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  1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
  3 * Copyright (C) 2012 Stephane Grosjean <s.grosjean@peak-system.com>
  4 *
  5 * Derived from the PCAN project file driver/src/pcan_pci.c:
  6 *
  7 * Copyright (C) 2001-2006  PEAK System-Technik GmbH
  8 */
  9
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/interrupt.h>
 13#include <linux/netdevice.h>
 14#include <linux/delay.h>
 15#include <linux/pci.h>
 16#include <linux/io.h>
 17#include <linux/can.h>
 18#include <linux/can/dev.h>
 19
 20#include "peak_canfd_user.h"
 21
 22MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
 23MODULE_DESCRIPTION("Socket-CAN driver for PEAK PCAN PCIe/M.2 FD family cards");
 24MODULE_LICENSE("GPL v2");
 25
 26#define PCIEFD_DRV_NAME		"peak_pciefd"
 27
 28#define PEAK_PCI_VENDOR_ID	0x001c	/* The PCI device and vendor IDs */
 29#define PEAK_PCIEFD_ID		0x0013	/* for PCIe slot cards */
 30#define PCAN_CPCIEFD_ID		0x0014	/* for Compact-PCI Serial slot cards */
 31#define PCAN_PCIE104FD_ID	0x0017	/* for PCIe-104 Express slot cards */
 32#define PCAN_MINIPCIEFD_ID      0x0018	/* for mini-PCIe slot cards */
 33#define PCAN_PCIEFD_OEM_ID      0x0019	/* for PCIe slot OEM cards */
 34#define PCAN_M2_ID		0x001a	/* for M2 slot cards */
 35
 36/* PEAK PCIe board access description */
 37#define PCIEFD_BAR0_SIZE		(64 * 1024)
 38#define PCIEFD_RX_DMA_SIZE		(4 * 1024)
 39#define PCIEFD_TX_DMA_SIZE		(4 * 1024)
 40
 41#define PCIEFD_TX_PAGE_SIZE		(2 * 1024)
 42
 43/* System Control Registers */
 44#define PCIEFD_REG_SYS_CTL_SET		0x0000	/* set bits */
 45#define PCIEFD_REG_SYS_CTL_CLR		0x0004	/* clear bits */
 46
 47/* Version info registers */
 48#define PCIEFD_REG_SYS_VER1		0x0040	/* version reg #1 */
 49#define PCIEFD_REG_SYS_VER2		0x0044	/* version reg #2 */
 50
 51#define PCIEFD_FW_VERSION(x, y, z)	(((u32)(x) << 24) | \
 52					 ((u32)(y) << 16) | \
 53					 ((u32)(z) << 8))
 54
 55/* System Control Registers Bits */
 56#define PCIEFD_SYS_CTL_TS_RST		0x00000001	/* timestamp clock */
 57#define PCIEFD_SYS_CTL_CLK_EN		0x00000002	/* system clock */
 58
 59/* CAN-FD channel addresses */
 60#define PCIEFD_CANX_OFF(c)		(((c) + 1) * 0x1000)
 61
 62#define PCIEFD_ECHO_SKB_MAX		PCANFD_ECHO_SKB_DEF
 63
 64/* CAN-FD channel registers */
 65#define PCIEFD_REG_CAN_MISC		0x0000	/* Misc. control */
 66#define PCIEFD_REG_CAN_CLK_SEL		0x0008	/* Clock selector */
 67#define PCIEFD_REG_CAN_CMD_PORT_L	0x0010	/* 64-bits command port */
 68#define PCIEFD_REG_CAN_CMD_PORT_H	0x0014
 69#define PCIEFD_REG_CAN_TX_REQ_ACC	0x0020	/* Tx request accumulator */
 70#define PCIEFD_REG_CAN_TX_CTL_SET	0x0030	/* Tx control set register */
 71#define PCIEFD_REG_CAN_TX_CTL_CLR	0x0038	/* Tx control clear register */
 72#define PCIEFD_REG_CAN_TX_DMA_ADDR_L	0x0040	/* 64-bits addr for Tx DMA */
 73#define PCIEFD_REG_CAN_TX_DMA_ADDR_H	0x0044
 74#define PCIEFD_REG_CAN_RX_CTL_SET	0x0050	/* Rx control set register */
 75#define PCIEFD_REG_CAN_RX_CTL_CLR	0x0058	/* Rx control clear register */
 76#define PCIEFD_REG_CAN_RX_CTL_WRT	0x0060	/* Rx control write register */
 77#define PCIEFD_REG_CAN_RX_CTL_ACK	0x0068	/* Rx control ACK register */
 78#define PCIEFD_REG_CAN_RX_DMA_ADDR_L	0x0070	/* 64-bits addr for Rx DMA */
 79#define PCIEFD_REG_CAN_RX_DMA_ADDR_H	0x0074
 80
 81/* CAN-FD channel misc register bits */
 82#define CANFD_MISC_TS_RST		0x00000001	/* timestamp cnt rst */
 83
 84/* CAN-FD channel Clock SELector Source & DIVider */
 85#define CANFD_CLK_SEL_DIV_MASK		0x00000007
 86#define CANFD_CLK_SEL_DIV_60MHZ		0x00000000	/* SRC=240MHz only */
 87#define CANFD_CLK_SEL_DIV_40MHZ		0x00000001	/* SRC=240MHz only */
 88#define CANFD_CLK_SEL_DIV_30MHZ		0x00000002	/* SRC=240MHz only */
 89#define CANFD_CLK_SEL_DIV_24MHZ		0x00000003	/* SRC=240MHz only */
 90#define CANFD_CLK_SEL_DIV_20MHZ		0x00000004	/* SRC=240MHz only */
 91
 92#define CANFD_CLK_SEL_SRC_MASK		0x00000008	/* 0=80MHz, 1=240MHz */
 93#define CANFD_CLK_SEL_SRC_240MHZ	0x00000008
 94#define CANFD_CLK_SEL_SRC_80MHZ		(~CANFD_CLK_SEL_SRC_240MHZ & \
 95							CANFD_CLK_SEL_SRC_MASK)
 96
 97#define CANFD_CLK_SEL_20MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
 98						CANFD_CLK_SEL_DIV_20MHZ)
 99#define CANFD_CLK_SEL_24MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
100						CANFD_CLK_SEL_DIV_24MHZ)
101#define CANFD_CLK_SEL_30MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
102						CANFD_CLK_SEL_DIV_30MHZ)
103#define CANFD_CLK_SEL_40MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
104						CANFD_CLK_SEL_DIV_40MHZ)
105#define CANFD_CLK_SEL_60MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
106						CANFD_CLK_SEL_DIV_60MHZ)
107#define CANFD_CLK_SEL_80MHZ		(CANFD_CLK_SEL_SRC_80MHZ)
108
109/* CAN-FD channel Rx/Tx control register bits */
110#define CANFD_CTL_UNC_BIT		0x00010000	/* Uncached DMA mem */
111#define CANFD_CTL_RST_BIT		0x00020000	/* reset DMA action */
112#define CANFD_CTL_IEN_BIT		0x00040000	/* IRQ enable */
113
114/* Rx IRQ Count and Time Limits */
115#define CANFD_CTL_IRQ_CL_DEF	16	/* Rx msg max nb per IRQ in Rx DMA */
116#define CANFD_CTL_IRQ_TL_DEF	10	/* Time before IRQ if < CL (x100 µs) */
117
118/* Tx anticipation window (link logical address should be aligned on 2K
119 * boundary)
120 */
121#define PCIEFD_TX_PAGE_COUNT	(PCIEFD_TX_DMA_SIZE / PCIEFD_TX_PAGE_SIZE)
122
123#define CANFD_MSG_LNK_TX	0x1001	/* Tx msgs link */
124
125/* 32-bits IRQ status fields, heading Rx DMA area */
126static inline int pciefd_irq_tag(u32 irq_status)
127{
128	return irq_status & 0x0000000f;
129}
130
131static inline int pciefd_irq_rx_cnt(u32 irq_status)
132{
133	return (irq_status & 0x000007f0) >> 4;
134}
135
136static inline int pciefd_irq_is_lnk(u32 irq_status)
137{
138	return irq_status & 0x00010000;
139}
140
141/* Rx record */
142struct pciefd_rx_dma {
143	__le32 irq_status;
144	__le32 sys_time_low;
145	__le32 sys_time_high;
146	struct pucan_rx_msg msg[];
147} __packed __aligned(4);
148
149/* Tx Link record */
150struct pciefd_tx_link {
151	__le16 size;
152	__le16 type;
153	__le32 laddr_lo;
154	__le32 laddr_hi;
155} __packed __aligned(4);
156
157/* Tx page descriptor */
158struct pciefd_page {
159	void *vbase;			/* page virtual address */
160	dma_addr_t lbase;		/* page logical address */
161	u32 offset;
162	u32 size;
163};
164
165/* CAN-FD channel object */
166struct pciefd_board;
167struct pciefd_can {
168	struct peak_canfd_priv ucan;	/* must be the first member */
169	void __iomem *reg_base;		/* channel config base addr */
170	struct pciefd_board *board;	/* reverse link */
171
172	struct pucan_command pucan_cmd;	/* command buffer */
173
174	dma_addr_t rx_dma_laddr;	/* DMA virtual and logical addr */
175	void *rx_dma_vaddr;		/* for Rx and Tx areas */
176	dma_addr_t tx_dma_laddr;
177	void *tx_dma_vaddr;
178
179	struct pciefd_page tx_pages[PCIEFD_TX_PAGE_COUNT];
180	u16 tx_pages_free;		/* free Tx pages counter */
181	u16 tx_page_index;		/* current page used for Tx */
182	spinlock_t tx_lock;
183
184	u32 irq_status;
185	u32 irq_tag;				/* next irq tag */
186};
187
188/* PEAK-PCIe FD board object */
189struct pciefd_board {
190	void __iomem *reg_base;
191	struct pci_dev *pci_dev;
192	int can_count;
193	spinlock_t cmd_lock;		/* 64-bits cmds must be atomic */
194	struct pciefd_can *can[];	/* array of network devices */
195};
196
197/* supported device ids. */
198static const struct pci_device_id peak_pciefd_tbl[] = {
199	{PEAK_PCI_VENDOR_ID, PEAK_PCIEFD_ID, PCI_ANY_ID, PCI_ANY_ID,},
200	{PEAK_PCI_VENDOR_ID, PCAN_CPCIEFD_ID, PCI_ANY_ID, PCI_ANY_ID,},
201	{PEAK_PCI_VENDOR_ID, PCAN_PCIE104FD_ID, PCI_ANY_ID, PCI_ANY_ID,},
202	{PEAK_PCI_VENDOR_ID, PCAN_MINIPCIEFD_ID, PCI_ANY_ID, PCI_ANY_ID,},
203	{PEAK_PCI_VENDOR_ID, PCAN_PCIEFD_OEM_ID, PCI_ANY_ID, PCI_ANY_ID,},
204	{PEAK_PCI_VENDOR_ID, PCAN_M2_ID, PCI_ANY_ID, PCI_ANY_ID,},
205	{0,}
206};
207
208MODULE_DEVICE_TABLE(pci, peak_pciefd_tbl);
209
210/* read a 32 bits value from a SYS block register */
211static inline u32 pciefd_sys_readreg(const struct pciefd_board *priv, u16 reg)
212{
213	return readl(priv->reg_base + reg);
214}
215
216/* write a 32 bits value into a SYS block register */
217static inline void pciefd_sys_writereg(const struct pciefd_board *priv,
218				       u32 val, u16 reg)
219{
220	writel(val, priv->reg_base + reg);
221}
222
223/* read a 32 bits value from CAN-FD block register */
224static inline u32 pciefd_can_readreg(const struct pciefd_can *priv, u16 reg)
225{
226	return readl(priv->reg_base + reg);
227}
228
229/* write a 32 bits value into a CAN-FD block register */
230static inline void pciefd_can_writereg(const struct pciefd_can *priv,
231				       u32 val, u16 reg)
232{
233	writel(val, priv->reg_base + reg);
234}
235
236/* give a channel logical Rx DMA address to the board */
237static void pciefd_can_setup_rx_dma(struct pciefd_can *priv)
238{
239#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
240	const u32 dma_addr_h = (u32)(priv->rx_dma_laddr >> 32);
241#else
242	const u32 dma_addr_h = 0;
243#endif
244
245	/* (DMA must be reset for Rx) */
246	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_RX_CTL_SET);
247
248	/* write the logical address of the Rx DMA area for this channel */
249	pciefd_can_writereg(priv, (u32)priv->rx_dma_laddr,
250			    PCIEFD_REG_CAN_RX_DMA_ADDR_L);
251	pciefd_can_writereg(priv, dma_addr_h, PCIEFD_REG_CAN_RX_DMA_ADDR_H);
252
253	/* also indicates that Rx DMA is cacheable */
254	pciefd_can_writereg(priv, CANFD_CTL_UNC_BIT, PCIEFD_REG_CAN_RX_CTL_CLR);
255}
256
257/* clear channel logical Rx DMA address from the board */
258static void pciefd_can_clear_rx_dma(struct pciefd_can *priv)
259{
260	/* DMA must be reset for Rx */
261	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_RX_CTL_SET);
262
263	/* clear the logical address of the Rx DMA area for this channel */
264	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_RX_DMA_ADDR_L);
265	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_RX_DMA_ADDR_H);
266}
267
268/* give a channel logical Tx DMA address to the board */
269static void pciefd_can_setup_tx_dma(struct pciefd_can *priv)
270{
271#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
272	const u32 dma_addr_h = (u32)(priv->tx_dma_laddr >> 32);
273#else
274	const u32 dma_addr_h = 0;
275#endif
276
277	/* (DMA must be reset for Tx) */
278	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_TX_CTL_SET);
279
280	/* write the logical address of the Tx DMA area for this channel */
281	pciefd_can_writereg(priv, (u32)priv->tx_dma_laddr,
282			    PCIEFD_REG_CAN_TX_DMA_ADDR_L);
283	pciefd_can_writereg(priv, dma_addr_h, PCIEFD_REG_CAN_TX_DMA_ADDR_H);
284
285	/* also indicates that Tx DMA is cacheable */
286	pciefd_can_writereg(priv, CANFD_CTL_UNC_BIT, PCIEFD_REG_CAN_TX_CTL_CLR);
287}
288
289/* clear channel logical Tx DMA address from the board */
290static void pciefd_can_clear_tx_dma(struct pciefd_can *priv)
291{
292	/* DMA must be reset for Tx */
293	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_TX_CTL_SET);
294
295	/* clear the logical address of the Tx DMA area for this channel */
296	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_TX_DMA_ADDR_L);
297	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_TX_DMA_ADDR_H);
298}
299
300static void pciefd_can_ack_rx_dma(struct pciefd_can *priv)
301{
302	/* read value of current IRQ tag and inc it for next one */
303	priv->irq_tag = le32_to_cpu(*(__le32 *)priv->rx_dma_vaddr);
304	priv->irq_tag++;
305	priv->irq_tag &= 0xf;
306
307	/* write the next IRQ tag for this CAN */
308	pciefd_can_writereg(priv, priv->irq_tag, PCIEFD_REG_CAN_RX_CTL_ACK);
309}
310
311/* IRQ handler */
312static irqreturn_t pciefd_irq_handler(int irq, void *arg)
313{
314	struct pciefd_can *priv = arg;
315	struct pciefd_rx_dma *rx_dma = priv->rx_dma_vaddr;
316
317	/* INTA mode only to sync with PCIe transaction */
318	if (!pci_dev_msi_enabled(priv->board->pci_dev))
319		(void)pciefd_sys_readreg(priv->board, PCIEFD_REG_SYS_VER1);
320
321	/* read IRQ status from the first 32-bits of the Rx DMA area */
322	priv->irq_status = le32_to_cpu(rx_dma->irq_status);
323
324	/* check if this (shared) IRQ is for this CAN */
325	if (pciefd_irq_tag(priv->irq_status) != priv->irq_tag)
326		return IRQ_NONE;
327
328	/* handle rx messages (if any) */
329	peak_canfd_handle_msgs_list(&priv->ucan,
330				    rx_dma->msg,
331				    pciefd_irq_rx_cnt(priv->irq_status));
332
333	/* handle tx link interrupt (if any) */
334	if (pciefd_irq_is_lnk(priv->irq_status)) {
335		unsigned long flags;
336
337		spin_lock_irqsave(&priv->tx_lock, flags);
338		priv->tx_pages_free++;
339		spin_unlock_irqrestore(&priv->tx_lock, flags);
340
341		/* wake producer up (only if enough room in echo_skb array) */
342		spin_lock_irqsave(&priv->ucan.echo_lock, flags);
343		if (!priv->ucan.can.echo_skb[priv->ucan.echo_idx])
344			netif_wake_queue(priv->ucan.ndev);
345
346		spin_unlock_irqrestore(&priv->ucan.echo_lock, flags);
347	}
348
349	/* re-enable Rx DMA transfer for this CAN */
350	pciefd_can_ack_rx_dma(priv);
351
352	return IRQ_HANDLED;
353}
354
355static int pciefd_enable_tx_path(struct peak_canfd_priv *ucan)
356{
357	struct pciefd_can *priv = (struct pciefd_can *)ucan;
358	int i;
359
360	/* initialize the Tx pages descriptors */
361	priv->tx_pages_free = PCIEFD_TX_PAGE_COUNT - 1;
362	priv->tx_page_index = 0;
363
364	priv->tx_pages[0].vbase = priv->tx_dma_vaddr;
365	priv->tx_pages[0].lbase = priv->tx_dma_laddr;
366
367	for (i = 0; i < PCIEFD_TX_PAGE_COUNT; i++) {
368		priv->tx_pages[i].offset = 0;
369		priv->tx_pages[i].size = PCIEFD_TX_PAGE_SIZE -
370					 sizeof(struct pciefd_tx_link);
371		if (i) {
372			priv->tx_pages[i].vbase =
373					  priv->tx_pages[i - 1].vbase +
374					  PCIEFD_TX_PAGE_SIZE;
375			priv->tx_pages[i].lbase =
376					  priv->tx_pages[i - 1].lbase +
377					  PCIEFD_TX_PAGE_SIZE;
378		}
379	}
380
381	/* setup Tx DMA addresses into IP core */
382	pciefd_can_setup_tx_dma(priv);
383
384	/* start (TX_RST=0) Tx Path */
385	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_TX_CTL_CLR);
386
387	return 0;
388}
389
390/* board specific CANFD command pre-processing */
391static int pciefd_pre_cmd(struct peak_canfd_priv *ucan)
392{
393	struct pciefd_can *priv = (struct pciefd_can *)ucan;
394	u16 cmd = pucan_cmd_get_opcode(&priv->pucan_cmd);
395	int err;
396
397	/* pre-process command */
398	switch (cmd) {
399	case PUCAN_CMD_NORMAL_MODE:
400	case PUCAN_CMD_LISTEN_ONLY_MODE:
401
402		if (ucan->can.state == CAN_STATE_BUS_OFF)
403			break;
404
405		/* going into operational mode: setup IRQ handler */
406		err = request_irq(priv->ucan.ndev->irq,
407				  pciefd_irq_handler,
408				  IRQF_SHARED,
409				  PCIEFD_DRV_NAME,
410				  priv);
411		if (err)
412			return err;
413
414		/* setup Rx DMA address */
415		pciefd_can_setup_rx_dma(priv);
416
417		/* setup max count of msgs per IRQ */
418		pciefd_can_writereg(priv, (CANFD_CTL_IRQ_TL_DEF) << 8 |
419				    CANFD_CTL_IRQ_CL_DEF,
420				    PCIEFD_REG_CAN_RX_CTL_WRT);
421
422		/* clear DMA RST for Rx (Rx start) */
423		pciefd_can_writereg(priv, CANFD_CTL_RST_BIT,
424				    PCIEFD_REG_CAN_RX_CTL_CLR);
425
426		/* reset timestamps */
427		pciefd_can_writereg(priv, !CANFD_MISC_TS_RST,
428				    PCIEFD_REG_CAN_MISC);
429
430		/* do an initial ACK */
431		pciefd_can_ack_rx_dma(priv);
432
433		/* enable IRQ for this CAN after having set next irq_tag */
434		pciefd_can_writereg(priv, CANFD_CTL_IEN_BIT,
435				    PCIEFD_REG_CAN_RX_CTL_SET);
436
437		/* Tx path will be setup as soon as RX_BARRIER is received */
438		break;
439	default:
440		break;
441	}
442
443	return 0;
444}
445
446/* write a command */
447static int pciefd_write_cmd(struct peak_canfd_priv *ucan)
448{
449	struct pciefd_can *priv = (struct pciefd_can *)ucan;
450	unsigned long flags;
451
452	/* 64-bits command is atomic */
453	spin_lock_irqsave(&priv->board->cmd_lock, flags);
454
455	pciefd_can_writereg(priv, *(u32 *)ucan->cmd_buffer,
456			    PCIEFD_REG_CAN_CMD_PORT_L);
457	pciefd_can_writereg(priv, *(u32 *)(ucan->cmd_buffer + 4),
458			    PCIEFD_REG_CAN_CMD_PORT_H);
459
460	spin_unlock_irqrestore(&priv->board->cmd_lock, flags);
461
462	return 0;
463}
464
465/* board specific CANFD command post-processing */
466static int pciefd_post_cmd(struct peak_canfd_priv *ucan)
467{
468	struct pciefd_can *priv = (struct pciefd_can *)ucan;
469	u16 cmd = pucan_cmd_get_opcode(&priv->pucan_cmd);
470
471	switch (cmd) {
472	case PUCAN_CMD_RESET_MODE:
473
474		if (ucan->can.state == CAN_STATE_STOPPED)
475			break;
476
477		/* controller now in reset mode: */
478
479		/* disable IRQ for this CAN */
480		pciefd_can_writereg(priv, CANFD_CTL_IEN_BIT,
481				    PCIEFD_REG_CAN_RX_CTL_CLR);
482
483		/* stop and reset DMA addresses in Tx/Rx engines */
484		pciefd_can_clear_tx_dma(priv);
485		pciefd_can_clear_rx_dma(priv);
486
487		/* wait for above commands to complete (read cycle) */
488		(void)pciefd_sys_readreg(priv->board, PCIEFD_REG_SYS_VER1);
489
490		free_irq(priv->ucan.ndev->irq, priv);
491
492		ucan->can.state = CAN_STATE_STOPPED;
493
494		break;
495	}
496
497	return 0;
498}
499
500static void *pciefd_alloc_tx_msg(struct peak_canfd_priv *ucan, u16 msg_size,
501				 int *room_left)
502{
503	struct pciefd_can *priv = (struct pciefd_can *)ucan;
504	struct pciefd_page *page = priv->tx_pages + priv->tx_page_index;
505	unsigned long flags;
506	void *msg;
507
508	spin_lock_irqsave(&priv->tx_lock, flags);
509
510	if (page->offset + msg_size > page->size) {
511		struct pciefd_tx_link *lk;
512
513		/* not enough space in this page: try another one */
514		if (!priv->tx_pages_free) {
515			spin_unlock_irqrestore(&priv->tx_lock, flags);
516
517			/* Tx overflow */
518			return NULL;
519		}
520
521		priv->tx_pages_free--;
522
523		/* keep address of the very last free slot of current page */
524		lk = page->vbase + page->offset;
525
526		/* next, move on a new free page */
527		priv->tx_page_index = (priv->tx_page_index + 1) %
528				      PCIEFD_TX_PAGE_COUNT;
529		page = priv->tx_pages + priv->tx_page_index;
530
531		/* put link record to this new page at the end of prev one */
532		lk->size = cpu_to_le16(sizeof(*lk));
533		lk->type = cpu_to_le16(CANFD_MSG_LNK_TX);
534		lk->laddr_lo = cpu_to_le32(page->lbase);
535
536#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
537		lk->laddr_hi = cpu_to_le32(page->lbase >> 32);
538#else
539		lk->laddr_hi = 0;
540#endif
541		/* next msgs will be put from the begininng of this new page */
542		page->offset = 0;
543	}
544
545	*room_left = priv->tx_pages_free * page->size;
546
547	spin_unlock_irqrestore(&priv->tx_lock, flags);
548
549	msg = page->vbase + page->offset;
550
551	/* give back room left in the tx ring */
552	*room_left += page->size - (page->offset + msg_size);
553
554	return msg;
555}
556
557static int pciefd_write_tx_msg(struct peak_canfd_priv *ucan,
558			       struct pucan_tx_msg *msg)
559{
560	struct pciefd_can *priv = (struct pciefd_can *)ucan;
561	struct pciefd_page *page = priv->tx_pages + priv->tx_page_index;
562
563	/* this slot is now reserved for writing the frame */
564	page->offset += le16_to_cpu(msg->size);
565
566	/* tell the board a frame has been written in Tx DMA area */
567	pciefd_can_writereg(priv, 1, PCIEFD_REG_CAN_TX_REQ_ACC);
568
569	return 0;
570}
571
572/* probe for CAN-FD channel #pciefd_board->can_count */
573static int pciefd_can_probe(struct pciefd_board *pciefd)
574{
575	struct net_device *ndev;
576	struct pciefd_can *priv;
577	u32 clk;
578	int err;
579
580	/* allocate the candev object with default isize of echo skbs ring */
581	ndev = alloc_peak_canfd_dev(sizeof(*priv), pciefd->can_count,
582				    PCIEFD_ECHO_SKB_MAX);
583	if (!ndev) {
584		dev_err(&pciefd->pci_dev->dev,
585			"failed to alloc candev object\n");
586		goto failure;
587	}
588
589	priv = netdev_priv(ndev);
590
591	/* fill-in candev private object: */
592
593	/* setup PCIe-FD own callbacks */
594	priv->ucan.pre_cmd = pciefd_pre_cmd;
595	priv->ucan.write_cmd = pciefd_write_cmd;
596	priv->ucan.post_cmd = pciefd_post_cmd;
597	priv->ucan.enable_tx_path = pciefd_enable_tx_path;
598	priv->ucan.alloc_tx_msg = pciefd_alloc_tx_msg;
599	priv->ucan.write_tx_msg = pciefd_write_tx_msg;
600
601	/* setup PCIe-FD own command buffer */
602	priv->ucan.cmd_buffer = &priv->pucan_cmd;
603	priv->ucan.cmd_maxlen = sizeof(priv->pucan_cmd);
604
605	priv->board = pciefd;
606
607	/* CAN config regs block address */
608	priv->reg_base = pciefd->reg_base + PCIEFD_CANX_OFF(priv->ucan.index);
609
610	/* allocate non-cacheable DMA'able 4KB memory area for Rx */
611	priv->rx_dma_vaddr = dmam_alloc_coherent(&pciefd->pci_dev->dev,
612						 PCIEFD_RX_DMA_SIZE,
613						 &priv->rx_dma_laddr,
614						 GFP_KERNEL);
615	if (!priv->rx_dma_vaddr) {
616		dev_err(&pciefd->pci_dev->dev,
617			"Rx dmam_alloc_coherent(%u) failure\n",
618			PCIEFD_RX_DMA_SIZE);
619		goto err_free_candev;
620	}
621
622	/* allocate non-cacheable DMA'able 4KB memory area for Tx */
623	priv->tx_dma_vaddr = dmam_alloc_coherent(&pciefd->pci_dev->dev,
624						 PCIEFD_TX_DMA_SIZE,
625						 &priv->tx_dma_laddr,
626						 GFP_KERNEL);
627	if (!priv->tx_dma_vaddr) {
628		dev_err(&pciefd->pci_dev->dev,
629			"Tx dmam_alloc_coherent(%u) failure\n",
630			PCIEFD_TX_DMA_SIZE);
631		goto err_free_candev;
632	}
633
634	/* CAN clock in RST mode */
635	pciefd_can_writereg(priv, CANFD_MISC_TS_RST, PCIEFD_REG_CAN_MISC);
636
637	/* read current clock value */
638	clk = pciefd_can_readreg(priv, PCIEFD_REG_CAN_CLK_SEL);
639	switch (clk) {
640	case CANFD_CLK_SEL_20MHZ:
641		priv->ucan.can.clock.freq = 20 * 1000 * 1000;
642		break;
643	case CANFD_CLK_SEL_24MHZ:
644		priv->ucan.can.clock.freq = 24 * 1000 * 1000;
645		break;
646	case CANFD_CLK_SEL_30MHZ:
647		priv->ucan.can.clock.freq = 30 * 1000 * 1000;
648		break;
649	case CANFD_CLK_SEL_40MHZ:
650		priv->ucan.can.clock.freq = 40 * 1000 * 1000;
651		break;
652	case CANFD_CLK_SEL_60MHZ:
653		priv->ucan.can.clock.freq = 60 * 1000 * 1000;
654		break;
655	default:
656		pciefd_can_writereg(priv, CANFD_CLK_SEL_80MHZ,
657				    PCIEFD_REG_CAN_CLK_SEL);
658
659		fallthrough;
660	case CANFD_CLK_SEL_80MHZ:
661		priv->ucan.can.clock.freq = 80 * 1000 * 1000;
662		break;
663	}
664
665	ndev->irq = pciefd->pci_dev->irq;
666
667	SET_NETDEV_DEV(ndev, &pciefd->pci_dev->dev);
668
669	err = register_candev(ndev);
670	if (err) {
671		dev_err(&pciefd->pci_dev->dev,
672			"couldn't register CAN device: %d\n", err);
673		goto err_free_candev;
674	}
675
676	spin_lock_init(&priv->tx_lock);
677
678	/* save the object address in the board structure */
679	pciefd->can[pciefd->can_count] = priv;
680
681	dev_info(&pciefd->pci_dev->dev, "%s at reg_base=0x%p irq=%d\n",
682		 ndev->name, priv->reg_base, ndev->irq);
683
684	return 0;
685
686err_free_candev:
687	free_candev(ndev);
688
689failure:
690	return -ENOMEM;
691}
692
693/* remove a CAN-FD channel by releasing all of its resources */
694static void pciefd_can_remove(struct pciefd_can *priv)
695{
696	/* unregister (close) the can device to go back to RST mode first */
697	unregister_candev(priv->ucan.ndev);
698
699	/* finally, free the candev object */
700	free_candev(priv->ucan.ndev);
701}
702
703/* remove all CAN-FD channels by releasing their own resources */
704static void pciefd_can_remove_all(struct pciefd_board *pciefd)
705{
706	while (pciefd->can_count > 0)
707		pciefd_can_remove(pciefd->can[--pciefd->can_count]);
708}
709
710/* probe for the entire device */
711static int peak_pciefd_probe(struct pci_dev *pdev,
712			     const struct pci_device_id *ent)
713{
714	struct pciefd_board *pciefd;
715	int err, can_count;
716	u16 sub_sys_id;
717	u8 hw_ver_major;
718	u8 hw_ver_minor;
719	u8 hw_ver_sub;
720	u32 v2;
721
722	err = pci_enable_device(pdev);
723	if (err)
724		return err;
725	err = pci_request_regions(pdev, PCIEFD_DRV_NAME);
726	if (err)
727		goto err_disable_pci;
728
729	/* the number of channels depends on sub-system id */
730	err = pci_read_config_word(pdev, PCI_SUBSYSTEM_ID, &sub_sys_id);
731	if (err)
732		goto err_release_regions;
733
734	dev_dbg(&pdev->dev, "probing device %04x:%04x:%04x\n",
735		pdev->vendor, pdev->device, sub_sys_id);
736
737	if (sub_sys_id >= 0x0012)
738		can_count = 4;
739	else if (sub_sys_id >= 0x0010)
740		can_count = 3;
741	else if (sub_sys_id >= 0x0004)
742		can_count = 2;
743	else
744		can_count = 1;
745
746	/* allocate board structure object */
747	pciefd = devm_kzalloc(&pdev->dev, struct_size(pciefd, can, can_count),
748			      GFP_KERNEL);
749	if (!pciefd) {
750		err = -ENOMEM;
751		goto err_release_regions;
752	}
753
754	/* initialize the board structure */
755	pciefd->pci_dev = pdev;
756	spin_lock_init(&pciefd->cmd_lock);
757
758	/* save the PCI BAR0 virtual address for further system regs access */
759	pciefd->reg_base = pci_iomap(pdev, 0, PCIEFD_BAR0_SIZE);
760	if (!pciefd->reg_base) {
761		dev_err(&pdev->dev, "failed to map PCI resource #0\n");
762		err = -ENOMEM;
763		goto err_release_regions;
764	}
765
766	/* read the firmware version number */
767	v2 = pciefd_sys_readreg(pciefd, PCIEFD_REG_SYS_VER2);
768
769	hw_ver_major = (v2 & 0x0000f000) >> 12;
770	hw_ver_minor = (v2 & 0x00000f00) >> 8;
771	hw_ver_sub = (v2 & 0x000000f0) >> 4;
772
773	dev_info(&pdev->dev,
774		 "%ux CAN-FD PCAN-PCIe FPGA v%u.%u.%u:\n", can_count,
775		 hw_ver_major, hw_ver_minor, hw_ver_sub);
776
777#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
778	/* FW < v3.3.0 DMA logic doesn't handle correctly the mix of 32-bit and
779	 * 64-bit logical addresses: this workaround forces usage of 32-bit
780	 * DMA addresses only when such a fw is detected.
781	 */
782	if (PCIEFD_FW_VERSION(hw_ver_major, hw_ver_minor, hw_ver_sub) <
783	    PCIEFD_FW_VERSION(3, 3, 0)) {
784		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
785		if (err)
786			dev_warn(&pdev->dev,
787				 "warning: can't set DMA mask %llxh (err %d)\n",
788				 DMA_BIT_MASK(32), err);
789	}
790#endif
791
792	/* stop system clock */
793	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_CLK_EN,
794			    PCIEFD_REG_SYS_CTL_CLR);
795
796	pci_set_master(pdev);
797
798	/* create now the corresponding channels objects */
799	while (pciefd->can_count < can_count) {
800		err = pciefd_can_probe(pciefd);
801		if (err)
802			goto err_free_canfd;
803
804		pciefd->can_count++;
805	}
806
807	/* set system timestamps counter in RST mode */
808	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_TS_RST,
809			    PCIEFD_REG_SYS_CTL_SET);
810
811	/* wait a bit (read cycle) */
812	(void)pciefd_sys_readreg(pciefd, PCIEFD_REG_SYS_VER1);
813
814	/* free all clocks */
815	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_TS_RST,
816			    PCIEFD_REG_SYS_CTL_CLR);
817
818	/* start system clock */
819	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_CLK_EN,
820			    PCIEFD_REG_SYS_CTL_SET);
821
822	/* remember the board structure address in the device user data */
823	pci_set_drvdata(pdev, pciefd);
824
825	return 0;
826
827err_free_canfd:
828	pciefd_can_remove_all(pciefd);
829
830	pci_iounmap(pdev, pciefd->reg_base);
831
832err_release_regions:
833	pci_release_regions(pdev);
834
835err_disable_pci:
836	pci_disable_device(pdev);
837
838	/* pci_xxx_config_word() return positive PCIBIOS_xxx error codes while
839	 * the probe() function must return a negative errno in case of failure
840	 * (err is unchanged if negative)
841	 */
842	return pcibios_err_to_errno(err);
843}
844
845/* free the board structure object, as well as its resources: */
846static void peak_pciefd_remove(struct pci_dev *pdev)
847{
848	struct pciefd_board *pciefd = pci_get_drvdata(pdev);
849
850	/* release CAN-FD channels resources */
851	pciefd_can_remove_all(pciefd);
852
853	pci_iounmap(pdev, pciefd->reg_base);
854
855	pci_release_regions(pdev);
856	pci_disable_device(pdev);
857}
858
859static struct pci_driver peak_pciefd_driver = {
860	.name = PCIEFD_DRV_NAME,
861	.id_table = peak_pciefd_tbl,
862	.probe = peak_pciefd_probe,
863	.remove = peak_pciefd_remove,
864};
865
866module_pci_driver(peak_pciefd_driver);