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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
  4 * Copyright (C) 2012 Stephane Grosjean <s.grosjean@peak-system.com>
  5 *
  6 * Derived from the PCAN project file driver/src/pcan_pci.c:
  7 *
  8 * Copyright (C) 2001-2006  PEAK System-Technik GmbH
  9 */
 10
 11#include <linux/kernel.h>
 12#include <linux/module.h>
 13#include <linux/interrupt.h>
 14#include <linux/netdevice.h>
 15#include <linux/delay.h>
 16#include <linux/pci.h>
 17#include <linux/io.h>
 18#include <linux/can.h>
 19#include <linux/can/dev.h>
 20
 21#include "peak_canfd_user.h"
 22
 23MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
 24MODULE_DESCRIPTION("Socket-CAN driver for PEAK PCAN PCIe/M.2 FD family cards");
 25MODULE_SUPPORTED_DEVICE("PEAK PCAN PCIe/M.2 FD CAN cards");
 26MODULE_LICENSE("GPL v2");
 27
 28#define PCIEFD_DRV_NAME		"peak_pciefd"
 29
 30#define PEAK_PCI_VENDOR_ID	0x001c	/* The PCI device and vendor IDs */
 31#define PEAK_PCIEFD_ID		0x0013	/* for PCIe slot cards */
 32#define PCAN_CPCIEFD_ID		0x0014	/* for Compact-PCI Serial slot cards */
 33#define PCAN_PCIE104FD_ID	0x0017	/* for PCIe-104 Express slot cards */
 34#define PCAN_MINIPCIEFD_ID      0x0018	/* for mini-PCIe slot cards */
 35#define PCAN_PCIEFD_OEM_ID      0x0019	/* for PCIe slot OEM cards */
 36#define PCAN_M2_ID		0x001a	/* for M2 slot cards */
 37
 38/* PEAK PCIe board access description */
 39#define PCIEFD_BAR0_SIZE		(64 * 1024)
 40#define PCIEFD_RX_DMA_SIZE		(4 * 1024)
 41#define PCIEFD_TX_DMA_SIZE		(4 * 1024)
 42
 43#define PCIEFD_TX_PAGE_SIZE		(2 * 1024)
 44
 45/* System Control Registers */
 46#define PCIEFD_REG_SYS_CTL_SET		0x0000	/* set bits */
 47#define PCIEFD_REG_SYS_CTL_CLR		0x0004	/* clear bits */
 48
 49/* Version info registers */
 50#define PCIEFD_REG_SYS_VER1		0x0040	/* version reg #1 */
 51#define PCIEFD_REG_SYS_VER2		0x0044	/* version reg #2 */
 52
 53#define PCIEFD_FW_VERSION(x, y, z)	(((u32)(x) << 24) | \
 54					 ((u32)(y) << 16) | \
 55					 ((u32)(z) << 8))
 56
 57/* System Control Registers Bits */
 58#define PCIEFD_SYS_CTL_TS_RST		0x00000001	/* timestamp clock */
 59#define PCIEFD_SYS_CTL_CLK_EN		0x00000002	/* system clock */
 60
 61/* CAN-FD channel addresses */
 62#define PCIEFD_CANX_OFF(c)		(((c) + 1) * 0x1000)
 63
 64#define PCIEFD_ECHO_SKB_MAX		PCANFD_ECHO_SKB_DEF
 65
 66/* CAN-FD channel registers */
 67#define PCIEFD_REG_CAN_MISC		0x0000	/* Misc. control */
 68#define PCIEFD_REG_CAN_CLK_SEL		0x0008	/* Clock selector */
 69#define PCIEFD_REG_CAN_CMD_PORT_L	0x0010	/* 64-bits command port */
 70#define PCIEFD_REG_CAN_CMD_PORT_H	0x0014
 71#define PCIEFD_REG_CAN_TX_REQ_ACC	0x0020	/* Tx request accumulator */
 72#define PCIEFD_REG_CAN_TX_CTL_SET	0x0030	/* Tx control set register */
 73#define PCIEFD_REG_CAN_TX_CTL_CLR	0x0038	/* Tx control clear register */
 74#define PCIEFD_REG_CAN_TX_DMA_ADDR_L	0x0040	/* 64-bits addr for Tx DMA */
 75#define PCIEFD_REG_CAN_TX_DMA_ADDR_H	0x0044
 76#define PCIEFD_REG_CAN_RX_CTL_SET	0x0050	/* Rx control set register */
 77#define PCIEFD_REG_CAN_RX_CTL_CLR	0x0058	/* Rx control clear register */
 78#define PCIEFD_REG_CAN_RX_CTL_WRT	0x0060	/* Rx control write register */
 79#define PCIEFD_REG_CAN_RX_CTL_ACK	0x0068	/* Rx control ACK register */
 80#define PCIEFD_REG_CAN_RX_DMA_ADDR_L	0x0070	/* 64-bits addr for Rx DMA */
 81#define PCIEFD_REG_CAN_RX_DMA_ADDR_H	0x0074
 82
 83/* CAN-FD channel misc register bits */
 84#define CANFD_MISC_TS_RST		0x00000001	/* timestamp cnt rst */
 85
 86/* CAN-FD channel Clock SELector Source & DIVider */
 87#define CANFD_CLK_SEL_DIV_MASK		0x00000007
 88#define CANFD_CLK_SEL_DIV_60MHZ		0x00000000	/* SRC=240MHz only */
 89#define CANFD_CLK_SEL_DIV_40MHZ		0x00000001	/* SRC=240MHz only */
 90#define CANFD_CLK_SEL_DIV_30MHZ		0x00000002	/* SRC=240MHz only */
 91#define CANFD_CLK_SEL_DIV_24MHZ		0x00000003	/* SRC=240MHz only */
 92#define CANFD_CLK_SEL_DIV_20MHZ		0x00000004	/* SRC=240MHz only */
 93
 94#define CANFD_CLK_SEL_SRC_MASK		0x00000008	/* 0=80MHz, 1=240MHz */
 95#define CANFD_CLK_SEL_SRC_240MHZ	0x00000008
 96#define CANFD_CLK_SEL_SRC_80MHZ		(~CANFD_CLK_SEL_SRC_240MHZ & \
 97							CANFD_CLK_SEL_SRC_MASK)
 98
 99#define CANFD_CLK_SEL_20MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
100						CANFD_CLK_SEL_DIV_20MHZ)
101#define CANFD_CLK_SEL_24MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
102						CANFD_CLK_SEL_DIV_24MHZ)
103#define CANFD_CLK_SEL_30MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
104						CANFD_CLK_SEL_DIV_30MHZ)
105#define CANFD_CLK_SEL_40MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
106						CANFD_CLK_SEL_DIV_40MHZ)
107#define CANFD_CLK_SEL_60MHZ		(CANFD_CLK_SEL_SRC_240MHZ |\
108						CANFD_CLK_SEL_DIV_60MHZ)
109#define CANFD_CLK_SEL_80MHZ		(CANFD_CLK_SEL_SRC_80MHZ)
110
111/* CAN-FD channel Rx/Tx control register bits */
112#define CANFD_CTL_UNC_BIT		0x00010000	/* Uncached DMA mem */
113#define CANFD_CTL_RST_BIT		0x00020000	/* reset DMA action */
114#define CANFD_CTL_IEN_BIT		0x00040000	/* IRQ enable */
115
116/* Rx IRQ Count and Time Limits */
117#define CANFD_CTL_IRQ_CL_DEF	16	/* Rx msg max nb per IRQ in Rx DMA */
118#define CANFD_CTL_IRQ_TL_DEF	10	/* Time before IRQ if < CL (x100 µs) */
119
120#define CANFD_OPTIONS_SET	(CANFD_OPTION_ERROR | CANFD_OPTION_BUSLOAD)
121
122/* Tx anticipation window (link logical address should be aligned on 2K
123 * boundary)
124 */
125#define PCIEFD_TX_PAGE_COUNT	(PCIEFD_TX_DMA_SIZE / PCIEFD_TX_PAGE_SIZE)
126
127#define CANFD_MSG_LNK_TX	0x1001	/* Tx msgs link */
128
129/* 32-bits IRQ status fields, heading Rx DMA area */
130static inline int pciefd_irq_tag(u32 irq_status)
131{
132	return irq_status & 0x0000000f;
133}
134
135static inline int pciefd_irq_rx_cnt(u32 irq_status)
136{
137	return (irq_status & 0x000007f0) >> 4;
138}
139
140static inline int pciefd_irq_is_lnk(u32 irq_status)
141{
142	return irq_status & 0x00010000;
143}
144
145/* Rx record */
146struct pciefd_rx_dma {
147	__le32 irq_status;
148	__le32 sys_time_low;
149	__le32 sys_time_high;
150	struct pucan_rx_msg msg[0];
151} __packed __aligned(4);
152
153/* Tx Link record */
154struct pciefd_tx_link {
155	__le16 size;
156	__le16 type;
157	__le32 laddr_lo;
158	__le32 laddr_hi;
159} __packed __aligned(4);
160
161/* Tx page descriptor */
162struct pciefd_page {
163	void *vbase;			/* page virtual address */
164	dma_addr_t lbase;		/* page logical address */
165	u32 offset;
166	u32 size;
167};
168
169/* CAN-FD channel object */
170struct pciefd_board;
171struct pciefd_can {
172	struct peak_canfd_priv ucan;	/* must be the first member */
173	void __iomem *reg_base;		/* channel config base addr */
174	struct pciefd_board *board;	/* reverse link */
175
176	struct pucan_command pucan_cmd;	/* command buffer */
177
178	dma_addr_t rx_dma_laddr;	/* DMA virtual and logical addr */
179	void *rx_dma_vaddr;		/* for Rx and Tx areas */
180	dma_addr_t tx_dma_laddr;
181	void *tx_dma_vaddr;
182
183	struct pciefd_page tx_pages[PCIEFD_TX_PAGE_COUNT];
184	u16 tx_pages_free;		/* free Tx pages counter */
185	u16 tx_page_index;		/* current page used for Tx */
186	spinlock_t tx_lock;
187
188	u32 irq_status;
189	u32 irq_tag;				/* next irq tag */
190};
191
192/* PEAK-PCIe FD board object */
193struct pciefd_board {
194	void __iomem *reg_base;
195	struct pci_dev *pci_dev;
196	int can_count;
197	spinlock_t cmd_lock;		/* 64-bits cmds must be atomic */
198	struct pciefd_can *can[0];	/* array of network devices */
199};
200
201/* supported device ids. */
202static const struct pci_device_id peak_pciefd_tbl[] = {
203	{PEAK_PCI_VENDOR_ID, PEAK_PCIEFD_ID, PCI_ANY_ID, PCI_ANY_ID,},
204	{PEAK_PCI_VENDOR_ID, PCAN_CPCIEFD_ID, PCI_ANY_ID, PCI_ANY_ID,},
205	{PEAK_PCI_VENDOR_ID, PCAN_PCIE104FD_ID, PCI_ANY_ID, PCI_ANY_ID,},
206	{PEAK_PCI_VENDOR_ID, PCAN_MINIPCIEFD_ID, PCI_ANY_ID, PCI_ANY_ID,},
207	{PEAK_PCI_VENDOR_ID, PCAN_PCIEFD_OEM_ID, PCI_ANY_ID, PCI_ANY_ID,},
208	{PEAK_PCI_VENDOR_ID, PCAN_M2_ID, PCI_ANY_ID, PCI_ANY_ID,},
209	{0,}
210};
211
212MODULE_DEVICE_TABLE(pci, peak_pciefd_tbl);
213
214/* read a 32 bits value from a SYS block register */
215static inline u32 pciefd_sys_readreg(const struct pciefd_board *priv, u16 reg)
216{
217	return readl(priv->reg_base + reg);
218}
219
220/* write a 32 bits value into a SYS block register */
221static inline void pciefd_sys_writereg(const struct pciefd_board *priv,
222				       u32 val, u16 reg)
223{
224	writel(val, priv->reg_base + reg);
225}
226
227/* read a 32 bits value from CAN-FD block register */
228static inline u32 pciefd_can_readreg(const struct pciefd_can *priv, u16 reg)
229{
230	return readl(priv->reg_base + reg);
231}
232
233/* write a 32 bits value into a CAN-FD block register */
234static inline void pciefd_can_writereg(const struct pciefd_can *priv,
235				       u32 val, u16 reg)
236{
237	writel(val, priv->reg_base + reg);
238}
239
240/* give a channel logical Rx DMA address to the board */
241static void pciefd_can_setup_rx_dma(struct pciefd_can *priv)
242{
243#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
244	const u32 dma_addr_h = (u32)(priv->rx_dma_laddr >> 32);
245#else
246	const u32 dma_addr_h = 0;
247#endif
248
249	/* (DMA must be reset for Rx) */
250	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_RX_CTL_SET);
251
252	/* write the logical address of the Rx DMA area for this channel */
253	pciefd_can_writereg(priv, (u32)priv->rx_dma_laddr,
254			    PCIEFD_REG_CAN_RX_DMA_ADDR_L);
255	pciefd_can_writereg(priv, dma_addr_h, PCIEFD_REG_CAN_RX_DMA_ADDR_H);
256
257	/* also indicates that Rx DMA is cacheable */
258	pciefd_can_writereg(priv, CANFD_CTL_UNC_BIT, PCIEFD_REG_CAN_RX_CTL_CLR);
259}
260
261/* clear channel logical Rx DMA address from the board */
262static void pciefd_can_clear_rx_dma(struct pciefd_can *priv)
263{
264	/* DMA must be reset for Rx */
265	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_RX_CTL_SET);
266
267	/* clear the logical address of the Rx DMA area for this channel */
268	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_RX_DMA_ADDR_L);
269	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_RX_DMA_ADDR_H);
270}
271
272/* give a channel logical Tx DMA address to the board */
273static void pciefd_can_setup_tx_dma(struct pciefd_can *priv)
274{
275#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
276	const u32 dma_addr_h = (u32)(priv->tx_dma_laddr >> 32);
277#else
278	const u32 dma_addr_h = 0;
279#endif
280
281	/* (DMA must be reset for Tx) */
282	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_TX_CTL_SET);
283
284	/* write the logical address of the Tx DMA area for this channel */
285	pciefd_can_writereg(priv, (u32)priv->tx_dma_laddr,
286			    PCIEFD_REG_CAN_TX_DMA_ADDR_L);
287	pciefd_can_writereg(priv, dma_addr_h, PCIEFD_REG_CAN_TX_DMA_ADDR_H);
288
289	/* also indicates that Tx DMA is cacheable */
290	pciefd_can_writereg(priv, CANFD_CTL_UNC_BIT, PCIEFD_REG_CAN_TX_CTL_CLR);
291}
292
293/* clear channel logical Tx DMA address from the board */
294static void pciefd_can_clear_tx_dma(struct pciefd_can *priv)
295{
296	/* DMA must be reset for Tx */
297	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_TX_CTL_SET);
298
299	/* clear the logical address of the Tx DMA area for this channel */
300	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_TX_DMA_ADDR_L);
301	pciefd_can_writereg(priv, 0, PCIEFD_REG_CAN_TX_DMA_ADDR_H);
302}
303
304static void pciefd_can_ack_rx_dma(struct pciefd_can *priv)
305{
306	/* read value of current IRQ tag and inc it for next one */
307	priv->irq_tag = le32_to_cpu(*(__le32 *)priv->rx_dma_vaddr);
308	priv->irq_tag++;
309	priv->irq_tag &= 0xf;
310
311	/* write the next IRQ tag for this CAN */
312	pciefd_can_writereg(priv, priv->irq_tag, PCIEFD_REG_CAN_RX_CTL_ACK);
313}
314
315/* IRQ handler */
316static irqreturn_t pciefd_irq_handler(int irq, void *arg)
317{
318	struct pciefd_can *priv = arg;
319	struct pciefd_rx_dma *rx_dma = priv->rx_dma_vaddr;
320
321	/* INTA mode only to sync with PCIe transaction */
322	if (!pci_dev_msi_enabled(priv->board->pci_dev))
323		(void)pciefd_sys_readreg(priv->board, PCIEFD_REG_SYS_VER1);
324
325	/* read IRQ status from the first 32-bits of the Rx DMA area */
326	priv->irq_status = le32_to_cpu(rx_dma->irq_status);
327
328	/* check if this (shared) IRQ is for this CAN */
329	if (pciefd_irq_tag(priv->irq_status) != priv->irq_tag)
330		return IRQ_NONE;
331
332	/* handle rx messages (if any) */
333	peak_canfd_handle_msgs_list(&priv->ucan,
334				    rx_dma->msg,
335				    pciefd_irq_rx_cnt(priv->irq_status));
336
337	/* handle tx link interrupt (if any) */
338	if (pciefd_irq_is_lnk(priv->irq_status)) {
339		unsigned long flags;
340
341		spin_lock_irqsave(&priv->tx_lock, flags);
342		priv->tx_pages_free++;
343		spin_unlock_irqrestore(&priv->tx_lock, flags);
344
345		/* wake producer up (only if enough room in echo_skb array) */
346		spin_lock_irqsave(&priv->ucan.echo_lock, flags);
347		if (!priv->ucan.can.echo_skb[priv->ucan.echo_idx])
348			netif_wake_queue(priv->ucan.ndev);
349
350		spin_unlock_irqrestore(&priv->ucan.echo_lock, flags);
351	}
352
353	/* re-enable Rx DMA transfer for this CAN */
354	pciefd_can_ack_rx_dma(priv);
355
356	return IRQ_HANDLED;
357}
358
359static int pciefd_enable_tx_path(struct peak_canfd_priv *ucan)
360{
361	struct pciefd_can *priv = (struct pciefd_can *)ucan;
362	int i;
363
364	/* initialize the Tx pages descriptors */
365	priv->tx_pages_free = PCIEFD_TX_PAGE_COUNT - 1;
366	priv->tx_page_index = 0;
367
368	priv->tx_pages[0].vbase = priv->tx_dma_vaddr;
369	priv->tx_pages[0].lbase = priv->tx_dma_laddr;
370
371	for (i = 0; i < PCIEFD_TX_PAGE_COUNT; i++) {
372		priv->tx_pages[i].offset = 0;
373		priv->tx_pages[i].size = PCIEFD_TX_PAGE_SIZE -
374					 sizeof(struct pciefd_tx_link);
375		if (i) {
376			priv->tx_pages[i].vbase =
377					  priv->tx_pages[i - 1].vbase +
378					  PCIEFD_TX_PAGE_SIZE;
379			priv->tx_pages[i].lbase =
380					  priv->tx_pages[i - 1].lbase +
381					  PCIEFD_TX_PAGE_SIZE;
382		}
383	}
384
385	/* setup Tx DMA addresses into IP core */
386	pciefd_can_setup_tx_dma(priv);
387
388	/* start (TX_RST=0) Tx Path */
389	pciefd_can_writereg(priv, CANFD_CTL_RST_BIT, PCIEFD_REG_CAN_TX_CTL_CLR);
390
391	return 0;
392}
393
394/* board specific CANFD command pre-processing */
395static int pciefd_pre_cmd(struct peak_canfd_priv *ucan)
396{
397	struct pciefd_can *priv = (struct pciefd_can *)ucan;
398	u16 cmd = pucan_cmd_get_opcode(&priv->pucan_cmd);
399	int err;
400
401	/* pre-process command */
402	switch (cmd) {
403	case PUCAN_CMD_NORMAL_MODE:
404	case PUCAN_CMD_LISTEN_ONLY_MODE:
405
406		if (ucan->can.state == CAN_STATE_BUS_OFF)
407			break;
408
409		/* going into operational mode: setup IRQ handler */
410		err = request_irq(priv->ucan.ndev->irq,
411				  pciefd_irq_handler,
412				  IRQF_SHARED,
413				  PCIEFD_DRV_NAME,
414				  priv);
415		if (err)
416			return err;
417
418		/* setup Rx DMA address */
419		pciefd_can_setup_rx_dma(priv);
420
421		/* setup max count of msgs per IRQ */
422		pciefd_can_writereg(priv, (CANFD_CTL_IRQ_TL_DEF) << 8 |
423				    CANFD_CTL_IRQ_CL_DEF,
424				    PCIEFD_REG_CAN_RX_CTL_WRT);
425
426		/* clear DMA RST for Rx (Rx start) */
427		pciefd_can_writereg(priv, CANFD_CTL_RST_BIT,
428				    PCIEFD_REG_CAN_RX_CTL_CLR);
429
430		/* reset timestamps */
431		pciefd_can_writereg(priv, !CANFD_MISC_TS_RST,
432				    PCIEFD_REG_CAN_MISC);
433
434		/* do an initial ACK */
435		pciefd_can_ack_rx_dma(priv);
436
437		/* enable IRQ for this CAN after having set next irq_tag */
438		pciefd_can_writereg(priv, CANFD_CTL_IEN_BIT,
439				    PCIEFD_REG_CAN_RX_CTL_SET);
440
441		/* Tx path will be setup as soon as RX_BARRIER is received */
442		break;
443	default:
444		break;
445	}
446
447	return 0;
448}
449
450/* write a command */
451static int pciefd_write_cmd(struct peak_canfd_priv *ucan)
452{
453	struct pciefd_can *priv = (struct pciefd_can *)ucan;
454	unsigned long flags;
455
456	/* 64-bits command is atomic */
457	spin_lock_irqsave(&priv->board->cmd_lock, flags);
458
459	pciefd_can_writereg(priv, *(u32 *)ucan->cmd_buffer,
460			    PCIEFD_REG_CAN_CMD_PORT_L);
461	pciefd_can_writereg(priv, *(u32 *)(ucan->cmd_buffer + 4),
462			    PCIEFD_REG_CAN_CMD_PORT_H);
463
464	spin_unlock_irqrestore(&priv->board->cmd_lock, flags);
465
466	return 0;
467}
468
469/* board specific CANFD command post-processing */
470static int pciefd_post_cmd(struct peak_canfd_priv *ucan)
471{
472	struct pciefd_can *priv = (struct pciefd_can *)ucan;
473	u16 cmd = pucan_cmd_get_opcode(&priv->pucan_cmd);
474
475	switch (cmd) {
476	case PUCAN_CMD_RESET_MODE:
477
478		if (ucan->can.state == CAN_STATE_STOPPED)
479			break;
480
481		/* controller now in reset mode: */
482
483		/* disable IRQ for this CAN */
484		pciefd_can_writereg(priv, CANFD_CTL_IEN_BIT,
485				    PCIEFD_REG_CAN_RX_CTL_CLR);
486
487		/* stop and reset DMA addresses in Tx/Rx engines */
488		pciefd_can_clear_tx_dma(priv);
489		pciefd_can_clear_rx_dma(priv);
490
491		/* wait for above commands to complete (read cycle) */
492		(void)pciefd_sys_readreg(priv->board, PCIEFD_REG_SYS_VER1);
493
494		free_irq(priv->ucan.ndev->irq, priv);
495
496		ucan->can.state = CAN_STATE_STOPPED;
497
498		break;
499	}
500
501	return 0;
502}
503
504static void *pciefd_alloc_tx_msg(struct peak_canfd_priv *ucan, u16 msg_size,
505				 int *room_left)
506{
507	struct pciefd_can *priv = (struct pciefd_can *)ucan;
508	struct pciefd_page *page = priv->tx_pages + priv->tx_page_index;
509	unsigned long flags;
510	void *msg;
511
512	spin_lock_irqsave(&priv->tx_lock, flags);
513
514	if (page->offset + msg_size > page->size) {
515		struct pciefd_tx_link *lk;
516
517		/* not enough space in this page: try another one */
518		if (!priv->tx_pages_free) {
519			spin_unlock_irqrestore(&priv->tx_lock, flags);
520
521			/* Tx overflow */
522			return NULL;
523		}
524
525		priv->tx_pages_free--;
526
527		/* keep address of the very last free slot of current page */
528		lk = page->vbase + page->offset;
529
530		/* next, move on a new free page */
531		priv->tx_page_index = (priv->tx_page_index + 1) %
532				      PCIEFD_TX_PAGE_COUNT;
533		page = priv->tx_pages + priv->tx_page_index;
534
535		/* put link record to this new page at the end of prev one */
536		lk->size = cpu_to_le16(sizeof(*lk));
537		lk->type = cpu_to_le16(CANFD_MSG_LNK_TX);
538		lk->laddr_lo = cpu_to_le32(page->lbase);
539
540#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
541		lk->laddr_hi = cpu_to_le32(page->lbase >> 32);
542#else
543		lk->laddr_hi = 0;
544#endif
545		/* next msgs will be put from the begininng of this new page */
546		page->offset = 0;
547	}
548
549	*room_left = priv->tx_pages_free * page->size;
550
551	spin_unlock_irqrestore(&priv->tx_lock, flags);
552
553	msg = page->vbase + page->offset;
554
555	/* give back room left in the tx ring */
556	*room_left += page->size - (page->offset + msg_size);
557
558	return msg;
559}
560
561static int pciefd_write_tx_msg(struct peak_canfd_priv *ucan,
562			       struct pucan_tx_msg *msg)
563{
564	struct pciefd_can *priv = (struct pciefd_can *)ucan;
565	struct pciefd_page *page = priv->tx_pages + priv->tx_page_index;
566
567	/* this slot is now reserved for writing the frame */
568	page->offset += le16_to_cpu(msg->size);
569
570	/* tell the board a frame has been written in Tx DMA area */
571	pciefd_can_writereg(priv, 1, PCIEFD_REG_CAN_TX_REQ_ACC);
572
573	return 0;
574}
575
576/* probe for CAN-FD channel #pciefd_board->can_count */
577static int pciefd_can_probe(struct pciefd_board *pciefd)
578{
579	struct net_device *ndev;
580	struct pciefd_can *priv;
581	u32 clk;
582	int err;
583
584	/* allocate the candev object with default isize of echo skbs ring */
585	ndev = alloc_peak_canfd_dev(sizeof(*priv), pciefd->can_count,
586				    PCIEFD_ECHO_SKB_MAX);
587	if (!ndev) {
588		dev_err(&pciefd->pci_dev->dev,
589			"failed to alloc candev object\n");
590		goto failure;
591	}
592
593	priv = netdev_priv(ndev);
594
595	/* fill-in candev private object: */
596
597	/* setup PCIe-FD own callbacks */
598	priv->ucan.pre_cmd = pciefd_pre_cmd;
599	priv->ucan.write_cmd = pciefd_write_cmd;
600	priv->ucan.post_cmd = pciefd_post_cmd;
601	priv->ucan.enable_tx_path = pciefd_enable_tx_path;
602	priv->ucan.alloc_tx_msg = pciefd_alloc_tx_msg;
603	priv->ucan.write_tx_msg = pciefd_write_tx_msg;
604
605	/* setup PCIe-FD own command buffer */
606	priv->ucan.cmd_buffer = &priv->pucan_cmd;
607	priv->ucan.cmd_maxlen = sizeof(priv->pucan_cmd);
608
609	priv->board = pciefd;
610
611	/* CAN config regs block address */
612	priv->reg_base = pciefd->reg_base + PCIEFD_CANX_OFF(priv->ucan.index);
613
614	/* allocate non-cacheable DMA'able 4KB memory area for Rx */
615	priv->rx_dma_vaddr = dmam_alloc_coherent(&pciefd->pci_dev->dev,
616						 PCIEFD_RX_DMA_SIZE,
617						 &priv->rx_dma_laddr,
618						 GFP_KERNEL);
619	if (!priv->rx_dma_vaddr) {
620		dev_err(&pciefd->pci_dev->dev,
621			"Rx dmam_alloc_coherent(%u) failure\n",
622			PCIEFD_RX_DMA_SIZE);
623		goto err_free_candev;
624	}
625
626	/* allocate non-cacheable DMA'able 4KB memory area for Tx */
627	priv->tx_dma_vaddr = dmam_alloc_coherent(&pciefd->pci_dev->dev,
628						 PCIEFD_TX_DMA_SIZE,
629						 &priv->tx_dma_laddr,
630						 GFP_KERNEL);
631	if (!priv->tx_dma_vaddr) {
632		dev_err(&pciefd->pci_dev->dev,
633			"Tx dmam_alloc_coherent(%u) failure\n",
634			PCIEFD_TX_DMA_SIZE);
635		goto err_free_candev;
636	}
637
638	/* CAN clock in RST mode */
639	pciefd_can_writereg(priv, CANFD_MISC_TS_RST, PCIEFD_REG_CAN_MISC);
640
641	/* read current clock value */
642	clk = pciefd_can_readreg(priv, PCIEFD_REG_CAN_CLK_SEL);
643	switch (clk) {
644	case CANFD_CLK_SEL_20MHZ:
645		priv->ucan.can.clock.freq = 20 * 1000 * 1000;
646		break;
647	case CANFD_CLK_SEL_24MHZ:
648		priv->ucan.can.clock.freq = 24 * 1000 * 1000;
649		break;
650	case CANFD_CLK_SEL_30MHZ:
651		priv->ucan.can.clock.freq = 30 * 1000 * 1000;
652		break;
653	case CANFD_CLK_SEL_40MHZ:
654		priv->ucan.can.clock.freq = 40 * 1000 * 1000;
655		break;
656	case CANFD_CLK_SEL_60MHZ:
657		priv->ucan.can.clock.freq = 60 * 1000 * 1000;
658		break;
659	default:
660		pciefd_can_writereg(priv, CANFD_CLK_SEL_80MHZ,
661				    PCIEFD_REG_CAN_CLK_SEL);
662
663		/* fall through */
664	case CANFD_CLK_SEL_80MHZ:
665		priv->ucan.can.clock.freq = 80 * 1000 * 1000;
666		break;
667	}
668
669	ndev->irq = pciefd->pci_dev->irq;
670
671	SET_NETDEV_DEV(ndev, &pciefd->pci_dev->dev);
672
673	err = register_candev(ndev);
674	if (err) {
675		dev_err(&pciefd->pci_dev->dev,
676			"couldn't register CAN device: %d\n", err);
677		goto err_free_candev;
678	}
679
680	spin_lock_init(&priv->tx_lock);
681
682	/* save the object address in the board structure */
683	pciefd->can[pciefd->can_count] = priv;
684
685	dev_info(&pciefd->pci_dev->dev, "%s at reg_base=0x%p irq=%d\n",
686		 ndev->name, priv->reg_base, ndev->irq);
687
688	return 0;
689
690err_free_candev:
691	free_candev(ndev);
692
693failure:
694	return -ENOMEM;
695}
696
697/* remove a CAN-FD channel by releasing all of its resources */
698static void pciefd_can_remove(struct pciefd_can *priv)
699{
700	/* unregister (close) the can device to go back to RST mode first */
701	unregister_candev(priv->ucan.ndev);
702
703	/* finally, free the candev object */
704	free_candev(priv->ucan.ndev);
705}
706
707/* remove all CAN-FD channels by releasing their own resources */
708static void pciefd_can_remove_all(struct pciefd_board *pciefd)
709{
710	while (pciefd->can_count > 0)
711		pciefd_can_remove(pciefd->can[--pciefd->can_count]);
712}
713
714/* probe for the entire device */
715static int peak_pciefd_probe(struct pci_dev *pdev,
716			     const struct pci_device_id *ent)
717{
718	struct pciefd_board *pciefd;
719	int err, can_count;
720	u16 sub_sys_id;
721	u8 hw_ver_major;
722	u8 hw_ver_minor;
723	u8 hw_ver_sub;
724	u32 v2;
725
726	err = pci_enable_device(pdev);
727	if (err)
728		return err;
729	err = pci_request_regions(pdev, PCIEFD_DRV_NAME);
730	if (err)
731		goto err_disable_pci;
732
733	/* the number of channels depends on sub-system id */
734	err = pci_read_config_word(pdev, PCI_SUBSYSTEM_ID, &sub_sys_id);
735	if (err)
736		goto err_release_regions;
737
738	dev_dbg(&pdev->dev, "probing device %04x:%04x:%04x\n",
739		pdev->vendor, pdev->device, sub_sys_id);
740
741	if (sub_sys_id >= 0x0012)
742		can_count = 4;
743	else if (sub_sys_id >= 0x0010)
744		can_count = 3;
745	else if (sub_sys_id >= 0x0004)
746		can_count = 2;
747	else
748		can_count = 1;
749
750	/* allocate board structure object */
751	pciefd = devm_kzalloc(&pdev->dev, struct_size(pciefd, can, can_count),
752			      GFP_KERNEL);
753	if (!pciefd) {
754		err = -ENOMEM;
755		goto err_release_regions;
756	}
757
758	/* initialize the board structure */
759	pciefd->pci_dev = pdev;
760	spin_lock_init(&pciefd->cmd_lock);
761
762	/* save the PCI BAR0 virtual address for further system regs access */
763	pciefd->reg_base = pci_iomap(pdev, 0, PCIEFD_BAR0_SIZE);
764	if (!pciefd->reg_base) {
765		dev_err(&pdev->dev, "failed to map PCI resource #0\n");
766		err = -ENOMEM;
767		goto err_release_regions;
768	}
769
770	/* read the firmware version number */
771	v2 = pciefd_sys_readreg(pciefd, PCIEFD_REG_SYS_VER2);
772
773	hw_ver_major = (v2 & 0x0000f000) >> 12;
774	hw_ver_minor = (v2 & 0x00000f00) >> 8;
775	hw_ver_sub = (v2 & 0x000000f0) >> 4;
776
777	dev_info(&pdev->dev,
778		 "%ux CAN-FD PCAN-PCIe FPGA v%u.%u.%u:\n", can_count,
779		 hw_ver_major, hw_ver_minor, hw_ver_sub);
780
781#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
782	/* FW < v3.3.0 DMA logic doesn't handle correctly the mix of 32-bit and
783	 * 64-bit logical addresses: this workaround forces usage of 32-bit
784	 * DMA addresses only when such a fw is detected.
785	 */
786	if (PCIEFD_FW_VERSION(hw_ver_major, hw_ver_minor, hw_ver_sub) <
787	    PCIEFD_FW_VERSION(3, 3, 0)) {
788		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
789		if (err)
790			dev_warn(&pdev->dev,
791				 "warning: can't set DMA mask %llxh (err %d)\n",
792				 DMA_BIT_MASK(32), err);
793	}
794#endif
795
796	/* stop system clock */
797	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_CLK_EN,
798			    PCIEFD_REG_SYS_CTL_CLR);
799
800	pci_set_master(pdev);
801
802	/* create now the corresponding channels objects */
803	while (pciefd->can_count < can_count) {
804		err = pciefd_can_probe(pciefd);
805		if (err)
806			goto err_free_canfd;
807
808		pciefd->can_count++;
809	}
810
811	/* set system timestamps counter in RST mode */
812	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_TS_RST,
813			    PCIEFD_REG_SYS_CTL_SET);
814
815	/* wait a bit (read cycle) */
816	(void)pciefd_sys_readreg(pciefd, PCIEFD_REG_SYS_VER1);
817
818	/* free all clocks */
819	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_TS_RST,
820			    PCIEFD_REG_SYS_CTL_CLR);
821
822	/* start system clock */
823	pciefd_sys_writereg(pciefd, PCIEFD_SYS_CTL_CLK_EN,
824			    PCIEFD_REG_SYS_CTL_SET);
825
826	/* remember the board structure address in the device user data */
827	pci_set_drvdata(pdev, pciefd);
828
829	return 0;
830
831err_free_canfd:
832	pciefd_can_remove_all(pciefd);
833
834	pci_iounmap(pdev, pciefd->reg_base);
835
836err_release_regions:
837	pci_release_regions(pdev);
838
839err_disable_pci:
840	pci_disable_device(pdev);
841
842	/* pci_xxx_config_word() return positive PCIBIOS_xxx error codes while
843	 * the probe() function must return a negative errno in case of failure
844	 * (err is unchanged if negative) */
845	return pcibios_err_to_errno(err);
846}
847
848/* free the board structure object, as well as its resources: */
849static void peak_pciefd_remove(struct pci_dev *pdev)
850{
851	struct pciefd_board *pciefd = pci_get_drvdata(pdev);
852
853	/* release CAN-FD channels resources */
854	pciefd_can_remove_all(pciefd);
855
856	pci_iounmap(pdev, pciefd->reg_base);
857
858	pci_release_regions(pdev);
859	pci_disable_device(pdev);
860}
861
862static struct pci_driver peak_pciefd_driver = {
863	.name = PCIEFD_DRV_NAME,
864	.id_table = peak_pciefd_tbl,
865	.probe = peak_pciefd_probe,
866	.remove = peak_pciefd_remove,
867};
868
869module_pci_driver(peak_pciefd_driver);