drivers/firmware/qcom_scm.c - kernel/msm-4.19 - Gitiles

 /*
  * Qualcomm SCM driver
  *
  * Copyright (c) 2010,2015, The Linux Foundation. All rights reserved.
  * Copyright (C) 2015 Linaro Ltd.
  *
  * 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/platform_device.h>
 #include <linux/init.h>
 #include <linux/cpumask.h>
 #include <linux/export.h>
 #include <linux/dma-mapping.h>
 #include <linux/types.h>
 #include <linux/qcom_scm.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/clk.h>
 #include <linux/reset-controller.h>

 #include "qcom_scm.h"

 #define SCM_HAS_CORE_CLK	BIT(0)
 #define SCM_HAS_IFACE_CLK	BIT(1)
 #define SCM_HAS_BUS_CLK		BIT(2)

 struct qcom_scm {
 	struct device *dev;
 	struct clk *core_clk;
 	struct clk *iface_clk;
 	struct clk *bus_clk;
 	struct reset_controller_dev reset;
 };

 static struct qcom_scm *__scm;

 static int qcom_scm_clk_enable(void)
 {
 	int ret;

 	ret = clk_prepare_enable(__scm->core_clk);
 	if (ret)
 		goto bail;

 	ret = clk_prepare_enable(__scm->iface_clk);
 	if (ret)
 		goto disable_core;

 	ret = clk_prepare_enable(__scm->bus_clk);
 	if (ret)
 		goto disable_iface;

 	return 0;

 disable_iface:
 	clk_disable_unprepare(__scm->iface_clk);
 disable_core:
 	clk_disable_unprepare(__scm->core_clk);
 bail:
 	return ret;
 }

 static void qcom_scm_clk_disable(void)
 {
 	clk_disable_unprepare(__scm->core_clk);
 	clk_disable_unprepare(__scm->iface_clk);
 	clk_disable_unprepare(__scm->bus_clk);
 }

 /**
  * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
  * @entry: Entry point function for the cpus
  * @cpus: The cpumask of cpus that will use the entry point
  *
  * Set the cold boot address of the cpus. Any cpu outside the supported
  * range would be removed from the cpu present mask.
  */
 int qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
 {
 	return __qcom_scm_set_cold_boot_addr(entry, cpus);
 }
 EXPORT_SYMBOL(qcom_scm_set_cold_boot_addr);

 /**
  * qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus
  * @entry: Entry point function for the cpus
  * @cpus: The cpumask of cpus that will use the entry point
  *
  * Set the Linux entry point for the SCM to transfer control to when coming
  * out of a power down. CPU power down may be executed on cpuidle or hotplug.
  */
 int qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)
 {
 	return __qcom_scm_set_warm_boot_addr(__scm->dev, entry, cpus);
 }
 EXPORT_SYMBOL(qcom_scm_set_warm_boot_addr);

 /**
  * qcom_scm_cpu_power_down() - Power down the cpu
  * @flags - Flags to flush cache
  *
  * This is an end point to power down cpu. If there was a pending interrupt,
  * the control would return from this function, otherwise, the cpu jumps to the
  * warm boot entry point set for this cpu upon reset.
  */
 void qcom_scm_cpu_power_down(u32 flags)
 {
 	__qcom_scm_cpu_power_down(flags);
 }
 EXPORT_SYMBOL(qcom_scm_cpu_power_down);

 /**
  * qcom_scm_hdcp_available() - Check if secure environment supports HDCP.
  *
  * Return true if HDCP is supported, false if not.
  */
 bool qcom_scm_hdcp_available(void)
 {
 	int ret = qcom_scm_clk_enable();

 	if (ret)
 		return ret;

 	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_HDCP,
 						QCOM_SCM_CMD_HDCP);

 	qcom_scm_clk_disable();

 	return ret > 0 ? true : false;
 }
 EXPORT_SYMBOL(qcom_scm_hdcp_available);

 /**
  * qcom_scm_hdcp_req() - Send HDCP request.
  * @req: HDCP request array
  * @req_cnt: HDCP request array count
  * @resp: response buffer passed to SCM
  *
  * Write HDCP register(s) through SCM.
  */
 int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
 {
 	int ret = qcom_scm_clk_enable();

 	if (ret)
 		return ret;

 	ret = __qcom_scm_hdcp_req(__scm->dev, req, req_cnt, resp);
 	qcom_scm_clk_disable();
 	return ret;
 }
 EXPORT_SYMBOL(qcom_scm_hdcp_req);

 /**
  * qcom_scm_pas_supported() - Check if the peripheral authentication service is
  *			      available for the given peripherial
  * @peripheral:	peripheral id
  *
  * Returns true if PAS is supported for this peripheral, otherwise false.
  */
 bool qcom_scm_pas_supported(u32 peripheral)
 {
 	int ret;

 	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_PIL,
 					   QCOM_SCM_PAS_IS_SUPPORTED_CMD);
 	if (ret <= 0)
 		return false;

 	return __qcom_scm_pas_supported(__scm->dev, peripheral);
 }
 EXPORT_SYMBOL(qcom_scm_pas_supported);

 /**
  * qcom_scm_pas_init_image() - Initialize peripheral authentication service
  *			       state machine for a given peripheral, using the
  *			       metadata
  * @peripheral: peripheral id
  * @metadata:	pointer to memory containing ELF header, program header table
  *		and optional blob of data used for authenticating the metadata
  *		and the rest of the firmware
  * @size:	size of the metadata
  *
  * Returns 0 on success.
  */
 int qcom_scm_pas_init_image(u32 peripheral, const void *metadata, size_t size)
 {
 	dma_addr_t mdata_phys;
 	void *mdata_buf;
 	int ret;

 	/*
 	 * During the scm call memory protection will be enabled for the meta
 	 * data blob, so make sure it's physically contiguous, 4K aligned and
 	 * non-cachable to avoid XPU violations.
 	 */
 	mdata_buf = dma_alloc_coherent(__scm->dev, size, &mdata_phys,
 				       GFP_KERNEL);
 	if (!mdata_buf) {
 		dev_err(__scm->dev, "Allocation of metadata buffer failed.\n");
 		return -ENOMEM;
 	}
 	memcpy(mdata_buf, metadata, size);

 	ret = qcom_scm_clk_enable();
 	if (ret)
 		goto free_metadata;

 	ret = __qcom_scm_pas_init_image(__scm->dev, peripheral, mdata_phys);

 	qcom_scm_clk_disable();

 free_metadata:
 	dma_free_coherent(__scm->dev, size, mdata_buf, mdata_phys);

 	return ret;
 }
 EXPORT_SYMBOL(qcom_scm_pas_init_image);

 /**
  * qcom_scm_pas_mem_setup() - Prepare the memory related to a given peripheral
  *			      for firmware loading
  * @peripheral:	peripheral id
  * @addr:	start address of memory area to prepare
  * @size:	size of the memory area to prepare
  *
  * Returns 0 on success.
  */
 int qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size)
 {
 	int ret;

 	ret = qcom_scm_clk_enable();
 	if (ret)
 		return ret;

 	ret = __qcom_scm_pas_mem_setup(__scm->dev, peripheral, addr, size);
 	qcom_scm_clk_disable();

 	return ret;
 }
 EXPORT_SYMBOL(qcom_scm_pas_mem_setup);

 /**
  * qcom_scm_pas_auth_and_reset() - Authenticate the given peripheral firmware
  *				   and reset the remote processor
  * @peripheral:	peripheral id
  *
  * Return 0 on success.
  */
 int qcom_scm_pas_auth_and_reset(u32 peripheral)
 {
 	int ret;

 	ret = qcom_scm_clk_enable();
 	if (ret)
 		return ret;

 	ret = __qcom_scm_pas_auth_and_reset(__scm->dev, peripheral);
 	qcom_scm_clk_disable();

 	return ret;
 }
 EXPORT_SYMBOL(qcom_scm_pas_auth_and_reset);

 /**
  * qcom_scm_pas_shutdown() - Shut down the remote processor
  * @peripheral: peripheral id
  *
  * Returns 0 on success.
  */
 int qcom_scm_pas_shutdown(u32 peripheral)
 {
 	int ret;

 	ret = qcom_scm_clk_enable();
 	if (ret)
 		return ret;

 	ret = __qcom_scm_pas_shutdown(__scm->dev, peripheral);
 	qcom_scm_clk_disable();

 	return ret;
 }
 EXPORT_SYMBOL(qcom_scm_pas_shutdown);

 static int qcom_scm_pas_reset_assert(struct reset_controller_dev *rcdev,
 				     unsigned long idx)
 {
 	if (idx != 0)
 		return -EINVAL;

 	return __qcom_scm_pas_mss_reset(__scm->dev, 1);
 }

 static int qcom_scm_pas_reset_deassert(struct reset_controller_dev *rcdev,
 				       unsigned long idx)
 {
 	if (idx != 0)
 		return -EINVAL;

 	return __qcom_scm_pas_mss_reset(__scm->dev, 0);
 }

 static const struct reset_control_ops qcom_scm_pas_reset_ops = {
 	.assert = qcom_scm_pas_reset_assert,
 	.deassert = qcom_scm_pas_reset_deassert,
 };

 /**
  * qcom_scm_is_available() - Checks if SCM is available
  */
 bool qcom_scm_is_available(void)
 {
 	return !!__scm;
 }
 EXPORT_SYMBOL(qcom_scm_is_available);

 int qcom_scm_set_remote_state(u32 state, u32 id)
 {
 	return __qcom_scm_set_remote_state(__scm->dev, state, id);
 }
 EXPORT_SYMBOL(qcom_scm_set_remote_state);

 static int qcom_scm_probe(struct platform_device *pdev)
 {
 	struct qcom_scm *scm;
 	unsigned long clks;
 	int ret;

 	scm = devm_kzalloc(&pdev->dev, sizeof(*scm), GFP_KERNEL);
 	if (!scm)
 		return -ENOMEM;

 	clks = (unsigned long)of_device_get_match_data(&pdev->dev);
 	if (clks & SCM_HAS_CORE_CLK) {
 		scm->core_clk = devm_clk_get(&pdev->dev, "core");
 		if (IS_ERR(scm->core_clk)) {
 			if (PTR_ERR(scm->core_clk) != -EPROBE_DEFER)
 				dev_err(&pdev->dev,
 					"failed to acquire core clk\n");
 			return PTR_ERR(scm->core_clk);
 		}
 	}

 	if (clks & SCM_HAS_IFACE_CLK) {
 		scm->iface_clk = devm_clk_get(&pdev->dev, "iface");
 		if (IS_ERR(scm->iface_clk)) {
 			if (PTR_ERR(scm->iface_clk) != -EPROBE_DEFER)
 				dev_err(&pdev->dev,
 					"failed to acquire iface clk\n");
 			return PTR_ERR(scm->iface_clk);
 		}
 	}

 	if (clks & SCM_HAS_BUS_CLK) {
 		scm->bus_clk = devm_clk_get(&pdev->dev, "bus");
 		if (IS_ERR(scm->bus_clk)) {
 			if (PTR_ERR(scm->bus_clk) != -EPROBE_DEFER)
 				dev_err(&pdev->dev,
 					"failed to acquire bus clk\n");
 			return PTR_ERR(scm->bus_clk);
 		}
 	}

 	scm->reset.ops = &qcom_scm_pas_reset_ops;
 	scm->reset.nr_resets = 1;
 	scm->reset.of_node = pdev->dev.of_node;
 	ret = devm_reset_controller_register(&pdev->dev, &scm->reset);
 	if (ret)
 		return ret;

 	/* vote for max clk rate for highest performance */
 	ret = clk_set_rate(scm->core_clk, INT_MAX);
 	if (ret)
 		return ret;

 	__scm = scm;
 	__scm->dev = &pdev->dev;

 	__qcom_scm_init();

 	return 0;
 }

 static const struct of_device_id qcom_scm_dt_match[] = {
 	{ .compatible = "qcom,scm-apq8064",
 	  /* FIXME: This should have .data = (void *) SCM_HAS_CORE_CLK */
 	},
 	{ .compatible = "qcom,scm-msm8660",
 	  .data = (void *) SCM_HAS_CORE_CLK,
 	},
 	{ .compatible = "qcom,scm-msm8960",
 	  .data = (void *) SCM_HAS_CORE_CLK,
 	},
 	{ .compatible = "qcom,scm-msm8996",
 	  .data = NULL, /* no clocks */
 	},
 	{ .compatible = "qcom,scm",
 	  .data = (void *)(SCM_HAS_CORE_CLK
 			   | SCM_HAS_IFACE_CLK
 			   | SCM_HAS_BUS_CLK),
 	},
 	{}
 };

 static struct platform_driver qcom_scm_driver = {
 	.driver = {
 		.name	= "qcom_scm",
 		.of_match_table = qcom_scm_dt_match,
 	},
 	.probe = qcom_scm_probe,
 };

 static int __init qcom_scm_init(void)
 {
 	struct device_node *np, *fw_np;
 	int ret;

 	fw_np = of_find_node_by_name(NULL, "firmware");

 	if (!fw_np)
 		return -ENODEV;

 	np = of_find_matching_node(fw_np, qcom_scm_dt_match);

 	if (!np) {
 		of_node_put(fw_np);
 		return -ENODEV;
 	}

 	of_node_put(np);

 	ret = of_platform_populate(fw_np, qcom_scm_dt_match, NULL, NULL);

 	of_node_put(fw_np);

 	if (ret)
 		return ret;

 	return platform_driver_register(&qcom_scm_driver);
 }
 subsys_initcall(qcom_scm_init);
	/*
	* Qualcomm SCM driver
	*
	* Copyright (c) 2010,2015, The Linux Foundation. All rights reserved.
	* Copyright (C) 2015 Linaro Ltd.
	*
	* 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/platform_device.h>
	#include <linux/init.h>
	#include <linux/cpumask.h>
	#include <linux/export.h>
	#include <linux/dma-mapping.h>
	#include <linux/types.h>
	#include <linux/qcom_scm.h>
	#include <linux/of.h>
	#include <linux/of_platform.h>
	#include <linux/clk.h>
	#include <linux/reset-controller.h>

	#include "qcom_scm.h"

	#define SCM_HAS_CORE_CLK BIT(0)
	#define SCM_HAS_IFACE_CLK BIT(1)
	#define SCM_HAS_BUS_CLK BIT(2)

	struct qcom_scm {
	struct device *dev;
	struct clk *core_clk;
	struct clk *iface_clk;
	struct clk *bus_clk;
	struct reset_controller_dev reset;
	};

	static struct qcom_scm *__scm;

	static int qcom_scm_clk_enable(void)
	{
	int ret;

	ret = clk_prepare_enable(__scm->core_clk);
	if (ret)
	goto bail;

	ret = clk_prepare_enable(__scm->iface_clk);
	if (ret)
	goto disable_core;

	ret = clk_prepare_enable(__scm->bus_clk);
	if (ret)
	goto disable_iface;

	return 0;

	disable_iface:
	clk_disable_unprepare(__scm->iface_clk);
	disable_core:
	clk_disable_unprepare(__scm->core_clk);
	bail:
	return ret;
	}

	static void qcom_scm_clk_disable(void)
	{
	clk_disable_unprepare(__scm->core_clk);
	clk_disable_unprepare(__scm->iface_clk);
	clk_disable_unprepare(__scm->bus_clk);
	}

	/**
	* qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
	* @entry: Entry point function for the cpus
	* @cpus: The cpumask of cpus that will use the entry point
	*
	* Set the cold boot address of the cpus. Any cpu outside the supported
	* range would be removed from the cpu present mask.
	*/
	int qcom_scm_set_cold_boot_addr(void entry, const cpumask_t cpus)
	{
	return __qcom_scm_set_cold_boot_addr(entry, cpus);
	}
	EXPORT_SYMBOL(qcom_scm_set_cold_boot_addr);

	/**
	* qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus
	* @entry: Entry point function for the cpus
	* @cpus: The cpumask of cpus that will use the entry point
	*
	* Set the Linux entry point for the SCM to transfer control to when coming
	* out of a power down. CPU power down may be executed on cpuidle or hotplug.
	*/
	int qcom_scm_set_warm_boot_addr(void entry, const cpumask_t cpus)
	{
	return __qcom_scm_set_warm_boot_addr(__scm->dev, entry, cpus);
	}
	EXPORT_SYMBOL(qcom_scm_set_warm_boot_addr);

	/**
	* qcom_scm_cpu_power_down() - Power down the cpu
	* @flags - Flags to flush cache
	*
	* This is an end point to power down cpu. If there was a pending interrupt,
	* the control would return from this function, otherwise, the cpu jumps to the
	* warm boot entry point set for this cpu upon reset.
	*/
	void qcom_scm_cpu_power_down(u32 flags)
	{
	__qcom_scm_cpu_power_down(flags);
	}
	EXPORT_SYMBOL(qcom_scm_cpu_power_down);

	/**
	* qcom_scm_hdcp_available() - Check if secure environment supports HDCP.
	*
	* Return true if HDCP is supported, false if not.
	*/
	bool qcom_scm_hdcp_available(void)
	{
	int ret = qcom_scm_clk_enable();

	if (ret)
	return ret;

	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_HDCP,
	QCOM_SCM_CMD_HDCP);

	qcom_scm_clk_disable();

	return ret > 0 ? true : false;
	}
	EXPORT_SYMBOL(qcom_scm_hdcp_available);

	/**
	* qcom_scm_hdcp_req() - Send HDCP request.
	* @req: HDCP request array
	* @req_cnt: HDCP request array count
	* @resp: response buffer passed to SCM
	*
	* Write HDCP register(s) through SCM.
	*/
	int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req req, u32 req_cnt, u32 resp)
	{
	int ret = qcom_scm_clk_enable();

	if (ret)
	return ret;

	ret = __qcom_scm_hdcp_req(__scm->dev, req, req_cnt, resp);
	qcom_scm_clk_disable();
	return ret;
	}
	EXPORT_SYMBOL(qcom_scm_hdcp_req);

	/**
	* qcom_scm_pas_supported() - Check if the peripheral authentication service is
	* available for the given peripherial
	* @peripheral: peripheral id
	*
	* Returns true if PAS is supported for this peripheral, otherwise false.
	*/
	bool qcom_scm_pas_supported(u32 peripheral)
	{
	int ret;

	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_PIL,
	QCOM_SCM_PAS_IS_SUPPORTED_CMD);
	if (ret <= 0)
	return false;

	return __qcom_scm_pas_supported(__scm->dev, peripheral);
	}
	EXPORT_SYMBOL(qcom_scm_pas_supported);

	/**
	* qcom_scm_pas_init_image() - Initialize peripheral authentication service
	* state machine for a given peripheral, using the
	* metadata
	* @peripheral: peripheral id
	* @metadata: pointer to memory containing ELF header, program header table
	* and optional blob of data used for authenticating the metadata
	* and the rest of the firmware
	* @size: size of the metadata
	*
	* Returns 0 on success.
	*/
	int qcom_scm_pas_init_image(u32 peripheral, const void *metadata, size_t size)
	{
	dma_addr_t mdata_phys;
	void *mdata_buf;
	int ret;

	/*
	* During the scm call memory protection will be enabled for the meta
	* data blob, so make sure it's physically contiguous, 4K aligned and
	* non-cachable to avoid XPU violations.
	*/
	mdata_buf = dma_alloc_coherent(__scm->dev, size, &mdata_phys,
	GFP_KERNEL);
	if (!mdata_buf) {
	dev_err(__scm->dev, "Allocation of metadata buffer failed.\n");
	return -ENOMEM;
	}
	memcpy(mdata_buf, metadata, size);

	ret = qcom_scm_clk_enable();
	if (ret)
	goto free_metadata;

	ret = __qcom_scm_pas_init_image(__scm->dev, peripheral, mdata_phys);

	qcom_scm_clk_disable();

	free_metadata:
	dma_free_coherent(__scm->dev, size, mdata_buf, mdata_phys);

	return ret;
	}
	EXPORT_SYMBOL(qcom_scm_pas_init_image);

	/**
	* qcom_scm_pas_mem_setup() - Prepare the memory related to a given peripheral
	* for firmware loading
	* @peripheral: peripheral id
	* @addr: start address of memory area to prepare
	* @size: size of the memory area to prepare
	*
	* Returns 0 on success.
	*/
	int qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size)
	{
	int ret;

	ret = qcom_scm_clk_enable();
	if (ret)
	return ret;

	ret = __qcom_scm_pas_mem_setup(__scm->dev, peripheral, addr, size);
	qcom_scm_clk_disable();

	return ret;
	}
	EXPORT_SYMBOL(qcom_scm_pas_mem_setup);

	/**
	* qcom_scm_pas_auth_and_reset() - Authenticate the given peripheral firmware
	* and reset the remote processor
	* @peripheral: peripheral id
	*
	* Return 0 on success.
	*/
	int qcom_scm_pas_auth_and_reset(u32 peripheral)
	{
	int ret;

	ret = qcom_scm_clk_enable();
	if (ret)
	return ret;

	ret = __qcom_scm_pas_auth_and_reset(__scm->dev, peripheral);
	qcom_scm_clk_disable();

	return ret;
	}
	EXPORT_SYMBOL(qcom_scm_pas_auth_and_reset);

	/**
	* qcom_scm_pas_shutdown() - Shut down the remote processor
	* @peripheral: peripheral id
	*
	* Returns 0 on success.
	*/
	int qcom_scm_pas_shutdown(u32 peripheral)
	{
	int ret;

	ret = qcom_scm_clk_enable();
	if (ret)
	return ret;

	ret = __qcom_scm_pas_shutdown(__scm->dev, peripheral);
	qcom_scm_clk_disable();

	return ret;
	}
	EXPORT_SYMBOL(qcom_scm_pas_shutdown);

	static int qcom_scm_pas_reset_assert(struct reset_controller_dev *rcdev,
	unsigned long idx)
	{
	if (idx != 0)
	return -EINVAL;

	return __qcom_scm_pas_mss_reset(__scm->dev, 1);
	}

	static int qcom_scm_pas_reset_deassert(struct reset_controller_dev *rcdev,
	unsigned long idx)
	{
	if (idx != 0)
	return -EINVAL;

	return __qcom_scm_pas_mss_reset(__scm->dev, 0);
	}

	static const struct reset_control_ops qcom_scm_pas_reset_ops = {
	.assert = qcom_scm_pas_reset_assert,
	.deassert = qcom_scm_pas_reset_deassert,
	};

	/**
	* qcom_scm_is_available() - Checks if SCM is available
	*/
	bool qcom_scm_is_available(void)
	{
	return !!__scm;
	}
	EXPORT_SYMBOL(qcom_scm_is_available);

	int qcom_scm_set_remote_state(u32 state, u32 id)
	{
	return __qcom_scm_set_remote_state(__scm->dev, state, id);
	}
	EXPORT_SYMBOL(qcom_scm_set_remote_state);

	static int qcom_scm_probe(struct platform_device *pdev)
	{
	struct qcom_scm *scm;
	unsigned long clks;
	int ret;

	scm = devm_kzalloc(&pdev->dev, sizeof(*scm), GFP_KERNEL);
	if (!scm)
	return -ENOMEM;

	clks = (unsigned long)of_device_get_match_data(&pdev->dev);
	if (clks & SCM_HAS_CORE_CLK) {
	scm->core_clk = devm_clk_get(&pdev->dev, "core");
	if (IS_ERR(scm->core_clk)) {
	if (PTR_ERR(scm->core_clk) != -EPROBE_DEFER)
	dev_err(&pdev->dev,
	"failed to acquire core clk\n");
	return PTR_ERR(scm->core_clk);
	}
	}

	if (clks & SCM_HAS_IFACE_CLK) {
	scm->iface_clk = devm_clk_get(&pdev->dev, "iface");
	if (IS_ERR(scm->iface_clk)) {
	if (PTR_ERR(scm->iface_clk) != -EPROBE_DEFER)
	dev_err(&pdev->dev,
	"failed to acquire iface clk\n");
	return PTR_ERR(scm->iface_clk);
	}
	}

	if (clks & SCM_HAS_BUS_CLK) {
	scm->bus_clk = devm_clk_get(&pdev->dev, "bus");
	if (IS_ERR(scm->bus_clk)) {
	if (PTR_ERR(scm->bus_clk) != -EPROBE_DEFER)
	dev_err(&pdev->dev,
	"failed to acquire bus clk\n");
	return PTR_ERR(scm->bus_clk);
	}
	}

	scm->reset.ops = &qcom_scm_pas_reset_ops;
	scm->reset.nr_resets = 1;
	scm->reset.of_node = pdev->dev.of_node;
	ret = devm_reset_controller_register(&pdev->dev, &scm->reset);
	if (ret)
	return ret;

	/* vote for max clk rate for highest performance */
	ret = clk_set_rate(scm->core_clk, INT_MAX);
	if (ret)
	return ret;

	__scm = scm;
	__scm->dev = &pdev->dev;

	__qcom_scm_init();

	return 0;
	}

	static const struct of_device_id qcom_scm_dt_match[] = {
	{ .compatible = "qcom,scm-apq8064",
	/* FIXME: This should have .data = (void ) SCM_HAS_CORE_CLK /
	},
	{ .compatible = "qcom,scm-msm8660",
	.data = (void *) SCM_HAS_CORE_CLK,
	},
	{ .compatible = "qcom,scm-msm8960",
	.data = (void *) SCM_HAS_CORE_CLK,
	},
	{ .compatible = "qcom,scm-msm8996",
	.data = NULL, /* no clocks */
	},
	{ .compatible = "qcom,scm",
	.data = (void *)(SCM_HAS_CORE_CLK
	\| SCM_HAS_IFACE_CLK
	\| SCM_HAS_BUS_CLK),
	},
	{}
	};

	static struct platform_driver qcom_scm_driver = {
	.driver = {
	.name = "qcom_scm",
	.of_match_table = qcom_scm_dt_match,
	},
	.probe = qcom_scm_probe,
	};

	static int __init qcom_scm_init(void)
	{
	struct device_node np, fw_np;
	int ret;

	fw_np = of_find_node_by_name(NULL, "firmware");

	if (!fw_np)
	return -ENODEV;

	np = of_find_matching_node(fw_np, qcom_scm_dt_match);

	if (!np) {
	of_node_put(fw_np);
	return -ENODEV;
	}

	of_node_put(np);

	ret = of_platform_populate(fw_np, qcom_scm_dt_match, NULL, NULL);

	of_node_put(fw_np);

	if (ret)
	return ret;

	return platform_driver_register(&qcom_scm_driver);
	}
	subsys_initcall(qcom_scm_init);