drivers/spmi/spmi-pmic-arb.c

/* Copyright (c) 2012-2013, 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/delay.h>
#include <linux/err.h>
#include <linux/interrupt.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 configuration registers */
#define PMIC_ARB_VERSION		0x0000
#define PMIC_ARB_INT_EN			0x0004

/* PMIC Arbiter channel registers */
#define PMIC_ARB_CMD(N)			(0x0800 + (0x80 * (N)))
#define PMIC_ARB_CONFIG(N)		(0x0804 + (0x80 * (N)))
#define PMIC_ARB_STATUS(N)		(0x0808 + (0x80 * (N)))
#define PMIC_ARB_WDATA0(N)		(0x0810 + (0x80 * (N)))
#define PMIC_ARB_WDATA1(N)		(0x0814 + (0x80 * (N)))
#define PMIC_ARB_RDATA0(N)		(0x0818 + (0x80 * (N)))
#define PMIC_ARB_RDATA1(N)		(0x081C + (0x80 * (N)))

/* Interrupt Controller */
#define SPMI_PIC_OWNER_ACC_STATUS(M, N)	(0x0000 + ((32 * (M)) + (4 * (N))))
#define SPMI_PIC_ACC_ENABLE(N)		(0x0200 + (4 * (N)))
#define SPMI_PIC_IRQ_STATUS(N)		(0x0600 + (4 * (N)))
#define SPMI_PIC_IRQ_CLEAR(N)		(0x0A00 + (4 * (N)))

/* Mapping Table */
#define SPMI_MAPPING_TABLE_REG(N)	(0x0B00 + (4 * (N)))
#define SPMI_MAPPING_BIT_INDEX(X)	(((X) >> 18) & 0xF)
#define SPMI_MAPPING_BIT_IS_0_FLAG(X)	(((X) >> 17) & 0x1)
#define SPMI_MAPPING_BIT_IS_0_RESULT(X)	(((X) >> 9) & 0xFF)
#define SPMI_MAPPING_BIT_IS_1_FLAG(X)	(((X) >> 8) & 0x1)
#define SPMI_MAPPING_BIT_IS_1_RESULT(X)	(((X) >> 0) & 0xFF)

#define SPMI_MAPPING_TABLE_LEN		255
#define SPMI_MAPPING_TABLE_TREE_DEPTH	16	/* Maximum of 16-bits */

/* Ownership Table */
#define SPMI_OWNERSHIP_TABLE_REG(N)	(0x0700 + (4 * (N)))
#define SPMI_OWNERSHIP_PERIPH2OWNER(X)	((X) & 0x7)

/* Channel Status fields */
enum pmic_arb_chnl_status {
	PMIC_ARB_STATUS_DONE	= (1 << 0),
	PMIC_ARB_STATUS_FAILURE	= (1 << 1),
	PMIC_ARB_STATUS_DENIED	= (1 << 2),
	PMIC_ARB_STATUS_DROPPED	= (1 << 3),
};

/* Command register fields */
#define PMIC_ARB_CMD_MAX_BYTE_COUNT	8

/* 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,
};

/* Maximum number of support PMIC peripherals */
#define PMIC_ARB_MAX_PERIPHS		256
#define PMIC_ARB_PERIPH_ID_VALID	(1 << 15)
#define PMIC_ARB_TIMEOUT_US		100
#define PMIC_ARB_MAX_TRANS_BYTES	(8)

#define PMIC_ARB_APID_MASK		0xFF
#define PMIC_ARB_PPID_MASK		0xFFF

/* interrupt enable bit */
#define SPMI_PIC_ACC_ENABLE_BIT		BIT(0)

/**
 * spmi_pmic_arb_dev - SPMI PMIC Arbiter object
 *
 * @base:		address of the PMIC Arbiter core registers.
 * @intr:		address of the SPMI interrupt control registers.
 * @cnfg:		address of the PMIC Arbiter configuration registers.
 * @lock:		lock to synchronize accesses.
 * @channel:		which channel to use for accesses.
 */
struct spmi_pmic_arb_dev {
	void __iomem		*base;
	void __iomem		*intr;
	void __iomem		*cnfg;
	raw_spinlock_t		lock;
	u8			channel;
};

static inline u32 pmic_arb_base_read(struct spmi_pmic_arb_dev *dev, u32 offset)
{
	return readl_relaxed(dev->base + offset);
}

static inline void pmic_arb_base_write(struct spmi_pmic_arb_dev *dev,
				       u32 offset, u32 val)
{
	writel_relaxed(val, dev->base + offset);
}

/**
 * pa_read_data: reads pmic-arb's register and copy 1..4 bytes to buf
 * @bc:		byte count -1. range: 0..3
 * @reg:	register's address
 * @buf:	output parameter, length must be bc + 1
 */
static void pa_read_data(struct spmi_pmic_arb_dev *dev, u8 *buf, u32 reg, u8 bc)
{
	u32 data = pmic_arb_base_read(dev, reg);
	memcpy(buf, &data, (bc & 3) + 1);
}

/**
 * pa_write_data: write 1..4 bytes from buf to pmic-arb's register
 * @bc:		byte-count -1. range: 0..3.
 * @reg:	register's address.
 * @buf:	buffer to write. length must be bc + 1.
 */
static void
pa_write_data(struct spmi_pmic_arb_dev *dev, const u8 *buf, u32 reg, u8 bc)
{
	u32 data = 0;
	memcpy(&data, buf, (bc & 3) + 1);
	pmic_arb_base_write(dev, reg, data);
}

static int pmic_arb_wait_for_done(struct spmi_controller *ctrl)
{
	struct spmi_pmic_arb_dev *dev = spmi_controller_get_drvdata(ctrl);
	u32 status = 0;
	u32 timeout = PMIC_ARB_TIMEOUT_US;
	u32 offset = PMIC_ARB_STATUS(dev->channel);

	while (timeout--) {
		status = pmic_arb_base_read(dev, offset);

		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;
}

/* Non-data command */
static int pmic_arb_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid)
{
	struct spmi_pmic_arb_dev *pmic_arb = spmi_controller_get_drvdata(ctrl);
	unsigned long flags;
	u32 cmd;
	int rc;

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

	cmd = ((opc | 0x40) << 27) | ((sid & 0xf) << 20);

	raw_spin_lock_irqsave(&pmic_arb->lock, flags);
	pmic_arb_base_write(pmic_arb, PMIC_ARB_CMD(pmic_arb->channel), cmd);
	rc = pmic_arb_wait_for_done(ctrl);
	raw_spin_unlock_irqrestore(&pmic_arb->lock, flags);

	return rc;
}

static int pmic_arb_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
			     u16 addr, u8 *buf, size_t len)
{
	struct spmi_pmic_arb_dev *pmic_arb = spmi_controller_get_drvdata(ctrl);
	unsigned long flags;
	u8 bc = len - 1;
	u32 cmd;
	int rc;

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

	/* 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;

	cmd = (opc << 27) | ((sid & 0xf) << 20) | (addr << 4) | (bc & 0x7);

	raw_spin_lock_irqsave(&pmic_arb->lock, flags);
	pmic_arb_base_write(pmic_arb, PMIC_ARB_CMD(pmic_arb->channel), cmd);
	rc = pmic_arb_wait_for_done(ctrl);
	if (rc)
		goto done;

	pa_read_data(pmic_arb, buf, PMIC_ARB_RDATA0(pmic_arb->channel),
		     min_t(u8, bc, 3));

	if (bc > 3)
		pa_read_data(pmic_arb, buf + 4,
				PMIC_ARB_RDATA1(pmic_arb->channel), bc - 4);

done:
	raw_spin_unlock_irqrestore(&pmic_arb->lock, flags);
	return rc;
}

static int pmic_arb_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
			      u16 addr, const u8 *buf, size_t len)
{
	struct spmi_pmic_arb_dev *pmic_arb = spmi_controller_get_drvdata(ctrl);
	unsigned long flags;
	u8 bc = len - 1;
	u32 cmd;
	int rc;

	if (bc >= PMIC_ARB_MAX_TRANS_BYTES) {
		dev_err(&ctrl->dev,
			"pmic-arb supports 1..%d bytes per trans, but:%d 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 <= 0xFF)
		opc = PMIC_ARB_OP_ZERO_WRITE;
	else
		return -EINVAL;

	cmd = (opc << 27) | ((sid & 0xf) << 20) | (addr << 4) | (bc & 0x7);

	/* Write data to FIFOs */
	raw_spin_lock_irqsave(&pmic_arb->lock, flags);
	pa_write_data(pmic_arb, buf, PMIC_ARB_WDATA0(pmic_arb->channel)
							, min_t(u8, bc, 3));
	if (bc > 3)
		pa_write_data(pmic_arb, buf + 4,
				PMIC_ARB_WDATA1(pmic_arb->channel), bc - 4);

	/* Start the transaction */
	pmic_arb_base_write(pmic_arb, PMIC_ARB_CMD(pmic_arb->channel), cmd);
	rc = pmic_arb_wait_for_done(ctrl);
	raw_spin_unlock_irqrestore(&pmic_arb->lock, flags);

	return rc;
}

static int spmi_pmic_arb_probe(struct platform_device *pdev)
{
	struct spmi_pmic_arb_dev *pa;
	struct spmi_controller *ctrl;
	struct resource *res;
	u32 channel;
	int err, i;

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

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "intr");
	pa->intr = devm_ioremap_resource(&ctrl->dev, res);
	if (IS_ERR(pa->intr)) {
		err = PTR_ERR(pa->intr);
		goto err_put_ctrl;
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cnfg");
	pa->cnfg = devm_ioremap_resource(&ctrl->dev, res);
	if (IS_ERR(pa->cnfg)) {
		err = PTR_ERR(pa->cnfg);
		goto err_put_ctrl;
	}

	err = of_property_read_u32(pdev->dev.of_node, "qcom,channel", &channel);
	if (err) {
		dev_err(&pdev->dev, "channel unspecified.\n");
		goto err_put_ctrl;
	}

	if (channel > 5) {
		dev_err(&pdev->dev, "invalid channel (%u) specified.\n",
			channel);
		goto err_put_ctrl;
	}

	pa->channel = channel;

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

	ctrl->cmd = pmic_arb_cmd;
	ctrl->read_cmd = pmic_arb_read_cmd;
	ctrl->write_cmd = pmic_arb_write_cmd;

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

	dev_dbg(&ctrl->dev, "PMIC Arb Version 0x%x\n",
		pmic_arb_base_read(pa, PMIC_ARB_VERSION));

	return 0;

err_put_ctrl:
	spmi_controller_put(ctrl);
	return err;
}

static int spmi_pmic_arb_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_match_table[] = {
	{ .compatible = "qcom,spmi-pmic-arb", },
	{},
};
MODULE_DEVICE_TABLE(of, spmi_pmic_arb_match_table);

static struct platform_driver spmi_pmic_arb_driver = {
	.probe		= spmi_pmic_arb_probe,
	.remove		= spmi_pmic_arb_remove,
	.driver		= {
		.name	= "spmi_pmic_arb",
		.owner	= THIS_MODULE,
		.of_match_table = spmi_pmic_arb_match_table,
	},
};
module_platform_driver(spmi_pmic_arb_driver);

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