* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c-viapro: Don't log nacks
i2c/pca954x: Remove __devinit and __devexit from probe and remove functions
MAINTAINERS: Add maintainer for PCA9541 I2C bus master selector driver
i2c/mux: Driver for PCA9541 I2C Master Selector
i2c: Optimize function i2c_detect()
i2c: Discard warning message on device instantiation from user-space
i2c-amd8111: Add proper error handling
i2c: Change to new flag variable
i2c: Remove unneeded inclusions of <linux/i2c-id.h>
i2c: Let i2c_parent_is_i2c_adapter return the parent adapter
i2c: Simplify i2c_parent_is_i2c_adapter
i2c-pca-platform: Change device name of request_irq
i2c: Fix Kconfig dependencies
F: drivers/leds/leds-pca9532.c
F: include/linux/leds-pca9532.h
+PCA9541 I2C BUS MASTER SELECTOR DRIVER
+M: Guenter Roeck <guenter.roeck@ericsson.com>
+L: linux-i2c@vger.kernel.org
+S: Maintained
+F: drivers/i2c/muxes/pca9541.c
+
PCA9564/PCA9665 I2C BUS DRIVER
M: Wolfram Sang <w.sang@pengutronix.de>
L: linux-i2c@vger.kernel.org
#define __NOUVEAU_I2C_H__
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/i2c-algo-bit.h>
#include "drm_dp_helper.h"
#include <drm_dp_helper.h>
#include <drm_fixed.h>
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/i2c-algo-bit.h>
struct radeon_bo;
In doubt, say Y.
config I2C_SMBUS
- tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO
+ tristate
+ prompt "SMBus-specific protocols" if !I2C_HELPER_AUTO
help
Say Y here if you want support for SMBus extensions to the I2C
specification. At the moment, the only supported extension is
obj-$(CONFIG_I2C_MUX) += i2c-mux.o
obj-y += algos/ busses/ muxes/
-ifeq ($(CONFIG_I2C_DEBUG_CORE),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG
tristate "I2C PCA 9564 interfaces"
endmenu
+
+# In automatic configuration mode, we still have to define the
+# symbols to avoid unmet dependencies.
+
+if I2C_HELPER_AUTO
+config I2C_ALGOBIT
+ tristate
+config I2C_ALGOPCF
+ tristate
+config I2C_ALGOPCA
+ tristate
+endif
obj-$(CONFIG_I2C_ALGOPCF) += i2c-algo-pcf.o
obj-$(CONFIG_I2C_ALGOPCA) += i2c-algo-pca.o
-ifeq ($(CONFIG_I2C_DEBUG_ALGO),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_I2C_DEBUG_ALGO) := -DDEBUG
obj-$(CONFIG_SCx200_ACB) += scx200_acb.o
obj-$(CONFIG_SCx200_I2C) += scx200_i2c.o
-ifeq ($(CONFIG_I2C_DEBUG_BUS),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
* ACPI 2.0 chapter 13 access of registers of the EC
*/
-static unsigned int amd_ec_wait_write(struct amd_smbus *smbus)
+static int amd_ec_wait_write(struct amd_smbus *smbus)
{
int timeout = 500;
return 0;
}
-static unsigned int amd_ec_wait_read(struct amd_smbus *smbus)
+static int amd_ec_wait_read(struct amd_smbus *smbus)
{
int timeout = 500;
return 0;
}
-static unsigned int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
+static int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
unsigned char *data)
{
int status;
return 0;
}
-static unsigned int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
+static int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
unsigned char data)
{
int status;
{
struct amd_smbus *smbus = adap->algo_data;
unsigned char protocol, len, pec, temp[2];
- int i;
+ int i, status;
protocol = (read_write == I2C_SMBUS_READ) ? AMD_SMB_PRTCL_READ
: AMD_SMB_PRTCL_WRITE;
break;
case I2C_SMBUS_BYTE:
- if (read_write == I2C_SMBUS_WRITE)
- amd_ec_write(smbus, AMD_SMB_CMD, command);
+ if (read_write == I2C_SMBUS_WRITE) {
+ status = amd_ec_write(smbus, AMD_SMB_CMD,
+ command);
+ if (status)
+ return status;
+ }
protocol |= AMD_SMB_PRTCL_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
- amd_ec_write(smbus, AMD_SMB_CMD, command);
- if (read_write == I2C_SMBUS_WRITE)
- amd_ec_write(smbus, AMD_SMB_DATA, data->byte);
+ status = amd_ec_write(smbus, AMD_SMB_CMD, command);
+ if (status)
+ return status;
+ if (read_write == I2C_SMBUS_WRITE) {
+ status = amd_ec_write(smbus, AMD_SMB_DATA,
+ data->byte);
+ if (status)
+ return status;
+ }
protocol |= AMD_SMB_PRTCL_BYTE_DATA;
break;
case I2C_SMBUS_WORD_DATA:
- amd_ec_write(smbus, AMD_SMB_CMD, command);
+ status = amd_ec_write(smbus, AMD_SMB_CMD, command);
+ if (status)
+ return status;
if (read_write == I2C_SMBUS_WRITE) {
- amd_ec_write(smbus, AMD_SMB_DATA,
- data->word & 0xff);
- amd_ec_write(smbus, AMD_SMB_DATA + 1,
- data->word >> 8);
+ status = amd_ec_write(smbus, AMD_SMB_DATA,
+ data->word & 0xff);
+ if (status)
+ return status;
+ status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
+ data->word >> 8);
+ if (status)
+ return status;
}
protocol |= AMD_SMB_PRTCL_WORD_DATA | pec;
break;
case I2C_SMBUS_BLOCK_DATA:
- amd_ec_write(smbus, AMD_SMB_CMD, command);
+ status = amd_ec_write(smbus, AMD_SMB_CMD, command);
+ if (status)
+ return status;
if (read_write == I2C_SMBUS_WRITE) {
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX);
- amd_ec_write(smbus, AMD_SMB_BCNT, len);
- for (i = 0; i < len; i++)
- amd_ec_write(smbus, AMD_SMB_DATA + i,
- data->block[i + 1]);
+ status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
+ if (status)
+ return status;
+ for (i = 0; i < len; i++) {
+ status =
+ amd_ec_write(smbus, AMD_SMB_DATA + i,
+ data->block[i + 1]);
+ if (status)
+ return status;
+ }
}
protocol |= AMD_SMB_PRTCL_BLOCK_DATA | pec;
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX);
- amd_ec_write(smbus, AMD_SMB_CMD, command);
- amd_ec_write(smbus, AMD_SMB_BCNT, len);
+ status = amd_ec_write(smbus, AMD_SMB_CMD, command);
+ if (status)
+ return status;
+ status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
+ if (status)
+ return status;
if (read_write == I2C_SMBUS_WRITE)
- for (i = 0; i < len; i++)
- amd_ec_write(smbus, AMD_SMB_DATA + i,
- data->block[i + 1]);
+ for (i = 0; i < len; i++) {
+ status =
+ amd_ec_write(smbus, AMD_SMB_DATA + i,
+ data->block[i + 1]);
+ if (status)
+ return status;
+ }
protocol |= AMD_SMB_PRTCL_I2C_BLOCK_DATA;
break;
case I2C_SMBUS_PROC_CALL:
- amd_ec_write(smbus, AMD_SMB_CMD, command);
- amd_ec_write(smbus, AMD_SMB_DATA, data->word & 0xff);
- amd_ec_write(smbus, AMD_SMB_DATA + 1, data->word >> 8);
+ status = amd_ec_write(smbus, AMD_SMB_CMD, command);
+ if (status)
+ return status;
+ status = amd_ec_write(smbus, AMD_SMB_DATA,
+ data->word & 0xff);
+ if (status)
+ return status;
+ status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
+ data->word >> 8);
+ if (status)
+ return status;
protocol = AMD_SMB_PRTCL_PROC_CALL | pec;
read_write = I2C_SMBUS_READ;
break;
case I2C_SMBUS_BLOCK_PROC_CALL:
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX - 1);
- amd_ec_write(smbus, AMD_SMB_CMD, command);
- amd_ec_write(smbus, AMD_SMB_BCNT, len);
- for (i = 0; i < len; i++)
- amd_ec_write(smbus, AMD_SMB_DATA + i,
- data->block[i + 1]);
+ status = amd_ec_write(smbus, AMD_SMB_CMD, command);
+ if (status)
+ return status;
+ status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
+ if (status)
+ return status;
+ for (i = 0; i < len; i++) {
+ status = amd_ec_write(smbus, AMD_SMB_DATA + i,
+ data->block[i + 1]);
+ if (status)
+ return status;
+ }
protocol = AMD_SMB_PRTCL_BLOCK_PROC_CALL | pec;
read_write = I2C_SMBUS_READ;
break;
return -EOPNOTSUPP;
}
- amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
- amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
+ status = amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
+ if (status)
+ return status;
+ status = amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
+ if (status)
+ return status;
- /* FIXME this discards status from ec_read(); so temp[0] will
- * hold stack garbage ... the rest of this routine will act
- * nonsensically. Ignored ec_write() status might explain
- * some such failures...
- */
- amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
+ status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
+ if (status)
+ return status;
if (~temp[0] & AMD_SMB_STS_DONE) {
udelay(500);
- amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
+ status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
+ if (status)
+ return status;
}
if (~temp[0] & AMD_SMB_STS_DONE) {
msleep(1);
- amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
+ status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
+ if (status)
+ return status;
}
if ((~temp[0] & AMD_SMB_STS_DONE) || (temp[0] & AMD_SMB_STS_STATUS))
switch (size) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
- amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
+ status = amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
+ if (status)
+ return status;
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
- amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
- amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
+ status = amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
+ if (status)
+ return status;
+ status = amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
+ if (status)
+ return status;
data->word = (temp[1] << 8) | temp[0];
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_PROC_CALL:
- amd_ec_read(smbus, AMD_SMB_BCNT, &len);
+ status = amd_ec_read(smbus, AMD_SMB_BCNT, &len);
+ if (status)
+ return status;
len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
case I2C_SMBUS_I2C_BLOCK_DATA:
- for (i = 0; i < len; i++)
- amd_ec_read(smbus, AMD_SMB_DATA + i,
- data->block + i + 1);
+ for (i = 0; i < len; i++) {
+ status = amd_ec_read(smbus, AMD_SMB_DATA + i,
+ data->block + i + 1);
+ if (status)
+ return status;
+ }
data->block[0] = len;
break;
}
#include <asm/irq.h>
#include <linux/io.h>
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/of_platform.h>
#include <linux/of_i2c.h>
#include <linux/module.h>
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
if (irq) {
ret = request_irq(irq, i2c_pca_pf_handler,
- IRQF_TRIGGER_FALLING, i2c->adap.name, i2c);
+ IRQF_TRIGGER_FALLING, pdev->name, i2c);
if (ret)
goto e_reqirq;
}
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
}
if (temp & 0x04) {
- int read = inb_p(SMBHSTADD) & 0x01;
result = -ENXIO;
- /* The quick and receive byte commands are used to probe
- for chips, so errors are expected, and we don't want
- to frighten the user. */
- if (!((size == VT596_QUICK && !read) ||
- (size == VT596_BYTE && read)))
- dev_err(&vt596_adapter.dev, "Transaction error!\n");
+ dev_dbg(&vt596_adapter.dev, "No response\n");
}
/* Resetting status register */
/* walk up mux tree */
static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
int result;
result = device_for_each_child(&adapter->dev, &addr,
__i2c_check_addr_busy);
- if (!result && i2c_parent_is_i2c_adapter(adapter))
- result = i2c_check_mux_parents(
- to_i2c_adapter(adapter->dev.parent), addr);
+ if (!result && parent)
+ result = i2c_check_mux_parents(parent, addr);
return result;
}
static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
int result = 0;
- if (i2c_parent_is_i2c_adapter(adapter))
- result = i2c_check_mux_parents(
- to_i2c_adapter(adapter->dev.parent), addr);
+ if (parent)
+ result = i2c_check_mux_parents(parent, addr);
if (!result)
result = device_for_each_child(&adapter->dev, &addr,
*/
void i2c_lock_adapter(struct i2c_adapter *adapter)
{
- if (i2c_parent_is_i2c_adapter(adapter))
- i2c_lock_adapter(to_i2c_adapter(adapter->dev.parent));
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+ if (parent)
+ i2c_lock_adapter(parent);
else
rt_mutex_lock(&adapter->bus_lock);
}
*/
static int i2c_trylock_adapter(struct i2c_adapter *adapter)
{
- if (i2c_parent_is_i2c_adapter(adapter))
- return i2c_trylock_adapter(to_i2c_adapter(adapter->dev.parent));
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+ if (parent)
+ return i2c_trylock_adapter(parent);
else
return rt_mutex_trylock(&adapter->bus_lock);
}
*/
void i2c_unlock_adapter(struct i2c_adapter *adapter)
{
- if (i2c_parent_is_i2c_adapter(adapter))
- i2c_unlock_adapter(to_i2c_adapter(adapter->dev.parent));
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+ if (parent)
+ i2c_unlock_adapter(parent);
else
rt_mutex_unlock(&adapter->bus_lock);
}
char *blank, end;
int res;
- dev_warn(dev, "The new_device interface is still experimental "
- "and may change in a near future\n");
memset(&info, 0, sizeof(struct i2c_board_info));
blank = strchr(buf, ' ');
if (!driver->detect || !address_list)
return 0;
+ /* Stop here if the classes do not match */
+ if (!(adapter->class & driver->class))
+ return 0;
+
/* Set up a temporary client to help detect callback */
temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
if (!temp_client)
return -ENOMEM;
temp_client->adapter = adapter;
- /* Stop here if the classes do not match */
- if (!(adapter->class & driver->class))
- goto exit_free;
-
for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
"addr 0x%02x\n", adap_id, address_list[i]);
temp_client->addr = address_list[i];
err = i2c_detect_address(temp_client, driver);
- if (err)
- goto exit_free;
+ if (unlikely(err))
+ break;
}
- exit_free:
kfree(temp_client);
return err;
}
/* walk up mux tree */
static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
int result;
result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
-
- if (!result && i2c_parent_is_i2c_adapter(adapter))
- result = i2cdev_check_mux_parents(
- to_i2c_adapter(adapter->dev.parent), addr);
+ if (!result && parent)
+ result = i2cdev_check_mux_parents(parent, addr);
return result;
}
driver bound to it, as NOT busy. */
static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
int result = 0;
- if (i2c_parent_is_i2c_adapter(adapter))
- result = i2cdev_check_mux_parents(
- to_i2c_adapter(adapter->dev.parent), addr);
+ if (parent)
+ result = i2cdev_check_mux_parents(parent, addr);
if (!result)
result = device_for_each_child(&adapter->dev, &addr,
menu "Multiplexer I2C Chip support"
depends on I2C_MUX
+config I2C_MUX_PCA9541
+ tristate "NXP PCA9541 I2C Master Selector"
+ depends on EXPERIMENTAL
+ help
+ If you say yes here you get support for the NXP PCA9541
+ I2C Master Selector.
+
+ This driver can also be built as a module. If so, the module
+ will be called pca9541.
+
config I2C_MUX_PCA954x
tristate "Philips PCA954x I2C Mux/switches"
depends on EXPERIMENTAL
#
# Makefile for multiplexer I2C chip drivers.
+obj-$(CONFIG_I2C_MUX_PCA9541) += pca9541.o
obj-$(CONFIG_I2C_MUX_PCA954x) += pca954x.o
-ifeq ($(CONFIG_I2C_DEBUG_BUS),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
+ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
--- /dev/null
+/*
+ * 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, 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,
+};
+
+static int __init pca9541_init(void)
+{
+ return i2c_add_driver(&pca9541_driver);
+}
+
+static void __exit pca9541_exit(void)
+{
+ i2c_del_driver(&pca9541_driver);
+}
+
+module_init(pca9541_init);
+module_exit(pca9541_exit);
+
+MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
+MODULE_DESCRIPTION("PCA9541 I2C master selector driver");
+MODULE_LICENSE("GPL v2");
/*
* I2C init/probing/exit functions
*/
-static int __devinit pca954x_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+static int pca954x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
{
struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
struct pca954x_platform_data *pdata = client->dev.platform_data;
return ret;
}
-static int __devexit pca954x_remove(struct i2c_client *client)
+static int pca954x_remove(struct i2c_client *client)
{
struct pca954x *data = i2c_get_clientdata(client);
const struct chip_desc *chip = &chips[data->type];
.owner = THIS_MODULE,
},
.probe = pca954x_probe,
- .remove = __devexit_p(pca954x_remove),
+ .remove = pca954x_remove,
.id_table = pca954x_id,
};
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/i2c-algo-bit.h>
#include <asm/io.h>
#include <linux/agp_backend.h>
#include <linux/fb.h>
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/i2c-algo-bit.h>
#include <video/vga.h>
#include <linux/fb.h>
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/i2c-algo-bit.h>
#include <asm/io.h>
#define __SAVAGEFB_H__
#include <linux/i2c.h>
-#include <linux/i2c-id.h>
#include <linux/i2c-algo-bit.h>
#include <linux/mutex.h>
#include <video/vga.h>
dev_set_drvdata(&dev->dev, data);
}
-static inline int i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
+static inline struct i2c_adapter *
+i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
{
- return adapter->dev.parent != NULL
- && adapter->dev.parent->bus == &i2c_bus_type
- && adapter->dev.parent->type == &i2c_adapter_type;
+ struct device *parent = adapter->dev.parent;
+
+ if (parent != NULL && parent->type == &i2c_adapter_type)
+ return to_i2c_adapter(parent);
+ else
+ return NULL;
}
/* Adapter locking functions, exported for shared pin cases */
git.openpandora.org / pandora-kernel.git / commitdiff