1/*
2 * CARMA Board DATA-FPGA Programmer
3 *
4 * Copyright (c) 2009-2011 Ira W. Snyder <iws@ovro.caltech.edu>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 */
11
12#include <linux/dma-mapping.h>
13#include <linux/of_platform.h>
14#include <linux/completion.h>
15#include <linux/miscdevice.h>
16#include <linux/dmaengine.h>
17#include <linux/interrupt.h>
18#include <linux/highmem.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/mutex.h>
22#include <linux/delay.h>
23#include <linux/init.h>
24#include <linux/leds.h>
25#include <linux/slab.h>
26#include <linux/kref.h>
27#include <linux/fs.h>
28#include <linux/io.h>
29
30#include <media/videobuf-dma-sg.h>
31
32/* MPC8349EMDS specific get_immrbase() */
33#include <sysdev/fsl_soc.h>
34
35static const char drv_name[] = "carma-fpga-program";
36
37/*
38 * Firmware images are always this exact size
39 *
40 * 12849552 bytes for a CARMA Digitizer Board (EP2S90 FPGAs)
41 * 18662880 bytes for a CARMA Correlator Board (EP2S130 FPGAs)
42 */
43#define FW_SIZE_EP2S90		12849552
44#define FW_SIZE_EP2S130		18662880
45
46struct fpga_dev {
47	struct miscdevice miscdev;
48
49	/* Reference count */
50	struct kref ref;
51
52	/* Device Registers */
53	struct device *dev;
54	void __iomem *regs;
55	void __iomem *immr;
56
57	/* Freescale DMA Device */
58	struct dma_chan *chan;
59
60	/* Interrupts */
61	int irq, status;
62	struct completion completion;
63
64	/* FPGA Bitfile */
65	struct mutex lock;
66
67	struct videobuf_dmabuf vb;
68	bool vb_allocated;
69
70	/* max size and written bytes */
71	size_t fw_size;
72	size_t bytes;
73};
74
75/*
76 * FPGA Bitfile Helpers
77 */
78
79/**
80 * fpga_drop_firmware_data() - drop the bitfile image from memory
81 * @priv: the driver's private data structure
82 *
83 * LOCKING: must hold priv->lock
84 */
85static void fpga_drop_firmware_data(struct fpga_dev *priv)
86{
87	videobuf_dma_free(&priv->vb);
88	priv->vb_allocated = false;
89	priv->bytes = 0;
90}
91
92/*
93 * Private Data Reference Count
94 */
95
96static void fpga_dev_remove(struct kref *ref)
97{
98	struct fpga_dev *priv = container_of(ref, struct fpga_dev, ref);
99
100	/* free any firmware image that was not programmed */
101	fpga_drop_firmware_data(priv);
102
103	mutex_destroy(&priv->lock);
104	kfree(priv);
105}
106
107/*
108 * LED Trigger (could be a seperate module)
109 */
110
111/*
112 * NOTE: this whole thing does have the problem that whenever the led's are
113 * NOTE: first set to use the fpga trigger, they could be in the wrong state
114 */
115
116DEFINE_LED_TRIGGER(ledtrig_fpga);
117
118static void ledtrig_fpga_programmed(bool enabled)
119{
120	if (enabled)
121		led_trigger_event(ledtrig_fpga, LED_FULL);
122	else
123		led_trigger_event(ledtrig_fpga, LED_OFF);
124}
125
126/*
127 * FPGA Register Helpers
128 */
129
130/* Register Definitions */
131#define FPGA_CONFIG_CONTROL		0x40
132#define FPGA_CONFIG_STATUS		0x44
133#define FPGA_CONFIG_FIFO_SIZE		0x48
134#define FPGA_CONFIG_FIFO_USED		0x4C
135#define FPGA_CONFIG_TOTAL_BYTE_COUNT	0x50
136#define FPGA_CONFIG_CUR_BYTE_COUNT	0x54
137
138#define FPGA_FIFO_ADDRESS		0x3000
139
140static int fpga_fifo_size(void __iomem *regs)
141{
142	return ioread32be(regs + FPGA_CONFIG_FIFO_SIZE);
143}
144
145#define CFG_STATUS_ERR_MASK	0xfffe
146
147static int fpga_config_error(void __iomem *regs)
148{
149	return ioread32be(regs + FPGA_CONFIG_STATUS) & CFG_STATUS_ERR_MASK;
150}
151
152static int fpga_fifo_empty(void __iomem *regs)
153{
154	return ioread32be(regs + FPGA_CONFIG_FIFO_USED) == 0;
155}
156
157static void fpga_fifo_write(void __iomem *regs, u32 val)
158{
159	iowrite32be(val, regs + FPGA_FIFO_ADDRESS);
160}
161
162static void fpga_set_byte_count(void __iomem *regs, u32 count)
163{
164	iowrite32be(count, regs + FPGA_CONFIG_TOTAL_BYTE_COUNT);
165}
166
167#define CFG_CTL_ENABLE	(1 << 0)
168#define CFG_CTL_RESET	(1 << 1)
169#define CFG_CTL_DMA	(1 << 2)
170
171static void fpga_programmer_enable(struct fpga_dev *priv, bool dma)
172{
173	u32 val;
174
175	val = (dma) ? (CFG_CTL_ENABLE | CFG_CTL_DMA) : CFG_CTL_ENABLE;
176	iowrite32be(val, priv->regs + FPGA_CONFIG_CONTROL);
177}
178
179static void fpga_programmer_disable(struct fpga_dev *priv)
180{
181	iowrite32be(0x0, priv->regs + FPGA_CONFIG_CONTROL);
182}
183
184static void fpga_dump_registers(struct fpga_dev *priv)
185{
186	u32 control, status, size, used, total, curr;
187
188	/* good status: do nothing */
189	if (priv->status == 0)
190		return;
191
192	/* Dump all status registers */
193	control = ioread32be(priv->regs + FPGA_CONFIG_CONTROL);
194	status = ioread32be(priv->regs + FPGA_CONFIG_STATUS);
195	size = ioread32be(priv->regs + FPGA_CONFIG_FIFO_SIZE);
196	used = ioread32be(priv->regs + FPGA_CONFIG_FIFO_USED);
197	total = ioread32be(priv->regs + FPGA_CONFIG_TOTAL_BYTE_COUNT);
198	curr = ioread32be(priv->regs + FPGA_CONFIG_CUR_BYTE_COUNT);
199
200	dev_err(priv->dev, "Configuration failed, dumping status registers\n");
201	dev_err(priv->dev, "Control:    0x%.8x\n", control);
202	dev_err(priv->dev, "Status:     0x%.8x\n", status);
203	dev_err(priv->dev, "FIFO Size:  0x%.8x\n", size);
204	dev_err(priv->dev, "FIFO Used:  0x%.8x\n", used);
205	dev_err(priv->dev, "FIFO Total: 0x%.8x\n", total);
206	dev_err(priv->dev, "FIFO Curr:  0x%.8x\n", curr);
207}
208
209/*
210 * FPGA Power Supply Code
211 */
212
213#define CTL_PWR_CONTROL		0x2006
214#define CTL_PWR_STATUS		0x200A
215#define CTL_PWR_FAIL		0x200B
216
217#define PWR_CONTROL_ENABLE	0x01
218
219#define PWR_STATUS_ERROR_MASK	0x10
220#define PWR_STATUS_GOOD		0x0f
221
222/*
223 * Determine if the FPGA power is good for all supplies
224 */
225static bool fpga_power_good(struct fpga_dev *priv)
226{
227	u8 val;
228
229	val = ioread8(priv->regs + CTL_PWR_STATUS);
230	if (val & PWR_STATUS_ERROR_MASK)
231		return false;
232
233	return val == PWR_STATUS_GOOD;
234}
235
236/*
237 * Disable the FPGA power supplies
238 */
239static void fpga_disable_power_supplies(struct fpga_dev *priv)
240{
241	unsigned long start;
242	u8 val;
243
244	iowrite8(0x0, priv->regs + CTL_PWR_CONTROL);
245
246	/*
247	 * Wait 500ms for the power rails to discharge
248	 *
249	 * Without this delay, the CTL-CPLD state machine can get into a
250	 * state where it is waiting for the power-goods to assert, but they
251	 * never do. This only happens when enabling and disabling the
252	 * power sequencer very rapidly.
253	 *
254	 * The loop below will also wait for the power goods to de-assert,
255	 * but testing has shown that they are always disabled by the time
256	 * the sleep completes. However, omitting the sleep and only waiting
257	 * for the power-goods to de-assert was not sufficient to ensure
258	 * that the power sequencer would not wedge itself.
259	 */
260	msleep(500);
261
262	start = jiffies;
263	while (time_before(jiffies, start + HZ)) {
264		val = ioread8(priv->regs + CTL_PWR_STATUS);
265		if (!(val & PWR_STATUS_GOOD))
266			break;
267
268		usleep_range(5000, 10000);
269	}
270
271	val = ioread8(priv->regs + CTL_PWR_STATUS);
272	if (val & PWR_STATUS_GOOD) {
273		dev_err(priv->dev, "power disable failed: "
274				   "power goods: status 0x%.2x\n", val);
275	}
276
277	if (val & PWR_STATUS_ERROR_MASK) {
278		dev_err(priv->dev, "power disable failed: "
279				   "alarm bit set: status 0x%.2x\n", val);
280	}
281}
282
283/**
284 * fpga_enable_power_supplies() - enable the DATA-FPGA power supplies
285 * @priv: the driver's private data structure
286 *
287 * Enable the DATA-FPGA power supplies, waiting up to 1 second for
288 * them to enable successfully.
289 *
290 * Returns 0 on success, -ERRNO otherwise
291 */
292static int fpga_enable_power_supplies(struct fpga_dev *priv)
293{
294	unsigned long start = jiffies;
295
296	if (fpga_power_good(priv)) {
297		dev_dbg(priv->dev, "power was already good\n");
298		return 0;
299	}
300
301	iowrite8(PWR_CONTROL_ENABLE, priv->regs + CTL_PWR_CONTROL);
302	while (time_before(jiffies, start + HZ)) {
303		if (fpga_power_good(priv))
304			return 0;
305
306		usleep_range(5000, 10000);
307	}
308
309	return fpga_power_good(priv) ? 0 : -ETIMEDOUT;
310}
311
312/*
313 * Determine if the FPGA power supplies are all enabled
314 */
315static bool fpga_power_enabled(struct fpga_dev *priv)
316{
317	u8 val;
318
319	val = ioread8(priv->regs + CTL_PWR_CONTROL);
320	if (val & PWR_CONTROL_ENABLE)
321		return true;
322
323	return false;
324}
325
326/*
327 * Determine if the FPGA's are programmed and running correctly
328 */
329static bool fpga_running(struct fpga_dev *priv)
330{
331	if (!fpga_power_good(priv))
332		return false;
333
334	/* Check the config done bit */
335	return ioread32be(priv->regs + FPGA_CONFIG_STATUS) & (1 << 18);
336}
337
338/*
339 * FPGA Programming Code
340 */
341
342/**
343 * fpga_program_block() - put a block of data into the programmer's FIFO
344 * @priv: the driver's private data structure
345 * @buf: the data to program
346 * @count: the length of data to program (must be a multiple of 4 bytes)
347 *
348 * Returns 0 on success, -ERRNO otherwise
349 */
350static int fpga_program_block(struct fpga_dev *priv, void *buf, size_t count)
351{
352	u32 *data = buf;
353	int size = fpga_fifo_size(priv->regs);
354	int i, len;
355	unsigned long timeout;
356
357	/* enforce correct data length for the FIFO */
358	BUG_ON(count % 4 != 0);
359
360	while (count > 0) {
361
362		/* Get the size of the block to write (maximum is FIFO_SIZE) */
363		len = min_t(size_t, count, size);
364		timeout = jiffies + HZ / 4;
365
366		/* Write the block */
367		for (i = 0; i < len / 4; i++)
368			fpga_fifo_write(priv->regs, data[i]);
369
370		/* Update the amounts left */
371		count -= len;
372		data += len / 4;
373
374		/* Wait for the fifo to empty */
375		while (true) {
376
377			if (fpga_fifo_empty(priv->regs)) {
378				break;
379			} else {
380				dev_dbg(priv->dev, "Fifo not empty\n");
381				cpu_relax();
382			}
383
384			if (fpga_config_error(priv->regs)) {
385				dev_err(priv->dev, "Error detected\n");
386				return -EIO;
387			}
388
389			if (time_after(jiffies, timeout)) {
390				dev_err(priv->dev, "Fifo drain timeout\n");
391				return -ETIMEDOUT;
392			}
393
394			usleep_range(5000, 10000);
395		}
396	}
397
398	return 0;
399}
400
401/**
402 * fpga_program_cpu() - program the DATA-FPGA's using the CPU
403 * @priv: the driver's private data structure
404 *
405 * This is useful when the DMA programming method fails. It is possible to
406 * wedge the Freescale DMA controller such that the DMA programming method
407 * always fails. This method has always succeeded.
408 *
409 * Returns 0 on success, -ERRNO otherwise
410 */
411static noinline int fpga_program_cpu(struct fpga_dev *priv)
412{
413	int ret;
414
415	/* Disable the programmer */
416	fpga_programmer_disable(priv);
417
418	/* Set the total byte count */
419	fpga_set_byte_count(priv->regs, priv->bytes);
420	dev_dbg(priv->dev, "total byte count %u bytes\n", priv->bytes);
421
422	/* Enable the controller for programming */
423	fpga_programmer_enable(priv, false);
424	dev_dbg(priv->dev, "enabled the controller\n");
425
426	/* Write each chunk of the FPGA bitfile to FPGA programmer */
427	ret = fpga_program_block(priv, priv->vb.vaddr, priv->bytes);
428	if (ret)
429		goto out_disable_controller;
430
431	/* Wait for the interrupt handler to signal that programming finished */
432	ret = wait_for_completion_timeout(&priv->completion, 2 * HZ);
433	if (!ret) {
434		dev_err(priv->dev, "Timed out waiting for completion\n");
435		ret = -ETIMEDOUT;
436		goto out_disable_controller;
437	}
438
439	/* Retrieve the status from the interrupt handler */
440	ret = priv->status;
441
442out_disable_controller:
443	fpga_programmer_disable(priv);
444	return ret;
445}
446
447#define FIFO_DMA_ADDRESS	0xf0003000
448#define FIFO_MAX_LEN		4096
449
450/**
451 * fpga_program_dma() - program the DATA-FPGA's using the DMA engine
452 * @priv: the driver's private data structure
453 *
454 * Program the DATA-FPGA's using the Freescale DMA engine. This requires that
455 * the engine is programmed such that the hardware DMA request lines can
456 * control the entire DMA transaction. The system controller FPGA then
457 * completely offloads the programming from the CPU.
458 *
459 * Returns 0 on success, -ERRNO otherwise
460 */
461static noinline int fpga_program_dma(struct fpga_dev *priv)
462{
463	struct videobuf_dmabuf *vb = &priv->vb;
464	struct dma_chan *chan = priv->chan;
465	struct dma_async_tx_descriptor *tx;
466	size_t num_pages, len, avail = 0;
467	struct dma_slave_config config;
468	struct scatterlist *sg;
469	struct sg_table table;
470	dma_cookie_t cookie;
471	int ret, i;
472
473	/* Disable the programmer */
474	fpga_programmer_disable(priv);
475
476	/* Allocate a scatterlist for the DMA destination */
477	num_pages = DIV_ROUND_UP(priv->bytes, FIFO_MAX_LEN);
478	ret = sg_alloc_table(&table, num_pages, GFP_KERNEL);
479	if (ret) {
480		dev_err(priv->dev, "Unable to allocate dst scatterlist\n");
481		ret = -ENOMEM;
482		goto out_return;
483	}
484
485	/*
486	 * This is an ugly hack
487	 *
488	 * We fill in a scatterlist as if it were mapped for DMA. This is
489	 * necessary because there exists no better structure for this
490	 * inside the kernel code.
491	 *
492	 * As an added bonus, we can use the DMAEngine API for all of this,
493	 * rather than inventing another extremely similar API.
494	 */
495	avail = priv->bytes;
496	for_each_sg(table.sgl, sg, num_pages, i) {
497		len = min_t(size_t, avail, FIFO_MAX_LEN);
498		sg_dma_address(sg) = FIFO_DMA_ADDRESS;
499		sg_dma_len(sg) = len;
500
501		avail -= len;
502	}
503
504	/* Map the buffer for DMA */
505	ret = videobuf_dma_map(priv->dev, &priv->vb);
506	if (ret) {
507		dev_err(priv->dev, "Unable to map buffer for DMA\n");
508		goto out_free_table;
509	}
510
511	/*
512	 * Configure the DMA channel to transfer FIFO_SIZE / 2 bytes per
513	 * transaction, and then put it under external control
514	 */
515	memset(&config, 0, sizeof(config));
516	config.direction = DMA_MEM_TO_DEV;
517	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
518	config.dst_maxburst = fpga_fifo_size(priv->regs) / 2 / 4;
519	ret = chan->device->device_control(chan, DMA_SLAVE_CONFIG,
520					   (unsigned long)&config);
521	if (ret) {
522		dev_err(priv->dev, "DMA slave configuration failed\n");
523		goto out_dma_unmap;
524	}
525
526	ret = chan->device->device_control(chan, FSLDMA_EXTERNAL_START, 1);
527	if (ret) {
528		dev_err(priv->dev, "DMA external control setup failed\n");
529		goto out_dma_unmap;
530	}
531
532	/* setup and submit the DMA transaction */
533	tx = chan->device->device_prep_dma_sg(chan,
534					      table.sgl, num_pages,
535					      vb->sglist, vb->sglen, 0);
536	if (!tx) {
537		dev_err(priv->dev, "Unable to prep DMA transaction\n");
538		ret = -ENOMEM;
539		goto out_dma_unmap;
540	}
541
542	cookie = tx->tx_submit(tx);
543	if (dma_submit_error(cookie)) {
544		dev_err(priv->dev, "Unable to submit DMA transaction\n");
545		ret = -ENOMEM;
546		goto out_dma_unmap;
547	}
548
549	dma_async_memcpy_issue_pending(chan);
550
551	/* Set the total byte count */
552	fpga_set_byte_count(priv->regs, priv->bytes);
553	dev_dbg(priv->dev, "total byte count %u bytes\n", priv->bytes);
554
555	/* Enable the controller for DMA programming */
556	fpga_programmer_enable(priv, true);
557	dev_dbg(priv->dev, "enabled the controller\n");
558
559	/* Wait for the interrupt handler to signal that programming finished */
560	ret = wait_for_completion_timeout(&priv->completion, 2 * HZ);
561	if (!ret) {
562		dev_err(priv->dev, "Timed out waiting for completion\n");
563		ret = -ETIMEDOUT;
564		goto out_disable_controller;
565	}
566
567	/* Retrieve the status from the interrupt handler */
568	ret = priv->status;
569
570out_disable_controller:
571	fpga_programmer_disable(priv);
572out_dma_unmap:
573	videobuf_dma_unmap(priv->dev, vb);
574out_free_table:
575	sg_free_table(&table);
576out_return:
577	return ret;
578}
579
580/*
581 * Interrupt Handling
582 */
583
584static irqreturn_t fpga_irq(int irq, void *dev_id)
585{
586	struct fpga_dev *priv = dev_id;
587
588	/* Save the status */
589	priv->status = fpga_config_error(priv->regs) ? -EIO : 0;
590	dev_dbg(priv->dev, "INTERRUPT status %d\n", priv->status);
591	fpga_dump_registers(priv);
592
593	/* Disabling the programmer clears the interrupt */
594	fpga_programmer_disable(priv);
595
596	/* Notify any waiters */
597	complete(&priv->completion);
598
599	return IRQ_HANDLED;
600}
601
602/*
603 * SYSFS Helpers
604 */
605
606/**
607 * fpga_do_stop() - deconfigure (reset) the DATA-FPGA's
608 * @priv: the driver's private data structure
609 *
610 * LOCKING: must hold priv->lock
611 */
612static int fpga_do_stop(struct fpga_dev *priv)
613{
614	u32 val;
615
616	/* Set the led to unprogrammed */
617	ledtrig_fpga_programmed(false);
618
619	/* Pulse the config line to reset the FPGA's */
620	val = CFG_CTL_ENABLE | CFG_CTL_RESET;
621	iowrite32be(val, priv->regs + FPGA_CONFIG_CONTROL);
622	iowrite32be(0x0, priv->regs + FPGA_CONFIG_CONTROL);
623
624	return 0;
625}
626
627static noinline int fpga_do_program(struct fpga_dev *priv)
628{
629	int ret;
630
631	if (priv->bytes != priv->fw_size) {
632		dev_err(priv->dev, "Incorrect bitfile size: got %zu bytes, "
633				   "should be %zu bytes\n",
634				   priv->bytes, priv->fw_size);
635		return -EINVAL;
636	}
637
638	if (!fpga_power_enabled(priv)) {
639		dev_err(priv->dev, "Power not enabled\n");
640		return -EINVAL;
641	}
642
643	if (!fpga_power_good(priv)) {
644		dev_err(priv->dev, "Power not good\n");
645		return -EINVAL;
646	}
647
648	/* Set the LED to unprogrammed */
649	ledtrig_fpga_programmed(false);
650
651	/* Try to program the FPGA's using DMA */
652	ret = fpga_program_dma(priv);
653
654	/* If DMA failed or doesn't exist, try with CPU */
655	if (ret) {
656		dev_warn(priv->dev, "Falling back to CPU programming\n");
657		ret = fpga_program_cpu(priv);
658	}
659
660	if (ret) {
661		dev_err(priv->dev, "Unable to program FPGA's\n");
662		return ret;
663	}
664
665	/* Drop the firmware bitfile from memory */
666	fpga_drop_firmware_data(priv);
667
668	dev_dbg(priv->dev, "FPGA programming successful\n");
669	ledtrig_fpga_programmed(true);
670
671	return 0;
672}
673
674/*
675 * File Operations
676 */
677
678static int fpga_open(struct inode *inode, struct file *filp)
679{
680	/*
681	 * The miscdevice layer puts our struct miscdevice into the
682	 * filp->private_data field. We use this to find our private
683	 * data and then overwrite it with our own private structure.
684	 */
685	struct fpga_dev *priv = container_of(filp->private_data,
686					     struct fpga_dev, miscdev);
687	unsigned int nr_pages;
688	int ret;
689
690	/* We only allow one process at a time */
691	ret = mutex_lock_interruptible(&priv->lock);
692	if (ret)
693		return ret;
694
695	filp->private_data = priv;
696	kref_get(&priv->ref);
697
698	/* Truncation: drop any existing data */
699	if (filp->f_flags & O_TRUNC)
700		priv->bytes = 0;
701
702	/* Check if we have already allocated a buffer */
703	if (priv->vb_allocated)
704		return 0;
705
706	/* Allocate a buffer to hold enough data for the bitfile */
707	nr_pages = DIV_ROUND_UP(priv->fw_size, PAGE_SIZE);
708	ret = videobuf_dma_init_kernel(&priv->vb, DMA_TO_DEVICE, nr_pages);
709	if (ret) {
710		dev_err(priv->dev, "unable to allocate data buffer\n");
711		mutex_unlock(&priv->lock);
712		kref_put(&priv->ref, fpga_dev_remove);
713		return ret;
714	}
715
716	priv->vb_allocated = true;
717	return 0;
718}
719
720static int fpga_release(struct inode *inode, struct file *filp)
721{
722	struct fpga_dev *priv = filp->private_data;
723
724	mutex_unlock(&priv->lock);
725	kref_put(&priv->ref, fpga_dev_remove);
726	return 0;
727}
728
729static ssize_t fpga_write(struct file *filp, const char __user *buf,
730			  size_t count, loff_t *f_pos)
731{
732	struct fpga_dev *priv = filp->private_data;
733
734	/* FPGA bitfiles have an exact size: disallow anything else */
735	if (priv->bytes >= priv->fw_size)
736		return -ENOSPC;
737
738	count = min_t(size_t, priv->fw_size - priv->bytes, count);
739	if (copy_from_user(priv->vb.vaddr + priv->bytes, buf, count))
740		return -EFAULT;
741
742	priv->bytes += count;
743	return count;
744}
745
746static ssize_t fpga_read(struct file *filp, char __user *buf, size_t count,
747			 loff_t *f_pos)
748{
749	struct fpga_dev *priv = filp->private_data;
750
751	count = min_t(size_t, priv->bytes - *f_pos, count);
752	if (copy_to_user(buf, priv->vb.vaddr + *f_pos, count))
753		return -EFAULT;
754
755	*f_pos += count;
756	return count;
757}
758
759static loff_t fpga_llseek(struct file *filp, loff_t offset, int origin)
760{
761	struct fpga_dev *priv = filp->private_data;
762	loff_t newpos;
763
764	/* only read-only opens are allowed to seek */
765	if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
766		return -EINVAL;
767
768	switch (origin) {
769	case SEEK_SET: /* seek relative to the beginning of the file */
770		newpos = offset;
771		break;
772	case SEEK_CUR: /* seek relative to current position in the file */
773		newpos = filp->f_pos + offset;
774		break;
775	case SEEK_END: /* seek relative to the end of the file */
776		newpos = priv->fw_size - offset;
777		break;
778	default:
779		return -EINVAL;
780	}
781
782	/* check for sanity */
783	if (newpos > priv->fw_size)
784		return -EINVAL;
785
786	filp->f_pos = newpos;
787	return newpos;
788}
789
790static const struct file_operations fpga_fops = {
791	.open		= fpga_open,
792	.release	= fpga_release,
793	.write		= fpga_write,
794	.read		= fpga_read,
795	.llseek		= fpga_llseek,
796};
797
798/*
799 * Device Attributes
800 */
801
802static ssize_t pfail_show(struct device *dev, struct device_attribute *attr,
803			  char *buf)
804{
805	struct fpga_dev *priv = dev_get_drvdata(dev);
806	u8 val;
807
808	val = ioread8(priv->regs + CTL_PWR_FAIL);
809	return snprintf(buf, PAGE_SIZE, "0x%.2x\n", val);
810}
811
812static ssize_t pgood_show(struct device *dev, struct device_attribute *attr,
813			  char *buf)
814{
815	struct fpga_dev *priv = dev_get_drvdata(dev);
816	return snprintf(buf, PAGE_SIZE, "%d\n", fpga_power_good(priv));
817}
818
819static ssize_t penable_show(struct device *dev, struct device_attribute *attr,
820			    char *buf)
821{
822	struct fpga_dev *priv = dev_get_drvdata(dev);
823	return snprintf(buf, PAGE_SIZE, "%d\n", fpga_power_enabled(priv));
824}
825
826static ssize_t penable_store(struct device *dev, struct device_attribute *attr,
827			     const char *buf, size_t count)
828{
829	struct fpga_dev *priv = dev_get_drvdata(dev);
830	unsigned long val;
831	int ret;
832
833	if (strict_strtoul(buf, 0, &val))
834		return -EINVAL;
835
836	if (val) {
837		ret = fpga_enable_power_supplies(priv);
838		if (ret)
839			return ret;
840	} else {
841		fpga_do_stop(priv);
842		fpga_disable_power_supplies(priv);
843	}
844
845	return count;
846}
847
848static ssize_t program_show(struct device *dev, struct device_attribute *attr,
849			    char *buf)
850{
851	struct fpga_dev *priv = dev_get_drvdata(dev);
852	return snprintf(buf, PAGE_SIZE, "%d\n", fpga_running(priv));
853}
854
855static ssize_t program_store(struct device *dev, struct device_attribute *attr,
856			     const char *buf, size_t count)
857{
858	struct fpga_dev *priv = dev_get_drvdata(dev);
859	unsigned long val;
860	int ret;
861
862	if (strict_strtoul(buf, 0, &val))
863		return -EINVAL;
864
865	/* We can't have an image writer and be programming simultaneously */
866	if (mutex_lock_interruptible(&priv->lock))
867		return -ERESTARTSYS;
868
869	/* Program or Reset the FPGA's */
870	ret = val ? fpga_do_program(priv) : fpga_do_stop(priv);
871	if (ret)
872		goto out_unlock;
873
874	/* Success */
875	ret = count;
876
877out_unlock:
878	mutex_unlock(&priv->lock);
879	return ret;
880}
881
882static DEVICE_ATTR(power_fail, S_IRUGO, pfail_show, NULL);
883static DEVICE_ATTR(power_good, S_IRUGO, pgood_show, NULL);
884static DEVICE_ATTR(power_enable, S_IRUGO | S_IWUSR,
885		   penable_show, penable_store);
886
887static DEVICE_ATTR(program, S_IRUGO | S_IWUSR,
888		   program_show, program_store);
889
890static struct attribute *fpga_attributes[] = {
891	&dev_attr_power_fail.attr,
892	&dev_attr_power_good.attr,
893	&dev_attr_power_enable.attr,
894	&dev_attr_program.attr,
895	NULL,
896};
897
898static const struct attribute_group fpga_attr_group = {
899	.attrs = fpga_attributes,
900};
901
902/*
903 * OpenFirmware Device Subsystem
904 */
905
906#define SYS_REG_VERSION		0x00
907#define SYS_REG_GEOGRAPHIC	0x10
908
909static bool dma_filter(struct dma_chan *chan, void *data)
910{
911	/*
912	 * DMA Channel #0 is the only acceptable device
913	 *
914	 * This probably won't survive an unload/load cycle of the Freescale
915	 * DMAEngine driver, but that won't be a problem
916	 */
917	return chan->chan_id == 0 && chan->device->dev_id == 0;
918}
919
920static int fpga_of_remove(struct platform_device *op)
921{
922	struct fpga_dev *priv = dev_get_drvdata(&op->dev);
923	struct device *this_device = priv->miscdev.this_device;
924
925	sysfs_remove_group(&this_device->kobj, &fpga_attr_group);
926	misc_deregister(&priv->miscdev);
927
928	free_irq(priv->irq, priv);
929	irq_dispose_mapping(priv->irq);
930
931	/* make sure the power supplies are off */
932	fpga_disable_power_supplies(priv);
933
934	/* unmap registers */
935	iounmap(priv->immr);
936	iounmap(priv->regs);
937
938	dma_release_channel(priv->chan);
939
940	/* drop our reference to the private data structure */
941	kref_put(&priv->ref, fpga_dev_remove);
942	return 0;
943}
944
945/* CTL-CPLD Version Register */
946#define CTL_CPLD_VERSION	0x2000
947
948static int fpga_of_probe(struct platform_device *op)
949{
950	struct device_node *of_node = op->dev.of_node;
951	struct device *this_device;
952	struct fpga_dev *priv;
953	dma_cap_mask_t mask;
954	u32 ver;
955	int ret;
956
957	/* Allocate private data */
958	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
959	if (!priv) {
960		dev_err(&op->dev, "Unable to allocate private data\n");
961		ret = -ENOMEM;
962		goto out_return;
963	}
964
965	/* Setup the miscdevice */
966	priv->miscdev.minor = MISC_DYNAMIC_MINOR;
967	priv->miscdev.name = drv_name;
968	priv->miscdev.fops = &fpga_fops;
969
970	kref_init(&priv->ref);
971
972	dev_set_drvdata(&op->dev, priv);
973	priv->dev = &op->dev;
974	mutex_init(&priv->lock);
975	init_completion(&priv->completion);
976	videobuf_dma_init(&priv->vb);
977
978	dev_set_drvdata(priv->dev, priv);
979	dma_cap_zero(mask);
980	dma_cap_set(DMA_MEMCPY, mask);
981	dma_cap_set(DMA_INTERRUPT, mask);
982	dma_cap_set(DMA_SLAVE, mask);
983	dma_cap_set(DMA_SG, mask);
984
985	/* Get control of DMA channel #0 */
986	priv->chan = dma_request_channel(mask, dma_filter, NULL);
987	if (!priv->chan) {
988		dev_err(&op->dev, "Unable to acquire DMA channel #0\n");
989		ret = -ENODEV;
990		goto out_free_priv;
991	}
992
993	/* Remap the registers for use */
994	priv->regs = of_iomap(of_node, 0);
995	if (!priv->regs) {
996		dev_err(&op->dev, "Unable to ioremap registers\n");
997		ret = -ENOMEM;
998		goto out_dma_release_channel;
999	}
1000
1001	/* Remap the IMMR for use */
1002	priv->immr = ioremap(get_immrbase(), 0x100000);
1003	if (!priv->immr) {
1004		dev_err(&op->dev, "Unable to ioremap IMMR\n");
1005		ret = -ENOMEM;
1006		goto out_unmap_regs;
1007	}
1008
1009	/*
1010	 * Check that external DMA is configured
1011	 *
1012	 * U-Boot does this for us, but we should check it and bail out if
1013	 * there is a problem. Failing to have this register setup correctly
1014	 * will cause the DMA controller to transfer a single cacheline
1015	 * worth of data, then wedge itself.
1016	 */
1017	if ((ioread32be(priv->immr + 0x114) & 0xE00) != 0xE00) {
1018		dev_err(&op->dev, "External DMA control not configured\n");
1019		ret = -ENODEV;
1020		goto out_unmap_immr;
1021	}
1022
1023	/*
1024	 * Check the CTL-CPLD version
1025	 *
1026	 * This driver uses the CTL-CPLD DATA-FPGA power sequencer, and we
1027	 * don't want to run on any version of the CTL-CPLD that does not use
1028	 * a compatible register layout.
1029	 *
1030	 * v2: changed register layout, added power sequencer
1031	 * v3: added glitch filter on the i2c overcurrent/overtemp outputs
1032	 */
1033	ver = ioread8(priv->regs + CTL_CPLD_VERSION);
1034	if (ver != 0x02 && ver != 0x03) {
1035		dev_err(&op->dev, "CTL-CPLD is not version 0x02 or 0x03!\n");
1036		ret = -ENODEV;
1037		goto out_unmap_immr;
1038	}
1039
1040	/* Set the exact size that the firmware image should be */
1041	ver = ioread32be(priv->regs + SYS_REG_VERSION);
1042	priv->fw_size = (ver & (1 << 18)) ? FW_SIZE_EP2S130 : FW_SIZE_EP2S90;
1043
1044	/* Find the correct IRQ number */
1045	priv->irq = irq_of_parse_and_map(of_node, 0);
1046	if (priv->irq == NO_IRQ) {
1047		dev_err(&op->dev, "Unable to find IRQ line\n");
1048		ret = -ENODEV;
1049		goto out_unmap_immr;
1050	}
1051
1052	/* Request the IRQ */
1053	ret = request_irq(priv->irq, fpga_irq, IRQF_SHARED, drv_name, priv);
1054	if (ret) {
1055		dev_err(&op->dev, "Unable to request IRQ %d\n", priv->irq);
1056		ret = -ENODEV;
1057		goto out_irq_dispose_mapping;
1058	}
1059
1060	/* Reset and stop the FPGA's, just in case */
1061	fpga_do_stop(priv);
1062
1063	/* Register the miscdevice */
1064	ret = misc_register(&priv->miscdev);
1065	if (ret) {
1066		dev_err(&op->dev, "Unable to register miscdevice\n");
1067		goto out_free_irq;
1068	}
1069
1070	/* Create the sysfs files */
1071	this_device = priv->miscdev.this_device;
1072	dev_set_drvdata(this_device, priv);
1073	ret = sysfs_create_group(&this_device->kobj, &fpga_attr_group);
1074	if (ret) {
1075		dev_err(&op->dev, "Unable to create sysfs files\n");
1076		goto out_misc_deregister;
1077	}
1078
1079	dev_info(priv->dev, "CARMA FPGA Programmer: %s rev%s with %s FPGAs\n",
1080			(ver & (1 << 17)) ? "Correlator" : "Digitizer",
1081			(ver & (1 << 16)) ? "B" : "A",
1082			(ver & (1 << 18)) ? "EP2S130" : "EP2S90");
1083
1084	return 0;
1085
1086out_misc_deregister:
1087	misc_deregister(&priv->miscdev);
1088out_free_irq:
1089	free_irq(priv->irq, priv);
1090out_irq_dispose_mapping:
1091	irq_dispose_mapping(priv->irq);
1092out_unmap_immr:
1093	iounmap(priv->immr);
1094out_unmap_regs:
1095	iounmap(priv->regs);
1096out_dma_release_channel:
1097	dma_release_channel(priv->chan);
1098out_free_priv:
1099	kref_put(&priv->ref, fpga_dev_remove);
1100out_return:
1101	return ret;
1102}
1103
1104static struct of_device_id fpga_of_match[] = {
1105	{ .compatible = "carma,fpga-programmer", },
1106	{},
1107};
1108
1109static struct platform_driver fpga_of_driver = {
1110	.probe		= fpga_of_probe,
1111	.remove		= fpga_of_remove,
1112	.driver		= {
1113		.name		= drv_name,
1114		.of_match_table	= fpga_of_match,
1115		.owner		= THIS_MODULE,
1116	},
1117};
1118
1119/*
1120 * Module Init / Exit
1121 */
1122
1123static int __init fpga_init(void)
1124{
1125	led_trigger_register_simple("fpga", &ledtrig_fpga);
1126	return platform_driver_register(&fpga_of_driver);
1127}
1128
1129static void __exit fpga_exit(void)
1130{
1131	platform_driver_unregister(&fpga_of_driver);
1132	led_trigger_unregister_simple(ledtrig_fpga);
1133}
1134
1135MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
1136MODULE_DESCRIPTION("CARMA Board DATA-FPGA Programmer");
1137MODULE_LICENSE("GPL");
1138
1139module_init(fpga_init);
1140module_exit(fpga_exit);
1141