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153 lines
3.6 KiB
153 lines
3.6 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Multiplexer driver for Analog Devices ADG792A/G Triple 4:1 mux |
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* |
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* Copyright (C) 2017 Axentia Technologies AB |
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* |
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* Author: Peter Rosin <[email protected]> |
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*/ |
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#include <linux/err.h> |
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#include <linux/i2c.h> |
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#include <linux/module.h> |
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#include <linux/mux/driver.h> |
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#include <linux/property.h> |
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#define ADG792A_LDSW BIT(0) |
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#define ADG792A_RESETB BIT(1) |
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#define ADG792A_DISABLE(mux) (0x50 | (mux)) |
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#define ADG792A_DISABLE_ALL (0x5f) |
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#define ADG792A_MUX(mux, state) (0xc0 | (((mux) + 1) << 2) | (state)) |
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#define ADG792A_MUX_ALL(state) (0xc0 | (state)) |
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static int adg792a_write_cmd(struct i2c_client *i2c, u8 cmd, int reset) |
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{ |
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u8 data = ADG792A_RESETB | ADG792A_LDSW; |
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/* ADG792A_RESETB is active low, the chip resets when it is zero. */ |
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if (reset) |
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data &= ~ADG792A_RESETB; |
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return i2c_smbus_write_byte_data(i2c, cmd, data); |
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} |
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static int adg792a_set(struct mux_control *mux, int state) |
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{ |
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struct i2c_client *i2c = to_i2c_client(mux->chip->dev.parent); |
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u8 cmd; |
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if (mux->chip->controllers == 1) { |
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/* parallel mux controller operation */ |
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if (state == MUX_IDLE_DISCONNECT) |
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cmd = ADG792A_DISABLE_ALL; |
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else |
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cmd = ADG792A_MUX_ALL(state); |
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} else { |
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unsigned int controller = mux_control_get_index(mux); |
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if (state == MUX_IDLE_DISCONNECT) |
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cmd = ADG792A_DISABLE(controller); |
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else |
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cmd = ADG792A_MUX(controller, state); |
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} |
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return adg792a_write_cmd(i2c, cmd, 0); |
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} |
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static const struct mux_control_ops adg792a_ops = { |
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.set = adg792a_set, |
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}; |
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static int adg792a_probe(struct i2c_client *i2c) |
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{ |
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struct device *dev = &i2c->dev; |
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struct mux_chip *mux_chip; |
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s32 idle_state[3]; |
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u32 cells; |
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int ret; |
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int i; |
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if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
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return -ENODEV; |
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ret = device_property_read_u32(dev, "#mux-control-cells", &cells); |
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if (ret < 0) |
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return ret; |
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if (cells >= 2) |
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return -EINVAL; |
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mux_chip = devm_mux_chip_alloc(dev, cells ? 3 : 1, 0); |
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if (IS_ERR(mux_chip)) |
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return PTR_ERR(mux_chip); |
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mux_chip->ops = &adg792a_ops; |
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ret = adg792a_write_cmd(i2c, ADG792A_DISABLE_ALL, 1); |
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if (ret < 0) |
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return ret; |
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ret = device_property_read_u32_array(dev, "idle-state", |
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(u32 *)idle_state, |
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mux_chip->controllers); |
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if (ret < 0) { |
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idle_state[0] = MUX_IDLE_AS_IS; |
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idle_state[1] = MUX_IDLE_AS_IS; |
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idle_state[2] = MUX_IDLE_AS_IS; |
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} |
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for (i = 0; i < mux_chip->controllers; ++i) { |
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struct mux_control *mux = &mux_chip->mux[i]; |
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mux->states = 4; |
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switch (idle_state[i]) { |
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case MUX_IDLE_DISCONNECT: |
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case MUX_IDLE_AS_IS: |
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case 0 ... 4: |
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mux->idle_state = idle_state[i]; |
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break; |
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default: |
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dev_err(dev, "invalid idle-state %d\n", idle_state[i]); |
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return -EINVAL; |
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} |
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} |
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ret = devm_mux_chip_register(dev, mux_chip); |
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if (ret < 0) |
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return ret; |
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if (cells) |
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dev_info(dev, "3x single pole quadruple throw muxes registered\n"); |
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else |
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dev_info(dev, "triple pole quadruple throw mux registered\n"); |
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return 0; |
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} |
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static const struct i2c_device_id adg792a_id[] = { |
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{ .name = "adg792a", }, |
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{ .name = "adg792g", }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, adg792a_id); |
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static const struct of_device_id adg792a_of_match[] = { |
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{ .compatible = "adi,adg792a", }, |
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{ .compatible = "adi,adg792g", }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, adg792a_of_match); |
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static struct i2c_driver adg792a_driver = { |
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.driver = { |
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.name = "adg792a", |
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.of_match_table = of_match_ptr(adg792a_of_match), |
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}, |
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.probe_new = adg792a_probe, |
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.id_table = adg792a_id, |
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}; |
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module_i2c_driver(adg792a_driver); |
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MODULE_DESCRIPTION("Analog Devices ADG792A/G Triple 4:1 mux driver"); |
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MODULE_AUTHOR("Peter Rosin <[email protected]>"); |
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MODULE_LICENSE("GPL v2");
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