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