[PATCH v4 12/35] acpi: Support generation of SPI descriptor
Simon Glass
sjg at chromium.org
Tue Jul 7 21:11:49 CEST 2020
Add a function to write a SPI descriptor to the generated ACPI code.
Signed-off-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
---
Changes in v4:
- Move SPI macros to next patch
- Rename the length-writing functions to indicate they are for large resources
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 | 39 ++++++++++++
include/spi.h | 4 +-
lib/acpi/acpi_device.c | 124 +++++++++++++++++++++++++++++++++++++
test/dm/acpigen.c | 36 +++++++++++
5 files changed, 212 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/sandbox_spi.c b/drivers/spi/sandbox_spi.c
index 570ae285f2..77797bf096 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(sandbox_spi) = {
.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 9ba395771e..848ccb9434 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;
@@ -186,8 +187,11 @@ struct acpi_gpio {
/* 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
@@ -204,6 +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
*
@@ -303,4 +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 7fca646759..fd931d221a 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 c0d5a9acae..b628fa1337 100644
--- a/lib/acpi/acpi_device.c
+++ b/lib/acpi/acpi_device.c
@@ -492,3 +492,127 @@ int acpi_device_write_i2c_dev(struct acpi_ctx *ctx, const struct udevice *dev)
return ret;
}
+
+#ifdef CONFIG_SPI
+/* 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 = largeres_write_len_f(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 = largeres_write_len_f(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 */
+ largeres_fill_len(ctx, type_length);
+
+ /* Byte 21+: ResourceSource String */
+ acpigen_emit_string(ctx, spi->resource);
+
+ /* Fill in SPI Descriptor Length */
+ largeres_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 c210ceb404..f3d9915500 100644
--- a/test/dm/acpigen.c
+++ b/test/dm/acpigen.c
@@ -308,3 +308,39 @@ 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.SPI0", (char *)ptr + 21);
+
+ free_context(&ctx);
+
+ return 0;
+}
+DM_TEST(dm_test_acpi_spi, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
--
2.27.0.383.g050319c2ae-goog
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