[PATCH v2 0/9] Add device tree support for on-chip SRAM

@@ -509,6 +509,14 @@ config USB_SWITCH_FSA9480
 	  stereo and mono audio, video, microphone and UART data to use
 	  a common connector port.
 
+config SRAM
+	bool "Generic on-chip SRAM driver\n"
+	select GENERIC_ALLOCATOR
+	help
+	  This driver allows to declare a memory region to be managed
+	  by the genalloc API. It is supposed to be used for small
+	  on-chip SRAM areas found on many ARM SoCs.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"

@@ -50,3 +50,4 @@ obj-y				+= carma/
 obj-$(CONFIG_USB_SWITCH_FSA9480) += fsa9480.o
 obj-$(CONFIG_ALTERA_STAPL)	+=altera-stapl/
 obj-$(CONFIG_INTEL_MEI)		+= mei/
+obj-$(CONFIG_SRAM)		+= sram.o

@@ -0,0 +1,105 @@
+/*
+ * Generic on-chip SRAM allocation driver
+ *
+ * Copyright (C) 2012 Philipp Zabel, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/genalloc.h>
+
+struct sram_dev {
+	struct gen_pool *pool;
+};
+
+static int __devinit sram_probe(struct platform_device *pdev)
+{
+	void __iomem *virt_base;
+	struct sram_dev *sram;
+	struct resource *res;
+	unsigned long size;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	size = resource_size(res);
+
+	virt_base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!virt_base)
+		return -ENOMEM;
+
+	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
+	if (!sram)
+		return -ENOMEM;
+
+	sram->pool = gen_pool_create(PAGE_SHIFT, -1);
+	if (!sram->pool)
+		return -ENOMEM;
+
+	ret = gen_pool_add_virt(sram->pool, (unsigned long)virt_base,
+				res->start, size, -1);
+	if (ret < 0) {
+		gen_pool_destroy(sram->pool);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, sram);
+
+	dev_dbg(&pdev->dev, "SRAM pool: %ld KiB @ 0x%p\n", size / 1024, virt_base);
+
+	return 0;
+}
+
+static int __devexit sram_remove(struct platform_device *pdev)
+{
+	struct sram_dev *sram = platform_get_drvdata(pdev);
+
+	if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
+		dev_dbg(&pdev->dev, "removed while SRAM allocated\n");
+
+	gen_pool_destroy(sram->pool);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id sram_dt_ids[] = {
+	{ .compatible = "sram" },
+	{ /* sentinel */ }
+};
+#endif
+
+static struct platform_driver sram_driver = {
+	.driver = {
+		.name = "sram",
+		.of_match_table = of_match_ptr(sram_dt_ids),
+	},
+	.probe = sram_probe,
+	.remove = __devexit_p(sram_remove),
+};
+
+module_platform_driver(sram_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Philipp Zabel, Pengutronix");
+MODULE_DESCRIPTION("Generic SRAM allocator driver");

@@ -338,8 +338,8 @@
 			};
 		};
 
-		ocram@f8000000 {
-			compatible = "fsl,imx-ocram";
+		ocram: ocram@f8000000 {
+			compatible = "fsl,imx-ocram", "sram";
 			reg = <0xf8000000 0x20000>;
 		};
 	};

@@ -111,8 +111,8 @@
 		       status = "disabled";
 		};
 
-		ocram@00900000 {
-			compatible = "fsl,imx-ocram";
+		ocram: ocram@00900000 {
+			compatible = "fsl,imx-ocram", "sram";
 			reg = <0x00900000 0x3f000>;
 		};
 

@@ -20,17 +20,11 @@
 
 #ifdef CONFIG_IRAM_ALLOC
 
-int __init iram_init(unsigned long base, unsigned long size);
 void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr);
 void iram_free(unsigned long dma_addr, unsigned int size);
 
 #else
 
-static inline int __init iram_init(unsigned long base, unsigned long size)
-{
-	return -ENOMEM;
-}
-
 static inline void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr)
 {
 	return NULL;

@@ -22,6 +22,8 @@
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/genalloc.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
 #include <mach/iram.h>
 
 static unsigned long iram_phys_base;

@@ -55,15 +57,26 @@ void iram_free(unsigned long addr, unsigned int size)
 }
 EXPORT_SYMBOL(iram_free);
 
-int __init iram_init(unsigned long base, unsigned long size)
+static int __devinit iram_probe(struct platform_device *pdev)
 {
-	iram_phys_base = base;
+	struct resource *res;
+	unsigned long size;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	if (iram_phys_base)
+		return -EBUSY;
+
+	iram_phys_base = res->start;
+	size = resource_size(res);
 
 	iram_pool = gen_pool_create(PAGE_SHIFT, -1);
 	if (!iram_pool)
 		return -ENOMEM;
 
-	gen_pool_add(iram_pool, base, size, -1);
+	gen_pool_add(iram_pool, res->start, size, -1);
 	iram_virt_base = ioremap(iram_phys_base, size);
 	if (!iram_virt_base)
 		return -EIO;

@@ -71,3 +84,28 @@ int __init iram_init(unsigned long base, unsigned long size)
 	pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, iram_virt_base);
 	return 0;
 }
+
+static int __devexit iram_remove(struct platform_device *pdev)
+{
+	gen_pool_destroy(iram_pool);
+	iram_pool = NULL;
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static struct of_device_id iram_dt_ids[] = {
+	{ .compatible = "fsl,imx-iram" },
+	{ /* sentinel */ }
+};
+#endif
+
+static struct platform_driver iram_driver = {
+	.driver = {
+		.name = "imx-iram",
+		.of_match_table = of_match_ptr(iram_dt_ids),
+	},
+	.probe = iram_probe,
+	.remove = __devexit_p(iram_remove),
+};
+
+module_platform_driver(iram_driver);

@@ -82,8 +82,4 @@ config IMX_HAVE_IOMUX_V1
 config ARCH_MXC_IOMUX_V3
 	bool
 
-config IRAM_ALLOC
-	bool
-	select GENERIC_ALLOCATOR
-
 endif

@@ -10,7 +10,6 @@ obj-$(CONFIG_MXC_AVIC) += avic.o
 
 obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o
 obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o
-obj-$(CONFIG_IRAM_ALLOC) += iram_alloc.o
 obj-$(CONFIG_MXC_ULPI) += ulpi.o
 obj-$(CONFIG_MXC_USE_EPIT) += epit.o
 obj-$(CONFIG_MXC_DEBUG_BOARD) += 3ds_debugboard.o

@@ -1,35 +0,0 @@
-/*
- * Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
- * MA 02110-1301, USA.
- */
-#include <linux/errno.h>
-
-#ifdef CONFIG_IRAM_ALLOC
-
-void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr);
-void iram_free(unsigned long dma_addr, unsigned int size);
-
-#else
-
-static inline void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr)
-{
-	return NULL;
-}
-
-static inline void iram_free(unsigned long base, unsigned long size) {}
-
-#endif

@@ -1,116 +0,0 @@
-/*
- * Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
- * MA 02110-1301, USA.
- */
-
-#include <linux/kernel.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/spinlock.h>
-#include <linux/genalloc.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <mach/iram.h>
-
-static struct gen_pool *iram_pool;
-
-void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr)
-{
-	unsigned long virt;
-
-	if (!iram_pool)
-		return NULL;
-
-	virt = gen_pool_alloc(iram_pool, size);
-	pr_debug("iram alloc - %dB@0x%lX\n", size, *dma_addr);
-	if (!virt)
-		return NULL;
-
-	*dma_addr = gen_pool_virt_to_phys(iram_pool, virt);
-	return (void __iomem *)virt;
-}
-EXPORT_SYMBOL(iram_alloc);
-
-void iram_free(unsigned long addr, unsigned int size)
-{
-	if (!iram_pool)
-		return;
-
-	gen_pool_free(iram_pool, addr, size);
-}
-EXPORT_SYMBOL(iram_free);
-
-static int __devinit iram_probe(struct platform_device *pdev)
-{
-	void __iomem *virt_base;
-	struct resource *res;
-	unsigned long size;
-	int ret;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -EINVAL;
-
-	if (iram_pool)
-		return -EBUSY;
-
-	size = resource_size(res);
-
-	virt_base = devm_ioremap(&pdev->dev, res->start, size);
-	if (!virt_base)
-		return -ENOMEM;
-
-	iram_pool = gen_pool_create(PAGE_SHIFT, -1);
-	if (!iram_pool)
-		return -ENOMEM;
-
-	ret = gen_pool_add_virt(iram_pool, (unsigned long)virt_base,
-				res->start, size, -1);
-	if (ret < 0) {
-		gen_pool_destroy(iram_pool);
-		iram_pool = NULL;
-		return ret;
-	}
-
-	pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, virt_base);
-	return 0;
-}
-
-static int __devexit iram_remove(struct platform_device *pdev)
-{
-	gen_pool_destroy(iram_pool);
-	iram_pool = NULL;
-	return 0;
-}
-
-#ifdef CONFIG_OF
-static struct of_device_id iram_dt_ids[] = {
-	{ .compatible = "fsl,imx-iram" },
-	{ /* sentinel */ }
-};
-#endif
-
-static struct platform_driver iram_driver = {
-	.driver = {
-		.name = "imx-iram",
-		.of_match_table = of_match_ptr(iram_dt_ids),
-	},
-	.probe = iram_probe,
-	.remove = __devexit_p(iram_remove),
-};
-
-module_platform_driver(iram_driver);

@@ -33,6 +33,7 @@
  *  General purpose special memory pool descriptor.
  */
 struct gen_pool {
+	struct list_head next_pool;	/* pool in global list */
 	spinlock_t lock;
 	struct list_head chunks;	/* list of chunks in this pool */
 	int min_alloc_order;		/* minimum allocation order */

@@ -78,4 +79,17 @@ extern void gen_pool_for_each_chunk(struct gen_pool *,
 	void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
 extern size_t gen_pool_avail(struct gen_pool *);
 extern size_t gen_pool_size(struct gen_pool *);
+extern struct gen_pool *gen_pool_find_by_phys(phys_addr_t phys);
+
+#ifdef CONFIG_OF
+struct device_node;
+extern struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+	const char *propname, int index);
+#else
+inline struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+	const char *propname, int index)
+{
+	return NULL;
+}
+#endif
 #endif /* __GENALLOC_H__ */

@@ -34,6 +34,11 @@
 #include <linux/rculist.h>
 #include <linux/interrupt.h>
 #include <linux/genalloc.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+
+static LIST_HEAD(pools);
+static DEFINE_SPINLOCK(list_lock);
 
 static int set_bits_ll(unsigned long *addr, unsigned long mask_to_set)
 {

@@ -152,6 +157,9 @@ struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
 		spin_lock_init(&pool->lock);
 		INIT_LIST_HEAD(&pool->chunks);
 		pool->min_alloc_order = min_alloc_order;
+		spin_lock(&list_lock);
+		list_add_rcu(&pool->next_pool, &pools);
+		spin_unlock(&list_lock);
 	}
 	return pool;
 }

@@ -234,6 +242,9 @@ void gen_pool_destroy(struct gen_pool *pool)
 	int order = pool->min_alloc_order;
 	int bit, end_bit;
 
+	spin_lock(&list_lock);
+	list_del_rcu(&pool->next_pool);
+	spin_unlock(&list_lock);
 	list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
 		chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
 		list_del(&chunk->next_chunk);

@@ -400,3 +411,69 @@ size_t gen_pool_size(struct gen_pool *pool)
 	return size;
 }
 EXPORT_SYMBOL_GPL(gen_pool_size);
+
+/**
+ * gen_pool_find_by_phys - find a pool by physical start address
+ * @phys: physical address as added with gen_pool_add_virt
+ *
+ * Returns the pool that contains the chunk starting at phys,
+ * or NULL if not found.
+ */
+struct gen_pool *gen_pool_find_by_phys(phys_addr_t phys)
+{
+	struct gen_pool *pool, *found = NULL;
+	struct gen_pool_chunk *chunk;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pool, &pools, next_pool) {
+		list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) {
+			if (phys == chunk->phys_addr) {
+				found = pool;
+				break;
+			}
+		}
+	}
+	rcu_read_unlock();
+
+	return found;
+}
+EXPORT_SYMBOL_GPL(gen_pool_find_by_phys);
+
+#ifdef CONFIG_OF
+/**
+ * of_get_named_gen_pool - find a pool by the physical address in
+ * @np: device node
+ *
+ * Returns the pool that contains the chunk starting at the physical
+ * address of the np device node, or NULL if not found.
+ */
+struct gen_pool *of_get_named_gen_pool(struct device_node *np,
+	const char *propname, int index)
+{
+	struct property *prop;
+	const __be32 *list;
+	int size;
+	phandle phandle;
+	struct device_node *np_pool;
+	const u32 *reg;
+	u64 addr;
+
+	prop = of_find_property(np, propname, &size);
+	if (!prop)
+		return NULL;
+	list = prop->value;
+	size /= sizeof(*list);
+	phandle = be32_to_cpup(list);
+	np_pool = of_find_node_by_phandle(phandle);
+	if (!np_pool)
+		return NULL;
+	reg = of_get_property(np_pool, "reg", NULL);
+	if (!reg)
+		return NULL;
+	addr = of_translate_address(np_pool, reg);
+	if (addr == OF_BAD_ADDR)
+		return NULL;
+	return gen_pool_find_by_phys((phys_addr_t) addr);
+}
+EXPORT_SYMBOL_GPL(of_get_named_gen_pool);
+#endif /* CONFIG_OF */

@@ -26,25 +26,22 @@
 #include <linux/platform_device.h>
 #include <mach/iram.h>
 
-static unsigned long iram_phys_base;
-static void __iomem *iram_virt_base;
 static struct gen_pool *iram_pool;
 
-static inline void __iomem *iram_phys_to_virt(unsigned long p)
-{
-	return iram_virt_base + (p - iram_phys_base);
-}
-
 void __iomem *iram_alloc(unsigned int size, unsigned long *dma_addr)
 {
+	unsigned long virt;
+
 	if (!iram_pool)
 		return NULL;
 
-	*dma_addr = gen_pool_alloc(iram_pool, size);
+	virt = gen_pool_alloc(iram_pool, size);
 	pr_debug("iram alloc - %dB@0x%lX\n", size, *dma_addr);
-	if (!*dma_addr)
+	if (!virt)
 		return NULL;
-	return iram_phys_to_virt(*dma_addr);
+
+	*dma_addr = gen_pool_virt_to_phys(iram_pool, virt);
+	return (void __iomem *)virt;
 }
 EXPORT_SYMBOL(iram_alloc);
 

@@ -59,29 +56,37 @@ EXPORT_SYMBOL(iram_free);
 
 static int __devinit iram_probe(struct platform_device *pdev)
 {
+	void __iomem *virt_base;
 	struct resource *res;
 	unsigned long size;
+	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -EINVAL;
 
-	if (iram_phys_base)
+	if (iram_pool)
 		return -EBUSY;
 
-	iram_phys_base = res->start;
 	size = resource_size(res);
 
+	virt_base = devm_ioremap(&pdev->dev, res->start, size);
+	if (!virt_base)
+		return -ENOMEM;
+
 	iram_pool = gen_pool_create(PAGE_SHIFT, -1);
 	if (!iram_pool)
 		return -ENOMEM;
 
-	gen_pool_add(iram_pool, res->start, size, -1);
-	iram_virt_base = ioremap(iram_phys_base, size);
-	if (!iram_virt_base)
-		return -EIO;
+	ret = gen_pool_add_virt(iram_pool, (unsigned long)virt_base,
+				res->start, size, -1);
+	if (ret < 0) {
+		gen_pool_destroy(iram_pool);
+		iram_pool = NULL;
+		return ret;
+	}
 
-	pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, iram_virt_base);
+	pr_debug("i.MX IRAM pool: %ld KB@0x%p\n", size / 1024, virt_base);
 	return 0;
 }
 

@@ -337,5 +337,10 @@
 				status = "disabled";
 			};
 		};
+
+		ocram@f8000000 {
+			compatible = "fsl,imx-ocram";
+			reg = <0xf8000000 0x20000>;
+		};
 	};
 };

@@ -111,6 +111,11 @@
 		       status = "disabled";
 		};
 
+		ocram@00900000 {
+			compatible = "fsl,imx-ocram";
+			reg = <0x00900000 0x3f000>;
+		};
+
 		timer@00a00600 {
 			compatible = "arm,cortex-a9-twd-timer";
 			reg = <0x00a00600 0x20>;