i2c: muxes: rename first set of drivers to a standard pattern

Apply a naming pattern like in the rest of the subsystem to a first set
of mux drivers. Those drivers are the low-hanging fruit; we want to pick
them to motivate upcoming drivers to follow the new pattern. The missing
GPIO driver will be converted in a later patch.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com> (pca9541)
Acked-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 0 insertions, 401 deletions

diff --git a/drivers/i2c/muxes/pca9541.c b/drivers/i2c/muxes/pca9541.c
deleted file mode 100644
index 8aacde1516ac..000000000000
--- a/drivers/i2c/muxes/pca9541.c
+++ /dev/null
@@ -1,401 +0,0 @@
-/*
- * I2C multiplexer driver for PCA9541 bus master selector
- *
- * Copyright (c) 2010 Ericsson AB.
- *
- * Author: Guenter Roeck <guenter.roeck@ericsson.com>
- *
- * Derived from:
- *  pca954x.c
- *
- *  Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
- *  Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
- *
- * 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/module.h>
-#include <linux/init.h>
-#include <linux/jiffies.h>
-#include <linux/delay.h>
-#include <linux/slab.h>
-#include <linux/device.h>
-#include <linux/i2c.h>
-#include <linux/i2c-mux.h>
-
-#include <linux/i2c/pca954x.h>
-
-/*
- * The PCA9541 is a bus master selector. It supports two I2C masters connected
- * to a single slave bus.
- *
- * Before each bus transaction, a master has to acquire bus ownership. After the
- * transaction is complete, bus ownership has to be released. This fits well
- * into the I2C multiplexer framework, which provides select and release
- * functions for this purpose. For this reason, this driver is modeled as
- * single-channel I2C bus multiplexer.
- *
- * This driver assumes that the two bus masters are controlled by two different
- * hosts. If a single host controls both masters, platform code has to ensure
- * that only one of the masters is instantiated at any given time.
- */
-
-#define PCA9541_CONTROL		0x01
-#define PCA9541_ISTAT		0x02
-
-#define PCA9541_CTL_MYBUS	(1 << 0)
-#define PCA9541_CTL_NMYBUS	(1 << 1)
-#define PCA9541_CTL_BUSON	(1 << 2)
-#define PCA9541_CTL_NBUSON	(1 << 3)
-#define PCA9541_CTL_BUSINIT	(1 << 4)
-#define PCA9541_CTL_TESTON	(1 << 6)
-#define PCA9541_CTL_NTESTON	(1 << 7)
-
-#define PCA9541_ISTAT_INTIN	(1 << 0)
-#define PCA9541_ISTAT_BUSINIT	(1 << 1)
-#define PCA9541_ISTAT_BUSOK	(1 << 2)
-#define PCA9541_ISTAT_BUSLOST	(1 << 3)
-#define PCA9541_ISTAT_MYTEST	(1 << 6)
-#define PCA9541_ISTAT_NMYTEST	(1 << 7)
-
-#define BUSON		(PCA9541_CTL_BUSON | PCA9541_CTL_NBUSON)
-#define MYBUS		(PCA9541_CTL_MYBUS | PCA9541_CTL_NMYBUS)
-#define mybus(x)	(!((x) & MYBUS) || ((x) & MYBUS) == MYBUS)
-#define busoff(x)	(!((x) & BUSON) || ((x) & BUSON) == BUSON)
-
-/* arbitration timeouts, in jiffies */
-#define ARB_TIMEOUT	(HZ / 8)	/* 125 ms until forcing bus ownership */
-#define ARB2_TIMEOUT	(HZ / 4)	/* 250 ms until acquisition failure */
-
-/* arbitration retry delays, in us */
-#define SELECT_DELAY_SHORT	50
-#define SELECT_DELAY_LONG	1000
-
-struct pca9541 {
-	struct i2c_adapter *mux_adap;
-	unsigned long select_timeout;
-	unsigned long arb_timeout;
-};
-
-static const struct i2c_device_id pca9541_id[] = {
-	{"pca9541", 0},
-	{}
-};
-
-MODULE_DEVICE_TABLE(i2c, pca9541_id);
-
-/*
- * Write to chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
- * as they will try to lock the adapter a second time.
- */
-static int pca9541_reg_write(struct i2c_client *client, u8 command, u8 val)
-{
-	struct i2c_adapter *adap = client->adapter;
-	int ret;
-
-	if (adap->algo->master_xfer) {
-		struct i2c_msg msg;
-		char buf[2];
-
-		msg.addr = client->addr;
-		msg.flags = 0;
-		msg.len = 2;
-		buf[0] = command;
-		buf[1] = val;
-		msg.buf = buf;
-		ret = adap->algo->master_xfer(adap, &msg, 1);
-	} else {
-		union i2c_smbus_data data;
-
-		data.byte = val;
-		ret = adap->algo->smbus_xfer(adap, client->addr,
-					     client->flags,
-					     I2C_SMBUS_WRITE,
-					     command,
-					     I2C_SMBUS_BYTE_DATA, &data);
-	}
-
-	return ret;
-}
-
-/*
- * Read from chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
- * as they will try to lock adapter a second time.
- */
-static int pca9541_reg_read(struct i2c_client *client, u8 command)
-{
-	struct i2c_adapter *adap = client->adapter;
-	int ret;
-	u8 val;
-
-	if (adap->algo->master_xfer) {
-		struct i2c_msg msg[2] = {
-			{
-				.addr = client->addr,
-				.flags = 0,
-				.len = 1,
-				.buf = &command
-			},
-			{
-				.addr = client->addr,
-				.flags = I2C_M_RD,
-				.len = 1,
-				.buf = &val
-			}
-		};
-		ret = adap->algo->master_xfer(adap, msg, 2);
-		if (ret == 2)
-			ret = val;
-		else if (ret >= 0)
-			ret = -EIO;
-	} else {
-		union i2c_smbus_data data;
-
-		ret = adap->algo->smbus_xfer(adap, client->addr,
-					     client->flags,
-					     I2C_SMBUS_READ,
-					     command,
-					     I2C_SMBUS_BYTE_DATA, &data);
-		if (!ret)
-			ret = data.byte;
-	}
-	return ret;
-}
-
-/*
- * Arbitration management functions
- */
-
-/* Release bus. Also reset NTESTON and BUSINIT if it was set. */
-static void pca9541_release_bus(struct i2c_client *client)
-{
-	int reg;
-
-	reg = pca9541_reg_read(client, PCA9541_CONTROL);
-	if (reg >= 0 && !busoff(reg) && mybus(reg))
-		pca9541_reg_write(client, PCA9541_CONTROL,
-				  (reg & PCA9541_CTL_NBUSON) >> 1);
-}
-
-/*
- * Arbitration is defined as a two-step process. A bus master can only activate
- * the slave bus if it owns it; otherwise it has to request ownership first.
- * This multi-step process ensures that access contention is resolved
- * gracefully.
- *
- * Bus	Ownership	Other master	Action
- * state		requested access
- * ----------------------------------------------------
- * off	-		yes		wait for arbitration timeout or
- *					for other master to drop request
- * off	no		no		take ownership
- * off	yes		no		turn on bus
- * on	yes		-		done
- * on	no		-		wait for arbitration timeout or
- *					for other master to release bus
- *
- * The main contention point occurs if the slave bus is off and both masters
- * request ownership at the same time. In this case, one master will turn on
- * the slave bus, believing that it owns it. The other master will request
- * bus ownership. Result is that the bus is turned on, and master which did
- * _not_ own the slave bus before ends up owning it.
- */
-
-/* Control commands per PCA9541 datasheet */
-static const u8 pca9541_control[16] = {
-	4, 0, 1, 5, 4, 4, 5, 5, 0, 0, 1, 1, 0, 4, 5, 1
-};
-
-/*
- * Channel arbitration
- *
- * Return values:
- *  <0: error
- *  0 : bus not acquired
- *  1 : bus acquired
- */
-static int pca9541_arbitrate(struct i2c_client *client)
-{
-	struct pca9541 *data = i2c_get_clientdata(client);
-	int reg;
-
-	reg = pca9541_reg_read(client, PCA9541_CONTROL);
-	if (reg < 0)
-		return reg;
-
-	if (busoff(reg)) {
-		int istat;
-		/*
-		 * Bus is off. Request ownership or turn it on unless
-		 * other master requested ownership.
-		 */
-		istat = pca9541_reg_read(client, PCA9541_ISTAT);
-		if (!(istat & PCA9541_ISTAT_NMYTEST)
-		    || time_is_before_eq_jiffies(data->arb_timeout)) {
-			/*
-			 * Other master did not request ownership,
-			 * or arbitration timeout expired. Take the bus.
-			 */
-			pca9541_reg_write(client,
-					  PCA9541_CONTROL,
-					  pca9541_control[reg & 0x0f]
-					  | PCA9541_CTL_NTESTON);
-			data->select_timeout = SELECT_DELAY_SHORT;
-		} else {
-			/*
-			 * Other master requested ownership.
-			 * Set extra long timeout to give it time to acquire it.
-			 */
-			data->select_timeout = SELECT_DELAY_LONG * 2;
-		}
-	} else if (mybus(reg)) {
-		/*
-		 * Bus is on, and we own it. We are done with acquisition.
-		 * Reset NTESTON and BUSINIT, then return success.
-		 */
-		if (reg & (PCA9541_CTL_NTESTON | PCA9541_CTL_BUSINIT))
-			pca9541_reg_write(client,
-					  PCA9541_CONTROL,
-					  reg & ~(PCA9541_CTL_NTESTON
-						  | PCA9541_CTL_BUSINIT));
-		return 1;
-	} else {
-		/*
-		 * Other master owns the bus.
-		 * If arbitration timeout has expired, force ownership.
-		 * Otherwise request it.
-		 */
-		data->select_timeout = SELECT_DELAY_LONG;
-		if (time_is_before_eq_jiffies(data->arb_timeout)) {
-			/* Time is up, take the bus and reset it. */
-			pca9541_reg_write(client,
-					  PCA9541_CONTROL,
-					  pca9541_control[reg & 0x0f]
-					  | PCA9541_CTL_BUSINIT
-					  | PCA9541_CTL_NTESTON);
-		} else {
-			/* Request bus ownership if needed */
-			if (!(reg & PCA9541_CTL_NTESTON))
-				pca9541_reg_write(client,
-						  PCA9541_CONTROL,
-						  reg | PCA9541_CTL_NTESTON);
-		}
-	}
-	return 0;
-}
-
-static int pca9541_select_chan(struct i2c_adapter *adap, void *client, u32 chan)
-{
-	struct pca9541 *data = i2c_get_clientdata(client);
-	int ret;
-	unsigned long timeout = jiffies + ARB2_TIMEOUT;
-		/* give up after this time */
-
-	data->arb_timeout = jiffies + ARB_TIMEOUT;
-		/* force bus ownership after this time */
-
-	do {
-		ret = pca9541_arbitrate(client);
-		if (ret)
-			return ret < 0 ? ret : 0;
-
-		if (data->select_timeout == SELECT_DELAY_SHORT)
-			udelay(data->select_timeout);
-		else
-			msleep(data->select_timeout / 1000);
-	} while (time_is_after_eq_jiffies(timeout));
-
-	return -ETIMEDOUT;
-}
-
-static int pca9541_release_chan(struct i2c_adapter *adap,
-				void *client, u32 chan)
-{
-	pca9541_release_bus(client);
-	return 0;
-}
-
-/*
- * I2C init/probing/exit functions
- */
-static int pca9541_probe(struct i2c_client *client,
-			 const struct i2c_device_id *id)
-{
-	struct i2c_adapter *adap = client->adapter;
-	struct pca954x_platform_data *pdata = client->dev.platform_data;
-	struct pca9541 *data;
-	int force;
-	int ret = -ENODEV;
-
-	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE_DATA))
-		goto err;
-
-	data = kzalloc(sizeof(struct pca9541), GFP_KERNEL);
-	if (!data) {
-		ret = -ENOMEM;
-		goto err;
-	}
-
-	i2c_set_clientdata(client, data);
-
-	/*
-	 * I2C accesses are unprotected here.
-	 * We have to lock the adapter before releasing the bus.
-	 */
-	i2c_lock_adapter(adap);
-	pca9541_release_bus(client);
-	i2c_unlock_adapter(adap);
-
-	/* Create mux adapter */
-
-	force = 0;
-	if (pdata)
-		force = pdata->modes[0].adap_id;
-	data->mux_adap = i2c_add_mux_adapter(adap, &client->dev, client,
-					     force, 0,
-					     pca9541_select_chan,
-					     pca9541_release_chan);
-
-	if (data->mux_adap == NULL) {
-		dev_err(&client->dev, "failed to register master selector\n");
-		goto exit_free;
-	}
-
-	dev_info(&client->dev, "registered master selector for I2C %s\n",
-		 client->name);
-
-	return 0;
-
-exit_free:
-	kfree(data);
-err:
-	return ret;
-}
-
-static int pca9541_remove(struct i2c_client *client)
-{
-	struct pca9541 *data = i2c_get_clientdata(client);
-
-	i2c_del_mux_adapter(data->mux_adap);
-
-	kfree(data);
-	return 0;
-}
-
-static struct i2c_driver pca9541_driver = {
-	.driver = {
-		   .name = "pca9541",
-		   .owner = THIS_MODULE,
-		   },
-	.probe = pca9541_probe,
-	.remove = pca9541_remove,
-	.id_table = pca9541_id,
-};
-
-module_i2c_driver(pca9541_driver);
-
-MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
-MODULE_DESCRIPTION("PCA9541 I2C master selector driver");
-MODULE_LICENSE("GPL v2");