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- #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;
- 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;
- 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");
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