On 04/01/17 12:16, Peter Rosin wrote: > Analog Devices ADG792A/G is a triple 4:1 mux. > > Signed-off-by: Peter Rosin <peda@xxxxxxxxxx> Reviewed-by: Jonathan Cameron <jic23@xxxxxxxxxx> A nice little driver. Hopefully this example will do the job of convincing people a subsystem makes sense! Jonathan > --- > drivers/mux/Kconfig | 12 ++++ > drivers/mux/Makefile | 1 + > drivers/mux/mux-adg792a.c | 169 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 182 insertions(+) > create mode 100644 drivers/mux/mux-adg792a.c > > diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig > index de5a35ffe7af..39b06e19aa96 100644 > --- a/drivers/mux/Kconfig > +++ b/drivers/mux/Kconfig > @@ -16,6 +16,18 @@ menuconfig MULTIPLEXER > > if MULTIPLEXER > > +config MUX_ADG792A > + tristate "Analog Devices ADG792A/ADG792G Multiplexers" > + depends on I2C > + help > + ADG792A and ADG792G Wide Bandwidth Triple 4:1 Multiplexers > + > + The driver supports both operating the three multiplexers in > + parallel and operating them independently. > + > + To compile the driver as a module, choose M here: the module will > + be called mux-adg792a. > + > config MUX_GPIO > tristate "GPIO-controlled Multiplexer" > depends on OF && GPIOLIB > diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile > index facc43da3648..fddbb073fc77 100644 > --- a/drivers/mux/Makefile > +++ b/drivers/mux/Makefile > @@ -3,4 +3,5 @@ > # > > obj-$(CONFIG_MULTIPLEXER) += mux-core.o > +obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o > obj-$(CONFIG_MUX_GPIO) += mux-gpio.o > diff --git a/drivers/mux/mux-adg792a.c b/drivers/mux/mux-adg792a.c > new file mode 100644 > index 000000000000..c6d5c4571e7c > --- /dev/null > +++ b/drivers/mux/mux-adg792a.c > @@ -0,0 +1,169 @@ > +/* > + * Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux > + * > + * Copyright (C) 2016 Axentia Technologies AB > + * > + * Author: Peter Rosin <peda@xxxxxxxxxx> > + * > + * 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 <linux/err.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/mux.h> > + > +#define ADG792A_LDSW BIT(0) > +#define ADG792A_RESET BIT(1) > +#define ADG792A_DISABLE(mux) (0x50 | (mux)) > +#define ADG792A_DISABLE_ALL (0x5f) > +#define ADG792A_MUX(mux, state) (0xc0 | (((mux) + 1) << 2) | (state)) > +#define ADG792A_MUX_ALL(state) (0xc0 | (state)) > + > +#define ADG792A_DISABLE_STATE (4) > + > +static int adg792a_set(struct mux_control *mux, int state) > +{ > + struct i2c_client *i2c = to_i2c_client(mux->chip->dev.parent); > + u8 cmd; > + > + if (mux->chip->controllers == 1) { > + /* parallel mux controller operation */ > + if (state == ADG792A_DISABLE_STATE) > + cmd = ADG792A_DISABLE_ALL; > + else > + cmd = ADG792A_MUX_ALL(state); > + } else { > + unsigned int controller = mux_control_get_index(mux); > + > + if (state == ADG792A_DISABLE_STATE) > + cmd = ADG792A_DISABLE(controller); > + else > + cmd = ADG792A_MUX(controller, state); > + } > + > + return i2c_smbus_write_byte_data(i2c, cmd, ADG792A_LDSW); > +} > + > +static const struct mux_control_ops adg792a_ops = { > + .set = adg792a_set, > +}; > + > +static int adg792a_probe(struct i2c_client *i2c, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &i2c->dev; > + struct mux_chip *mux_chip; > + bool parallel; > + int count; > + int ret; > + int i; > + > + parallel = of_property_read_bool(i2c->dev.of_node, "adi,parallel"); > + > + mux_chip = devm_mux_chip_alloc(dev, parallel ? 1 : 3, 0); > + if (!mux_chip) > + return -ENOMEM; > + > + mux_chip->ops = &adg792a_ops; > + > + ret = i2c_smbus_write_byte_data(i2c, ADG792A_DISABLE_ALL, > + ADG792A_RESET | ADG792A_LDSW); > + if (ret < 0) > + return ret; > + > + for (i = 0; i < mux_chip->controllers; ++i) { > + struct mux_control *mux = &mux_chip->mux[i]; > + > + mux->states = 4; > + } > + > + count = of_property_count_u32_elems(dev->of_node, "adi,idle-state"); > + for (i = 0; i < count; i += 2) { > + u32 index; > + u32 idle_state; > + > + ret = of_property_read_u32_index(dev->of_node, > + "adi,idle-state", i, > + &index); > + if (ret < 0) > + return ret; > + if (index >= mux_chip->controllers) { > + dev_err(dev, "invalid mux %u\n", index); > + return -EINVAL; > + } > + > + ret = of_property_read_u32_index(dev->of_node, > + "adi,idle-state", i + 1, > + &idle_state); > + if (ret < 0) > + return ret; > + if (idle_state >= ADG792A_DISABLE_STATE) { > + dev_err(dev, "invalid idle-state %u for mux %u\n", > + idle_state, index); > + return -EINVAL; > + } > + mux_chip->mux[index].idle_state = idle_state; > + } > + > + count = of_property_count_u32_elems(dev->of_node, > + "adi,idle-high-impedance"); > + for (i = 0; i < count; ++i) { > + u32 index; > + > + ret = of_property_read_u32_index(dev->of_node, > + "adi,idle-high-impedance", i, > + &index); > + if (ret < 0) > + return ret; > + if (index >= mux_chip->controllers) { > + dev_err(dev, "invalid mux %u\n", index); > + return -EINVAL; > + } > + > + mux_chip->mux[index].idle_state = ADG792A_DISABLE_STATE; > + } > + > + ret = devm_mux_chip_register(dev, mux_chip); > + if (ret < 0) { > + dev_err(dev, "failed to register mux-chip\n"); > + return ret; > + } > + > + if (parallel) > + dev_info(dev, "triple pole quadruple throw mux registered\n"); > + else > + dev_info(dev, "3x single pole quadruple throw muxes registered\n"); > + > + return 0; > +} > + > +static const struct i2c_device_id adg792a_id[] = { > + { .name = "adg792a", }, > + { .name = "adg792g", }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, adg792a_id); > + > +static const struct of_device_id adg792a_of_match[] = { > + { .compatible = "adi,adg792a", }, > + { .compatible = "adi,adg792g", }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, adg792a_of_match); > + > +static struct i2c_driver adg792a_driver = { > + .driver = { > + .name = "adg792a", > + .of_match_table = of_match_ptr(adg792a_of_match), > + }, > + .probe = adg792a_probe, > + .id_table = adg792a_id, > +}; > +module_i2c_driver(adg792a_driver); > + > +MODULE_DESCRIPTION("Analog Devices ADG792A/G Triple 4:1 mux driver"); > +MODULE_AUTHOR("Peter Rosin <peda@xxxxxxxxxx"); > +MODULE_LICENSE("GPL v2"); > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html