[v2,08/12] drm/i915/spi: add spi device for discrete graphics

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index c8c8b31da4fb..fe4882e19f70 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -234,6 +234,10 @@  i915-y += \
 i915-y += \
 	gt/intel_gsc.o
 
+# graphics spi device (DGFX) support
+i915-y += \
+	spi/intel_spi.o
+
 # graphics hardware monitoring (HWMON) support
 i915-$(CONFIG_HWMON) += \
 	i915_hwmon.o
diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index 161b21eff694..49916a586dac 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -81,6 +81,8 @@ 
 #include "soc/intel_dram.h"
 #include "soc/intel_gmch.h"
 
+#include "spi/intel_spi.h"
+
 #include "i915_debugfs.h"
 #include "i915_driver.h"
 #include "i915_drm_client.h"
@@ -619,6 +621,8 @@  static void i915_driver_register(struct drm_i915_private *dev_priv)
 	/* Depends on sysfs having been initialized */
 	i915_perf_register(dev_priv);
 
+	intel_spi_init(dev_priv);
+
 	for_each_gt(gt, dev_priv, i)
 		intel_gt_driver_register(gt);
 
@@ -662,6 +666,8 @@  static void i915_driver_unregister(struct drm_i915_private *dev_priv)
 
 	i915_hwmon_unregister(dev_priv);
 
+	intel_spi_fini(dev_priv);
+
 	i915_perf_unregister(dev_priv);
 	i915_pmu_unregister(dev_priv);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ee0d7d5f135d..3d4144d600ce 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -34,6 +34,8 @@ 
 
 #include <linux/pm_qos.h>
 
+#include <linux/intel_dg_spi_aux.h>
+
 #include <drm/ttm/ttm_device.h>
 
 #include "display/intel_display_limits.h"
@@ -314,6 +316,8 @@  struct drm_i915_private {
 
 	struct i915_perf perf;
 
+	struct intel_dg_spi_dev spi;
+
 	struct i915_hwmon *hwmon;
 
 	struct intel_gt *gt[I915_MAX_GT];
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index e22a82a5ddd7..fe7a296eb84b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -323,6 +323,7 @@ 
 #define DG2_GSC_HECI2_BASE	0x00374000
 #define MTL_GSC_HECI1_BASE	0x00116000
 #define MTL_GSC_HECI2_BASE	0x00117000
+#define GEN12_GUNIT_SPI_BASE	0x00102040
 
 #define HECI_H_CSR(base)	_MMIO((base) + 0x4)
 #define   HECI_H_CSR_IE		REG_BIT(0)
diff --git a/drivers/gpu/drm/i915/spi/intel_spi.c b/drivers/gpu/drm/i915/spi/intel_spi.c
new file mode 100644
index 000000000000..17e4c7861ef5
--- /dev/null
+++ b/drivers/gpu/drm/i915/spi/intel_spi.c
@@ -0,0 +1,64 @@ 
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright(c) 2019-2024, Intel Corporation. All rights reserved.
+ */
+
+#include <linux/intel_dg_spi_aux.h>
+#include <linux/irq.h>
+#include "i915_reg.h"
+#include "i915_drv.h"
+#include "spi/intel_spi.h"
+
+#define GEN12_GUNIT_SPI_SIZE 0x80
+
+static void i915_spi_release_dev(struct device *dev)
+{
+}
+
+void intel_spi_init(struct drm_i915_private *dev_priv)
+{
+	struct intel_dg_spi_dev *spi = &dev_priv->spi;
+	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
+	struct auxiliary_device *aux_dev = &spi->aux_dev;
+	int ret;
+
+	/* Only the DGFX devices have internal SPI */
+	if (!IS_DGFX(dev_priv))
+		return;
+
+	spi->bar.parent = &pdev->resource[0];
+	spi->bar.start = GEN12_GUNIT_SPI_BASE + pdev->resource[0].start;
+	spi->bar.end = spi->bar.start + GEN12_GUNIT_SPI_SIZE - 1;
+	spi->bar.flags = IORESOURCE_MEM;
+	spi->bar.desc = IORES_DESC_NONE;
+
+	aux_dev->name = "spi";
+	aux_dev->id = (pci_domain_nr(pdev->bus) << 16) |
+		       PCI_DEVID(pdev->bus->number, pdev->devfn);
+	aux_dev->dev.parent = &pdev->dev;
+	aux_dev->dev.release = i915_spi_release_dev;
+
+	ret = auxiliary_device_init(aux_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "i915-spi aux init failed %d\n", ret);
+		return;
+	}
+
+	ret = auxiliary_device_add(aux_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "i915-spi aux add failed %d\n", ret);
+		auxiliary_device_uninit(aux_dev);
+		return;
+	}
+}
+
+void intel_spi_fini(struct drm_i915_private *dev_priv)
+{
+	struct intel_dg_spi_dev *spi = &dev_priv->spi;
+	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
+
+	dev_dbg(&pdev->dev, "removing i915-spi cell\n");
+
+	auxiliary_device_delete(&spi->aux_dev);
+	auxiliary_device_uninit(&spi->aux_dev);
+}
diff --git a/drivers/gpu/drm/i915/spi/intel_spi.h b/drivers/gpu/drm/i915/spi/intel_spi.h
new file mode 100644
index 000000000000..ed4153401f5d
--- /dev/null
+++ b/drivers/gpu/drm/i915/spi/intel_spi.h
@@ -0,0 +1,15 @@ 
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright(c) 2019-2024 Intel Corporation. All rights reserved.
+ */
+
+#ifndef __INTEL_SPI_H__
+#define __INTEL_SPI_H__
+
+struct drm_i915_private;
+
+void intel_spi_init(struct drm_i915_private *i915);
+
+void intel_spi_fini(struct drm_i915_private *i915);
+
+#endif /* __INTEL_SPI_H__ */