect_gpio);
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goto exit;
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}
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arche_pdata->dev = &pdev->dev;
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INIT_DELAYED_WORK(&arche_pdata->delayed_work, svc_delayed_work);
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schedule_delayed_work(&arche_pdata->delayed_work, msecs_to_jiffies(2000));
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export_gpios(arche_pdata);
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dev_info(dev, "Device registered successfully\n");
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return 0;
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exit:
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arche_platform_cleanup(arche_pdata);
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return ret;
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}
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static int arche_remove_child(struct device *dev, void *unused)
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{
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struct platform_device *pdev = to_platform_device(dev);
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platform_device_unregister(pdev);
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return 0;
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}
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static int arche_platform_remove(struct platform_device *pdev)
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{
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struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
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device_for_each_child(&pdev->dev, NULL, arche_remove_child);
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arche_platform_cleanup(arche_pdata);
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platform_set_drvdata(pdev, NULL);
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unexport_gpios(arche_pdata);
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return 0;
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}
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static int arche_platform_suspend(struct device *dev)
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{
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/*
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* If timing profile premits, we may shutdown bridge
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* completely
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*
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* TODO: sequence ??
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*
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* Also, need to make sure we meet precondition for unipro suspend
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* Precondition: Definition ???
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*/
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return 0;
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}
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static int arche_platform_resume(struct device *dev)
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{
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/*
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* Atleast for ES2 we have to meet the delay requirement between
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* unipro switch and AP bridge init, depending on whether bridge is in
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* OFF state or standby state.
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*
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* Based on whether bridge is in standby or OFF state we may have to
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* assert multiple signals. Please refer to WDM spec, for more info.
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*
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*/
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(arche_platform_pm_ops,
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arche_platform_suspend,
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arche_platform_resume);
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static struct of_device_id arche_platform_of_match[] = {
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{ .compatible = "google,arche-platform", }, /* Use PID/VID of SVC device */
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{ },
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};
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static struct of_device_id arche_apb_ctrl_of_match[] = {
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{ .compatible = "usbffff,2", },
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{ },
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};
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static struct of_device_id arche_combined_id[] = {
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{ .compatible = "google,arche-platform", }, /* Use PID/VID of SVC device */
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{ .compatible = "usbffff,2", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, arche_combined_id);
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static struct platform_driver arche_platform_device_driver = {
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.probe = arche_platform_probe,
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.remove = arche_platform_remove,
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.driver = {
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.name = "arche-platform-ctrl",
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.pm = &arche_platform_pm_ops,
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.of_match_table = arche_platform_of_match,
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}
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};
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static struct platform_driver arche_apb_ctrl_device_driver = {
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.probe = arche_apb_ctrl_probe,
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.remove = arche_apb_ctrl_remove,
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.driver = {
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.name = "arche-apb-ctrl",
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.pm = &arche_apb_ctrl_pm_ops,
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.of_match_table = arche_apb_ctrl_of_match,
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}
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};
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static int __init arche_init(void)
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{
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int retval;
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retval = platform_driver_register(&arche_platform_device_driver);
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if (retval)
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return retval;
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retval = platform_driver_register(&arche_apb_ctrl_device_driver);
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if (retval)
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platform_driver_unregister(&arche_platform_device_driver);
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return retval;
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}
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module_init(arche_init);
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static void __exit arche_exit(void)
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{
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platform_driver_unregister(&arche_apb_ctrl_device_driver);
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platform_driver_unregister(&arche_platform_device_driver);
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}
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module_exit(arche_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Vaibhav Hiremath <vaibhav.hiremath@linaro.org>");
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MODULE_DESCRIPTION("Arche Platform Driver");
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