Hi Simon,
-----"Simon Glass" <s...@chromium.org> schrieb: -----
> Betreff: [PATCH v2 11/35] acpi: Support generation of I2C descriptor
>
> Add a function to write a GPIO descriptor to the generated ACPI code.
>
> Signed-off-by: Simon Glass <s...@chromium.org>
> ---
>
> Changes in v2:
> - Fix memset of I2C descriptor
>
> Changes in v1: None
>
> drivers/i2c/sandbox_i2c.c | 11 ++++
> drivers/rtc/sandbox_rtc.c | 13 +++++
> include/acpi/acpi_device.h | 36 +++++++++++++
> lib/acpi/acpi_device.c | 103 +++++++++++++++++++++++++++++++++++++
> test/dm/acpigen.c | 32 ++++++++++++
> 5 files changed, 195 insertions(+)
>
> diff --git a/drivers/i2c/sandbox_i2c.c b/drivers/i2c/sandbox_i2c.c
> index f4ae2397a0..125026da90 100644
> --- a/drivers/i2c/sandbox_i2c.c
> +++ b/drivers/i2c/sandbox_i2c.c
> @@ -11,6 +11,7 @@
> #include <i2c.h>
> #include <log.h>
> #include <asm/test.h>
> +#include <dm/acpi.h>
> #include <dm/lists.h>
> #include <dm/device-internal.h>
>
> @@ -83,6 +84,15 @@ static int sandbox_i2c_xfer(struct udevice *bus, struct
> i2c_msg *msg,
> return ops->xfer(emul, msg, nmsgs);
> }
>
> +static int sandbox_i2c_get_name(const struct udevice *dev, char *out_name)
> +{
> + return acpi_copy_name(out_name, "SI2C");
> +}
> +
> +struct acpi_ops sandbox_i2c_acpi_ops = {
> + .get_name = sandbox_i2c_get_name,
> +};
> +
> static const struct dm_i2c_ops sandbox_i2c_ops = {
> .xfer = sandbox_i2c_xfer,
> };
> @@ -98,4 +108,5 @@ U_BOOT_DRIVER(i2c_sandbox) = {
> .of_match = sandbox_i2c_ids,
> .ops = &sandbox_i2c_ops,
> .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv),
> + ACPI_OPS_PTR(&sandbox_i2c_acpi_ops)
> };
> diff --git a/drivers/rtc/sandbox_rtc.c b/drivers/rtc/sandbox_rtc.c
> index b08d758a74..f2906c3397 100644
> --- a/drivers/rtc/sandbox_rtc.c
> +++ b/drivers/rtc/sandbox_rtc.c
> @@ -9,6 +9,7 @@
> #include <i2c.h>
> #include <rtc.h>
> #include <asm/rtc.h>
> +#include <dm/acpi.h>
>
> #define REG_COUNT 0x80
>
> @@ -84,6 +85,17 @@ static int sandbox_rtc_write8(struct udevice *dev,
> unsigned int reg, int val)
> return dm_i2c_reg_write(dev, reg, val);
> }
>
> +#if CONFIG_IS_ENABLED(ACPIGEN)
> +static int sandbox_rtc_get_name(const struct udevice *dev, char *out_name)
> +{
> + return acpi_copy_name(out_name, "RTCC");
> +}
> +
> +struct acpi_ops sandbox_rtc_acpi_ops = {
> + .get_name = sandbox_rtc_get_name,
> +};
> +#endif
> +
> static const struct rtc_ops sandbox_rtc_ops = {
> .get = sandbox_rtc_get,
> .set = sandbox_rtc_set,
> @@ -102,4 +114,5 @@ U_BOOT_DRIVER(rtc_sandbox) = {
> .id = UCLASS_RTC,
> .of_match = sandbox_rtc_ids,
> .ops = &sandbox_rtc_ops,
> + ACPI_OPS_PTR(&sandbox_rtc_acpi_ops)
> };
> diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
> index 70c151d150..cf1ac695a7 100644
> --- a/include/acpi/acpi_device.h
> +++ b/include/acpi/acpi_device.h
> @@ -9,6 +9,7 @@
> #ifndef __ACPI_DEVICE_H
> #define __ACPI_DEVICE_H
>
> +#include <i2c.h>
> #include <linux/bitops.h>
>
> struct acpi_ctx;
> @@ -183,6 +184,29 @@ struct acpi_gpio {
> enum acpi_gpio_polarity polarity;
> };
>
> +/* ACPI Descriptors for Serial Bus interfaces */
> +#define ACPI_SERIAL_BUS_TYPE_I2C 1
> +#define ACPI_SERIAL_BUS_TYPE_SPI 2
> +#define ACPI_I2C_SERIAL_BUS_REVISION_ID 1 /* TODO: upgrade to 2
> */
> +#define ACPI_I2C_TYPE_SPECIFIC_REVISION_ID 1
> +#define ACPI_SPI_SERIAL_BUS_REVISION_ID 1
> +#define ACPI_SPI_TYPE_SPECIFIC_REVISION_ID 1
> +
> +/**
> + * struct acpi_i2c - representation of an ACPI I2C device
> + *
> + * @address: 7-bit or 10-bit I2C address
> + * @mode_10bit: Which address size is used
> + * @speed: Bus speed in Hz
> + * @resource: Resource name for the I2C controller
> + */
> +struct acpi_i2c {
> + u16 address;
> + enum i2c_address_mode mode_10bit;
> + enum i2c_speed_rate speed;
> + const char *resource;
> +};
> +
> /**
> * acpi_device_path() - Get the full path to an ACPI device
> *
> @@ -270,4 +294,16 @@ int acpi_device_write_gpio_desc(struct acpi_ctx *ctx,
> int acpi_device_write_interrupt_or_gpio(struct acpi_ctx *ctx,
> struct udevice *dev, const char *prop);
>
> +/**
> + * acpi_device_write_i2c_dev() - Write an I2C device to ACPI
> + *
> + * This creates a I2cSerialBus descriptor for an I2C device, including
> + * information ACPI needs to use it.
> + *
> + * @ctx: ACPI context pointer
> + * @dev: I2C device to write
> + * @return 0 if OK, -ve on error
> + */
> +int acpi_device_write_i2c_dev(struct acpi_ctx *ctx, const struct udevice
> *dev);
> +
> #endif
> diff --git a/lib/acpi/acpi_device.c b/lib/acpi/acpi_device.c
> index 423b91cfd2..0136a0bdc9 100644
> --- a/lib/acpi/acpi_device.c
> +++ b/lib/acpi/acpi_device.c
> @@ -381,3 +381,106 @@ int acpi_device_write_interrupt_or_gpio(struct acpi_ctx
> *ctx,
>
> return 0;
> }
> +
> +/* 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 = acpi_device_write_zero_len(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 = acpi_device_write_zero_len(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 */
> + acpi_device_fill_len(ctx, type_length);
> +
> + /* Byte 18+: ResourceSource */
> + acpigen_emit_string(ctx, i2c->resource);
> +
> + /* Fill in I2C Descriptor Length */
> + acpi_device_fill_len(ctx, desc_length);
> +}
> +
> +/**
> + * acpi_device_set_i2c() - Set up an ACPI I2C struct from a device
> + *
> + * @dev: I2C device to convert
> + * @i2c: Place to put the new structure
> + * @scope: Scope of the I2C device (this is the controller path)
>From the declaration I would assume that "scope" is internally copied, but in
the code it is only referenced.
I would propose to add something like the following to its description:
"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."
> + * @return 0 (always)
dev_get_parent_platdata() could return NULL. Should we check this and return
and error?
> + */
> +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));
Nit: memset(i2c, 0, sizeof(*i2c));
This is only a style question. But it seems 0 is used for memset in existing
U-Boot code much more often then '\0' (~120 grep results vs ~1100 grep results).
> + 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", 100000);
Nit: I2C_SPEED_STANDARD_RATE instead of 100000?
> + i2c->resource = scope;
> +
> + return 0;
> +}
> +
> +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)
> + return log_msg_ret("set", ret);
> + acpi_device_write_i2c(ctx, &i2c);
> +
> + return 0;
> +}
> diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
> index 6aefa6845d..de9996ab35 100644
> --- a/test/dm/acpigen.c
> +++ b/test/dm/acpigen.c
> @@ -266,3 +266,35 @@ static int dm_test_acpi_interrupt_or_gpio(struct
> unit_test_state *uts)
> }
> DM_TEST(dm_test_acpi_interrupt_or_gpio,
> DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
> +
> +/* Test emitting an I2C descriptor */
> +static int dm_test_acpi_i2c(struct unit_test_state *uts)
> +{
> + struct acpi_ctx *ctx;
> + struct udevice *dev;
> + u8 *ptr;
> +
> + ut_assertok(alloc_context(&ctx));
> +
> + ptr = acpigen_get_current(ctx);
> +
> + ut_assertok(uclass_get_device(UCLASS_RTC, 0, &dev));
> + ut_assertok(acpi_device_write_i2c_dev(ctx, dev));
> + ut_asserteq(28, acpigen_get_current(ctx) - ptr);
> + ut_asserteq(ACPI_DESCRIPTOR_SERIAL_BUS, ptr[0]);
> + ut_asserteq(25, get_unaligned((u16 *)(ptr + 1)));
> + ut_asserteq(ACPI_I2C_SERIAL_BUS_REVISION_ID, ptr[3]);
> + ut_asserteq(0, ptr[4]);
> + ut_asserteq(ACPI_SERIAL_BUS_TYPE_I2C, ptr[5]);
> + ut_asserteq(0, get_unaligned((u16 *)(ptr + 7)));
> + ut_asserteq(ACPI_I2C_TYPE_SPECIFIC_REVISION_ID, ptr[9]);
> + ut_asserteq(6, get_unaligned((u16 *)(ptr + 10)));
> + ut_asserteq(100000, get_unaligned((u32 *)(ptr + 12)));
> + ut_asserteq(0x43, get_unaligned((u16 *)(ptr + 16)));
> + ut_asserteq_str("\\_SB.SI2C", (char *)ptr + 18);
> +
> + free_context(&ctx);
> +
> + return 0;
> +}
> +DM_TEST(dm_test_acpi_i2c, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
> --
> 2.26.2.645.ge9eca65c58-goog
The remarks above are just this: remarks. I would also be fine with merging
the code as it is:
Reviewed-by: Wolfgang Wallner <wolfgang.wall...@br-automation.com>
