/*
* (C) Copyright 2009-2010
* Nokia Siemens Networks, michael.lawnick.ext@nsn.com
*
* Portions Copyright (C) 2010 - 2016 Cavium, Inc.
*
* This is a driver for the i2c adapter in Cavium Networks' OCTEON processors.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/atomic.h>
#include <linux/delay.h>
#include <linux/i2c.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/sched.h>
#include <linux/slab.h>
#include <asm/octeon/octeon.h>
#include "i2c-octeon-core.h"
#define DRV_NAME "i2c-octeon"
/**
* octeon_i2c_int_enable - enable the CORE interrupt
* @i2c: The struct octeon_i2c
*
* The interrupt will be asserted when there is non-STAT_IDLE state in
* the SW_TWSI_EOP_TWSI_STAT register.
*/
static void octeon_i2c_int_enable(struct octeon_i2c *i2c)
{
octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN);
}
/* disable the CORE interrupt */
static void octeon_i2c_int_disable(struct octeon_i2c *i2c)
{
/* clear TS/ST/IFLG events */
octeon_i2c_write_int(i2c, 0);
}
/**
* octeon_i2c_int_enable78 - enable the CORE interrupt
* @i2c: The struct octeon_i2c
*
* The interrupt will be asserted when there is non-STAT_IDLE state in the
* SW_TWSI_EOP_TWSI_STAT register.
*/
static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)
{
atomic_inc_return(&i2c->int_enable_cnt);
enable_irq(i2c->irq);
}
static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)
{
int count;
/*
* The interrupt can be disabled in two places, but we only
* want to make the disable_irq_nosync() call once, so keep
* track with the atomic variable.
*/
count = atomic_dec_if_positive(cnt);
if (count >= 0)
disable_irq_nosync(irq);
}
/* disable the CORE interrupt */
static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)
{
__octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq);
}
/**
* octeon_i2c_hlc_int_enable78 - enable the ST interrupt
* @i2c: The struct octeon_i2c
*
* The interrupt will be asserted when there is non-STAT_IDLE state in
* the SW_TWSI_EOP_TWSI_STAT register.
*/
static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)
{
atomic_inc_return(&i2c->hlc_int_enable_cnt);
enable_irq(i2c->hlc_irq);
}
/* disable the ST interrupt */
static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)
{
__octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);
}
/* HLC interrupt service routine */
static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
{
struct octeon_i2c *i2c = dev_id;
i2c->hlc_int_disable(i2c);
wake_up(&i2c->queue);
return IRQ_HANDLED;
}
static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
{
octeon_i2c_write_int(i2c, TWSI_INT_ST_EN);
}
static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
}
static const struct i2c_algorithm octeon_i2c_algo = {
.master_xfer = octeon_i2c_xfer,
.functionality = octeon_i2c_functionality,
};
static const struct i2c_adapter octeon_i2c_ops = {
.owner = THIS_MODULE,
.name = "OCTEON adapter",
.algo = &octeon_i2c_algo,
};
static int octeon_i2c_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
int irq, result = 0, hlc_irq = 0;
struct octeon_i2c *i2c;
bool cn78xx_style;
cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");
if (cn78xx_style) {
hlc_irq = platform_get_irq(pdev, 0);
if (hlc_irq < 0)
return hlc_irq;
irq = platform_get_irq(pdev, 2);
if (irq < 0)
return irq;
} else {
/* All adaptors have an irq. */
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
}
i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
if (!i2c) {
result = -ENOMEM;
goto out;
}
i2c->dev = &pdev->dev;
i2c->roff.sw_twsi = 0x00;
i2c->roff.twsi_int = 0x10;
i2c->roff.sw_twsi_ext = 0x18;
i2c->twsi_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(i2c->twsi_base)) {
result = PTR_ERR(i2c->twsi_base);
goto out;
}
/*
* "clock-rate" is a legacy binding, the official binding is
* "clock-frequency". Try the official one first and then
* fall back if it doesn't exist.
*/
if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) &&
of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) {
dev_err(i2c->dev,
"no I2C 'clock-rate' or 'clock-frequency' property\n");
result = -ENXIO;
goto out;
}
i2c->sys_freq = octeon_get_io_clock_rate();
init_waitqueue_head(&i2c->queue);
i2c->irq = irq;
if (cn78xx_style) {
i2c->hlc_irq = hlc_irq;
i2c->int_enable = octeon_i2c_int_enable78;
i2c->int_disable = octeon_i2c_int_disable78;
i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78;
i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78;
irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);
irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);
result = devm_request_irq(&pdev->dev, i2c->hlc_irq,
octeon_i2c_hlc_isr78, 0,
DRV_NAME, i2c);
if (result < 0) {
dev_err(i2c->dev, "failed to attach interrupt\n");
goto out;
}
} else {
i2c->int_enable = octeon_i2c_int_enable;
i2c->int_disable = octeon_i2c_int_disable;
i2c->hlc_int_enable = octeon_i2c_hlc_int_enable;
i2c->hlc_int_disable = octeon_i2c_int_disable;
}
result = devm_request_irq(&pdev->dev, i2c->irq,
octeon_i2c_isr, 0, DRV_NAME, i2c);
if (result < 0) {
dev_err(i2c->dev, "failed to attach interrupt\n");
goto out;
}
if (OCTEON_IS_MODEL(OCTEON_CN38XX))
i2c->broken_irq_check = true;
result = octeon_i2c_init_lowlevel(i2c);
if (result) {
dev_err(i2c->dev, "init low level failed\n");
goto out;
}
octeon_i2c_set_clock(i2c);
i2c->adap = octeon_i2c_ops;
i2c->adap.timeout = msecs_to_jiffies(2);
i2c->adap.retries = 5;
i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
i2c->adap.dev.parent = &pdev->dev;
i2c->adap.dev.of_node = node;
i2c_set_adapdata(&i2c->adap, i2c);
platform_set_drvdata(pdev, i2c);
result = i2c_add_adapter(&i2c->adap);
if (result < 0)
goto out;
dev_info(i2c->dev, "probed\n");
return 0;
out:
return result;
};
static void octeon_i2c_remove(struct platform_device *pdev)
{
struct octeon_i2c *i2c = platform_get_drvdata(pdev);
i2c_del_adapter(&i2c->adap);
};
static const struct of_device_id octeon_i2c_match[] = {
{ .compatible = "cavium,octeon-3860-twsi", },
{ .compatible = "cavium,octeon-7890-twsi", },
{},
};
MODULE_DEVICE_TABLE(of, octeon_i2c_match);
static struct platform_driver octeon_i2c_driver = {
.probe = octeon_i2c_probe,
.remove_new = octeon_i2c_remove,
.driver = {
.name = DRV_NAME,
.of_match_table = octeon_i2c_match,
},
};
module_platform_driver(octeon_i2c_driver);
MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>");
MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors");
MODULE_LICENSE("GPL");