287 lines
7.1 KiB
C
287 lines
7.1 KiB
C
/*
|
|
* (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 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 resource *res_mem;
|
|
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;
|
|
|
|
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
i2c->twsi_base = devm_ioremap_resource(&pdev->dev, res_mem);
|
|
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 int octeon_i2c_remove(struct platform_device *pdev)
|
|
{
|
|
struct octeon_i2c *i2c = platform_get_drvdata(pdev);
|
|
|
|
i2c_del_adapter(&i2c->adap);
|
|
return 0;
|
|
};
|
|
|
|
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 = 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");
|