diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-05 17:55:31 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-05 17:55:31 (GMT) |
commit | 690efa08e268a36df170bee79df93a9649c3f217 (patch) | |
tree | 16fa1ccd5cefd3db92201908ca2a1051f86799db /drivers | |
parent | 5698e9180cb70020bbf8b613174afe6308f902b0 (diff) | |
parent | ae58d1e406986f31d1e88b32f5ac601506c196d8 (diff) | |
download | linux-fsl-qoriq-690efa08e268a36df170bee79df93a9649c3f217.tar.xz |
Merge branch 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux
Pull embedded i2c update from Wolfram Sang:
"This only contains one new driver which had multiple dependencies
(pinctrl, i2c-mux-rework, new devm_* functions), so I decided to wait
for rc1. Plus, it had to wait a little for the ack of a devicetree
maintainer since the bindings were not trivial enough for me to pass
through.
So, given that, I hope there is still something like the "new driver
rule", so we could have the driver in 3.5 and people can start using
it. That would make merging support for some boards easier for 3.6
since the dependency on this driver is gone then."
* 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux:
i2c: Add generic I2C multiplexer using pinctrl API
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/i2c/muxes/Kconfig | 12 | ||||
-rw-r--r-- | drivers/i2c/muxes/Makefile | 1 | ||||
-rw-r--r-- | drivers/i2c/muxes/i2c-mux-pinctrl.c | 279 |
3 files changed, 292 insertions, 0 deletions
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig index beb2491..a0edd98 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 5826249..76da869 100644 --- a/drivers/i2c/muxes/Makefile +++ b/drivers/i2c/muxes/Makefile @@ -4,5 +4,6 @@ obj-$(CONFIG_I2C_MUX_GPIO) += i2c-mux-gpio.o obj-$(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 <swarren@nvidia.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:i2c-mux-pinctrl"); |