drivers/esoc/esoc-mdm-drv.c - kernel/msm-4.19 - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2013-2015, 2017-2018, The Linux Foundation. All rights reserved.
  */

 #include <linux/delay.h>
 #include <linux/workqueue.h>
 #include <linux/reboot.h>
 #include <linux/of.h>
 #include <linux/esoc_client.h>
 #include "esoc.h"
 #include "esoc-mdm.h"
 #include "mdm-dbg.h"

 /* Default number of powerup trial requests per session */
 #define ESOC_DEF_PON_REQ	2
 static unsigned int n_pon_tries = ESOC_DEF_PON_REQ;
 module_param(n_pon_tries, uint, 0644);
 MODULE_PARM_DESC(n_pon_tries,
 "Number of power-on retrials allowed upon boot failure");

 enum esoc_boot_fail_action {
 	BOOT_FAIL_ACTION_RETRY,
 	BOOT_FAIL_ACTION_COLD_RESET,
 	BOOT_FAIL_ACTION_SHUTDOWN,
 	BOOT_FAIL_ACTION_PANIC,
 	BOOT_FAIL_ACTION_NOP,
 };

 static unsigned int boot_fail_action = BOOT_FAIL_ACTION_NOP;
 module_param(boot_fail_action, uint, 0644);
 MODULE_PARM_DESC(boot_fail_action,
 "Actions: 0:Retry PON; 1:Cold reset; 2:Power-down; 3:APQ Panic; 4:No action");

 enum esoc_pon_state {
 	PON_INIT,
 	PON_SUCCESS,
 	PON_RETRY,
 	PON_FAIL
 };

 enum {
 	 PWR_OFF = 0x1,
 	 PWR_ON,
 	 BOOT,
 	 RUN,
 	 CRASH,
 	 IN_DEBUG,
 	 SHUTDOWN,
 	 RESET,
 	 PEER_CRASH,
 };

 struct mdm_drv {
 	unsigned int mode;
 	struct esoc_eng cmd_eng;
 	struct completion pon_done;
 	struct completion req_eng_wait;
 	struct esoc_clink *esoc_clink;
 	enum esoc_pon_state pon_state;
 	struct workqueue_struct *mdm_queue;
 	struct work_struct ssr_work;
 	struct notifier_block esoc_restart;
 };
 #define to_mdm_drv(d)	container_of(d, struct mdm_drv, cmd_eng)

 static int esoc_msm_restart_handler(struct notifier_block *nb,
 		unsigned long action, void *data)
 {
 	struct mdm_drv *mdm_drv = container_of(nb, struct mdm_drv,
 					esoc_restart);
 	struct esoc_clink *esoc_clink = mdm_drv->esoc_clink;
 	const struct esoc_clink_ops *const clink_ops = esoc_clink->clink_ops;

 	if (action == SYS_RESTART) {
 		if (mdm_dbg_stall_notify(ESOC_PRIMARY_REBOOT))
 			return NOTIFY_OK;
 		esoc_mdm_log(
 			"Reboot notifier: Notifying esoc of cold reboot\n");
 		dev_dbg(&esoc_clink->dev, "Notifying esoc of cold reboot\n");
 		clink_ops->notify(ESOC_PRIMARY_REBOOT, esoc_clink);
 	}
 	return NOTIFY_OK;
 }
 static void mdm_handle_clink_evt(enum esoc_evt evt,
 					struct esoc_eng *eng)
 {
 	struct mdm_drv *mdm_drv = to_mdm_drv(eng);
 	bool unexpected_state = false;

 	switch (evt) {
 	case ESOC_INVALID_STATE:
 		esoc_mdm_log(
 		"ESOC_INVALID_STATE: Calling complete with state: PON_FAIL\n");
 		mdm_drv->pon_state = PON_FAIL;
 		complete(&mdm_drv->pon_done);
 		break;
 	case ESOC_RUN_STATE:
 		esoc_mdm_log(
 		"ESOC_RUN_STATE: Calling complete with state: PON_SUCCESS\n");
 		mdm_drv->pon_state = PON_SUCCESS;
 		mdm_drv->mode = RUN,
 		complete(&mdm_drv->pon_done);
 		break;
 	case ESOC_RETRY_PON_EVT:
 		esoc_mdm_log(
 		"ESOC_RETRY_PON_EVT: Calling complete with state: PON_RETRY\n");
 		mdm_drv->pon_state = PON_RETRY;
 		complete(&mdm_drv->pon_done);
 		break;
 	case ESOC_UNEXPECTED_RESET:
 		esoc_mdm_log("evt_state: ESOC_UNEXPECTED_RESET\n");
 		unexpected_state = true;
 	case ESOC_ERR_FATAL:
 		if (!unexpected_state)
 			esoc_mdm_log("evt_state: ESOC_ERR_FATAL\n");

 		/*
 		 * Modem can crash while we are waiting for pon_done during
 		 * a subsystem_get(). Setting mode to CRASH will prevent a
 		 * subsequent subsystem_get() from entering poweron ops. Avoid
 		 * this by seting mode to CRASH only if device was up and
 		 * running.
 		 */
 		if (mdm_drv->mode == CRASH)
 			esoc_mdm_log(
 			"Modem in crash state already. Ignoring.\n");
 		if (mdm_drv->mode != RUN)
 			esoc_mdm_log("Modem not up. Ignoring.\n");
 		if (mdm_drv->mode == CRASH || mdm_drv->mode != RUN)
 			return;
 		mdm_drv->mode = CRASH;
 		queue_work(mdm_drv->mdm_queue, &mdm_drv->ssr_work);
 		break;
 	case ESOC_REQ_ENG_ON:
 		esoc_mdm_log(
 		"evt_state: ESOC_REQ_ENG_ON; Registered a req engine\n");
 		complete(&mdm_drv->req_eng_wait);
 		break;
 	default:
 		break;
 	}
 }

 static void mdm_ssr_fn(struct work_struct *work)
 {
 	struct mdm_drv *mdm_drv = container_of(work, struct mdm_drv, ssr_work);
 	struct mdm_ctrl *mdm = get_esoc_clink_data(mdm_drv->esoc_clink);

 	mdm_wait_for_status_low(mdm, false);

 	esoc_mdm_log("Starting SSR work\n");

 	/*
 	 * If restarting esoc fails, the SSR framework triggers a kernel panic
 	 */
 	esoc_clink_request_ssr(mdm_drv->esoc_clink);
 }

 static void esoc_client_link_power_on(struct esoc_clink *esoc_clink,
 							bool mdm_crashed)
 {
 	int i;
 	struct esoc_client_hook *client_hook;

 	dev_dbg(&esoc_clink->dev, "Calling power_on hooks\n");
 	esoc_mdm_log(
 	"Calling power_on hooks with crash state: %d\n", mdm_crashed);

 	for (i = 0; i < ESOC_MAX_HOOKS; i++) {
 		client_hook = esoc_clink->client_hook[i];
 		if (client_hook && client_hook->esoc_link_power_on)
 			client_hook->esoc_link_power_on(client_hook->priv,
 							mdm_crashed);
 	}
 }

 static void esoc_client_link_power_off(struct esoc_clink *esoc_clink,
 							bool mdm_crashed)
 {
 	int i;
 	struct esoc_client_hook *client_hook;

 	dev_dbg(&esoc_clink->dev, "Calling power_off hooks\n");
 	esoc_mdm_log(
 	"Calling power_off hooks with crash state: %d\n", mdm_crashed);

 	for (i = 0; i < ESOC_MAX_HOOKS; i++) {
 		client_hook = esoc_clink->client_hook[i];
 		if (client_hook && client_hook->esoc_link_power_off) {
 			client_hook->esoc_link_power_off(client_hook->priv,
 							mdm_crashed);
 		}
 	}
 }

 static void mdm_crash_shutdown(const struct subsys_desc *mdm_subsys)
 {
 	struct esoc_clink *esoc_clink =
 					container_of(mdm_subsys,
 							struct esoc_clink,
 								subsys);
 	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;

 	esoc_mdm_log("MDM crashed notification from SSR\n");

 	if (mdm_dbg_stall_notify(ESOC_PRIMARY_CRASH))
 		return;
 	clink_ops->notify(ESOC_PRIMARY_CRASH, esoc_clink);
 }

 static int mdm_subsys_shutdown(const struct subsys_desc *crashed_subsys,
 							bool force_stop)
 {
 	int ret;
 	struct esoc_clink *esoc_clink =
 	 container_of(crashed_subsys, struct esoc_clink, subsys);
 	struct mdm_drv *mdm_drv = esoc_get_drv_data(esoc_clink);
 	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;

 	esoc_mdm_log("Shutdown request from SSR\n");

 	if (mdm_drv->mode == CRASH || mdm_drv->mode == PEER_CRASH) {
 		esoc_mdm_log("Shutdown in crash mode\n");
 		if (mdm_dbg_stall_cmd(ESOC_PREPARE_DEBUG))
 			/* We want to mask debug command.
 			 * In this case return success
 			 * to move to next stage
 			 */
 			return 0;

 		esoc_clink_queue_request(ESOC_REQ_CRASH_SHUTDOWN, esoc_clink);
 		esoc_client_link_power_off(esoc_clink, true);

 		esoc_mdm_log("Executing the ESOC_PREPARE_DEBUG command\n");
 		ret = clink_ops->cmd_exe(ESOC_PREPARE_DEBUG,
 							esoc_clink);
 		if (ret) {
 			esoc_mdm_log("ESOC_PREPARE_DEBUG command failed\n");
 			dev_err(&esoc_clink->dev, "failed to enter debug\n");
 			return ret;
 		}
 		mdm_drv->mode = IN_DEBUG;
 	} else if (!force_stop) {
 		esoc_mdm_log("Graceful shutdown mode\n");
 		if (esoc_clink->subsys.sysmon_shutdown_ret) {
 			esoc_mdm_log(
 			"Executing the ESOC_FORCE_PWR_OFF command\n");
 			ret = clink_ops->cmd_exe(ESOC_FORCE_PWR_OFF,
 							esoc_clink);
 		} else {
 			if (mdm_dbg_stall_cmd(ESOC_PWR_OFF))
 				/* Since power off command is masked
 				 * we return success, and leave the state
 				 * of the command engine as is.
 				 */
 				return 0;
 			dev_dbg(&esoc_clink->dev, "Sending sysmon-shutdown\n");
 			esoc_mdm_log("Executing the ESOC_PWR_OFF command\n");
 			ret = clink_ops->cmd_exe(ESOC_PWR_OFF, esoc_clink);
 		}
 		if (ret) {
 			esoc_mdm_log(
 			"Executing the ESOC_PWR_OFF command failed\n");
 			dev_err(&esoc_clink->dev, "failed to exe power off\n");
 			return ret;
 		}
 		esoc_client_link_power_off(esoc_clink, false);
 		/* Pull the reset line low to turn off the device */
 		clink_ops->cmd_exe(ESOC_FORCE_PWR_OFF, esoc_clink);
 		mdm_drv->mode = PWR_OFF;
 	}
 	esoc_mdm_log("Shutdown completed\n");
 	return 0;
 }

 static void mdm_subsys_retry_powerup_cleanup(struct esoc_clink *esoc_clink)
 {
 	struct mdm_ctrl *mdm = get_esoc_clink_data(esoc_clink);
 	struct mdm_drv *mdm_drv = esoc_get_drv_data(esoc_clink);

 	esoc_mdm_log("Doing cleanup\n");

 	esoc_client_link_power_off(esoc_clink, false);
 	mdm_disable_irqs(mdm);
 	mdm_drv->pon_state = PON_INIT;
 	reinit_completion(&mdm_drv->pon_done);
 	reinit_completion(&mdm_drv->req_eng_wait);
 }

 /* Returns 0 to proceed towards another retry, or an error code to quit */
 static int mdm_handle_boot_fail(struct esoc_clink *esoc_clink, u8 *pon_trial)
 {
 	struct mdm_ctrl *mdm = get_esoc_clink_data(esoc_clink);

 	switch (boot_fail_action) {
 	case BOOT_FAIL_ACTION_RETRY:
 		mdm_subsys_retry_powerup_cleanup(esoc_clink);
 		esoc_mdm_log("Request to retry a warm reset\n");
 		(*pon_trial)++;
 		break;
 	/*
 	 * Issue a shutdown here and rerun the powerup again.
 	 * This way it becomes a cold reset. Else, we end up
 	 * issuing a cold reset & a warm reset back to back.
 	 */
 	case BOOT_FAIL_ACTION_COLD_RESET:
 		mdm_subsys_retry_powerup_cleanup(esoc_clink);
 		esoc_mdm_log("Doing cold reset by power-down and warm reset\n");
 		(*pon_trial)++;
 		mdm_power_down(mdm);
 		break;
 	case BOOT_FAIL_ACTION_PANIC:
 		esoc_mdm_log("Calling panic!!\n");
 		panic("Panic requested on external modem boot failure\n");
 		break;
 	case BOOT_FAIL_ACTION_NOP:
 		esoc_mdm_log("Leaving the modem in its curent state\n");
 		return -EIO;
 	case BOOT_FAIL_ACTION_SHUTDOWN:
 	default:
 		mdm_subsys_retry_powerup_cleanup(esoc_clink);
 		esoc_mdm_log("Shutdown the modem and quit\n");
 		mdm_power_down(mdm);
 		return -EIO;
 	}

 	return 0;
 }

 static int mdm_subsys_powerup(const struct subsys_desc *crashed_subsys)
 {
 	int ret;
 	struct esoc_clink *esoc_clink =
 				container_of(crashed_subsys, struct esoc_clink,
 								subsys);
 	struct mdm_drv *mdm_drv = esoc_get_drv_data(esoc_clink);
 	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;
 	int timeout = INT_MAX;
 	u8 pon_trial = 1;

 	esoc_mdm_log("Powerup request from SSR\n");

 	do {
 		esoc_mdm_log("Boot trial: %d\n", pon_trial);
 		if (!esoc_clink->auto_boot &&
 			!esoc_req_eng_enabled(esoc_clink)) {
 			esoc_mdm_log("Wait for req eng registration\n");
 			dev_dbg(&esoc_clink->dev,
 					"Wait for req eng registration\n");
 			wait_for_completion(&mdm_drv->req_eng_wait);
 		}
 		esoc_mdm_log("Req eng available\n");
 		if (mdm_drv->mode == PWR_OFF) {
 			esoc_mdm_log("In normal power-on mode\n");
 			if (mdm_dbg_stall_cmd(ESOC_PWR_ON))
 				return -EBUSY;
 			esoc_mdm_log("Executing the ESOC_PWR_ON command\n");
 			ret = clink_ops->cmd_exe(ESOC_PWR_ON, esoc_clink);
 			if (ret) {
 				esoc_mdm_log("ESOC_PWR_ON command failed\n");
 				dev_err(&esoc_clink->dev, "pwr on fail\n");
 				return ret;
 			}
 			esoc_client_link_power_on(esoc_clink, false);
 		} else if (mdm_drv->mode == IN_DEBUG) {
 			esoc_mdm_log("In SSR power-on mode\n");
 			esoc_mdm_log("Executing the ESOC_EXIT_DEBUG command\n");
 			ret = clink_ops->cmd_exe(ESOC_EXIT_DEBUG, esoc_clink);
 			if (ret) {
 				esoc_mdm_log(
 				"ESOC_EXIT_DEBUG command failed\n");
 				dev_err(&esoc_clink->dev,
 						"cannot exit debug mode\n");
 				return ret;
 			}
 			mdm_drv->mode = PWR_OFF;
 			esoc_mdm_log("Executing the ESOC_PWR_ON command\n");
 			ret = clink_ops->cmd_exe(ESOC_PWR_ON, esoc_clink);
 			if (ret) {
 				dev_err(&esoc_clink->dev, "pwr on fail\n");
 				return ret;
 			}
 			esoc_client_link_power_on(esoc_clink, true);
 		}

 		/*
 		 * In autoboot case, it is possible that we can forever wait for
 		 * boot completion, when esoc fails to boot. This is because
 		 * there is no helper application which can alert esoc driver
 		 * about boot failure. Prevent going to wait forever in such
 		 * case.
 		 */
 		if (esoc_clink->auto_boot)
 			timeout = 10 * HZ;
 		esoc_mdm_log(
 		"Modem turned-on. Waiting for pon_done notification..\n");
 		ret = wait_for_completion_timeout(&mdm_drv->pon_done, timeout);
 		if (mdm_drv->pon_state == PON_FAIL || ret <= 0) {
 			dev_err(&esoc_clink->dev, "booting failed\n");
 			esoc_mdm_log("booting failed\n");
 			ret = mdm_handle_boot_fail(esoc_clink, &pon_trial);
 			if (ret)
 				return ret;
 		} else if (mdm_drv->pon_state == PON_RETRY) {
 			esoc_mdm_log(
 			"Boot failed. Doing cleanup and attempting to retry\n");
 			pon_trial++;
 			mdm_subsys_retry_powerup_cleanup(esoc_clink);
 		} else if (mdm_drv->pon_state == PON_SUCCESS) {
 			break;
 		}
 	} while (pon_trial <= n_pon_tries);

 	return 0;
 }

 static int mdm_subsys_ramdumps(int want_dumps,
 				const struct subsys_desc *crashed_subsys)
 {
 	int ret;
 	struct esoc_clink *esoc_clink =
 				container_of(crashed_subsys, struct esoc_clink,
 								subsys);
 	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;

 	esoc_mdm_log("Ramdumps called from SSR\n");

 	if (want_dumps) {
 		esoc_mdm_log("Executing the ESOC_EXE_DEBUG command\n");
 		ret = clink_ops->cmd_exe(ESOC_EXE_DEBUG, esoc_clink);
 		if (ret) {
 			esoc_mdm_log(
 			"Failed executing the ESOC_EXE_DEBUG command\n");
 			dev_err(&esoc_clink->dev, "debugging failed\n");
 			return ret;
 		}
 	}
 	return 0;
 }

 static int mdm_register_ssr(struct esoc_clink *esoc_clink)
 {
 	struct subsys_desc *subsys = &esoc_clink->subsys;

 	subsys->shutdown = mdm_subsys_shutdown;
 	subsys->ramdump = mdm_subsys_ramdumps;
 	subsys->powerup = mdm_subsys_powerup;
 	subsys->crash_shutdown = mdm_crash_shutdown;
 	return esoc_clink_register_ssr(esoc_clink);
 }

 int esoc_ssr_probe(struct esoc_clink *esoc_clink, struct esoc_drv *drv)
 {
 	int ret;
 	struct mdm_drv *mdm_drv;
 	struct esoc_eng *esoc_eng;

 	mdm_drv = devm_kzalloc(&esoc_clink->dev, sizeof(*mdm_drv), GFP_KERNEL);
 	if (IS_ERR_OR_NULL(mdm_drv))
 		return PTR_ERR(mdm_drv);
 	esoc_eng = &mdm_drv->cmd_eng;
 	esoc_eng->handle_clink_evt = mdm_handle_clink_evt;
 	ret = esoc_clink_register_cmd_eng(esoc_clink, esoc_eng);
 	if (ret) {
 		dev_err(&esoc_clink->dev, "failed to register cmd engine\n");
 		return ret;
 	}
 	ret = mdm_register_ssr(esoc_clink);
 	if (ret)
 		goto ssr_err;
 	mdm_drv->mdm_queue = alloc_workqueue("mdm_drv_queue", 0, 0);
 	if (!mdm_drv->mdm_queue) {
 		dev_err(&esoc_clink->dev, "could not create mdm_queue\n");
 		goto queue_err;
 	}
 	esoc_set_drv_data(esoc_clink, mdm_drv);
 	init_completion(&mdm_drv->pon_done);
 	init_completion(&mdm_drv->req_eng_wait);
 	INIT_WORK(&mdm_drv->ssr_work, mdm_ssr_fn);
 	mdm_drv->esoc_clink = esoc_clink;
 	mdm_drv->mode = PWR_OFF;
 	mdm_drv->pon_state = PON_INIT;
 	mdm_drv->esoc_restart.notifier_call = esoc_msm_restart_handler;
 	ret = register_reboot_notifier(&mdm_drv->esoc_restart);
 	if (ret)
 		dev_err(&esoc_clink->dev, "register for reboot failed\n");
 	ret = mdm_dbg_eng_init(drv, esoc_clink);
 	if (ret) {
 		debug_init_done = false;
 		dev_err(&esoc_clink->dev, "dbg engine failure\n");
 	} else {
 		dev_dbg(&esoc_clink->dev, "dbg engine initialized\n");
 		debug_init_done = true;
 	}

 	return 0;
 queue_err:
 	esoc_clink_unregister_ssr(esoc_clink);
 ssr_err:
 	esoc_clink_unregister_cmd_eng(esoc_clink, esoc_eng);
 	return ret;
 }

 static struct esoc_compat compat_table[] = {
 	{
 		.name = "MDM9x55",
 		.data = NULL,
 	},
 	{
 		.name = "SDX50M",
 		.data = NULL,
 	},
 };

 static struct esoc_drv esoc_ssr_drv = {
 	.owner = THIS_MODULE,
 	.probe = esoc_ssr_probe,
 	.compat_table = compat_table,
 	.compat_entries = ARRAY_SIZE(compat_table),
 	.driver = {
 		.name = "mdm-4x",
 	},
 };

 int __init esoc_ssr_init(void)
 {
 	return esoc_drv_register(&esoc_ssr_drv);
 }
 module_init(esoc_ssr_init);
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (c) 2013-2015, 2017-2018, The Linux Foundation. All rights reserved.
	*/

	#include <linux/delay.h>
	#include <linux/workqueue.h>
	#include <linux/reboot.h>
	#include <linux/of.h>
	#include <linux/esoc_client.h>
	#include "esoc.h"
	#include "esoc-mdm.h"
	#include "mdm-dbg.h"

	/* Default number of powerup trial requests per session */
	#define ESOC_DEF_PON_REQ 2
	static unsigned int n_pon_tries = ESOC_DEF_PON_REQ;
	module_param(n_pon_tries, uint, 0644);
	MODULE_PARM_DESC(n_pon_tries,
	"Number of power-on retrials allowed upon boot failure");

	enum esoc_boot_fail_action {
	BOOT_FAIL_ACTION_RETRY,
	BOOT_FAIL_ACTION_COLD_RESET,
	BOOT_FAIL_ACTION_SHUTDOWN,
	BOOT_FAIL_ACTION_PANIC,
	BOOT_FAIL_ACTION_NOP,
	};

	static unsigned int boot_fail_action = BOOT_FAIL_ACTION_NOP;
	module_param(boot_fail_action, uint, 0644);
	MODULE_PARM_DESC(boot_fail_action,
	"Actions: 0:Retry PON; 1:Cold reset; 2:Power-down; 3:APQ Panic; 4:No action");

	enum esoc_pon_state {
	PON_INIT,
	PON_SUCCESS,
	PON_RETRY,
	PON_FAIL
	};

	enum {
	PWR_OFF = 0x1,
	PWR_ON,
	BOOT,
	RUN,
	CRASH,
	IN_DEBUG,
	SHUTDOWN,
	RESET,
	PEER_CRASH,
	};

	struct mdm_drv {
	unsigned int mode;
	struct esoc_eng cmd_eng;
	struct completion pon_done;
	struct completion req_eng_wait;
	struct esoc_clink *esoc_clink;
	enum esoc_pon_state pon_state;
	struct workqueue_struct *mdm_queue;
	struct work_struct ssr_work;
	struct notifier_block esoc_restart;
	};
	#define to_mdm_drv(d) container_of(d, struct mdm_drv, cmd_eng)

	static int esoc_msm_restart_handler(struct notifier_block *nb,
	unsigned long action, void *data)
	{
	struct mdm_drv *mdm_drv = container_of(nb, struct mdm_drv,
	esoc_restart);
	struct esoc_clink *esoc_clink = mdm_drv->esoc_clink;
	const struct esoc_clink_ops *const clink_ops = esoc_clink->clink_ops;

	if (action == SYS_RESTART) {
	if (mdm_dbg_stall_notify(ESOC_PRIMARY_REBOOT))
	return NOTIFY_OK;
	esoc_mdm_log(
	"Reboot notifier: Notifying esoc of cold reboot\n");
	dev_dbg(&esoc_clink->dev, "Notifying esoc of cold reboot\n");
	clink_ops->notify(ESOC_PRIMARY_REBOOT, esoc_clink);
	}
	return NOTIFY_OK;
	}
	static void mdm_handle_clink_evt(enum esoc_evt evt,
	struct esoc_eng *eng)
	{
	struct mdm_drv *mdm_drv = to_mdm_drv(eng);
	bool unexpected_state = false;

	switch (evt) {
	case ESOC_INVALID_STATE:
	esoc_mdm_log(
	"ESOC_INVALID_STATE: Calling complete with state: PON_FAIL\n");
	mdm_drv->pon_state = PON_FAIL;
	complete(&mdm_drv->pon_done);
	break;
	case ESOC_RUN_STATE:
	esoc_mdm_log(
	"ESOC_RUN_STATE: Calling complete with state: PON_SUCCESS\n");
	mdm_drv->pon_state = PON_SUCCESS;
	mdm_drv->mode = RUN,
	complete(&mdm_drv->pon_done);
	break;
	case ESOC_RETRY_PON_EVT:
	esoc_mdm_log(
	"ESOC_RETRY_PON_EVT: Calling complete with state: PON_RETRY\n");
	mdm_drv->pon_state = PON_RETRY;
	complete(&mdm_drv->pon_done);
	break;
	case ESOC_UNEXPECTED_RESET:
	esoc_mdm_log("evt_state: ESOC_UNEXPECTED_RESET\n");
	unexpected_state = true;
	case ESOC_ERR_FATAL:
	if (!unexpected_state)
	esoc_mdm_log("evt_state: ESOC_ERR_FATAL\n");

	/*
	* Modem can crash while we are waiting for pon_done during
	* a subsystem_get(). Setting mode to CRASH will prevent a
	* subsequent subsystem_get() from entering poweron ops. Avoid
	* this by seting mode to CRASH only if device was up and
	* running.
	*/
	if (mdm_drv->mode == CRASH)
	esoc_mdm_log(
	"Modem in crash state already. Ignoring.\n");
	if (mdm_drv->mode != RUN)
	esoc_mdm_log("Modem not up. Ignoring.\n");
	if (mdm_drv->mode == CRASH \|\| mdm_drv->mode != RUN)
	return;
	mdm_drv->mode = CRASH;
	queue_work(mdm_drv->mdm_queue, &mdm_drv->ssr_work);
	break;
	case ESOC_REQ_ENG_ON:
	esoc_mdm_log(
	"evt_state: ESOC_REQ_ENG_ON; Registered a req engine\n");
	complete(&mdm_drv->req_eng_wait);
	break;
	default:
	break;
	}
	}

	static void mdm_ssr_fn(struct work_struct *work)
	{
	struct mdm_drv *mdm_drv = container_of(work, struct mdm_drv, ssr_work);
	struct mdm_ctrl *mdm = get_esoc_clink_data(mdm_drv->esoc_clink);

	mdm_wait_for_status_low(mdm, false);

	esoc_mdm_log("Starting SSR work\n");

	/*
	* If restarting esoc fails, the SSR framework triggers a kernel panic
	*/
	esoc_clink_request_ssr(mdm_drv->esoc_clink);
	}

	static void esoc_client_link_power_on(struct esoc_clink *esoc_clink,
	bool mdm_crashed)
	{
	int i;
	struct esoc_client_hook *client_hook;

	dev_dbg(&esoc_clink->dev, "Calling power_on hooks\n");
	esoc_mdm_log(
	"Calling power_on hooks with crash state: %d\n", mdm_crashed);

	for (i = 0; i < ESOC_MAX_HOOKS; i++) {
	client_hook = esoc_clink->client_hook[i];
	if (client_hook && client_hook->esoc_link_power_on)
	client_hook->esoc_link_power_on(client_hook->priv,
	mdm_crashed);
	}
	}

	static void esoc_client_link_power_off(struct esoc_clink *esoc_clink,
	bool mdm_crashed)
	{
	int i;
	struct esoc_client_hook *client_hook;

	dev_dbg(&esoc_clink->dev, "Calling power_off hooks\n");
	esoc_mdm_log(
	"Calling power_off hooks with crash state: %d\n", mdm_crashed);

	for (i = 0; i < ESOC_MAX_HOOKS; i++) {
	client_hook = esoc_clink->client_hook[i];
	if (client_hook && client_hook->esoc_link_power_off) {
	client_hook->esoc_link_power_off(client_hook->priv,
	mdm_crashed);
	}
	}
	}

	static void mdm_crash_shutdown(const struct subsys_desc *mdm_subsys)
	{
	struct esoc_clink *esoc_clink =
	container_of(mdm_subsys,
	struct esoc_clink,
	subsys);
	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;

	esoc_mdm_log("MDM crashed notification from SSR\n");

	if (mdm_dbg_stall_notify(ESOC_PRIMARY_CRASH))
	return;
	clink_ops->notify(ESOC_PRIMARY_CRASH, esoc_clink);
	}

	static int mdm_subsys_shutdown(const struct subsys_desc *crashed_subsys,
	bool force_stop)
	{
	int ret;
	struct esoc_clink *esoc_clink =
	container_of(crashed_subsys, struct esoc_clink, subsys);
	struct mdm_drv *mdm_drv = esoc_get_drv_data(esoc_clink);
	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;

	esoc_mdm_log("Shutdown request from SSR\n");

	if (mdm_drv->mode == CRASH \|\| mdm_drv->mode == PEER_CRASH) {
	esoc_mdm_log("Shutdown in crash mode\n");
	if (mdm_dbg_stall_cmd(ESOC_PREPARE_DEBUG))
	/* We want to mask debug command.
	* In this case return success
	* to move to next stage
	*/
	return 0;

	esoc_clink_queue_request(ESOC_REQ_CRASH_SHUTDOWN, esoc_clink);
	esoc_client_link_power_off(esoc_clink, true);

	esoc_mdm_log("Executing the ESOC_PREPARE_DEBUG command\n");
	ret = clink_ops->cmd_exe(ESOC_PREPARE_DEBUG,
	esoc_clink);
	if (ret) {
	esoc_mdm_log("ESOC_PREPARE_DEBUG command failed\n");
	dev_err(&esoc_clink->dev, "failed to enter debug\n");
	return ret;
	}
	mdm_drv->mode = IN_DEBUG;
	} else if (!force_stop) {
	esoc_mdm_log("Graceful shutdown mode\n");
	if (esoc_clink->subsys.sysmon_shutdown_ret) {
	esoc_mdm_log(
	"Executing the ESOC_FORCE_PWR_OFF command\n");
	ret = clink_ops->cmd_exe(ESOC_FORCE_PWR_OFF,
	esoc_clink);
	} else {
	if (mdm_dbg_stall_cmd(ESOC_PWR_OFF))
	/* Since power off command is masked
	* we return success, and leave the state
	* of the command engine as is.
	*/
	return 0;
	dev_dbg(&esoc_clink->dev, "Sending sysmon-shutdown\n");
	esoc_mdm_log("Executing the ESOC_PWR_OFF command\n");
	ret = clink_ops->cmd_exe(ESOC_PWR_OFF, esoc_clink);
	}
	if (ret) {
	esoc_mdm_log(
	"Executing the ESOC_PWR_OFF command failed\n");
	dev_err(&esoc_clink->dev, "failed to exe power off\n");
	return ret;
	}
	esoc_client_link_power_off(esoc_clink, false);
	/* Pull the reset line low to turn off the device */
	clink_ops->cmd_exe(ESOC_FORCE_PWR_OFF, esoc_clink);
	mdm_drv->mode = PWR_OFF;
	}
	esoc_mdm_log("Shutdown completed\n");
	return 0;
	}

	static void mdm_subsys_retry_powerup_cleanup(struct esoc_clink *esoc_clink)
	{
	struct mdm_ctrl *mdm = get_esoc_clink_data(esoc_clink);
	struct mdm_drv *mdm_drv = esoc_get_drv_data(esoc_clink);

	esoc_mdm_log("Doing cleanup\n");

	esoc_client_link_power_off(esoc_clink, false);
	mdm_disable_irqs(mdm);
	mdm_drv->pon_state = PON_INIT;
	reinit_completion(&mdm_drv->pon_done);
	reinit_completion(&mdm_drv->req_eng_wait);
	}

	/* Returns 0 to proceed towards another retry, or an error code to quit */
	static int mdm_handle_boot_fail(struct esoc_clink esoc_clink, u8 pon_trial)
	{
	struct mdm_ctrl *mdm = get_esoc_clink_data(esoc_clink);

	switch (boot_fail_action) {
	case BOOT_FAIL_ACTION_RETRY:
	mdm_subsys_retry_powerup_cleanup(esoc_clink);
	esoc_mdm_log("Request to retry a warm reset\n");
	(*pon_trial)++;
	break;
	/*
	* Issue a shutdown here and rerun the powerup again.
	* This way it becomes a cold reset. Else, we end up
	* issuing a cold reset & a warm reset back to back.
	*/
	case BOOT_FAIL_ACTION_COLD_RESET:
	mdm_subsys_retry_powerup_cleanup(esoc_clink);
	esoc_mdm_log("Doing cold reset by power-down and warm reset\n");
	(*pon_trial)++;
	mdm_power_down(mdm);
	break;
	case BOOT_FAIL_ACTION_PANIC:
	esoc_mdm_log("Calling panic!!\n");
	panic("Panic requested on external modem boot failure\n");
	break;
	case BOOT_FAIL_ACTION_NOP:
	esoc_mdm_log("Leaving the modem in its curent state\n");
	return -EIO;
	case BOOT_FAIL_ACTION_SHUTDOWN:
	default:
	mdm_subsys_retry_powerup_cleanup(esoc_clink);
	esoc_mdm_log("Shutdown the modem and quit\n");
	mdm_power_down(mdm);
	return -EIO;
	}

	return 0;
	}

	static int mdm_subsys_powerup(const struct subsys_desc *crashed_subsys)
	{
	int ret;
	struct esoc_clink *esoc_clink =
	container_of(crashed_subsys, struct esoc_clink,
	subsys);
	struct mdm_drv *mdm_drv = esoc_get_drv_data(esoc_clink);
	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;
	int timeout = INT_MAX;
	u8 pon_trial = 1;

	esoc_mdm_log("Powerup request from SSR\n");

	do {
	esoc_mdm_log("Boot trial: %d\n", pon_trial);
	if (!esoc_clink->auto_boot &&
	!esoc_req_eng_enabled(esoc_clink)) {
	esoc_mdm_log("Wait for req eng registration\n");
	dev_dbg(&esoc_clink->dev,
	"Wait for req eng registration\n");
	wait_for_completion(&mdm_drv->req_eng_wait);
	}
	esoc_mdm_log("Req eng available\n");
	if (mdm_drv->mode == PWR_OFF) {
	esoc_mdm_log("In normal power-on mode\n");
	if (mdm_dbg_stall_cmd(ESOC_PWR_ON))
	return -EBUSY;
	esoc_mdm_log("Executing the ESOC_PWR_ON command\n");
	ret = clink_ops->cmd_exe(ESOC_PWR_ON, esoc_clink);
	if (ret) {
	esoc_mdm_log("ESOC_PWR_ON command failed\n");
	dev_err(&esoc_clink->dev, "pwr on fail\n");
	return ret;
	}
	esoc_client_link_power_on(esoc_clink, false);
	} else if (mdm_drv->mode == IN_DEBUG) {
	esoc_mdm_log("In SSR power-on mode\n");
	esoc_mdm_log("Executing the ESOC_EXIT_DEBUG command\n");
	ret = clink_ops->cmd_exe(ESOC_EXIT_DEBUG, esoc_clink);
	if (ret) {
	esoc_mdm_log(
	"ESOC_EXIT_DEBUG command failed\n");
	dev_err(&esoc_clink->dev,
	"cannot exit debug mode\n");
	return ret;
	}
	mdm_drv->mode = PWR_OFF;
	esoc_mdm_log("Executing the ESOC_PWR_ON command\n");
	ret = clink_ops->cmd_exe(ESOC_PWR_ON, esoc_clink);
	if (ret) {
	dev_err(&esoc_clink->dev, "pwr on fail\n");
	return ret;
	}
	esoc_client_link_power_on(esoc_clink, true);
	}

	/*
	* In autoboot case, it is possible that we can forever wait for
	* boot completion, when esoc fails to boot. This is because
	* there is no helper application which can alert esoc driver
	* about boot failure. Prevent going to wait forever in such
	* case.
	*/
	if (esoc_clink->auto_boot)
	timeout = 10 * HZ;
	esoc_mdm_log(
	"Modem turned-on. Waiting for pon_done notification..\n");
	ret = wait_for_completion_timeout(&mdm_drv->pon_done, timeout);
	if (mdm_drv->pon_state == PON_FAIL \|\| ret <= 0) {
	dev_err(&esoc_clink->dev, "booting failed\n");
	esoc_mdm_log("booting failed\n");
	ret = mdm_handle_boot_fail(esoc_clink, &pon_trial);
	if (ret)
	return ret;
	} else if (mdm_drv->pon_state == PON_RETRY) {
	esoc_mdm_log(
	"Boot failed. Doing cleanup and attempting to retry\n");
	pon_trial++;
	mdm_subsys_retry_powerup_cleanup(esoc_clink);
	} else if (mdm_drv->pon_state == PON_SUCCESS) {
	break;
	}
	} while (pon_trial <= n_pon_tries);

	return 0;
	}

	static int mdm_subsys_ramdumps(int want_dumps,
	const struct subsys_desc *crashed_subsys)
	{
	int ret;
	struct esoc_clink *esoc_clink =
	container_of(crashed_subsys, struct esoc_clink,
	subsys);
	const struct esoc_clink_ops * const clink_ops = esoc_clink->clink_ops;

	esoc_mdm_log("Ramdumps called from SSR\n");

	if (want_dumps) {
	esoc_mdm_log("Executing the ESOC_EXE_DEBUG command\n");
	ret = clink_ops->cmd_exe(ESOC_EXE_DEBUG, esoc_clink);
	if (ret) {
	esoc_mdm_log(
	"Failed executing the ESOC_EXE_DEBUG command\n");
	dev_err(&esoc_clink->dev, "debugging failed\n");
	return ret;
	}
	}
	return 0;
	}

	static int mdm_register_ssr(struct esoc_clink *esoc_clink)
	{
	struct subsys_desc *subsys = &esoc_clink->subsys;

	subsys->shutdown = mdm_subsys_shutdown;
	subsys->ramdump = mdm_subsys_ramdumps;
	subsys->powerup = mdm_subsys_powerup;
	subsys->crash_shutdown = mdm_crash_shutdown;
	return esoc_clink_register_ssr(esoc_clink);
	}

	int esoc_ssr_probe(struct esoc_clink esoc_clink, struct esoc_drv drv)
	{
	int ret;
	struct mdm_drv *mdm_drv;
	struct esoc_eng *esoc_eng;

	mdm_drv = devm_kzalloc(&esoc_clink->dev, sizeof(*mdm_drv), GFP_KERNEL);
	if (IS_ERR_OR_NULL(mdm_drv))
	return PTR_ERR(mdm_drv);
	esoc_eng = &mdm_drv->cmd_eng;
	esoc_eng->handle_clink_evt = mdm_handle_clink_evt;
	ret = esoc_clink_register_cmd_eng(esoc_clink, esoc_eng);
	if (ret) {
	dev_err(&esoc_clink->dev, "failed to register cmd engine\n");
	return ret;
	}
	ret = mdm_register_ssr(esoc_clink);
	if (ret)
	goto ssr_err;
	mdm_drv->mdm_queue = alloc_workqueue("mdm_drv_queue", 0, 0);
	if (!mdm_drv->mdm_queue) {
	dev_err(&esoc_clink->dev, "could not create mdm_queue\n");
	goto queue_err;
	}
	esoc_set_drv_data(esoc_clink, mdm_drv);
	init_completion(&mdm_drv->pon_done);
	init_completion(&mdm_drv->req_eng_wait);
	INIT_WORK(&mdm_drv->ssr_work, mdm_ssr_fn);
	mdm_drv->esoc_clink = esoc_clink;
	mdm_drv->mode = PWR_OFF;
	mdm_drv->pon_state = PON_INIT;
	mdm_drv->esoc_restart.notifier_call = esoc_msm_restart_handler;
	ret = register_reboot_notifier(&mdm_drv->esoc_restart);
	if (ret)
	dev_err(&esoc_clink->dev, "register for reboot failed\n");
	ret = mdm_dbg_eng_init(drv, esoc_clink);
	if (ret) {
	debug_init_done = false;
	dev_err(&esoc_clink->dev, "dbg engine failure\n");
	} else {
	dev_dbg(&esoc_clink->dev, "dbg engine initialized\n");
	debug_init_done = true;
	}

	return 0;
	queue_err:
	esoc_clink_unregister_ssr(esoc_clink);
	ssr_err:
	esoc_clink_unregister_cmd_eng(esoc_clink, esoc_eng);
	return ret;
	}

	static struct esoc_compat compat_table[] = {
	{
	.name = "MDM9x55",
	.data = NULL,
	},
	{
	.name = "SDX50M",
	.data = NULL,
	},
	};

	static struct esoc_drv esoc_ssr_drv = {
	.owner = THIS_MODULE,
	.probe = esoc_ssr_probe,
	.compat_table = compat_table,
	.compat_entries = ARRAY_SIZE(compat_table),
	.driver = {
	.name = "mdm-4x",
	},
	};

	int __init esoc_ssr_init(void)
	{
	return esoc_drv_register(&esoc_ssr_drv);
	}
	module_init(esoc_ssr_init);
	MODULE_LICENSE("GPL v2");