diff options
Diffstat (limited to 'drivers/soc/qcom/inrush-current-mitigation.c')
| -rw-r--r-- | drivers/soc/qcom/inrush-current-mitigation.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/soc/qcom/inrush-current-mitigation.c b/drivers/soc/qcom/inrush-current-mitigation.c new file mode 100644 index 000000000000..5f141fc9957f --- /dev/null +++ b/drivers/soc/qcom/inrush-current-mitigation.c @@ -0,0 +1,170 @@ +/* + * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/async.h> +#include <linux/clk/gdsc.h> +#include <linux/regulator/consumer.h> +#include <soc/qcom/subsystem_notif.h> + +struct subsystem { + const char *name; + void *notif_handle; + struct notifier_block nb; + bool booted; + struct inrush_driver_data *drv_data; +}; + +struct inrush_driver_data { + int subsys_count; + int subsys_boot_count; + struct regulator *vreg; + /* Must be the last member */ + struct subsystem *subsystems; +}; + +#define notifier_to_subsystem(d) container_of(d, struct subsystem, nb) + +static void free_resources(void *data, async_cookie_t cookie) +{ + struct inrush_driver_data *drv_data = data; + struct subsystem *subsys; + int i; + + gdsc_allow_clear_retention(drv_data->vreg); + devm_regulator_put(drv_data->vreg); + + for (i = 0; i < drv_data->subsys_count; i++) { + subsys = &drv_data->subsystems[i]; + subsys_notif_unregister_notifier(subsys->notif_handle, + &subsys->nb); + } + + kfree(drv_data); + pr_info("inrush-current-mitigation driver exited\n"); +} + +static int mitigate_inrush_notifier_cb(struct notifier_block *nb, + unsigned long code, void *ss_handle) +{ + struct subsystem *subsys = notifier_to_subsystem(nb); + struct inrush_driver_data *drv_data = subsys->drv_data; + + if (subsys->booted) + return NOTIFY_DONE; + + switch (code) { + case SUBSYS_AFTER_POWERUP: + pr_info("%s: subsystem %s has completed powerup\n", __func__, + subsys->name); + subsys->booted = true; + drv_data->subsys_boot_count++; + break; + default: + return NOTIFY_DONE; + } + + /* + * If all subsystems are up, job of this driver ends, lets + * free resources. + */ + if (drv_data->subsys_count == drv_data->subsys_boot_count) + async_schedule(free_resources, drv_data); + + return NOTIFY_DONE; +} + +static int mitigate_inrush_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + int i, retval; + struct subsystem *subsys; + struct inrush_driver_data *drv_data; + + retval = of_property_count_strings(np, + "qcom,dependent-subsystems"); + if (IS_ERR_VALUE(retval)) { + dev_err(dev, "Failed to get dependent subsystems\n"); + return -EINVAL; + } + + drv_data = kzalloc((retval * sizeof(struct subsystem) + + sizeof(struct inrush_driver_data)), GFP_KERNEL); + + if (!drv_data) + return -ENOMEM; + + drv_data->subsystems = (void *)drv_data + + sizeof(struct inrush_driver_data); + drv_data->subsys_count = retval; + + for (i = 0; i < drv_data->subsys_count; i++) { + subsys = &drv_data->subsystems[i]; + subsys->drv_data = drv_data; + of_property_read_string_index(np, "qcom,dependent-subsystems", + i, &subsys->name); + subsys->nb.notifier_call = mitigate_inrush_notifier_cb; + subsys->notif_handle = + subsys_notif_register_notifier(subsys->name, + &subsys->nb); + if (IS_ERR(subsys->notif_handle)) { + dev_err(dev, "Notifier registration failed for %s\n", + subsys->name); + retval = PTR_ERR(subsys->notif_handle); + goto err_subsys_notif; + } + } + + drv_data->vreg = devm_regulator_get(dev, "vdd"); + if (IS_ERR(drv_data->vreg)) { + dev_err(dev, "Failed to get regulator\n"); + return PTR_ERR(drv_data->vreg); + } + + return 0; + +err_subsys_notif: + for (i = 0; i < drv_data->subsys_count; i++) { + subsys = &drv_data->subsystems[i]; + subsys_notif_unregister_notifier(subsys->notif_handle, + &subsys->nb); + } + kfree(drv_data); + return retval; +} + +static const struct of_device_id mitigate_inrush_match_table[] = { + { .compatible = "qcom,msm-inrush-current-mitigation" }, + {}, +}; + +static struct platform_driver mitigate_inrush_driver = { + .probe = mitigate_inrush_probe, + .driver = { + .name = "msm-inrush-current", + .owner = THIS_MODULE, + .of_match_table = mitigate_inrush_match_table, + }, +}; + +static int init_msm_mitigate_inrush(void) +{ + return platform_driver_register(&mitigate_inrush_driver); +} +late_initcall(init_msm_mitigate_inrush); |