// SPDX-License-Identifier: GPL-2.0 /* * I2C multiplexer * * Copyright (c) 2008-2009 Rodolfo Giometti <[email protected]> * Copyright (c) 2008-2009 Eurotech S.p.A. <[email protected]> * * This module supports the PCA954x and PCA984x series of I2C multiplexer/switch * chips made by NXP Semiconductors. * This includes the: * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547, * PCA9548, PCA9846, PCA9847, PCA9848 and PCA9849. * * It's also compatible to Maxims MAX735x I2C switch chips, which are controlled * as the NXP PCA9548 and the MAX736x chips that act like the PCA9544. * * This includes the: * MAX7356, MAX7357, MAX7358, MAX7367, MAX7368 and MAX7369 * * These chips are all controlled via the I2C bus itself, and all have a * single 8-bit register. The upstream "parent" bus fans out to two, * four, or eight downstream busses or channels; which of these * are selected is determined by the chip type and register contents. A * mux can select only one sub-bus at a time; a switch can select any * combination simultaneously. * * Based on: * pca954x.c from Kumar Gala <[email protected]> * Copyright (C) 2006 * * Based on: * pca954x.c from Ken Harrenstien * Copyright (C) 2004 Google, Inc. (Ken Harrenstien) * * Based on: * i2c-virtual_cb.c from Brian Kuschak <[email protected]> * and * pca9540.c from Jean Delvare <[email protected]>. */ #include <linux/device.h> #include <linux/delay.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/i2c-mux.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/module.h> #include <linux/pm.h> #include <linux/property.h> #include <linux/regulator/consumer.h> #include <linux/reset.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <dt-bindings/mux/mux.h> #define PCA954X_MAX_NCHANS … #define PCA954X_IRQ_OFFSET … /* * MAX7357's configuration register is writeable after POR, but * can be locked by setting the basic mode bit. MAX7358 configuration * register is locked by default and needs to be unlocked first. * The configuration register holds the following settings: */ #define MAX7357_CONF_INT_ENABLE … #define MAX7357_CONF_FLUSH_OUT … #define MAX7357_CONF_RELEASE_INT … #define MAX7357_CONF_DISCON_SINGLE_CHAN … #define MAX7357_CONF_PRECONNECT_TEST … #define MAX7357_POR_DEFAULT_CONF … enum pca_type { … }; struct chip_desc { … }; struct pca954x { … }; /* Provide specs for the MAX735x, PCA954x and PCA984x types we know about */ static const struct chip_desc chips[] = …; static const struct i2c_device_id pca954x_id[] = …; MODULE_DEVICE_TABLE(i2c, pca954x_id); static const struct of_device_id pca954x_of_match[] = …; MODULE_DEVICE_TABLE(of, pca954x_of_match); /* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer() for this as they will try to lock adapter a second time */ static int pca954x_reg_write(struct i2c_adapter *adap, struct i2c_client *client, u8 val) { … } static u8 pca954x_regval(struct pca954x *data, u8 chan) { … } static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan) { … } static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan) { … } static ssize_t idle_state_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static ssize_t idle_state_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { … } static DEVICE_ATTR_RW(idle_state); static irqreturn_t pca954x_irq_handler(int irq, void *dev_id) { … } static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type) { … } static struct irq_chip pca954x_irq_chip = …; static int pca954x_irq_setup(struct i2c_mux_core *muxc) { … } static void pca954x_cleanup(struct i2c_mux_core *muxc) { … } static int pca954x_init(struct i2c_client *client, struct pca954x *data) { … } static int pca954x_get_reset(struct device *dev, struct pca954x *data) { … } static void pca954x_reset_deassert(struct pca954x *data) { … } /* * I2C init/probing/exit functions */ static int pca954x_probe(struct i2c_client *client) { … } static void pca954x_remove(struct i2c_client *client) { … } static int pca954x_resume(struct device *dev) { … } static DEFINE_SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume); static struct i2c_driver pca954x_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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