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 Reviewed-by: Heiko Schocher hs@denx.de ---
(no changes since v2)
Changes in v2: - Fix incorrect space in enable-off-delay-ms
Changes in v1: - Adjust implementation to match new ACPI GPIO generation - Capitalise ACPI_OPS_PTR - Rename acpi-probed to linux,probed - Support hid-over-i2c separately as well - Use acpi,ddn instead of acpi,desc - Use updated acpi_device_write_dsm_i2c_hid() function
doc/device-tree-bindings/i2c/generic-acpi.txt | 42 ++++ drivers/i2c/Makefile | 3 + drivers/i2c/acpi_i2c.c | 226 ++++++++++++++++++ drivers/i2c/acpi_i2c.h | 15 ++ drivers/i2c/i2c-uclass.c | 17 ++ include/acpi/acpi_device.h | 55 +++++ include/i2c.h | 23 ++ 7 files changed, 381 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 00000000000..3510a71b570 --- /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-ms : 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) + - hid-descr-addr : HID register offset (for Human Interface Devices) + +Example +------- + + elan-touchscreen@10 { + compatible = "i2c-chip"; + reg = <0x10>; + acpi,hid = "ELAN0001"; + acpi,ddn = "ELAN Touchscreen"; + interrupts-extended = <&acpi_gpe GPIO_21_IRQ + IRQ_TYPE_EDGE_FALLING>; + linux,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 f7b27864488..bd248cbf52b 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 00000000000..57d29683cbf --- /dev/null +++ b/drivers/i2c/acpi_i2c.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2019 Google LLC + */ + +#include <common.h> +#include <dm.h> +#include <i2c.h> +#include <log.h> +#include <acpi/acpi_device.h> +#include <acpi/acpigen.h> +#include <acpi/acpi_dp.h> +#ifdef CONFIG_X86 +#include <asm/intel_pinctrl_defs.h> +#endif +#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; + enum i2c_device_t type = dev_get_driver_data(dev); + struct acpi_i2c_priv *priv = dev_get_priv(dev); + struct acpi_dp *dsd = NULL; + char scope[ACPI_PATH_MAX]; + char name[ACPI_NAME_MAX]; + int tx_state_val; + int curindex = 0; + int ret; + +#ifdef CONFIG_X86 + tx_state_val = PAD_CFG0_TX_STATE; +#elif defined(CONFIG_SANDBOX) + tx_state_val = BIT(7); /* test value */ +#else +#error "Not supported on this architecture" +#endif + ret = acpi_get_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 (type == I2C_DEVICE_HID_OVER_I2C) + acpigen_write_name_string(ctx, "_CID", "PNP0C50"); + 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 < 0) + 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); + /* Generic property list is not supported */ + acpi_dp_write(ctx, dsd); + } + + /* Power Resource */ + if (priv->has_power_resource) { + ret = acpi_device_add_power_res(ctx, tx_state_val, + "\_SB.GPC0", "\_SB.SPC0", + &priv->reset_gpio, priv->reset_delay_ms, + priv->reset_off_delay_ms, &priv->enable_gpio, + priv->enable_delay_ms, priv->enable_off_delay_ms, + &priv->stop_gpio, priv->stop_delay_ms, + priv->stop_off_delay_ms); + if (ret) + return log_msg_ret("power", ret); + } + if (priv->hid_desc_reg_offset) { + ret = acpi_device_write_dsm_i2c_hid(ctx, + priv->hid_desc_reg_offset); + if (ret) + return log_msg_ret("dsm", ret); + } + + 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); + dev_read_u32(dev, "acpi,uid", &priv->uid); + priv->desc = dev_read_string(dev, "acpi,ddn"); + dev_read_u32(dev, "acpi,wake", &priv->wake); + priv->probed = dev_read_bool(dev, "linux,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, "hid-descr-addr", &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); + + 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 00000000000..1f4be296016 --- /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 2373aa2ea4c..5c4626b0442 100644 --- a/drivers/i2c/i2c-uclass.c +++ b/drivers/i2c/i2c-uclass.c @@ -9,6 +9,8 @@ #include <i2c.h> #include <log.h> #include <malloc.h> +#include <acpi/acpi_device.h> +#include <dm/acpi.h> #include <dm/device-internal.h> #include <dm/lists.h> #include <dm/pinctrl.h> @@ -16,6 +18,7 @@ #include <asm/gpio.h> #endif #include <linux/delay.h> +#include "acpi_i2c.h"
#define I2C_MAX_OFFSET_LEN 4
@@ -749,7 +752,21 @@ UCLASS_DRIVER(i2c_generic) = { .name = "i2c_generic", };
+static const struct udevice_id generic_chip_i2c_ids[] = { + { .compatible = "i2c-chip", .data = I2C_DEVICE_GENERIC }, +#if CONFIG_IS_ENABLED(ACPIGEN) + { .compatible = "hid-over-i2c", .data = I2C_DEVICE_HID_OVER_I2C }, +#endif + { } +}; + 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/acpi/acpi_device.h b/include/acpi/acpi_device.h index a5b12217820..1b838fcb857 100644 --- a/include/acpi/acpi_device.h +++ b/include/acpi/acpi_device.h @@ -10,7 +10,9 @@ #define __ACPI_DEVICE_H
#include <i2c.h> +#include <irq.h> #include <spi.h> +#include <asm-generic/gpio.h> #include <linux/bitops.h>
struct acpi_ctx; @@ -235,6 +237,59 @@ struct acpi_spi { const char *resource; };
+/** + * struct acpi_i2c_priv - Information read from device tree + * + * This is used by devices which want to specify various pieces of ACPI + * information, including power control. It allows a generic function to + * generate the information for ACPI, based on device-tree properties. + * + * @disable_gpio_export_in_crs: Don't export GPIOs in the CRS + * @reset_gpio: GPIO used to assert reset to the device + * @enable_gpio: GPIO used to enable the device + * @stop_gpio: GPIO used to stop the device + * @irq_gpio: GPIO used for interrupt (if @irq is not used) + * @irq: IRQ used for interrupt (if @irq_gpio is not used) + * @hid: _HID value for device (required) + * @uid: _UID value for device + * @desc: _DDN value for device + * @wake: Wake event, e.g. GPE0_DW1_15; 0 if none + * @property_count: Number of other DSD properties (currently always 0) + * @probed: true set set 'linux,probed' property + * @compat_string: Device tree compatible string to report through ACPI + * @has_power_resource: true if this device has a power resource + * @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_ms: 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) + * @hid_desc_reg_offset: HID register offset (for Human Interface Devices) + */ +struct acpi_i2c_priv { + bool disable_gpio_export_in_crs; + struct gpio_desc reset_gpio; + struct gpio_desc enable_gpio; + struct gpio_desc irq_gpio; + struct gpio_desc stop_gpio; + struct irq irq; + const char *hid; + u32 uid; + const char *desc; + u32 wake; + u32 property_count; + bool probed; + const char *compat_string; + bool has_power_resource; + u32 reset_delay_ms; + u32 reset_off_delay_ms; + u32 enable_delay_ms; + u32 enable_off_delay_ms; + u32 stop_delay_ms; + u32 stop_off_delay_ms; + u32 hid_desc_reg_offset; +}; + /** * acpi_device_path() - Get the full path to an ACPI device * diff --git a/include/i2c.h b/include/i2c.h index 1d792db454a..880aa8032b7 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -58,6 +58,12 @@ enum i2c_address_mode { I2C_MODE_10_BIT };
+/** enum i2c_device_t - Types of I2C devices, used for compatible strings */ +enum i2c_device_t { + I2C_DEVICE_GENERIC, + I2C_DEVICE_HID_OVER_I2C, +}; + struct udevice; /** * struct dm_i2c_chip - information about an i2c chip @@ -558,6 +564,23 @@ 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
/*