From d88ae2932df0e670610cb741fec442ad12466c03 Mon Sep 17 00:00:00 2001 From: Sven Peter Date: Fri, 8 Oct 2021 18:35:31 +0200 Subject: [PATCH] i2c: pasemi: Add Apple platform driver With all the previous preparations we can now finally add the platform driver to support the PASemi-based controllers in Apple SoCs. This does not work on the M1 yet but should work on the early iPhones already. Reviewed-by: Arnd Bergmann Signed-off-by: Sven Peter Acked-by: Olof Johansson Tested-by: Christian Zigotzky Signed-off-by: Wolfram Sang --- drivers/i2c/busses/Kconfig | 11 ++ drivers/i2c/busses/Makefile | 2 + drivers/i2c/busses/i2c-pasemi-platform.c | 122 +++++++++++++++++++++++ 3 files changed, 135 insertions(+) create mode 100644 drivers/i2c/busses/i2c-pasemi-platform.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 1df19ccc310b..dce392839017 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -859,6 +859,17 @@ config I2C_PASEMI help Supports the PA Semi PWRficient on-chip SMBus interfaces. +config I2C_APPLE + tristate "Apple SMBus platform driver" + depends on ARCH_APPLE || COMPILE_TEST + default ARCH_APPLE + help + Say Y here if you want to use the I2C controller present on Apple + Silicon chips such as the M1. + + This driver can also be built as a module. If so, the module + will be called i2c-apple. + config I2C_PCA_PLATFORM tristate "PCA9564/PCA9665 as platform device" select I2C_ALGOPCA diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 0ab1b4cb2228..d85899fef8c7 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -86,6 +86,8 @@ obj-$(CONFIG_I2C_OMAP) += i2c-omap.o obj-$(CONFIG_I2C_OWL) += i2c-owl.o i2c-pasemi-objs := i2c-pasemi-core.o i2c-pasemi-pci.o obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o +i2c-apple-objs := i2c-pasemi-core.o i2c-pasemi-platform.o +obj-$(CONFIG_I2C_APPLE) += i2c-apple.o obj-$(CONFIG_I2C_PCA_PLATFORM) += i2c-pca-platform.o obj-$(CONFIG_I2C_PNX) += i2c-pnx.o obj-$(CONFIG_I2C_PXA) += i2c-pxa.o diff --git a/drivers/i2c/busses/i2c-pasemi-platform.c b/drivers/i2c/busses/i2c-pasemi-platform.c new file mode 100644 index 000000000000..88a54aaf7e3c --- /dev/null +++ b/drivers/i2c/busses/i2c-pasemi-platform.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 The Asahi Linux Contributors + * + * PA Semi PWRficient SMBus host driver for Apple SoCs + */ + +#include +#include +#include +#include +#include +#include +#include + +#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 "); +MODULE_DESCRIPTION("Apple/PASemi SMBus platform driver");