diff options
Diffstat (limited to 'drivers/dma/bestcomm/sram.c')
| -rw-r--r-- | drivers/dma/bestcomm/sram.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/dma/bestcomm/sram.c b/drivers/dma/bestcomm/sram.c new file mode 100644 index 0000000000..0553956f74 --- /dev/null +++ b/drivers/dma/bestcomm/sram.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Simple memory allocator for on-board SRAM + * + * Maintainer : Sylvain Munaut <tnt@246tNt.com> + * + * Copyright (C) 2005 Sylvain Munaut <tnt@246tNt.com> + */ + +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/ioport.h> +#include <linux/of.h> +#include <linux/of_address.h> + +#include <asm/io.h> +#include <asm/mmu.h> + +#include <linux/fsl/bestcomm/sram.h> + + +/* Struct keeping our 'state' */ +struct bcom_sram *bcom_sram = NULL; +EXPORT_SYMBOL_GPL(bcom_sram); /* needed for inline functions */ + + +/* ======================================================================== */ +/* Public API */ +/* ======================================================================== */ +/* DO NOT USE in interrupts, if needed in irq handler, we should use the + _irqsave version of the spin_locks */ + +int bcom_sram_init(struct device_node *sram_node, char *owner) +{ + int rv; + const u32 *regaddr_p; + struct resource res; + unsigned int psize; + + /* Create our state struct */ + if (bcom_sram) { + printk(KERN_ERR "%s: bcom_sram_init: " + "Already initialized !\n", owner); + return -EBUSY; + } + + bcom_sram = kmalloc(sizeof(struct bcom_sram), GFP_KERNEL); + if (!bcom_sram) { + printk(KERN_ERR "%s: bcom_sram_init: " + "Couldn't allocate internal state !\n", owner); + return -ENOMEM; + } + + /* Get address and size of the sram */ + rv = of_address_to_resource(sram_node, 0, &res); + if (rv) { + printk(KERN_ERR "%s: bcom_sram_init: " + "Invalid device node !\n", owner); + goto error_free; + } + + bcom_sram->base_phys = res.start; + bcom_sram->size = resource_size(&res); + + /* Request region */ + if (!request_mem_region(res.start, resource_size(&res), owner)) { + printk(KERN_ERR "%s: bcom_sram_init: " + "Couldn't request region !\n", owner); + rv = -EBUSY; + goto error_free; + } + + /* Map SRAM */ + /* sram is not really __iomem */ + bcom_sram->base_virt = (void *)ioremap(res.start, resource_size(&res)); + + if (!bcom_sram->base_virt) { + printk(KERN_ERR "%s: bcom_sram_init: " + "Map error SRAM zone 0x%08lx (0x%0x)!\n", + owner, (long)bcom_sram->base_phys, bcom_sram->size ); + rv = -ENOMEM; + goto error_release; + } + + /* Create an rheap (defaults to 32 bits word alignment) */ + bcom_sram->rh = rh_create(4); + + /* Attach the free zones */ +#if 0 + /* Currently disabled ... for future use only */ + reg_addr_p = of_get_property(sram_node, "available", &psize); +#else + regaddr_p = NULL; + psize = 0; +#endif + + if (!regaddr_p || !psize) { + /* Attach the whole zone */ + rh_attach_region(bcom_sram->rh, 0, bcom_sram->size); + } else { + /* Attach each zone independently */ + while (psize >= 2 * sizeof(u32)) { + phys_addr_t zbase = of_translate_address(sram_node, regaddr_p); + rh_attach_region(bcom_sram->rh, zbase - bcom_sram->base_phys, regaddr_p[1]); + regaddr_p += 2; + psize -= 2 * sizeof(u32); + } + } + + /* Init our spinlock */ + spin_lock_init(&bcom_sram->lock); + + return 0; + +error_release: + release_mem_region(res.start, resource_size(&res)); +error_free: + kfree(bcom_sram); + bcom_sram = NULL; + + return rv; +} +EXPORT_SYMBOL_GPL(bcom_sram_init); + +void bcom_sram_cleanup(void) +{ + /* Free resources */ + if (bcom_sram) { + rh_destroy(bcom_sram->rh); + iounmap((void __iomem *)bcom_sram->base_virt); + release_mem_region(bcom_sram->base_phys, bcom_sram->size); + kfree(bcom_sram); + bcom_sram = NULL; + } +} +EXPORT_SYMBOL_GPL(bcom_sram_cleanup); + +void* bcom_sram_alloc(int size, int align, phys_addr_t *phys) +{ + unsigned long offset; + + spin_lock(&bcom_sram->lock); + offset = rh_alloc_align(bcom_sram->rh, size, align, NULL); + spin_unlock(&bcom_sram->lock); + + if (IS_ERR_VALUE(offset)) + return NULL; + + *phys = bcom_sram->base_phys + offset; + return bcom_sram->base_virt + offset; +} +EXPORT_SYMBOL_GPL(bcom_sram_alloc); + +void bcom_sram_free(void *ptr) +{ + unsigned long offset; + + if (!ptr) + return; + + offset = ptr - bcom_sram->base_virt; + + spin_lock(&bcom_sram->lock); + rh_free(bcom_sram->rh, offset); + spin_unlock(&bcom_sram->lock); +} +EXPORT_SYMBOL_GPL(bcom_sram_free); |