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

[Alexander Usyskin]

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

Add auxiliary driver for i915 on-die spi device.

CC: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler at intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin at 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