129 lines
3.1 KiB
C
129 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2021 The Asahi Linux Contributors
|
|
*
|
|
* PA Semi PWRficient SMBus host driver for Apple SoCs
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/types.h>
|
|
|
|
#include "i2c-pasemi-core.h"
|
|
|
|
struct pasemi_platform_i2c_data {
|
|
struct pasemi_smbus smbus;
|
|
struct clk *clk_ref;
|
|
};
|
|
|
|
static int
|
|
pasemi_platform_i2c_calc_clk_div(struct pasemi_platform_i2c_data *data,
|
|
u32 frequency)
|
|
{
|
|
unsigned long clk_rate = clk_get_rate(data->clk_ref);
|
|
|
|
if (!clk_rate)
|
|
return -EINVAL;
|
|
|
|
data->smbus.clk_div = DIV_ROUND_UP(clk_rate, 16 * frequency);
|
|
if (data->smbus.clk_div < 4)
|
|
return dev_err_probe(data->smbus.dev, -EINVAL,
|
|
"Bus frequency %d is too fast.\n",
|
|
frequency);
|
|
if (data->smbus.clk_div > 0xff)
|
|
return dev_err_probe(data->smbus.dev, -EINVAL,
|
|
"Bus frequency %d is too slow.\n",
|
|
frequency);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pasemi_platform_i2c_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct pasemi_platform_i2c_data *data;
|
|
struct pasemi_smbus *smbus;
|
|
u32 frequency;
|
|
int error;
|
|
int irq_num;
|
|
|
|
data = devm_kzalloc(dev, sizeof(struct pasemi_platform_i2c_data),
|
|
GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
smbus = &data->smbus;
|
|
smbus->dev = dev;
|
|
|
|
smbus->ioaddr = devm_platform_ioremap_resource(pdev, 0);
|
|
if (IS_ERR(smbus->ioaddr))
|
|
return PTR_ERR(smbus->ioaddr);
|
|
|
|
if (of_property_read_u32(dev->of_node, "clock-frequency", &frequency))
|
|
frequency = I2C_MAX_STANDARD_MODE_FREQ;
|
|
|
|
data->clk_ref = devm_clk_get(dev, NULL);
|
|
if (IS_ERR(data->clk_ref))
|
|
return PTR_ERR(data->clk_ref);
|
|
|
|
error = clk_prepare_enable(data->clk_ref);
|
|
if (error)
|
|
return error;
|
|
|
|
error = pasemi_platform_i2c_calc_clk_div(data, frequency);
|
|
if (error)
|
|
goto out_clk_disable;
|
|
|
|
smbus->adapter.dev.of_node = pdev->dev.of_node;
|
|
error = pasemi_i2c_common_probe(smbus);
|
|
if (error)
|
|
goto out_clk_disable;
|
|
|
|
irq_num = platform_get_irq(pdev, 0);
|
|
error = devm_request_irq(smbus->dev, irq_num, pasemi_irq_handler, 0, "pasemi_apple_i2c", (void *)smbus);
|
|
|
|
if (!error)
|
|
smbus->use_irq = 1;
|
|
platform_set_drvdata(pdev, data);
|
|
|
|
return 0;
|
|
|
|
out_clk_disable:
|
|
clk_disable_unprepare(data->clk_ref);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int pasemi_platform_i2c_remove(struct platform_device *pdev)
|
|
{
|
|
struct pasemi_platform_i2c_data *data = platform_get_drvdata(pdev);
|
|
|
|
clk_disable_unprepare(data->clk_ref);
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id pasemi_platform_i2c_of_match[] = {
|
|
{ .compatible = "apple,t8103-i2c" },
|
|
{ .compatible = "apple,i2c" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, pasemi_platform_i2c_of_match);
|
|
|
|
static struct platform_driver pasemi_platform_i2c_driver = {
|
|
.driver = {
|
|
.name = "i2c-apple",
|
|
.of_match_table = pasemi_platform_i2c_of_match,
|
|
},
|
|
.probe = pasemi_platform_i2c_probe,
|
|
.remove = pasemi_platform_i2c_remove,
|
|
};
|
|
module_platform_driver(pasemi_platform_i2c_driver);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
|
|
MODULE_DESCRIPTION("Apple/PASemi SMBus platform driver");
|