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path: root/drivers/mux/mux-adg792a.c
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Diffstat (limited to 'drivers/mux/mux-adg792a.c')
-rw-r--r--drivers/mux/mux-adg792a.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/drivers/mux/mux-adg792a.c b/drivers/mux/mux-adg792a.c
new file mode 100644
index 000000000000..12aa221ab90d
--- /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");