diff options
Diffstat (limited to 'drivers/misc/carma/carma-fpga.c')
| -rw-r--r-- | drivers/misc/carma/carma-fpga.c | 1507 |
1 files changed, 0 insertions, 1507 deletions
diff --git a/drivers/misc/carma/carma-fpga.c b/drivers/misc/carma/carma-fpga.c deleted file mode 100644 index 5aba3fd789de..000000000000 --- a/drivers/misc/carma/carma-fpga.c +++ /dev/null @@ -1,1507 +0,0 @@ -/* - * CARMA DATA-FPGA Access Driver - * - * Copyright (c) 2009-2011 Ira W. Snyder <iws@ovro.caltech.edu> - * - * 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. - */ - -/* - * FPGA Memory Dump Format - * - * FPGA #0 control registers (32 x 32-bit words) - * FPGA #1 control registers (32 x 32-bit words) - * FPGA #2 control registers (32 x 32-bit words) - * FPGA #3 control registers (32 x 32-bit words) - * SYSFPGA control registers (32 x 32-bit words) - * FPGA #0 correlation array (NUM_CORL0 correlation blocks) - * FPGA #1 correlation array (NUM_CORL1 correlation blocks) - * FPGA #2 correlation array (NUM_CORL2 correlation blocks) - * FPGA #3 correlation array (NUM_CORL3 correlation blocks) - * - * Each correlation array consists of: - * - * Correlation Data (2 x NUM_LAGSn x 32-bit words) - * Pipeline Metadata (2 x NUM_METAn x 32-bit words) - * Quantization Counters (2 x NUM_QCNTn x 32-bit words) - * - * The NUM_CORLn, NUM_LAGSn, NUM_METAn, and NUM_QCNTn values come from - * the FPGA configuration registers. They do not change once the FPGA's - * have been programmed, they only change on re-programming. - */ - -/* - * Basic Description: - * - * This driver is used to capture correlation spectra off of the four data - * processing FPGAs. The FPGAs are often reprogrammed at runtime, therefore - * this driver supports dynamic enable/disable of capture while the device - * remains open. - * - * The nominal capture rate is 64Hz (every 15.625ms). To facilitate this fast - * capture rate, all buffers are pre-allocated to avoid any potentially long - * running memory allocations while capturing. - * - * There are two lists and one pointer which are used to keep track of the - * different states of data buffers. - * - * 1) free list - * This list holds all empty data buffers which are ready to receive data. - * - * 2) inflight pointer - * This pointer holds the currently inflight data buffer. This buffer is having - * data copied into it by the DMA engine. - * - * 3) used list - * This list holds data buffers which have been filled, and are waiting to be - * read by userspace. - * - * All buffers start life on the free list, then move successively to the - * inflight pointer, and then to the used list. After they have been read by - * userspace, they are moved back to the free list. The cycle repeats as long - * as necessary. - * - * It should be noted that all buffers are mapped and ready for DMA when they - * are on any of the three lists. They are only unmapped when they are in the - * process of being read by userspace. - */ - -/* - * Notes on the IRQ masking scheme: - * - * The IRQ masking scheme here is different than most other hardware. The only - * way for the DATA-FPGAs to detect if the kernel has taken too long to copy - * the data is if the status registers are not cleared before the next - * correlation data dump is ready. - * - * The interrupt line is connected to the status registers, such that when they - * are cleared, the interrupt is de-asserted. Therein lies our problem. We need - * to schedule a long-running DMA operation and return from the interrupt - * handler quickly, but we cannot clear the status registers. - * - * To handle this, the system controller FPGA has the capability to connect the - * interrupt line to a user-controlled GPIO pin. This pin is driven high - * (unasserted) and left that way. To mask the interrupt, we change the - * interrupt source to the GPIO pin. Tada, we hid the interrupt. :) - */ - -#include <linux/of_address.h> -#include <linux/of_irq.h> -#include <linux/of_platform.h> -#include <linux/dma-mapping.h> -#include <linux/miscdevice.h> -#include <linux/interrupt.h> -#include <linux/dmaengine.h> -#include <linux/seq_file.h> -#include <linux/highmem.h> -#include <linux/debugfs.h> -#include <linux/vmalloc.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/poll.h> -#include <linux/slab.h> -#include <linux/kref.h> -#include <linux/io.h> - -/* system controller registers */ -#define SYS_IRQ_SOURCE_CTL 0x24 -#define SYS_IRQ_OUTPUT_EN 0x28 -#define SYS_IRQ_OUTPUT_DATA 0x2C -#define SYS_IRQ_INPUT_DATA 0x30 -#define SYS_FPGA_CONFIG_STATUS 0x44 - -/* GPIO IRQ line assignment */ -#define IRQ_CORL_DONE 0x10 - -/* FPGA registers */ -#define MMAP_REG_VERSION 0x00 -#define MMAP_REG_CORL_CONF1 0x08 -#define MMAP_REG_CORL_CONF2 0x0C -#define MMAP_REG_STATUS 0x48 - -#define SYS_FPGA_BLOCK 0xF0000000 - -#define DATA_FPGA_START 0x400000 -#define DATA_FPGA_SIZE 0x80000 - -static const char drv_name[] = "carma-fpga"; - -#define NUM_FPGA 4 - -#define MIN_DATA_BUFS 8 -#define MAX_DATA_BUFS 64 - -struct fpga_info { - unsigned int num_lag_ram; - unsigned int blk_size; -}; - -struct data_buf { - struct list_head entry; - void *vaddr; - struct scatterlist *sglist; - int sglen; - int nr_pages; - size_t size; -}; - -struct fpga_device { - /* character device */ - struct miscdevice miscdev; - struct device *dev; - struct mutex mutex; - - /* reference count */ - struct kref ref; - - /* FPGA registers and information */ - struct fpga_info info[NUM_FPGA]; - void __iomem *regs; - int irq; - - /* FPGA Physical Address/Size Information */ - resource_size_t phys_addr; - size_t phys_size; - - /* DMA structures */ - struct sg_table corl_table; - unsigned int corl_nents; - struct dma_chan *chan; - - /* Protection for all members below */ - spinlock_t lock; - - /* Device enable/disable flag */ - bool enabled; - - /* Correlation data buffers */ - wait_queue_head_t wait; - struct list_head free; - struct list_head used; - struct data_buf *inflight; - - /* Information about data buffers */ - unsigned int num_dropped; - unsigned int num_buffers; - size_t bufsize; - struct dentry *dbg_entry; -}; - -struct fpga_reader { - struct fpga_device *priv; - struct data_buf *buf; - off_t buf_start; -}; - -static void fpga_device_release(struct kref *ref) -{ - struct fpga_device *priv = container_of(ref, struct fpga_device, ref); - - /* the last reader has exited, cleanup the last bits */ - mutex_destroy(&priv->mutex); - kfree(priv); -} - -/* - * Data Buffer Allocation Helpers - */ - -static int carma_dma_init(struct data_buf *buf, int nr_pages) -{ - struct page *pg; - int i; - - buf->vaddr = vmalloc_32(nr_pages << PAGE_SHIFT); - if (NULL == buf->vaddr) { - pr_debug("vmalloc_32(%d pages) failed\n", nr_pages); - return -ENOMEM; - } - - pr_debug("vmalloc is at addr 0x%08lx, size=%d\n", - (unsigned long)buf->vaddr, - nr_pages << PAGE_SHIFT); - - memset(buf->vaddr, 0, nr_pages << PAGE_SHIFT); - buf->nr_pages = nr_pages; - - buf->sglist = vzalloc(buf->nr_pages * sizeof(*buf->sglist)); - if (NULL == buf->sglist) - goto vzalloc_err; - - sg_init_table(buf->sglist, buf->nr_pages); - for (i = 0; i < buf->nr_pages; i++) { - pg = vmalloc_to_page(buf->vaddr + i * PAGE_SIZE); - if (NULL == pg) - goto vmalloc_to_page_err; - sg_set_page(&buf->sglist[i], pg, PAGE_SIZE, 0); - } - return 0; - -vmalloc_to_page_err: - vfree(buf->sglist); - buf->sglist = NULL; -vzalloc_err: - vfree(buf->vaddr); - buf->vaddr = NULL; - return -ENOMEM; -} - -static int carma_dma_map(struct device *dev, struct data_buf *buf) -{ - buf->sglen = dma_map_sg(dev, buf->sglist, - buf->nr_pages, DMA_FROM_DEVICE); - - if (0 == buf->sglen) { - pr_warn("%s: dma_map_sg failed\n", __func__); - return -ENOMEM; - } - return 0; -} - -static int carma_dma_unmap(struct device *dev, struct data_buf *buf) -{ - if (!buf->sglen) - return 0; - - dma_unmap_sg(dev, buf->sglist, buf->sglen, DMA_FROM_DEVICE); - buf->sglen = 0; - return 0; -} - -/** - * data_free_buffer() - free a single data buffer and all allocated memory - * @buf: the buffer to free - * - * This will free all of the pages allocated to the given data buffer, and - * then free the structure itself - */ -static void data_free_buffer(struct data_buf *buf) -{ - /* It is ok to free a NULL buffer */ - if (!buf) - return; - - /* free all memory */ - vfree(buf->sglist); - vfree(buf->vaddr); - kfree(buf); -} - -/** - * data_alloc_buffer() - allocate and fill a data buffer with pages - * @bytes: the number of bytes required - * - * This allocates all space needed for a data buffer. It must be mapped before - * use in a DMA transaction using carma_dma_map(). - * - * Returns NULL on failure - */ -static struct data_buf *data_alloc_buffer(const size_t bytes) -{ - unsigned int nr_pages; - struct data_buf *buf; - int ret; - - /* calculate the number of pages necessary */ - nr_pages = DIV_ROUND_UP(bytes, PAGE_SIZE); - - /* allocate the buffer structure */ - buf = kzalloc(sizeof(*buf), GFP_KERNEL); - if (!buf) - goto out_return; - - /* initialize internal fields */ - INIT_LIST_HEAD(&buf->entry); - buf->size = bytes; - - /* allocate the buffer */ - ret = carma_dma_init(buf, nr_pages); - if (ret) - goto out_free_buf; - - return buf; - -out_free_buf: - kfree(buf); -out_return: - return NULL; -} - -/** - * data_free_buffers() - free all allocated buffers - * @priv: the driver's private data structure - * - * Free all buffers allocated by the driver (except those currently in the - * process of being read by userspace). - * - * LOCKING: must hold dev->mutex - * CONTEXT: user - */ -static void data_free_buffers(struct fpga_device *priv) -{ - struct data_buf *buf, *tmp; - - /* the device should be stopped, no DMA in progress */ - BUG_ON(priv->inflight != NULL); - - list_for_each_entry_safe(buf, tmp, &priv->free, entry) { - list_del_init(&buf->entry); - carma_dma_unmap(priv->dev, buf); - data_free_buffer(buf); - } - - list_for_each_entry_safe(buf, tmp, &priv->used, entry) { - list_del_init(&buf->entry); - carma_dma_unmap(priv->dev, buf); - data_free_buffer(buf); - } - - priv->num_buffers = 0; - priv->bufsize = 0; -} - -/** - * data_alloc_buffers() - allocate 1 seconds worth of data buffers - * @priv: the driver's private data structure - * - * Allocate enough buffers for a whole second worth of data - * - * This routine will attempt to degrade nicely by succeeding even if a full - * second worth of data buffers could not be allocated, as long as a minimum - * number were allocated. In this case, it will print a message to the kernel - * log. - * - * The device must not be modifying any lists when this is called. - * - * CONTEXT: user - * LOCKING: must hold dev->mutex - * - * Returns 0 on success, -ERRNO otherwise - */ -static int data_alloc_buffers(struct fpga_device *priv) -{ - struct data_buf *buf; - int i, ret; - - for (i = 0; i < MAX_DATA_BUFS; i++) { - - /* allocate a buffer */ - buf = data_alloc_buffer(priv->bufsize); - if (!buf) - break; - - /* map it for DMA */ - ret = carma_dma_map(priv->dev, buf); - if (ret) { - data_free_buffer(buf); - break; - } - - /* add it to the list of free buffers */ - list_add_tail(&buf->entry, &priv->free); - priv->num_buffers++; - } - - /* Make sure we allocated the minimum required number of buffers */ - if (priv->num_buffers < MIN_DATA_BUFS) { - dev_err(priv->dev, "Unable to allocate enough data buffers\n"); - data_free_buffers(priv); - return -ENOMEM; - } - - /* Warn if we are running in a degraded state, but do not fail */ - if (priv->num_buffers < MAX_DATA_BUFS) { - dev_warn(priv->dev, - "Unable to allocate %d buffers, using %d buffers instead\n", - MAX_DATA_BUFS, i); - } - - return 0; -} - -/* - * DMA Operations Helpers - */ - -/** - * fpga_start_addr() - get the physical address a DATA-FPGA - * @priv: the driver's private data structure - * @fpga: the DATA-FPGA number (zero based) - */ -static dma_addr_t fpga_start_addr(struct fpga_device *priv, unsigned int fpga) -{ - return priv->phys_addr + 0x400000 + (0x80000 * fpga); -} - -/** - * fpga_block_addr() - get the physical address of a correlation data block - * @priv: the driver's private data structure - * @fpga: the DATA-FPGA number (zero based) - * @blknum: the correlation block number (zero based) - */ -static dma_addr_t fpga_block_addr(struct fpga_device *priv, unsigned int fpga, - unsigned int blknum) -{ - return fpga_start_addr(priv, fpga) + (0x10000 * (1 + blknum)); -} - -#define REG_BLOCK_SIZE (32 * 4) - -/** - * data_setup_corl_table() - create the scatterlist for correlation dumps - * @priv: the driver's private data structure - * - * Create the scatterlist for transferring a correlation dump from the - * DATA FPGAs. This structure will be reused for each buffer than needs - * to be filled with correlation data. - * - * Returns 0 on success, -ERRNO otherwise - */ -static int data_setup_corl_table(struct fpga_device *priv) -{ - struct sg_table *table = &priv->corl_table; - struct scatterlist *sg; - struct fpga_info *info; - int i, j, ret; - - /* Calculate the number of entries needed */ - priv->corl_nents = (1 + NUM_FPGA) * REG_BLOCK_SIZE; - for (i = 0; i < NUM_FPGA; i++) - priv->corl_nents += priv->info[i].num_lag_ram; - - /* Allocate the scatterlist table */ - ret = sg_alloc_table(table, priv->corl_nents, GFP_KERNEL); - if (ret) { - dev_err(priv->dev, "unable to allocate DMA table\n"); - return ret; - } - - /* Add the DATA FPGA registers to the scatterlist */ - sg = table->sgl; - for (i = 0; i < NUM_FPGA; i++) { - sg_dma_address(sg) = fpga_start_addr(priv, i); - sg_dma_len(sg) = REG_BLOCK_SIZE; - sg = sg_next(sg); - } - - /* Add the SYS-FPGA registers to the scatterlist */ - sg_dma_address(sg) = SYS_FPGA_BLOCK; - sg_dma_len(sg) = REG_BLOCK_SIZE; - sg = sg_next(sg); - - /* Add the FPGA correlation data blocks to the scatterlist */ - for (i = 0; i < NUM_FPGA; i++) { - info = &priv->info[i]; - for (j = 0; j < info->num_lag_ram; j++) { - sg_dma_address(sg) = fpga_block_addr(priv, i, j); - sg_dma_len(sg) = info->blk_size; - sg = sg_next(sg); - } - } - - /* - * All physical addresses and lengths are present in the structure - * now. It can be reused for every FPGA DATA interrupt - */ - return 0; -} - -/* - * FPGA Register Access Helpers - */ - -static void fpga_write_reg(struct fpga_device *priv, unsigned int fpga, - unsigned int reg, u32 val) -{ - const int fpga_start = DATA_FPGA_START + (fpga * DATA_FPGA_SIZE); - iowrite32be(val, priv->regs + fpga_start + reg); -} - -static u32 fpga_read_reg(struct fpga_device *priv, unsigned int fpga, - unsigned int reg) -{ - const int fpga_start = DATA_FPGA_START + (fpga * DATA_FPGA_SIZE); - return ioread32be(priv->regs + fpga_start + reg); -} - -/** - * data_calculate_bufsize() - calculate the data buffer size required - * @priv: the driver's private data structure - * - * Calculate the total buffer size needed to hold a single block - * of correlation data - * - * CONTEXT: user - * - * Returns 0 on success, -ERRNO otherwise - */ -static int data_calculate_bufsize(struct fpga_device *priv) -{ - u32 num_corl, num_lags, num_meta, num_qcnt, num_pack; - u32 conf1, conf2, version; - u32 num_lag_ram, blk_size; - int i; - - /* Each buffer starts with the 5 FPGA register areas */ - priv->bufsize = (1 + NUM_FPGA) * REG_BLOCK_SIZE; - - /* Read and store the configuration data for each FPGA */ - for (i = 0; i < NUM_FPGA; i++) { - version = fpga_read_reg(priv, i, MMAP_REG_VERSION); - conf1 = fpga_read_reg(priv, i, MMAP_REG_CORL_CONF1); - conf2 = fpga_read_reg(priv, i, MMAP_REG_CORL_CONF2); - - /* minor version 2 and later */ - if ((version & 0x000000FF) >= 2) { - num_corl = (conf1 & 0x000000F0) >> 4; - num_pack = (conf1 & 0x00000F00) >> 8; - num_lags = (conf1 & 0x00FFF000) >> 12; - num_meta = (conf1 & 0x7F000000) >> 24; - num_qcnt = (conf2 & 0x00000FFF) >> 0; - } else { - num_corl = (conf1 & 0x000000F0) >> 4; - num_pack = 1; /* implied */ - num_lags = (conf1 & 0x000FFF00) >> 8; - num_meta = (conf1 & 0x7FF00000) >> 20; - num_qcnt = (conf2 & 0x00000FFF) >> 0; - } - - num_lag_ram = (num_corl + num_pack - 1) / num_pack; - blk_size = ((num_pack * num_lags) + num_meta + num_qcnt) * 8; - - priv->info[i].num_lag_ram = num_lag_ram; - priv->info[i].blk_size = blk_size; - priv->bufsize += num_lag_ram * blk_size; - - dev_dbg(priv->dev, "FPGA %d NUM_CORL: %d\n", i, num_corl); - dev_dbg(priv->dev, "FPGA %d NUM_PACK: %d\n", i, num_pack); - dev_dbg(priv->dev, "FPGA %d NUM_LAGS: %d\n", i, num_lags); - dev_dbg(priv->dev, "FPGA %d NUM_META: %d\n", i, num_meta); - dev_dbg(priv->dev, "FPGA %d NUM_QCNT: %d\n", i, num_qcnt); - dev_dbg(priv->dev, "FPGA %d BLK_SIZE: %d\n", i, blk_size); - } - - dev_dbg(priv->dev, "TOTAL BUFFER SIZE: %zu bytes\n", priv->bufsize); - return 0; -} - -/* - * Interrupt Handling - */ - -/** - * data_disable_interrupts() - stop the device from generating interrupts - * @priv: the driver's private data structure - * - * Hide interrupts by switching to GPIO interrupt source - * - * LOCKING: must hold dev->lock - */ -static void data_disable_interrupts(struct fpga_device *priv) -{ - /* hide the interrupt by switching the IRQ driver to GPIO */ - iowrite32be(0x2F, priv->regs + SYS_IRQ_SOURCE_CTL); -} - -/** - * data_enable_interrupts() - allow the device to generate interrupts - * @priv: the driver's private data structure - * - * Unhide interrupts by switching to the FPGA interrupt source. At the - * same time, clear the DATA-FPGA status registers. - * - * LOCKING: must hold dev->lock - */ -static void data_enable_interrupts(struct fpga_device *priv) -{ - /* clear the actual FPGA corl_done interrupt */ - fpga_write_reg(priv, 0, MMAP_REG_STATUS, 0x0); - fpga_write_reg(priv, 1, MMAP_REG_STATUS, 0x0); - fpga_write_reg(priv, 2, MMAP_REG_STATUS, 0x0); - fpga_write_reg(priv, 3, MMAP_REG_STATUS, 0x0); - - /* flush the writes */ - fpga_read_reg(priv, 0, MMAP_REG_STATUS); - fpga_read_reg(priv, 1, MMAP_REG_STATUS); - fpga_read_reg(priv, 2, MMAP_REG_STATUS); - fpga_read_reg(priv, 3, MMAP_REG_STATUS); - - /* switch back to the external interrupt source */ - iowrite32be(0x3F, priv->regs + SYS_IRQ_SOURCE_CTL); -} - -/** - * data_dma_cb() - DMAEngine callback for DMA completion - * @data: the driver's private data structure - * - * Complete a DMA transfer from the DATA-FPGA's - * - * This is called via the DMA callback mechanism, and will handle moving the - * completed DMA transaction to the used list, and then wake any processes - * waiting for new data - * - * CONTEXT: any, softirq expected - */ -static void data_dma_cb(void *data) -{ - struct fpga_device *priv = data; - unsigned long flags; - - spin_lock_irqsave(&priv->lock, flags); - - /* If there is no inflight buffer, we've got a bug */ - BUG_ON(priv->inflight == NULL); - - /* Move the inflight buffer onto the used list */ - list_move_tail(&priv->inflight->entry, &priv->used); - priv->inflight = NULL; - - /* - * If data dumping is still enabled, then clear the FPGA - * status registers and re-enable FPGA interrupts - */ - if (priv->enabled) - data_enable_interrupts(priv); - - spin_unlock_irqrestore(&priv->lock, flags); - - /* - * We've changed both the inflight and used lists, so we need - * to wake up any processes that are blocking for those events - */ - wake_up(&priv->wait); -} - -/** - * data_submit_dma() - prepare and submit the required DMA to fill a buffer - * @priv: the driver's private data structure - * @buf: the data buffer - * - * Prepare and submit the necessary DMA transactions to fill a correlation - * data buffer. - * - * LOCKING: must hold dev->lock - * CONTEXT: hardirq only - * - * Returns 0 on success, -ERRNO otherwise - */ -static int data_submit_dma(struct fpga_device *priv, struct data_buf *buf) -{ - struct scatterlist *dst_sg, *src_sg; - unsigned int dst_nents, src_nents; - struct dma_chan *chan = priv->chan; - struct dma_async_tx_descriptor *tx; - dma_cookie_t cookie; - dma_addr_t dst, src; - unsigned long dma_flags = 0; - - dst_sg = buf->sglist; - dst_nents = buf->sglen; - - src_sg = priv->corl_table.sgl; - src_nents = priv->corl_nents; - - /* - * All buffers passed to this function should be ready and mapped - * for DMA already. Therefore, we don't need to do anything except - * submit it to the Freescale DMA Engine for processing - */ - - /* setup the scatterlist to scatterlist transfer */ - tx = chan->device->device_prep_dma_sg(chan, - dst_sg, dst_nents, - src_sg, src_nents, - 0); - if (!tx) { - dev_err(priv->dev, "unable to prep scatterlist DMA\n"); - return -ENOMEM; - } - - /* submit the transaction to the DMA controller */ - cookie = tx->tx_submit(tx); - if (dma_submit_error(cookie)) { - dev_err(priv->dev, "unable to submit scatterlist DMA\n"); - return -ENOMEM; - } - - /* Prepare the re-read of the SYS-FPGA block */ - dst = sg_dma_address(dst_sg) + (NUM_FPGA * REG_BLOCK_SIZE); - src = SYS_FPGA_BLOCK; - tx = chan->device->device_prep_dma_memcpy(chan, dst, src, - REG_BLOCK_SIZE, - dma_flags); - if (!tx) { - dev_err(priv->dev, "unable to prep SYS-FPGA DMA\n"); - return -ENOMEM; - } - - /* Setup the callback */ - tx->callback = data_dma_cb; - tx->callback_param = priv; - - /* submit the transaction to the DMA controller */ - cookie = tx->tx_submit(tx); - if (dma_submit_error(cookie)) { - dev_err(priv->dev, "unable to submit SYS-FPGA DMA\n"); - return -ENOMEM; - } - - return 0; -} - -#define CORL_DONE 0x1 -#define CORL_ERR 0x2 - -static irqreturn_t data_irq(int irq, void *dev_id) -{ - struct fpga_device *priv = dev_id; - bool submitted = false; - struct data_buf *buf; - u32 status; - int i; - - /* detect spurious interrupts via FPGA status */ - for (i = 0; i < 4; i++) { - status = fpga_read_reg(priv, i, MMAP_REG_STATUS); - if (!(status & (CORL_DONE | CORL_ERR))) { - dev_err(priv->dev, "spurious irq detected (FPGA)\n"); - return IRQ_NONE; - } - } - - /* detect spurious interrupts via raw IRQ pin readback */ - status = ioread32be(priv->regs + SYS_IRQ_INPUT_DATA); - if (status & IRQ_CORL_DONE) { - dev_err(priv->dev, "spurious irq detected (IRQ)\n"); - return IRQ_NONE; - } - - spin_lock(&priv->lock); - - /* - * This is an error case that should never happen. - * - * If this driver has a bug and manages to re-enable interrupts while - * a DMA is in progress, then we will hit this statement and should - * start paying attention immediately. - */ - BUG_ON(priv->inflight != NULL); - - /* hide the interrupt by switching the IRQ driver to GPIO */ - data_disable_interrupts(priv); - - /* If there are no free buffers, drop this data */ - if (list_empty(&priv->free)) { - priv->num_dropped++; - goto out; - } - - buf = list_first_entry(&priv->free, struct data_buf, entry); - list_del_init(&buf->entry); - BUG_ON(buf->size != priv->bufsize); - - /* Submit a DMA transfer to get the correlation data */ - if (data_submit_dma(priv, buf)) { - dev_err(priv->dev, "Unable to setup DMA transfer\n"); - list_move_tail(&buf->entry, &priv->free); - goto out; - } - - /* Save the buffer for the DMA callback */ - priv->inflight = buf; - submitted = true; - - /* Start the DMA Engine */ - dma_async_issue_pending(priv->chan); - -out: - /* If no DMA was submitted, re-enable interrupts */ - if (!submitted) - data_enable_interrupts(priv); - - spin_unlock(&priv->lock); - return IRQ_HANDLED; -} - -/* - * Realtime Device Enable Helpers - */ - -/** - * data_device_enable() - enable the device for buffered dumping - * @priv: the driver's private data structure - * - * Enable the device for buffered dumping. Allocates buffers and hooks up - * the interrupt handler. When this finishes, data will come pouring in. - * - * LOCKING: must hold dev->mutex - * CONTEXT: user context only - * - * Returns 0 on success, -ERRNO otherwise - */ -static int data_device_enable(struct fpga_device *priv) -{ - bool enabled; - u32 val; - int ret; - - /* multiple enables are safe: they do nothing */ - spin_lock_irq(&priv->lock); - enabled = priv->enabled; - spin_unlock_irq(&priv->lock); - if (enabled) - return 0; - - /* check that the FPGAs are programmed */ - val = ioread32be(priv->regs + SYS_FPGA_CONFIG_STATUS); - if (!(val & (1 << 18))) { - dev_err(priv->dev, "DATA-FPGAs are not enabled\n"); - return -ENODATA; - } - - /* read the FPGAs to calculate the buffer size */ - ret = data_calculate_bufsize(priv); - if (ret) { - dev_err(priv->dev, "unable to calculate buffer size\n"); - goto out_error; - } - - /* allocate the correlation data buffers */ - ret = data_alloc_buffers(priv); - if (ret) { - dev_err(priv->dev, "unable to allocate buffers\n"); - goto out_error; - } - - /* setup the source scatterlist for dumping correlation data */ - ret = data_setup_corl_table(priv); - if (ret) { - dev_err(priv->dev, "unable to setup correlation DMA table\n"); - goto out_error; - } - - /* prevent the FPGAs from generating interrupts */ - data_disable_interrupts(priv); - - /* hookup the irq handler */ - ret = request_irq(priv->irq, data_irq, IRQF_SHARED, drv_name, priv); - if (ret) { - dev_err(priv->dev, "unable to request IRQ handler\n"); - goto out_error; - } - - /* allow the DMA callback to re-enable FPGA interrupts */ - spin_lock_irq(&priv->lock); - priv->enabled = true; - spin_unlock_irq(&priv->lock); - - /* allow the FPGAs to generate interrupts */ - data_enable_interrupts(priv); - return 0; - -out_error: - sg_free_table(&priv->corl_table); - priv->corl_nents = 0; - - data_free_buffers(priv); - return ret; -} - -/** - * data_device_disable() - disable the device for buffered dumping - * @priv: the driver's private data structure - * - * Disable the device for buffered dumping. Stops new DMA transactions from - * being generated, waits for all outstanding DMA to complete, and then frees - * all buffers. - * - * LOCKING: must hold dev->mutex - * CONTEXT: user only - * - * Returns 0 on success, -ERRNO otherwise - */ -static int data_device_disable(struct fpga_device *priv) -{ - spin_lock_irq(&priv->lock); - - /* allow multiple disable */ - if (!priv->enabled) { - spin_unlock_irq(&priv->lock); - return 0; - } - - /* - * Mark the device disabled - * - * This stops DMA callbacks from re-enabling interrupts - */ - priv->enabled = false; - - /* prevent the FPGAs from generating interrupts */ - data_disable_interrupts(priv); - - /* wait until all ongoing DMA has finished */ - while (priv->inflight != NULL) { - spin_unlock_irq(&priv->lock); - wait_event(priv->wait, priv->inflight == NULL); - spin_lock_irq(&priv->lock); - } - - spin_unlock_irq(&priv->lock); - - /* unhook the irq handler */ - free_irq(priv->irq, priv); - - /* free the correlation table */ - sg_free_table(&priv->corl_table); - priv->corl_nents = 0; - - /* free all buffers: the free and used lists are not being changed */ - data_free_buffers(priv); - return 0; -} - -/* - * DEBUGFS Interface - */ -#ifdef CONFIG_DEBUG_FS - -/* - * Count the number of entries in the given list - */ -static unsigned int list_num_entries(struct list_head *list) -{ - struct list_head *entry; - unsigned int ret = 0; - - list_for_each(entry, list) - ret++; - - return ret; -} - -static int data_debug_show(struct seq_file *f, void *offset) -{ - struct fpga_device *priv = f->private; - - spin_lock_irq(&priv->lock); - - seq_printf(f, "enabled: %d\n", priv->enabled); - seq_printf(f, "bufsize: %d\n", priv->bufsize); - seq_printf(f, "num_buffers: %d\n", priv->num_buffers); - seq_printf(f, "num_free: %d\n", list_num_entries(&priv->free)); - seq_printf(f, "inflight: %d\n", priv->inflight != NULL); - seq_printf(f, "num_used: %d\n", list_num_entries(&priv->used)); - seq_printf(f, "num_dropped: %d\n", priv->num_dropped); - - spin_unlock_irq(&priv->lock); - return 0; -} - -static int data_debug_open(struct inode *inode, struct file *file) -{ - return single_open(file, data_debug_show, inode->i_private); -} - -static const struct file_operations data_debug_fops = { - .owner = THIS_MODULE, - .open = data_debug_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -static int data_debugfs_init(struct fpga_device *priv) -{ - priv->dbg_entry = debugfs_create_file(drv_name, S_IRUGO, NULL, priv, - &data_debug_fops); - return PTR_ERR_OR_ZERO(priv->dbg_entry); -} - -static void data_debugfs_exit(struct fpga_device *priv) -{ - debugfs_remove(priv->dbg_entry); -} - -#else - -static inline int data_debugfs_init(struct fpga_device *priv) -{ - return 0; -} - -static inline void data_debugfs_exit(struct fpga_device *priv) -{ -} - -#endif /* CONFIG_DEBUG_FS */ - -/* - * SYSFS Attributes - */ - -static ssize_t data_en_show(struct device *dev, struct device_attribute *attr, - char *buf) -{ - struct fpga_device *priv = dev_get_drvdata(dev); - int ret; - - spin_lock_irq(&priv->lock); - ret = snprintf(buf, PAGE_SIZE, "%u\n", priv->enabled); - spin_unlock_irq(&priv->lock); - - return ret; -} - -static ssize_t data_en_set(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) -{ - struct fpga_device *priv = dev_get_drvdata(dev); - unsigned long enable; - int ret; - - ret = kstrtoul(buf, 0, &enable); - if (ret) { - dev_err(priv->dev, "unable to parse enable input\n"); - return ret; - } - - /* protect against concurrent enable/disable */ - ret = mutex_lock_interruptible(&priv->mutex); - if (ret) - return ret; - - if (enable) - ret = data_device_enable(priv); - else - ret = data_device_disable(priv); - - if (ret) { - dev_err(priv->dev, "device %s failed\n", - enable ? "enable" : "disable"); - count = ret; - goto out_unlock; - } - -out_unlock: - mutex_unlock(&priv->mutex); - return count; -} - -static DEVICE_ATTR(enable, S_IWUSR | S_IRUGO, data_en_show, data_en_set); - -static struct attribute *data_sysfs_attrs[] = { - &dev_attr_enable.attr, - NULL, -}; - -static const struct attribute_group rt_sysfs_attr_group = { - .attrs = data_sysfs_attrs, -}; - -/* - * FPGA Realtime Data Character Device - */ - -static int data_open(struct inode *inode, struct file *filp) -{ - /* - * The miscdevice layer puts our struct miscdevice into the - * filp->private_data field. We use this to find our private - * data and then overwrite it with our own private structure. - */ - struct fpga_device *priv = container_of(filp->private_data, - struct fpga_device, miscdev); - struct fpga_reader *reader; - int ret; - - /* allocate private data */ - reader = kzalloc(sizeof(*reader), GFP_KERNEL); - if (!reader) - return -ENOMEM; - - reader->priv = priv; - reader->buf = NULL; - - filp->private_data = reader; - ret = nonseekable_open(inode, filp); - if (ret) { - dev_err(priv->dev, "nonseekable-open failed\n"); - kfree(reader); - return ret; - } - - /* - * success, increase the reference count of the private data structure - * so that it doesn't disappear if the device is unbound - */ - kref_get(&priv->ref); - return 0; -} - -static int data_release(struct inode *inode, struct file *filp) -{ - struct fpga_reader *reader = filp->private_data; - struct fpga_device *priv = reader->priv; - - /* free the per-reader structure */ - data_free_buffer(reader->buf); - kfree(reader); - filp->private_data = NULL; - - /* decrement our reference count to the private data */ - kref_put(&priv->ref, fpga_device_release); - return 0; -} - -static ssize_t data_read(struct file *filp, char __user *ubuf, size_t count, - loff_t *f_pos) -{ - struct fpga_reader *reader = filp->private_data; - struct fpga_device *priv = reader->priv; - struct list_head *used = &priv->used; - bool drop_buffer = false; - struct data_buf *dbuf; - size_t avail; - void *data; - int ret; - - /* check if we already have a partial buffer */ - if (reader->buf) { - dbuf = reader->buf; - goto have_buffer; - } - - spin_lock_irq(&priv->lock); - - /* Block until there is at least one buffer on the used list */ - while (list_empty(used)) { - spin_unlock_irq(&priv->lock); - - if (filp->f_flags & O_NONBLOCK) - return -EAGAIN; - - ret = wait_event_interruptible(priv->wait, !list_empty(used)); - if (ret) - return ret; - - spin_lock_irq(&priv->lock); - } - - /* Grab the first buffer off of the used list */ - dbuf = list_first_entry(used, struct data_buf, entry); - list_del_init(&dbuf->entry); - - spin_unlock_irq(&priv->lock); - - /* Buffers are always mapped: unmap it */ - carma_dma_unmap(priv->dev, dbuf); - - /* save the buffer for later */ - reader->buf = dbuf; - reader->buf_start = 0; - -have_buffer: - /* Get the number of bytes available */ - avail = dbuf->size - reader->buf_start; - data = dbuf->vaddr + reader->buf_start; - - /* Get the number of bytes we can transfer */ - count = min(count, avail); - - /* Copy the data to the userspace buffer */ - if (copy_to_user(ubuf, data, count)) - return -EFAULT; - - /* Update the amount of available space */ - avail -= count; - - /* - * If there is still some data available, save the buffer for the - * next userspace call to read() and return - */ - if (avail > 0) { - reader->buf_start += count; - reader->buf = dbuf; - return count; - } - - /* - * Get the buffer ready to be reused for DMA - * - * If it fails, we pretend that the read never happed and return - * -EFAULT to userspace. The read will be retried. - */ - ret = carma_dma_map(priv->dev, dbuf); - if (ret) { - dev_err(priv->dev, "unable to remap buffer for DMA\n"); - return -EFAULT; - } - - /* Lock against concurrent enable/disable */ - spin_lock_irq(&priv->lock); - - /* the reader is finished with this buffer */ - reader->buf = NULL; - - /* - * One of two things has happened, the device is disabled, or the - * device has been reconfigured underneath us. In either case, we - * should just throw away the buffer. - * - * Lockdep complains if this is done under the spinlock, so we - * handle it during the unlock path. - */ - if (!priv->enabled || dbuf->size != priv->bufsize) { - drop_buffer = true; - goto out_unlock; - } - - /* The buffer is safe to reuse, so add it back to the free list */ - list_add_tail(&dbuf->entry, &priv->free); - -out_unlock: - spin_unlock_irq(&priv->lock); - - if (drop_buffer) { - carma_dma_unmap(priv->dev, dbuf); - data_free_buffer(dbuf); - } - - return count; -} - -static unsigned int data_poll(struct file *filp, struct poll_table_struct *tbl) -{ - struct fpga_reader *reader = filp->private_data; - struct fpga_device *priv = reader->priv; - unsigned int mask = 0; - - poll_wait(filp, &priv->wait, tbl); - - if (!list_empty(&priv->used)) - mask |= POLLIN | POLLRDNORM; - - return mask; -} - -static int data_mmap(struct file *filp, struct vm_area_struct *vma) -{ - struct fpga_reader *reader = filp->private_data; - struct fpga_device *priv = reader->priv; - unsigned long offset, vsize, psize, addr; - - /* VMA properties */ - offset = vma->vm_pgoff << PAGE_SHIFT; - vsize = vma->vm_end - vma->vm_start; - psize = priv->phys_size - offset; - addr = (priv->phys_addr + offset) >> PAGE_SHIFT; - - /* Check against the FPGA region's physical memory size */ - if (vsize > psize) { - dev_err(priv->dev, "requested mmap mapping too large\n"); - return -EINVAL; - } - - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - - return io_remap_pfn_range(vma, vma->vm_start, addr, vsize, - vma->vm_page_prot); -} - -static const struct file_operations data_fops = { - .owner = THIS_MODULE, - .open = data_open, - .release = data_release, - .read = data_read, - .poll = data_poll, - .mmap = data_mmap, - .llseek = no_llseek, -}; - -/* - * OpenFirmware Device Subsystem - */ - -static bool dma_filter(struct dma_chan *chan, void *data) -{ - /* - * DMA Channel #0 is used for the FPGA Programmer, so ignore it - * - * This probably won't survive an unload/load cycle of the Freescale - * DMAEngine driver, but that won't be a problem - */ - if (chan->chan_id == 0 && chan->device->dev_id == 0) - return false; - - return true; -} - -static int data_of_probe(struct platform_device *op) -{ - struct device_node *of_node = op->dev.of_node; - struct device *this_device; - struct fpga_device *priv; - struct resource res; - dma_cap_mask_t mask; - int ret; - - /* Allocate private data */ - priv = kzalloc(sizeof(*priv), GFP_KERNEL); - if (!priv) { - dev_err(&op->dev, "Unable to allocate device private data\n"); - ret = -ENOMEM; - goto out_return; - } - - platform_set_drvdata(op, priv); - priv->dev = &op->dev; - kref_init(&priv->ref); - mutex_init(&priv->mutex); - - dev_set_drvdata(priv->dev, priv); - spin_lock_init(&priv->lock); - INIT_LIST_HEAD(&priv->free); - INIT_LIST_HEAD(&priv->used); - init_waitqueue_head(&priv->wait); - - /* Setup the misc device */ - priv->miscdev.minor = MISC_DYNAMIC_MINOR; - priv->miscdev.name = drv_name; - priv->miscdev.fops = &data_fops; - - /* Get the physical address of the FPGA registers */ - ret = of_address_to_resource(of_node, 0, &res); - if (ret) { - dev_err(&op->dev, "Unable to find FPGA physical address\n"); - ret = -ENODEV; - goto out_free_priv; - } - - priv->phys_addr = res.start; - priv->phys_size = resource_size(&res); - - /* ioremap the registers for use */ - priv->regs = of_iomap(of_node, 0); - if (!priv->regs) { - dev_err(&op->dev, "Unable to ioremap registers\n"); - ret = -ENOMEM; - goto out_free_priv; - } - - dma_cap_zero(mask); - dma_cap_set(DMA_MEMCPY, mask); - dma_cap_set(DMA_INTERRUPT, mask); - dma_cap_set(DMA_SLAVE, mask); - dma_cap_set(DMA_SG, mask); - - /* Request a DMA channel */ - priv->chan = dma_request_channel(mask, dma_filter, NULL); - if (!priv->chan) { - dev_err(&op->dev, "Unable to request DMA channel\n"); - ret = -ENODEV; - goto out_unmap_regs; - } - - /* Find the correct IRQ number */ - priv->irq = irq_of_parse_and_map(of_node, 0); - if (priv->irq == NO_IRQ) { - dev_err(&op->dev, "Unable to find IRQ line\n"); - ret = -ENODEV; - goto out_release_dma; - } - - /* Drive the GPIO for FPGA IRQ high (no interrupt) */ - iowrite32be(IRQ_CORL_DONE, priv->regs + SYS_IRQ_OUTPUT_DATA); - - /* Register the miscdevice */ - ret = misc_register(&priv->miscdev); - if (ret) { - dev_err(&op->dev, "Unable to register miscdevice\n"); - goto out_irq_dispose_mapping; - } - - /* Create the debugfs files */ - ret = data_debugfs_init(priv); - if (ret) { - dev_err(&op->dev, "Unable to create debugfs files\n"); - goto out_misc_deregister; - } - - /* Create the sysfs files */ - this_device = priv->miscdev.this_device; - dev_set_drvdata(this_device, priv); - ret = sysfs_create_group(&this_device->kobj, &rt_sysfs_attr_group); - if (ret) { - dev_err(&op->dev, "Unable to create sysfs files\n"); - goto out_data_debugfs_exit; - } - - dev_info(&op->dev, "CARMA FPGA Realtime Data Driver Loaded\n"); - return 0; - -out_data_debugfs_exit: - data_debugfs_exit(priv); -out_misc_deregister: - misc_deregister(&priv->miscdev); -out_irq_dispose_mapping: - irq_dispose_mapping(priv->irq); -out_release_dma: - dma_release_channel(priv->chan); -out_unmap_regs: - iounmap(priv->regs); -out_free_priv: - kref_put(&priv->ref, fpga_device_release); -out_return: - return ret; -} - -static int data_of_remove(struct platform_device *op) -{ - struct fpga_device *priv = platform_get_drvdata(op); - struct device *this_device = priv->miscdev.this_device; - - /* remove all sysfs files, now the device cannot be re-enabled */ - sysfs_remove_group(&this_device->kobj, &rt_sysfs_attr_group); - - /* remove all debugfs files */ - data_debugfs_exit(priv); - - /* disable the device from generating data */ - data_device_disable(priv); - - /* remove the character device to stop new readers from appearing */ - misc_deregister(&priv->miscdev); - - /* cleanup everything not needed by readers */ - irq_dispose_mapping(priv->irq); - dma_release_channel(priv->chan); - iounmap(priv->regs); - - /* release our reference */ - kref_put(&priv->ref, fpga_device_release); - return 0; -} - -static const struct of_device_id data_of_match[] = { - { .compatible = "carma,carma-fpga", }, - {}, -}; - -static struct platform_driver data_of_driver = { - .probe = data_of_probe, - .remove = data_of_remove, - .driver = { - .name = drv_name, - .of_match_table = data_of_match, - }, -}; - -module_platform_driver(data_of_driver); - -MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); -MODULE_DESCRIPTION("CARMA DATA-FPGA Access Driver"); -MODULE_LICENSE("GPL"); |