Release 4.14 drivers/mfd/ssbi.c

Directory: drivers/mfd
/* Copyright (c) 2009-2013, The Linux Foundation. All rights reserved.
 * Copyright (c) 2010, Google Inc.
 *
 * Original authors: Code Aurora Forum
 *
 * Author: Dima Zavin <dima@android.com>
 *  - Largely rewritten from original to not be an i2c driver.
 *
 * 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.
 */


#define pr_fmt(fmt) "%s: " fmt, __func__

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/ssbi.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>

/* SSBI 2.0 controller registers */

#define SSBI2_CMD			0x0008

#define SSBI2_RD			0x0010

#define SSBI2_STATUS			0x0014

#define SSBI2_MODE2			0x001C

/* SSBI_CMD fields */

#define SSBI_CMD_RDWRN			(1 << 24)

/* SSBI_STATUS fields */

#define SSBI_STATUS_RD_READY		(1 << 2)

#define SSBI_STATUS_READY		(1 << 1)

#define SSBI_STATUS_MCHN_BUSY		(1 << 0)

/* SSBI_MODE2 fields */

#define SSBI_MODE2_REG_ADDR_15_8_SHFT	0x04

#define SSBI_MODE2_REG_ADDR_15_8_MASK	(0x7f << SSBI_MODE2_REG_ADDR_15_8_SHFT)


#define SET_SSBI_MODE2_REG_ADDR_15_8(MD, AD) \
	(((MD) & 0x0F) | ((((AD) >> 8) << SSBI_MODE2_REG_ADDR_15_8_SHFT) & \
        SSBI_MODE2_REG_ADDR_15_8_MASK))

/* SSBI PMIC Arbiter command registers */

#define SSBI_PA_CMD			0x0000

#define SSBI_PA_RD_STATUS		0x0004

/* SSBI_PA_CMD fields */

#define SSBI_PA_CMD_RDWRN		(1 << 24)

#define SSBI_PA_CMD_ADDR_MASK		0x7fff 
/* REG_ADDR_7_0, REG_ADDR_8_14*/

/* SSBI_PA_RD_STATUS fields */

#define SSBI_PA_RD_STATUS_TRANS_DONE	(1 << 27)

#define SSBI_PA_RD_STATUS_TRANS_DENIED	(1 << 26)


#define SSBI_TIMEOUT_US			100


enum ssbi_controller_type {
	
MSM_SBI_CTRL_SSBI = 0,
	
MSM_SBI_CTRL_SSBI2,
	
MSM_SBI_CTRL_PMIC_ARBITER,
};


struct ssbi {
	
struct device		*slave;
	
void __iomem		*base;
	
spinlock_t		lock;
	
enum ssbi_controller_type controller_type;
	
int (*read)(struct ssbi *, u16 addr, u8 *buf, int len);
	
int (*write)(struct ssbi *, u16 addr, const u8 *buf, int len);
};


#define to_ssbi(dev)	platform_get_drvdata(to_platform_device(dev))



static inline u32 ssbi_readl(struct ssbi *ssbi, u32 reg)
{
	return readl(ssbi->base + reg);
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 24 96.00% 1 50.00%
David Brown 1 4.00% 1 50.00%
Total 25 100.00% 2 100.00%



static inline void ssbi_writel(struct ssbi *ssbi, u32 val, u32 reg)
{
	writel(val, ssbi->base + reg);
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 28 96.55% 1 50.00%
David Brown 1 3.45% 1 50.00%
Total 29 100.00% 2 100.00%

/*
 * Via private exchange with one of the original authors, the hardware
 * should generally finish a transaction in about 5us.  The worst
 * case, is when using the arbiter and both other CPUs have just
 * started trying to use the SSBI bus will result in a time of about
 * 20us.  It should never take longer than this.
 *
 * As such, this wait merely spins, with a udelay.
 */


static int ssbi_wait_mask(struct ssbi *ssbi, u32 set_mask, u32 clr_mask)
{
	u32 timeout = SSBI_TIMEOUT_US;
	u32 val;

	while (timeout--) {
		val = ssbi_readl(ssbi, SSBI2_STATUS);
		if (((val & set_mask) == set_mask) && ((val & clr_mask) == 0))
			return 0;
		udelay(1);
	}

	return -ETIMEDOUT;
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 74 98.67% 1 50.00%
David Brown 1 1.33% 1 50.00%
Total 75 100.00% 2 100.00%


static int

ssbi_read_bytes(struct ssbi *ssbi, u16 addr, u8 *buf, int len)
{
	u32 cmd = SSBI_CMD_RDWRN | ((addr & 0xff) << 16);
	int ret = 0;

	if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) {
		u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2);
		mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr);
		ssbi_writel(ssbi, mode2, SSBI2_MODE2);
	}

	while (len) {
		ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0);
		if (ret)
			goto err;

		ssbi_writel(ssbi, cmd, SSBI2_CMD);
		ret = ssbi_wait_mask(ssbi, SSBI_STATUS_RD_READY, 0);
		if (ret)
			goto err;
		*buf++ = ssbi_readl(ssbi, SSBI2_RD) & 0xff;
		len--;
	}

err:
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 149 98.68% 1 50.00%
David Brown 2 1.32% 1 50.00%
Total 151 100.00% 2 100.00%


static int

ssbi_write_bytes(struct ssbi *ssbi, u16 addr, const u8 *buf, int len)
{
	int ret = 0;

	if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) {
		u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2);
		mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr);
		ssbi_writel(ssbi, mode2, SSBI2_MODE2);
	}

	while (len) {
		ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0);
		if (ret)
			goto err;

		ssbi_writel(ssbi, ((addr & 0xff) << 16) | *buf, SSBI2_CMD);
		ret = ssbi_wait_mask(ssbi, 0, SSBI_STATUS_MCHN_BUSY);
		if (ret)
			goto err;
		buf++;
		len--;
	}

err:
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 135 97.83% 1 33.33%
David Brown 2 1.45% 1 33.33%
Stephen Boyd 1 0.72% 1 33.33%
Total 138 100.00% 3 100.00%

/*
 * See ssbi_wait_mask for an explanation of the time and the
 * busywait.
 */

static inline int

ssbi_pa_transfer(struct ssbi *ssbi, u32 cmd, u8 *data)
{
	u32 timeout = SSBI_TIMEOUT_US;
	u32 rd_status = 0;

	ssbi_writel(ssbi, cmd, SSBI_PA_CMD);

	while (timeout--) {
		rd_status = ssbi_readl(ssbi, SSBI_PA_RD_STATUS);

		if (rd_status & SSBI_PA_RD_STATUS_TRANS_DENIED)
			return -EPERM;

		if (rd_status & SSBI_PA_RD_STATUS_TRANS_DONE) {
			if (data)
				*data = rd_status & 0xff;
			return 0;
		}
		udelay(1);
	}

	return -ETIMEDOUT;
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 93 97.89% 1 50.00%
David Brown 2 2.11% 1 50.00%
Total 95 100.00% 2 100.00%


static int

ssbi_pa_read_bytes(struct ssbi *ssbi, u16 addr, u8 *buf, int len)
{
	u32 cmd;
	int ret = 0;

	cmd = SSBI_PA_CMD_RDWRN | (addr & SSBI_PA_CMD_ADDR_MASK) << 8;

	while (len) {
		ret = ssbi_pa_transfer(ssbi, cmd, buf);
		if (ret)
			goto err;
		buf++;
		len--;
	}

err:
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 73 96.05% 1 50.00%
David Brown 3 3.95% 1 50.00%
Total 76 100.00% 2 100.00%


static int

ssbi_pa_write_bytes(struct ssbi *ssbi, u16 addr, const u8 *buf, int len)
{
	u32 cmd;
	int ret = 0;

	while (len) {
		cmd = (addr & SSBI_PA_CMD_ADDR_MASK) << 8 | *buf;
		ret = ssbi_pa_transfer(ssbi, cmd, NULL);
		if (ret)
			goto err;
		buf++;
		len--;
	}

err:
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 74 94.87% 1 33.33%
David Brown 3 3.85% 1 33.33%
Stephen Boyd 1 1.28% 1 33.33%
Total 78 100.00% 3 100.00%



int ssbi_read(struct device *dev, u16 addr, u8 *buf, int len)
{
	struct ssbi *ssbi = to_ssbi(dev);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&ssbi->lock, flags);
	ret = ssbi->read(ssbi, addr, buf, len);
	spin_unlock_irqrestore(&ssbi->lock, flags);

	return ret;
}
Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 72 96.00% 1 50.00%
David Brown 3 4.00% 1 50.00%
Total 75 100.00% 2 100.00%


EXPORT_SYMBOL_GPL(ssbi_read);



int ssbi_write(struct device *dev, u16 addr, const u8 *buf, int len)
{
	struct ssbi *ssbi = to_ssbi(dev);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&ssbi->lock, flags);
	ret = ssbi->write(ssbi, addr, buf, len);
	spin_unlock_irqrestore(&ssbi->lock, flags);

	return ret;
}
Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 72 94.74% 1 33.33%
David Brown 3 3.95% 1 33.33%
Stephen Boyd 1 1.32% 1 33.33%
Total 76 100.00% 3 100.00%


EXPORT_SYMBOL_GPL(ssbi_write);



static int ssbi_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct resource *mem_res;
	struct ssbi *ssbi;
	const char *type;

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

	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ssbi->base = devm_ioremap_resource(&pdev->dev, mem_res);
	if (IS_ERR(ssbi->base))
		return PTR_ERR(ssbi->base);

	platform_set_drvdata(pdev, ssbi);

	type = of_get_property(np, "qcom,controller-type", NULL);
	if (type == NULL) {
		dev_err(&pdev->dev, "Missing qcom,controller-type property\n");
		return -EINVAL;
	}
	dev_info(&pdev->dev, "SSBI controller type: '%s'\n", type);
	if (strcmp(type, "ssbi") == 0)
		ssbi->controller_type = MSM_SBI_CTRL_SSBI;
	else if (strcmp(type, "ssbi2") == 0)
		ssbi->controller_type = MSM_SBI_CTRL_SSBI2;
	else if (strcmp(type, "pmic-arbiter") == 0)
		ssbi->controller_type = MSM_SBI_CTRL_PMIC_ARBITER;
	else {
		dev_err(&pdev->dev, "Unknown qcom,controller-type\n");
		return -EINVAL;
	}

	if (ssbi->controller_type == MSM_SBI_CTRL_PMIC_ARBITER) {
		ssbi->read = ssbi_pa_read_bytes;
		ssbi->write = ssbi_pa_write_bytes;
	} else {
		ssbi->read = ssbi_read_bytes;
		ssbi->write = ssbi_write_bytes;
	}

	spin_lock_init(&ssbi->lock);

	return of_platform_populate(np, NULL, NULL, &pdev->dev);
}

Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 137 47.57% 1 25.00%
David Brown 115 39.93% 2 50.00%
Stephen Boyd 36 12.50% 1 25.00%
Total 288 100.00% 4 100.00%


static const struct of_device_id ssbi_match_table[] = {
	{ .compatible = "qcom,ssbi" },
	{}
};
MODULE_DEVICE_TABLE(of, ssbi_match_table);


static struct platform_driver ssbi_driver = {
	.probe		= ssbi_probe,
	.driver		= {
		.name	= "ssbi",
		.of_match_table = ssbi_match_table,
        },
};

module_platform_driver(ssbi_driver);

MODULE_LICENSE("GPL v2");
MODULE_VERSION("1.0");
MODULE_ALIAS("platform:ssbi");
MODULE_AUTHOR("Dima Zavin <dima@android.com>");
Overall Contributors
Person Tokens Prop Commits CommitProp
Kenneth Heitke 1162 82.82% 1 10.00%
David Brown 180 12.83% 4 40.00%
Stephen Boyd 61 4.35% 5 50.00%
Total 1403 100.00% 10 100.00%
Directory: drivers/mfd

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.
Person	Tokens	Prop	Commits	CommitProp
Kenneth Heitke	24	96.00%	1	50.00%
David Brown	1	4.00%	1	50.00%
Total	25	100.00%	2	100.00%
cregit-Linux how code gets into the kernel

Release 4.14 drivers/mfd/ssbi.c

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Overall Contributors
