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![Linus Torvalds](/assets/img/avatar_default.png)
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 ...
243 lines
5.4 KiB
C
243 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* I2C multiplexer using GPIO API
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*
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* Peter Korsgaard <peter.korsgaard@barco.com>
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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/platform_data/i2c-mux-gpio.h>
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#include <linux/platform_device.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/bits.h>
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#include <linux/gpio/consumer.h>
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/* FIXME: stop poking around inside gpiolib */
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#include "../../gpio/gpiolib.h"
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struct gpiomux {
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struct i2c_mux_gpio_platform_data data;
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int ngpios;
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struct gpio_desc **gpios;
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};
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static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
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{
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DECLARE_BITMAP(values, BITS_PER_TYPE(val));
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values[0] = val;
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gpiod_set_array_value_cansleep(mux->ngpios, mux->gpios, NULL, values);
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}
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static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)
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{
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struct gpiomux *mux = i2c_mux_priv(muxc);
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i2c_mux_gpio_set(mux, chan);
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return 0;
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}
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static int i2c_mux_gpio_deselect(struct i2c_mux_core *muxc, u32 chan)
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{
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struct gpiomux *mux = i2c_mux_priv(muxc);
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i2c_mux_gpio_set(mux, mux->data.idle);
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return 0;
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}
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#ifdef CONFIG_OF
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static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
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struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct device_node *adapter_np, *child;
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struct i2c_adapter *adapter;
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unsigned *values;
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int i = 0;
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if (!np)
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return -ENODEV;
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adapter_np = of_parse_phandle(np, "i2c-parent", 0);
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if (!adapter_np) {
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dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
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return -ENODEV;
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}
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adapter = of_find_i2c_adapter_by_node(adapter_np);
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of_node_put(adapter_np);
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if (!adapter)
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return -EPROBE_DEFER;
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mux->data.parent = i2c_adapter_id(adapter);
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put_device(&adapter->dev);
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mux->data.n_values = of_get_child_count(np);
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values = devm_kcalloc(&pdev->dev,
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mux->data.n_values, sizeof(*mux->data.values),
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GFP_KERNEL);
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if (!values) {
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dev_err(&pdev->dev, "Cannot allocate values array");
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return -ENOMEM;
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}
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for_each_child_of_node(np, child) {
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of_property_read_u32(child, "reg", values + i);
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i++;
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}
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mux->data.values = values;
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if (of_property_read_u32(np, "idle-state", &mux->data.idle))
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mux->data.idle = I2C_MUX_GPIO_NO_IDLE;
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return 0;
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}
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#else
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static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
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struct platform_device *pdev)
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{
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return 0;
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}
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#endif
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static int i2c_mux_gpio_probe(struct platform_device *pdev)
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{
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struct i2c_mux_core *muxc;
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struct gpiomux *mux;
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struct i2c_adapter *parent;
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struct i2c_adapter *root;
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unsigned initial_state;
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int i, ngpios, ret;
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mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
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if (!mux)
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return -ENOMEM;
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if (!dev_get_platdata(&pdev->dev)) {
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ret = i2c_mux_gpio_probe_dt(mux, pdev);
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if (ret < 0)
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return ret;
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} else {
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memcpy(&mux->data, dev_get_platdata(&pdev->dev),
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sizeof(mux->data));
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}
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ngpios = gpiod_count(&pdev->dev, "mux");
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if (ngpios <= 0) {
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dev_err(&pdev->dev, "no valid gpios provided\n");
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return ngpios ?: -EINVAL;
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}
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mux->ngpios = ngpios;
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parent = i2c_get_adapter(mux->data.parent);
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if (!parent)
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return -EPROBE_DEFER;
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muxc = i2c_mux_alloc(parent, &pdev->dev, mux->data.n_values,
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ngpios * sizeof(*mux->gpios), 0,
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i2c_mux_gpio_select, NULL);
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if (!muxc) {
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ret = -ENOMEM;
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goto alloc_failed;
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}
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mux->gpios = muxc->priv;
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muxc->priv = mux;
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platform_set_drvdata(pdev, muxc);
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root = i2c_root_adapter(&parent->dev);
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muxc->mux_locked = true;
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if (mux->data.idle != I2C_MUX_GPIO_NO_IDLE) {
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initial_state = mux->data.idle;
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muxc->deselect = i2c_mux_gpio_deselect;
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} else {
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initial_state = mux->data.values[0];
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}
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for (i = 0; i < ngpios; i++) {
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struct device *gpio_dev;
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struct gpio_desc *gpiod;
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enum gpiod_flags flag;
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if (initial_state & BIT(i))
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flag = GPIOD_OUT_HIGH;
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else
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flag = GPIOD_OUT_LOW;
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gpiod = devm_gpiod_get_index(&pdev->dev, "mux", i, flag);
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if (IS_ERR(gpiod)) {
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ret = PTR_ERR(gpiod);
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goto alloc_failed;
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}
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mux->gpios[i] = gpiod;
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if (!muxc->mux_locked)
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continue;
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/* FIXME: find a proper way to access the GPIO device */
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gpio_dev = &gpiod->gdev->dev;
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muxc->mux_locked = i2c_root_adapter(gpio_dev) == root;
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}
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if (muxc->mux_locked)
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dev_info(&pdev->dev, "mux-locked i2c mux\n");
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for (i = 0; i < mux->data.n_values; i++) {
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u32 nr = mux->data.base_nr ? (mux->data.base_nr + i) : 0;
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unsigned int class = mux->data.classes ? mux->data.classes[i] : 0;
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ret = i2c_mux_add_adapter(muxc, nr, mux->data.values[i], class);
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if (ret)
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goto add_adapter_failed;
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}
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dev_info(&pdev->dev, "%d port mux on %s adapter\n",
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mux->data.n_values, parent->name);
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return 0;
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add_adapter_failed:
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i2c_mux_del_adapters(muxc);
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alloc_failed:
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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_gpio_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_gpio_of_match[] = {
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{ .compatible = "i2c-mux-gpio", },
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{},
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};
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MODULE_DEVICE_TABLE(of, i2c_mux_gpio_of_match);
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static struct platform_driver i2c_mux_gpio_driver = {
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.probe = i2c_mux_gpio_probe,
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.remove = i2c_mux_gpio_remove,
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.driver = {
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.name = "i2c-mux-gpio",
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.of_match_table = i2c_mux_gpio_of_match,
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},
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};
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module_platform_driver(i2c_mux_gpio_driver);
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MODULE_DESCRIPTION("GPIO-based I2C multiplexer driver");
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MODULE_AUTHOR("Peter Korsgaard <peter.korsgaard@barco.com>");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:i2c-mux-gpio");
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