xref: /openbmc/linux/drivers/net/wan/ixp4xx_hss.c (revision d5771670)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Intel IXP4xx HSS (synchronous serial port) driver for Linux
4  *
5  * Copyright (C) 2007-2008 Krzysztof Hałasa <khc@pm.waw.pl>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/module.h>
11 #include <linux/bitops.h>
12 #include <linux/cdev.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/dmapool.h>
15 #include <linux/fs.h>
16 #include <linux/hdlc.h>
17 #include <linux/io.h>
18 #include <linux/kernel.h>
19 #include <linux/mfd/syscon.h>
20 #include <linux/platform_device.h>
21 #include <linux/poll.h>
22 #include <linux/regmap.h>
23 #include <linux/slab.h>
24 #include <linux/gpio/consumer.h>
25 #include <linux/of.h>
26 #include <linux/soc/ixp4xx/npe.h>
27 #include <linux/soc/ixp4xx/qmgr.h>
28 #include <linux/soc/ixp4xx/cpu.h>
29 
30 /* This is what all IXP4xx platforms we know uses, if more frequencies
31  * are needed, we need to migrate to the clock framework.
32  */
33 #define IXP4XX_TIMER_FREQ	66666000
34 
35 #define DEBUG_DESC		0
36 #define DEBUG_RX		0
37 #define DEBUG_TX		0
38 #define DEBUG_PKT_BYTES		0
39 #define DEBUG_CLOSE		0
40 
41 #define DRV_NAME		"ixp4xx_hss"
42 
43 #define PKT_EXTRA_FLAGS		0 /* orig 1 */
44 #define PKT_NUM_PIPES		1 /* 1, 2 or 4 */
45 #define PKT_PIPE_FIFO_SIZEW	4 /* total 4 dwords per HSS */
46 
47 #define RX_DESCS		16 /* also length of all RX queues */
48 #define TX_DESCS		16 /* also length of all TX queues */
49 
50 #define POOL_ALLOC_SIZE		(sizeof(struct desc) * (RX_DESCS + TX_DESCS))
51 #define RX_SIZE			(HDLC_MAX_MRU + 4) /* NPE needs more space */
52 #define MAX_CLOSE_WAIT		1000 /* microseconds */
53 #define HSS_COUNT		2
54 #define FRAME_SIZE		256 /* doesn't matter at this point */
55 #define FRAME_OFFSET		0
56 #define MAX_CHANNELS		(FRAME_SIZE / 8)
57 
58 #define NAPI_WEIGHT		16
59 
60 /* Queue IDs */
61 #define HSS0_PKT_RX_QUEUE	13	/* orig size = 32 dwords */
62 #define HSS0_PKT_TX0_QUEUE	14	/* orig size = 16 dwords */
63 #define HSS0_PKT_TX1_QUEUE	15
64 #define HSS0_PKT_TX2_QUEUE	16
65 #define HSS0_PKT_TX3_QUEUE	17
66 #define HSS0_PKT_RXFREE0_QUEUE	18	/* orig size = 16 dwords */
67 #define HSS0_PKT_RXFREE1_QUEUE	19
68 #define HSS0_PKT_RXFREE2_QUEUE	20
69 #define HSS0_PKT_RXFREE3_QUEUE	21
70 #define HSS0_PKT_TXDONE_QUEUE	22	/* orig size = 64 dwords */
71 
72 #define HSS1_PKT_RX_QUEUE	0
73 #define HSS1_PKT_TX0_QUEUE	5
74 #define HSS1_PKT_TX1_QUEUE	6
75 #define HSS1_PKT_TX2_QUEUE	7
76 #define HSS1_PKT_TX3_QUEUE	8
77 #define HSS1_PKT_RXFREE0_QUEUE	1
78 #define HSS1_PKT_RXFREE1_QUEUE	2
79 #define HSS1_PKT_RXFREE2_QUEUE	3
80 #define HSS1_PKT_RXFREE3_QUEUE	4
81 #define HSS1_PKT_TXDONE_QUEUE	9
82 
83 #define NPE_PKT_MODE_HDLC		0
84 #define NPE_PKT_MODE_RAW		1
85 #define NPE_PKT_MODE_56KMODE		2
86 #define NPE_PKT_MODE_56KENDIAN_MSB	4
87 
88 /* PKT_PIPE_HDLC_CFG_WRITE flags */
89 #define PKT_HDLC_IDLE_ONES		0x1 /* default = flags */
90 #define PKT_HDLC_CRC_32			0x2 /* default = CRC-16 */
91 #define PKT_HDLC_MSB_ENDIAN		0x4 /* default = LE */
92 
93 /* hss_config, PCRs */
94 /* Frame sync sampling, default = active low */
95 #define PCR_FRM_SYNC_ACTIVE_HIGH	0x40000000
96 #define PCR_FRM_SYNC_FALLINGEDGE	0x80000000
97 #define PCR_FRM_SYNC_RISINGEDGE		0xC0000000
98 
99 /* Frame sync pin: input (default) or output generated off a given clk edge */
100 #define PCR_FRM_SYNC_OUTPUT_FALLING	0x20000000
101 #define PCR_FRM_SYNC_OUTPUT_RISING	0x30000000
102 
103 /* Frame and data clock sampling on edge, default = falling */
104 #define PCR_FCLK_EDGE_RISING		0x08000000
105 #define PCR_DCLK_EDGE_RISING		0x04000000
106 
107 /* Clock direction, default = input */
108 #define PCR_SYNC_CLK_DIR_OUTPUT		0x02000000
109 
110 /* Generate/Receive frame pulses, default = enabled */
111 #define PCR_FRM_PULSE_DISABLED		0x01000000
112 
113  /* Data rate is full (default) or half the configured clk speed */
114 #define PCR_HALF_CLK_RATE		0x00200000
115 
116 /* Invert data between NPE and HSS FIFOs? (default = no) */
117 #define PCR_DATA_POLARITY_INVERT	0x00100000
118 
119 /* TX/RX endianness, default = LSB */
120 #define PCR_MSB_ENDIAN			0x00080000
121 
122 /* Normal (default) / open drain mode (TX only) */
123 #define PCR_TX_PINS_OPEN_DRAIN		0x00040000
124 
125 /* No framing bit transmitted and expected on RX? (default = framing bit) */
126 #define PCR_SOF_NO_FBIT			0x00020000
127 
128 /* Drive data pins? */
129 #define PCR_TX_DATA_ENABLE		0x00010000
130 
131 /* Voice 56k type: drive the data pins low (default), high, high Z */
132 #define PCR_TX_V56K_HIGH		0x00002000
133 #define PCR_TX_V56K_HIGH_IMP		0x00004000
134 
135 /* Unassigned type: drive the data pins low (default), high, high Z */
136 #define PCR_TX_UNASS_HIGH		0x00000800
137 #define PCR_TX_UNASS_HIGH_IMP		0x00001000
138 
139 /* T1 @ 1.544MHz only: Fbit dictated in FIFO (default) or high Z */
140 #define PCR_TX_FB_HIGH_IMP		0x00000400
141 
142 /* 56k data endiannes - which bit unused: high (default) or low */
143 #define PCR_TX_56KE_BIT_0_UNUSED	0x00000200
144 
145 /* 56k data transmission type: 32/8 bit data (default) or 56K data */
146 #define PCR_TX_56KS_56K_DATA		0x00000100
147 
148 /* hss_config, cCR */
149 /* Number of packetized clients, default = 1 */
150 #define CCR_NPE_HFIFO_2_HDLC		0x04000000
151 #define CCR_NPE_HFIFO_3_OR_4HDLC	0x08000000
152 
153 /* default = no loopback */
154 #define CCR_LOOPBACK			0x02000000
155 
156 /* HSS number, default = 0 (first) */
157 #define CCR_SECOND_HSS			0x01000000
158 
159 /* hss_config, clkCR: main:10, num:10, denom:12 */
160 #define CLK42X_SPEED_EXP	((0x3FF << 22) | (2 << 12) |   15) /*65 KHz*/
161 
162 #define CLK42X_SPEED_512KHZ	((130 << 22) | (2 << 12) |   15)
163 #define CLK42X_SPEED_1536KHZ	((43 << 22) | (18 << 12) |   47)
164 #define CLK42X_SPEED_1544KHZ	((43 << 22) | (33 << 12) |  192)
165 #define CLK42X_SPEED_2048KHZ	((32 << 22) | (34 << 12) |   63)
166 #define CLK42X_SPEED_4096KHZ	((16 << 22) | (34 << 12) |  127)
167 #define CLK42X_SPEED_8192KHZ	((8 << 22) | (34 << 12) |  255)
168 
169 #define CLK46X_SPEED_512KHZ	((130 << 22) | (24 << 12) |  127)
170 #define CLK46X_SPEED_1536KHZ	((43 << 22) | (152 << 12) |  383)
171 #define CLK46X_SPEED_1544KHZ	((43 << 22) | (66 << 12) |  385)
172 #define CLK46X_SPEED_2048KHZ	((32 << 22) | (280 << 12) |  511)
173 #define CLK46X_SPEED_4096KHZ	((16 << 22) | (280 << 12) | 1023)
174 #define CLK46X_SPEED_8192KHZ	((8 << 22) | (280 << 12) | 2047)
175 
176 /* HSS_CONFIG_CLOCK_CR register consists of 3 parts:
177  *     A (10 bits), B (10 bits) and C (12 bits).
178  * IXP42x HSS clock generator operation (verified with an oscilloscope):
179  * Each clock bit takes 7.5 ns (1 / 133.xx MHz).
180  * The clock sequence consists of (C - B) states of 0s and 1s, each state is
181  * A bits wide. It's followed by (B + 1) states of 0s and 1s, each state is
182  * (A + 1) bits wide.
183  *
184  * The resulting average clock frequency (assuming 33.333 MHz oscillator) is:
185  * freq = 66.666 MHz / (A + (B + 1) / (C + 1))
186  * minimum freq = 66.666 MHz / (A + 1)
187  * maximum freq = 66.666 MHz / A
188  *
189  * Example: A = 2, B = 2, C = 7, CLOCK_CR register = 2 << 22 | 2 << 12 | 7
190  * freq = 66.666 MHz / (2 + (2 + 1) / (7 + 1)) = 28.07 MHz (Mb/s).
191  * The clock sequence is: 1100110011 (5 doubles) 000111000 (3 triples).
192  * The sequence takes (C - B) * A + (B + 1) * (A + 1) = 5 * 2 + 3 * 3 bits
193  * = 19 bits (each 7.5 ns long) = 142.5 ns (then the sequence repeats).
194  * The sequence consists of 4 complete clock periods, thus the average
195  * frequency (= clock rate) is 4 / 142.5 ns = 28.07 MHz (Mb/s).
196  * (max specified clock rate for IXP42x HSS is 8.192 Mb/s).
197  */
198 
199 /* hss_config, LUT entries */
200 #define TDMMAP_UNASSIGNED	0
201 #define TDMMAP_HDLC		1	/* HDLC - packetized */
202 #define TDMMAP_VOICE56K		2	/* Voice56K - 7-bit channelized */
203 #define TDMMAP_VOICE64K		3	/* Voice64K - 8-bit channelized */
204 
205 /* offsets into HSS config */
206 #define HSS_CONFIG_TX_PCR	0x00 /* port configuration registers */
207 #define HSS_CONFIG_RX_PCR	0x04
208 #define HSS_CONFIG_CORE_CR	0x08 /* loopback control, HSS# */
209 #define HSS_CONFIG_CLOCK_CR	0x0C /* clock generator control */
210 #define HSS_CONFIG_TX_FCR	0x10 /* frame configuration registers */
211 #define HSS_CONFIG_RX_FCR	0x14
212 #define HSS_CONFIG_TX_LUT	0x18 /* channel look-up tables */
213 #define HSS_CONFIG_RX_LUT	0x38
214 
215 /* NPE command codes */
216 /* writes the ConfigWord value to the location specified by offset */
217 #define PORT_CONFIG_WRITE		0x40
218 
219 /* triggers the NPE to load the contents of the configuration table */
220 #define PORT_CONFIG_LOAD		0x41
221 
222 /* triggers the NPE to return an HssErrorReadResponse message */
223 #define PORT_ERROR_READ			0x42
224 
225 /* triggers the NPE to reset internal status and enable the HssPacketized
226  * operation for the flow specified by pPipe
227  */
228 #define PKT_PIPE_FLOW_ENABLE		0x50
229 #define PKT_PIPE_FLOW_DISABLE		0x51
230 #define PKT_NUM_PIPES_WRITE		0x52
231 #define PKT_PIPE_FIFO_SIZEW_WRITE	0x53
232 #define PKT_PIPE_HDLC_CFG_WRITE		0x54
233 #define PKT_PIPE_IDLE_PATTERN_WRITE	0x55
234 #define PKT_PIPE_RX_SIZE_WRITE		0x56
235 #define PKT_PIPE_MODE_WRITE		0x57
236 
237 /* HDLC packet status values - desc->status */
238 #define ERR_SHUTDOWN		1 /* stop or shutdown occurrence */
239 #define ERR_HDLC_ALIGN		2 /* HDLC alignment error */
240 #define ERR_HDLC_FCS		3 /* HDLC Frame Check Sum error */
241 #define ERR_RXFREE_Q_EMPTY	4 /* RX-free queue became empty while receiving
242 				   * this packet (if buf_len < pkt_len)
243 				   */
244 #define ERR_HDLC_TOO_LONG	5 /* HDLC frame size too long */
245 #define ERR_HDLC_ABORT		6 /* abort sequence received */
246 #define ERR_DISCONNECTING	7 /* disconnect is in progress */
247 
248 #ifdef __ARMEB__
249 typedef struct sk_buff buffer_t;
250 #define free_buffer dev_kfree_skb
251 #define free_buffer_irq dev_consume_skb_irq
252 #else
253 typedef void buffer_t;
254 #define free_buffer kfree
255 #define free_buffer_irq kfree
256 #endif
257 
258 struct port {
259 	struct device *dev;
260 	struct npe *npe;
261 	unsigned int txreadyq;
262 	unsigned int rxtrigq;
263 	unsigned int rxfreeq;
264 	unsigned int rxq;
265 	unsigned int txq;
266 	unsigned int txdoneq;
267 	struct gpio_desc *cts;
268 	struct gpio_desc *rts;
269 	struct gpio_desc *dcd;
270 	struct gpio_desc *dtr;
271 	struct gpio_desc *clk_internal;
272 	struct net_device *netdev;
273 	struct napi_struct napi;
274 	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
275 	struct desc *desc_tab;	/* coherent */
276 	dma_addr_t desc_tab_phys;
277 	unsigned int id;
278 	unsigned int clock_type, clock_rate, loopback;
279 	unsigned int initialized, carrier;
280 	u8 hdlc_cfg;
281 	u32 clock_reg;
282 };
283 
284 /* NPE message structure */
285 struct msg {
286 #ifdef __ARMEB__
287 	u8 cmd, unused, hss_port, index;
288 	union {
289 		struct { u8 data8a, data8b, data8c, data8d; };
290 		struct { u16 data16a, data16b; };
291 		struct { u32 data32; };
292 	};
293 #else
294 	u8 index, hss_port, unused, cmd;
295 	union {
296 		struct { u8 data8d, data8c, data8b, data8a; };
297 		struct { u16 data16b, data16a; };
298 		struct { u32 data32; };
299 	};
300 #endif
301 };
302 
303 /* HDLC packet descriptor */
304 struct desc {
305 	u32 next;		/* pointer to next buffer, unused */
306 
307 #ifdef __ARMEB__
308 	u16 buf_len;		/* buffer length */
309 	u16 pkt_len;		/* packet length */
310 	u32 data;		/* pointer to data buffer in RAM */
311 	u8 status;
312 	u8 error_count;
313 	u16 __reserved;
314 #else
315 	u16 pkt_len;		/* packet length */
316 	u16 buf_len;		/* buffer length */
317 	u32 data;		/* pointer to data buffer in RAM */
318 	u16 __reserved;
319 	u8 error_count;
320 	u8 status;
321 #endif
322 	u32 __reserved1[4];
323 };
324 
325 #define rx_desc_phys(port, n)	((port)->desc_tab_phys +		\
326 				 (n) * sizeof(struct desc))
327 #define rx_desc_ptr(port, n)	(&(port)->desc_tab[n])
328 
329 #define tx_desc_phys(port, n)	((port)->desc_tab_phys +		\
330 				 ((n) + RX_DESCS) * sizeof(struct desc))
331 #define tx_desc_ptr(port, n)	(&(port)->desc_tab[(n) + RX_DESCS])
332 
333 /*****************************************************************************
334  * global variables
335  ****************************************************************************/
336 
337 static int ports_open;
338 static struct dma_pool *dma_pool;
339 static DEFINE_SPINLOCK(npe_lock);
340 
341 /*****************************************************************************
342  * utility functions
343  ****************************************************************************/
344 
345 static inline struct port *dev_to_port(struct net_device *dev)
346 {
347 	return dev_to_hdlc(dev)->priv;
348 }
349 
350 #ifndef __ARMEB__
351 static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
352 {
353 	int i;
354 
355 	for (i = 0; i < cnt; i++)
356 		dest[i] = swab32(src[i]);
357 }
358 #endif
359 
360 /*****************************************************************************
361  * HSS access
362  ****************************************************************************/
363 
364 static void hss_npe_send(struct port *port, struct msg *msg, const char *what)
365 {
366 	u32 *val = (u32 *)msg;
367 
368 	if (npe_send_message(port->npe, msg, what)) {
369 		pr_crit("HSS-%i: unable to send command [%08X:%08X] to %s\n",
370 			port->id, val[0], val[1], npe_name(port->npe));
371 		BUG();
372 	}
373 }
374 
375 static void hss_config_set_lut(struct port *port)
376 {
377 	struct msg msg;
378 	int ch;
379 
380 	memset(&msg, 0, sizeof(msg));
381 	msg.cmd = PORT_CONFIG_WRITE;
382 	msg.hss_port = port->id;
383 
384 	for (ch = 0; ch < MAX_CHANNELS; ch++) {
385 		msg.data32 >>= 2;
386 		msg.data32 |= TDMMAP_HDLC << 30;
387 
388 		if (ch % 16 == 15) {
389 			msg.index = HSS_CONFIG_TX_LUT + ((ch / 4) & ~3);
390 			hss_npe_send(port, &msg, "HSS_SET_TX_LUT");
391 
392 			msg.index += HSS_CONFIG_RX_LUT - HSS_CONFIG_TX_LUT;
393 			hss_npe_send(port, &msg, "HSS_SET_RX_LUT");
394 		}
395 	}
396 }
397 
398 static void hss_config(struct port *port)
399 {
400 	struct msg msg;
401 
402 	memset(&msg, 0, sizeof(msg));
403 	msg.cmd = PORT_CONFIG_WRITE;
404 	msg.hss_port = port->id;
405 	msg.index = HSS_CONFIG_TX_PCR;
406 	msg.data32 = PCR_FRM_PULSE_DISABLED | PCR_MSB_ENDIAN |
407 		PCR_TX_DATA_ENABLE | PCR_SOF_NO_FBIT;
408 	if (port->clock_type == CLOCK_INT)
409 		msg.data32 |= PCR_SYNC_CLK_DIR_OUTPUT;
410 	hss_npe_send(port, &msg, "HSS_SET_TX_PCR");
411 
412 	msg.index = HSS_CONFIG_RX_PCR;
413 	msg.data32 ^= PCR_TX_DATA_ENABLE | PCR_DCLK_EDGE_RISING;
414 	hss_npe_send(port, &msg, "HSS_SET_RX_PCR");
415 
416 	memset(&msg, 0, sizeof(msg));
417 	msg.cmd = PORT_CONFIG_WRITE;
418 	msg.hss_port = port->id;
419 	msg.index = HSS_CONFIG_CORE_CR;
420 	msg.data32 = (port->loopback ? CCR_LOOPBACK : 0) |
421 		(port->id ? CCR_SECOND_HSS : 0);
422 	hss_npe_send(port, &msg, "HSS_SET_CORE_CR");
423 
424 	memset(&msg, 0, sizeof(msg));
425 	msg.cmd = PORT_CONFIG_WRITE;
426 	msg.hss_port = port->id;
427 	msg.index = HSS_CONFIG_CLOCK_CR;
428 	msg.data32 = port->clock_reg;
429 	hss_npe_send(port, &msg, "HSS_SET_CLOCK_CR");
430 
431 	memset(&msg, 0, sizeof(msg));
432 	msg.cmd = PORT_CONFIG_WRITE;
433 	msg.hss_port = port->id;
434 	msg.index = HSS_CONFIG_TX_FCR;
435 	msg.data16a = FRAME_OFFSET;
436 	msg.data16b = FRAME_SIZE - 1;
437 	hss_npe_send(port, &msg, "HSS_SET_TX_FCR");
438 
439 	memset(&msg, 0, sizeof(msg));
440 	msg.cmd = PORT_CONFIG_WRITE;
441 	msg.hss_port = port->id;
442 	msg.index = HSS_CONFIG_RX_FCR;
443 	msg.data16a = FRAME_OFFSET;
444 	msg.data16b = FRAME_SIZE - 1;
445 	hss_npe_send(port, &msg, "HSS_SET_RX_FCR");
446 
447 	hss_config_set_lut(port);
448 
449 	memset(&msg, 0, sizeof(msg));
450 	msg.cmd = PORT_CONFIG_LOAD;
451 	msg.hss_port = port->id;
452 	hss_npe_send(port, &msg, "HSS_LOAD_CONFIG");
453 
454 	if (npe_recv_message(port->npe, &msg, "HSS_LOAD_CONFIG") ||
455 	    /* HSS_LOAD_CONFIG for port #1 returns port_id = #4 */
456 	    msg.cmd != PORT_CONFIG_LOAD || msg.data32) {
457 		pr_crit("HSS-%i: HSS_LOAD_CONFIG failed\n", port->id);
458 		BUG();
459 	}
460 
461 	/* HDLC may stop working without this - check FIXME */
462 	npe_recv_message(port->npe, &msg, "FLUSH_IT");
463 }
464 
465 static void hss_set_hdlc_cfg(struct port *port)
466 {
467 	struct msg msg;
468 
469 	memset(&msg, 0, sizeof(msg));
470 	msg.cmd = PKT_PIPE_HDLC_CFG_WRITE;
471 	msg.hss_port = port->id;
472 	msg.data8a = port->hdlc_cfg; /* rx_cfg */
473 	msg.data8b = port->hdlc_cfg | (PKT_EXTRA_FLAGS << 3); /* tx_cfg */
474 	hss_npe_send(port, &msg, "HSS_SET_HDLC_CFG");
475 }
476 
477 static u32 hss_get_status(struct port *port)
478 {
479 	struct msg msg;
480 
481 	memset(&msg, 0, sizeof(msg));
482 	msg.cmd = PORT_ERROR_READ;
483 	msg.hss_port = port->id;
484 	hss_npe_send(port, &msg, "PORT_ERROR_READ");
485 	if (npe_recv_message(port->npe, &msg, "PORT_ERROR_READ")) {
486 		pr_crit("HSS-%i: unable to read HSS status\n", port->id);
487 		BUG();
488 	}
489 
490 	return msg.data32;
491 }
492 
493 static void hss_start_hdlc(struct port *port)
494 {
495 	struct msg msg;
496 
497 	memset(&msg, 0, sizeof(msg));
498 	msg.cmd = PKT_PIPE_FLOW_ENABLE;
499 	msg.hss_port = port->id;
500 	msg.data32 = 0;
501 	hss_npe_send(port, &msg, "HSS_ENABLE_PKT_PIPE");
502 }
503 
504 static void hss_stop_hdlc(struct port *port)
505 {
506 	struct msg msg;
507 
508 	memset(&msg, 0, sizeof(msg));
509 	msg.cmd = PKT_PIPE_FLOW_DISABLE;
510 	msg.hss_port = port->id;
511 	hss_npe_send(port, &msg, "HSS_DISABLE_PKT_PIPE");
512 	hss_get_status(port); /* make sure it's halted */
513 }
514 
515 static int hss_load_firmware(struct port *port)
516 {
517 	struct msg msg;
518 	int err;
519 
520 	if (port->initialized)
521 		return 0;
522 
523 	if (!npe_running(port->npe)) {
524 		err = npe_load_firmware(port->npe, npe_name(port->npe),
525 					port->dev);
526 		if (err)
527 			return err;
528 	}
529 
530 	/* HDLC mode configuration */
531 	memset(&msg, 0, sizeof(msg));
532 	msg.cmd = PKT_NUM_PIPES_WRITE;
533 	msg.hss_port = port->id;
534 	msg.data8a = PKT_NUM_PIPES;
535 	hss_npe_send(port, &msg, "HSS_SET_PKT_PIPES");
536 
537 	msg.cmd = PKT_PIPE_FIFO_SIZEW_WRITE;
538 	msg.data8a = PKT_PIPE_FIFO_SIZEW;
539 	hss_npe_send(port, &msg, "HSS_SET_PKT_FIFO");
540 
541 	msg.cmd = PKT_PIPE_MODE_WRITE;
542 	msg.data8a = NPE_PKT_MODE_HDLC;
543 	/* msg.data8b = inv_mask */
544 	/* msg.data8c = or_mask */
545 	hss_npe_send(port, &msg, "HSS_SET_PKT_MODE");
546 
547 	msg.cmd = PKT_PIPE_RX_SIZE_WRITE;
548 	msg.data16a = HDLC_MAX_MRU; /* including CRC */
549 	hss_npe_send(port, &msg, "HSS_SET_PKT_RX_SIZE");
550 
551 	msg.cmd = PKT_PIPE_IDLE_PATTERN_WRITE;
552 	msg.data32 = 0x7F7F7F7F; /* ??? FIXME */
553 	hss_npe_send(port, &msg, "HSS_SET_PKT_IDLE");
554 
555 	port->initialized = 1;
556 	return 0;
557 }
558 
559 /*****************************************************************************
560  * packetized (HDLC) operation
561  ****************************************************************************/
562 
563 static inline void debug_pkt(struct net_device *dev, const char *func,
564 			     u8 *data, int len)
565 {
566 #if DEBUG_PKT_BYTES
567 	int i;
568 
569 	printk(KERN_DEBUG "%s: %s(%i)", dev->name, func, len);
570 	for (i = 0; i < len; i++) {
571 		if (i >= DEBUG_PKT_BYTES)
572 			break;
573 		printk("%s%02X", !(i % 4) ? " " : "", data[i]);
574 	}
575 	printk("\n");
576 #endif
577 }
578 
579 static inline void debug_desc(u32 phys, struct desc *desc)
580 {
581 #if DEBUG_DESC
582 	printk(KERN_DEBUG "%X: %X %3X %3X %08X %X %X\n",
583 	       phys, desc->next, desc->buf_len, desc->pkt_len,
584 	       desc->data, desc->status, desc->error_count);
585 #endif
586 }
587 
588 static inline int queue_get_desc(unsigned int queue, struct port *port,
589 				 int is_tx)
590 {
591 	u32 phys, tab_phys, n_desc;
592 	struct desc *tab;
593 
594 	phys = qmgr_get_entry(queue);
595 	if (!phys)
596 		return -1;
597 
598 	BUG_ON(phys & 0x1F);
599 	tab_phys = is_tx ? tx_desc_phys(port, 0) : rx_desc_phys(port, 0);
600 	tab = is_tx ? tx_desc_ptr(port, 0) : rx_desc_ptr(port, 0);
601 	n_desc = (phys - tab_phys) / sizeof(struct desc);
602 	BUG_ON(n_desc >= (is_tx ? TX_DESCS : RX_DESCS));
603 	debug_desc(phys, &tab[n_desc]);
604 	BUG_ON(tab[n_desc].next);
605 	return n_desc;
606 }
607 
608 static inline void queue_put_desc(unsigned int queue, u32 phys,
609 				  struct desc *desc)
610 {
611 	debug_desc(phys, desc);
612 	BUG_ON(phys & 0x1F);
613 	qmgr_put_entry(queue, phys);
614 	/* Don't check for queue overflow here, we've allocated sufficient
615 	 * length and queues >= 32 don't support this check anyway.
616 	 */
617 }
618 
619 static inline void dma_unmap_tx(struct port *port, struct desc *desc)
620 {
621 #ifdef __ARMEB__
622 	dma_unmap_single(&port->netdev->dev, desc->data,
623 			 desc->buf_len, DMA_TO_DEVICE);
624 #else
625 	dma_unmap_single(&port->netdev->dev, desc->data & ~3,
626 			 ALIGN((desc->data & 3) + desc->buf_len, 4),
627 			 DMA_TO_DEVICE);
628 #endif
629 }
630 
631 static void hss_hdlc_set_carrier(void *pdev, int carrier)
632 {
633 	struct net_device *netdev = pdev;
634 	struct port *port = dev_to_port(netdev);
635 	unsigned long flags;
636 
637 	spin_lock_irqsave(&npe_lock, flags);
638 	port->carrier = carrier;
639 	if (!port->loopback) {
640 		if (carrier)
641 			netif_carrier_on(netdev);
642 		else
643 			netif_carrier_off(netdev);
644 	}
645 	spin_unlock_irqrestore(&npe_lock, flags);
646 }
647 
648 static void hss_hdlc_rx_irq(void *pdev)
649 {
650 	struct net_device *dev = pdev;
651 	struct port *port = dev_to_port(dev);
652 
653 #if DEBUG_RX
654 	printk(KERN_DEBUG "%s: hss_hdlc_rx_irq\n", dev->name);
655 #endif
656 	qmgr_disable_irq(port->rxq);
657 	napi_schedule(&port->napi);
658 }
659 
660 static int hss_hdlc_poll(struct napi_struct *napi, int budget)
661 {
662 	struct port *port = container_of(napi, struct port, napi);
663 	struct net_device *dev = port->netdev;
664 	unsigned int rxq = port->rxq;
665 	unsigned int rxfreeq = port->rxfreeq;
666 	int received = 0;
667 
668 #if DEBUG_RX
669 	printk(KERN_DEBUG "%s: hss_hdlc_poll\n", dev->name);
670 #endif
671 
672 	while (received < budget) {
673 		struct sk_buff *skb;
674 		struct desc *desc;
675 		int n;
676 #ifdef __ARMEB__
677 		struct sk_buff *temp;
678 		u32 phys;
679 #endif
680 
681 		n = queue_get_desc(rxq, port, 0);
682 		if (n < 0) {
683 #if DEBUG_RX
684 			printk(KERN_DEBUG "%s: hss_hdlc_poll"
685 			       " napi_complete\n", dev->name);
686 #endif
687 			napi_complete(napi);
688 			qmgr_enable_irq(rxq);
689 			if (!qmgr_stat_empty(rxq) &&
690 			    napi_reschedule(napi)) {
691 #if DEBUG_RX
692 				printk(KERN_DEBUG "%s: hss_hdlc_poll"
693 				       " napi_reschedule succeeded\n",
694 				       dev->name);
695 #endif
696 				qmgr_disable_irq(rxq);
697 				continue;
698 			}
699 #if DEBUG_RX
700 			printk(KERN_DEBUG "%s: hss_hdlc_poll all done\n",
701 			       dev->name);
702 #endif
703 			return received; /* all work done */
704 		}
705 
706 		desc = rx_desc_ptr(port, n);
707 #if 0 /* FIXME - error_count counts modulo 256, perhaps we should use it */
708 		if (desc->error_count)
709 			printk(KERN_DEBUG "%s: hss_hdlc_poll status 0x%02X"
710 			       " errors %u\n", dev->name, desc->status,
711 			       desc->error_count);
712 #endif
713 		skb = NULL;
714 		switch (desc->status) {
715 		case 0:
716 #ifdef __ARMEB__
717 			skb = netdev_alloc_skb(dev, RX_SIZE);
718 			if (skb) {
719 				phys = dma_map_single(&dev->dev, skb->data,
720 						      RX_SIZE,
721 						      DMA_FROM_DEVICE);
722 				if (dma_mapping_error(&dev->dev, phys)) {
723 					dev_kfree_skb(skb);
724 					skb = NULL;
725 				}
726 			}
727 #else
728 			skb = netdev_alloc_skb(dev, desc->pkt_len);
729 #endif
730 			if (!skb)
731 				dev->stats.rx_dropped++;
732 			break;
733 		case ERR_HDLC_ALIGN:
734 		case ERR_HDLC_ABORT:
735 			dev->stats.rx_frame_errors++;
736 			dev->stats.rx_errors++;
737 			break;
738 		case ERR_HDLC_FCS:
739 			dev->stats.rx_crc_errors++;
740 			dev->stats.rx_errors++;
741 			break;
742 		case ERR_HDLC_TOO_LONG:
743 			dev->stats.rx_length_errors++;
744 			dev->stats.rx_errors++;
745 			break;
746 		default:	/* FIXME - remove printk */
747 			netdev_err(dev, "hss_hdlc_poll: status 0x%02X errors %u\n",
748 				   desc->status, desc->error_count);
749 			dev->stats.rx_errors++;
750 		}
751 
752 		if (!skb) {
753 			/* put the desc back on RX-ready queue */
754 			desc->buf_len = RX_SIZE;
755 			desc->pkt_len = desc->status = 0;
756 			queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
757 			continue;
758 		}
759 
760 		/* process received frame */
761 #ifdef __ARMEB__
762 		temp = skb;
763 		skb = port->rx_buff_tab[n];
764 		dma_unmap_single(&dev->dev, desc->data,
765 				 RX_SIZE, DMA_FROM_DEVICE);
766 #else
767 		dma_sync_single_for_cpu(&dev->dev, desc->data,
768 					RX_SIZE, DMA_FROM_DEVICE);
769 		memcpy_swab32((u32 *)skb->data, (u32 *)port->rx_buff_tab[n],
770 			      ALIGN(desc->pkt_len, 4) / 4);
771 #endif
772 		skb_put(skb, desc->pkt_len);
773 
774 		debug_pkt(dev, "hss_hdlc_poll", skb->data, skb->len);
775 
776 		skb->protocol = hdlc_type_trans(skb, dev);
777 		dev->stats.rx_packets++;
778 		dev->stats.rx_bytes += skb->len;
779 		netif_receive_skb(skb);
780 
781 		/* put the new buffer on RX-free queue */
782 #ifdef __ARMEB__
783 		port->rx_buff_tab[n] = temp;
784 		desc->data = phys;
785 #endif
786 		desc->buf_len = RX_SIZE;
787 		desc->pkt_len = 0;
788 		queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
789 		received++;
790 	}
791 #if DEBUG_RX
792 	printk(KERN_DEBUG "hss_hdlc_poll: end, not all work done\n");
793 #endif
794 	return received;	/* not all work done */
795 }
796 
797 static void hss_hdlc_txdone_irq(void *pdev)
798 {
799 	struct net_device *dev = pdev;
800 	struct port *port = dev_to_port(dev);
801 	int n_desc;
802 
803 #if DEBUG_TX
804 	printk(KERN_DEBUG DRV_NAME ": hss_hdlc_txdone_irq\n");
805 #endif
806 	while ((n_desc = queue_get_desc(port->txdoneq,
807 					port, 1)) >= 0) {
808 		struct desc *desc;
809 		int start;
810 
811 		desc = tx_desc_ptr(port, n_desc);
812 
813 		dev->stats.tx_packets++;
814 		dev->stats.tx_bytes += desc->pkt_len;
815 
816 		dma_unmap_tx(port, desc);
817 #if DEBUG_TX
818 		printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq free %p\n",
819 		       dev->name, port->tx_buff_tab[n_desc]);
820 #endif
821 		free_buffer_irq(port->tx_buff_tab[n_desc]);
822 		port->tx_buff_tab[n_desc] = NULL;
823 
824 		start = qmgr_stat_below_low_watermark(port->txreadyq);
825 		queue_put_desc(port->txreadyq,
826 			       tx_desc_phys(port, n_desc), desc);
827 		if (start) { /* TX-ready queue was empty */
828 #if DEBUG_TX
829 			printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq xmit"
830 			       " ready\n", dev->name);
831 #endif
832 			netif_wake_queue(dev);
833 		}
834 	}
835 }
836 
837 static int hss_hdlc_xmit(struct sk_buff *skb, struct net_device *dev)
838 {
839 	struct port *port = dev_to_port(dev);
840 	unsigned int txreadyq = port->txreadyq;
841 	int len, offset, bytes, n;
842 	void *mem;
843 	u32 phys;
844 	struct desc *desc;
845 
846 #if DEBUG_TX
847 	printk(KERN_DEBUG "%s: hss_hdlc_xmit\n", dev->name);
848 #endif
849 
850 	if (unlikely(skb->len > HDLC_MAX_MRU)) {
851 		dev_kfree_skb(skb);
852 		dev->stats.tx_errors++;
853 		return NETDEV_TX_OK;
854 	}
855 
856 	debug_pkt(dev, "hss_hdlc_xmit", skb->data, skb->len);
857 
858 	len = skb->len;
859 #ifdef __ARMEB__
860 	offset = 0; /* no need to keep alignment */
861 	bytes = len;
862 	mem = skb->data;
863 #else
864 	offset = (int)skb->data & 3; /* keep 32-bit alignment */
865 	bytes = ALIGN(offset + len, 4);
866 	mem = kmalloc(bytes, GFP_ATOMIC);
867 	if (!mem) {
868 		dev_kfree_skb(skb);
869 		dev->stats.tx_dropped++;
870 		return NETDEV_TX_OK;
871 	}
872 	memcpy_swab32(mem, (u32 *)((uintptr_t)skb->data & ~3), bytes / 4);
873 	dev_kfree_skb(skb);
874 #endif
875 
876 	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
877 	if (dma_mapping_error(&dev->dev, phys)) {
878 #ifdef __ARMEB__
879 		dev_kfree_skb(skb);
880 #else
881 		kfree(mem);
882 #endif
883 		dev->stats.tx_dropped++;
884 		return NETDEV_TX_OK;
885 	}
886 
887 	n = queue_get_desc(txreadyq, port, 1);
888 	BUG_ON(n < 0);
889 	desc = tx_desc_ptr(port, n);
890 
891 #ifdef __ARMEB__
892 	port->tx_buff_tab[n] = skb;
893 #else
894 	port->tx_buff_tab[n] = mem;
895 #endif
896 	desc->data = phys + offset;
897 	desc->buf_len = desc->pkt_len = len;
898 
899 	wmb();
900 	queue_put_desc(port->txq, tx_desc_phys(port, n), desc);
901 
902 	if (qmgr_stat_below_low_watermark(txreadyq)) { /* empty */
903 #if DEBUG_TX
904 		printk(KERN_DEBUG "%s: hss_hdlc_xmit queue full\n", dev->name);
905 #endif
906 		netif_stop_queue(dev);
907 		/* we could miss TX ready interrupt */
908 		if (!qmgr_stat_below_low_watermark(txreadyq)) {
909 #if DEBUG_TX
910 			printk(KERN_DEBUG "%s: hss_hdlc_xmit ready again\n",
911 			       dev->name);
912 #endif
913 			netif_wake_queue(dev);
914 		}
915 	}
916 
917 #if DEBUG_TX
918 	printk(KERN_DEBUG "%s: hss_hdlc_xmit end\n", dev->name);
919 #endif
920 	return NETDEV_TX_OK;
921 }
922 
923 static int request_hdlc_queues(struct port *port)
924 {
925 	int err;
926 
927 	err = qmgr_request_queue(port->rxfreeq, RX_DESCS, 0, 0,
928 				 "%s:RX-free", port->netdev->name);
929 	if (err)
930 		return err;
931 
932 	err = qmgr_request_queue(port->rxq, RX_DESCS, 0, 0,
933 				 "%s:RX", port->netdev->name);
934 	if (err)
935 		goto rel_rxfree;
936 
937 	err = qmgr_request_queue(port->txq, TX_DESCS, 0, 0,
938 				 "%s:TX", port->netdev->name);
939 	if (err)
940 		goto rel_rx;
941 
942 	err = qmgr_request_queue(port->txreadyq, TX_DESCS, 0, 0,
943 				 "%s:TX-ready", port->netdev->name);
944 	if (err)
945 		goto rel_tx;
946 
947 	err = qmgr_request_queue(port->txdoneq, TX_DESCS, 0, 0,
948 				 "%s:TX-done", port->netdev->name);
949 	if (err)
950 		goto rel_txready;
951 	return 0;
952 
953 rel_txready:
954 	qmgr_release_queue(port->txreadyq);
955 rel_tx:
956 	qmgr_release_queue(port->txq);
957 rel_rx:
958 	qmgr_release_queue(port->rxq);
959 rel_rxfree:
960 	qmgr_release_queue(port->rxfreeq);
961 	printk(KERN_DEBUG "%s: unable to request hardware queues\n",
962 	       port->netdev->name);
963 	return err;
964 }
965 
966 static void release_hdlc_queues(struct port *port)
967 {
968 	qmgr_release_queue(port->rxfreeq);
969 	qmgr_release_queue(port->rxq);
970 	qmgr_release_queue(port->txdoneq);
971 	qmgr_release_queue(port->txq);
972 	qmgr_release_queue(port->txreadyq);
973 }
974 
975 static int init_hdlc_queues(struct port *port)
976 {
977 	int i;
978 
979 	if (!ports_open) {
980 		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
981 					   POOL_ALLOC_SIZE, 32, 0);
982 		if (!dma_pool)
983 			return -ENOMEM;
984 	}
985 
986 	port->desc_tab = dma_pool_zalloc(dma_pool, GFP_KERNEL,
987 					&port->desc_tab_phys);
988 	if (!port->desc_tab)
989 		return -ENOMEM;
990 	memset(port->rx_buff_tab, 0, sizeof(port->rx_buff_tab)); /* tables */
991 	memset(port->tx_buff_tab, 0, sizeof(port->tx_buff_tab));
992 
993 	/* Setup RX buffers */
994 	for (i = 0; i < RX_DESCS; i++) {
995 		struct desc *desc = rx_desc_ptr(port, i);
996 		buffer_t *buff;
997 		void *data;
998 #ifdef __ARMEB__
999 		buff = netdev_alloc_skb(port->netdev, RX_SIZE);
1000 		if (!buff)
1001 			return -ENOMEM;
1002 		data = buff->data;
1003 #else
1004 		buff = kmalloc(RX_SIZE, GFP_KERNEL);
1005 		if (!buff)
1006 			return -ENOMEM;
1007 		data = buff;
1008 #endif
1009 		desc->buf_len = RX_SIZE;
1010 		desc->data = dma_map_single(&port->netdev->dev, data,
1011 					    RX_SIZE, DMA_FROM_DEVICE);
1012 		if (dma_mapping_error(&port->netdev->dev, desc->data)) {
1013 			free_buffer(buff);
1014 			return -EIO;
1015 		}
1016 		port->rx_buff_tab[i] = buff;
1017 	}
1018 
1019 	return 0;
1020 }
1021 
1022 static void destroy_hdlc_queues(struct port *port)
1023 {
1024 	int i;
1025 
1026 	if (port->desc_tab) {
1027 		for (i = 0; i < RX_DESCS; i++) {
1028 			struct desc *desc = rx_desc_ptr(port, i);
1029 			buffer_t *buff = port->rx_buff_tab[i];
1030 
1031 			if (buff) {
1032 				dma_unmap_single(&port->netdev->dev,
1033 						 desc->data, RX_SIZE,
1034 						 DMA_FROM_DEVICE);
1035 				free_buffer(buff);
1036 			}
1037 		}
1038 		for (i = 0; i < TX_DESCS; i++) {
1039 			struct desc *desc = tx_desc_ptr(port, i);
1040 			buffer_t *buff = port->tx_buff_tab[i];
1041 
1042 			if (buff) {
1043 				dma_unmap_tx(port, desc);
1044 				free_buffer(buff);
1045 			}
1046 		}
1047 		dma_pool_free(dma_pool, port->desc_tab, port->desc_tab_phys);
1048 		port->desc_tab = NULL;
1049 	}
1050 
1051 	if (!ports_open && dma_pool) {
1052 		dma_pool_destroy(dma_pool);
1053 		dma_pool = NULL;
1054 	}
1055 }
1056 
1057 static irqreturn_t hss_hdlc_dcd_irq(int irq, void *data)
1058 {
1059 	struct net_device *dev = data;
1060 	struct port *port = dev_to_port(dev);
1061 	int val;
1062 
1063 	val = gpiod_get_value(port->dcd);
1064 	hss_hdlc_set_carrier(dev, val);
1065 
1066 	return IRQ_HANDLED;
1067 }
1068 
1069 static int hss_hdlc_open(struct net_device *dev)
1070 {
1071 	struct port *port = dev_to_port(dev);
1072 	unsigned long flags;
1073 	int i, err = 0;
1074 	int val;
1075 
1076 	err = hdlc_open(dev);
1077 	if (err)
1078 		return err;
1079 
1080 	err = hss_load_firmware(port);
1081 	if (err)
1082 		goto err_hdlc_close;
1083 
1084 	err = request_hdlc_queues(port);
1085 	if (err)
1086 		goto err_hdlc_close;
1087 
1088 	err = init_hdlc_queues(port);
1089 	if (err)
1090 		goto err_destroy_queues;
1091 
1092 	spin_lock_irqsave(&npe_lock, flags);
1093 
1094 	/* Set the carrier, the GPIO is flagged active low so this will return
1095 	 * 1 if DCD is asserted.
1096 	 */
1097 	val = gpiod_get_value(port->dcd);
1098 	hss_hdlc_set_carrier(dev, val);
1099 
1100 	/* Set up an IRQ for DCD */
1101 	err = request_irq(gpiod_to_irq(port->dcd), hss_hdlc_dcd_irq, 0, "IXP4xx HSS", dev);
1102 	if (err) {
1103 		dev_err(&dev->dev, "ixp4xx_hss: failed to request DCD IRQ (%i)\n", err);
1104 		goto err_unlock;
1105 	}
1106 
1107 	/* GPIOs are flagged active low so this asserts DTR and RTS */
1108 	gpiod_set_value(port->dtr, 1);
1109 	gpiod_set_value(port->rts, 1);
1110 
1111 	spin_unlock_irqrestore(&npe_lock, flags);
1112 
1113 	/* Populate queues with buffers, no failure after this point */
1114 	for (i = 0; i < TX_DESCS; i++)
1115 		queue_put_desc(port->txreadyq,
1116 			       tx_desc_phys(port, i), tx_desc_ptr(port, i));
1117 
1118 	for (i = 0; i < RX_DESCS; i++)
1119 		queue_put_desc(port->rxfreeq,
1120 			       rx_desc_phys(port, i), rx_desc_ptr(port, i));
1121 
1122 	napi_enable(&port->napi);
1123 	netif_start_queue(dev);
1124 
1125 	qmgr_set_irq(port->rxq, QUEUE_IRQ_SRC_NOT_EMPTY,
1126 		     hss_hdlc_rx_irq, dev);
1127 
1128 	qmgr_set_irq(port->txdoneq, QUEUE_IRQ_SRC_NOT_EMPTY,
1129 		     hss_hdlc_txdone_irq, dev);
1130 	qmgr_enable_irq(port->txdoneq);
1131 
1132 	ports_open++;
1133 
1134 	hss_set_hdlc_cfg(port);
1135 	hss_config(port);
1136 
1137 	hss_start_hdlc(port);
1138 
1139 	/* we may already have RX data, enables IRQ */
1140 	napi_schedule(&port->napi);
1141 	return 0;
1142 
1143 err_unlock:
1144 	spin_unlock_irqrestore(&npe_lock, flags);
1145 err_destroy_queues:
1146 	destroy_hdlc_queues(port);
1147 	release_hdlc_queues(port);
1148 err_hdlc_close:
1149 	hdlc_close(dev);
1150 	return err;
1151 }
1152 
1153 static int hss_hdlc_close(struct net_device *dev)
1154 {
1155 	struct port *port = dev_to_port(dev);
1156 	unsigned long flags;
1157 	int i, buffs = RX_DESCS; /* allocated RX buffers */
1158 
1159 	spin_lock_irqsave(&npe_lock, flags);
1160 	ports_open--;
1161 	qmgr_disable_irq(port->rxq);
1162 	netif_stop_queue(dev);
1163 	napi_disable(&port->napi);
1164 
1165 	hss_stop_hdlc(port);
1166 
1167 	while (queue_get_desc(port->rxfreeq, port, 0) >= 0)
1168 		buffs--;
1169 	while (queue_get_desc(port->rxq, port, 0) >= 0)
1170 		buffs--;
1171 
1172 	if (buffs)
1173 		netdev_crit(dev, "unable to drain RX queue, %i buffer(s) left in NPE\n",
1174 			    buffs);
1175 
1176 	buffs = TX_DESCS;
1177 	while (queue_get_desc(port->txq, port, 1) >= 0)
1178 		buffs--; /* cancel TX */
1179 
1180 	i = 0;
1181 	do {
1182 		while (queue_get_desc(port->txreadyq, port, 1) >= 0)
1183 			buffs--;
1184 		if (!buffs)
1185 			break;
1186 	} while (++i < MAX_CLOSE_WAIT);
1187 
1188 	if (buffs)
1189 		netdev_crit(dev, "unable to drain TX queue, %i buffer(s) left in NPE\n",
1190 			    buffs);
1191 #if DEBUG_CLOSE
1192 	if (!buffs)
1193 		printk(KERN_DEBUG "Draining TX queues took %i cycles\n", i);
1194 #endif
1195 	qmgr_disable_irq(port->txdoneq);
1196 
1197 	free_irq(gpiod_to_irq(port->dcd), dev);
1198 	/* GPIOs are flagged active low so this de-asserts DTR and RTS */
1199 	gpiod_set_value(port->dtr, 0);
1200 	gpiod_set_value(port->rts, 0);
1201 	spin_unlock_irqrestore(&npe_lock, flags);
1202 
1203 	destroy_hdlc_queues(port);
1204 	release_hdlc_queues(port);
1205 	hdlc_close(dev);
1206 	return 0;
1207 }
1208 
1209 static int hss_hdlc_attach(struct net_device *dev, unsigned short encoding,
1210 			   unsigned short parity)
1211 {
1212 	struct port *port = dev_to_port(dev);
1213 
1214 	if (encoding != ENCODING_NRZ)
1215 		return -EINVAL;
1216 
1217 	switch (parity) {
1218 	case PARITY_CRC16_PR1_CCITT:
1219 		port->hdlc_cfg = 0;
1220 		return 0;
1221 
1222 	case PARITY_CRC32_PR1_CCITT:
1223 		port->hdlc_cfg = PKT_HDLC_CRC_32;
1224 		return 0;
1225 
1226 	default:
1227 		return -EINVAL;
1228 	}
1229 }
1230 
1231 static u32 check_clock(u32 timer_freq, u32 rate, u32 a, u32 b, u32 c,
1232 		       u32 *best, u32 *best_diff, u32 *reg)
1233 {
1234 	/* a is 10-bit, b is 10-bit, c is 12-bit */
1235 	u64 new_rate;
1236 	u32 new_diff;
1237 
1238 	new_rate = timer_freq * (u64)(c + 1);
1239 	do_div(new_rate, a * (c + 1) + b + 1);
1240 	new_diff = abs((u32)new_rate - rate);
1241 
1242 	if (new_diff < *best_diff) {
1243 		*best = new_rate;
1244 		*best_diff = new_diff;
1245 		*reg = (a << 22) | (b << 12) | c;
1246 	}
1247 	return new_diff;
1248 }
1249 
1250 static void find_best_clock(u32 timer_freq, u32 rate, u32 *best, u32 *reg)
1251 {
1252 	u32 a, b, diff = 0xFFFFFFFF;
1253 
1254 	a = timer_freq / rate;
1255 
1256 	if (a > 0x3FF) { /* 10-bit value - we can go as slow as ca. 65 kb/s */
1257 		check_clock(timer_freq, rate, 0x3FF, 1, 1, best, &diff, reg);
1258 		return;
1259 	}
1260 	if (a == 0) { /* > 66.666 MHz */
1261 		a = 1; /* minimum divider is 1 (a = 0, b = 1, c = 1) */
1262 		rate = timer_freq;
1263 	}
1264 
1265 	if (rate * a == timer_freq) { /* don't divide by 0 later */
1266 		check_clock(timer_freq, rate, a - 1, 1, 1, best, &diff, reg);
1267 		return;
1268 	}
1269 
1270 	for (b = 0; b < 0x400; b++) {
1271 		u64 c = (b + 1) * (u64)rate;
1272 
1273 		do_div(c, timer_freq - rate * a);
1274 		c--;
1275 		if (c >= 0xFFF) { /* 12-bit - no need to check more 'b's */
1276 			if (b == 0 && /* also try a bit higher rate */
1277 			    !check_clock(timer_freq, rate, a - 1, 1, 1, best,
1278 					 &diff, reg))
1279 				return;
1280 			check_clock(timer_freq, rate, a, b, 0xFFF, best,
1281 				    &diff, reg);
1282 			return;
1283 		}
1284 		if (!check_clock(timer_freq, rate, a, b, c, best, &diff, reg))
1285 			return;
1286 		if (!check_clock(timer_freq, rate, a, b, c + 1, best, &diff,
1287 				 reg))
1288 			return;
1289 	}
1290 }
1291 
1292 static int hss_hdlc_set_clock(struct port *port, unsigned int clock_type)
1293 {
1294 	switch (clock_type) {
1295 	case CLOCK_DEFAULT:
1296 	case CLOCK_EXT:
1297 		gpiod_set_value(port->clk_internal, 0);
1298 		return CLOCK_EXT;
1299 	case CLOCK_INT:
1300 		gpiod_set_value(port->clk_internal, 1);
1301 		return CLOCK_INT;
1302 	default:
1303 		return -EINVAL;
1304 	}
1305 }
1306 
1307 static int hss_hdlc_ioctl(struct net_device *dev, struct if_settings *ifs)
1308 {
1309 	const size_t size = sizeof(sync_serial_settings);
1310 	sync_serial_settings new_line;
1311 	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
1312 	struct port *port = dev_to_port(dev);
1313 	unsigned long flags;
1314 	int clk;
1315 
1316 	switch (ifs->type) {
1317 	case IF_GET_IFACE:
1318 		ifs->type = IF_IFACE_V35;
1319 		if (ifs->size < size) {
1320 			ifs->size = size; /* data size wanted */
1321 			return -ENOBUFS;
1322 		}
1323 		memset(&new_line, 0, sizeof(new_line));
1324 		new_line.clock_type = port->clock_type;
1325 		new_line.clock_rate = port->clock_rate;
1326 		new_line.loopback = port->loopback;
1327 		if (copy_to_user(line, &new_line, size))
1328 			return -EFAULT;
1329 		return 0;
1330 
1331 	case IF_IFACE_SYNC_SERIAL:
1332 	case IF_IFACE_V35:
1333 		if (!capable(CAP_NET_ADMIN))
1334 			return -EPERM;
1335 		if (copy_from_user(&new_line, line, size))
1336 			return -EFAULT;
1337 
1338 		clk = new_line.clock_type;
1339 		hss_hdlc_set_clock(port, clk);
1340 
1341 		if (clk != CLOCK_EXT && clk != CLOCK_INT)
1342 			return -EINVAL;	/* No such clock setting */
1343 
1344 		if (new_line.loopback != 0 && new_line.loopback != 1)
1345 			return -EINVAL;
1346 
1347 		port->clock_type = clk; /* Update settings */
1348 		if (clk == CLOCK_INT) {
1349 			find_best_clock(IXP4XX_TIMER_FREQ,
1350 					new_line.clock_rate,
1351 					&port->clock_rate, &port->clock_reg);
1352 		} else {
1353 			port->clock_rate = 0;
1354 			port->clock_reg = CLK42X_SPEED_2048KHZ;
1355 		}
1356 		port->loopback = new_line.loopback;
1357 
1358 		spin_lock_irqsave(&npe_lock, flags);
1359 
1360 		if (dev->flags & IFF_UP)
1361 			hss_config(port);
1362 
1363 		if (port->loopback || port->carrier)
1364 			netif_carrier_on(port->netdev);
1365 		else
1366 			netif_carrier_off(port->netdev);
1367 		spin_unlock_irqrestore(&npe_lock, flags);
1368 
1369 		return 0;
1370 
1371 	default:
1372 		return hdlc_ioctl(dev, ifs);
1373 	}
1374 }
1375 
1376 /*****************************************************************************
1377  * initialization
1378  ****************************************************************************/
1379 
1380 static const struct net_device_ops hss_hdlc_ops = {
1381 	.ndo_open       = hss_hdlc_open,
1382 	.ndo_stop       = hss_hdlc_close,
1383 	.ndo_start_xmit = hdlc_start_xmit,
1384 	.ndo_siocwandev = hss_hdlc_ioctl,
1385 };
1386 
1387 static int ixp4xx_hss_probe(struct platform_device *pdev)
1388 {
1389 	struct of_phandle_args queue_spec;
1390 	struct of_phandle_args npe_spec;
1391 	struct device *dev = &pdev->dev;
1392 	struct net_device *ndev;
1393 	struct device_node *np;
1394 	struct regmap *rmap;
1395 	struct port *port;
1396 	hdlc_device *hdlc;
1397 	int err;
1398 	u32 val;
1399 
1400 	/*
1401 	 * Go into the syscon and check if we have the HSS and HDLC
1402 	 * features available, else this will not work.
1403 	 */
1404 	rmap = syscon_regmap_lookup_by_compatible("syscon");
1405 	if (IS_ERR(rmap))
1406 		return dev_err_probe(dev, PTR_ERR(rmap),
1407 				     "failed to look up syscon\n");
1408 
1409 	val = cpu_ixp4xx_features(rmap);
1410 
1411 	if ((val & (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) !=
1412 	    (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) {
1413 		dev_err(dev, "HDLC and HSS feature unavailable in platform\n");
1414 		return -ENODEV;
1415 	}
1416 
1417 	np = dev->of_node;
1418 
1419 	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
1420 	if (!port)
1421 		return -ENOMEM;
1422 
1423 	err = of_parse_phandle_with_fixed_args(np, "intel,npe-handle", 1, 0,
1424 					       &npe_spec);
1425 	if (err)
1426 		return dev_err_probe(dev, err, "no NPE engine specified\n");
1427 	/* NPE ID 0x00, 0x10, 0x20... */
1428 	port->npe = npe_request(npe_spec.args[0] << 4);
1429 	if (!port->npe) {
1430 		dev_err(dev, "unable to obtain NPE instance\n");
1431 		return -ENODEV;
1432 	}
1433 
1434 	/* Get the TX ready queue as resource from queue manager */
1435 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-chl-txready", 1, 0,
1436 					       &queue_spec);
1437 	if (err)
1438 		return dev_err_probe(dev, err, "no txready queue phandle\n");
1439 	port->txreadyq = queue_spec.args[0];
1440 	/* Get the RX trig queue as resource from queue manager */
1441 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-chl-rxtrig", 1, 0,
1442 					       &queue_spec);
1443 	if (err)
1444 		return dev_err_probe(dev, err, "no rxtrig queue phandle\n");
1445 	port->rxtrigq = queue_spec.args[0];
1446 	/* Get the RX queue as resource from queue manager */
1447 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-rx", 1, 0,
1448 					       &queue_spec);
1449 	if (err)
1450 		return dev_err_probe(dev, err, "no RX queue phandle\n");
1451 	port->rxq = queue_spec.args[0];
1452 	/* Get the TX queue as resource from queue manager */
1453 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-tx", 1, 0,
1454 					       &queue_spec);
1455 	if (err)
1456 		return dev_err_probe(dev, err, "no RX queue phandle\n");
1457 	port->txq = queue_spec.args[0];
1458 	/* Get the RX free queue as resource from queue manager */
1459 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-rxfree", 1, 0,
1460 					       &queue_spec);
1461 	if (err)
1462 		return dev_err_probe(dev, err, "no RX free queue phandle\n");
1463 	port->rxfreeq = queue_spec.args[0];
1464 	/* Get the TX done queue as resource from queue manager */
1465 	err = of_parse_phandle_with_fixed_args(np, "intek,queue-pkt-txdone", 1, 0,
1466 					       &queue_spec);
1467 	if (err)
1468 		return dev_err_probe(dev, err, "no TX done queue phandle\n");
1469 	port->txdoneq = queue_spec.args[0];
1470 
1471 	/* Obtain all the line control GPIOs */
1472 	port->cts = devm_gpiod_get(dev, "cts", GPIOD_OUT_LOW);
1473 	if (IS_ERR(port->cts))
1474 		return dev_err_probe(dev, PTR_ERR(port->cts), "unable to get CTS GPIO\n");
1475 	port->rts = devm_gpiod_get(dev, "rts", GPIOD_OUT_LOW);
1476 	if (IS_ERR(port->rts))
1477 		return dev_err_probe(dev, PTR_ERR(port->rts), "unable to get RTS GPIO\n");
1478 	port->dcd = devm_gpiod_get(dev, "dcd", GPIOD_IN);
1479 	if (IS_ERR(port->dcd))
1480 		return dev_err_probe(dev, PTR_ERR(port->dcd), "unable to get DCD GPIO\n");
1481 	port->dtr = devm_gpiod_get(dev, "dtr", GPIOD_OUT_LOW);
1482 	if (IS_ERR(port->dtr))
1483 		return dev_err_probe(dev, PTR_ERR(port->dtr), "unable to get DTR GPIO\n");
1484 	port->clk_internal = devm_gpiod_get(dev, "clk-internal", GPIOD_OUT_LOW);
1485 	if (IS_ERR(port->clk_internal))
1486 		return dev_err_probe(dev, PTR_ERR(port->clk_internal),
1487 				     "unable to get CLK internal GPIO\n");
1488 
1489 	ndev = alloc_hdlcdev(port);
1490 	port->netdev = alloc_hdlcdev(port);
1491 	if (!port->netdev) {
1492 		err = -ENOMEM;
1493 		goto err_plat;
1494 	}
1495 
1496 	SET_NETDEV_DEV(ndev, &pdev->dev);
1497 	hdlc = dev_to_hdlc(ndev);
1498 	hdlc->attach = hss_hdlc_attach;
1499 	hdlc->xmit = hss_hdlc_xmit;
1500 	ndev->netdev_ops = &hss_hdlc_ops;
1501 	ndev->tx_queue_len = 100;
1502 	port->clock_type = CLOCK_EXT;
1503 	port->clock_rate = 0;
1504 	port->clock_reg = CLK42X_SPEED_2048KHZ;
1505 	port->id = pdev->id;
1506 	port->dev = &pdev->dev;
1507 	netif_napi_add(ndev, &port->napi, hss_hdlc_poll, NAPI_WEIGHT);
1508 
1509 	err = register_hdlc_device(ndev);
1510 	if (err)
1511 		goto err_free_netdev;
1512 
1513 	platform_set_drvdata(pdev, port);
1514 
1515 	netdev_info(ndev, "initialized\n");
1516 	return 0;
1517 
1518 err_free_netdev:
1519 	free_netdev(ndev);
1520 err_plat:
1521 	npe_release(port->npe);
1522 	return err;
1523 }
1524 
1525 static int ixp4xx_hss_remove(struct platform_device *pdev)
1526 {
1527 	struct port *port = platform_get_drvdata(pdev);
1528 
1529 	unregister_hdlc_device(port->netdev);
1530 	free_netdev(port->netdev);
1531 	npe_release(port->npe);
1532 	return 0;
1533 }
1534 
1535 static struct platform_driver ixp4xx_hss_driver = {
1536 	.driver.name	= DRV_NAME,
1537 	.probe		= ixp4xx_hss_probe,
1538 	.remove		= ixp4xx_hss_remove,
1539 };
1540 module_platform_driver(ixp4xx_hss_driver);
1541 
1542 MODULE_AUTHOR("Krzysztof Halasa");
1543 MODULE_DESCRIPTION("Intel IXP4xx HSS driver");
1544 MODULE_LICENSE("GPL v2");
1545 MODULE_ALIAS("platform:ixp4xx_hss");
1546