drivers/ata/ahci_msm.c - kernel/msm - Git at Google

 /*
  * Copyright (c) 2013, 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/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/err.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
 #include <linux/ahci_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

 struct msm_ahci_clk_info {
 	struct list_head list;
 	struct clk *clk;
 	const char *name;
 	u32 max_freq;
 	bool enabled;
 };

 struct msm_ahci_host {
 	struct platform_device *ahci_pdev;
 	struct list_head clk_list_head;
 	void __iomem *ahci_base;
 	struct phy *phy;
 	bool phy_powered_on;
 };

 static int msm_ahci_enable_clk(struct device *dev,
 		struct msm_ahci_clk_info *clki)
 {
 	int ret = 0;

 	if (clki->enabled)
 		goto out;

 	ret = clk_prepare_enable(clki->clk);
 	if (ret) {
 		dev_err(dev, "%s: %s prepare enable failed, %d\n",
 				__func__, clki->name, ret);
 	} else {
 		clki->enabled = true;
 		dev_dbg(dev, "%s: clk: %s enabled\n",
 				__func__, clki->name);
 	}
 out:
 	return ret;
 }

 static void msm_ahci_disable_clk(struct device *dev,
 		struct msm_ahci_clk_info *clki)
 {
 	if (!clki->enabled)
 		return;

 	clk_disable_unprepare(clki->clk);
 	clki->enabled = false;
 	dev_dbg(dev, "%s: clk: %s disabled\n",
 				__func__, clki->name);
 }

 static int msm_ahci_setup_asic_rbc_clks(struct msm_ahci_host *host, bool on)
 {
 	int ret = 0;
 	struct device *dev = host->ahci_pdev->dev.parent;
 	struct msm_ahci_clk_info *clki;
 	struct list_head *head = &host->clk_list_head;

 	if (!head || list_empty(head))
 		goto out;

 	/*
 	 * asic0_clk and rbc0_clk should be enabled/disabled
 	 * only when PHY is powered on.
 	 */
 	if (!host->phy_powered_on)
 		goto out;

 gate_ungate:
 	list_for_each_entry(clki, head, list) {
 		if (IS_ERR_OR_NULL(clki->clk))
 			continue;

 		if (!strcmp(clki->name, "asic0_clk") ||
 				!strcmp(clki->name, "rbc0_clk")) {
 			if (on)
 				ret = msm_ahci_enable_clk(dev, clki);
 			else
 				msm_ahci_disable_clk(dev, clki);
 		}
 	}
 out:
 	if (ret) {
 		on = false;
 		goto gate_ungate;
 	}

 	return ret;
 }

 static int msm_ahci_setup_clocks(struct msm_ahci_host *host, bool on)
 {
 	int ret = 0;
 	struct device *dev = host->ahci_pdev->dev.parent;
 	struct msm_ahci_clk_info *clki;
 	struct list_head *head = &host->clk_list_head;

 	if (!head || list_empty(head))
 		goto out;

 gate_ungate:
 	list_for_each_entry(clki, head, list) {
 		if (IS_ERR_OR_NULL(clki->clk))
 			continue;

 		/*
 		 * asic0_clk and rbc0_clk are handled separately
 		 * see msm_ahci_setup_asic_rbc_clks().
 		 */
 		if (!strcmp(clki->name, "asic0_clk") ||
 				!strcmp(clki->name, "rbc0_clk"))
 				continue;
 		if (on)
 			ret = msm_ahci_enable_clk(dev, clki);
 		else
 			msm_ahci_disable_clk(dev, clki);
 	}
 out:
 	if (ret) {
 		on = false;
 		goto gate_ungate;
 	}

 	return ret;
 }

 static int msm_ahci_get_clocks(struct msm_ahci_host *host)
 {
 	int ret = 0;
 	struct msm_ahci_clk_info *clki;
 	struct device *dev = host->ahci_pdev->dev.parent;
 	struct list_head *head = &host->clk_list_head;

 	if (!head || list_empty(head))
 		goto out;

 	list_for_each_entry(clki, head, list) {
 		if (!clki->name)
 			continue;

 		clki->clk = devm_clk_get(dev, clki->name);
 		if (IS_ERR(clki->clk)) {
 			ret = PTR_ERR(clki->clk);
 			dev_err(dev, "%s: %s clk get failed, %d\n",
 					__func__, clki->name, ret);
 			goto out;
 		}

 		if (clki->max_freq) {
 			ret = clk_set_rate(clki->clk, clki->max_freq);
 			if (ret) {
 				dev_err(dev, "%s: %s clk set rate(%dHz) failed, %d\n",
 					__func__, clki->name,
 					clki->max_freq, ret);
 				goto out;
 			}
 		}
 		dev_dbg(dev, "%s: clk: %s, rate: %lu\n", __func__,
 				clki->name, clk_get_rate(clki->clk));
 	}
 out:
 	return ret;
 }

 static int msm_ahci_parse_clock_info(struct msm_ahci_host *host)
 {
 	int ret = 0;
 	int cnt;
 	int i;
 	struct device *dev = host->ahci_pdev->dev.parent;
 	struct device_node *np = dev->of_node;
 	char *name;
 	u32 *clkfreq = NULL;
 	struct msm_ahci_clk_info *clki;

 	if (!np)
 		goto out;

 	INIT_LIST_HEAD(&host->clk_list_head);

 	cnt = of_property_count_strings(np, "clock-names");
 	if (!cnt || (cnt == -EINVAL)) {
 		dev_info(dev, "%s: Unable to find clocks, assuming enabled\n",
 				__func__);
 	} else if (cnt < 0) {
 		dev_err(dev, "%s: count clock strings failed, err %d\n",
 				__func__, cnt);
 		ret = cnt;
 	}

 	if (cnt <= 0)
 		goto out;

 	clkfreq = kzalloc(cnt * sizeof(*clkfreq), GFP_KERNEL);
 	if (!clkfreq) {
 		ret = -ENOMEM;
 		dev_err(dev, "%s: memory alloc failed\n", __func__);
 		goto out;
 	}

 	ret = of_property_read_u32_array(np,
 			"max-clock-frequency-hz", clkfreq, cnt);
 	if (ret && (ret != -EINVAL)) {
 		dev_err(dev, "%s: invalid max-clock-frequency-hz property, %d\n",
 				__func__, ret);
 		goto out;
 	}

 	for (i = 0; i < cnt; i++) {
 		ret = of_property_read_string_index(np,
 				"clock-names", i, (const char **)&name);
 		if (ret)
 			goto out;

 		clki = devm_kzalloc(dev, sizeof(*clki), GFP_KERNEL);
 		if (!clki) {
 			ret = -ENOMEM;
 			goto out;
 		}

 		clki->max_freq = clkfreq[i];
 		clki->name = kstrdup(name, GFP_KERNEL);
 		list_add_tail(&clki->list, &host->clk_list_head);
 	}
 out:
 	kfree(clkfreq);
 	return ret;
 }

 static int msm_ahci_init_clocks(struct msm_ahci_host *host)
 {
 	int ret = 0;

 	ret = msm_ahci_parse_clock_info(host);
 	if (ret)
 		goto out;

 	ret = msm_ahci_get_clocks(host);
 	if (ret)
 		goto out;

 	ret = msm_ahci_setup_clocks(host, true);
 	if (ret)
 		goto out;
 out:
 	return ret;
 }

 static void msm_ahci_exit_clocks(struct msm_ahci_host *host)
 {
 	msm_ahci_setup_clocks(host, false);
 }

 static int msm_ahci_init_phy(struct msm_ahci_host *host)
 {
 	int ret = 0;
 	struct device *dev = host->ahci_pdev->dev.parent;

 	host->phy = devm_phy_get(dev, "sata-6g");
 	if (IS_ERR(host->phy)) {
 		ret = PTR_ERR(host->phy);
 		dev_err(dev, "PHY get failed %d\n", ret);
 		goto out;
 	}

 	ret = phy_init(host->phy);
 	if (ret) {
 		dev_err(dev, "PHY initialization failed %d\n", ret);
 		goto out;
 	}

 	ret = phy_power_on(host->phy);
 	if (ret) {
 		dev_err(dev, "PHY power on failed %d\n", ret);
 		goto out;
 	}

 	host->phy_powered_on = true;

 	/* asic0 and rbc0 clks needs to be ungated only after phy power on */
 	ret = msm_ahci_setup_asic_rbc_clks(host, true);
 	if (ret) {
 		dev_err(dev, "failed to enable asic0/rbc0 clks %d", ret);
 		goto out;
 	}

 out:
 	return ret;
 }

 static void msm_ahci_exit_phy(struct msm_ahci_host *host)
 {
 	msm_ahci_setup_asic_rbc_clks(host, false);
 	phy_power_off(host->phy);
 	host->phy_powered_on = false;
 }

 static int msm_ahci_init(struct device *ahci_dev, void __iomem *addr)
 {
 	int ret;
 	struct device *dev = ahci_dev->parent;
 	struct msm_ahci_host *host = dev_get_drvdata(dev);

 	/* Save ahci mmio to access vendor specific registers */
 	host->ahci_base = addr;

 	ret = msm_ahci_init_clocks(host);
 	if (ret) {
 		dev_err(dev, "AHCI clk init failed with err=%d\n", ret);
 		goto out;
 	}

 	ret = msm_ahci_init_phy(host);
 	if (ret) {
 		dev_err(dev, "SATA PHY init failed with err=%d\n", ret);
 		goto out_exit_clks;
 	}

 	return 0;

 out_exit_clks:
 	msm_ahci_exit_clocks(host);
 out:
 	return ret;
 }

 static void msm_ahci_exit(struct device *ahci_dev)
 {
 	struct device *dev = ahci_dev->parent;
 	struct msm_ahci_host *host = dev_get_drvdata(dev);


 	msm_ahci_exit_phy(host);
 	msm_ahci_exit_clocks(host);
 }

 static int msm_ahci_suspend(struct device *ahci_dev)
 {
 	int ret;
 	struct device *dev = ahci_dev->parent;
 	struct msm_ahci_host *host = dev_get_drvdata(dev);

 	msm_ahci_setup_asic_rbc_clks(host, false);
 	ret = phy_power_off(host->phy);
 	if (ret) {
 		dev_err(dev, "%s: PHY power off failed %d\n", __func__, ret);
 		goto out;
 	} else {
 		host->phy_powered_on = false;
 	}

 	msm_ahci_setup_clocks(host, false);
 out:
 	return ret;
 }

 static int msm_ahci_resume(struct device *ahci_dev)
 {
 	int ret;
 	struct device *dev = ahci_dev->parent;
 	struct msm_ahci_host *host = dev_get_drvdata(dev);

 	ret = msm_ahci_setup_clocks(host, true);
 	if (ret)
 		goto out;

 	ret = phy_power_on(host->phy);
 	if (ret) {
 		dev_err(dev, "%s: PHY power on failed %d\n", __func__, ret);
 		goto out;
 	} else {
 		host->phy_powered_on = true;
 	}

 	/* asic0 and rbc0 clks needs to be ungated only after phy power on */
 	ret = msm_ahci_setup_asic_rbc_clks(host, true);
 out:
 	return ret;
 }

 static struct ahci_platform_data msm_ahci_pdata = {
 	.init = msm_ahci_init,
 	.exit = msm_ahci_exit,
 	.suspend = msm_ahci_suspend,
 	.resume = msm_ahci_resume,
 };

 static const struct of_device_id msm_ahci_of_match[] = {
 	{ .compatible = "qcom,msm-ahci", .data = &msm_ahci_pdata },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, msm_ahci_of_match);

 static int msm_ahci_probe(struct platform_device *pdev)
 {
 	int err;
 	struct msm_ahci_host *host;
 	struct device *dev = &pdev->dev;
 	const struct of_device_id *of_id;
 	const struct ahci_platform_data *pdata = NULL;
 	struct platform_device *ahci_pdev;
 	struct device *ahci_dev;
 	int ret = 0;

 	host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
 	if (!host) {
 		dev_err(dev, "failed to allocate memory for msm host\n");
 		ret = -ENOMEM;
 		goto err;
 	}

 	ahci_pdev = platform_device_alloc("ahci", -1);
 	if (!ahci_pdev) {
 		dev_err(dev, "failed to allocate ahci platform device\n");
 		ret = -ENODEV;
 		goto err;
 	}

 	ahci_dev = &ahci_pdev->dev;
 	ahci_dev->parent = dev;

 	if (!dev->dma_mask)
 		dev->dma_mask = &dev->coherent_dma_mask;

 	if (!dma_set_mask(dev, DMA_BIT_MASK(64))) {
 		dma_set_coherent_mask(dev, DMA_BIT_MASK(64));
 	} else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) {
 		dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
 	} else {
 		err = -EIO;
 		dev_err(dev, "unable to set dma mask\n");
 		goto err_put_device;
 	}

 	ahci_dev->dma_mask = dev->dma_mask;
 	ahci_dev->dma_parms = dev->dma_parms;
 	dma_set_coherent_mask(ahci_dev, dev->coherent_dma_mask);

 	host->ahci_pdev = ahci_pdev;

 	platform_set_drvdata(pdev, host);

 	of_id = of_match_device(msm_ahci_of_match, dev);
 	if (of_id) {
 		pdata = of_id->data;
 	} else {
 		ret = -EINVAL;
 		dev_err(dev, "pdata is required to initialze ahci %d\n", ret);
 		goto err;
 	}

 	ahci_dev->of_node = dev->of_node;

 	ret = platform_device_add_resources(ahci_pdev,
 			pdev->resource, pdev->num_resources);
 	if (ret) {
 		dev_err(dev, "failed to add resources %d\n", ret);
 		goto err_put_device;
 	}

 	ret = platform_device_add_data(ahci_pdev, pdata, sizeof(*pdata));
 	if (ret) {
 		dev_err(dev, "failed to add pdata %d\n", ret);
 		goto err_put_device;
 	}

 	ret = platform_device_add(ahci_pdev);
 	if (ret) {
 		dev_err(dev, "failed to register ahci device %d\n", ret);
 		goto err_put_device;
 	}

 	return 0;

 err_put_device:
 	platform_device_put(ahci_pdev);
 err:
 	return ret;
 }

 static int msm_ahci_remove(struct platform_device *pdev)
 {
 	struct msm_ahci_host *host = platform_get_drvdata(pdev);

 	platform_device_unregister(host->ahci_pdev);

 	return 0;
 }

 static struct platform_driver msm_ahci_driver = {
 	.probe		= msm_ahci_probe,
 	.remove		= msm_ahci_remove,
 	.driver		= {
 		.name	= "ahci-msm",
 		.owner = THIS_MODULE,
 		.of_match_table = msm_ahci_of_match,
 	},
 };
 module_platform_driver(msm_ahci_driver);

 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("AHCI platform MSM Glue Layer");
	/*
	* Copyright (c) 2013, 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/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/io.h>
	#include <linux/err.h>
	#include <linux/device.h>
	#include <linux/platform_device.h>
	#include <linux/dma-mapping.h>
	#include <linux/delay.h>
	#include <linux/clk.h>
	#include <linux/ahci_platform.h>
	#include <linux/phy/phy.h>
	#include <linux/of.h>
	#include <linux/of_device.h>

	struct msm_ahci_clk_info {
	struct list_head list;
	struct clk *clk;
	const char *name;
	u32 max_freq;
	bool enabled;
	};

	struct msm_ahci_host {
	struct platform_device *ahci_pdev;
	struct list_head clk_list_head;
	void __iomem *ahci_base;
	struct phy *phy;
	bool phy_powered_on;
	};

	static int msm_ahci_enable_clk(struct device *dev,
	struct msm_ahci_clk_info *clki)
	{
	int ret = 0;

	if (clki->enabled)
	goto out;

	ret = clk_prepare_enable(clki->clk);
	if (ret) {
	dev_err(dev, "%s: %s prepare enable failed, %d\n",
	__func__, clki->name, ret);
	} else {
	clki->enabled = true;
	dev_dbg(dev, "%s: clk: %s enabled\n",
	__func__, clki->name);
	}
	out:
	return ret;
	}

	static void msm_ahci_disable_clk(struct device *dev,
	struct msm_ahci_clk_info *clki)
	{
	if (!clki->enabled)
	return;

	clk_disable_unprepare(clki->clk);
	clki->enabled = false;
	dev_dbg(dev, "%s: clk: %s disabled\n",
	__func__, clki->name);
	}

	static int msm_ahci_setup_asic_rbc_clks(struct msm_ahci_host *host, bool on)
	{
	int ret = 0;
	struct device *dev = host->ahci_pdev->dev.parent;
	struct msm_ahci_clk_info *clki;
	struct list_head *head = &host->clk_list_head;

	if (!head \|\| list_empty(head))
	goto out;

	/*
	* asic0_clk and rbc0_clk should be enabled/disabled
	* only when PHY is powered on.
	*/
	if (!host->phy_powered_on)
	goto out;

	gate_ungate:
	list_for_each_entry(clki, head, list) {
	if (IS_ERR_OR_NULL(clki->clk))
	continue;

	if (!strcmp(clki->name, "asic0_clk") \|\|
	!strcmp(clki->name, "rbc0_clk")) {
	if (on)
	ret = msm_ahci_enable_clk(dev, clki);
	else
	msm_ahci_disable_clk(dev, clki);
	}
	}
	out:
	if (ret) {
	on = false;
	goto gate_ungate;
	}

	return ret;
	}

	static int msm_ahci_setup_clocks(struct msm_ahci_host *host, bool on)
	{
	int ret = 0;
	struct device *dev = host->ahci_pdev->dev.parent;
	struct msm_ahci_clk_info *clki;
	struct list_head *head = &host->clk_list_head;

	if (!head \|\| list_empty(head))
	goto out;

	gate_ungate:
	list_for_each_entry(clki, head, list) {
	if (IS_ERR_OR_NULL(clki->clk))
	continue;

	/*
	* asic0_clk and rbc0_clk are handled separately
	* see msm_ahci_setup_asic_rbc_clks().
	*/
	if (!strcmp(clki->name, "asic0_clk") \|\|
	!strcmp(clki->name, "rbc0_clk"))
	continue;
	if (on)
	ret = msm_ahci_enable_clk(dev, clki);
	else
	msm_ahci_disable_clk(dev, clki);
	}
	out:
	if (ret) {
	on = false;
	goto gate_ungate;
	}

	return ret;
	}

	static int msm_ahci_get_clocks(struct msm_ahci_host *host)
	{
	int ret = 0;
	struct msm_ahci_clk_info *clki;
	struct device *dev = host->ahci_pdev->dev.parent;
	struct list_head *head = &host->clk_list_head;

	if (!head \|\| list_empty(head))
	goto out;

	list_for_each_entry(clki, head, list) {
	if (!clki->name)
	continue;

	clki->clk = devm_clk_get(dev, clki->name);
	if (IS_ERR(clki->clk)) {
	ret = PTR_ERR(clki->clk);
	dev_err(dev, "%s: %s clk get failed, %d\n",
	__func__, clki->name, ret);
	goto out;
	}

	if (clki->max_freq) {
	ret = clk_set_rate(clki->clk, clki->max_freq);
	if (ret) {
	dev_err(dev, "%s: %s clk set rate(%dHz) failed, %d\n",
	__func__, clki->name,
	clki->max_freq, ret);
	goto out;
	}
	}
	dev_dbg(dev, "%s: clk: %s, rate: %lu\n", __func__,
	clki->name, clk_get_rate(clki->clk));
	}
	out:
	return ret;
	}

	static int msm_ahci_parse_clock_info(struct msm_ahci_host *host)
	{
	int ret = 0;
	int cnt;
	int i;
	struct device *dev = host->ahci_pdev->dev.parent;
	struct device_node *np = dev->of_node;
	char *name;
	u32 *clkfreq = NULL;
	struct msm_ahci_clk_info *clki;

	if (!np)
	goto out;

	INIT_LIST_HEAD(&host->clk_list_head);

	cnt = of_property_count_strings(np, "clock-names");
	if (!cnt \|\| (cnt == -EINVAL)) {
	dev_info(dev, "%s: Unable to find clocks, assuming enabled\n",
	__func__);
	} else if (cnt < 0) {
	dev_err(dev, "%s: count clock strings failed, err %d\n",
	__func__, cnt);
	ret = cnt;
	}

	if (cnt <= 0)
	goto out;

	clkfreq = kzalloc(cnt * sizeof(*clkfreq), GFP_KERNEL);
	if (!clkfreq) {
	ret = -ENOMEM;
	dev_err(dev, "%s: memory alloc failed\n", __func__);
	goto out;
	}

	ret = of_property_read_u32_array(np,
	"max-clock-frequency-hz", clkfreq, cnt);
	if (ret && (ret != -EINVAL)) {
	dev_err(dev, "%s: invalid max-clock-frequency-hz property, %d\n",
	__func__, ret);
	goto out;
	}

	for (i = 0; i < cnt; i++) {
	ret = of_property_read_string_index(np,
	"clock-names", i, (const char **)&name);
	if (ret)
	goto out;

	clki = devm_kzalloc(dev, sizeof(*clki), GFP_KERNEL);
	if (!clki) {
	ret = -ENOMEM;
	goto out;
	}

	clki->max_freq = clkfreq[i];
	clki->name = kstrdup(name, GFP_KERNEL);
	list_add_tail(&clki->list, &host->clk_list_head);
	}
	out:
	kfree(clkfreq);
	return ret;
	}

	static int msm_ahci_init_clocks(struct msm_ahci_host *host)
	{
	int ret = 0;

	ret = msm_ahci_parse_clock_info(host);
	if (ret)
	goto out;

	ret = msm_ahci_get_clocks(host);
	if (ret)
	goto out;

	ret = msm_ahci_setup_clocks(host, true);
	if (ret)
	goto out;
	out:
	return ret;
	}

	static void msm_ahci_exit_clocks(struct msm_ahci_host *host)
	{
	msm_ahci_setup_clocks(host, false);
	}

	static int msm_ahci_init_phy(struct msm_ahci_host *host)
	{
	int ret = 0;
	struct device *dev = host->ahci_pdev->dev.parent;

	host->phy = devm_phy_get(dev, "sata-6g");
	if (IS_ERR(host->phy)) {
	ret = PTR_ERR(host->phy);
	dev_err(dev, "PHY get failed %d\n", ret);
	goto out;
	}

	ret = phy_init(host->phy);
	if (ret) {
	dev_err(dev, "PHY initialization failed %d\n", ret);
	goto out;
	}

	ret = phy_power_on(host->phy);
	if (ret) {
	dev_err(dev, "PHY power on failed %d\n", ret);
	goto out;
	}

	host->phy_powered_on = true;

	/* asic0 and rbc0 clks needs to be ungated only after phy power on */
	ret = msm_ahci_setup_asic_rbc_clks(host, true);
	if (ret) {
	dev_err(dev, "failed to enable asic0/rbc0 clks %d", ret);
	goto out;
	}

	out:
	return ret;
	}

	static void msm_ahci_exit_phy(struct msm_ahci_host *host)
	{
	msm_ahci_setup_asic_rbc_clks(host, false);
	phy_power_off(host->phy);
	host->phy_powered_on = false;
	}

	static int msm_ahci_init(struct device ahci_dev, void __iomem addr)
	{
	int ret;
	struct device *dev = ahci_dev->parent;
	struct msm_ahci_host *host = dev_get_drvdata(dev);

	/* Save ahci mmio to access vendor specific registers */
	host->ahci_base = addr;

	ret = msm_ahci_init_clocks(host);
	if (ret) {
	dev_err(dev, "AHCI clk init failed with err=%d\n", ret);
	goto out;
	}

	ret = msm_ahci_init_phy(host);
	if (ret) {
	dev_err(dev, "SATA PHY init failed with err=%d\n", ret);
	goto out_exit_clks;
	}

	return 0;

	out_exit_clks:
	msm_ahci_exit_clocks(host);
	out:
	return ret;
	}

	static void msm_ahci_exit(struct device *ahci_dev)
	{
	struct device *dev = ahci_dev->parent;
	struct msm_ahci_host *host = dev_get_drvdata(dev);


	msm_ahci_exit_phy(host);
	msm_ahci_exit_clocks(host);
	}

	static int msm_ahci_suspend(struct device *ahci_dev)
	{
	int ret;
	struct device *dev = ahci_dev->parent;
	struct msm_ahci_host *host = dev_get_drvdata(dev);

	msm_ahci_setup_asic_rbc_clks(host, false);
	ret = phy_power_off(host->phy);
	if (ret) {
	dev_err(dev, "%s: PHY power off failed %d\n", __func__, ret);
	goto out;
	} else {
	host->phy_powered_on = false;
	}

	msm_ahci_setup_clocks(host, false);
	out:
	return ret;
	}

	static int msm_ahci_resume(struct device *ahci_dev)
	{
	int ret;
	struct device *dev = ahci_dev->parent;
	struct msm_ahci_host *host = dev_get_drvdata(dev);

	ret = msm_ahci_setup_clocks(host, true);
	if (ret)
	goto out;

	ret = phy_power_on(host->phy);
	if (ret) {
	dev_err(dev, "%s: PHY power on failed %d\n", __func__, ret);
	goto out;
	} else {
	host->phy_powered_on = true;
	}

	/* asic0 and rbc0 clks needs to be ungated only after phy power on */
	ret = msm_ahci_setup_asic_rbc_clks(host, true);
	out:
	return ret;
	}

	static struct ahci_platform_data msm_ahci_pdata = {
	.init = msm_ahci_init,
	.exit = msm_ahci_exit,
	.suspend = msm_ahci_suspend,
	.resume = msm_ahci_resume,
	};

	static const struct of_device_id msm_ahci_of_match[] = {
	{ .compatible = "qcom,msm-ahci", .data = &msm_ahci_pdata },
	{ /* sentinel */ },
	};
	MODULE_DEVICE_TABLE(of, msm_ahci_of_match);

	static int msm_ahci_probe(struct platform_device *pdev)
	{
	int err;
	struct msm_ahci_host *host;
	struct device *dev = &pdev->dev;
	const struct of_device_id *of_id;
	const struct ahci_platform_data *pdata = NULL;
	struct platform_device *ahci_pdev;
	struct device *ahci_dev;
	int ret = 0;

	host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
	if (!host) {
	dev_err(dev, "failed to allocate memory for msm host\n");
	ret = -ENOMEM;
	goto err;
	}

	ahci_pdev = platform_device_alloc("ahci", -1);
	if (!ahci_pdev) {
	dev_err(dev, "failed to allocate ahci platform device\n");
	ret = -ENODEV;
	goto err;
	}

	ahci_dev = &ahci_pdev->dev;
	ahci_dev->parent = dev;

	if (!dev->dma_mask)
	dev->dma_mask = &dev->coherent_dma_mask;

	if (!dma_set_mask(dev, DMA_BIT_MASK(64))) {
	dma_set_coherent_mask(dev, DMA_BIT_MASK(64));
	} else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) {
	dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
	} else {
	err = -EIO;
	dev_err(dev, "unable to set dma mask\n");
	goto err_put_device;
	}

	ahci_dev->dma_mask = dev->dma_mask;
	ahci_dev->dma_parms = dev->dma_parms;
	dma_set_coherent_mask(ahci_dev, dev->coherent_dma_mask);

	host->ahci_pdev = ahci_pdev;

	platform_set_drvdata(pdev, host);

	of_id = of_match_device(msm_ahci_of_match, dev);
	if (of_id) {
	pdata = of_id->data;
	} else {
	ret = -EINVAL;
	dev_err(dev, "pdata is required to initialze ahci %d\n", ret);
	goto err;
	}

	ahci_dev->of_node = dev->of_node;

	ret = platform_device_add_resources(ahci_pdev,
	pdev->resource, pdev->num_resources);
	if (ret) {
	dev_err(dev, "failed to add resources %d\n", ret);
	goto err_put_device;
	}

	ret = platform_device_add_data(ahci_pdev, pdata, sizeof(*pdata));
	if (ret) {
	dev_err(dev, "failed to add pdata %d\n", ret);
	goto err_put_device;
	}

	ret = platform_device_add(ahci_pdev);
	if (ret) {
	dev_err(dev, "failed to register ahci device %d\n", ret);
	goto err_put_device;
	}

	return 0;

	err_put_device:
	platform_device_put(ahci_pdev);
	err:
	return ret;
	}

	static int msm_ahci_remove(struct platform_device *pdev)
	{
	struct msm_ahci_host *host = platform_get_drvdata(pdev);

	platform_device_unregister(host->ahci_pdev);

	return 0;
	}

	static struct platform_driver msm_ahci_driver = {
	.probe = msm_ahci_probe,
	.remove = msm_ahci_remove,
	.driver = {
	.name = "ahci-msm",
	.owner = THIS_MODULE,
	.of_match_table = msm_ahci_of_match,
	},
	};
	module_platform_driver(msm_ahci_driver);

	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("AHCI platform MSM Glue Layer");