/* * Sample fifo dma implementation * * Copyright (C) 2010 Stefani Seibold * * Released under the GPL version 2 only. * */ #include #include #include /* * This module shows how to handle fifo dma operations. */ /* fifo size in elements (bytes) */ #define FIFO_SIZE 32 static struct kfifo fifo; static int __init example_init(void) { int i; unsigned int ret; unsigned int nents; struct scatterlist sg[10]; printk(KERN_INFO "DMA fifo test start\n"); if (kfifo_alloc(&fifo, FIFO_SIZE, GFP_KERNEL)) { printk(KERN_WARNING "error kfifo_alloc\n"); return -ENOMEM; } printk(KERN_INFO "queue size: %u\n", kfifo_size(&fifo)); kfifo_in(&fifo, "test", 4); for (i = 0; i != 9; i++) kfifo_put(&fifo, i); /* kick away first byte */ kfifo_skip(&fifo); printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo)); /* * Configure the kfifo buffer to receive data from DMA input. * * .--------------------------------------. * | 0 | 1 | 2 | ... | 12 | 13 | ... | 31 | * |---|------------------|---------------| * \_/ \________________/ \_____________/ * \ \ \ * \ \_allocated data \ * \_*free space* \_*free space* * * We need two different SG entries: one for the free space area at the * end of the kfifo buffer (19 bytes) and another for the first free * byte at the beginning, after the kfifo_skip(). */ sg_init_table(sg, ARRAY_SIZE(sg)); nents = kfifo_dma_in_prepare(&fifo, sg, ARRAY_SIZE(sg), FIFO_SIZE); printk(KERN_INFO "DMA sgl entries: %d\n", nents); if (!nents) { /* fifo is full and no sgl was created */ printk(KERN_WARNING "error kfifo_dma_in_prepare\n"); return -EIO; } /* receive data */ printk(KERN_INFO "scatterlist for receive:\n"); for (i = 0; i < nents; i++) { printk(KERN_INFO "sg[%d] -> " "page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n", i, sg[i].page_link, sg[i].offset, sg[i].length); if (sg_is_last(&sg[i])) break; } /* put here your code to setup and exectute the dma operation */ /* ... */ /* example: zero bytes received */ ret = 0; /* finish the dma operation and update the received data */ kfifo_dma_in_finish(&fifo, ret); /* Prepare to transmit data, example: 8 bytes */ nents = kfifo_dma_out_prepare(&fifo, sg, ARRAY_SIZE(sg), 8); printk(KERN_INFO "DMA sgl entries: %d\n", nents); if (!nents) { /* no data was available and no sgl was created */ printk(KERN_WARNING "error kfifo_dma_out_prepare\n"); return -EIO; } printk(KERN_INFO "scatterlist for transmit:\n"); for (i = 0; i < nents; i++) { printk(KERN_INFO "sg[%d] -> " "page_link 0x%.8lx offset 0x%.8x length 0x%.8x\n", i, sg[i].page_link, sg[i].offset, sg[i].length); if (sg_is_last(&sg[i])) break; } /* put here your code to setup and exectute the dma operation */ /* ... */ /* example: 5 bytes transmitted */ ret = 5; /* finish the dma operation and update the transmitted data */ kfifo_dma_out_finish(&fifo, ret); ret = kfifo_len(&fifo); printk(KERN_INFO "queue len: %u\n", kfifo_len(&fifo)); if (ret != 7) { printk(KERN_WARNING "size mismatch: test failed"); return -EIO; } printk(KERN_INFO "test passed\n"); return 0; } static void __exit example_exit(void) { kfifo_free(&fifo); } module_init(example_init); module_exit(example_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Stefani Seibold "); 4dfc8966019b8b0977b2cb942351f13d2b178'/>
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-01 11:52:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-01 11:52:27 -0800
commit6d04dfc8966019b8b0977b2cb942351f13d2b178 (patch)
tree2d4f239c1daff620704b77a992c1e70ce1ce6b08 /drivers/usb/storage/unusual_usbat.h
parent2883aaea363f7a897ff06d2e6c73ae7aae285bcb (diff)
parent06425c308b92eaf60767bc71d359f4cbc7a561f8 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller: 1) Fix handling of interrupt status in stmmac driver. Just because we have masked the event from generating interrupts, doesn't mean the bit won't still be set in the interrupt status register. From Alexey Brodkin. 2) Fix DMA API debugging splats in gianfar driver, from Arseny Solokha. 3) Fix off-by-one error in __ip6_append_data(), from Vlad Yasevich. 4) cls_flow does not match on icmpv6 codes properly, from Simon Horman. 5) Initial MAC address can be set incorrectly in some scenerios, from Ivan Vecera. 6) Packet header pointer arithmetic fix in ip6_tnl_parse_tlv_end_lim(), from Dan Carpenter. 7) Fix divide by zero in __tcp_select_window(), from Eric Dumazet. 8) Fix crash in iwlwifi when unregistering thermal zone, from Jens Axboe. 9) Check for DMA mapping errors in starfire driver, from Alexey Khoroshilov. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (31 commits) tcp: fix 0 divide in __tcp_select_window() ipv6: pointer math error in ip6_tnl_parse_tlv_enc_lim() net: fix ndo_features_check/ndo_fix_features comment ordering net/sched: matchall: Fix configuration race be2net: fix initial MAC setting ipv6: fix flow labels when the traffic class is non-0 net: thunderx: avoid dereferencing xcv when NULL net/sched: cls_flower: Correct matching on ICMPv6 code ipv6: Paritially checksum full MTU frames net/mlx4_core: Avoid command timeouts during VF driver device shutdown gianfar: synchronize DMA API usage by free_skb_rx_queue w/ gfar_new_page net: ethtool: add support for 2500BaseT and 5000BaseT link modes can: bcm: fix hrtimer/tasklet termination in bcm op removal net: adaptec: starfire: add checks for dma mapping errors net: phy: micrel: KSZ8795 do not set SUPPORTED_[Asym_]Pause can: Fix kernel panic at security_sock_rcv_skb net: macb: Fix 64 bit addressing support for GEM stmmac: Discard masked flags in interrupt status register net/mlx5e: Check ets capability before ets query FW command net/mlx5e: Fix update of hash function/key via ethtool ...
Diffstat (limited to 'drivers/usb/storage/unusual_usbat.h')