linux-stable/drivers/mfd/ssbi.c
Thomas Gleixner 97fb5e8d9b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 294 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.825281744@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00

328 lines
7.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/* 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.
*/
#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);
};
static inline u32 ssbi_readl(struct ssbi *ssbi, u32 reg)
{
return readl(ssbi->base + reg);
}
static inline void ssbi_writel(struct ssbi *ssbi, u32 val, u32 reg)
{
writel(val, ssbi->base + reg);
}
/*
* 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;
}
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;
}
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;
}
/*
* 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;
}
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;
}
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;
}
int ssbi_read(struct device *dev, u16 addr, u8 *buf, int len)
{
struct ssbi *ssbi = dev_get_drvdata(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;
}
EXPORT_SYMBOL_GPL(ssbi_read);
int ssbi_write(struct device *dev, u16 addr, const u8 *buf, int len)
{
struct ssbi *ssbi = dev_get_drvdata(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;
}
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 devm_of_platform_populate(&pdev->dev);
}
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>");