diff options
| -rw-r--r-- | MAINTAINERS | 8 | ||||
| -rw-r--r-- | arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi | 14 | ||||
| -rw-r--r-- | arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 4 | ||||
| -rw-r--r-- | drivers/i2c/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core-of-prober.c | 415 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core-smbus.c | 2 | ||||
| -rw-r--r-- | drivers/of/base.c | 36 | ||||
| -rw-r--r-- | drivers/of/dynamic.c | 44 | ||||
| -rw-r--r-- | drivers/platform/chrome/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/platform/chrome/Makefile | 1 | ||||
| -rw-r--r-- | drivers/platform/chrome/chromeos_of_hw_prober.c | 154 | ||||
| -rw-r--r-- | include/linux/i2c-of-prober.h | 140 | ||||
| -rw-r--r-- | include/linux/of.h | 13 |
13 files changed, 840 insertions, 3 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 7292e4a1ddb8..1e930c7a58b1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10758,6 +10758,14 @@ S: Maintained F: Documentation/devicetree/bindings/i2c/marvell,mv64xxx-i2c.yaml F: drivers/i2c/busses/i2c-mv64xxx.c +I2C OF COMPONENT PROBER +M: Chen-Yu Tsai <wenst@chromium.org> +L: linux-i2c@vger.kernel.org +L: devicetree@vger.kernel.org +S: Maintained +F: drivers/i2c/i2c-core-of-prober.c +F: include/linux/i2c-of-prober.h + I2C OVER PARALLEL PORT M: Jean Delvare <jdelvare@suse.com> L: linux-i2c@vger.kernel.org diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi index ae0379fd42a9..dfc5c2f0ddef 100644 --- a/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt8173-elm-hana.dtsi @@ -14,6 +14,7 @@ compatible = "melfas,mip4_ts"; reg = <0x34>; interrupts-extended = <&pio 88 IRQ_TYPE_LEVEL_LOW>; + status = "fail-needs-probe"; }; /* @@ -26,6 +27,7 @@ reg = <0x20>; hid-descr-addr = <0x0020>; interrupts-extended = <&pio 88 IRQ_TYPE_LEVEL_LOW>; + status = "fail-needs-probe"; }; /* Lenovo Ideapad C330 uses G2Touch touchscreen as a 2nd source touchscreen */ @@ -35,6 +37,7 @@ hid-descr-addr = <0x0001>; interrupt-parent = <&pio>; interrupts = <88 IRQ_TYPE_LEVEL_LOW>; + status = "fail-needs-probe"; }; }; @@ -47,6 +50,8 @@ trackpad2: trackpad@2c { compatible = "hid-over-i2c"; interrupts-extended = <&pio 117 IRQ_TYPE_LEVEL_LOW>; + pinctrl-names = "default"; + pinctrl-0 = <&trackpad_irq>; reg = <0x2c>; hid-descr-addr = <0x0020>; /* @@ -58,6 +63,7 @@ */ vdd-supply = <&mt6397_vgp6_reg>; wakeup-source; + status = "fail-needs-probe"; }; }; @@ -82,3 +88,11 @@ }; }; }; + +&touchscreen { + status = "fail-needs-probe"; +}; + +&trackpad { + status = "fail-needs-probe"; +}; diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi index b4d85147b77b..eee64461421f 100644 --- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi @@ -358,12 +358,12 @@ &i2c4 { clock-frequency = <400000>; status = "okay"; - pinctrl-names = "default"; - pinctrl-0 = <&trackpad_irq>; trackpad: trackpad@15 { compatible = "elan,ekth3000"; interrupts-extended = <&pio 117 IRQ_TYPE_LEVEL_LOW>; + pinctrl-names = "default"; + pinctrl-0 = <&trackpad_irq>; reg = <0x15>; vcc-supply = <&mt6397_vgp6_reg>; wakeup-source; diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index af95d6e7f004..d27de18de46f 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -9,6 +9,7 @@ i2c-core-y := i2c-core-base.o i2c-core-smbus.o i2c-core-$(CONFIG_ACPI) += i2c-core-acpi.o i2c-core-$(CONFIG_I2C_SLAVE) += i2c-core-slave.o i2c-core-$(CONFIG_OF) += i2c-core-of.o +i2c-core-$(CONFIG_OF_DYNAMIC) += i2c-core-of-prober.o obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o diff --git a/drivers/i2c/i2c-core-of-prober.c b/drivers/i2c/i2c-core-of-prober.c new file mode 100644 index 000000000000..b9ca785f8b17 --- /dev/null +++ b/drivers/i2c/i2c-core-of-prober.c @@ -0,0 +1,415 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Linux I2C core OF component prober code + * + * Copyright (C) 2024 Google LLC + */ + +#include <linux/cleanup.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/dev_printk.h> +#include <linux/err.h> +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/i2c-of-prober.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> +#include <linux/stddef.h> + +/* + * Some devices, such as Google Hana Chromebooks, are produced by multiple + * vendors each using their preferred components. Such components are all + * in the device tree. Instead of having all of them enabled and having each + * driver separately try and probe its device while fighting over shared + * resources, they can be marked as "fail-needs-probe" and have a prober + * figure out which one is actually used beforehand. + * + * This prober assumes such drop-in parts are on the same I2C bus, have + * non-conflicting addresses, and can be directly probed by seeing which + * address responds. + * + * TODO: + * - Support I2C muxes + */ + +static struct device_node *i2c_of_probe_get_i2c_node(struct device *dev, const char *type) +{ + struct device_node *node __free(device_node) = of_find_node_by_name(NULL, type); + if (!node) { + dev_err(dev, "Could not find %s device node\n", type); + return NULL; + } + + struct device_node *i2c_node __free(device_node) = of_get_parent(node); + if (!of_node_name_eq(i2c_node, "i2c")) { + dev_err(dev, "%s device isn't on I2C bus\n", type); + return NULL; + } + + if (!of_device_is_available(i2c_node)) { + dev_err(dev, "I2C controller not available\n"); + return NULL; + } + + return no_free_ptr(i2c_node); +} + +static int i2c_of_probe_enable_node(struct device *dev, struct device_node *node) +{ + int ret; + + dev_dbg(dev, "Enabling %pOF\n", node); + + struct of_changeset *ocs __free(kfree) = kzalloc(sizeof(*ocs), GFP_KERNEL); + if (!ocs) + return -ENOMEM; + + of_changeset_init(ocs); + ret = of_changeset_update_prop_string(ocs, node, "status", "okay"); + if (ret) + return ret; + + ret = of_changeset_apply(ocs); + if (ret) { + /* ocs needs to be explicitly cleaned up before being freed. */ + of_changeset_destroy(ocs); + } else { + /* + * ocs is intentionally kept around as it needs to + * exist as long as the change is applied. + */ + void *ptr __always_unused = no_free_ptr(ocs); + } + + return ret; +} + +static const struct i2c_of_probe_ops i2c_of_probe_dummy_ops; + +/** + * i2c_of_probe_component() - probe for devices of "type" on the same i2c bus + * @dev: Pointer to the &struct device of the caller, only used for dev_printk() messages. + * @cfg: Pointer to the &struct i2c_of_probe_cfg containing callbacks and other options + * for the prober. + * @ctx: Context data for callbacks. + * + * Probe for possible I2C components of the same "type" (&i2c_of_probe_cfg->type) + * on the same I2C bus that have their status marked as "fail-needs-probe". + * + * Assumes that across the entire device tree the only instances of nodes + * with "type" prefixed node names (not including the address portion) are + * the ones that need handling for second source components. In other words, + * if "type" is "touchscreen", then all device nodes named "touchscreen*" + * are the ones that need probing. There cannot be another "touchscreen*" + * node that is already enabled. + * + * Assumes that for each "type" of component, only one actually exists. In + * other words, only one matching and existing device will be enabled. + * + * Context: Process context only. Does non-atomic I2C transfers. + * Should only be used from a driver probe function, as the function + * can return -EPROBE_DEFER if the I2C adapter or other resources + * are unavailable. + * Return: 0 on success or no-op, error code otherwise. + * A no-op can happen when it seems like the device tree already + * has components of the type to be probed already enabled. This + * can happen when the device tree had not been updated to mark + * the status of the to-be-probed components as "fail-needs-probe". + * Or this function was already run with the same parameters and + * succeeded in enabling a component. The latter could happen if + * the user had multiple types of components to probe, and one of + * them down the list caused a deferred probe. This is expected + * behavior. + */ +int i2c_of_probe_component(struct device *dev, const struct i2c_of_probe_cfg *cfg, void *ctx) +{ + const struct i2c_of_probe_ops *ops; + const char *type; + struct i2c_adapter *i2c; + int ret; + + ops = cfg->ops ?: &i2c_of_probe_dummy_ops; + type = cfg->type; + + struct device_node *i2c_node __free(device_node) = i2c_of_probe_get_i2c_node(dev, type); + if (!i2c_node) + return -ENODEV; + + /* + * If any devices of the given "type" are already enabled then this function is a no-op. + * Either the device tree hasn't been modified to work with this probe function, or the + * function had already run before and enabled some component. + */ + for_each_child_of_node_with_prefix(i2c_node, node, type) + if (of_device_is_available(node)) + return 0; + + i2c = of_get_i2c_adapter_by_node(i2c_node); + if (!i2c) + return dev_err_probe(dev, -EPROBE_DEFER, "Couldn't get I2C adapter\n"); + + /* Grab and enable resources */ + ret = 0; + if (ops->enable) + ret = ops->enable(dev, i2c_node, ctx); + if (ret) + goto out_put_i2c_adapter; + + for_each_child_of_node_with_prefix(i2c_node, node, type) { + union i2c_smbus_data data; + u32 addr; + + if (of_property_read_u32(node, "reg", &addr)) + continue; + if (i2c_smbus_xfer(i2c, addr, 0, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data) < 0) + continue; + + /* Found a device that is responding */ + if (ops->cleanup_early) + ops->cleanup_early(dev, ctx); + ret = i2c_of_probe_enable_node(dev, node); + break; + } + + if (ops->cleanup) + ops->cleanup(dev, ctx); +out_put_i2c_adapter: + i2c_put_adapter(i2c); + + return ret; +} +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_component, I2C_OF_PROBER); + +static int i2c_of_probe_simple_get_supply(struct device *dev, struct device_node *node, + struct i2c_of_probe_simple_ctx *ctx) +{ + const char *supply_name; + struct regulator *supply; + + /* + * It's entirely possible for the component's device node to not have the + * regulator supplies. While it does not make sense from a hardware perspective, + * the supplies could be always on or otherwise not modeled in the device tree, + * but the device would still work. + */ + supply_name = ctx->opts->supply_name; + if (!supply_name) + return 0; + + supply = of_regulator_get_optional(dev, node, supply_name); + if (IS_ERR(supply)) { + return dev_err_probe(dev, PTR_ERR(supply), + "Failed to get regulator supply \"%s\" from %pOF\n", + supply_name, node); + } + + ctx->supply = supply; + + return 0; +} + +static void i2c_of_probe_simple_put_supply(struct i2c_of_probe_simple_ctx *ctx) +{ + regulator_put(ctx->supply); + ctx->supply = NULL; +} + +static int i2c_of_probe_simple_enable_regulator(struct device *dev, struct i2c_of_probe_simple_ctx *ctx) +{ + int ret; + + if (!ctx->supply) + return 0; + + dev_dbg(dev, "Enabling regulator supply \"%s\"\n", ctx->opts->supply_name); + + ret = regulator_enable(ctx->supply); + if (ret) + return ret; + + if (ctx->opts->post_power_on_delay_ms) + msleep(ctx->opts->post_power_on_delay_ms); + + return 0; +} + +static void i2c_of_probe_simple_disable_regulator(struct device *dev, struct i2c_of_probe_simple_ctx *ctx) +{ + if (!ctx->supply) + return; + + dev_dbg(dev, "Disabling regulator supply \"%s\"\n", ctx->opts->supply_name); + + regulator_disable(ctx->supply); +} + +static int i2c_of_probe_simple_get_gpiod(struct device *dev, struct device_node *node, + struct i2c_of_probe_simple_ctx *ctx) +{ + struct fwnode_handle *fwnode = of_fwnode_handle(node); + struct gpio_desc *gpiod; + const char *con_id; + + /* NULL signals no GPIO needed */ + if (!ctx->opts->gpio_name) + return 0; + + /* An empty string signals an unnamed GPIO */ + if (!ctx->opts->gpio_name[0]) + con_id = NULL; + else + con_id = ctx->opts->gpio_name; + + gpiod = fwnode_gpiod_get_index(fwnode, con_id, 0, GPIOD_ASIS, "i2c-of-prober"); + if (IS_ERR(gpiod)) + return PTR_ERR(gpiod); + + ctx->gpiod = gpiod; + + return 0; +} + +static void i2c_of_probe_simple_put_gpiod(struct i2c_of_probe_simple_ctx *ctx) +{ + gpiod_put(ctx->gpiod); + ctx->gpiod = NULL; +} + +static int i2c_of_probe_simple_set_gpio(struct device *dev, struct i2c_of_probe_simple_ctx *ctx) +{ + int ret; + + if (!ctx->gpiod) + return 0; + + dev_dbg(dev, "Configuring GPIO\n"); + + ret = gpiod_direction_output(ctx->gpiod, ctx->opts->gpio_assert_to_enable); + if (ret) + return ret; + + if (ctx->opts->post_gpio_config_delay_ms) + msleep(ctx->opts->post_gpio_config_delay_ms); + + return 0; +} + +static void i2c_of_probe_simple_disable_gpio(struct device *dev, struct i2c_of_probe_simple_ctx *ctx) +{ + gpiod_set_value(ctx->gpiod, !ctx->opts->gpio_assert_to_enable); +} + +/** + * i2c_of_probe_simple_enable - Simple helper for I2C OF prober to get and enable resources + * @dev: Pointer to the &struct device of the caller, only used for dev_printk() messages + * @bus_node: Pointer to the &struct device_node of the I2C adapter. + * @data: Pointer to &struct i2c_of_probe_simple_ctx helper context. + * + * If &i2c_of_probe_simple_opts->supply_name is given, request the named regulator supply. + * If &i2c_of_probe_simple_opts->gpio_name is given, request the named GPIO. Or if it is + * the empty string, request the unnamed GPIO. + * If a regulator supply was found, enable that regulator. + * If a GPIO line was found, configure the GPIO line to output and set value + * according to given options. + * + * Return: %0 on success or no-op, or a negative error number on failure. + */ +int i2c_of_probe_simple_enable(struct device *dev, struct device_node *bus_node, void *data) +{ + struct i2c_of_probe_simple_ctx *ctx = data; + struct device_node *node; + const char *compat; + int ret; + + dev_dbg(dev, "Requesting resources for components under I2C bus %pOF\n", bus_node); + + if (!ctx || !ctx->opts) + return -EINVAL; + + compat = ctx->opts->res_node_compatible; + if (!compat) + return -EINVAL; + + node = of_get_compatible_child(bus_node, compat); + if (!node) + return dev_err_probe(dev, -ENODEV, "No device compatible with \"%s\" found\n", + compat); + + ret = i2c_of_probe_simple_get_supply(dev, node, ctx); + if (ret) + goto out_put_node; + + ret = i2c_of_probe_simple_get_gpiod(dev, node, ctx); + if (ret) + goto out_put_supply; + + ret = i2c_of_probe_simple_enable_regulator(dev, ctx); + if (ret) + goto out_put_gpiod; + + ret = i2c_of_probe_simple_set_gpio(dev, ctx); + if (ret) + goto out_disable_regulator; + + return 0; + +out_disable_regulator: + i2c_of_probe_simple_disable_regulator(dev, ctx); +out_put_gpiod: + i2c_of_probe_simple_put_gpiod(ctx); +out_put_supply: + i2c_of_probe_simple_put_supply(ctx); +out_put_node: + of_node_put(node); + return ret; +} +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_enable, I2C_OF_PROBER); + +/** + * i2c_of_probe_simple_cleanup_early - \ + * Simple helper for I2C OF prober to release GPIOs before component is enabled + * @dev: Pointer to the &struct device of the caller; unused. + * @data: Pointer to &struct i2c_of_probe_simple_ctx helper context. + * + * GPIO descriptors are exclusive and have to be released before the + * actual driver probes so that the latter can acquire them. + */ +void i2c_of_probe_simple_cleanup_early(struct device *dev, void *data) +{ + struct i2c_of_probe_simple_ctx *ctx = data; + + i2c_of_probe_simple_put_gpiod(ctx); +} +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_cleanup_early, I2C_OF_PROBER); + +/** + * i2c_of_probe_simple_cleanup - Clean up and release resources for I2C OF prober simple helpers + * @dev: Pointer to the &struct device of the caller, only used for dev_printk() messages + * @data: Pointer to &struct i2c_of_probe_simple_ctx helper context. + * + * * If a GPIO line was found and not yet released, set its value to the opposite of that + * set in i2c_of_probe_simple_enable() and release it. + * * If a regulator supply was found, disable that regulator and release it. + */ +void i2c_of_probe_simple_cleanup(struct device *dev, void *data) +{ + struct i2c_of_probe_simple_ctx *ctx = data; + + /* GPIO operations here are no-ops if i2c_of_probe_simple_cleanup_early was called. */ + i2c_of_probe_simple_disable_gpio(dev, ctx); + i2c_of_probe_simple_put_gpiod(ctx); + + i2c_of_probe_simple_disable_regulator(dev, ctx); + i2c_of_probe_simple_put_supply(ctx); +} +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_cleanup, I2C_OF_PROBER); + +struct i2c_of_probe_ops i2c_of_probe_simple_ops = { + .enable = i2c_of_probe_simple_enable, + .cleanup_early = i2c_of_probe_simple_cleanup_early, + .cleanup = i2c_of_probe_simple_cleanup, +}; +EXPORT_SYMBOL_NS_GPL(i2c_of_probe_simple_ops, I2C_OF_PROBER); diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index 0a6bdc6df172..e73afbefe222 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -122,7 +122,7 @@ EXPORT_SYMBOL(i2c_smbus_read_byte); s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) { return i2c_smbus_xfer(client->adapter, client->addr, client->flags, - I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); + I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); } EXPORT_SYMBOL(i2c_smbus_write_byte); diff --git a/drivers/of/base.c b/drivers/of/base.c index a8b0c42bdc8e..7dc394255a0a 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -644,6 +644,42 @@ struct device_node *of_get_next_child(const struct device_node *node, } EXPORT_SYMBOL(of_get_next_child); +/** + * of_get_next_child_with_prefix - Find the next child node with prefix + * @node: parent node + * @prev: previous child of the parent node, or NULL to get first + * @prefix: prefix that the node name should have + * + * This function is like of_get_next_child(), except that it automatically + * skips any nodes whose name doesn't have the given prefix. + * + * Return: A node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_get_next_child_with_prefix(const struct device_node *node, + struct device_node *prev, + const char *prefix) +{ + struct device_node *next; + unsigned long flags; + + if (!node) + return NULL; + + raw_spin_lock_irqsave(&devtree_lock, flags); + next = prev ? prev->sibling : node->child; + for (; next; next = next->sibling) { + if (!of_node_name_prefix(next, prefix)) + continue; + if (of_node_get(next)) + break; + } + of_node_put(prev); + raw_spin_unlock_irqrestore(&devtree_lock, flags); + return next; +} +EXPORT_SYMBOL(of_get_next_child_with_prefix); + static struct device_node *of_get_next_status_child(const struct device_node *node, struct device_node *prev, bool (*checker)(const struct device_node *)) diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index d45a8df61380..0aba760f7577 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -1072,3 +1072,47 @@ int of_changeset_add_prop_bool(struct of_changeset *ocs, struct device_node *np, return of_changeset_add_prop_helper(ocs, np, &prop); } EXPORT_SYMBOL_GPL(of_changeset_add_prop_bool); + +static int of_changeset_update_prop_helper(struct of_changeset *ocs, + struct device_node *np, + const struct property *pp) +{ + struct property *new_pp; + int ret; + + new_pp = __of_prop_dup(pp, GFP_KERNEL); + if (!new_pp) + return -ENOMEM; + + ret = of_changeset_update_property(ocs, np, new_pp); + if (ret) + __of_prop_free(new_pp); + + return ret; +} + +/** + * of_changeset_update_prop_string - Add a string property update to a changeset + * + * @ocs: changeset pointer + * @np: device node pointer + * @prop_name: name of the property to be updated + * @str: pointer to null terminated string + * + * Create a string property to be updated and add it to a changeset. + * + * Return: 0 on success, a negative error value in case of an error. + */ +int of_changeset_update_prop_string(struct of_changeset *ocs, + struct device_node *np, + const char *prop_name, const char *str) +{ + struct property prop = { + .name = (char *)prop_name, + .length = strlen(str) + 1, + .value = (void *)str, + }; + + return of_changeset_update_prop_helper(ocs, np, &prop); +} +EXPORT_SYMBOL_GPL(of_changeset_update_prop_string); diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig index 7dbeb786352a..b7dbaf77b6db 100644 --- a/drivers/platform/chrome/Kconfig +++ b/drivers/platform/chrome/Kconfig @@ -61,6 +61,17 @@ config CHROMEOS_TBMC To compile this driver as a module, choose M here: the module will be called chromeos_tbmc. +config CHROMEOS_OF_HW_PROBER + tristate "ChromeOS Device Tree Hardware Prober" + depends on OF + depends on I2C + select OF_DYNAMIC + default OF + help + This option enables the device tree hardware prober for ChromeOS + devices. The driver will probe the correct component variant in + devices that have multiple drop-in options for one component. + config CROS_EC tristate "ChromeOS Embedded Controller" select CROS_EC_PROTO diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile index 2dcc6ccc2302..fb8335458a22 100644 --- a/drivers/platform/chrome/Makefile +++ b/drivers/platform/chrome/Makefile @@ -6,6 +6,7 @@ CFLAGS_cros_ec_sensorhub_ring.o:= -I$(src) obj-$(CONFIG_CHROMEOS_ACPI) += chromeos_acpi.o obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o +obj-$(CONFIG_CHROMEOS_OF_HW_PROBER) += chromeos_of_hw_prober.o obj-$(CONFIG_CHROMEOS_PRIVACY_SCREEN) += chromeos_privacy_screen.o obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o diff --git a/drivers/platform/chrome/chromeos_of_hw_prober.c b/drivers/platform/chrome/chromeos_of_hw_prober.c new file mode 100644 index 000000000000..297d4704b75f --- /dev/null +++ b/drivers/platform/chrome/chromeos_of_hw_prober.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ChromeOS Device Tree Hardware Prober + * + * Copyright (c) 2024 Google LLC + */ + +#include <linux/array_size.h> +#include <linux/errno.h> +#include <linux/i2c-of-prober.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/stddef.h> + +#define DRV_NAME "chromeos_of_hw_prober" + +/** + * struct hw_prober_entry - Holds an entry for the hardware prober + * + * @compatible: compatible string to match against the machine + * @prober: prober function to call when machine matches + * @data: extra data for the prober function + */ +struct hw_prober_entry { + const char *compatible; + int (*prober)(struct device *dev, const void *data); + const void *data; +}; + +struct chromeos_i2c_probe_data { + const struct i2c_of_probe_cfg *cfg; + const struct i2c_of_probe_simple_opts *opts; +}; + +static int chromeos_i2c_component_prober(struct device *dev, const void *_data) +{ + const struct chromeos_i2c_probe_data *data = _data; + struct i2c_of_probe_simple_ctx ctx = { + .opts = data->opts, + }; + + return i2c_of_probe_component(dev, data->cfg, &ctx); +} + +#define DEFINE_CHROMEOS_I2C_PROBE_CFG_SIMPLE_BY_TYPE(_type) \ + static const struct i2c_of_probe_cfg chromeos_i2c_probe_simple_ ## _type ## _cfg = { \ + .type = #_type, \ + .ops = &i2c_of_probe_simple_ops, \ + } + +#define DEFINE_CHROMEOS_I2C_PROBE_DATA_DUMB_BY_TYPE(_type) \ + static const struct chromeos_i2c_probe_data chromeos_i2c_probe_dumb_ ## _type = { \ + .cfg = &(const struct i2c_of_probe_cfg) { \ + .type = #_type, \ + }, \ + } + +DEFINE_CHROMEOS_I2C_PROBE_DATA_DUMB_BY_TYPE(touchscreen); + +DEFINE_CHROMEOS_I2C_PROBE_CFG_SIMPLE_BY_TYPE(trackpad); + +static const struct chromeos_i2c_probe_data chromeos_i2c_probe_hana_trackpad = { + .cfg = &chromeos_i2c_probe_simple_trackpad_cfg, + .opts = &(const struct i2c_of_probe_simple_opts) { + .res_node_compatible = "elan,ekth3000", + .supply_name = "vcc", + /* + * ELAN trackpad needs 2 ms for H/W init and 100 ms for F/W init. + * Synaptics trackpad needs 100 ms. + * However, the regulator is set to "always-on", presumably to + * avoid this delay. The ELAN driver is also missing delays. + */ + .post_power_on_delay_ms = 0, + }, +}; + +static const struct hw_prober_entry hw_prober_platforms[] = { + { + .compatible = "google,hana", + .prober = chromeos_i2c_component_prober, + .data = &chromeos_i2c_probe_dumb_touchscreen, + }, { + .compatible = "google,hana", + .prober = chromeos_i2c_component_prober, + .data = &chromeos_i2c_probe_hana_trackpad, + }, +}; + +static int chromeos_of_hw_prober_probe(struct platform_device *pdev) +{ + for (size_t i = 0; i < ARRAY_SIZE(hw_prober_platforms); i++) { + int ret; + + if (!of_machine_is_compatible(hw_prober_platforms[i].compatible)) + continue; + + ret = hw_prober_platforms[i].prober(&pdev->dev, hw_prober_platforms[i].data); + /* Ignore unrecoverable errors and keep going through other probers */ + if (ret == -EPROBE_DEFER) + return ret; + } + + return 0; +} + +static struct platform_driver chromeos_of_hw_prober_driver = { + .probe = chromeos_of_hw_prober_probe, + .driver = { + .name = DRV_NAME, + }, +}; + +static struct platform_device *chromeos_of_hw_prober_pdev; + +static int chromeos_of_hw_prober_driver_init(void) +{ + size_t i; + int ret; + + for (i = 0; i < ARRAY_SIZE(hw_prober_platforms); i++) + if (of_machine_is_compatible(hw_prober_platforms[i].compatible)) + break; + if (i == ARRAY_SIZE(hw_prober_platforms)) + return -ENODEV; + + ret = platform_driver_register(&chromeos_of_hw_prober_driver); + if (ret) + return ret; + + chromeos_of_hw_prober_pdev = + platform_device_register_simple(DRV_NAME, PLATFORM_DEVID_NONE, NULL, 0); + if (IS_ERR(chromeos_of_hw_prober_pdev)) + goto err; + + return 0; + +err: + platform_driver_unregister(&chromeos_of_hw_prober_driver); + + return PTR_ERR(chromeos_of_hw_prober_pdev); +} +module_init(chromeos_of_hw_prober_driver_init); + +static void chromeos_of_hw_prober_driver_exit(void) +{ + platform_device_unregister(chromeos_of_hw_prober_pdev); + platform_driver_unregister(&chromeos_of_hw_prober_driver); +} +module_exit(chromeos_of_hw_prober_driver_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ChromeOS device tree hardware prober"); +MODULE_IMPORT_NS(I2C_OF_PROBER); diff --git a/include/linux/i2c-of-prober.h b/include/linux/i2c-of-prober.h new file mode 100644 index 000000000000..bb6d47f50ee5 --- /dev/null +++ b/include/linux/i2c-of-prober.h @@ -0,0 +1,140 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Definitions for the Linux I2C OF component prober + * + * Copyright (C) 2024 Google LLC + */ + +#ifndef _LINUX_I2C_OF_PROBER_H +#define _LINUX_I2C_OF_PROBER_H + +#include <linux/kconfig.h> +#include <linux/types.h> + +struct device; +struct device_node; + +/** + * struct i2c_of_probe_ops - I2C OF component prober callbacks + * + * A set of callbacks to be used by i2c_of_probe_component(). + * + * All callbacks are optional. Callbacks are called only once per run, and are + * used in the order they are defined in this structure. + * + * All callbacks that have return values shall return %0 on success, + * or a negative error number on failure. + * + * The @dev parameter passed to the callbacks is the same as @dev passed to + * i2c_of_probe_component(). It should only be used for dev_printk() calls + * and nothing else, especially not managed device resource (devres) APIs. + */ +struct i2c_of_probe_ops { + /** + * @enable: Retrieve and enable resources so that the components respond to probes. + * + * It is OK for this callback to return -EPROBE_DEFER since the intended use includes + * retrieving resources and enables them. Resources should be reverted to their initial + * state and released before returning if this fails. + */ + int (*enable)(struct device *dev, struct device_node *bus_node, void *data); + + /** + * @cleanup_early: Release exclusive resources prior to calling probe() on a + * detected component. + * + * Only called if a matching component is actually found. If none are found, + * resources that would have been released in this callback should be released in + * @free_resourcs_late instead. + */ + void (*cleanup_early)(struct device *dev, void *data); + + /** + * @cleanup: Opposite of @enable to balance refcounts and free resources after probing. + * + * Should check if resources were already freed by @cleanup_early. + */ + void (*cleanup)(struct device *dev, void *data); +}; + +/** + * struct i2c_of_probe_cfg - I2C OF component prober configuration + * @ops: Callbacks for the prober to use. + * @type: A string to match the device node name prefix to probe for. + */ +struct i2c_of_probe_cfg { + const struct i2c_of_probe_ops *ops; + const char *type; +}; + +#if IS_ENABLED(CONFIG_OF_DYNAMIC) + +int i2c_of_probe_component(struct device *dev, const struct i2c_of_probe_cfg *cfg, void *ctx); + +/** + * DOC: I2C OF component prober simple helpers + * + * Components such as trackpads are commonly connected to a devices baseboard + * with a 6-pin ribbon cable. That gives at most one voltage supply and one + * GPIO (commonly a "enable" or "reset" line) besides the I2C bus, interrupt + * pin, and common ground. Touchscreens, while integrated into the display + * panel's connection, typically have the same set of connections. + * + * A simple set of helpers are provided here for use with the I2C OF component + * prober. This implementation targets such components, allowing for at most + * one regulator supply. + * + * The following helpers are provided: + * * i2c_of_probe_simple_enable() + * * i2c_of_probe_simple_cleanup_early() + * * i2c_of_probe_simple_cleanup() + */ + +/** + * struct i2c_of_probe_simple_opts - Options for simple I2C component prober callbacks + * @res_node_compatible: Compatible string of device node to retrieve resources from. + * @supply_name: Name of regulator supply. + * @gpio_name: Name of GPIO. NULL if no GPIO line is used. Empty string ("") if GPIO + * line is unnamed. + * @post_power_on_delay_ms: Delay after regulators are powered on. Passed to msleep(). + * @post_gpio_config_delay_ms: Delay after GPIO is configured. Passed to msleep(). + * @gpio_assert_to_enable: %true if GPIO should be asserted, i.e. set to logical high, + * to enable the component. + * + * This describes power sequences common for the class of components supported by the + * simple component prober: + * * @gpio_name is configured to the non-active setting according to @gpio_assert_to_enable. + * * @supply_name regulator supply is enabled. + * * Wait for @post_power_on_delay_ms to pass. + * * @gpio_name is configured to the active setting according to @gpio_assert_to_enable. + * * Wait for @post_gpio_config_delay_ms to pass. + */ +struct i2c_of_probe_simple_opts { + const char *res_node_compatible; + const char *supply_name; + const char *gpio_name; + unsigned int post_power_on_delay_ms; + unsigned int post_gpio_config_delay_ms; + bool gpio_assert_to_enable; +}; + +struct gpio_desc; +struct regulator; + +struct i2c_of_probe_simple_ctx { + /* public: provided by user before helpers are used. */ + const struct i2c_of_probe_simple_opts *opts; + /* private: internal fields for helpers. */ + struct regulator *supply; + struct gpio_desc *gpiod; +}; + +int i2c_of_probe_simple_enable(struct device *dev, struct device_node *bus_node, void *data); +void i2c_of_probe_simple_cleanup_early(struct device *dev, void *data); +void i2c_of_probe_simple_cleanup(struct device *dev, void *data); + +extern struct i2c_of_probe_ops i2c_of_probe_simple_ops; + +#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ + +#endif /* _LINUX_I2C_OF_PROBER_H */ diff --git a/include/linux/of.h b/include/linux/of.h index 086a60f3b8a6..f921786cb8ac 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -289,6 +289,9 @@ extern struct device_node *of_get_parent(const struct device_node *node); extern struct device_node *of_get_next_parent(struct device_node *node); extern struct device_node *of_get_next_child(const struct device_node *node, struct device_node *prev); +extern struct device_node *of_get_next_child_with_prefix(const struct device_node *node, + struct device_node *prev, + const char *prefix); extern struct device_node *of_get_next_available_child( const struct device_node *node, struct device_node *prev); extern struct device_node *of_get_next_reserved_child( @@ -1468,6 +1471,12 @@ static inline int of_property_read_s32(const struct device_node *np, child != NULL; \ child = of_get_next_child(parent, child)) +#define for_each_child_of_node_with_prefix(parent, child, prefix) \ + for (struct device_node *child __free(device_node) = \ + of_get_next_child_with_prefix(parent, NULL, prefix); \ + child != NULL; \ + child = of_get_next_child_with_prefix(parent, child, prefix)) + #define for_each_available_child_of_node(parent, child) \ for (child = of_get_next_available_child(parent, NULL); child != NULL; \ child = of_get_next_available_child(parent, child)) @@ -1651,6 +1660,10 @@ static inline int of_changeset_add_prop_u32(struct of_changeset *ocs, return of_changeset_add_prop_u32_array(ocs, np, prop_name, &val, 1); } +int of_changeset_update_prop_string(struct of_changeset *ocs, + struct device_node *np, + const char *prop_name, const char *str); + int of_changeset_add_prop_bool(struct of_changeset *ocs, struct device_node *np, const char *prop_name); |