On 05/01/2012 12:23 PM, Stephen Warren wrote: > From: Stephen Warren <[email protected]> > > This is useful for SoCs whose I2C module's signals can be routed to > different sets of pins at run-time, using the pinctrl API. > > +-----+ +-----+ > | dev | | dev | > +------------------------+ +-----+ +-----+ > | SoC | | | > | /----|------+--------+ > | +---+ +------+ | child bus A, on first set of pins > | |I2C|---|Pinmux| | > | +---+ +------+ | child bus B, on second set of pins > | \----|------+--------+--------+ > | | | | | > +------------------------+ +-----+ +-----+ +-----+ > | dev | | dev | | dev | > +-----+ +-----+ +-----+ >
Such a pretty drawing, I think it deserves to be in the binding doc. Otherwise, looks good to me: Acked-by: Rob Herring <[email protected]> Sorry for the delayed response. Rob > Signed-off-by: Stephen Warren <[email protected]> > Acked-by: Linus Walleij <[email protected]> > --- > v3: Renamed pinctrl-i2cmux.c to i2c-mux-pinctrl.c to match recent changes > to other I2C mux files. > v2: Rebase onto David Daney's i2c-mux OF support, including slight binding > changes. Add more error messages. > > squash pinctrl i2c mux > --- > .../devicetree/bindings/i2c/i2c-mux-pinctrl.txt | 79 ++++++ > drivers/i2c/muxes/Kconfig | 12 + > drivers/i2c/muxes/Makefile | 1 + > drivers/i2c/muxes/i2c-mux-pinctrl.c | 279 > ++++++++++++++++++++ > include/linux/i2c-mux-pinctrl.h | 41 +++ > 5 files changed, 412 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt > create mode 100644 drivers/i2c/muxes/i2c-mux-pinctrl.c > create mode 100644 include/linux/i2c-mux-pinctrl.h > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt > b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt > new file mode 100644 > index 0000000..b10e268 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt > @@ -0,0 +1,79 @@ > +Pinctrl-based I2C Bus Mux > + > +This binding describes an I2C bus multiplexer that uses pin multiplexing to > +route the I2C signals, and represents the pin multiplexing configuration > +using the pinctrl device tree bindings. > + > +Required properties: > +- compatible: i2c-mux-pinctrl > +- i2c-parent: The phandle of the I2C bus that this multiplexer's master-side > + port is connected to. > + > +Also required are: > + > +* Standard pinctrl properties that specify the pin mux state for each child > + bus. See ../pinctrl/pinctrl-bindings.txt. > + > +* Standard I2C mux properties. See mux.txt in this directory. > + > +* I2C child bus nodes. See mux.txt in this directory. > + > +For each named state defined in the pinctrl-names property, an I2C child bus > +will be created. I2C child bus numbers are assigned based on the index into > +the pinctrl-names property. > + > +The only exception is that no bus will be created for a state named "idle". > If > +such a state is defined, it must be the last entry in pinctrl-names. For > +example: > + > + pinctrl-names = "ddc", "pta", "idle" -> ddc = bus 0, pta = bus 1 > + pinctrl-names = "ddc", "idle", "pta" -> Invalid ("idle" not last) > + pinctrl-names = "idle", "ddc", "pta" -> Invalid ("idle" not last) > + > +Whenever an access is made to a device on a child bus, the relevant pinctrl > +state will be programmed into hardware. > + > +If an idle state is defined, whenever an access is not being made to a device > +on a child bus, the idle pinctrl state will be programmed into hardware. > + > +If an idle state is not defined, the most recently used pinctrl state will be > +left programmed into hardware whenever no access is being made of a device on > +a child bus. > + > +Example: > + > + i2cmux { > + compatible = "i2c-mux-pinctrl"; > + #address-cells = <1>; > + #size-cells = <0>; > + > + i2c-parent = <&i2c1>; > + > + pinctrl-names = "ddc", "pta", "idle"; > + pinctrl-0 = <&state_i2cmux_ddc>; > + pinctrl-1 = <&state_i2cmux_pta>; > + pinctrl-2 = <&state_i2cmux_idle>; > + > + i2c@0 { > + reg = <0>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + eeprom { > + compatible = "eeprom"; > + reg = <0x50>; > + }; > + }; > + > + i2c@1 { > + reg = <1>; > + #address-cells = <1>; > + #size-cells = <0>; > + > + eeprom { > + compatible = "eeprom"; > + reg = <0x50>; > + }; > + }; > + }; > + > diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig > index e14a420..c237a1b 100644 > --- a/drivers/i2c/muxes/Kconfig > +++ b/drivers/i2c/muxes/Kconfig > @@ -37,4 +37,16 @@ config I2C_MUX_PCA954x > This driver can also be built as a module. If so, the module > will be called i2c-mux-pca954x. > > +config I2C_MUX_PINCTRL > + tristate "pinctrl-based I2C multiplexer" > + depends on PINCTRL > + help > + If you say yes to this option, support will be included for an I2C > + multiplexer that uses the pinctrl subsystem, i.e. pin multiplexing. > + This is useful for SoCs whose I2C module's signals can be routed to > + different sets of pins at run-time. > + > + This driver can also be built as a module. If so, the module will be > + called pinctrl-i2cmux. > + > endmenu > diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile > index 0868335..0e2a3cd 100644 > --- a/drivers/i2c/muxes/Makefile > +++ b/drivers/i2c/muxes/Makefile > @@ -4,5 +4,6 @@ > obj-$(CONFIG_I2C_MUX_GPIO) += gpio-i2cmux.o > obj-$(CONFIG_I2C_MUX_PCA9541) += i2c-mux-pca9541.o > obj-$(CONFIG_I2C_MUX_PCA954x) += i2c-mux-pca954x.o > +obj-$(CONFIG_I2C_MUX_PINCTRL) += i2c-mux-pinctrl.o > > ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG > diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c > b/drivers/i2c/muxes/i2c-mux-pinctrl.c > new file mode 100644 > index 0000000..46a6697 > --- /dev/null > +++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c > @@ -0,0 +1,279 @@ > +/* > + * I2C multiplexer using pinctrl API > + * > + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/i2c.h> > +#include <linux/i2c-mux.h> > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/of_i2c.h> > +#include <linux/pinctrl/consumer.h> > +#include <linux/i2c-mux-pinctrl.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > + > +struct i2c_mux_pinctrl { > + struct device *dev; > + struct i2c_mux_pinctrl_platform_data *pdata; > + struct pinctrl *pinctrl; > + struct pinctrl_state **states; > + struct pinctrl_state *state_idle; > + struct i2c_adapter *parent; > + struct i2c_adapter **busses; > +}; > + > +static int i2c_mux_pinctrl_select(struct i2c_adapter *adap, void *data, > + u32 chan) > +{ > + struct i2c_mux_pinctrl *mux = data; > + > + return pinctrl_select_state(mux->pinctrl, mux->states[chan]); > +} > + > +static int i2c_mux_pinctrl_deselect(struct i2c_adapter *adap, void *data, > + u32 chan) > +{ > + struct i2c_mux_pinctrl *mux = data; > + > + return pinctrl_select_state(mux->pinctrl, mux->state_idle); > +} > + > +#ifdef CONFIG_OF > +static int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux, > + struct platform_device *pdev) > +{ > + struct device_node *np = pdev->dev.of_node; > + int num_names, i, ret; > + struct device_node *adapter_np; > + struct i2c_adapter *adapter; > + > + if (!np) > + return 0; > + > + mux->pdata = devm_kzalloc(&pdev->dev, sizeof(*mux->pdata), GFP_KERNEL); > + if (!mux->pdata) { > + dev_err(mux->dev, > + "Cannot allocate i2c_mux_pinctrl_platform_data\n"); > + return -ENOMEM; > + } > + > + num_names = of_property_count_strings(np, "pinctrl-names"); > + if (num_names < 0) { > + dev_err(mux->dev, "Cannot parse pinctrl-names: %d\n", > + num_names); > + return num_names; > + } > + > + mux->pdata->pinctrl_states = devm_kzalloc(&pdev->dev, > + sizeof(*mux->pdata->pinctrl_states) * num_names, > + GFP_KERNEL); > + if (!mux->pdata->pinctrl_states) { > + dev_err(mux->dev, "Cannot allocate pinctrl_states\n"); > + return -ENOMEM; > + } > + > + for (i = 0; i < num_names; i++) { > + ret = of_property_read_string_index(np, "pinctrl-names", i, > + &mux->pdata->pinctrl_states[mux->pdata->bus_count]); > + if (ret < 0) { > + dev_err(mux->dev, "Cannot parse pinctrl-names: %d\n", > + ret); > + return ret; > + } > + if (!strcmp(mux->pdata->pinctrl_states[mux->pdata->bus_count], > + "idle")) { > + if (i != num_names - 1) { > + dev_err(mux->dev, "idle state must be last\n"); > + return -EINVAL; > + } > + mux->pdata->pinctrl_state_idle = "idle"; > + } else { > + mux->pdata->bus_count++; > + } > + } > + > + adapter_np = of_parse_phandle(np, "i2c-parent", 0); > + if (!adapter_np) { > + dev_err(mux->dev, "Cannot parse i2c-parent\n"); > + return -ENODEV; > + } > + adapter = of_find_i2c_adapter_by_node(adapter_np); > + if (!adapter) { > + dev_err(mux->dev, "Cannot find parent bus\n"); > + return -ENODEV; > + } > + mux->pdata->parent_bus_num = i2c_adapter_id(adapter); > + put_device(&adapter->dev); > + > + return 0; > +} > +#else > +static inline int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux, > + struct platform_device *pdev) > +{ > + return 0; > +} > +#endif > + > +static int __devinit i2c_mux_pinctrl_probe(struct platform_device *pdev) > +{ > + struct i2c_mux_pinctrl *mux; > + int (*deselect)(struct i2c_adapter *, void *, u32); > + int i, ret; > + > + mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL); > + if (!mux) { > + dev_err(&pdev->dev, "Cannot allocate i2c_mux_pinctrl\n"); > + ret = -ENOMEM; > + goto err; > + } > + platform_set_drvdata(pdev, mux); > + > + mux->dev = &pdev->dev; > + > + mux->pdata = pdev->dev.platform_data; > + if (!mux->pdata) { > + ret = i2c_mux_pinctrl_parse_dt(mux, pdev); > + if (ret < 0) > + goto err; > + } > + if (!mux->pdata) { > + dev_err(&pdev->dev, "Missing platform data\n"); > + ret = -ENODEV; > + goto err; > + } > + > + mux->states = devm_kzalloc(&pdev->dev, > + sizeof(*mux->states) * mux->pdata->bus_count, > + GFP_KERNEL); > + if (!mux->states) { > + dev_err(&pdev->dev, "Cannot allocate states\n"); > + ret = -ENOMEM; > + goto err; > + } > + > + mux->busses = devm_kzalloc(&pdev->dev, > + sizeof(mux->busses) * mux->pdata->bus_count, > + GFP_KERNEL); > + if (!mux->states) { > + dev_err(&pdev->dev, "Cannot allocate busses\n"); > + ret = -ENOMEM; > + goto err; > + } > + > + mux->pinctrl = devm_pinctrl_get(&pdev->dev); > + if (IS_ERR(mux->pinctrl)) { > + ret = PTR_ERR(mux->pinctrl); > + dev_err(&pdev->dev, "Cannot get pinctrl: %d\n", ret); > + goto err; > + } > + for (i = 0; i < mux->pdata->bus_count; i++) { > + mux->states[i] = pinctrl_lookup_state(mux->pinctrl, > + mux->pdata->pinctrl_states[i]); > + if (IS_ERR(mux->states[i])) { > + ret = PTR_ERR(mux->states[i]); > + dev_err(&pdev->dev, > + "Cannot look up pinctrl state %s: %d\n", > + mux->pdata->pinctrl_states[i], ret); > + goto err; > + } > + } > + if (mux->pdata->pinctrl_state_idle) { > + mux->state_idle = pinctrl_lookup_state(mux->pinctrl, > + mux->pdata->pinctrl_state_idle); > + if (IS_ERR(mux->state_idle)) { > + ret = PTR_ERR(mux->state_idle); > + dev_err(&pdev->dev, > + "Cannot look up pinctrl state %s: %d\n", > + mux->pdata->pinctrl_state_idle, ret); > + goto err; > + } > + > + deselect = i2c_mux_pinctrl_deselect; > + } else { > + deselect = NULL; > + } > + > + mux->parent = i2c_get_adapter(mux->pdata->parent_bus_num); > + if (!mux->parent) { > + dev_err(&pdev->dev, "Parent adapter (%d) not found\n", > + mux->pdata->parent_bus_num); > + ret = -ENODEV; > + goto err; > + } > + > + for (i = 0; i < mux->pdata->bus_count; i++) { > + u32 bus = mux->pdata->base_bus_num ? > + (mux->pdata->base_bus_num + i) : 0; > + > + mux->busses[i] = i2c_add_mux_adapter(mux->parent, &pdev->dev, > + mux, bus, i, > + i2c_mux_pinctrl_select, > + deselect); > + if (!mux->busses[i]) { > + ret = -ENODEV; > + dev_err(&pdev->dev, "Failed to add adapter %d\n", i); > + goto err_del_adapter; > + } > + } > + > + return 0; > + > +err_del_adapter: > + for (; i > 0; i--) > + i2c_del_mux_adapter(mux->busses[i - 1]); > + i2c_put_adapter(mux->parent); > +err: > + return ret; > +} > + > +static int __devexit i2c_mux_pinctrl_remove(struct platform_device *pdev) > +{ > + struct i2c_mux_pinctrl *mux = platform_get_drvdata(pdev); > + int i; > + > + for (i = 0; i < mux->pdata->bus_count; i++) > + i2c_del_mux_adapter(mux->busses[i]); > + > + i2c_put_adapter(mux->parent); > + > + return 0; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id i2c_mux_pinctrl_of_match[] __devinitconst = > { > + { .compatible = "i2c-mux-pinctrl", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match); > +#endif > + > +static struct platform_driver i2c_mux_pinctrl_driver = { > + .driver = { > + .name = "i2c-mux-pinctrl", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(i2c_mux_pinctrl_of_match), > + }, > + .probe = i2c_mux_pinctrl_probe, > + .remove = __devexit_p(i2c_mux_pinctrl_remove), > +}; > +module_platform_driver(i2c_mux_pinctrl_driver); > + > +MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver"); > +MODULE_AUTHOR("Stephen Warren <[email protected]>"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform:i2c-mux-pinctrl"); > diff --git a/include/linux/i2c-mux-pinctrl.h b/include/linux/i2c-mux-pinctrl.h > new file mode 100644 > index 0000000..a65c864 > --- /dev/null > +++ b/include/linux/i2c-mux-pinctrl.h > @@ -0,0 +1,41 @@ > +/* > + * i2c-mux-pinctrl platform data > + * > + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#ifndef _LINUX_I2C_MUX_PINCTRL_H > +#define _LINUX_I2C_MUX_PINCTRL_H > + > +/** > + * struct i2c_mux_pinctrl_platform_data - Platform data for i2c-mux-pinctrl > + * @parent_bus_num: Parent I2C bus number > + * @base_bus_num: Base I2C bus number for the child busses. 0 for dynamic. > + * @bus_count: Number of child busses. Also the number of elements in > + * @pinctrl_states > + * @pinctrl_states: The names of the pinctrl state to select for each child > bus > + * @pinctrl_state_idle: The pinctrl state to select when no child bus is > being > + * accessed. If NULL, the most recently used pinctrl state will be left > + * selected. > + */ > +struct i2c_mux_pinctrl_platform_data { > + int parent_bus_num; > + int base_bus_num; > + int bus_count; > + const char **pinctrl_states; > + const char *pinctrl_state_idle; > +}; > + > +#endif -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
