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acpi: Support generation of I2C descriptor

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Add a function to write a GPIO descriptor to the generated ACPI code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass
2020-07-07 13:11:48 -06:00
committed by Bin Meng
parent 4ebc940b39
commit 31e1787ec1
5 changed files with 196 additions and 0 deletions
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107
lib/acpi/acpi_device.c
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@@ -385,3 +385,110 @@ int acpi_device_write_interrupt_or_gpio(struct acpi_ctx *ctx,
return pin;
}
/* ACPI 6.3 section 6.4.3.8.2.1 - I2cSerialBus() */
static void acpi_device_write_i2c(struct acpi_ctx *ctx,
const struct acpi_i2c *i2c)
{
void *desc_length, *type_length;
/* Byte 0: Descriptor Type */
acpigen_emit_byte(ctx, ACPI_DESCRIPTOR_SERIAL_BUS);
/* Byte 1+2: Length (filled in later) */
desc_length = largeres_write_len_f(ctx);
/* Byte 3: Revision ID */
acpigen_emit_byte(ctx, ACPI_I2C_SERIAL_BUS_REVISION_ID);
/* Byte 4: Resource Source Index is Reserved */
acpigen_emit_byte(ctx, 0);
/* Byte 5: Serial Bus Type is I2C */
acpigen_emit_byte(ctx, ACPI_SERIAL_BUS_TYPE_I2C);
/*
* Byte 6: Flags
* [7:2]: 0 => Reserved
* [1]: 1 => ResourceConsumer
* [0]: 0 => ControllerInitiated
*/
acpigen_emit_byte(ctx, 1 << 1);
/*
* Byte 7-8: Type Specific Flags
* [15:1]: 0 => Reserved
* [0]: 0 => 7bit, 1 => 10bit
*/
acpigen_emit_word(ctx, i2c->mode_10bit);
/* Byte 9: Type Specific Revision ID */
acpigen_emit_byte(ctx, ACPI_I2C_TYPE_SPECIFIC_REVISION_ID);
/* Byte 10-11: I2C Type Data Length */
type_length = largeres_write_len_f(ctx);
/* Byte 12-15: I2C Bus Speed */
acpigen_emit_dword(ctx, i2c->speed);
/* Byte 16-17: I2C Slave Address */
acpigen_emit_word(ctx, i2c->address);
/* Fill in Type Data Length */
largeres_fill_len(ctx, type_length);
/* Byte 18+: ResourceSource */
acpigen_emit_string(ctx, i2c->resource);
/* Fill in I2C Descriptor Length */
largeres_fill_len(ctx, desc_length);
}
/**
* acpi_device_set_i2c() - Set up an ACPI I2C struct from a device
*
* The value of @scope is not copied, but only referenced. This implies the
* caller has to ensure it stays valid for the lifetime of @i2c.
*
* @dev: I2C device to convert
* @i2c: Place to put the new structure
* @scope: Scope of the I2C device (this is the controller path)
* @return chip address of device
*/
static int acpi_device_set_i2c(const struct udevice *dev, struct acpi_i2c *i2c,
const char *scope)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
struct udevice *bus = dev_get_parent(dev);
memset(i2c, '\0', sizeof(*i2c));
i2c->address = chip->chip_addr;
i2c->mode_10bit = 0;
/*
* i2c_bus->speed_hz is set if this device is probed, but if not we
* must use the device tree
*/
i2c->speed = dev_read_u32_default(bus, "clock-frequency",
I2C_SPEED_STANDARD_RATE);
i2c->resource = scope;
return i2c->address;
}
int acpi_device_write_i2c_dev(struct acpi_ctx *ctx, const struct udevice *dev)
{
char scope[ACPI_PATH_MAX];
struct acpi_i2c i2c;
int ret;
ret = acpi_device_scope(dev, scope, sizeof(scope));
if (ret)
return log_msg_ret("scope", ret);
ret = acpi_device_set_i2c(dev, &i2c, scope);
if (ret < 0)
return log_msg_ret("set", ret);
acpi_device_write_i2c(ctx, &i2c);
return ret;
}