Many I2C devices produce roughly the same ACPI data with just things like the GPIO/interrupt information being different.
This can be handled by a generic driver along with some information in the device tree.
Add a generic i2c driver for this purpose.
Signed-off-by: Simon Glass sjg@chromium.org ---
doc/device-tree-bindings/i2c/generic-acpi.txt | 42 ++++ drivers/i2c/Makefile | 3 + drivers/i2c/acpi_i2c.c | 228 ++++++++++++++++++ drivers/i2c/acpi_i2c.h | 15 ++ drivers/i2c/i2c-uclass.c | 14 ++ include/i2c.h | 17 ++ 6 files changed, 319 insertions(+) create mode 100644 doc/device-tree-bindings/i2c/generic-acpi.txt create mode 100644 drivers/i2c/acpi_i2c.c create mode 100644 drivers/i2c/acpi_i2c.h
diff --git a/doc/device-tree-bindings/i2c/generic-acpi.txt b/doc/device-tree-bindings/i2c/generic-acpi.txt new file mode 100644 index 0000000000..b1a4e8d752 --- /dev/null +++ b/doc/device-tree-bindings/i2c/generic-acpi.txt @@ -0,0 +1,42 @@ +I2C generic device +================== + +This is used only to generate ACPI tables for an I2C device. + +Required properties : + + - compatible : "i2c-chip"; + - reg : I2C chip address + - acpi,hid : HID name for the device + +Optional properies in addition to device.txt: + + - reset-gpios : GPIO used to assert reset to the device + - irq-gpios : GPIO used for interrupt (if Interrupt is not used) + - stop-gpios : GPIO used to stop the device + - interrupts-extended : Interrupt to use for the device + - reset-delay-ms : Delay after de-asserting reset, in ms + - reset-off-delay-ms : Delay after asserting reset (during power off) + - enable-delay-ms : Delay after asserting enable + - enable-off-delay-m s: Delay after de-asserting enable (during power off) + - stop-delay-ms : Delay after de-aserting stop + - stop-off-delay-ms : Delay after asserting stop (during power off) + - acpi,hid-desc-reg-offset : HID register offset (for Human Interface Devices) + +Example +------- + + elan-touchscreen@10 { + compatible = "i2c-chip"; + reg = <0x10>; + acpi,hid = "ELAN0001"; + acpi,desc = "ELAN Touchscreen"; + interrupts-extended = <&acpi_gpe GPIO_21_IRQ + IRQ_TYPE_EDGE_FALLING>; + acpi,probed; + reset-gpios = <&gpio_n GPIO_36 GPIO_ACTIVE_HIGH>; + reset-delay-ms = <20>; + enable-gpios = <&gpio_n GPIO_152 GPIO_ACTIVE_HIGH>; + enable-delay-ms = <1>; + acpi,has-power-resource; + }; diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index f5a471f887..43e58b8cac 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -3,6 +3,9 @@ # (C) Copyright 2000-2007 # Wolfgang Denk, DENX Software Engineering, wd@denx.de. obj-$(CONFIG_DM_I2C) += i2c-uclass.o +ifdef CONFIG_ACPIGEN +obj-$(CONFIG_DM_I2C) += acpi_i2c.o +endif obj-$(CONFIG_DM_I2C_GPIO) += i2c-gpio.o obj-$(CONFIG_$(SPL_)I2C_CROS_EC_TUNNEL) += cros_ec_tunnel.o obj-$(CONFIG_$(SPL_)I2C_CROS_EC_LDO) += cros_ec_ldo.o diff --git a/drivers/i2c/acpi_i2c.c b/drivers/i2c/acpi_i2c.c new file mode 100644 index 0000000000..53609b2137 --- /dev/null +++ b/drivers/i2c/acpi_i2c.c @@ -0,0 +1,228 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2019 Google LLC + */ + +#include <common.h> +#include <acpi_device.h> +#include <acpigen.h> +#include <dm.h> +#include <i2c.h> +#include <asm-generic/gpio.h> +#include <dm/acpi.h> + +static bool acpi_i2c_add_gpios_to_crs(struct acpi_i2c_priv *priv) +{ + /* + * Return false if: + * 1. Request to explicitly disable export of GPIOs in CRS, or + * 2. Both reset and enable GPIOs are not provided. + */ + if (priv->disable_gpio_export_in_crs || + (!dm_gpio_is_valid(&priv->reset_gpio) && + !dm_gpio_is_valid(&priv->enable_gpio))) + return false; + + return true; +} + +static int acpi_i2c_write_gpio(struct acpi_ctx *ctx, struct gpio_desc *gpio, + int *curindex) +{ + int ret; + + if (!dm_gpio_is_valid(gpio)) + return -ENOENT; + + acpi_device_write_gpio_desc(ctx, gpio); + ret = *curindex; + (*curindex)++; + + return ret; +} + +int acpi_i2c_fill_ssdt(const struct udevice *dev, struct acpi_ctx *ctx) +{ + int reset_gpio_index = -1, enable_gpio_index = -1, irq_gpio_index = -1; + struct acpi_i2c_priv *priv = dev_get_priv(dev); + char scope[ACPI_PATH_MAX]; + char name[ACPI_NAME_MAX]; + struct acpi_dp *dsd = NULL; + int curindex = 0; + int ret; + + ret = acpi_device_name(dev, name); + if (ret) + return log_msg_ret("name", ret); + ret = acpi_device_scope(dev, scope, sizeof(scope)); + if (ret) + return log_msg_ret("scope", ret); + + /* Device */ + acpigen_write_scope(ctx, scope); + acpigen_write_device(ctx, name); + acpigen_write_name_string(ctx, "_HID", priv->hid); + if (priv->cid) + acpigen_write_name_string(ctx, "_CID", priv->cid); + acpigen_write_name_integer(ctx, "_UID", priv->uid); + acpigen_write_name_string(ctx, "_DDN", priv->desc); + acpigen_write_sta(ctx, acpi_device_status(dev)); + + /* Resources */ + acpigen_write_name(ctx, "_CRS"); + acpigen_write_resourcetemplate_header(ctx); + acpi_device_write_i2c_dev(ctx, dev); + + /* Use either Interrupt() or GpioInt() */ + if (dm_gpio_is_valid(&priv->irq_gpio)) { + irq_gpio_index = acpi_i2c_write_gpio(ctx, &priv->irq_gpio, + &curindex); + } else { + ret = acpi_device_write_interrupt_irq(ctx, &priv->irq); + if (ret) + return log_msg_ret("irq", ret); + } + + if (acpi_i2c_add_gpios_to_crs(priv)) { + reset_gpio_index = acpi_i2c_write_gpio(ctx, &priv->reset_gpio, + &curindex); + enable_gpio_index = acpi_i2c_write_gpio(ctx, &priv->enable_gpio, + &curindex); + } + acpigen_write_resourcetemplate_footer(ctx); + + /* Wake capabilities */ + if (priv->wake) { + acpigen_write_name_integer(ctx, "_S0W", 4); + acpigen_write_prw(ctx, priv->wake, 3); + } + + /* DSD */ + if (priv->probed || priv->property_count || priv->compat_string || + reset_gpio_index >= 0 || enable_gpio_index >= 0 || + irq_gpio_index >= 0) { + char path[ACPI_PATH_MAX]; + + ret = acpi_device_path(dev, path, sizeof(path)); + if (ret) + return log_msg_ret("path", ret); + + dsd = acpi_dp_new_table("_DSD"); + if (priv->compat_string) + acpi_dp_add_string(dsd, "compatible", + priv->compat_string); + if (priv->probed) + acpi_dp_add_integer(dsd, "linux,probed", 1); + if (irq_gpio_index >= 0) + acpi_dp_add_gpio(dsd, "irq-gpios", path, + irq_gpio_index, 0, + priv->irq_gpio.flags & + GPIOD_ACTIVE_LOW ? + ACPI_GPIO_ACTIVE_LOW : 0); + if (reset_gpio_index >= 0) + acpi_dp_add_gpio(dsd, "reset-gpios", path, + reset_gpio_index, 0, + priv->reset_gpio.flags & + GPIOD_ACTIVE_LOW ? + ACPI_GPIO_ACTIVE_LOW : 0); + if (enable_gpio_index >= 0) + acpi_dp_add_gpio(dsd, "enable-gpios", path, + enable_gpio_index, 0, + priv->enable_gpio.flags & + GPIOD_ACTIVE_LOW ? + ACPI_GPIO_ACTIVE_LOW : 0); + /* Add generic property list (not supported) */ + assert(!priv->property_count); + acpi_dp_add_property_list(dsd, NULL, priv->property_count); + acpi_dp_write(ctx, dsd); + } + + /* Power Resource */ + if (priv->has_power_resource) { + struct acpi_gpio reset_gpio, enable_gpio, stop_gpio; + + gpio_get_acpi(&priv->reset_gpio, &reset_gpio); + gpio_get_acpi(&priv->enable_gpio, &enable_gpio); + gpio_get_acpi(&priv->stop_gpio, &stop_gpio); + const struct acpi_power_res_params power_res_params = { + &reset_gpio, + priv->reset_delay_ms, + priv->reset_off_delay_ms, + &enable_gpio, + priv->enable_delay_ms, + priv->enable_off_delay_ms, + &stop_gpio, + priv->stop_delay_ms, + priv->stop_off_delay_ms + }; + ret = acpi_device_add_power_res(ctx, &power_res_params); + if (ret) + return log_msg_ret("power", ret); + } + if (priv->hid_desc_reg_offset) { + struct dsm_i2c_hid_config dsm_config = { + .hid_desc_reg_offset = priv->hid_desc_reg_offset, + }; + + acpi_device_write_dsm_i2c_hid(ctx, &dsm_config); + } + + acpigen_pop_len(ctx); /* Device */ + acpigen_pop_len(ctx); /* Scope */ + + return 0; +} + +int acpi_i2c_ofdata_to_platdata(struct udevice *dev) +{ + struct acpi_i2c_priv *priv = dev_get_priv(dev); + + gpio_request_by_name(dev, "reset-gpios", 0, &priv->reset_gpio, + GPIOD_IS_OUT); + gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable_gpio, + GPIOD_IS_OUT); + gpio_request_by_name(dev, "irq-gpios", 0, &priv->irq_gpio, GPIOD_IS_IN); + gpio_request_by_name(dev, "stop-gpios", 0, &priv->stop_gpio, + GPIOD_IS_OUT); + irq_get_by_index(dev, 0, &priv->irq); + priv->hid = dev_read_string(dev, "acpi,hid"); + if (!priv->hid) + return log_msg_ret("hid", -EINVAL); + priv->cid = dev_read_string(dev, "acpi,cid"); + dev_read_u32(dev, "acpi,uid", &priv->uid); + priv->desc = dev_read_string(dev, "acpi,desc"); + dev_read_u32(dev, "acpi,wake", &priv->wake); + priv->probed = dev_read_bool(dev, "acpi,probed"); + priv->compat_string = dev_read_string(dev, "acpi,compatible"); + priv->has_power_resource = dev_read_bool(dev, + "acpi,has-power-resource"); + dev_read_u32(dev, "acpi,hid-desc-reg-offset", + &priv->hid_desc_reg_offset); + dev_read_u32(dev, "reset-delay-ms", &priv->reset_delay_ms); + dev_read_u32(dev, "reset-off-delay-ms", &priv->reset_off_delay_ms); + dev_read_u32(dev, "enable-delay-ms", &priv->enable_delay_ms); + dev_read_u32(dev, "enable-off-delay-ms", &priv->enable_off_delay_ms); + dev_read_u32(dev, "stop-delay-ms", &priv->stop_delay_ms); + dev_read_u32(dev, "stop-off-delay-ms", &priv->stop_off_delay_ms); + dev_read_u32(dev, "stop-off-delay-ms", &priv->hid_desc_reg_offset); + + return 0; +} + +/* Use name specified in priv or build one from I2C address */ +static int acpi_i2c_get_name(const struct udevice *dev, char *out_name) +{ + struct dm_i2c_chip *chip = dev_get_parent_platdata(dev); + struct acpi_i2c_priv *priv = dev_get_priv(dev); + + snprintf(out_name, ACPI_NAME_MAX, + priv->hid_desc_reg_offset ? "H%03X" : "D%03X", + chip->chip_addr); + + return 0; +} + +struct acpi_ops acpi_i2c_ops = { + .fill_ssdt = acpi_i2c_fill_ssdt, + .get_name = acpi_i2c_get_name, +}; diff --git a/drivers/i2c/acpi_i2c.h b/drivers/i2c/acpi_i2c.h new file mode 100644 index 0000000000..1f4be29601 --- /dev/null +++ b/drivers/i2c/acpi_i2c.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright 2019 Google LLC + */ + +#ifndef __ACPI_I2C_H +#define __ACPI_I2C_H + +#include <dm/acpi.h> + +extern struct acpi_ops acpi_i2c_ops; + +int acpi_i2c_ofdata_to_platdata(struct udevice *dev); + +#endif diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c index a577988bfb..5a3bee57b9 100644 --- a/drivers/i2c/i2c-uclass.c +++ b/drivers/i2c/i2c-uclass.c @@ -4,16 +4,19 @@ */
#include <common.h> +#include <acpi_device.h> #include <dm.h> #include <errno.h> #include <i2c.h> #include <malloc.h> +#include <dm/acpi.h> #include <dm/device-internal.h> #include <dm/lists.h> #include <dm/pinctrl.h> #if CONFIG_IS_ENABLED(DM_GPIO) #include <asm/gpio.h> #endif +#include "acpi_i2c.h"
#define I2C_MAX_OFFSET_LEN 4
@@ -728,7 +731,18 @@ UCLASS_DRIVER(i2c_generic) = { .name = "i2c_generic", };
+static const struct udevice_id generic_chip_i2c_ids[] = { + { .compatible = "i2c-chip" }, + { } +}; + U_BOOT_DRIVER(i2c_generic_chip_drv) = { .name = "i2c_generic_chip_drv", .id = UCLASS_I2C_GENERIC, + .of_match = generic_chip_i2c_ids, +#if CONFIG_IS_ENABLED(ACPIGEN) + .ofdata_to_platdata = acpi_i2c_ofdata_to_platdata, + .priv_auto_alloc_size = sizeof(struct acpi_i2c_priv), +#endif + acpi_ops_ptr(&acpi_i2c_ops) }; diff --git a/include/i2c.h b/include/i2c.h index 41ee5875e7..721b4305dd 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -538,6 +538,23 @@ int i2c_emul_find(struct udevice *dev, struct udevice **emulp); */ struct udevice *i2c_emul_get_device(struct udevice *emul);
+/* ACPI operations for generic I2C devices */ +extern struct acpi_ops i2c_acpi_ops; + +/** + * acpi_i2c_ofdata_to_platdata() - Read properties intended for ACPI + * + * This reads the generic I2C properties from the device tree, so that these + * can be used to create ACPI information for the device. + * + * See the i2c/generic-acpi.txt binding file for information about the + * properties. + * + * @dev: I2C device to process + * @return 0 if OK, -EINVAL if acpi,hid is not present + */ +int acpi_i2c_ofdata_to_platdata(struct udevice *dev); + #ifndef CONFIG_DM_I2C
/*