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Pull i2c updates from Wolfram Sang: "New stuff from the I2C world: - in the core, getting irqs from ACPI is now similar to OF - new driver for MediaTek MT7621/7628/7688 SoCs - bcm2835, i801, and tegra drivers got some more attention - GPIO API cleanups - cleanups in the core headers - lots of usual driver updates" * 'i2c/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (74 commits) i2c: mt7621: Fix platform_no_drv_owner.cocci warnings i2c: cpm: remove casting dma_alloc dt-bindings: i2c: sun6i-p2wi: Fix the binding example dt-bindings: i2c: mv64xxx: Fix the example compatible i2c: i801: Documentation update i2c: i801: Add support for Intel Tiger Lake i2c: i801: Fix PCI ID sorting dt-bindings: i2c-stm32: document optional dmas i2c: i2c-stm32f7: Add I2C_SMBUS_I2C_BLOCK_DATA support i2c: core: Tidy up handling of init_irq i2c: core: Move ACPI gpio IRQ handling into i2c_acpi_get_irq i2c: core: Move ACPI IRQ handling to probe time i2c: acpi: Factor out getting the IRQ from ACPI i2c: acpi: Use available IRQ helper functions i2c: core: Allow whole core to use i2c_dev_irq_from_resources eeprom: at24: modify a comment referring to platform data dt-bindings: i2c: omap: Add new compatible for J721E SoCs dt-bindings: i2c: mv64xxx: Add YAML schemas dt-bindings: i2c: sun6i-p2wi: Add YAML schemas i2c: mt7621: Add MediaTek MT7621/7628/7688 I2C driver ...
198 lines
4.7 KiB
C
198 lines
4.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* I2C multiplexer using pinctrl API
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*
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* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
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*/
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#include <linux/i2c.h>
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#include <linux/i2c-mux.h>
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#include <linux/module.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include "../../pinctrl/core.h"
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struct i2c_mux_pinctrl {
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struct pinctrl *pinctrl;
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struct pinctrl_state *states[];
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};
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static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan)
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{
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struct i2c_mux_pinctrl *mux = i2c_mux_priv(muxc);
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return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
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}
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static int i2c_mux_pinctrl_deselect(struct i2c_mux_core *muxc, u32 chan)
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{
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return i2c_mux_pinctrl_select(muxc, muxc->num_adapters);
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}
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static struct i2c_adapter *i2c_mux_pinctrl_root_adapter(
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struct pinctrl_state *state)
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{
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struct i2c_adapter *root = NULL;
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struct pinctrl_setting *setting;
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struct i2c_adapter *pin_root;
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list_for_each_entry(setting, &state->settings, node) {
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pin_root = i2c_root_adapter(setting->pctldev->dev);
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if (!pin_root)
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return NULL;
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if (!root)
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root = pin_root;
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else if (root != pin_root)
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return NULL;
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}
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return root;
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}
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static struct i2c_adapter *i2c_mux_pinctrl_parent_adapter(struct device *dev)
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{
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struct device_node *np = dev->of_node;
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struct device_node *parent_np;
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struct i2c_adapter *parent;
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parent_np = of_parse_phandle(np, "i2c-parent", 0);
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if (!parent_np) {
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dev_err(dev, "Cannot parse i2c-parent\n");
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return ERR_PTR(-ENODEV);
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}
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parent = of_find_i2c_adapter_by_node(parent_np);
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of_node_put(parent_np);
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if (!parent)
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return ERR_PTR(-EPROBE_DEFER);
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return parent;
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}
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static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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struct i2c_mux_core *muxc;
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struct i2c_mux_pinctrl *mux;
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struct i2c_adapter *parent;
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struct i2c_adapter *root;
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int num_names, i, ret;
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const char *name;
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num_names = of_property_count_strings(np, "pinctrl-names");
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if (num_names < 0) {
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dev_err(dev, "Cannot parse pinctrl-names: %d\n",
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num_names);
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return num_names;
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}
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parent = i2c_mux_pinctrl_parent_adapter(dev);
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if (IS_ERR(parent))
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return PTR_ERR(parent);
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muxc = i2c_mux_alloc(parent, dev, num_names,
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struct_size(mux, states, num_names),
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0, i2c_mux_pinctrl_select, NULL);
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if (!muxc) {
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ret = -ENOMEM;
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goto err_put_parent;
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}
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mux = i2c_mux_priv(muxc);
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platform_set_drvdata(pdev, muxc);
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mux->pinctrl = devm_pinctrl_get(dev);
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if (IS_ERR(mux->pinctrl)) {
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ret = PTR_ERR(mux->pinctrl);
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dev_err(dev, "Cannot get pinctrl: %d\n", ret);
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goto err_put_parent;
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}
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for (i = 0; i < num_names; i++) {
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ret = of_property_read_string_index(np, "pinctrl-names", i,
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&name);
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if (ret < 0) {
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dev_err(dev, "Cannot parse pinctrl-names: %d\n", ret);
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goto err_put_parent;
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}
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mux->states[i] = pinctrl_lookup_state(mux->pinctrl, name);
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if (IS_ERR(mux->states[i])) {
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ret = PTR_ERR(mux->states[i]);
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dev_err(dev, "Cannot look up pinctrl state %s: %d\n",
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name, ret);
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goto err_put_parent;
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}
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if (strcmp(name, "idle"))
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continue;
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if (i != num_names - 1) {
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dev_err(dev, "idle state must be last\n");
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ret = -EINVAL;
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goto err_put_parent;
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}
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muxc->deselect = i2c_mux_pinctrl_deselect;
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}
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root = i2c_root_adapter(&muxc->parent->dev);
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muxc->mux_locked = true;
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for (i = 0; i < num_names; i++) {
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if (root != i2c_mux_pinctrl_root_adapter(mux->states[i])) {
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muxc->mux_locked = false;
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break;
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}
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}
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if (muxc->mux_locked)
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dev_info(dev, "mux-locked i2c mux\n");
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/* Do not add any adapter for the idle state (if it's there at all). */
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for (i = 0; i < num_names - !!muxc->deselect; i++) {
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ret = i2c_mux_add_adapter(muxc, 0, i, 0);
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if (ret)
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goto err_del_adapter;
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}
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return 0;
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err_del_adapter:
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i2c_mux_del_adapters(muxc);
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err_put_parent:
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i2c_put_adapter(parent);
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return ret;
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}
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static int i2c_mux_pinctrl_remove(struct platform_device *pdev)
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{
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struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
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i2c_mux_del_adapters(muxc);
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i2c_put_adapter(muxc->parent);
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return 0;
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}
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static const struct of_device_id i2c_mux_pinctrl_of_match[] = {
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{ .compatible = "i2c-mux-pinctrl", },
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{},
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};
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MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match);
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static struct platform_driver i2c_mux_pinctrl_driver = {
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.driver = {
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.name = "i2c-mux-pinctrl",
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.of_match_table = of_match_ptr(i2c_mux_pinctrl_of_match),
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},
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.probe = i2c_mux_pinctrl_probe,
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.remove = i2c_mux_pinctrl_remove,
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};
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module_platform_driver(i2c_mux_pinctrl_driver);
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MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
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MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:i2c-mux-pinctrl");
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