[PATCH v3 12/35] acpi: Support generation of SPI descriptor

Bin Meng bmeng.cn at gmail.com
Mon Jun 29 03:27:44 CEST 2020


Hi Simon,

On Sun, Jun 14, 2020 at 10:55 AM Simon Glass <sjg at chromium.org> wrote:
>
> Add a function to write a SPI descriptor to the generated ACPI code.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> Changes in v3:
> - Make acpi_device_write_spi() static
> - Add an extra comment about scope to acpi_device_set_spi()
> - Use BIT() in a few places
> - Resist the temptation to go to >80 characters
>
> Changes in v2:
> - Fix memset of SPI descriptor
>
>  drivers/spi/sandbox_spi.c  |  11 ++++
>  include/acpi/acpi_device.h |  36 +++++++++++
>  include/spi.h              |   4 +-
>  lib/acpi/acpi_device.c     | 124 +++++++++++++++++++++++++++++++++++++
>  test/dm/acpigen.c          |  36 +++++++++++
>  5 files changed, 209 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/sandbox_spi.c b/drivers/spi/sandbox_spi.c
> index b0a46c8868..4264acc953 100644
> --- a/drivers/spi/sandbox_spi.c
> +++ b/drivers/spi/sandbox_spi.c
> @@ -21,6 +21,7 @@
>  #include <linux/errno.h>
>  #include <asm/spi.h>
>  #include <asm/state.h>
> +#include <dm/acpi.h>
>  #include <dm/device-internal.h>
>
>  #ifndef CONFIG_SPI_IDLE_VAL
> @@ -133,6 +134,15 @@ static int sandbox_spi_get_mmap(struct udevice *dev, ulong *map_basep,
>         return 0;
>  }
>
> +static int sandbox_spi_get_name(const struct udevice *dev, char *out_name)
> +{
> +       return acpi_copy_name(out_name, "SSPI");
> +}
> +
> +struct acpi_ops sandbox_spi_acpi_ops = {
> +       .get_name       = sandbox_spi_get_name,
> +};
> +
>  static const struct dm_spi_ops sandbox_spi_ops = {
>         .xfer           = sandbox_spi_xfer,
>         .set_speed      = sandbox_spi_set_speed,
> @@ -151,4 +161,5 @@ U_BOOT_DRIVER(spi_sandbox) = {
>         .id     = UCLASS_SPI,
>         .of_match = sandbox_spi_ids,
>         .ops    = &sandbox_spi_ops,
> +       ACPI_OPS_PTR(&sandbox_spi_acpi_ops)
>  };
> diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
> index f738b03d58..c0c96183e4 100644
> --- a/include/acpi/acpi_device.h
> +++ b/include/acpi/acpi_device.h
> @@ -10,6 +10,7 @@
>  #define __ACPI_DEVICE_H
>
>  #include <i2c.h>
> +#include <spi.h>
>  #include <linux/bitops.h>
>
>  struct acpi_ctx;
> @@ -207,6 +208,29 @@ struct acpi_i2c {
>         const char *resource;
>  };
>
> +/**
> + * struct acpi_spi - representation of an ACPI SPI device
> + *
> + * @device_select: Chip select used by this device (typically 0)
> + * @device_select_polarity: Polarity for the device
> + * @wire_mode: Number of wires used for SPI
> + * @speed: Bus speed in Hz
> + * @data_bit_length: Word length for SPI (typically 8)
> + * @clock_phase: Clock phase to capture data
> + * @clock_polarity: Bus polarity
> + * @resource: Resource name for the SPI controller
> + */
> +struct acpi_spi {
> +       u16 device_select;
> +       enum spi_polarity device_select_polarity;
> +       enum spi_wire_mode wire_mode;
> +       unsigned int speed;
> +       u8 data_bit_length;
> +       enum spi_clock_phase clock_phase;
> +       enum spi_polarity clock_polarity;
> +       const char *resource;
> +};
> +
>  /**
>   * acpi_device_path() - Get the full path to an ACPI device
>   *
> @@ -306,4 +330,16 @@ int acpi_device_write_interrupt_or_gpio(struct acpi_ctx *ctx,
>   */
>  int acpi_device_write_i2c_dev(struct acpi_ctx *ctx, const struct udevice *dev);
>
> +/**
> + * acpi_device_write_spi_dev() - Write a SPI device to ACPI
> + *
> + * This writes a serial bus descriptor for the SPI device so that ACPI can use
> + * it
> + *
> + * @ctx: ACPI context pointer
> + * @dev: SPI device to write
> + * @return 0 if OK, -ve on error
> + */
> +int acpi_device_write_spi_dev(struct acpi_ctx *ctx, const struct udevice *dev);
> +
>  #endif
> diff --git a/include/spi.h b/include/spi.h
> index 5cc6d6e008..f34533f54e 100644
> --- a/include/spi.h
> +++ b/include/spi.h
> @@ -13,8 +13,8 @@
>  #include <linux/bitops.h>
>
>  /* SPI mode flags */
> -#define SPI_CPHA       BIT(0)                  /* clock phase */
> -#define SPI_CPOL       BIT(1)                  /* clock polarity */
> +#define SPI_CPHA       BIT(0)  /* clock phase (1 = SPI_CLOCK_PHASE_SECOND) */
> +#define SPI_CPOL       BIT(1)  /* clock polarity (1 = SPI_POLARITY_HIGH) */
>  #define SPI_MODE_0     (0|0)                   /* (original MicroWire) */
>  #define SPI_MODE_1     (0|SPI_CPHA)
>  #define SPI_MODE_2     (SPI_CPOL|0)
> diff --git a/lib/acpi/acpi_device.c b/lib/acpi/acpi_device.c
> index 40d1a82d27..38101c8b96 100644
> --- a/lib/acpi/acpi_device.c
> +++ b/lib/acpi/acpi_device.c
> @@ -488,3 +488,127 @@ int acpi_device_write_i2c_dev(struct acpi_ctx *ctx, const struct udevice *dev)
>
>         return 0;
>  }
> +
> +#ifdef CONFIG_SPI

Why #ifdef? Other APIs don't have this

> +/* ACPI 6.1 section 6.4.3.8.2.2 - SpiSerialBus() */
> +static void acpi_device_write_spi(struct acpi_ctx *ctx, const struct acpi_spi *spi)
> +{
> +       void *desc_length, *type_length;
> +       u16 flags = 0;
> +
> +       /* 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_SPI_SERIAL_BUS_REVISION_ID);
> +
> +       /* Byte 4: Resource Source Index is Reserved */
> +       acpigen_emit_byte(ctx, 0);
> +
> +       /* Byte 5: Serial Bus Type is SPI */
> +       acpigen_emit_byte(ctx, ACPI_SERIAL_BUS_TYPE_SPI);
> +
> +       /*
> +        * Byte 6: Flags
> +        *  [7:2]: 0 => Reserved
> +        *    [1]: 1 => ResourceConsumer
> +        *    [0]: 0 => ControllerInitiated
> +        */
> +       acpigen_emit_byte(ctx, BIT(1));
> +
> +       /*
> +        * Byte 7-8: Type Specific Flags
> +        *   [15:2]: 0 => Reserveda
> +        *      [1]: 0 => ActiveLow, 1 => ActiveHigh
> +        *      [0]: 0 => FourWire, 1 => ThreeWire
> +        */
> +       if (spi->wire_mode == SPI_3_WIRE_MODE)
> +               flags |= BIT(0);
> +       if (spi->device_select_polarity == SPI_POLARITY_HIGH)
> +               flags |= BIT(1);
> +       acpigen_emit_word(ctx, flags);
> +
> +       /* Byte 9: Type Specific Revision ID */
> +       acpigen_emit_byte(ctx, ACPI_SPI_TYPE_SPECIFIC_REVISION_ID);
> +
> +       /* Byte 10-11: SPI Type Data Length */
> +       type_length = acpi_device_write_zero_len(ctx);
> +
> +       /* Byte 12-15: Connection Speed */
> +       acpigen_emit_dword(ctx, spi->speed);
> +
> +       /* Byte 16: Data Bit Length */
> +       acpigen_emit_byte(ctx, spi->data_bit_length);
> +
> +       /* Byte 17: Clock Phase */
> +       acpigen_emit_byte(ctx, spi->clock_phase);
> +
> +       /* Byte 18: Clock Polarity */
> +       acpigen_emit_byte(ctx, spi->clock_polarity);
> +
> +       /* Byte 19-20: Device Selection */
> +       acpigen_emit_word(ctx, spi->device_select);
> +
> +       /* Fill in Type Data Length */
> +       acpi_device_fill_len(ctx, type_length);
> +
> +       /* Byte 21+: ResourceSource String */
> +       acpigen_emit_string(ctx, spi->resource);
> +
> +       /* Fill in SPI Descriptor Length */
> +       acpi_device_fill_len(ctx, desc_length);
> +}
> +
> +/**
> + * acpi_device_set_spi() - Set up an ACPI SPI 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 @spi.
> + *
> + * @dev: SPI device to convert
> + * @spi: Place to put the new structure
> + * @scope: Scope of the SPI device (this is the controller path)
> + * @return 0 (always)
> + */
> +static int acpi_device_set_spi(const struct udevice *dev, struct acpi_spi *spi,
> +                              const char *scope)
> +{
> +       struct dm_spi_slave_platdata *plat;
> +       struct spi_slave *slave = dev_get_parent_priv(dev);
> +
> +       plat = dev_get_parent_platdata(slave->dev);
> +       memset(spi, '\0', sizeof(*spi));
> +       spi->device_select = plat->cs;
> +       spi->device_select_polarity = SPI_POLARITY_LOW;
> +       spi->wire_mode = SPI_4_WIRE_MODE;
> +       spi->speed = plat->max_hz;
> +       spi->data_bit_length = slave->wordlen;
> +       spi->clock_phase = plat->mode & SPI_CPHA ?
> +                SPI_CLOCK_PHASE_SECOND : SPI_CLOCK_PHASE_FIRST;
> +       spi->clock_polarity = plat->mode & SPI_CPOL ?
> +                SPI_POLARITY_HIGH : SPI_POLARITY_LOW;
> +       spi->resource = scope;
> +
> +       return 0;
> +}
> +
> +int acpi_device_write_spi_dev(struct acpi_ctx *ctx, const struct udevice *dev)
> +{
> +       char scope[ACPI_PATH_MAX];
> +       struct acpi_spi spi;
> +       int ret;
> +
> +       ret = acpi_device_scope(dev, scope, sizeof(scope));
> +       if (ret)
> +               return log_msg_ret("scope", ret);
> +       ret = acpi_device_set_spi(dev, &spi, scope);
> +       if (ret)
> +               return log_msg_ret("set", ret);
> +       acpi_device_write_spi(ctx, &spi);
> +
> +       return 0;
> +}
> +#endif /* CONFIG_SPI */
> diff --git a/test/dm/acpigen.c b/test/dm/acpigen.c
> index 53842be55a..571510722d 100644
> --- a/test/dm/acpigen.c
> +++ b/test/dm/acpigen.c
> @@ -302,3 +302,39 @@ static int dm_test_acpi_i2c(struct unit_test_state *uts)
>         return 0;
>  }
>  DM_TEST(dm_test_acpi_i2c, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
> +
> +/* Test emitting a SPI descriptor */
> +static int dm_test_acpi_spi(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_first_device_err(UCLASS_SPI_FLASH, &dev));
> +       ut_assertok(acpi_device_write_spi_dev(ctx, dev));
> +       ut_asserteq(31, acpigen_get_current(ctx) - ptr);
> +       ut_asserteq(ACPI_DESCRIPTOR_SERIAL_BUS, ptr[0]);
> +       ut_asserteq(28, get_unaligned((u16 *)(ptr + 1)));
> +       ut_asserteq(ACPI_SPI_SERIAL_BUS_REVISION_ID, ptr[3]);
> +       ut_asserteq(0, ptr[4]);
> +       ut_asserteq(ACPI_SERIAL_BUS_TYPE_SPI, ptr[5]);
> +       ut_asserteq(2, ptr[6]);
> +       ut_asserteq(0, get_unaligned((u16 *)(ptr + 7)));
> +       ut_asserteq(ACPI_SPI_TYPE_SPECIFIC_REVISION_ID, ptr[9]);
> +       ut_asserteq(9, get_unaligned((u16 *)(ptr + 10)));
> +       ut_asserteq(40000000, get_unaligned((u32 *)(ptr + 12)));
> +       ut_asserteq(8, ptr[16]);
> +       ut_asserteq(0, ptr[17]);
> +       ut_asserteq(0, ptr[18]);
> +       ut_asserteq(0, get_unaligned((u16 *)(ptr + 19)));
> +       ut_asserteq_str("\\_SB.SSPI", (char *)ptr + 21);
> +
> +       free_context(&ctx);
> +
> +       return 0;
> +}
> +DM_TEST(dm_test_acpi_spi, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
> --

Other than above,
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>

Regards,
Bin


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