drivers/spmi/spmi-pmic-arb-debug.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (c) 2012-2019, 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/clk.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/spmi.h>

 /* PMIC Arbiter debug register offsets */
 #define PMIC_ARB_DEBUG_CMD0		0x00
 #define PMIC_ARB_DEBUG_CMD1		0x04
 #define PMIC_ARB_DEBUG_CMD2		0x08
 #define PMIC_ARB_DEBUG_CMD3		0x0C
 #define PMIC_ARB_DEBUG_STATUS		0x14
 #define PMIC_ARB_DEBUG_WDATA(n)		(0x18 + 4 * (n))
 #define PMIC_ARB_DEBUG_RDATA(n)		(0x38 + 4 * (n))

 /* Transaction status flag bits */
 enum pmic_arb_chnl_status {
 	PMIC_ARB_STATUS_DONE		= BIT(0),
 	PMIC_ARB_STATUS_FAILURE		= BIT(1),
 	PMIC_ARB_STATUS_DENIED		= BIT(2),
 	PMIC_ARB_STATUS_DROPPED		= BIT(3),
 };

 /* Command Opcodes */
 enum pmic_arb_cmd_op_code {
 	PMIC_ARB_OP_EXT_WRITEL		= 0,
 	PMIC_ARB_OP_EXT_READL		= 1,
 	PMIC_ARB_OP_EXT_WRITE		= 2,
 	PMIC_ARB_OP_RESET		= 3,
 	PMIC_ARB_OP_SLEEP		= 4,
 	PMIC_ARB_OP_SHUTDOWN		= 5,
 	PMIC_ARB_OP_WAKEUP		= 6,
 	PMIC_ARB_OP_AUTHENTICATE	= 7,
 	PMIC_ARB_OP_MSTR_READ		= 8,
 	PMIC_ARB_OP_MSTR_WRITE		= 9,
 	PMIC_ARB_OP_EXT_READ		= 13,
 	PMIC_ARB_OP_WRITE		= 14,
 	PMIC_ARB_OP_READ		= 15,
 	PMIC_ARB_OP_ZERO_WRITE		= 16,
 };

 #define PMIC_ARB_TIMEOUT_US		100
 #define PMIC_ARB_MAX_TRANS_BYTES	8
 #define PMIC_ARB_MAX_SID		0xF

 /**
  * spmi_pmic_arb_debug - SPMI PMIC Arbiter debug object
  *
  * @addr:		base address of SPMI PMIC arbiter debug module
  * @lock:		lock to synchronize accesses.
  */
 struct spmi_pmic_arb_debug {
 	void __iomem		*addr;
 	raw_spinlock_t		lock;
 	struct clk		*clock;
 };

 static inline void pmic_arb_debug_write(struct spmi_pmic_arb_debug *pa,
 				u32 offset, u32 val)
 {
 	writel_relaxed(val, pa->addr + offset);
 }

 static inline u32 pmic_arb_debug_read(struct spmi_pmic_arb_debug *pa,
 				u32 offset)
 {
 	return readl_relaxed(pa->addr + offset);
 }

 /* pa->lock must be held by the caller. */
 static int pmic_arb_debug_wait_for_done(struct spmi_controller *ctrl)
 {
 	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
 	u32 status = 0;
 	u32 timeout = PMIC_ARB_TIMEOUT_US;

 	while (timeout--) {
 		status = pmic_arb_debug_read(pa, PMIC_ARB_DEBUG_STATUS);

 		if (status & PMIC_ARB_STATUS_DONE) {
 			if (status & PMIC_ARB_STATUS_DENIED) {
 				dev_err(&ctrl->dev, "%s: transaction denied (0x%x)\n",
 					__func__, status);
 				return -EPERM;
 			}

 			if (status & PMIC_ARB_STATUS_FAILURE) {
 				dev_err(&ctrl->dev, "%s: transaction failed (0x%x)\n",
 					__func__, status);
 				return -EIO;
 			}

 			if (status & PMIC_ARB_STATUS_DROPPED) {
 				dev_err(&ctrl->dev, "%s: transaction dropped (0x%x)\n",
 					__func__, status);
 				return -EIO;
 			}

 			return 0;
 		}
 		udelay(1);
 	}

 	dev_err(&ctrl->dev, "%s: timeout, status 0x%x\n", __func__, status);
 	return -ETIMEDOUT;
 }

 /* pa->lock must be held by the caller. */
 static int pmic_arb_debug_issue_command(struct spmi_controller *ctrl, u8 opc,
 				u8 sid, u16 addr, size_t len)
 {
 	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
 	u16 pid       = (addr >> 8) & 0xFF;
 	u16 offset    = addr & 0xFF;
 	u8 byte_count = len - 1;

 	if (byte_count >= PMIC_ARB_MAX_TRANS_BYTES) {
 		dev_err(&ctrl->dev, "pmic-arb supports 1 to %d bytes per transaction, but %zu requested",
 			PMIC_ARB_MAX_TRANS_BYTES, len);
 		return  -EINVAL;
 	}

 	if (sid > PMIC_ARB_MAX_SID) {
 		dev_err(&ctrl->dev, "pmic-arb supports sid 0 to %u, but %u requested",
 			PMIC_ARB_MAX_SID, sid);
 		return  -EINVAL;
 	}

 	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD3, offset);
 	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD2, pid);
 	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD1, (byte_count << 4) | sid);

 	/* Start the transaction */
 	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD0, opc << 1);

 	return pmic_arb_debug_wait_for_done(ctrl);
 }

 /* Non-data command */
 static int pmic_arb_debug_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid)
 {
 	dev_dbg(&ctrl->dev, "cmd op:0x%x sid:%d\n", opc, sid);

 	/* Check for valid non-data command */
 	if (opc < SPMI_CMD_RESET || opc > SPMI_CMD_WAKEUP)
 		return -EINVAL;

 	return -EOPNOTSUPP;
 }

 static int pmic_arb_debug_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
 				u16 addr, u8 *buf, size_t len)
 {
 	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
 	unsigned long flags;
 	int i, rc;

 	/* Check the opcode */
 	if (opc >= 0x60 && opc <= 0x7F)
 		opc = PMIC_ARB_OP_READ;
 	else if (opc >= 0x20 && opc <= 0x2F)
 		opc = PMIC_ARB_OP_EXT_READ;
 	else if (opc >= 0x38 && opc <= 0x3F)
 		opc = PMIC_ARB_OP_EXT_READL;
 	else
 		return -EINVAL;

 	rc = clk_prepare_enable(pa->clock);
 	if (rc) {
 		pr_err("%s: failed to enable core clock, rc=%d\n",
 			__func__, rc);
 		return rc;
 	}
 	raw_spin_lock_irqsave(&pa->lock, flags);

 	rc = pmic_arb_debug_issue_command(ctrl, opc, sid, addr, len);
 	if (rc)
 		goto done;

 	/* Read data from FIFO */
 	for (i = 0; i < len; i++)
 		buf[i] = pmic_arb_debug_read(pa, PMIC_ARB_DEBUG_RDATA(i));
 done:
 	raw_spin_unlock_irqrestore(&pa->lock, flags);
 	clk_disable_unprepare(pa->clock);

 	return rc;
 }

 static int pmic_arb_debug_write_cmd(struct spmi_controller *ctrl, u8 opc,
 				u8 sid, u16 addr, const u8 *buf, size_t len)
 {
 	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
 	unsigned long flags;
 	int i, rc;

 	if (len > PMIC_ARB_MAX_TRANS_BYTES) {
 		dev_err(&ctrl->dev, "pmic-arb supports 1 to %d bytes per transaction, but %zu requested",
 			PMIC_ARB_MAX_TRANS_BYTES, len);
 		return  -EINVAL;
 	}

 	/* Check the opcode */
 	if (opc >= 0x40 && opc <= 0x5F)
 		opc = PMIC_ARB_OP_WRITE;
 	else if (opc >= 0x00 && opc <= 0x0F)
 		opc = PMIC_ARB_OP_EXT_WRITE;
 	else if (opc >= 0x30 && opc <= 0x37)
 		opc = PMIC_ARB_OP_EXT_WRITEL;
 	else if (opc >= 0x80)
 		opc = PMIC_ARB_OP_ZERO_WRITE;
 	else
 		return -EINVAL;

 	rc = clk_prepare_enable(pa->clock);
 	if (rc) {
 		pr_err("%s: failed to enable core clock, rc=%d\n",
 			__func__, rc);
 		return rc;
 	}
 	raw_spin_lock_irqsave(&pa->lock, flags);

 	/* Write data to FIFO */
 	for (i = 0; i < len; i++)
 		pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_WDATA(i), buf[i]);

 	rc = pmic_arb_debug_issue_command(ctrl, opc, sid, addr, len);

 	raw_spin_unlock_irqrestore(&pa->lock, flags);
 	clk_disable_unprepare(pa->clock);

 	return rc;
 }

 static int spmi_pmic_arb_debug_probe(struct platform_device *pdev)
 {
 	struct spmi_pmic_arb_debug *pa;
 	struct spmi_controller *ctrl;
 	struct resource *res;
 	int rc;
 	u32 fuse_val, fuse_bit;
 	void __iomem *fuse_addr;

 	/* Check if the debug bus is disabled by a fuse. */
 	rc = of_property_read_u32(pdev->dev.of_node, "qcom,fuse-disable-bit",
 				  &fuse_bit);
 	if (!rc) {
 		if (fuse_bit > 31) {
 			dev_err(&pdev->dev, "qcom,fuse-disable-bit supports values 0 to 31, but %u specified\n",
 				fuse_bit);
 			return -EINVAL;
 		}

 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 						   "fuse");
 		if (!res) {
 			dev_err(&pdev->dev, "fuse address not specified\n");
 			return -EINVAL;
 		}

 		fuse_addr = devm_ioremap_resource(&pdev->dev, res);
 		if (IS_ERR(fuse_addr))
 			return PTR_ERR(fuse_addr);

 		fuse_val = readl_relaxed(fuse_addr);
 		devm_iounmap(&pdev->dev, fuse_addr);

 		if (fuse_val & BIT(fuse_bit)) {
 			dev_err(&pdev->dev, "SPMI PMIC arbiter debug bus disabled by fuse\n");
 			return -ENODEV;
 		}
 	}


 	ctrl = spmi_controller_alloc(&pdev->dev, sizeof(*pa));
 	if (!ctrl)
 		return -ENOMEM;

 	pa = spmi_controller_get_drvdata(ctrl);

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "core");
 	if (!res) {
 		dev_err(&pdev->dev, "core address not specified\n");
 		rc = -EINVAL;
 		goto err_put_ctrl;
 	}

 	pa->addr = devm_ioremap_resource(&ctrl->dev, res);
 	if (IS_ERR(pa->addr)) {
 		rc = PTR_ERR(pa->addr);
 		goto err_put_ctrl;
 	}

 	if (of_find_property(pdev->dev.of_node, "clock-names", NULL)) {
 		pa->clock = devm_clk_get(&pdev->dev, "core_clk");
 		if (IS_ERR(pa->clock)) {
 			rc = PTR_ERR(pa->clock);
 			if (rc != -EPROBE_DEFER)
 				dev_err(&pdev->dev, "unable to request core clock, rc=%d\n",
 					rc);
 			goto err_put_ctrl;
 		}
 	}

 	platform_set_drvdata(pdev, ctrl);
 	raw_spin_lock_init(&pa->lock);

 	ctrl->cmd = pmic_arb_debug_cmd;
 	ctrl->read_cmd = pmic_arb_debug_read_cmd;
 	ctrl->write_cmd = pmic_arb_debug_write_cmd;

 	rc = spmi_controller_add(ctrl);
 	if (rc)
 		goto err_put_ctrl;

 	dev_info(&ctrl->dev, "SPMI PMIC arbiter debug bus controller added\n");

 	return 0;

 err_put_ctrl:
 	spmi_controller_put(ctrl);
 	return rc;
 }

 static int spmi_pmic_arb_debug_remove(struct platform_device *pdev)
 {
 	struct spmi_controller *ctrl = platform_get_drvdata(pdev);

 	spmi_controller_remove(ctrl);
 	spmi_controller_put(ctrl);

 	return 0;
 }

 static const struct of_device_id spmi_pmic_arb_debug_match_table[] = {
 	{ .compatible = "qcom,spmi-pmic-arb-debug", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, spmi_pmic_arb_debug_match_table);

 static struct platform_driver spmi_pmic_arb_debug_driver = {
 	.probe		= spmi_pmic_arb_debug_probe,
 	.remove		= spmi_pmic_arb_debug_remove,
 	.driver		= {
 		.name	= "spmi_pmic_arb_debug",
 		.of_match_table = spmi_pmic_arb_debug_match_table,
 	},
 };

 module_platform_driver(spmi_pmic_arb_debug_driver);

 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:spmi_pmic_arb_debug");
	/*
	* Copyright (c) 2012-2019, 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/clk.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/spmi.h>

	/* PMIC Arbiter debug register offsets */
	#define PMIC_ARB_DEBUG_CMD0 0x00
	#define PMIC_ARB_DEBUG_CMD1 0x04
	#define PMIC_ARB_DEBUG_CMD2 0x08
	#define PMIC_ARB_DEBUG_CMD3 0x0C
	#define PMIC_ARB_DEBUG_STATUS 0x14
	#define PMIC_ARB_DEBUG_WDATA(n) (0x18 + 4 * (n))
	#define PMIC_ARB_DEBUG_RDATA(n) (0x38 + 4 * (n))

	/* Transaction status flag bits */
	enum pmic_arb_chnl_status {
	PMIC_ARB_STATUS_DONE = BIT(0),
	PMIC_ARB_STATUS_FAILURE = BIT(1),
	PMIC_ARB_STATUS_DENIED = BIT(2),
	PMIC_ARB_STATUS_DROPPED = BIT(3),
	};

	/* Command Opcodes */
	enum pmic_arb_cmd_op_code {
	PMIC_ARB_OP_EXT_WRITEL = 0,
	PMIC_ARB_OP_EXT_READL = 1,
	PMIC_ARB_OP_EXT_WRITE = 2,
	PMIC_ARB_OP_RESET = 3,
	PMIC_ARB_OP_SLEEP = 4,
	PMIC_ARB_OP_SHUTDOWN = 5,
	PMIC_ARB_OP_WAKEUP = 6,
	PMIC_ARB_OP_AUTHENTICATE = 7,
	PMIC_ARB_OP_MSTR_READ = 8,
	PMIC_ARB_OP_MSTR_WRITE = 9,
	PMIC_ARB_OP_EXT_READ = 13,
	PMIC_ARB_OP_WRITE = 14,
	PMIC_ARB_OP_READ = 15,
	PMIC_ARB_OP_ZERO_WRITE = 16,
	};

	#define PMIC_ARB_TIMEOUT_US 100
	#define PMIC_ARB_MAX_TRANS_BYTES 8
	#define PMIC_ARB_MAX_SID 0xF

	/**
	* spmi_pmic_arb_debug - SPMI PMIC Arbiter debug object
	*
	* @addr: base address of SPMI PMIC arbiter debug module
	* @lock: lock to synchronize accesses.
	*/
	struct spmi_pmic_arb_debug {
	void __iomem *addr;
	raw_spinlock_t lock;
	struct clk *clock;
	};

	static inline void pmic_arb_debug_write(struct spmi_pmic_arb_debug *pa,
	u32 offset, u32 val)
	{
	writel_relaxed(val, pa->addr + offset);
	}

	static inline u32 pmic_arb_debug_read(struct spmi_pmic_arb_debug *pa,
	u32 offset)
	{
	return readl_relaxed(pa->addr + offset);
	}

	/* pa->lock must be held by the caller. */
	static int pmic_arb_debug_wait_for_done(struct spmi_controller *ctrl)
	{
	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
	u32 status = 0;
	u32 timeout = PMIC_ARB_TIMEOUT_US;

	while (timeout--) {
	status = pmic_arb_debug_read(pa, PMIC_ARB_DEBUG_STATUS);

	if (status & PMIC_ARB_STATUS_DONE) {
	if (status & PMIC_ARB_STATUS_DENIED) {
	dev_err(&ctrl->dev, "%s: transaction denied (0x%x)\n",
	__func__, status);
	return -EPERM;
	}

	if (status & PMIC_ARB_STATUS_FAILURE) {
	dev_err(&ctrl->dev, "%s: transaction failed (0x%x)\n",
	__func__, status);
	return -EIO;
	}

	if (status & PMIC_ARB_STATUS_DROPPED) {
	dev_err(&ctrl->dev, "%s: transaction dropped (0x%x)\n",
	__func__, status);
	return -EIO;
	}

	return 0;
	}
	udelay(1);
	}

	dev_err(&ctrl->dev, "%s: timeout, status 0x%x\n", __func__, status);
	return -ETIMEDOUT;
	}

	/* pa->lock must be held by the caller. */
	static int pmic_arb_debug_issue_command(struct spmi_controller *ctrl, u8 opc,
	u8 sid, u16 addr, size_t len)
	{
	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
	u16 pid = (addr >> 8) & 0xFF;
	u16 offset = addr & 0xFF;
	u8 byte_count = len - 1;

	if (byte_count >= PMIC_ARB_MAX_TRANS_BYTES) {
	dev_err(&ctrl->dev, "pmic-arb supports 1 to %d bytes per transaction, but %zu requested",
	PMIC_ARB_MAX_TRANS_BYTES, len);
	return -EINVAL;
	}

	if (sid > PMIC_ARB_MAX_SID) {
	dev_err(&ctrl->dev, "pmic-arb supports sid 0 to %u, but %u requested",
	PMIC_ARB_MAX_SID, sid);
	return -EINVAL;
	}

	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD3, offset);
	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD2, pid);
	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD1, (byte_count << 4) \| sid);

	/* Start the transaction */
	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_CMD0, opc << 1);

	return pmic_arb_debug_wait_for_done(ctrl);
	}

	/* Non-data command */
	static int pmic_arb_debug_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid)
	{
	dev_dbg(&ctrl->dev, "cmd op:0x%x sid:%d\n", opc, sid);

	/* Check for valid non-data command */
	if (opc < SPMI_CMD_RESET \|\| opc > SPMI_CMD_WAKEUP)
	return -EINVAL;

	return -EOPNOTSUPP;
	}

	static int pmic_arb_debug_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
	u16 addr, u8 *buf, size_t len)
	{
	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
	unsigned long flags;
	int i, rc;

	/* Check the opcode */
	if (opc >= 0x60 && opc <= 0x7F)
	opc = PMIC_ARB_OP_READ;
	else if (opc >= 0x20 && opc <= 0x2F)
	opc = PMIC_ARB_OP_EXT_READ;
	else if (opc >= 0x38 && opc <= 0x3F)
	opc = PMIC_ARB_OP_EXT_READL;
	else
	return -EINVAL;

	rc = clk_prepare_enable(pa->clock);
	if (rc) {
	pr_err("%s: failed to enable core clock, rc=%d\n",
	__func__, rc);
	return rc;
	}
	raw_spin_lock_irqsave(&pa->lock, flags);

	rc = pmic_arb_debug_issue_command(ctrl, opc, sid, addr, len);
	if (rc)
	goto done;

	/* Read data from FIFO */
	for (i = 0; i < len; i++)
	buf[i] = pmic_arb_debug_read(pa, PMIC_ARB_DEBUG_RDATA(i));
	done:
	raw_spin_unlock_irqrestore(&pa->lock, flags);
	clk_disable_unprepare(pa->clock);

	return rc;
	}

	static int pmic_arb_debug_write_cmd(struct spmi_controller *ctrl, u8 opc,
	u8 sid, u16 addr, const u8 *buf, size_t len)
	{
	struct spmi_pmic_arb_debug *pa = spmi_controller_get_drvdata(ctrl);
	unsigned long flags;
	int i, rc;

	if (len > PMIC_ARB_MAX_TRANS_BYTES) {
	dev_err(&ctrl->dev, "pmic-arb supports 1 to %d bytes per transaction, but %zu requested",
	PMIC_ARB_MAX_TRANS_BYTES, len);
	return -EINVAL;
	}

	/* Check the opcode */
	if (opc >= 0x40 && opc <= 0x5F)
	opc = PMIC_ARB_OP_WRITE;
	else if (opc >= 0x00 && opc <= 0x0F)
	opc = PMIC_ARB_OP_EXT_WRITE;
	else if (opc >= 0x30 && opc <= 0x37)
	opc = PMIC_ARB_OP_EXT_WRITEL;
	else if (opc >= 0x80)
	opc = PMIC_ARB_OP_ZERO_WRITE;
	else
	return -EINVAL;

	rc = clk_prepare_enable(pa->clock);
	if (rc) {
	pr_err("%s: failed to enable core clock, rc=%d\n",
	__func__, rc);
	return rc;
	}
	raw_spin_lock_irqsave(&pa->lock, flags);

	/* Write data to FIFO */
	for (i = 0; i < len; i++)
	pmic_arb_debug_write(pa, PMIC_ARB_DEBUG_WDATA(i), buf[i]);

	rc = pmic_arb_debug_issue_command(ctrl, opc, sid, addr, len);

	raw_spin_unlock_irqrestore(&pa->lock, flags);
	clk_disable_unprepare(pa->clock);

	return rc;
	}

	static int spmi_pmic_arb_debug_probe(struct platform_device *pdev)
	{
	struct spmi_pmic_arb_debug *pa;
	struct spmi_controller *ctrl;
	struct resource *res;
	int rc;
	u32 fuse_val, fuse_bit;
	void __iomem *fuse_addr;

	/* Check if the debug bus is disabled by a fuse. */
	rc = of_property_read_u32(pdev->dev.of_node, "qcom,fuse-disable-bit",
	&fuse_bit);
	if (!rc) {
	if (fuse_bit > 31) {
	dev_err(&pdev->dev, "qcom,fuse-disable-bit supports values 0 to 31, but %u specified\n",
	fuse_bit);
	return -EINVAL;
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
	"fuse");
	if (!res) {
	dev_err(&pdev->dev, "fuse address not specified\n");
	return -EINVAL;
	}

	fuse_addr = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(fuse_addr))
	return PTR_ERR(fuse_addr);

	fuse_val = readl_relaxed(fuse_addr);
	devm_iounmap(&pdev->dev, fuse_addr);

	if (fuse_val & BIT(fuse_bit)) {
	dev_err(&pdev->dev, "SPMI PMIC arbiter debug bus disabled by fuse\n");
	return -ENODEV;
	}
	}


	ctrl = spmi_controller_alloc(&pdev->dev, sizeof(*pa));
	if (!ctrl)
	return -ENOMEM;

	pa = spmi_controller_get_drvdata(ctrl);

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "core");
	if (!res) {
	dev_err(&pdev->dev, "core address not specified\n");
	rc = -EINVAL;
	goto err_put_ctrl;
	}

	pa->addr = devm_ioremap_resource(&ctrl->dev, res);
	if (IS_ERR(pa->addr)) {
	rc = PTR_ERR(pa->addr);
	goto err_put_ctrl;
	}

	if (of_find_property(pdev->dev.of_node, "clock-names", NULL)) {
	pa->clock = devm_clk_get(&pdev->dev, "core_clk");
	if (IS_ERR(pa->clock)) {
	rc = PTR_ERR(pa->clock);
	if (rc != -EPROBE_DEFER)
	dev_err(&pdev->dev, "unable to request core clock, rc=%d\n",
	rc);
	goto err_put_ctrl;
	}
	}

	platform_set_drvdata(pdev, ctrl);
	raw_spin_lock_init(&pa->lock);

	ctrl->cmd = pmic_arb_debug_cmd;
	ctrl->read_cmd = pmic_arb_debug_read_cmd;
	ctrl->write_cmd = pmic_arb_debug_write_cmd;

	rc = spmi_controller_add(ctrl);
	if (rc)
	goto err_put_ctrl;

	dev_info(&ctrl->dev, "SPMI PMIC arbiter debug bus controller added\n");

	return 0;

	err_put_ctrl:
	spmi_controller_put(ctrl);
	return rc;
	}

	static int spmi_pmic_arb_debug_remove(struct platform_device *pdev)
	{
	struct spmi_controller *ctrl = platform_get_drvdata(pdev);

	spmi_controller_remove(ctrl);
	spmi_controller_put(ctrl);

	return 0;
	}

	static const struct of_device_id spmi_pmic_arb_debug_match_table[] = {
	{ .compatible = "qcom,spmi-pmic-arb-debug", },
	{},
	};
	MODULE_DEVICE_TABLE(of, spmi_pmic_arb_debug_match_table);

	static struct platform_driver spmi_pmic_arb_debug_driver = {
	.probe = spmi_pmic_arb_debug_probe,
	.remove = spmi_pmic_arb_debug_remove,
	.driver = {
	.name = "spmi_pmic_arb_debug",
	.of_match_table = spmi_pmic_arb_debug_match_table,
	},
	};

	module_platform_driver(spmi_pmic_arb_debug_driver);

	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:spmi_pmic_arb_debug");