drivers/soc/qcom/ramp_controller.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Qualcomm Ramp Controller driver
  * Copyright (c) 2022, AngeloGioacchino Del Regno
  *                     <angelogioacchino.delregno@collabora.com>
  */

 #include <linux/bitfield.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/types.h>

 #define RC_UPDATE_EN		BIT(0)
 #define RC_ROOT_EN		BIT(1)

 #define RC_REG_CFG_UPDATE	0x60
 #define RC_CFG_UPDATE_EN	BIT(8)
 #define RC_CFG_ACK		GENMASK(31, 16)

 #define RC_DCVS_CFG_SID		2
 #define RC_LINK_SID		3
 #define RC_LMH_SID		6
 #define RC_DFS_SID		14

 #define RC_UPDATE_TIMEOUT_US	500

 /**
  * struct qcom_ramp_controller_desc - SoC specific parameters
  * @cfg_dfs_sid:      Dynamic Frequency Scaling SID configuration
  * @cfg_link_sid:     Link SID configuration
  * @cfg_lmh_sid:      Limits Management hardware SID configuration
  * @cfg_ramp_en:      Ramp Controller enable sequence
  * @cfg_ramp_dis:     Ramp Controller disable sequence
  * @cmd_reg:          Command register offset
  * @num_dfs_sids:     Number of DFS SIDs (max 8)
  * @num_link_sids:    Number of Link SIDs (max 3)
  * @num_lmh_sids:     Number of LMh SIDs (max 8)
  * @num_ramp_en:      Number of entries in enable sequence
  * @num_ramp_dis:     Number of entries in disable sequence
  */
 struct qcom_ramp_controller_desc {
 	const struct reg_sequence *cfg_dfs_sid;
 	const struct reg_sequence *cfg_link_sid;
 	const struct reg_sequence *cfg_lmh_sid;
 	const struct reg_sequence *cfg_ramp_en;
 	const struct reg_sequence *cfg_ramp_dis;
 	u8 cmd_reg;
 	u8 num_dfs_sids;
 	u8 num_link_sids;
 	u8 num_lmh_sids;
 	u8 num_ramp_en;
 	u8 num_ramp_dis;
 };

 /**
  * struct qcom_ramp_controller - Main driver structure
  * @regmap: Regmap handle
  * @desc:   SoC specific parameters
  */
 struct qcom_ramp_controller {
 	struct regmap *regmap;
 	const struct qcom_ramp_controller_desc *desc;
 };

 /**
  * rc_wait_for_update() - Wait for Ramp Controller root update
  * @qrc: Main driver structure
  *
  * Return: Zero for success or negative number for failure
  */
 static int rc_wait_for_update(struct qcom_ramp_controller *qrc)
 {
 	const struct qcom_ramp_controller_desc *d = qrc->desc;
 	struct regmap *r = qrc->regmap;
 	u32 val;
 	int ret;

 	ret = regmap_set_bits(r, d->cmd_reg, RC_ROOT_EN);
 	if (ret)
 		return ret;

 	return regmap_read_poll_timeout(r, d->cmd_reg, val, !(val & RC_UPDATE_EN),
 					1, RC_UPDATE_TIMEOUT_US);
 }

 /**
  * rc_set_cfg_update() - Ramp Controller configuration update
  * @qrc: Main driver structure
  * @ce: Configuration entry to update
  *
  * Return: Zero for success or negative number for failure
  */
 static int rc_set_cfg_update(struct qcom_ramp_controller *qrc, u8 ce)
 {
 	const struct qcom_ramp_controller_desc *d = qrc->desc;
 	struct regmap *r = qrc->regmap;
 	u32 ack, val;
 	int ret;

 	/* The ack bit is between bits 16-31 of RC_REG_CFG_UPDATE */
 	ack = FIELD_PREP(RC_CFG_ACK, BIT(ce));

 	/* Write the configuration type first... */
 	ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, ce);
 	if (ret)
 		return ret;

 	/* ...and after that, enable the update bit to sync the changes */
 	ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, RC_CFG_UPDATE_EN);
 	if (ret)
 		return ret;

 	/* Wait for the changes to go through */
 	ret = regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE, val,
 				       val & ack, 1, RC_UPDATE_TIMEOUT_US);
 	if (ret)
 		return ret;

 	/*
 	 * Configuration update success! The CFG_UPDATE register will not be
 	 * cleared automatically upon applying the configuration, so we have
 	 * to do that manually in order to leave the ramp controller in a
 	 * predictable and clean state.
 	 */
 	ret = regmap_write(r, d->cmd_reg + RC_REG_CFG_UPDATE, 0);
 	if (ret)
 		return ret;

 	/* Wait for the update bit cleared ack */
 	return regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE,
 					val, !(val & RC_CFG_ACK), 1,
 					RC_UPDATE_TIMEOUT_US);
 }

 /**
  * rc_write_cfg - Send configuration sequence
  * @qrc: Main driver structure
  * @seq: Register sequence to send before asking for update
  * @ce: Configuration SID
  * @nsids: Total number of SIDs
  *
  * Returns: Zero for success or negative number for error
  */
 static int rc_write_cfg(struct qcom_ramp_controller *qrc,
 			const struct reg_sequence *seq,
 			u16 ce, u8 nsids)
 {
 	int ret;
 	u8 i;

 	/* Check if, and wait until the ramp controller is ready */
 	ret = rc_wait_for_update(qrc);
 	if (ret)
 		return ret;

 	/* Write the sequence */
 	ret = regmap_multi_reg_write(qrc->regmap, seq, nsids);
 	if (ret)
 		return ret;

 	/* Pull the trigger: do config update starting from the last sid */
 	for (i = 0; i < nsids; i++) {
 		ret = rc_set_cfg_update(qrc, (u8)ce - i);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 /**
  * rc_ramp_ctrl_enable() - Enable Ramp up/down Control
  * @qrc: Main driver structure
  *
  * Return: Zero for success or negative number for error
  */
 static int rc_ramp_ctrl_enable(struct qcom_ramp_controller *qrc)
 {
 	const struct qcom_ramp_controller_desc *d = qrc->desc;
 	int i, ret;

 	for (i = 0; i < d->num_ramp_en; i++) {
 		ret = rc_write_cfg(qrc, &d->cfg_ramp_en[i], RC_DCVS_CFG_SID, 1);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }

 /**
  * qcom_ramp_controller_start() - Initialize and start the ramp controller
  * @qrc: Main driver structure
  *
  * The Ramp Controller needs to be initialized by programming the relevant
  * registers with SoC-specific configuration: once programming is done,
  * the hardware will take care of the rest (no further handling required).
  *
  * Return: Zero for success or negative number for error
  */
 static int qcom_ramp_controller_start(struct qcom_ramp_controller *qrc)
 {
 	const struct qcom_ramp_controller_desc *d = qrc->desc;
 	int ret;

 	/* Program LMH, DFS, Link SIDs */
 	ret = rc_write_cfg(qrc, d->cfg_lmh_sid, RC_LMH_SID, d->num_lmh_sids);
 	if (ret)
 		return ret;

 	ret = rc_write_cfg(qrc, d->cfg_dfs_sid, RC_DFS_SID, d->num_dfs_sids);
 	if (ret)
 		return ret;

 	ret = rc_write_cfg(qrc, d->cfg_link_sid, RC_LINK_SID, d->num_link_sids);
 	if (ret)
 		return ret;

 	/* Everything is ready! Enable the ramp up/down control */
 	return rc_ramp_ctrl_enable(qrc);
 }

 static const struct regmap_config qrc_regmap_config = {
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,
 	.max_register =	0x68,
 	.fast_io = true,
 };

 static const struct reg_sequence msm8976_cfg_dfs_sid[] = {
 	{ 0x10, 0xfefebff7 },
 	{ 0x14, 0xfdff7fef },
 	{ 0x18, 0xfbffdefb },
 	{ 0x1c, 0xb69b5555 },
 	{ 0x20, 0x24929249 },
 	{ 0x24, 0x49241112 },
 	{ 0x28, 0x11112111 },
 	{ 0x2c, 0x8102 }
 };

 static const struct reg_sequence msm8976_cfg_link_sid[] = {
 	{ 0x40, 0xfc987 }
 };

 static const struct reg_sequence msm8976_cfg_lmh_sid[] = {
 	{ 0x30, 0x77706db },
 	{ 0x34, 0x5550249 },
 	{ 0x38, 0x111 }
 };

 static const struct reg_sequence msm8976_cfg_ramp_en[] = {
 	{ 0x50, 0x800 }, /* pre_en */
 	{ 0x50, 0xc00 }, /* en */
 	{ 0x50, 0x400 }  /* post_en */
 };

 static const struct reg_sequence msm8976_cfg_ramp_dis[] = {
 	{ 0x50, 0x0 }
 };

 static const struct qcom_ramp_controller_desc msm8976_rc_cfg = {
 	.cfg_dfs_sid = msm8976_cfg_dfs_sid,
 	.num_dfs_sids = ARRAY_SIZE(msm8976_cfg_dfs_sid),

 	.cfg_link_sid = msm8976_cfg_link_sid,
 	.num_link_sids = ARRAY_SIZE(msm8976_cfg_link_sid),

 	.cfg_lmh_sid = msm8976_cfg_lmh_sid,
 	.num_lmh_sids = ARRAY_SIZE(msm8976_cfg_lmh_sid),

 	.cfg_ramp_en = msm8976_cfg_ramp_en,
 	.num_ramp_en = ARRAY_SIZE(msm8976_cfg_ramp_en),

 	.cfg_ramp_dis = msm8976_cfg_ramp_dis,
 	.num_ramp_dis = ARRAY_SIZE(msm8976_cfg_ramp_dis),

 	.cmd_reg = 0x0,
 };

 static int qcom_ramp_controller_probe(struct platform_device *pdev)
 {
 	struct qcom_ramp_controller *qrc;
 	void __iomem *base;

 	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base))
 		return PTR_ERR(base);

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

 	qrc->desc = device_get_match_data(&pdev->dev);
 	if (!qrc->desc)
 		return -EINVAL;

 	qrc->regmap = devm_regmap_init_mmio(&pdev->dev, base, &qrc_regmap_config);
 	if (IS_ERR(qrc->regmap))
 		return PTR_ERR(qrc->regmap);

 	platform_set_drvdata(pdev, qrc);

 	return qcom_ramp_controller_start(qrc);
 }

 static void qcom_ramp_controller_remove(struct platform_device *pdev)
 {
 	struct qcom_ramp_controller *qrc = platform_get_drvdata(pdev);
 	int ret;

 	ret = rc_write_cfg(qrc, qrc->desc->cfg_ramp_dis,
 			   RC_DCVS_CFG_SID, qrc->desc->num_ramp_dis);
 	if (ret)
 		dev_err(&pdev->dev, "Failed to send disable sequence\n");
 }

 static const struct of_device_id qcom_ramp_controller_match_table[] = {
 	{ .compatible = "qcom,msm8976-ramp-controller", .data = &msm8976_rc_cfg },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, qcom_ramp_controller_match_table);

 static struct platform_driver qcom_ramp_controller_driver = {
 	.driver = {
 		.name = "qcom-ramp-controller",
 		.of_match_table = qcom_ramp_controller_match_table,
 		.suppress_bind_attrs = true,
 	},
 	.probe  = qcom_ramp_controller_probe,
 	.remove_new = qcom_ramp_controller_remove,
 };

 static int __init qcom_ramp_controller_init(void)
 {
 	return platform_driver_register(&qcom_ramp_controller_driver);
 }
 arch_initcall(qcom_ramp_controller_init);

 MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
 MODULE_DESCRIPTION("Qualcomm Ramp Controller driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Qualcomm Ramp Controller driver
	* Copyright (c) 2022, AngeloGioacchino Del Regno
	* <angelogioacchino.delregno@collabora.com>
	*/

	#include <linux/bitfield.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_platform.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/types.h>

	#define RC_UPDATE_EN BIT(0)
	#define RC_ROOT_EN BIT(1)

	#define RC_REG_CFG_UPDATE 0x60
	#define RC_CFG_UPDATE_EN BIT(8)
	#define RC_CFG_ACK GENMASK(31, 16)

	#define RC_DCVS_CFG_SID 2
	#define RC_LINK_SID 3
	#define RC_LMH_SID 6
	#define RC_DFS_SID 14

	#define RC_UPDATE_TIMEOUT_US 500

	/**
	* struct qcom_ramp_controller_desc - SoC specific parameters
	* @cfg_dfs_sid: Dynamic Frequency Scaling SID configuration
	* @cfg_link_sid: Link SID configuration
	* @cfg_lmh_sid: Limits Management hardware SID configuration
	* @cfg_ramp_en: Ramp Controller enable sequence
	* @cfg_ramp_dis: Ramp Controller disable sequence
	* @cmd_reg: Command register offset
	* @num_dfs_sids: Number of DFS SIDs (max 8)
	* @num_link_sids: Number of Link SIDs (max 3)
	* @num_lmh_sids: Number of LMh SIDs (max 8)
	* @num_ramp_en: Number of entries in enable sequence
	* @num_ramp_dis: Number of entries in disable sequence
	*/
	struct qcom_ramp_controller_desc {
	const struct reg_sequence *cfg_dfs_sid;
	const struct reg_sequence *cfg_link_sid;
	const struct reg_sequence *cfg_lmh_sid;
	const struct reg_sequence *cfg_ramp_en;
	const struct reg_sequence *cfg_ramp_dis;
	u8 cmd_reg;
	u8 num_dfs_sids;
	u8 num_link_sids;
	u8 num_lmh_sids;
	u8 num_ramp_en;
	u8 num_ramp_dis;
	};

	/**
	* struct qcom_ramp_controller - Main driver structure
	* @regmap: Regmap handle
	* @desc: SoC specific parameters
	*/
	struct qcom_ramp_controller {
	struct regmap *regmap;
	const struct qcom_ramp_controller_desc *desc;
	};

	/**
	* rc_wait_for_update() - Wait for Ramp Controller root update
	* @qrc: Main driver structure
	*
	* Return: Zero for success or negative number for failure
	*/
	static int rc_wait_for_update(struct qcom_ramp_controller *qrc)
	{
	const struct qcom_ramp_controller_desc *d = qrc->desc;
	struct regmap *r = qrc->regmap;
	u32 val;
	int ret;

	ret = regmap_set_bits(r, d->cmd_reg, RC_ROOT_EN);
	if (ret)
	return ret;

	return regmap_read_poll_timeout(r, d->cmd_reg, val, !(val & RC_UPDATE_EN),
	1, RC_UPDATE_TIMEOUT_US);
	}

	/**
	* rc_set_cfg_update() - Ramp Controller configuration update
	* @qrc: Main driver structure
	* @ce: Configuration entry to update
	*
	* Return: Zero for success or negative number for failure
	*/
	static int rc_set_cfg_update(struct qcom_ramp_controller *qrc, u8 ce)
	{
	const struct qcom_ramp_controller_desc *d = qrc->desc;
	struct regmap *r = qrc->regmap;
	u32 ack, val;
	int ret;

	/* The ack bit is between bits 16-31 of RC_REG_CFG_UPDATE */
	ack = FIELD_PREP(RC_CFG_ACK, BIT(ce));

	/* Write the configuration type first... */
	ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, ce);
	if (ret)
	return ret;

	/* ...and after that, enable the update bit to sync the changes */
	ret = regmap_set_bits(r, d->cmd_reg + RC_REG_CFG_UPDATE, RC_CFG_UPDATE_EN);
	if (ret)
	return ret;

	/* Wait for the changes to go through */
	ret = regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE, val,
	val & ack, 1, RC_UPDATE_TIMEOUT_US);
	if (ret)
	return ret;

	/*
	* Configuration update success! The CFG_UPDATE register will not be
	* cleared automatically upon applying the configuration, so we have
	* to do that manually in order to leave the ramp controller in a
	* predictable and clean state.
	*/
	ret = regmap_write(r, d->cmd_reg + RC_REG_CFG_UPDATE, 0);
	if (ret)
	return ret;

	/* Wait for the update bit cleared ack */
	return regmap_read_poll_timeout(r, d->cmd_reg + RC_REG_CFG_UPDATE,
	val, !(val & RC_CFG_ACK), 1,
	RC_UPDATE_TIMEOUT_US);
	}

	/**
	* rc_write_cfg - Send configuration sequence
	* @qrc: Main driver structure
	* @seq: Register sequence to send before asking for update
	* @ce: Configuration SID
	* @nsids: Total number of SIDs
	*
	* Returns: Zero for success or negative number for error
	*/
	static int rc_write_cfg(struct qcom_ramp_controller *qrc,
	const struct reg_sequence *seq,
	u16 ce, u8 nsids)
	{
	int ret;
	u8 i;

	/* Check if, and wait until the ramp controller is ready */
	ret = rc_wait_for_update(qrc);
	if (ret)
	return ret;

	/* Write the sequence */
	ret = regmap_multi_reg_write(qrc->regmap, seq, nsids);
	if (ret)
	return ret;

	/* Pull the trigger: do config update starting from the last sid */
	for (i = 0; i < nsids; i++) {
	ret = rc_set_cfg_update(qrc, (u8)ce - i);
	if (ret)
	return ret;
	}

	return 0;
	}

	/**
	* rc_ramp_ctrl_enable() - Enable Ramp up/down Control
	* @qrc: Main driver structure
	*
	* Return: Zero for success or negative number for error
	*/
	static int rc_ramp_ctrl_enable(struct qcom_ramp_controller *qrc)
	{
	const struct qcom_ramp_controller_desc *d = qrc->desc;
	int i, ret;

	for (i = 0; i < d->num_ramp_en; i++) {
	ret = rc_write_cfg(qrc, &d->cfg_ramp_en[i], RC_DCVS_CFG_SID, 1);
	if (ret)
	return ret;
	}

	return 0;
	}

	/**
	* qcom_ramp_controller_start() - Initialize and start the ramp controller
	* @qrc: Main driver structure
	*
	* The Ramp Controller needs to be initialized by programming the relevant
	* registers with SoC-specific configuration: once programming is done,
	* the hardware will take care of the rest (no further handling required).
	*
	* Return: Zero for success or negative number for error
	*/
	static int qcom_ramp_controller_start(struct qcom_ramp_controller *qrc)
	{
	const struct qcom_ramp_controller_desc *d = qrc->desc;
	int ret;

	/* Program LMH, DFS, Link SIDs */
	ret = rc_write_cfg(qrc, d->cfg_lmh_sid, RC_LMH_SID, d->num_lmh_sids);
	if (ret)
	return ret;

	ret = rc_write_cfg(qrc, d->cfg_dfs_sid, RC_DFS_SID, d->num_dfs_sids);
	if (ret)
	return ret;

	ret = rc_write_cfg(qrc, d->cfg_link_sid, RC_LINK_SID, d->num_link_sids);
	if (ret)
	return ret;

	/* Everything is ready! Enable the ramp up/down control */
	return rc_ramp_ctrl_enable(qrc);
	}

	static const struct regmap_config qrc_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.max_register = 0x68,
	.fast_io = true,
	};

	static const struct reg_sequence msm8976_cfg_dfs_sid[] = {
	{ 0x10, 0xfefebff7 },
	{ 0x14, 0xfdff7fef },
	{ 0x18, 0xfbffdefb },
	{ 0x1c, 0xb69b5555 },
	{ 0x20, 0x24929249 },
	{ 0x24, 0x49241112 },
	{ 0x28, 0x11112111 },
	{ 0x2c, 0x8102 }
	};

	static const struct reg_sequence msm8976_cfg_link_sid[] = {
	{ 0x40, 0xfc987 }
	};

	static const struct reg_sequence msm8976_cfg_lmh_sid[] = {
	{ 0x30, 0x77706db },
	{ 0x34, 0x5550249 },
	{ 0x38, 0x111 }
	};

	static const struct reg_sequence msm8976_cfg_ramp_en[] = {
	{ 0x50, 0x800 }, /* pre_en */
	{ 0x50, 0xc00 }, /* en */
	{ 0x50, 0x400 } /* post_en */
	};

	static const struct reg_sequence msm8976_cfg_ramp_dis[] = {
	{ 0x50, 0x0 }
	};

	static const struct qcom_ramp_controller_desc msm8976_rc_cfg = {
	.cfg_dfs_sid = msm8976_cfg_dfs_sid,
	.num_dfs_sids = ARRAY_SIZE(msm8976_cfg_dfs_sid),

	.cfg_link_sid = msm8976_cfg_link_sid,
	.num_link_sids = ARRAY_SIZE(msm8976_cfg_link_sid),

	.cfg_lmh_sid = msm8976_cfg_lmh_sid,
	.num_lmh_sids = ARRAY_SIZE(msm8976_cfg_lmh_sid),

	.cfg_ramp_en = msm8976_cfg_ramp_en,
	.num_ramp_en = ARRAY_SIZE(msm8976_cfg_ramp_en),

	.cfg_ramp_dis = msm8976_cfg_ramp_dis,
	.num_ramp_dis = ARRAY_SIZE(msm8976_cfg_ramp_dis),

	.cmd_reg = 0x0,
	};

	static int qcom_ramp_controller_probe(struct platform_device *pdev)
	{
	struct qcom_ramp_controller *qrc;
	void __iomem *base;

	base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(base))
	return PTR_ERR(base);

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

	qrc->desc = device_get_match_data(&pdev->dev);
	if (!qrc->desc)
	return -EINVAL;

	qrc->regmap = devm_regmap_init_mmio(&pdev->dev, base, &qrc_regmap_config);
	if (IS_ERR(qrc->regmap))
	return PTR_ERR(qrc->regmap);

	platform_set_drvdata(pdev, qrc);

	return qcom_ramp_controller_start(qrc);
	}

	static void qcom_ramp_controller_remove(struct platform_device *pdev)
	{
	struct qcom_ramp_controller *qrc = platform_get_drvdata(pdev);
	int ret;

	ret = rc_write_cfg(qrc, qrc->desc->cfg_ramp_dis,
	RC_DCVS_CFG_SID, qrc->desc->num_ramp_dis);
	if (ret)
	dev_err(&pdev->dev, "Failed to send disable sequence\n");
	}

	static const struct of_device_id qcom_ramp_controller_match_table[] = {
	{ .compatible = "qcom,msm8976-ramp-controller", .data = &msm8976_rc_cfg },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, qcom_ramp_controller_match_table);

	static struct platform_driver qcom_ramp_controller_driver = {
	.driver = {
	.name = "qcom-ramp-controller",
	.of_match_table = qcom_ramp_controller_match_table,
	.suppress_bind_attrs = true,
	},
	.probe = qcom_ramp_controller_probe,
	.remove_new = qcom_ramp_controller_remove,
	};

	static int __init qcom_ramp_controller_init(void)
	{
	return platform_driver_register(&qcom_ramp_controller_driver);
	}
	arch_initcall(qcom_ramp_controller_init);

	MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
	MODULE_DESCRIPTION("Qualcomm Ramp Controller driver");
	MODULE_LICENSE("GPL");