[PATCH 03/10] drm/i915/spi: add driver for on-die spi device

Alexander Usyskin
2023-09-10T12:44:48Z

From: Tomas Winkler <tomas.winkler@intel.com>

Add auxiliary driver for i915 on-die spi device.

CC: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
drivers/gpu/drm/i915/Kconfig | 1 +
drivers/gpu/drm/i915/Makefile | 3 +
drivers/gpu/drm/i915/spi/intel_spi_drv.c | 141 +++++++++++++++++++++++
3 files changed, 145 insertions(+)
create mode 100644 drivers/gpu/drm/i915/spi/intel_spi_drv.c

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index ce397a8797f7..c13d25658d87 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -39,6 +39,7 @@ config DRM_I915
select DRM_TTM
select DRM_BUDDY
select AUXILIARY_BUS
+ select MTD
help
Choose this option if you have a system that has "Intel Graphics
Media Accelerator" or "HD Graphics" integrated graphics,
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index f16870ad2615..544e39448c3c 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -393,6 +393,9 @@ ifdef CONFIG_DRM_I915_WERROR
cmd_checkdoc = $(srctree)/scripts/kernel-doc -none -Werror $<
endif

+obj-m += i915_spi.o
+i915_spi-y := spi/intel_spi_drv.o
+
# header test

# exclude some broken headers from the test coverage
diff --git a/drivers/gpu/drm/i915/spi/intel_spi_drv.c b/drivers/gpu/drm/i915/spi/intel_spi_drv.c
new file mode 100644
index 000000000000..15c77b4b38bb
--- /dev/null
+++ b/drivers/gpu/drm/i915/spi/intel_spi_drv.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright(c) 2019-2022, Intel Corporation. All rights reserved.
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/ioport.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include "spi/intel_spi.h"
+
+struct i915_spi {
+ struct kref refcnt;
+ void __iomem *base;
+ size_t size;
+ unsigned int nregions;
+ struct {
+ const char *name;
+ u8 id;
+ u64 offset;
+ u64 size;
+ } regions[];
+};
+
+static void i915_spi_release(struct kref *kref)
+{
+ struct i915_spi *spi = container_of(kref, struct i915_spi, refcnt);
+ int i;
+
+ pr_debug("freeing spi memory\n");
+ for (i = 0; i < spi->nregions; i++)
+ kfree(spi->regions[i].name);
+ kfree(spi);
+}
+
+static int i915_spi_probe(struct auxiliary_device *aux_dev,
+ const struct auxiliary_device_id *aux_dev_id)
+{
+ struct intel_spi *ispi = auxiliary_dev_to_intel_spi_dev(aux_dev);
+ struct device *device;
+ struct i915_spi *spi;
+ unsigned int nregions;
+ unsigned int i, n;
+ size_t size;
+ char *name;
+ size_t name_size;
+ int ret;
+
+ device = &aux_dev->dev;
+
+ /* count available regions */
+ for (nregions = 0, i = 0; i < I915_SPI_REGIONS; i++) {
+ if (ispi->regions[i].name)
+ nregions++;
+ }
+
+ if (!nregions) {
+ dev_err(device, "no regions defined\n");
+ return -ENODEV;
+ }
+
+ size = sizeof(*spi) + sizeof(spi->regions[0]) * nregions;
+ spi = kzalloc(size, GFP_KERNEL);
+ if (!spi)
+ return -ENOMEM;
+
+ kref_init(&spi->refcnt);
+
+ spi->nregions = nregions;
+ for (n = 0, i = 0; i < I915_SPI_REGIONS; i++) {
+ if (ispi->regions[i].name) {
+ name_size = strlen(dev_name(&aux_dev->dev)) +
+ strlen(ispi->regions[i].name) + 2; /* for point */
+ name = kzalloc(name_size, GFP_KERNEL);
+ if (!name)
+ continue;
+ snprintf(name, name_size, "%s.%s",
+ dev_name(&aux_dev->dev), ispi->regions[i].name);
+ spi->regions[n].name = name;
+ spi->regions[n].id = i;
+ n++;
+ }
+ }
+
+ spi->base = devm_ioremap_resource(device, &ispi->bar);
+ if (IS_ERR(spi->base)) {
+ dev_err(device, "mmio not mapped\n");
+ ret = PTR_ERR(spi->base);
+ goto err;
+ }
+
+ dev_set_drvdata(&aux_dev->dev, spi);
+
+ dev_dbg(device, "i915-spi is bound\n");
+
+ return 0;
+
+err:
+ kref_put(&spi->refcnt, i915_spi_release);
+ return ret;
+}
+
+static void i915_spi_remove(struct auxiliary_device *aux_dev)
+{
+ struct i915_spi *spi = dev_get_drvdata(&aux_dev->dev);
+
+ if (!spi)
+ return;
+
+ dev_set_drvdata(&aux_dev->dev, NULL);
+
+ kref_put(&spi->refcnt, i915_spi_release);
+}
+
+static const struct auxiliary_device_id i915_spi_id_table[] = {
+ {
+ .name = "i915.spi",
+ },
+ {
+ /* sentinel */
+ }
+};
+MODULE_DEVICE_TABLE(auxiliary, i915_spi_id_table);
+
+static struct auxiliary_driver i915_spi_driver = {
+ .probe = i915_spi_probe,
+ .remove = i915_spi_remove,
+ .driver = {
+ /* auxiliary_driver_register() sets .name to be the modname */
+ },
+ .id_table = i915_spi_id_table
+};
+
+module_auxiliary_driver(i915_spi_driver);
+
+MODULE_ALIAS("auxiliary:i915.spi");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel DGFX SPI driver");
--
2.34.1