mux: adg792a: add mux controller driver for ADG792A/G

Analog Devices ADG792A/G is a triple 4:1 mux.

Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
index 738670aaecb7243c9c73fde1677ba90eb664276d..c4d050645605ec0a232fa0a8b50c415eeec47045 100644 (file)
--- a/drivers/mux/Kconfig
+++ b/drivers/mux/Kconfig
@@ -17,6 +17,18 @@ menuconfig MULTIPLEXER
 
 if MULTIPLEXER
 
+config MUX_ADG792A
+       tristate "Analog Devices ADG792A/ADG792G Multiplexers"
+       depends on I2C || COMPILE_TEST
+       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 GPIOLIB || COMPILE_TEST

diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
index bb16953f6290fb782bf90992ea7fa12968cfe4f3..b00a7d37d2fbe797b9c3d1a3da8a110d8f3afc54 100644 (file)
--- 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 (file)
index 0000000..12aa221
--- /dev/null
+++ b/drivers/mux/mux-adg792a.c
@@ -0,0 +1,157 @@
+/*
+ * Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux
+ *
+ * Copyright (C) 2017 Axentia Technologies AB
+ *
+ * Author: Peter Rosin <peda@axentia.se>
+ *
+ * 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/driver.h>
+#include <linux/property.h>
+
+#define ADG792A_LDSW           BIT(0)
+#define ADG792A_RESETB         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))
+
+static int adg792a_write_cmd(struct i2c_client *i2c, u8 cmd, int reset)
+{
+       u8 data = ADG792A_RESETB | ADG792A_LDSW;
+
+       /* ADG792A_RESETB is active low, the chip resets when it is zero. */
+       if (reset)
+               data &= ~ADG792A_RESETB;
+
+       return i2c_smbus_write_byte_data(i2c, cmd, data);
+}
+
+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 == MUX_IDLE_DISCONNECT)
+                       cmd = ADG792A_DISABLE_ALL;
+               else
+                       cmd = ADG792A_MUX_ALL(state);
+       } else {
+               unsigned int controller = mux_control_get_index(mux);
+
+               if (state == MUX_IDLE_DISCONNECT)
+                       cmd = ADG792A_DISABLE(controller);
+               else
+                       cmd = ADG792A_MUX(controller, state);
+       }
+
+       return adg792a_write_cmd(i2c, cmd, 0);
+}
+
+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;
+       s32 idle_state[3];
+       u32 cells;
+       int ret;
+       int i;
+
+       if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+               return -ENODEV;
+
+       ret = device_property_read_u32(dev, "#mux-control-cells", &cells);
+       if (ret < 0)
+               return ret;
+       if (cells >= 2)
+               return -EINVAL;
+
+       mux_chip = devm_mux_chip_alloc(dev, cells ? 3 : 1, 0);
+       if (IS_ERR(mux_chip))
+               return PTR_ERR(mux_chip);
+
+       mux_chip->ops = &adg792a_ops;
+
+       ret = adg792a_write_cmd(i2c, ADG792A_DISABLE_ALL, 1);
+       if (ret < 0)
+               return ret;
+
+       ret = device_property_read_u32_array(dev, "idle-state",
+                                            (u32 *)idle_state,
+                                            mux_chip->controllers);
+       if (ret < 0) {
+               idle_state[0] = MUX_IDLE_AS_IS;
+               idle_state[1] = MUX_IDLE_AS_IS;
+               idle_state[2] = MUX_IDLE_AS_IS;
+       }
+
+       for (i = 0; i < mux_chip->controllers; ++i) {
+               struct mux_control *mux = &mux_chip->mux[i];
+
+               mux->states = 4;
+
+               switch (idle_state[i]) {
+               case MUX_IDLE_DISCONNECT:
+               case MUX_IDLE_AS_IS:
+               case 0 ... 4:
+                       mux->idle_state = idle_state[i];
+                       break;
+               default:
+                       dev_err(dev, "invalid idle-state %d\n", idle_state[i]);
+                       return -EINVAL;
+               }
+       }
+
+       ret = devm_mux_chip_register(dev, mux_chip);
+       if (ret < 0)
+               return ret;
+
+       if (cells)
+               dev_info(dev, "3x single pole quadruple throw muxes registered\n");
+       else
+               dev_info(dev, "triple pole quadruple throw mux 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@axentia.se>");
+MODULE_LICENSE("GPL v2");