Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * I2C multiplexer using pinctrl API
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/i2c-mux.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/pinctrl/consumer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/platform_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/of.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include "../../pinctrl/core.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) struct i2c_mux_pinctrl {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 	struct pinctrl *pinctrl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 	struct pinctrl_state *states[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	struct i2c_mux_pinctrl *mux = i2c_mux_priv(muxc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) static int i2c_mux_pinctrl_deselect(struct i2c_mux_core *muxc, u32 chan)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	return i2c_mux_pinctrl_select(muxc, muxc->num_adapters);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) static struct i2c_adapter *i2c_mux_pinctrl_root_adapter(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	struct pinctrl_state *state)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	struct i2c_adapter *root = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	struct pinctrl_setting *setting;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	struct i2c_adapter *pin_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	list_for_each_entry(setting, &state->settings, node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 		pin_root = i2c_root_adapter(setting->pctldev->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 		if (!pin_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 			return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 		if (!root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 			root = pin_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		else if (root != pin_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 			return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	return root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) static struct i2c_adapter *i2c_mux_pinctrl_parent_adapter(struct device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	struct device_node *np = dev->of_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	struct device_node *parent_np;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	struct i2c_adapter *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	parent_np = of_parse_phandle(np, "i2c-parent", 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	if (!parent_np) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 		dev_err(dev, "Cannot parse i2c-parent\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 		return ERR_PTR(-ENODEV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	parent = of_find_i2c_adapter_by_node(parent_np);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	of_node_put(parent_np);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	if (!parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 		return ERR_PTR(-EPROBE_DEFER);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	return parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	struct device *dev = &pdev->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	struct device_node *np = dev->of_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	struct i2c_mux_core *muxc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	struct i2c_mux_pinctrl *mux;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	struct i2c_adapter *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	struct i2c_adapter *root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	int num_names, i, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	num_names = of_property_count_strings(np, "pinctrl-names");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	if (num_names < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		dev_err(dev, "Cannot parse pinctrl-names: %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 			num_names);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		return num_names;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	parent = i2c_mux_pinctrl_parent_adapter(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	if (IS_ERR(parent))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		return PTR_ERR(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	muxc = i2c_mux_alloc(parent, dev, num_names,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 			     struct_size(mux, states, num_names),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			     0, i2c_mux_pinctrl_select, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	if (!muxc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		goto err_put_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	mux = i2c_mux_priv(muxc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	platform_set_drvdata(pdev, muxc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	mux->pinctrl = devm_pinctrl_get(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	if (IS_ERR(mux->pinctrl)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		ret = PTR_ERR(mux->pinctrl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		dev_err(dev, "Cannot get pinctrl: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		goto err_put_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	for (i = 0; i < num_names; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 		ret = of_property_read_string_index(np, "pinctrl-names", i,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 						    &name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 		if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 			dev_err(dev, "Cannot parse pinctrl-names: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 			goto err_put_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		mux->states[i] = pinctrl_lookup_state(mux->pinctrl, name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 		if (IS_ERR(mux->states[i])) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 			ret = PTR_ERR(mux->states[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 			dev_err(dev, "Cannot look up pinctrl state %s: %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 				name, ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 			goto err_put_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		if (strcmp(name, "idle"))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		if (i != num_names - 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 			dev_err(dev, "idle state must be last\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 			ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 			goto err_put_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		muxc->deselect = i2c_mux_pinctrl_deselect;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	root = i2c_root_adapter(&muxc->parent->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	muxc->mux_locked = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	for (i = 0; i < num_names; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		if (root != i2c_mux_pinctrl_root_adapter(mux->states[i])) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			muxc->mux_locked = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	if (muxc->mux_locked)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 		dev_info(dev, "mux-locked i2c mux\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	/* Do not add any adapter for the idle state (if it's there at all). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	for (i = 0; i < num_names - !!muxc->deselect; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 		ret = i2c_mux_add_adapter(muxc, 0, i, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 		if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 			goto err_del_adapter;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) err_del_adapter:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	i2c_mux_del_adapters(muxc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) err_put_parent:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	i2c_put_adapter(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) static int i2c_mux_pinctrl_remove(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	i2c_mux_del_adapters(muxc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	i2c_put_adapter(muxc->parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) static const struct of_device_id i2c_mux_pinctrl_of_match[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	{ .compatible = "i2c-mux-pinctrl", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	{},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) static struct platform_driver i2c_mux_pinctrl_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	.driver	= {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		.name	= "i2c-mux-pinctrl",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		.of_match_table = of_match_ptr(i2c_mux_pinctrl_of_match),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	.probe	= i2c_mux_pinctrl_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	.remove	= i2c_mux_pinctrl_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) module_platform_driver(i2c_mux_pinctrl_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) MODULE_LICENSE("GPL v2");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) MODULE_ALIAS("platform:i2c-mux-pinctrl");