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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2021 The Asahi Linux Contributors4 *5 * PA Semi PWRficient SMBus host driver for Apple SoCs6 */7 8#include <linux/clk.h>9#include <linux/i2c.h>10#include <linux/io.h>11#include <linux/kernel.h>12#include <linux/module.h>13#include <linux/platform_device.h>14#include <linux/types.h>15 16#include "i2c-pasemi-core.h"17 18struct pasemi_platform_i2c_data {19 struct pasemi_smbus smbus;20 struct clk *clk_ref;21};22 23static int24pasemi_platform_i2c_calc_clk_div(struct pasemi_platform_i2c_data *data,25 u32 frequency)26{27 unsigned long clk_rate = clk_get_rate(data->clk_ref);28 29 if (!clk_rate)30 return -EINVAL;31 32 data->smbus.clk_div = DIV_ROUND_UP(clk_rate, 16 * frequency);33 if (data->smbus.clk_div < 4)34 return dev_err_probe(data->smbus.dev, -EINVAL,35 "Bus frequency %d is too fast.\n",36 frequency);37 if (data->smbus.clk_div > 0xff)38 return dev_err_probe(data->smbus.dev, -EINVAL,39 "Bus frequency %d is too slow.\n",40 frequency);41 42 return 0;43}44 45static int pasemi_platform_i2c_probe(struct platform_device *pdev)46{47 struct device *dev = &pdev->dev;48 struct pasemi_platform_i2c_data *data;49 struct pasemi_smbus *smbus;50 u32 frequency;51 int error;52 int irq_num;53 54 data = devm_kzalloc(dev, sizeof(struct pasemi_platform_i2c_data),55 GFP_KERNEL);56 if (!data)57 return -ENOMEM;58 59 smbus = &data->smbus;60 smbus->dev = dev;61 62 smbus->ioaddr = devm_platform_ioremap_resource(pdev, 0);63 if (IS_ERR(smbus->ioaddr))64 return PTR_ERR(smbus->ioaddr);65 66 if (of_property_read_u32(dev->of_node, "clock-frequency", &frequency))67 frequency = I2C_MAX_STANDARD_MODE_FREQ;68 69 data->clk_ref = devm_clk_get_enabled(dev, NULL);70 if (IS_ERR(data->clk_ref))71 return PTR_ERR(data->clk_ref);72 73 error = pasemi_platform_i2c_calc_clk_div(data, frequency);74 if (error)75 return error;76 77 smbus->adapter.dev.of_node = pdev->dev.of_node;78 error = pasemi_i2c_common_probe(smbus);79 if (error)80 return error;81 82 irq_num = platform_get_irq(pdev, 0);83 error = devm_request_irq(smbus->dev, irq_num, pasemi_irq_handler, 0, "pasemi_apple_i2c", (void *)smbus);84 85 if (!error)86 smbus->use_irq = 1;87 platform_set_drvdata(pdev, data);88 89 return 0;90}91 92static void pasemi_platform_i2c_remove(struct platform_device *pdev) { }93 94static const struct of_device_id pasemi_platform_i2c_of_match[] = {95 { .compatible = "apple,t8103-i2c" },96 { .compatible = "apple,i2c" },97 {},98};99MODULE_DEVICE_TABLE(of, pasemi_platform_i2c_of_match);100 101static struct platform_driver pasemi_platform_i2c_driver = {102 .driver = {103 .name = "i2c-apple",104 .of_match_table = pasemi_platform_i2c_of_match,105 },106 .probe = pasemi_platform_i2c_probe,107 .remove_new = pasemi_platform_i2c_remove,108};109module_platform_driver(pasemi_platform_i2c_driver);110 111MODULE_LICENSE("GPL");112MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");113MODULE_DESCRIPTION("Apple/PASemi SMBus platform driver");114