linux-imx

/*

 * I2C multiplexer

 *

 * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>

 * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>

 *

 * This module supports the PCA954x and PCA954x 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.

 *

 * 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 <galak@kernel.crashing.org>

 * 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 <bkuschak@yahoo.com>

 * and

 *  pca9540.c from Jean Delvare <jdelvare@suse.de>.

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */

​

#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/of.h>

#include <linux/of_device.h>

#include <linux/of_irq.h>

#include <linux/pm.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <dt-bindings/mux/mux.h>

​

#define PCA954X_MAX_NCHANS 8

​

#define PCA954X_IRQ_OFFSET 4

​

enum pca_type {

    pca_9540,

    pca_9542,

    pca_9543,

    pca_9544,

    pca_9545,

    pca_9546,

    pca_9547,

    pca_9548,

    pca_9846,

    pca_9847,

    pca_9848,

    pca_9849,

};

​

struct chip_desc {

    u8 nchans;

    u8 enable;  /* used for muxes only */

    u8 has_irq;

    enum muxtype {

        pca954x_ismux = 0,

        pca954x_isswi

    } muxtype;

    struct i2c_device_identity id;

};

​

struct pca954x {

    const struct chip_desc *chip;

​

    u8 last_chan;       /* last register value */

    /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */

    s8 idle_state;

​

    struct i2c_client *client;

​