mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
a5eacd2e37
.probe_new() doesn't get the i2c_device_id * parameter, so determine that explicitly in the probe function. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@kernel.org>
566 lines
14 KiB
C
566 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* 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 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.
|
|
*
|
|
* 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>.
|
|
*/
|
|
|
|
#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/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 */
|
|
s32 idle_state;
|
|
|
|
struct i2c_client *client;
|
|
|
|
struct irq_domain *irq;
|
|
unsigned int irq_mask;
|
|
raw_spinlock_t lock;
|
|
};
|
|
|
|
/* Provide specs for the PCA954x types we know about */
|
|
static const struct chip_desc chips[] = {
|
|
[pca_9540] = {
|
|
.nchans = 2,
|
|
.enable = 0x4,
|
|
.muxtype = pca954x_ismux,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9542] = {
|
|
.nchans = 2,
|
|
.enable = 0x4,
|
|
.has_irq = 1,
|
|
.muxtype = pca954x_ismux,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9543] = {
|
|
.nchans = 2,
|
|
.has_irq = 1,
|
|
.muxtype = pca954x_isswi,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9544] = {
|
|
.nchans = 4,
|
|
.enable = 0x4,
|
|
.has_irq = 1,
|
|
.muxtype = pca954x_ismux,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9545] = {
|
|
.nchans = 4,
|
|
.has_irq = 1,
|
|
.muxtype = pca954x_isswi,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9546] = {
|
|
.nchans = 4,
|
|
.muxtype = pca954x_isswi,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9547] = {
|
|
.nchans = 8,
|
|
.enable = 0x8,
|
|
.muxtype = pca954x_ismux,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9548] = {
|
|
.nchans = 8,
|
|
.muxtype = pca954x_isswi,
|
|
.id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
|
|
},
|
|
[pca_9846] = {
|
|
.nchans = 4,
|
|
.muxtype = pca954x_isswi,
|
|
.id = {
|
|
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
|
|
.part_id = 0x10b,
|
|
},
|
|
},
|
|
[pca_9847] = {
|
|
.nchans = 8,
|
|
.enable = 0x8,
|
|
.muxtype = pca954x_ismux,
|
|
.id = {
|
|
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
|
|
.part_id = 0x108,
|
|
},
|
|
},
|
|
[pca_9848] = {
|
|
.nchans = 8,
|
|
.muxtype = pca954x_isswi,
|
|
.id = {
|
|
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
|
|
.part_id = 0x10a,
|
|
},
|
|
},
|
|
[pca_9849] = {
|
|
.nchans = 4,
|
|
.enable = 0x4,
|
|
.muxtype = pca954x_ismux,
|
|
.id = {
|
|
.manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
|
|
.part_id = 0x109,
|
|
},
|
|
},
|
|
};
|
|
|
|
static const struct i2c_device_id pca954x_id[] = {
|
|
{ "pca9540", pca_9540 },
|
|
{ "pca9542", pca_9542 },
|
|
{ "pca9543", pca_9543 },
|
|
{ "pca9544", pca_9544 },
|
|
{ "pca9545", pca_9545 },
|
|
{ "pca9546", pca_9546 },
|
|
{ "pca9547", pca_9547 },
|
|
{ "pca9548", pca_9548 },
|
|
{ "pca9846", pca_9846 },
|
|
{ "pca9847", pca_9847 },
|
|
{ "pca9848", pca_9848 },
|
|
{ "pca9849", pca_9849 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, pca954x_id);
|
|
|
|
static const struct of_device_id pca954x_of_match[] = {
|
|
{ .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
|
|
{ .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
|
|
{ .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
|
|
{ .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
|
|
{ .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
|
|
{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
|
|
{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
|
|
{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
|
|
{ .compatible = "nxp,pca9846", .data = &chips[pca_9846] },
|
|
{ .compatible = "nxp,pca9847", .data = &chips[pca_9847] },
|
|
{ .compatible = "nxp,pca9848", .data = &chips[pca_9848] },
|
|
{ .compatible = "nxp,pca9849", .data = &chips[pca_9849] },
|
|
{}
|
|
};
|
|
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)
|
|
{
|
|
union i2c_smbus_data dummy;
|
|
|
|
return __i2c_smbus_xfer(adap, client->addr, client->flags,
|
|
I2C_SMBUS_WRITE, val,
|
|
I2C_SMBUS_BYTE, &dummy);
|
|
}
|
|
|
|
static u8 pca954x_regval(struct pca954x *data, u8 chan)
|
|
{
|
|
/* We make switches look like muxes, not sure how to be smarter. */
|
|
if (data->chip->muxtype == pca954x_ismux)
|
|
return chan | data->chip->enable;
|
|
else
|
|
return 1 << chan;
|
|
}
|
|
|
|
static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
|
|
{
|
|
struct pca954x *data = i2c_mux_priv(muxc);
|
|
struct i2c_client *client = data->client;
|
|
u8 regval;
|
|
int ret = 0;
|
|
|
|
regval = pca954x_regval(data, chan);
|
|
/* Only select the channel if its different from the last channel */
|
|
if (data->last_chan != regval) {
|
|
ret = pca954x_reg_write(muxc->parent, client, regval);
|
|
data->last_chan = ret < 0 ? 0 : regval;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
|
|
{
|
|
struct pca954x *data = i2c_mux_priv(muxc);
|
|
struct i2c_client *client = data->client;
|
|
s32 idle_state;
|
|
|
|
idle_state = READ_ONCE(data->idle_state);
|
|
if (idle_state >= 0)
|
|
/* Set the mux back to a predetermined channel */
|
|
return pca954x_select_chan(muxc, idle_state);
|
|
|
|
if (idle_state == MUX_IDLE_DISCONNECT) {
|
|
/* Deselect active channel */
|
|
data->last_chan = 0;
|
|
return pca954x_reg_write(muxc->parent, client,
|
|
data->last_chan);
|
|
}
|
|
|
|
/* otherwise leave as-is */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t idle_state_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
struct i2c_mux_core *muxc = i2c_get_clientdata(client);
|
|
struct pca954x *data = i2c_mux_priv(muxc);
|
|
|
|
return sprintf(buf, "%d\n", READ_ONCE(data->idle_state));
|
|
}
|
|
|
|
static ssize_t idle_state_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
struct i2c_mux_core *muxc = i2c_get_clientdata(client);
|
|
struct pca954x *data = i2c_mux_priv(muxc);
|
|
int val;
|
|
int ret;
|
|
|
|
ret = kstrtoint(buf, 0, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (val != MUX_IDLE_AS_IS && val != MUX_IDLE_DISCONNECT &&
|
|
(val < 0 || val >= data->chip->nchans))
|
|
return -EINVAL;
|
|
|
|
i2c_lock_bus(muxc->parent, I2C_LOCK_SEGMENT);
|
|
|
|
WRITE_ONCE(data->idle_state, val);
|
|
/*
|
|
* Set the mux into a state consistent with the new
|
|
* idle_state.
|
|
*/
|
|
if (data->last_chan || val != MUX_IDLE_DISCONNECT)
|
|
ret = pca954x_deselect_mux(muxc, 0);
|
|
|
|
i2c_unlock_bus(muxc->parent, I2C_LOCK_SEGMENT);
|
|
|
|
return ret < 0 ? ret : count;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(idle_state);
|
|
|
|
static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
|
|
{
|
|
struct pca954x *data = dev_id;
|
|
unsigned long pending;
|
|
int ret, i;
|
|
|
|
ret = i2c_smbus_read_byte(data->client);
|
|
if (ret < 0)
|
|
return IRQ_NONE;
|
|
|
|
pending = (ret >> PCA954X_IRQ_OFFSET) & (BIT(data->chip->nchans) - 1);
|
|
for_each_set_bit(i, &pending, data->chip->nchans)
|
|
handle_nested_irq(irq_linear_revmap(data->irq, i));
|
|
|
|
return IRQ_RETVAL(pending);
|
|
}
|
|
|
|
static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
|
|
{
|
|
if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static struct irq_chip pca954x_irq_chip = {
|
|
.name = "i2c-mux-pca954x",
|
|
.irq_set_type = pca954x_irq_set_type,
|
|
};
|
|
|
|
static int pca954x_irq_setup(struct i2c_mux_core *muxc)
|
|
{
|
|
struct pca954x *data = i2c_mux_priv(muxc);
|
|
struct i2c_client *client = data->client;
|
|
int c, irq;
|
|
|
|
if (!data->chip->has_irq || client->irq <= 0)
|
|
return 0;
|
|
|
|
raw_spin_lock_init(&data->lock);
|
|
|
|
data->irq = irq_domain_add_linear(client->dev.of_node,
|
|
data->chip->nchans,
|
|
&irq_domain_simple_ops, data);
|
|
if (!data->irq)
|
|
return -ENODEV;
|
|
|
|
for (c = 0; c < data->chip->nchans; c++) {
|
|
irq = irq_create_mapping(data->irq, c);
|
|
if (!irq) {
|
|
dev_err(&client->dev, "failed irq create map\n");
|
|
return -EINVAL;
|
|
}
|
|
irq_set_chip_data(irq, data);
|
|
irq_set_chip_and_handler(irq, &pca954x_irq_chip,
|
|
handle_simple_irq);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void pca954x_cleanup(struct i2c_mux_core *muxc)
|
|
{
|
|
struct pca954x *data = i2c_mux_priv(muxc);
|
|
int c, irq;
|
|
|
|
if (data->irq) {
|
|
for (c = 0; c < data->chip->nchans; c++) {
|
|
irq = irq_find_mapping(data->irq, c);
|
|
irq_dispose_mapping(irq);
|
|
}
|
|
irq_domain_remove(data->irq);
|
|
}
|
|
i2c_mux_del_adapters(muxc);
|
|
}
|
|
|
|
static int pca954x_init(struct i2c_client *client, struct pca954x *data)
|
|
{
|
|
int ret;
|
|
|
|
if (data->idle_state >= 0)
|
|
data->last_chan = pca954x_regval(data, data->idle_state);
|
|
else
|
|
data->last_chan = 0; /* Disconnect multiplexer */
|
|
|
|
ret = i2c_smbus_write_byte(client, data->last_chan);
|
|
if (ret < 0)
|
|
data->last_chan = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* I2C init/probing/exit functions
|
|
*/
|
|
static int pca954x_probe(struct i2c_client *client)
|
|
{
|
|
const struct i2c_device_id *id = i2c_client_get_device_id(client);
|
|
struct i2c_adapter *adap = client->adapter;
|
|
struct device *dev = &client->dev;
|
|
struct gpio_desc *gpio;
|
|
struct i2c_mux_core *muxc;
|
|
struct pca954x *data;
|
|
int num;
|
|
int ret;
|
|
|
|
if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
|
|
return -ENODEV;
|
|
|
|
muxc = i2c_mux_alloc(adap, dev, PCA954X_MAX_NCHANS, sizeof(*data), 0,
|
|
pca954x_select_chan, pca954x_deselect_mux);
|
|
if (!muxc)
|
|
return -ENOMEM;
|
|
data = i2c_mux_priv(muxc);
|
|
|
|
i2c_set_clientdata(client, muxc);
|
|
data->client = client;
|
|
|
|
/* Reset the mux if a reset GPIO is specified. */
|
|
gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
|
|
if (IS_ERR(gpio))
|
|
return PTR_ERR(gpio);
|
|
if (gpio) {
|
|
udelay(1);
|
|
gpiod_set_value_cansleep(gpio, 0);
|
|
/* Give the chip some time to recover. */
|
|
udelay(1);
|
|
}
|
|
|
|
data->chip = device_get_match_data(dev);
|
|
if (!data->chip)
|
|
data->chip = &chips[id->driver_data];
|
|
|
|
if (data->chip->id.manufacturer_id != I2C_DEVICE_ID_NONE) {
|
|
struct i2c_device_identity id;
|
|
|
|
ret = i2c_get_device_id(client, &id);
|
|
if (ret && ret != -EOPNOTSUPP)
|
|
return ret;
|
|
|
|
if (!ret &&
|
|
(id.manufacturer_id != data->chip->id.manufacturer_id ||
|
|
id.part_id != data->chip->id.part_id)) {
|
|
dev_warn(dev, "unexpected device id %03x-%03x-%x\n",
|
|
id.manufacturer_id, id.part_id,
|
|
id.die_revision);
|
|
return -ENODEV;
|
|
}
|
|
}
|
|
|
|
data->idle_state = MUX_IDLE_AS_IS;
|
|
if (device_property_read_u32(dev, "idle-state", &data->idle_state)) {
|
|
if (device_property_read_bool(dev, "i2c-mux-idle-disconnect"))
|
|
data->idle_state = MUX_IDLE_DISCONNECT;
|
|
}
|
|
|
|
/*
|
|
* Write the mux register at addr to verify
|
|
* that the mux is in fact present. This also
|
|
* initializes the mux to a channel
|
|
* or disconnected state.
|
|
*/
|
|
ret = pca954x_init(client, data);
|
|
if (ret < 0) {
|
|
dev_warn(dev, "probe failed\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
ret = pca954x_irq_setup(muxc);
|
|
if (ret)
|
|
goto fail_cleanup;
|
|
|
|
/* Now create an adapter for each channel */
|
|
for (num = 0; num < data->chip->nchans; num++) {
|
|
ret = i2c_mux_add_adapter(muxc, 0, num, 0);
|
|
if (ret)
|
|
goto fail_cleanup;
|
|
}
|
|
|
|
if (data->irq) {
|
|
ret = devm_request_threaded_irq(dev, data->client->irq,
|
|
NULL, pca954x_irq_handler,
|
|
IRQF_ONESHOT | IRQF_SHARED,
|
|
"pca954x", data);
|
|
if (ret)
|
|
goto fail_cleanup;
|
|
}
|
|
|
|
/*
|
|
* The attr probably isn't going to be needed in most cases,
|
|
* so don't fail completely on error.
|
|
*/
|
|
device_create_file(dev, &dev_attr_idle_state);
|
|
|
|
dev_info(dev, "registered %d multiplexed busses for I2C %s %s\n",
|
|
num, data->chip->muxtype == pca954x_ismux
|
|
? "mux" : "switch", client->name);
|
|
|
|
return 0;
|
|
|
|
fail_cleanup:
|
|
pca954x_cleanup(muxc);
|
|
return ret;
|
|
}
|
|
|
|
static void pca954x_remove(struct i2c_client *client)
|
|
{
|
|
struct i2c_mux_core *muxc = i2c_get_clientdata(client);
|
|
|
|
device_remove_file(&client->dev, &dev_attr_idle_state);
|
|
|
|
pca954x_cleanup(muxc);
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int pca954x_resume(struct device *dev)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
struct i2c_mux_core *muxc = i2c_get_clientdata(client);
|
|
struct pca954x *data = i2c_mux_priv(muxc);
|
|
int ret;
|
|
|
|
ret = pca954x_init(client, data);
|
|
if (ret < 0)
|
|
dev_err(&client->dev, "failed to verify mux presence\n");
|
|
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
|
|
|
|
static struct i2c_driver pca954x_driver = {
|
|
.driver = {
|
|
.name = "pca954x",
|
|
.pm = &pca954x_pm,
|
|
.of_match_table = pca954x_of_match,
|
|
},
|
|
.probe_new = pca954x_probe,
|
|
.remove = pca954x_remove,
|
|
.id_table = pca954x_id,
|
|
};
|
|
|
|
module_i2c_driver(pca954x_driver);
|
|
|
|
MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
|
|
MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
|
|
MODULE_LICENSE("GPL v2");
|