diff options
Diffstat (limited to 'src/drivers/i2c/generic')
| -rw-r--r-- | src/drivers/i2c/generic/Kconfig | 2 | ||||
| -rw-r--r-- | src/drivers/i2c/generic/Makefile.inc | 1 | ||||
| -rw-r--r-- | src/drivers/i2c/generic/chip.h | 16 | ||||
| -rw-r--r-- | src/drivers/i2c/generic/generic.c | 124 |
4 files changed, 143 insertions, 0 deletions
diff --git a/src/drivers/i2c/generic/Kconfig b/src/drivers/i2c/generic/Kconfig new file mode 100644 index 0000000000..a4c01048aa --- /dev/null +++ b/src/drivers/i2c/generic/Kconfig @@ -0,0 +1,2 @@ +config DRIVERS_I2C_GENERIC + bool diff --git a/src/drivers/i2c/generic/Makefile.inc b/src/drivers/i2c/generic/Makefile.inc new file mode 100644 index 0000000000..86cbc7bdc3 --- /dev/null +++ b/src/drivers/i2c/generic/Makefile.inc @@ -0,0 +1 @@ +ramstage-$(CONFIG_DRIVERS_I2C_GENERIC) += generic.c diff --git a/src/drivers/i2c/generic/chip.h b/src/drivers/i2c/generic/chip.h new file mode 100644 index 0000000000..84657d5241 --- /dev/null +++ b/src/drivers/i2c/generic/chip.h @@ -0,0 +1,16 @@ +#include <arch/acpi_device.h> +#include <device/i2c.h> + +struct drivers_i2c_generic_config { + const char *hid; /* ACPI _HID (required) */ + const char *name; /* ACPI Device Name */ + const char *desc; /* Device Description */ + unsigned uid; /* ACPI _UID */ + enum i2c_speed speed; /* Bus speed in Hz, default is I2C_SPEED_FAST */ + unsigned wake; /* Wake GPE */ + struct acpi_irq irq; /* Interrupt */ + + /* GPIO used to indicate if this device is present */ + unsigned device_present_gpio; + unsigned device_present_gpio_invert; +}; diff --git a/src/drivers/i2c/generic/generic.c b/src/drivers/i2c/generic/generic.c new file mode 100644 index 0000000000..1c10b0e3cf --- /dev/null +++ b/src/drivers/i2c/generic/generic.c @@ -0,0 +1,124 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2016 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <arch/acpi_device.h> +#include <arch/acpigen.h> +#include <console/console.h> +#include <device/i2c.h> +#include <device/device.h> +#include <device/path.h> +#include <gpio.h> +#include <stdint.h> +#include <string.h> +#include "chip.h" + +#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES) +static void i2c_generic_fill_ssdt(struct device *dev) +{ + struct drivers_i2c_generic_config *config = dev->chip_info; + const char *scope = acpi_device_scope(dev); + struct acpi_i2c i2c = { + .address = dev->path.i2c.device, + .mode_10bit = dev->path.i2c.mode_10bit, + .speed = config->bus_speed ? : I2C_SPEED_FAST, + .resource = scope, + }; + + if (!dev->enabled || !scope) + return; + + if (!config->hid) { + printk(BIOS_ERR, "%s: ERROR: HID required\n", dev_path(dev)); + return; + } + + /* Device */ + acpigen_write_scope(scope); + acpigen_write_device(acpi_device_name(dev)); + acpigen_write_name_string("_HID", config->hid); + acpigen_write_name_integer("_UID", config->uid); + acpigen_write_name_string("_DDN", config->desc); + acpigen_write_STA(ACPI_STATUS_DEVICE_ALL_ON); + + /* Resources */ + acpigen_write_name("_CRS"); + acpigen_write_resourcetemplate_header(); + acpi_device_write_i2c(&i2c); + acpi_device_write_interrupt(&config->irq); + acpigen_write_resourcetemplate_footer(); + + /* Wake capabilities */ + if (config->wake) { + acpigen_write_name_integer("_S0W", 4); + acpigen_write_PRW(config->wake, 3); + } + + acpigen_pop_len(); /* Device */ + acpigen_pop_len(); /* Scope */ + + printk(BIOS_INFO, "%s: %s at %s\n", acpi_device_path(dev), + config->desc ? : dev->chip_ops->name, dev_path(dev)); +} + +/* Use name specified in config or build one from I2C address */ +static const char *i2c_generic_acpi_name(struct device *dev) +{ + struct drivers_i2c_generic_config *config = dev->chip_info; + static char name[5]; + + if (config->name) + return name; + + snprintf(name, sizeof(name), "D%03.3X", dev->path.i2c.device); + name[4] = '\0'; + return name; +} +#endif + +static struct device_operations i2c_generic_ops = { + .read_resources = DEVICE_NOOP, + .set_resources = DEVICE_NOOP, + .enable_resources = DEVICE_NOOP, +#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES) + .acpi_name = &i2c_generic_acpi_name, + .acpi_fill_ssdt_generator = &i2c_generic_fill_ssdt, +#endif +}; + +static void i2c_generic_enable(struct device *dev) +{ + struct drivers_i2c_generic_config *config = dev->chip_info; + + /* Check if device is present by reading GPIO */ + if (config->device_present_gpio) { + int present = gpio_get(config->device_present_gpio); + present ^= config->device_present_gpio_invert; + + printk(BIOS_INFO, "%s is %spresent\n", + dev->chip_ops->name, present ? "" : "not "); + + if (!present) { + dev->enabled = 0; + return; + } + } + + dev->ops = &i2c_generic_ops; +} + +struct chip_operations drivers_i2c_generic_ops = { + CHIP_NAME("I2C Device") + .enable_dev = &i2c_generic_enable +}; |