[PATCH v4 1/2] staging: ion: Add generic ion-physmem driver

From: Andrew Andrianov
Date: Tue Jun 09 2015 - 10:59:27 EST


This patch adds a generic ion driver that allows
ion heaps to be added via devicetree. It provides
a simple and generic way to feed physical memory regions
to ion without writing a custom driver, e.g.

ion_sram: ion@0x00100000 {
compatible = "ion,physmem";
reg = <0x00100000 0x40000>;
reg-names = "memory";
ion-heap-id = <1>;
ion-heap-type = <ION_HEAP_TYPE_DMA>;
ion-heap-align = <0x10>;
ion-heap-name = "SRAM";
};

Signed-off-by: Andrew Andrianov <andrew@xxxxxxxxxx>
---
drivers/staging/android/ion/Kconfig | 7 +
drivers/staging/android/ion/Makefile | 5 +-
drivers/staging/android/ion/ion_physmem.c | 229 ++++++++++++++++++++++++++++++
include/dt-bindings/ion,physmem.h | 17 +++
4 files changed, 256 insertions(+), 2 deletions(-)
create mode 100644 drivers/staging/android/ion/ion_physmem.c
create mode 100644 include/dt-bindings/ion,physmem.h

diff --git a/drivers/staging/android/ion/Kconfig b/drivers/staging/android/ion/Kconfig
index 3452346..c558cf8 100644
--- a/drivers/staging/android/ion/Kconfig
+++ b/drivers/staging/android/ion/Kconfig
@@ -33,3 +33,10 @@ config ION_TEGRA
help
Choose this option if you wish to use ion on an nVidia Tegra.

+config ION_PHYSMEM
+ bool "Generic PhysMem ION driver"
+ depends on ION
+ help
+ Provides a generic ION driver that registers the
+ /dev/ion device with heaps from devicetree entries.
+ This heaps are made of chunks of physical memory
diff --git a/drivers/staging/android/ion/Makefile b/drivers/staging/android/ion/Makefile
index b56fd2b..ac9856d 100644
--- a/drivers/staging/android/ion/Makefile
+++ b/drivers/staging/android/ion/Makefile
@@ -5,6 +5,7 @@ ifdef CONFIG_COMPAT
obj-$(CONFIG_ION) += compat_ion.o
endif

-obj-$(CONFIG_ION_DUMMY) += ion_dummy_driver.o
-obj-$(CONFIG_ION_TEGRA) += tegra/
+obj-$(CONFIG_ION_DUMMY) += ion_dummy_driver.o
+obj-$(CONFIG_ION_PHYSMEM) += ion_physmem.o
+obj-$(CONFIG_ION_TEGRA) += tegra/

diff --git a/drivers/staging/android/ion/ion_physmem.c b/drivers/staging/android/ion/ion_physmem.c
new file mode 100644
index 0000000..ba5135f
--- /dev/null
+++ b/drivers/staging/android/ion/ion_physmem.c
@@ -0,0 +1,229 @@
+/*
+ * Copyright (C) 2015 RC Module
+ * Andrew Andrianov <andrew@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Generic devicetree physmem driver for ION Memory Manager
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include "ion.h"
+#include "ion_priv.h"
+
+#define DRVNAME "ion-physmem"
+
+static struct ion_device *idev;
+static uint32_t claimed_heap_ids;
+
+static const struct of_device_id of_match_table[] = {
+ { .compatible = "ion,physmem", },
+ { /* end of list */ }
+};
+
+struct physmem_ion_dev {
+ struct ion_platform_heap data;
+ struct ion_heap *heap;
+ int need_free_coherent;
+ void *freepage_ptr;
+ struct clk *clk;
+ uint32_t heap_id;
+};
+
+static int ion_physmem_probe(struct platform_device *pdev)
+{
+ int ret;
+ u32 ion_heap_id, ion_heap_align, ion_heap_type;
+ ion_phys_addr_t addr;
+ size_t size = 0;
+ const char *ion_heap_name = NULL;
+ struct resource *res;
+ struct physmem_ion_dev *ipdev;
+
+ /*
+ Looks like we can only have one ION device in our system.
+ Therefore we call ion_device_create on first probe and only
+ add heaps to it on subsequent probe calls.
+ FixMe:
+ 1. Do we need to hold a spinlock here?
+ 2. Can several probes race here on SMP?
+ */
+
+ if (!idev) {
+ idev = ion_device_create(NULL);
+ dev_info(&pdev->dev, "ION PhysMem Driver. (c) RC Module 2015\n");
+ if (!idev)
+ return -ENOMEM;
+ }
+
+ ipdev = kzalloc(sizeof(*ipdev), GFP_KERNEL);
+ if (!ipdev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, ipdev);
+
+ /* Read out name first for the sake of sane error-reporting */
+ ret = of_property_read_string(pdev->dev.of_node, "ion-heap-name",
+ &ion_heap_name);
+ if (ret != 0)
+ goto errfreeipdev;
+
+ ret = of_property_read_u32(pdev->dev.of_node, "ion-heap-id",
+ &ion_heap_id);
+ if (ret != 0)
+ goto errfreeipdev;
+
+ /* Check id to be sane first */
+ if ((ion_heap_id < 0) || (ion_heap_id >= ION_NUM_HEAP_IDS)) {
+ dev_err(&pdev->dev, "bad heap id specified: %d\n",
+ ion_heap_id);
+ goto errfreeipdev;
+ }
+
+ if ((1 << ion_heap_id) & claimed_heap_ids) {
+ dev_err(&pdev->dev, "heap id %d is already claimed\n",
+ ion_heap_id);
+ goto errfreeipdev;
+ }
+
+ ret = of_property_read_u32(pdev->dev.of_node, "ion-heap-type",
+ &ion_heap_type);
+ if (ret != 0)
+ goto errfreeipdev;
+
+ ret = of_property_read_u32(pdev->dev.of_node, "ion-heap-align",
+ &ion_heap_align);
+ if (ret != 0)
+ goto errfreeipdev;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "memory");
+ /* Not always needed, throw no error if missing */
+ if (res) {
+ /* Fill in some defaults */
+ addr = res->start;
+ size = resource_size(res);
+ }
+
+ switch (ion_heap_type) {
+ case ION_HEAP_TYPE_DMA:
+ if (res) {
+ ret = dma_declare_coherent_memory(&pdev->dev,
+ res->start,
+ res->start,
+ resource_size(res),
+ DMA_MEMORY_MAP |
+ DMA_MEMORY_EXCLUSIVE);
+ if (ret == 0) {
+ ret = -ENODEV;
+ goto errfreeipdev;
+ }
+ }
+ /*
+ * If no memory region declared in dt we assume that
+ * the user is okay with plain dma_alloc_coherent.
+ */
+ break;
+ case ION_HEAP_TYPE_CARVEOUT:
+ case ION_HEAP_TYPE_CHUNK:
+ if (size == 0) {
+ ret = -EIO;
+ goto errfreeipdev;
+ }
+ ipdev->freepage_ptr = alloc_pages_exact(size, GFP_KERNEL);
+ if (ipdev->freepage_ptr) {
+ addr = virt_to_phys(ipdev->freepage_ptr);
+ } else {
+ ret = -ENOMEM;
+ goto errfreeipdev;
+ }
+ break;
+ }
+
+ ipdev->data.id = ion_heap_id;
+ ipdev->data.type = ion_heap_type;
+ ipdev->data.name = ion_heap_name;
+ ipdev->data.align = ion_heap_align;
+ ipdev->data.base = addr;
+ ipdev->data.size = size;
+
+ /* This one make dma_declare_coherent_memory actually work */
+ ipdev->data.priv = &pdev->dev;
+
+ ipdev->heap = ion_heap_create(&ipdev->data);
+ if (!ipdev->heap)
+ goto errfreeipdev;
+
+ /* If it's needed - take care enable clocks */
+ ipdev->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(ipdev->clk))
+ ipdev->clk = NULL;
+ else
+ clk_prepare_enable(ipdev->clk);
+
+ ion_device_add_heap(idev, ipdev->heap);
+ claimed_heap_ids |= (1 << ion_heap_id);
+ ipdev->heap_id = ion_heap_id;
+
+ dev_dbg(&pdev->dev, "heap %s id %d type %d align 0x%x at phys 0x%lx len %lu KiB\n",
+ ion_heap_name, ion_heap_id, ion_heap_type, ion_heap_align,
+ (unsigned long int)addr, ((unsigned long int)(size / 1024)));
+ return 0;
+
+errfreeipdev:
+ kfree(ipdev);
+ dev_err(&pdev->dev, "Failed to register heap: %s\n",
+ ion_heap_name);
+ return -ENOMEM;
+}
+
+static int ion_physmem_remove(struct platform_device *pdev)
+{
+ struct physmem_ion_dev *ipdev = platform_get_drvdata(pdev);
+
+ ion_heap_destroy(ipdev->heap);
+ claimed_heap_ids &= ~(1 << ipdev->heap_id);
+ if (ipdev->need_free_coherent)
+ dma_release_declared_memory(&pdev->dev);
+ if (ipdev->freepage_ptr)
+ free_pages_exact(ipdev->freepage_ptr, ipdev->data.size);
+ kfree(ipdev->heap);
+ if (ipdev->clk)
+ clk_disable_unprepare(ipdev->clk);
+ kfree(ipdev);
+
+ /* We only remove heaps and disable clocks here.
+ * There's no point in nuking the device itself, since:
+ * a). ION driver modules can't be unloaded (yet?)
+ * b). ion_device_destroy() looks like a stub and doesn't
+ * take care to free heaps/clients.
+ * c). I can't think of a scenario where it will be required
+ */
+
+ return 0;
+}
+
+static struct platform_driver ion_physmem_driver = {
+ .probe = ion_physmem_probe,
+ .remove = ion_physmem_remove,
+ .driver = {
+ .name = "ion-physmem",
+ .of_match_table = of_match_ptr(of_match_table),
+ },
+};
+
+static int __init ion_physmem_init(void)
+{
+ return platform_driver_register(&ion_physmem_driver);
+}
+device_initcall(ion_physmem_init);
diff --git a/include/dt-bindings/ion,physmem.h b/include/dt-bindings/ion,physmem.h
new file mode 100644
index 0000000..d26b742
--- /dev/null
+++ b/include/dt-bindings/ion,physmem.h
@@ -0,0 +1,16 @@
+/*
+ * This header provides constants for ION physmem driver.
+ *
+ */
+
+#ifndef _DT_BINDINGS_ION_PHYSMEM_H
+#define _DT_BINDINGS_ION_PHYSMEM_H
+
+#define ION_HEAP_TYPE_SYSTEM 0
+#define ION_HEAP_TYPE_SYSTEM_CONTIG 1
+#define ION_HEAP_TYPE_CARVEOUT 2
+#define ION_HEAP_TYPE_CHUNK 3
+#define ION_HEAP_TYPE_DMA 4
+#define ION_HEAP_TYPE_CUSTOM 5
+
+#endif
--
2.1.4

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