From 665a96b70bfccec6eab2e8d3c770e357e14294ea Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 10 Jan 2011 22:11:22 +0100 Subject: i2c-i801: Include Commit 5a0e3ad6af8660be21ca98a971cd00f331318c05 added direct inclusion of to those source files that appeared to need it, but somehow missed this. On most architectures is still indirectly included, but there are exceptions such as alpha. Signed-off-by: Ben Hutchings Signed-off-by: Jean Delvare --- drivers/i2c/busses/i2c-i801.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 02835ce7ff4b..7979aef7ee7b 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -72,6 +72,7 @@ #include #include #include +#include /* I801 SMBus address offsets */ #define SMBHSTSTS(p) (0 + (p)->smba) -- cgit v1.2.2 From b18a5c80eb2e7e9c72d23f1960b09d78ddf7e5b0 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Mon, 10 Jan 2011 22:11:22 +0100 Subject: i2c-nforce2: Remove unnecessary cast of pci_get_drvdata Signed-off-by: Joe Perches Signed-off-by: Jean Delvare --- drivers/i2c/busses/i2c-nforce2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/busses/i2c-nforce2.c b/drivers/i2c/busses/i2c-nforce2.c index a605a5029cfe..ff1e127dfea8 100644 --- a/drivers/i2c/busses/i2c-nforce2.c +++ b/drivers/i2c/busses/i2c-nforce2.c @@ -432,7 +432,7 @@ static int __devinit nforce2_probe(struct pci_dev *dev, const struct pci_device_ static void __devexit nforce2_remove(struct pci_dev *dev) { - struct nforce2_smbus *smbuses = (void*) pci_get_drvdata(dev); + struct nforce2_smbus *smbuses = pci_get_drvdata(dev); nforce2_set_reference(NULL); if (smbuses[0].base) { -- cgit v1.2.2 From 92ed1a76ca31774eb27de14b2215841367c68056 Mon Sep 17 00:00:00 2001 From: Peter Korsgaard Date: Mon, 10 Jan 2011 22:11:23 +0100 Subject: i2c: Add generic I2C multiplexer using GPIO API Add an i2c mux driver providing access to i2c bus segments using a hardware MUX sitting on a master bus and controlled through gpio pins. E.G. something like: ---------- ---------- Bus segment 1 - - - - - | | SCL/SDA | |-------------- | | | |------------| | | | | | Bus segment 2 | | | Linux | GPIO 1..N | MUX |--------------- Devices | |------------| | | | | | | | Bus segment M | | | |---------------| | ---------- ---------- - - - - - SCL/SDA of the master I2C bus is multiplexed to bus segment 1..M according to the settings of the GPIO pins 1..N. Signed-off-by: Peter Korsgaard Signed-off-by: Jean Delvare --- drivers/i2c/muxes/Kconfig | 12 +++ drivers/i2c/muxes/Makefile | 1 + drivers/i2c/muxes/gpio-i2cmux.c | 184 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 197 insertions(+) create mode 100644 drivers/i2c/muxes/gpio-i2cmux.c (limited to 'drivers/i2c') diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig index 4d91d80bfd23..90b7a0163899 100644 --- a/drivers/i2c/muxes/Kconfig +++ b/drivers/i2c/muxes/Kconfig @@ -5,6 +5,18 @@ menu "Multiplexer I2C Chip support" depends on I2C_MUX +config I2C_MUX_GPIO + tristate "GPIO-based I2C multiplexer" + depends on GENERIC_GPIO + help + If you say yes to this option, support will be included for a + GPIO based I2C multiplexer. This driver provides access to + I2C busses connected through a MUX, which is controlled + through GPIO pins. + + This driver can also be built as a module. If so, the module + will be called gpio-i2cmux. + config I2C_MUX_PCA9541 tristate "NXP PCA9541 I2C Master Selector" depends on EXPERIMENTAL diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile index d743806d9b42..4640436ea61f 100644 --- a/drivers/i2c/muxes/Makefile +++ b/drivers/i2c/muxes/Makefile @@ -1,6 +1,7 @@ # # Makefile for multiplexer I2C chip drivers. +obj-$(CONFIG_I2C_MUX_GPIO) += gpio-i2cmux.o obj-$(CONFIG_I2C_MUX_PCA9541) += pca9541.o obj-$(CONFIG_I2C_MUX_PCA954x) += pca954x.o diff --git a/drivers/i2c/muxes/gpio-i2cmux.c b/drivers/i2c/muxes/gpio-i2cmux.c new file mode 100644 index 000000000000..7b6ce624cd6e --- /dev/null +++ b/drivers/i2c/muxes/gpio-i2cmux.c @@ -0,0 +1,184 @@ +/* + * I2C multiplexer using GPIO API + * + * Peter Korsgaard + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +struct gpiomux { + struct i2c_adapter *parent; + struct i2c_adapter **adap; /* child busses */ + struct gpio_i2cmux_platform_data data; +}; + +static void gpiomux_set(const struct gpiomux *mux, unsigned val) +{ + int i; + + for (i = 0; i < mux->data.n_gpios; i++) + gpio_set_value(mux->data.gpios[i], val & (1 << i)); +} + +static int gpiomux_select(struct i2c_adapter *adap, void *data, u32 chan) +{ + struct gpiomux *mux = data; + + gpiomux_set(mux, mux->data.values[chan]); + + return 0; +} + +static int gpiomux_deselect(struct i2c_adapter *adap, void *data, u32 chan) +{ + struct gpiomux *mux = data; + + gpiomux_set(mux, mux->data.idle); + + return 0; +} + +static int __devinit gpiomux_probe(struct platform_device *pdev) +{ + struct gpiomux *mux; + struct gpio_i2cmux_platform_data *pdata; + struct i2c_adapter *parent; + int (*deselect) (struct i2c_adapter *, void *, u32); + unsigned initial_state; + int i, ret; + + pdata = pdev->dev.platform_data; + if (!pdata) { + dev_err(&pdev->dev, "Missing platform data\n"); + return -ENODEV; + } + + parent = i2c_get_adapter(pdata->parent); + if (!parent) { + dev_err(&pdev->dev, "Parent adapter (%d) not found\n", + pdata->parent); + return -ENODEV; + } + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) { + ret = -ENOMEM; + goto alloc_failed; + } + + mux->parent = parent; + mux->data = *pdata; + mux->adap = kzalloc(sizeof(struct i2c_adapter *) * pdata->n_values, + GFP_KERNEL); + if (!mux->adap) { + ret = -ENOMEM; + goto alloc_failed2; + } + + if (pdata->idle != GPIO_I2CMUX_NO_IDLE) { + initial_state = pdata->idle; + deselect = gpiomux_deselect; + } else { + initial_state = pdata->values[0]; + deselect = NULL; + } + + for (i = 0; i < pdata->n_gpios; i++) { + ret = gpio_request(pdata->gpios[i], "gpio-i2cmux"); + if (ret) + goto err_request_gpio; + gpio_direction_output(pdata->gpios[i], + initial_state & (1 << i)); + } + + for (i = 0; i < pdata->n_values; i++) { + u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0; + + mux->adap[i] = i2c_add_mux_adapter(parent, mux, nr, i, + gpiomux_select, deselect); + if (!mux->adap[i]) { + ret = -ENODEV; + dev_err(&pdev->dev, "Failed to add adapter %d\n", i); + goto add_adapter_failed; + } + } + + dev_info(&pdev->dev, "%d port mux on %s adapter\n", + pdata->n_values, parent->name); + + platform_set_drvdata(pdev, mux); + + return 0; + +add_adapter_failed: + for (; i > 0; i--) + i2c_del_mux_adapter(mux->adap[i - 1]); + i = pdata->n_gpios; +err_request_gpio: + for (; i > 0; i--) + gpio_free(pdata->gpios[i - 1]); + kfree(mux->adap); +alloc_failed2: + kfree(mux); +alloc_failed: + i2c_put_adapter(parent); + + return ret; +} + +static int __devexit gpiomux_remove(struct platform_device *pdev) +{ + struct gpiomux *mux = platform_get_drvdata(pdev); + int i; + + for (i = 0; i < mux->data.n_values; i++) + i2c_del_mux_adapter(mux->adap[i]); + + for (i = 0; i < mux->data.n_gpios; i++) + gpio_free(mux->data.gpios[i]); + + platform_set_drvdata(pdev, NULL); + i2c_put_adapter(mux->parent); + kfree(mux->adap); + kfree(mux); + + return 0; +} + +static struct platform_driver gpiomux_driver = { + .probe = gpiomux_probe, + .remove = __devexit_p(gpiomux_remove), + .driver = { + .owner = THIS_MODULE, + .name = "gpio-i2cmux", + }, +}; + +static int __init gpiomux_init(void) +{ + return platform_driver_register(&gpiomux_driver); +} + +static void __exit gpiomux_exit(void) +{ + platform_driver_unregister(&gpiomux_driver); +} + +module_init(gpiomux_init); +module_exit(gpiomux_exit); + +MODULE_DESCRIPTION("GPIO-based I2C multiplexer driver"); +MODULE_AUTHOR("Peter Korsgaard "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:gpio-i2cmux"); -- cgit v1.2.2 From f451171c5ac829e55581c81caf2cb01e1c0a5c5f Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 10 Jan 2011 22:11:23 +0100 Subject: i2c-algo-bit: Refactor adapter registration Use a function pointer to decide whether to call i2c_add_adapter or i2c_add_numbered_adapter. This makes the code more compact than the current strategy of having the common code in a separate function. Signed-off-by: Jean Delvare --- drivers/i2c/algos/i2c-algo-bit.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index a39e6cff86e7..938170b8998b 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -600,7 +600,8 @@ static const struct i2c_algorithm i2c_bit_algo = { /* * registering functions to load algorithms at runtime */ -static int i2c_bit_prepare_bus(struct i2c_adapter *adap) +static int __i2c_bit_add_bus(struct i2c_adapter *adap, + int (*add_adapter)(struct i2c_adapter *)) { struct i2c_algo_bit_data *bit_adap = adap->algo_data; @@ -614,30 +615,18 @@ static int i2c_bit_prepare_bus(struct i2c_adapter *adap) adap->algo = &i2c_bit_algo; adap->retries = 3; - return 0; + return add_adapter(adap); } int i2c_bit_add_bus(struct i2c_adapter *adap) { - int err; - - err = i2c_bit_prepare_bus(adap); - if (err) - return err; - - return i2c_add_adapter(adap); + return __i2c_bit_add_bus(adap, i2c_add_adapter); } EXPORT_SYMBOL(i2c_bit_add_bus); int i2c_bit_add_numbered_bus(struct i2c_adapter *adap) { - int err; - - err = i2c_bit_prepare_bus(adap); - if (err) - return err; - - return i2c_add_numbered_adapter(adap); + return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter); } EXPORT_SYMBOL(i2c_bit_add_numbered_bus); -- cgit v1.2.2 From af5a60baaee66e2f891dbb9a8519ca28ab7da7cd Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 10 Jan 2011 22:11:23 +0100 Subject: i2c-algo-bit: Complain about masters which can't read SCL The I2C specification explicitly describes both SDA and SCL as bidirectional lines. An I2C master with a read-only SCL is thus not compliant. If a slow slave stretches the clock, errors will happen, so the bus can't be considered as reliable. Signed-off-by: Jean Delvare --- drivers/i2c/algos/i2c-algo-bit.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 938170b8998b..38319a69bd0a 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -604,9 +604,10 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap, int (*add_adapter)(struct i2c_adapter *)) { struct i2c_algo_bit_data *bit_adap = adap->algo_data; + int ret; if (bit_test) { - int ret = test_bus(bit_adap, adap->name); + ret = test_bus(bit_adap, adap->name); if (ret < 0) return -ENODEV; } @@ -615,7 +616,16 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap, adap->algo = &i2c_bit_algo; adap->retries = 3; - return add_adapter(adap); + ret = add_adapter(adap); + if (ret < 0) + return ret; + + /* Complain if SCL can't be read */ + if (bit_adap->getscl == NULL) { + dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n"); + dev_warn(&adap->dev, "Bus may be unreliable\n"); + } + return 0; } int i2c_bit_add_bus(struct i2c_adapter *adap) -- cgit v1.2.2 From 0cc43a1806f078f7fd414850d8f1f1761696e4af Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 10 Jan 2011 22:11:23 +0100 Subject: i2c: Constify i2c_client where possible Helper functions for I2C and SMBus transactions don't modify the i2c_client that is passed to them, so it can be marked const. Signed-off-by: Jean Delvare --- drivers/i2c/i2c-core.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) (limited to 'drivers/i2c') diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 6b4cc567645b..c7db6980e3a3 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1362,7 +1362,7 @@ EXPORT_SYMBOL(i2c_transfer); * * Returns negative errno, or else the number of bytes written. */ -int i2c_master_send(struct i2c_client *client, const char *buf, int count) +int i2c_master_send(const struct i2c_client *client, const char *buf, int count) { int ret; struct i2c_adapter *adap = client->adapter; @@ -1389,7 +1389,7 @@ EXPORT_SYMBOL(i2c_master_send); * * Returns negative errno, or else the number of bytes read. */ -int i2c_master_recv(struct i2c_client *client, char *buf, int count) +int i2c_master_recv(const struct i2c_client *client, char *buf, int count) { struct i2c_adapter *adap = client->adapter; struct i2c_msg msg; @@ -1679,7 +1679,7 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) * This executes the SMBus "receive byte" protocol, returning negative errno * else the byte received from the device. */ -s32 i2c_smbus_read_byte(struct i2c_client *client) +s32 i2c_smbus_read_byte(const struct i2c_client *client) { union i2c_smbus_data data; int status; @@ -1699,7 +1699,7 @@ EXPORT_SYMBOL(i2c_smbus_read_byte); * This executes the SMBus "send byte" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) +s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) { return i2c_smbus_xfer(client->adapter, client->addr, client->flags, I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); @@ -1714,7 +1714,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte); * This executes the SMBus "read byte" protocol, returning negative errno * else a data byte received from the device. */ -s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) +s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) { union i2c_smbus_data data; int status; @@ -1735,7 +1735,8 @@ EXPORT_SYMBOL(i2c_smbus_read_byte_data); * This executes the SMBus "write byte" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) +s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, + u8 value) { union i2c_smbus_data data; data.byte = value; @@ -1753,7 +1754,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte_data); * This executes the SMBus "read word" protocol, returning negative errno * else a 16-bit unsigned "word" received from the device. */ -s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) +s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) { union i2c_smbus_data data; int status; @@ -1774,7 +1775,8 @@ EXPORT_SYMBOL(i2c_smbus_read_word_data); * This executes the SMBus "write word" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) +s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, + u16 value) { union i2c_smbus_data data; data.word = value; @@ -1793,7 +1795,8 @@ EXPORT_SYMBOL(i2c_smbus_write_word_data); * This executes the SMBus "process call" protocol, returning negative errno * else a 16-bit unsigned "word" received from the device. */ -s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) +s32 i2c_smbus_process_call(const struct i2c_client *client, u8 command, + u16 value) { union i2c_smbus_data data; int status; @@ -1821,7 +1824,7 @@ EXPORT_SYMBOL(i2c_smbus_process_call); * support this; its emulation through I2C messaging relies on a specific * mechanism (I2C_M_RECV_LEN) which may not be implemented. */ -s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, u8 *values) { union i2c_smbus_data data; @@ -1848,7 +1851,7 @@ EXPORT_SYMBOL(i2c_smbus_read_block_data); * This executes the SMBus "block write" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values) { union i2c_smbus_data data; @@ -1864,7 +1867,7 @@ s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, EXPORT_SYMBOL(i2c_smbus_write_block_data); /* Returns the number of read bytes */ -s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, u8 *values) { union i2c_smbus_data data; @@ -1884,7 +1887,7 @@ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, } EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); -s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values) { union i2c_smbus_data data; -- cgit v1.2.2