Hi
+ linux-acpi
On 10/23/24 8:51 AM, Shyam Sundar S K wrote:
As of now, the I3C subsystem only has ARM-specific initialization, and
there is no corresponding ACPI plumbing present. To address this, ACPI
support needs to be added to both the I3C core and DW driver.
Add support to get the ACPI handle from the _HID probed and parse the apci
object to retrieve the slave information from BIOS.
Based on the acpi object information propogated via BIOS, build the i3c
board information so that the same information can be used across the
driver to handle the slave requests.
I think it would be good to have a DSDT example here?
Co-developed-by: Sanket Goswami <Sanket.Goswami@xxxxxxx>
Signed-off-by: Sanket Goswami <Sanket.Goswami@xxxxxxx>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
---
drivers/i3c/internals.h | 2 +
drivers/i3c/master.c | 84 ++++++++++++++++++++++++++++++
drivers/i3c/master/dw-i3c-master.c | 7 +++
include/linux/i3c/master.h | 1 +
4 files changed, 94 insertions(+)
diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index 433f6088b7ce..d2d6c69b19dd 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -10,6 +10,8 @@
#include <linux/i3c/master.h>
+#define AMD_I3C_GET_SLAVE_ADDR 0x30
+
void i3c_bus_normaluse_lock(struct i3c_bus *bus);
void i3c_bus_normaluse_unlock(struct i3c_bus *bus);
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 6f3eb710a75d..7d23c32e1c0f 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2251,6 +2251,84 @@ static int of_i3c_master_add_dev(struct i3c_master_controller *master,
return ret;
}
+#if IS_ENABLED(CONFIG_ACPI)
+static int i3c_acpi_configure_master(struct i3c_master_controller *master)
+{
+ struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+ enum i3c_addr_slot_status addrstatus;
+ struct i3c_dev_boardinfo *boardinfo;
+ struct device *dev = &master->dev;
+ struct fwnode_handle *fwnode;
+ struct acpi_device *adev;
+ u32 slv_addr, num_dev;
+ acpi_status status;
+ u64 val;
+
+ status = acpi_evaluate_object_typed(master->ahandle, "_DSD", NULL, &buf, ACPI_TYPE_PACKAGE);
+ if (ACPI_FAILURE(status)) {
+ dev_err(&master->dev, "Error reading _DSD:%s\n", acpi_format_exception(status));
+ return -ENODEV;
+ }
+
+ num_dev = device_get_child_node_count(dev);
+ if (!num_dev) {
+ dev_err(&master->dev, "Error: no child node present\n");
+ return -EINVAL;
+ }
+
+ device_for_each_child_node(dev, fwnode) {
+ adev = to_acpi_device_node(fwnode);
+ if (!adev)
+ return -ENODEV;
+
+ status = acpi_evaluate_integer(adev->handle, "_ADR", NULL, &val);
+ if (ACPI_FAILURE(status)) {
+ dev_err(&master->dev, "Error: eval _ADR failed\n");
+ return -EINVAL;
+ }
+ slv_addr = val >> AMD_I3C_GET_SLAVE_ADDR;
This doesn't seem to match with ACPI 6.5 spec [1] chapter 6.1.1 _ADR
(Address)? Address encoding for I3C says:
Bits [63:52] - Reserved
Bits [51:48] - Master Instance
Bits [47:0] - I3C Device Provisional ID, following encoding defined in
the MIPI
Specification for I3C.
If an I3C device supports a static address instead of a Provisional ID,
then bits
[47:7] are Reserved (zero), and bits [6:0] are the 7-bit static address.
1. https://uefi.org/sites/default/files/resources/ACPI_Spec_6_5_Aug29.pdf
+
+ boardinfo = devm_kzalloc(dev, sizeof(*boardinfo), GFP_KERNEL);
+ if (!boardinfo)
+ return -ENOMEM;
+
+ if (slv_addr) {
+ if (slv_addr > I3C_MAX_ADDR)
+ return -EINVAL;
+
+ addrstatus = i3c_bus_get_addr_slot_status(&master->bus, slv_addr);
+ if (addrstatus != I3C_ADDR_SLOT_FREE)
+ return -EINVAL;
+ }
+
+ boardinfo->static_addr = slv_addr;
+ if (boardinfo->static_addr > I3C_MAX_ADDR)
+ return -EINVAL;
+
+ addrstatus = i3c_bus_get_addr_slot_status(&master->bus, boardinfo->static_addr);
+ if (addrstatus != I3C_ADDR_SLOT_FREE)
+ return -EINVAL;
+
+ boardinfo->pid = (val & GENMASK(47, 0));
+ if ((boardinfo->pid & GENMASK_ULL(63, 48)) ||
+ I3C_PID_RND_LOWER_32BITS(boardinfo->pid))
+ return -EINVAL;
+
+ /*
+ * According to the specification, SETDASA is not supported for DIMM slaves
+ * during device discovery. Therefore, AMD BIOS will populate same initial
+ * dynamic address as the static address.
+ */
+ boardinfo->init_dyn_addr = boardinfo->static_addr;
+ list_add_tail(&boardinfo->node, &master->boardinfo.i3c);
+ }
+
+ return 0;
+}
+#else
+static int i3c_acpi_configure_master(struct i3c_master_controller *master) { return 0; }
+#endif
+
static int of_populate_i3c_bus(struct i3c_master_controller *master)
{
struct device *dev = &master->dev;
@@ -2771,6 +2849,12 @@ int i3c_master_register(struct i3c_master_controller *master,
master->dev.coherent_dma_mask = parent->coherent_dma_mask;
master->dev.dma_parms = parent->dma_parms;
+ if (has_acpi_companion(master->dev.parent)) {
+ ret = i3c_acpi_configure_master(master);
+ if (ret < 0)
+ return ret;
+ }
+
ret = of_populate_i3c_bus(master);
if (ret)
goto err_put_dev;
diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index fd58a95ae1c3..f683e2a398ad 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -1602,6 +1602,13 @@ int dw_i3c_common_probe(struct dw_i3c_master *master,
master->maxdevs = ret >> 16;
master->free_pos = GENMASK(master->maxdevs - 1, 0);
+#if IS_ENABLED(CONFIG_ACPI)
+ ACPI_COMPANION_SET(&master->base.dev, ACPI_COMPANION(&pdev->dev));
+ master->base.ahandle = acpi_device_handle(ACPI_COMPANION(&pdev->dev));
+ if (!master->base.ahandle)
+ dev_err(&pdev->dev, "Failed to get acpi device handle\n");
+#endif
+
INIT_WORK(&master->hj_work, dw_i3c_hj_work);
ret = i3c_master_register(&master->base, &pdev->dev,
&dw_mipi_i3c_ops, false);
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index 2a1ed05d5782..367faf7c4bf3 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -523,6 +523,7 @@ struct i3c_master_controller {
} boardinfo;
struct i3c_bus bus;
struct workqueue_struct *wq;
+ acpi_handle ahandle;
};
/**
