xref: /openbmc/linux/drivers/net/wan/ixp4xx_hss.c (revision 4419617e)
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/platform_device.h>
20 #include <linux/poll.h>
21 #include <linux/slab.h>
22 #include <linux/soc/ixp4xx/npe.h>
23 #include <linux/soc/ixp4xx/qmgr.h>
24 
25 #define DEBUG_DESC		0
26 #define DEBUG_RX		0
27 #define DEBUG_TX		0
28 #define DEBUG_PKT_BYTES		0
29 #define DEBUG_CLOSE		0
30 
31 #define DRV_NAME		"ixp4xx_hss"
32 
33 #define PKT_EXTRA_FLAGS		0 /* orig 1 */
34 #define PKT_NUM_PIPES		1 /* 1, 2 or 4 */
35 #define PKT_PIPE_FIFO_SIZEW	4 /* total 4 dwords per HSS */
36 
37 #define RX_DESCS		16 /* also length of all RX queues */
38 #define TX_DESCS		16 /* also length of all TX queues */
39 
40 #define POOL_ALLOC_SIZE		(sizeof(struct desc) * (RX_DESCS + TX_DESCS))
41 #define RX_SIZE			(HDLC_MAX_MRU + 4) /* NPE needs more space */
42 #define MAX_CLOSE_WAIT		1000 /* microseconds */
43 #define HSS_COUNT		2
44 #define FRAME_SIZE		256 /* doesn't matter at this point */
45 #define FRAME_OFFSET		0
46 #define MAX_CHANNELS		(FRAME_SIZE / 8)
47 
48 #define NAPI_WEIGHT		16
49 
50 /* Queue IDs */
51 #define HSS0_CHL_RXTRIG_QUEUE	12	/* orig size = 32 dwords */
52 #define HSS0_PKT_RX_QUEUE	13	/* orig size = 32 dwords */
53 #define HSS0_PKT_TX0_QUEUE	14	/* orig size = 16 dwords */
54 #define HSS0_PKT_TX1_QUEUE	15
55 #define HSS0_PKT_TX2_QUEUE	16
56 #define HSS0_PKT_TX3_QUEUE	17
57 #define HSS0_PKT_RXFREE0_QUEUE	18	/* orig size = 16 dwords */
58 #define HSS0_PKT_RXFREE1_QUEUE	19
59 #define HSS0_PKT_RXFREE2_QUEUE	20
60 #define HSS0_PKT_RXFREE3_QUEUE	21
61 #define HSS0_PKT_TXDONE_QUEUE	22	/* orig size = 64 dwords */
62 
63 #define HSS1_CHL_RXTRIG_QUEUE	10
64 #define HSS1_PKT_RX_QUEUE	0
65 #define HSS1_PKT_TX0_QUEUE	5
66 #define HSS1_PKT_TX1_QUEUE	6
67 #define HSS1_PKT_TX2_QUEUE	7
68 #define HSS1_PKT_TX3_QUEUE	8
69 #define HSS1_PKT_RXFREE0_QUEUE	1
70 #define HSS1_PKT_RXFREE1_QUEUE	2
71 #define HSS1_PKT_RXFREE2_QUEUE	3
72 #define HSS1_PKT_RXFREE3_QUEUE	4
73 #define HSS1_PKT_TXDONE_QUEUE	9
74 
75 #define NPE_PKT_MODE_HDLC		0
76 #define NPE_PKT_MODE_RAW		1
77 #define NPE_PKT_MODE_56KMODE		2
78 #define NPE_PKT_MODE_56KENDIAN_MSB	4
79 
80 /* PKT_PIPE_HDLC_CFG_WRITE flags */
81 #define PKT_HDLC_IDLE_ONES		0x1 /* default = flags */
82 #define PKT_HDLC_CRC_32			0x2 /* default = CRC-16 */
83 #define PKT_HDLC_MSB_ENDIAN		0x4 /* default = LE */
84 
85 
86 /* hss_config, PCRs */
87 /* Frame sync sampling, default = active low */
88 #define PCR_FRM_SYNC_ACTIVE_HIGH	0x40000000
89 #define PCR_FRM_SYNC_FALLINGEDGE	0x80000000
90 #define PCR_FRM_SYNC_RISINGEDGE		0xC0000000
91 
92 /* Frame sync pin: input (default) or output generated off a given clk edge */
93 #define PCR_FRM_SYNC_OUTPUT_FALLING	0x20000000
94 #define PCR_FRM_SYNC_OUTPUT_RISING	0x30000000
95 
96 /* Frame and data clock sampling on edge, default = falling */
97 #define PCR_FCLK_EDGE_RISING		0x08000000
98 #define PCR_DCLK_EDGE_RISING		0x04000000
99 
100 /* Clock direction, default = input */
101 #define PCR_SYNC_CLK_DIR_OUTPUT		0x02000000
102 
103 /* Generate/Receive frame pulses, default = enabled */
104 #define PCR_FRM_PULSE_DISABLED		0x01000000
105 
106  /* Data rate is full (default) or half the configured clk speed */
107 #define PCR_HALF_CLK_RATE		0x00200000
108 
109 /* Invert data between NPE and HSS FIFOs? (default = no) */
110 #define PCR_DATA_POLARITY_INVERT	0x00100000
111 
112 /* TX/RX endianness, default = LSB */
113 #define PCR_MSB_ENDIAN			0x00080000
114 
115 /* Normal (default) / open drain mode (TX only) */
116 #define PCR_TX_PINS_OPEN_DRAIN		0x00040000
117 
118 /* No framing bit transmitted and expected on RX? (default = framing bit) */
119 #define PCR_SOF_NO_FBIT			0x00020000
120 
121 /* Drive data pins? */
122 #define PCR_TX_DATA_ENABLE		0x00010000
123 
124 /* Voice 56k type: drive the data pins low (default), high, high Z */
125 #define PCR_TX_V56K_HIGH		0x00002000
126 #define PCR_TX_V56K_HIGH_IMP		0x00004000
127 
128 /* Unassigned type: drive the data pins low (default), high, high Z */
129 #define PCR_TX_UNASS_HIGH		0x00000800
130 #define PCR_TX_UNASS_HIGH_IMP		0x00001000
131 
132 /* T1 @ 1.544MHz only: Fbit dictated in FIFO (default) or high Z */
133 #define PCR_TX_FB_HIGH_IMP		0x00000400
134 
135 /* 56k data endiannes - which bit unused: high (default) or low */
136 #define PCR_TX_56KE_BIT_0_UNUSED	0x00000200
137 
138 /* 56k data transmission type: 32/8 bit data (default) or 56K data */
139 #define PCR_TX_56KS_56K_DATA		0x00000100
140 
141 /* hss_config, cCR */
142 /* Number of packetized clients, default = 1 */
143 #define CCR_NPE_HFIFO_2_HDLC		0x04000000
144 #define CCR_NPE_HFIFO_3_OR_4HDLC	0x08000000
145 
146 /* default = no loopback */
147 #define CCR_LOOPBACK			0x02000000
148 
149 /* HSS number, default = 0 (first) */
150 #define CCR_SECOND_HSS			0x01000000
151 
152 
153 /* hss_config, clkCR: main:10, num:10, denom:12 */
154 #define CLK42X_SPEED_EXP	((0x3FF << 22) | (  2 << 12) |   15) /*65 KHz*/
155 
156 #define CLK42X_SPEED_512KHZ	((  130 << 22) | (  2 << 12) |   15)
157 #define CLK42X_SPEED_1536KHZ	((   43 << 22) | ( 18 << 12) |   47)
158 #define CLK42X_SPEED_1544KHZ	((   43 << 22) | ( 33 << 12) |  192)
159 #define CLK42X_SPEED_2048KHZ	((   32 << 22) | ( 34 << 12) |   63)
160 #define CLK42X_SPEED_4096KHZ	((   16 << 22) | ( 34 << 12) |  127)
161 #define CLK42X_SPEED_8192KHZ	((    8 << 22) | ( 34 << 12) |  255)
162 
163 #define CLK46X_SPEED_512KHZ	((  130 << 22) | ( 24 << 12) |  127)
164 #define CLK46X_SPEED_1536KHZ	((   43 << 22) | (152 << 12) |  383)
165 #define CLK46X_SPEED_1544KHZ	((   43 << 22) | ( 66 << 12) |  385)
166 #define CLK46X_SPEED_2048KHZ	((   32 << 22) | (280 << 12) |  511)
167 #define CLK46X_SPEED_4096KHZ	((   16 << 22) | (280 << 12) | 1023)
168 #define CLK46X_SPEED_8192KHZ	((    8 << 22) | (280 << 12) | 2047)
169 
170 /*
171  * HSS_CONFIG_CLOCK_CR register consists of 3 parts:
172  *     A (10 bits), B (10 bits) and C (12 bits).
173  * IXP42x HSS clock generator operation (verified with an oscilloscope):
174  * Each clock bit takes 7.5 ns (1 / 133.xx MHz).
175  * The clock sequence consists of (C - B) states of 0s and 1s, each state is
176  * A bits wide. It's followed by (B + 1) states of 0s and 1s, each state is
177  * (A + 1) bits wide.
178  *
179  * The resulting average clock frequency (assuming 33.333 MHz oscillator) is:
180  * freq = 66.666 MHz / (A + (B + 1) / (C + 1))
181  * minimum freq = 66.666 MHz / (A + 1)
182  * maximum freq = 66.666 MHz / A
183  *
184  * Example: A = 2, B = 2, C = 7, CLOCK_CR register = 2 << 22 | 2 << 12 | 7
185  * freq = 66.666 MHz / (2 + (2 + 1) / (7 + 1)) = 28.07 MHz (Mb/s).
186  * The clock sequence is: 1100110011 (5 doubles) 000111000 (3 triples).
187  * The sequence takes (C - B) * A + (B + 1) * (A + 1) = 5 * 2 + 3 * 3 bits
188  * = 19 bits (each 7.5 ns long) = 142.5 ns (then the sequence repeats).
189  * The sequence consists of 4 complete clock periods, thus the average
190  * frequency (= clock rate) is 4 / 142.5 ns = 28.07 MHz (Mb/s).
191  * (max specified clock rate for IXP42x HSS is 8.192 Mb/s).
192  */
193 
194 /* hss_config, LUT entries */
195 #define TDMMAP_UNASSIGNED	0
196 #define TDMMAP_HDLC		1	/* HDLC - packetized */
197 #define TDMMAP_VOICE56K		2	/* Voice56K - 7-bit channelized */
198 #define TDMMAP_VOICE64K		3	/* Voice64K - 8-bit channelized */
199 
200 /* offsets into HSS config */
201 #define HSS_CONFIG_TX_PCR	0x00 /* port configuration registers */
202 #define HSS_CONFIG_RX_PCR	0x04
203 #define HSS_CONFIG_CORE_CR	0x08 /* loopback control, HSS# */
204 #define HSS_CONFIG_CLOCK_CR	0x0C /* clock generator control */
205 #define HSS_CONFIG_TX_FCR	0x10 /* frame configuration registers */
206 #define HSS_CONFIG_RX_FCR	0x14
207 #define HSS_CONFIG_TX_LUT	0x18 /* channel look-up tables */
208 #define HSS_CONFIG_RX_LUT	0x38
209 
210 
211 /* NPE command codes */
212 /* writes the ConfigWord value to the location specified by offset */
213 #define PORT_CONFIG_WRITE		0x40
214 
215 /* triggers the NPE to load the contents of the configuration table */
216 #define PORT_CONFIG_LOAD		0x41
217 
218 /* triggers the NPE to return an HssErrorReadResponse message */
219 #define PORT_ERROR_READ			0x42
220 
221 /* triggers the NPE to reset internal status and enable the HssPacketized
222    operation for the flow specified by pPipe */
223 #define PKT_PIPE_FLOW_ENABLE		0x50
224 #define PKT_PIPE_FLOW_DISABLE		0x51
225 #define PKT_NUM_PIPES_WRITE		0x52
226 #define PKT_PIPE_FIFO_SIZEW_WRITE	0x53
227 #define PKT_PIPE_HDLC_CFG_WRITE		0x54
228 #define PKT_PIPE_IDLE_PATTERN_WRITE	0x55
229 #define PKT_PIPE_RX_SIZE_WRITE		0x56
230 #define PKT_PIPE_MODE_WRITE		0x57
231 
232 /* HDLC packet status values - desc->status */
233 #define ERR_SHUTDOWN		1 /* stop or shutdown occurrence */
234 #define ERR_HDLC_ALIGN		2 /* HDLC alignment error */
235 #define ERR_HDLC_FCS		3 /* HDLC Frame Check Sum error */
236 #define ERR_RXFREE_Q_EMPTY	4 /* RX-free queue became empty while receiving
237 				     this packet (if buf_len < pkt_len) */
238 #define ERR_HDLC_TOO_LONG	5 /* HDLC frame size too long */
239 #define ERR_HDLC_ABORT		6 /* abort sequence received */
240 #define ERR_DISCONNECTING	7 /* disconnect is in progress */
241 
242 
243 #ifdef __ARMEB__
244 typedef struct sk_buff buffer_t;
245 #define free_buffer dev_kfree_skb
246 #define free_buffer_irq dev_consume_skb_irq
247 #else
248 typedef void buffer_t;
249 #define free_buffer kfree
250 #define free_buffer_irq kfree
251 #endif
252 
253 struct port {
254 	struct device *dev;
255 	struct npe *npe;
256 	struct net_device *netdev;
257 	struct napi_struct napi;
258 	struct hss_plat_info *plat;
259 	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
260 	struct desc *desc_tab;	/* coherent */
261 	u32 desc_tab_phys;
262 	unsigned int id;
263 	unsigned int clock_type, clock_rate, loopback;
264 	unsigned int initialized, carrier;
265 	u8 hdlc_cfg;
266 	u32 clock_reg;
267 };
268 
269 /* NPE message structure */
270 struct msg {
271 #ifdef __ARMEB__
272 	u8 cmd, unused, hss_port, index;
273 	union {
274 		struct { u8 data8a, data8b, data8c, data8d; };
275 		struct { u16 data16a, data16b; };
276 		struct { u32 data32; };
277 	};
278 #else
279 	u8 index, hss_port, unused, cmd;
280 	union {
281 		struct { u8 data8d, data8c, data8b, data8a; };
282 		struct { u16 data16b, data16a; };
283 		struct { u32 data32; };
284 	};
285 #endif
286 };
287 
288 /* HDLC packet descriptor */
289 struct desc {
290 	u32 next;		/* pointer to next buffer, unused */
291 
292 #ifdef __ARMEB__
293 	u16 buf_len;		/* buffer length */
294 	u16 pkt_len;		/* packet length */
295 	u32 data;		/* pointer to data buffer in RAM */
296 	u8 status;
297 	u8 error_count;
298 	u16 __reserved;
299 #else
300 	u16 pkt_len;		/* packet length */
301 	u16 buf_len;		/* buffer length */
302 	u32 data;		/* pointer to data buffer in RAM */
303 	u16 __reserved;
304 	u8 error_count;
305 	u8 status;
306 #endif
307 	u32 __reserved1[4];
308 };
309 
310 
311 #define rx_desc_phys(port, n)	((port)->desc_tab_phys +		\
312 				 (n) * sizeof(struct desc))
313 #define rx_desc_ptr(port, n)	(&(port)->desc_tab[n])
314 
315 #define tx_desc_phys(port, n)	((port)->desc_tab_phys +		\
316 				 ((n) + RX_DESCS) * sizeof(struct desc))
317 #define tx_desc_ptr(port, n)	(&(port)->desc_tab[(n) + RX_DESCS])
318 
319 /*****************************************************************************
320  * global variables
321  ****************************************************************************/
322 
323 static int ports_open;
324 static struct dma_pool *dma_pool;
325 static spinlock_t npe_lock;
326 
327 static const struct {
328 	int tx, txdone, rx, rxfree;
329 }queue_ids[2] = {{HSS0_PKT_TX0_QUEUE, HSS0_PKT_TXDONE_QUEUE, HSS0_PKT_RX_QUEUE,
330 		  HSS0_PKT_RXFREE0_QUEUE},
331 		 {HSS1_PKT_TX0_QUEUE, HSS1_PKT_TXDONE_QUEUE, HSS1_PKT_RX_QUEUE,
332 		  HSS1_PKT_RXFREE0_QUEUE},
333 };
334 
335 /*****************************************************************************
336  * utility functions
337  ****************************************************************************/
338 
339 static inline struct port* dev_to_port(struct net_device *dev)
340 {
341 	return dev_to_hdlc(dev)->priv;
342 }
343 
344 #ifndef __ARMEB__
345 static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
346 {
347 	int i;
348 	for (i = 0; i < cnt; i++)
349 		dest[i] = swab32(src[i]);
350 }
351 #endif
352 
353 /*****************************************************************************
354  * HSS access
355  ****************************************************************************/
356 
357 static void hss_npe_send(struct port *port, struct msg *msg, const char* what)
358 {
359 	u32 *val = (u32*)msg;
360 	if (npe_send_message(port->npe, msg, what)) {
361 		pr_crit("HSS-%i: unable to send command [%08X:%08X] to %s\n",
362 			port->id, val[0], val[1], npe_name(port->npe));
363 		BUG();
364 	}
365 }
366 
367 static void hss_config_set_lut(struct port *port)
368 {
369 	struct msg msg;
370 	int ch;
371 
372 	memset(&msg, 0, sizeof(msg));
373 	msg.cmd = PORT_CONFIG_WRITE;
374 	msg.hss_port = port->id;
375 
376 	for (ch = 0; ch < MAX_CHANNELS; ch++) {
377 		msg.data32 >>= 2;
378 		msg.data32 |= TDMMAP_HDLC << 30;
379 
380 		if (ch % 16 == 15) {
381 			msg.index = HSS_CONFIG_TX_LUT + ((ch / 4) & ~3);
382 			hss_npe_send(port, &msg, "HSS_SET_TX_LUT");
383 
384 			msg.index += HSS_CONFIG_RX_LUT - HSS_CONFIG_TX_LUT;
385 			hss_npe_send(port, &msg, "HSS_SET_RX_LUT");
386 		}
387 	}
388 }
389 
390 static void hss_config(struct port *port)
391 {
392 	struct msg msg;
393 
394 	memset(&msg, 0, sizeof(msg));
395 	msg.cmd = PORT_CONFIG_WRITE;
396 	msg.hss_port = port->id;
397 	msg.index = HSS_CONFIG_TX_PCR;
398 	msg.data32 = PCR_FRM_PULSE_DISABLED | PCR_MSB_ENDIAN |
399 		PCR_TX_DATA_ENABLE | PCR_SOF_NO_FBIT;
400 	if (port->clock_type == CLOCK_INT)
401 		msg.data32 |= PCR_SYNC_CLK_DIR_OUTPUT;
402 	hss_npe_send(port, &msg, "HSS_SET_TX_PCR");
403 
404 	msg.index = HSS_CONFIG_RX_PCR;
405 	msg.data32 ^= PCR_TX_DATA_ENABLE | PCR_DCLK_EDGE_RISING;
406 	hss_npe_send(port, &msg, "HSS_SET_RX_PCR");
407 
408 	memset(&msg, 0, sizeof(msg));
409 	msg.cmd = PORT_CONFIG_WRITE;
410 	msg.hss_port = port->id;
411 	msg.index = HSS_CONFIG_CORE_CR;
412 	msg.data32 = (port->loopback ? CCR_LOOPBACK : 0) |
413 		(port->id ? CCR_SECOND_HSS : 0);
414 	hss_npe_send(port, &msg, "HSS_SET_CORE_CR");
415 
416 	memset(&msg, 0, sizeof(msg));
417 	msg.cmd = PORT_CONFIG_WRITE;
418 	msg.hss_port = port->id;
419 	msg.index = HSS_CONFIG_CLOCK_CR;
420 	msg.data32 = port->clock_reg;
421 	hss_npe_send(port, &msg, "HSS_SET_CLOCK_CR");
422 
423 	memset(&msg, 0, sizeof(msg));
424 	msg.cmd = PORT_CONFIG_WRITE;
425 	msg.hss_port = port->id;
426 	msg.index = HSS_CONFIG_TX_FCR;
427 	msg.data16a = FRAME_OFFSET;
428 	msg.data16b = FRAME_SIZE - 1;
429 	hss_npe_send(port, &msg, "HSS_SET_TX_FCR");
430 
431 	memset(&msg, 0, sizeof(msg));
432 	msg.cmd = PORT_CONFIG_WRITE;
433 	msg.hss_port = port->id;
434 	msg.index = HSS_CONFIG_RX_FCR;
435 	msg.data16a = FRAME_OFFSET;
436 	msg.data16b = FRAME_SIZE - 1;
437 	hss_npe_send(port, &msg, "HSS_SET_RX_FCR");
438 
439 	hss_config_set_lut(port);
440 
441 	memset(&msg, 0, sizeof(msg));
442 	msg.cmd = PORT_CONFIG_LOAD;
443 	msg.hss_port = port->id;
444 	hss_npe_send(port, &msg, "HSS_LOAD_CONFIG");
445 
446 	if (npe_recv_message(port->npe, &msg, "HSS_LOAD_CONFIG") ||
447 	    /* HSS_LOAD_CONFIG for port #1 returns port_id = #4 */
448 	    msg.cmd != PORT_CONFIG_LOAD || msg.data32) {
449 		pr_crit("HSS-%i: HSS_LOAD_CONFIG failed\n", port->id);
450 		BUG();
451 	}
452 
453 	/* HDLC may stop working without this - check FIXME */
454 	npe_recv_message(port->npe, &msg, "FLUSH_IT");
455 }
456 
457 static void hss_set_hdlc_cfg(struct port *port)
458 {
459 	struct msg msg;
460 
461 	memset(&msg, 0, sizeof(msg));
462 	msg.cmd = PKT_PIPE_HDLC_CFG_WRITE;
463 	msg.hss_port = port->id;
464 	msg.data8a = port->hdlc_cfg; /* rx_cfg */
465 	msg.data8b = port->hdlc_cfg | (PKT_EXTRA_FLAGS << 3); /* tx_cfg */
466 	hss_npe_send(port, &msg, "HSS_SET_HDLC_CFG");
467 }
468 
469 static u32 hss_get_status(struct port *port)
470 {
471 	struct msg msg;
472 
473 	memset(&msg, 0, sizeof(msg));
474 	msg.cmd = PORT_ERROR_READ;
475 	msg.hss_port = port->id;
476 	hss_npe_send(port, &msg, "PORT_ERROR_READ");
477 	if (npe_recv_message(port->npe, &msg, "PORT_ERROR_READ")) {
478 		pr_crit("HSS-%i: unable to read HSS status\n", port->id);
479 		BUG();
480 	}
481 
482 	return msg.data32;
483 }
484 
485 static void hss_start_hdlc(struct port *port)
486 {
487 	struct msg msg;
488 
489 	memset(&msg, 0, sizeof(msg));
490 	msg.cmd = PKT_PIPE_FLOW_ENABLE;
491 	msg.hss_port = port->id;
492 	msg.data32 = 0;
493 	hss_npe_send(port, &msg, "HSS_ENABLE_PKT_PIPE");
494 }
495 
496 static void hss_stop_hdlc(struct port *port)
497 {
498 	struct msg msg;
499 
500 	memset(&msg, 0, sizeof(msg));
501 	msg.cmd = PKT_PIPE_FLOW_DISABLE;
502 	msg.hss_port = port->id;
503 	hss_npe_send(port, &msg, "HSS_DISABLE_PKT_PIPE");
504 	hss_get_status(port); /* make sure it's halted */
505 }
506 
507 static int hss_load_firmware(struct port *port)
508 {
509 	struct msg msg;
510 	int err;
511 
512 	if (port->initialized)
513 		return 0;
514 
515 	if (!npe_running(port->npe) &&
516 	    (err = npe_load_firmware(port->npe, npe_name(port->npe),
517 				     port->dev)))
518 		return err;
519 
520 	/* HDLC mode configuration */
521 	memset(&msg, 0, sizeof(msg));
522 	msg.cmd = PKT_NUM_PIPES_WRITE;
523 	msg.hss_port = port->id;
524 	msg.data8a = PKT_NUM_PIPES;
525 	hss_npe_send(port, &msg, "HSS_SET_PKT_PIPES");
526 
527 	msg.cmd = PKT_PIPE_FIFO_SIZEW_WRITE;
528 	msg.data8a = PKT_PIPE_FIFO_SIZEW;
529 	hss_npe_send(port, &msg, "HSS_SET_PKT_FIFO");
530 
531 	msg.cmd = PKT_PIPE_MODE_WRITE;
532 	msg.data8a = NPE_PKT_MODE_HDLC;
533 	/* msg.data8b = inv_mask */
534 	/* msg.data8c = or_mask */
535 	hss_npe_send(port, &msg, "HSS_SET_PKT_MODE");
536 
537 	msg.cmd = PKT_PIPE_RX_SIZE_WRITE;
538 	msg.data16a = HDLC_MAX_MRU; /* including CRC */
539 	hss_npe_send(port, &msg, "HSS_SET_PKT_RX_SIZE");
540 
541 	msg.cmd = PKT_PIPE_IDLE_PATTERN_WRITE;
542 	msg.data32 = 0x7F7F7F7F; /* ??? FIXME */
543 	hss_npe_send(port, &msg, "HSS_SET_PKT_IDLE");
544 
545 	port->initialized = 1;
546 	return 0;
547 }
548 
549 /*****************************************************************************
550  * packetized (HDLC) operation
551  ****************************************************************************/
552 
553 static inline void debug_pkt(struct net_device *dev, const char *func,
554 			     u8 *data, int len)
555 {
556 #if DEBUG_PKT_BYTES
557 	int i;
558 
559 	printk(KERN_DEBUG "%s: %s(%i)", dev->name, func, len);
560 	for (i = 0; i < len; i++) {
561 		if (i >= DEBUG_PKT_BYTES)
562 			break;
563 		printk("%s%02X", !(i % 4) ? " " : "", data[i]);
564 	}
565 	printk("\n");
566 #endif
567 }
568 
569 
570 static inline void debug_desc(u32 phys, struct desc *desc)
571 {
572 #if DEBUG_DESC
573 	printk(KERN_DEBUG "%X: %X %3X %3X %08X %X %X\n",
574 	       phys, desc->next, desc->buf_len, desc->pkt_len,
575 	       desc->data, desc->status, desc->error_count);
576 #endif
577 }
578 
579 static inline int queue_get_desc(unsigned int queue, struct port *port,
580 				 int is_tx)
581 {
582 	u32 phys, tab_phys, n_desc;
583 	struct desc *tab;
584 
585 	if (!(phys = qmgr_get_entry(queue)))
586 		return -1;
587 
588 	BUG_ON(phys & 0x1F);
589 	tab_phys = is_tx ? tx_desc_phys(port, 0) : rx_desc_phys(port, 0);
590 	tab = is_tx ? tx_desc_ptr(port, 0) : rx_desc_ptr(port, 0);
591 	n_desc = (phys - tab_phys) / sizeof(struct desc);
592 	BUG_ON(n_desc >= (is_tx ? TX_DESCS : RX_DESCS));
593 	debug_desc(phys, &tab[n_desc]);
594 	BUG_ON(tab[n_desc].next);
595 	return n_desc;
596 }
597 
598 static inline void queue_put_desc(unsigned int queue, u32 phys,
599 				  struct desc *desc)
600 {
601 	debug_desc(phys, desc);
602 	BUG_ON(phys & 0x1F);
603 	qmgr_put_entry(queue, phys);
604 	/* Don't check for queue overflow here, we've allocated sufficient
605 	   length and queues >= 32 don't support this check anyway. */
606 }
607 
608 
609 static inline void dma_unmap_tx(struct port *port, struct desc *desc)
610 {
611 #ifdef __ARMEB__
612 	dma_unmap_single(&port->netdev->dev, desc->data,
613 			 desc->buf_len, DMA_TO_DEVICE);
614 #else
615 	dma_unmap_single(&port->netdev->dev, desc->data & ~3,
616 			 ALIGN((desc->data & 3) + desc->buf_len, 4),
617 			 DMA_TO_DEVICE);
618 #endif
619 }
620 
621 
622 static void hss_hdlc_set_carrier(void *pdev, int carrier)
623 {
624 	struct net_device *netdev = pdev;
625 	struct port *port = dev_to_port(netdev);
626 	unsigned long flags;
627 
628 	spin_lock_irqsave(&npe_lock, flags);
629 	port->carrier = carrier;
630 	if (!port->loopback) {
631 		if (carrier)
632 			netif_carrier_on(netdev);
633 		else
634 			netif_carrier_off(netdev);
635 	}
636 	spin_unlock_irqrestore(&npe_lock, flags);
637 }
638 
639 static void hss_hdlc_rx_irq(void *pdev)
640 {
641 	struct net_device *dev = pdev;
642 	struct port *port = dev_to_port(dev);
643 
644 #if DEBUG_RX
645 	printk(KERN_DEBUG "%s: hss_hdlc_rx_irq\n", dev->name);
646 #endif
647 	qmgr_disable_irq(queue_ids[port->id].rx);
648 	napi_schedule(&port->napi);
649 }
650 
651 static int hss_hdlc_poll(struct napi_struct *napi, int budget)
652 {
653 	struct port *port = container_of(napi, struct port, napi);
654 	struct net_device *dev = port->netdev;
655 	unsigned int rxq = queue_ids[port->id].rx;
656 	unsigned int rxfreeq = queue_ids[port->id].rxfree;
657 	int received = 0;
658 
659 #if DEBUG_RX
660 	printk(KERN_DEBUG "%s: hss_hdlc_poll\n", dev->name);
661 #endif
662 
663 	while (received < budget) {
664 		struct sk_buff *skb;
665 		struct desc *desc;
666 		int n;
667 #ifdef __ARMEB__
668 		struct sk_buff *temp;
669 		u32 phys;
670 #endif
671 
672 		if ((n = queue_get_desc(rxq, port, 0)) < 0) {
673 #if DEBUG_RX
674 			printk(KERN_DEBUG "%s: hss_hdlc_poll"
675 			       " napi_complete\n", dev->name);
676 #endif
677 			napi_complete(napi);
678 			qmgr_enable_irq(rxq);
679 			if (!qmgr_stat_empty(rxq) &&
680 			    napi_reschedule(napi)) {
681 #if DEBUG_RX
682 				printk(KERN_DEBUG "%s: hss_hdlc_poll"
683 				       " napi_reschedule succeeded\n",
684 				       dev->name);
685 #endif
686 				qmgr_disable_irq(rxq);
687 				continue;
688 			}
689 #if DEBUG_RX
690 			printk(KERN_DEBUG "%s: hss_hdlc_poll all done\n",
691 			       dev->name);
692 #endif
693 			return received; /* all work done */
694 		}
695 
696 		desc = rx_desc_ptr(port, n);
697 #if 0 /* FIXME - error_count counts modulo 256, perhaps we should use it */
698 		if (desc->error_count)
699 			printk(KERN_DEBUG "%s: hss_hdlc_poll status 0x%02X"
700 			       " errors %u\n", dev->name, desc->status,
701 			       desc->error_count);
702 #endif
703 		skb = NULL;
704 		switch (desc->status) {
705 		case 0:
706 #ifdef __ARMEB__
707 			if ((skb = netdev_alloc_skb(dev, RX_SIZE)) != NULL) {
708 				phys = dma_map_single(&dev->dev, skb->data,
709 						      RX_SIZE,
710 						      DMA_FROM_DEVICE);
711 				if (dma_mapping_error(&dev->dev, phys)) {
712 					dev_kfree_skb(skb);
713 					skb = NULL;
714 				}
715 			}
716 #else
717 			skb = netdev_alloc_skb(dev, desc->pkt_len);
718 #endif
719 			if (!skb)
720 				dev->stats.rx_dropped++;
721 			break;
722 		case ERR_HDLC_ALIGN:
723 		case ERR_HDLC_ABORT:
724 			dev->stats.rx_frame_errors++;
725 			dev->stats.rx_errors++;
726 			break;
727 		case ERR_HDLC_FCS:
728 			dev->stats.rx_crc_errors++;
729 			dev->stats.rx_errors++;
730 			break;
731 		case ERR_HDLC_TOO_LONG:
732 			dev->stats.rx_length_errors++;
733 			dev->stats.rx_errors++;
734 			break;
735 		default:	/* FIXME - remove printk */
736 			netdev_err(dev, "hss_hdlc_poll: status 0x%02X errors %u\n",
737 				   desc->status, desc->error_count);
738 			dev->stats.rx_errors++;
739 		}
740 
741 		if (!skb) {
742 			/* put the desc back on RX-ready queue */
743 			desc->buf_len = RX_SIZE;
744 			desc->pkt_len = desc->status = 0;
745 			queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
746 			continue;
747 		}
748 
749 		/* process received frame */
750 #ifdef __ARMEB__
751 		temp = skb;
752 		skb = port->rx_buff_tab[n];
753 		dma_unmap_single(&dev->dev, desc->data,
754 				 RX_SIZE, DMA_FROM_DEVICE);
755 #else
756 		dma_sync_single_for_cpu(&dev->dev, desc->data,
757 					RX_SIZE, DMA_FROM_DEVICE);
758 		memcpy_swab32((u32 *)skb->data, (u32 *)port->rx_buff_tab[n],
759 			      ALIGN(desc->pkt_len, 4) / 4);
760 #endif
761 		skb_put(skb, desc->pkt_len);
762 
763 		debug_pkt(dev, "hss_hdlc_poll", skb->data, skb->len);
764 
765 		skb->protocol = hdlc_type_trans(skb, dev);
766 		dev->stats.rx_packets++;
767 		dev->stats.rx_bytes += skb->len;
768 		netif_receive_skb(skb);
769 
770 		/* put the new buffer on RX-free queue */
771 #ifdef __ARMEB__
772 		port->rx_buff_tab[n] = temp;
773 		desc->data = phys;
774 #endif
775 		desc->buf_len = RX_SIZE;
776 		desc->pkt_len = 0;
777 		queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
778 		received++;
779 	}
780 #if DEBUG_RX
781 	printk(KERN_DEBUG "hss_hdlc_poll: end, not all work done\n");
782 #endif
783 	return received;	/* not all work done */
784 }
785 
786 
787 static void hss_hdlc_txdone_irq(void *pdev)
788 {
789 	struct net_device *dev = pdev;
790 	struct port *port = dev_to_port(dev);
791 	int n_desc;
792 
793 #if DEBUG_TX
794 	printk(KERN_DEBUG DRV_NAME ": hss_hdlc_txdone_irq\n");
795 #endif
796 	while ((n_desc = queue_get_desc(queue_ids[port->id].txdone,
797 					port, 1)) >= 0) {
798 		struct desc *desc;
799 		int start;
800 
801 		desc = tx_desc_ptr(port, n_desc);
802 
803 		dev->stats.tx_packets++;
804 		dev->stats.tx_bytes += desc->pkt_len;
805 
806 		dma_unmap_tx(port, desc);
807 #if DEBUG_TX
808 		printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq free %p\n",
809 		       dev->name, port->tx_buff_tab[n_desc]);
810 #endif
811 		free_buffer_irq(port->tx_buff_tab[n_desc]);
812 		port->tx_buff_tab[n_desc] = NULL;
813 
814 		start = qmgr_stat_below_low_watermark(port->plat->txreadyq);
815 		queue_put_desc(port->plat->txreadyq,
816 			       tx_desc_phys(port, n_desc), desc);
817 		if (start) { /* TX-ready queue was empty */
818 #if DEBUG_TX
819 			printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq xmit"
820 			       " ready\n", dev->name);
821 #endif
822 			netif_wake_queue(dev);
823 		}
824 	}
825 }
826 
827 static int hss_hdlc_xmit(struct sk_buff *skb, struct net_device *dev)
828 {
829 	struct port *port = dev_to_port(dev);
830 	unsigned int txreadyq = port->plat->txreadyq;
831 	int len, offset, bytes, n;
832 	void *mem;
833 	u32 phys;
834 	struct desc *desc;
835 
836 #if DEBUG_TX
837 	printk(KERN_DEBUG "%s: hss_hdlc_xmit\n", dev->name);
838 #endif
839 
840 	if (unlikely(skb->len > HDLC_MAX_MRU)) {
841 		dev_kfree_skb(skb);
842 		dev->stats.tx_errors++;
843 		return NETDEV_TX_OK;
844 	}
845 
846 	debug_pkt(dev, "hss_hdlc_xmit", skb->data, skb->len);
847 
848 	len = skb->len;
849 #ifdef __ARMEB__
850 	offset = 0; /* no need to keep alignment */
851 	bytes = len;
852 	mem = skb->data;
853 #else
854 	offset = (int)skb->data & 3; /* keep 32-bit alignment */
855 	bytes = ALIGN(offset + len, 4);
856 	if (!(mem = kmalloc(bytes, GFP_ATOMIC))) {
857 		dev_kfree_skb(skb);
858 		dev->stats.tx_dropped++;
859 		return NETDEV_TX_OK;
860 	}
861 	memcpy_swab32(mem, (u32 *)((int)skb->data & ~3), bytes / 4);
862 	dev_kfree_skb(skb);
863 #endif
864 
865 	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
866 	if (dma_mapping_error(&dev->dev, phys)) {
867 #ifdef __ARMEB__
868 		dev_kfree_skb(skb);
869 #else
870 		kfree(mem);
871 #endif
872 		dev->stats.tx_dropped++;
873 		return NETDEV_TX_OK;
874 	}
875 
876 	n = queue_get_desc(txreadyq, port, 1);
877 	BUG_ON(n < 0);
878 	desc = tx_desc_ptr(port, n);
879 
880 #ifdef __ARMEB__
881 	port->tx_buff_tab[n] = skb;
882 #else
883 	port->tx_buff_tab[n] = mem;
884 #endif
885 	desc->data = phys + offset;
886 	desc->buf_len = desc->pkt_len = len;
887 
888 	wmb();
889 	queue_put_desc(queue_ids[port->id].tx, tx_desc_phys(port, n), desc);
890 
891 	if (qmgr_stat_below_low_watermark(txreadyq)) { /* empty */
892 #if DEBUG_TX
893 		printk(KERN_DEBUG "%s: hss_hdlc_xmit queue full\n", dev->name);
894 #endif
895 		netif_stop_queue(dev);
896 		/* we could miss TX ready interrupt */
897 		if (!qmgr_stat_below_low_watermark(txreadyq)) {
898 #if DEBUG_TX
899 			printk(KERN_DEBUG "%s: hss_hdlc_xmit ready again\n",
900 			       dev->name);
901 #endif
902 			netif_wake_queue(dev);
903 		}
904 	}
905 
906 #if DEBUG_TX
907 	printk(KERN_DEBUG "%s: hss_hdlc_xmit end\n", dev->name);
908 #endif
909 	return NETDEV_TX_OK;
910 }
911 
912 
913 static int request_hdlc_queues(struct port *port)
914 {
915 	int err;
916 
917 	err = qmgr_request_queue(queue_ids[port->id].rxfree, RX_DESCS, 0, 0,
918 				 "%s:RX-free", port->netdev->name);
919 	if (err)
920 		return err;
921 
922 	err = qmgr_request_queue(queue_ids[port->id].rx, RX_DESCS, 0, 0,
923 				 "%s:RX", port->netdev->name);
924 	if (err)
925 		goto rel_rxfree;
926 
927 	err = qmgr_request_queue(queue_ids[port->id].tx, TX_DESCS, 0, 0,
928 				 "%s:TX", port->netdev->name);
929 	if (err)
930 		goto rel_rx;
931 
932 	err = qmgr_request_queue(port->plat->txreadyq, TX_DESCS, 0, 0,
933 				 "%s:TX-ready", port->netdev->name);
934 	if (err)
935 		goto rel_tx;
936 
937 	err = qmgr_request_queue(queue_ids[port->id].txdone, TX_DESCS, 0, 0,
938 				 "%s:TX-done", port->netdev->name);
939 	if (err)
940 		goto rel_txready;
941 	return 0;
942 
943 rel_txready:
944 	qmgr_release_queue(port->plat->txreadyq);
945 rel_tx:
946 	qmgr_release_queue(queue_ids[port->id].tx);
947 rel_rx:
948 	qmgr_release_queue(queue_ids[port->id].rx);
949 rel_rxfree:
950 	qmgr_release_queue(queue_ids[port->id].rxfree);
951 	printk(KERN_DEBUG "%s: unable to request hardware queues\n",
952 	       port->netdev->name);
953 	return err;
954 }
955 
956 static void release_hdlc_queues(struct port *port)
957 {
958 	qmgr_release_queue(queue_ids[port->id].rxfree);
959 	qmgr_release_queue(queue_ids[port->id].rx);
960 	qmgr_release_queue(queue_ids[port->id].txdone);
961 	qmgr_release_queue(queue_ids[port->id].tx);
962 	qmgr_release_queue(port->plat->txreadyq);
963 }
964 
965 static int init_hdlc_queues(struct port *port)
966 {
967 	int i;
968 
969 	if (!ports_open) {
970 		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
971 					   POOL_ALLOC_SIZE, 32, 0);
972 		if (!dma_pool)
973 			return -ENOMEM;
974 	}
975 
976 	if (!(port->desc_tab = dma_pool_alloc(dma_pool, GFP_KERNEL,
977 					      &port->desc_tab_phys)))
978 		return -ENOMEM;
979 	memset(port->desc_tab, 0, POOL_ALLOC_SIZE);
980 	memset(port->rx_buff_tab, 0, sizeof(port->rx_buff_tab)); /* tables */
981 	memset(port->tx_buff_tab, 0, sizeof(port->tx_buff_tab));
982 
983 	/* Setup RX buffers */
984 	for (i = 0; i < RX_DESCS; i++) {
985 		struct desc *desc = rx_desc_ptr(port, i);
986 		buffer_t *buff;
987 		void *data;
988 #ifdef __ARMEB__
989 		if (!(buff = netdev_alloc_skb(port->netdev, RX_SIZE)))
990 			return -ENOMEM;
991 		data = buff->data;
992 #else
993 		if (!(buff = kmalloc(RX_SIZE, GFP_KERNEL)))
994 			return -ENOMEM;
995 		data = buff;
996 #endif
997 		desc->buf_len = RX_SIZE;
998 		desc->data = dma_map_single(&port->netdev->dev, data,
999 					    RX_SIZE, DMA_FROM_DEVICE);
1000 		if (dma_mapping_error(&port->netdev->dev, desc->data)) {
1001 			free_buffer(buff);
1002 			return -EIO;
1003 		}
1004 		port->rx_buff_tab[i] = buff;
1005 	}
1006 
1007 	return 0;
1008 }
1009 
1010 static void destroy_hdlc_queues(struct port *port)
1011 {
1012 	int i;
1013 
1014 	if (port->desc_tab) {
1015 		for (i = 0; i < RX_DESCS; i++) {
1016 			struct desc *desc = rx_desc_ptr(port, i);
1017 			buffer_t *buff = port->rx_buff_tab[i];
1018 			if (buff) {
1019 				dma_unmap_single(&port->netdev->dev,
1020 						 desc->data, RX_SIZE,
1021 						 DMA_FROM_DEVICE);
1022 				free_buffer(buff);
1023 			}
1024 		}
1025 		for (i = 0; i < TX_DESCS; i++) {
1026 			struct desc *desc = tx_desc_ptr(port, i);
1027 			buffer_t *buff = port->tx_buff_tab[i];
1028 			if (buff) {
1029 				dma_unmap_tx(port, desc);
1030 				free_buffer(buff);
1031 			}
1032 		}
1033 		dma_pool_free(dma_pool, port->desc_tab, port->desc_tab_phys);
1034 		port->desc_tab = NULL;
1035 	}
1036 
1037 	if (!ports_open && dma_pool) {
1038 		dma_pool_destroy(dma_pool);
1039 		dma_pool = NULL;
1040 	}
1041 }
1042 
1043 static int hss_hdlc_open(struct net_device *dev)
1044 {
1045 	struct port *port = dev_to_port(dev);
1046 	unsigned long flags;
1047 	int i, err = 0;
1048 
1049 	if ((err = hdlc_open(dev)))
1050 		return err;
1051 
1052 	if ((err = hss_load_firmware(port)))
1053 		goto err_hdlc_close;
1054 
1055 	if ((err = request_hdlc_queues(port)))
1056 		goto err_hdlc_close;
1057 
1058 	if ((err = init_hdlc_queues(port)))
1059 		goto err_destroy_queues;
1060 
1061 	spin_lock_irqsave(&npe_lock, flags);
1062 	if (port->plat->open)
1063 		if ((err = port->plat->open(port->id, dev,
1064 					    hss_hdlc_set_carrier)))
1065 			goto err_unlock;
1066 	spin_unlock_irqrestore(&npe_lock, flags);
1067 
1068 	/* Populate queues with buffers, no failure after this point */
1069 	for (i = 0; i < TX_DESCS; i++)
1070 		queue_put_desc(port->plat->txreadyq,
1071 			       tx_desc_phys(port, i), tx_desc_ptr(port, i));
1072 
1073 	for (i = 0; i < RX_DESCS; i++)
1074 		queue_put_desc(queue_ids[port->id].rxfree,
1075 			       rx_desc_phys(port, i), rx_desc_ptr(port, i));
1076 
1077 	napi_enable(&port->napi);
1078 	netif_start_queue(dev);
1079 
1080 	qmgr_set_irq(queue_ids[port->id].rx, QUEUE_IRQ_SRC_NOT_EMPTY,
1081 		     hss_hdlc_rx_irq, dev);
1082 
1083 	qmgr_set_irq(queue_ids[port->id].txdone, QUEUE_IRQ_SRC_NOT_EMPTY,
1084 		     hss_hdlc_txdone_irq, dev);
1085 	qmgr_enable_irq(queue_ids[port->id].txdone);
1086 
1087 	ports_open++;
1088 
1089 	hss_set_hdlc_cfg(port);
1090 	hss_config(port);
1091 
1092 	hss_start_hdlc(port);
1093 
1094 	/* we may already have RX data, enables IRQ */
1095 	napi_schedule(&port->napi);
1096 	return 0;
1097 
1098 err_unlock:
1099 	spin_unlock_irqrestore(&npe_lock, flags);
1100 err_destroy_queues:
1101 	destroy_hdlc_queues(port);
1102 	release_hdlc_queues(port);
1103 err_hdlc_close:
1104 	hdlc_close(dev);
1105 	return err;
1106 }
1107 
1108 static int hss_hdlc_close(struct net_device *dev)
1109 {
1110 	struct port *port = dev_to_port(dev);
1111 	unsigned long flags;
1112 	int i, buffs = RX_DESCS; /* allocated RX buffers */
1113 
1114 	spin_lock_irqsave(&npe_lock, flags);
1115 	ports_open--;
1116 	qmgr_disable_irq(queue_ids[port->id].rx);
1117 	netif_stop_queue(dev);
1118 	napi_disable(&port->napi);
1119 
1120 	hss_stop_hdlc(port);
1121 
1122 	while (queue_get_desc(queue_ids[port->id].rxfree, port, 0) >= 0)
1123 		buffs--;
1124 	while (queue_get_desc(queue_ids[port->id].rx, port, 0) >= 0)
1125 		buffs--;
1126 
1127 	if (buffs)
1128 		netdev_crit(dev, "unable to drain RX queue, %i buffer(s) left in NPE\n",
1129 			    buffs);
1130 
1131 	buffs = TX_DESCS;
1132 	while (queue_get_desc(queue_ids[port->id].tx, port, 1) >= 0)
1133 		buffs--; /* cancel TX */
1134 
1135 	i = 0;
1136 	do {
1137 		while (queue_get_desc(port->plat->txreadyq, port, 1) >= 0)
1138 			buffs--;
1139 		if (!buffs)
1140 			break;
1141 	} while (++i < MAX_CLOSE_WAIT);
1142 
1143 	if (buffs)
1144 		netdev_crit(dev, "unable to drain TX queue, %i buffer(s) left in NPE\n",
1145 			    buffs);
1146 #if DEBUG_CLOSE
1147 	if (!buffs)
1148 		printk(KERN_DEBUG "Draining TX queues took %i cycles\n", i);
1149 #endif
1150 	qmgr_disable_irq(queue_ids[port->id].txdone);
1151 
1152 	if (port->plat->close)
1153 		port->plat->close(port->id, dev);
1154 	spin_unlock_irqrestore(&npe_lock, flags);
1155 
1156 	destroy_hdlc_queues(port);
1157 	release_hdlc_queues(port);
1158 	hdlc_close(dev);
1159 	return 0;
1160 }
1161 
1162 
1163 static int hss_hdlc_attach(struct net_device *dev, unsigned short encoding,
1164 			   unsigned short parity)
1165 {
1166 	struct port *port = dev_to_port(dev);
1167 
1168 	if (encoding != ENCODING_NRZ)
1169 		return -EINVAL;
1170 
1171 	switch(parity) {
1172 	case PARITY_CRC16_PR1_CCITT:
1173 		port->hdlc_cfg = 0;
1174 		return 0;
1175 
1176 	case PARITY_CRC32_PR1_CCITT:
1177 		port->hdlc_cfg = PKT_HDLC_CRC_32;
1178 		return 0;
1179 
1180 	default:
1181 		return -EINVAL;
1182 	}
1183 }
1184 
1185 static u32 check_clock(u32 rate, u32 a, u32 b, u32 c,
1186 		       u32 *best, u32 *best_diff, u32 *reg)
1187 {
1188 	/* a is 10-bit, b is 10-bit, c is 12-bit */
1189 	u64 new_rate;
1190 	u32 new_diff;
1191 
1192 	new_rate = ixp4xx_timer_freq * (u64)(c + 1);
1193 	do_div(new_rate, a * (c + 1) + b + 1);
1194 	new_diff = abs((u32)new_rate - rate);
1195 
1196 	if (new_diff < *best_diff) {
1197 		*best = new_rate;
1198 		*best_diff = new_diff;
1199 		*reg = (a << 22) | (b << 12) | c;
1200 	}
1201 	return new_diff;
1202 }
1203 
1204 static void find_best_clock(u32 rate, u32 *best, u32 *reg)
1205 {
1206 	u32 a, b, diff = 0xFFFFFFFF;
1207 
1208 	a = ixp4xx_timer_freq / rate;
1209 
1210 	if (a > 0x3FF) { /* 10-bit value - we can go as slow as ca. 65 kb/s */
1211 		check_clock(rate, 0x3FF, 1, 1, best, &diff, reg);
1212 		return;
1213 	}
1214 	if (a == 0) { /* > 66.666 MHz */
1215 		a = 1; /* minimum divider is 1 (a = 0, b = 1, c = 1) */
1216 		rate = ixp4xx_timer_freq;
1217 	}
1218 
1219 	if (rate * a == ixp4xx_timer_freq) { /* don't divide by 0 later */
1220 		check_clock(rate, a - 1, 1, 1, best, &diff, reg);
1221 		return;
1222 	}
1223 
1224 	for (b = 0; b < 0x400; b++) {
1225 		u64 c = (b + 1) * (u64)rate;
1226 		do_div(c, ixp4xx_timer_freq - rate * a);
1227 		c--;
1228 		if (c >= 0xFFF) { /* 12-bit - no need to check more 'b's */
1229 			if (b == 0 && /* also try a bit higher rate */
1230 			    !check_clock(rate, a - 1, 1, 1, best, &diff, reg))
1231 				return;
1232 			check_clock(rate, a, b, 0xFFF, best, &diff, reg);
1233 			return;
1234 		}
1235 		if (!check_clock(rate, a, b, c, best, &diff, reg))
1236 			return;
1237 		if (!check_clock(rate, a, b, c + 1, best, &diff, reg))
1238 			return;
1239 	}
1240 }
1241 
1242 static int hss_hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1243 {
1244 	const size_t size = sizeof(sync_serial_settings);
1245 	sync_serial_settings new_line;
1246 	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
1247 	struct port *port = dev_to_port(dev);
1248 	unsigned long flags;
1249 	int clk;
1250 
1251 	if (cmd != SIOCWANDEV)
1252 		return hdlc_ioctl(dev, ifr, cmd);
1253 
1254 	switch(ifr->ifr_settings.type) {
1255 	case IF_GET_IFACE:
1256 		ifr->ifr_settings.type = IF_IFACE_V35;
1257 		if (ifr->ifr_settings.size < size) {
1258 			ifr->ifr_settings.size = size; /* data size wanted */
1259 			return -ENOBUFS;
1260 		}
1261 		memset(&new_line, 0, sizeof(new_line));
1262 		new_line.clock_type = port->clock_type;
1263 		new_line.clock_rate = port->clock_rate;
1264 		new_line.loopback = port->loopback;
1265 		if (copy_to_user(line, &new_line, size))
1266 			return -EFAULT;
1267 		return 0;
1268 
1269 	case IF_IFACE_SYNC_SERIAL:
1270 	case IF_IFACE_V35:
1271 		if(!capable(CAP_NET_ADMIN))
1272 			return -EPERM;
1273 		if (copy_from_user(&new_line, line, size))
1274 			return -EFAULT;
1275 
1276 		clk = new_line.clock_type;
1277 		if (port->plat->set_clock)
1278 			clk = port->plat->set_clock(port->id, clk);
1279 
1280 		if (clk != CLOCK_EXT && clk != CLOCK_INT)
1281 			return -EINVAL;	/* No such clock setting */
1282 
1283 		if (new_line.loopback != 0 && new_line.loopback != 1)
1284 			return -EINVAL;
1285 
1286 		port->clock_type = clk; /* Update settings */
1287 		if (clk == CLOCK_INT)
1288 			find_best_clock(new_line.clock_rate, &port->clock_rate,
1289 					&port->clock_reg);
1290 		else {
1291 			port->clock_rate = 0;
1292 			port->clock_reg = CLK42X_SPEED_2048KHZ;
1293 		}
1294 		port->loopback = new_line.loopback;
1295 
1296 		spin_lock_irqsave(&npe_lock, flags);
1297 
1298 		if (dev->flags & IFF_UP)
1299 			hss_config(port);
1300 
1301 		if (port->loopback || port->carrier)
1302 			netif_carrier_on(port->netdev);
1303 		else
1304 			netif_carrier_off(port->netdev);
1305 		spin_unlock_irqrestore(&npe_lock, flags);
1306 
1307 		return 0;
1308 
1309 	default:
1310 		return hdlc_ioctl(dev, ifr, cmd);
1311 	}
1312 }
1313 
1314 /*****************************************************************************
1315  * initialization
1316  ****************************************************************************/
1317 
1318 static const struct net_device_ops hss_hdlc_ops = {
1319 	.ndo_open       = hss_hdlc_open,
1320 	.ndo_stop       = hss_hdlc_close,
1321 	.ndo_start_xmit = hdlc_start_xmit,
1322 	.ndo_do_ioctl   = hss_hdlc_ioctl,
1323 };
1324 
1325 static int hss_init_one(struct platform_device *pdev)
1326 {
1327 	struct port *port;
1328 	struct net_device *dev;
1329 	hdlc_device *hdlc;
1330 	int err;
1331 
1332 	if ((port = kzalloc(sizeof(*port), GFP_KERNEL)) == NULL)
1333 		return -ENOMEM;
1334 
1335 	if ((port->npe = npe_request(0)) == NULL) {
1336 		err = -ENODEV;
1337 		goto err_free;
1338 	}
1339 
1340 	if ((port->netdev = dev = alloc_hdlcdev(port)) == NULL) {
1341 		err = -ENOMEM;
1342 		goto err_plat;
1343 	}
1344 
1345 	SET_NETDEV_DEV(dev, &pdev->dev);
1346 	hdlc = dev_to_hdlc(dev);
1347 	hdlc->attach = hss_hdlc_attach;
1348 	hdlc->xmit = hss_hdlc_xmit;
1349 	dev->netdev_ops = &hss_hdlc_ops;
1350 	dev->tx_queue_len = 100;
1351 	port->clock_type = CLOCK_EXT;
1352 	port->clock_rate = 0;
1353 	port->clock_reg = CLK42X_SPEED_2048KHZ;
1354 	port->id = pdev->id;
1355 	port->dev = &pdev->dev;
1356 	port->plat = pdev->dev.platform_data;
1357 	netif_napi_add(dev, &port->napi, hss_hdlc_poll, NAPI_WEIGHT);
1358 
1359 	if ((err = register_hdlc_device(dev)))
1360 		goto err_free_netdev;
1361 
1362 	platform_set_drvdata(pdev, port);
1363 
1364 	netdev_info(dev, "initialized\n");
1365 	return 0;
1366 
1367 err_free_netdev:
1368 	free_netdev(dev);
1369 err_plat:
1370 	npe_release(port->npe);
1371 err_free:
1372 	kfree(port);
1373 	return err;
1374 }
1375 
1376 static int hss_remove_one(struct platform_device *pdev)
1377 {
1378 	struct port *port = platform_get_drvdata(pdev);
1379 
1380 	unregister_hdlc_device(port->netdev);
1381 	free_netdev(port->netdev);
1382 	npe_release(port->npe);
1383 	kfree(port);
1384 	return 0;
1385 }
1386 
1387 static struct platform_driver ixp4xx_hss_driver = {
1388 	.driver.name	= DRV_NAME,
1389 	.probe		= hss_init_one,
1390 	.remove		= hss_remove_one,
1391 };
1392 
1393 static int __init hss_init_module(void)
1394 {
1395 	if ((ixp4xx_read_feature_bits() &
1396 	     (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) !=
1397 	    (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS))
1398 		return -ENODEV;
1399 
1400 	spin_lock_init(&npe_lock);
1401 
1402 	return platform_driver_register(&ixp4xx_hss_driver);
1403 }
1404 
1405 static void __exit hss_cleanup_module(void)
1406 {
1407 	platform_driver_unregister(&ixp4xx_hss_driver);
1408 }
1409 
1410 MODULE_AUTHOR("Krzysztof Halasa");
1411 MODULE_DESCRIPTION("Intel IXP4xx HSS driver");
1412 MODULE_LICENSE("GPL v2");
1413 MODULE_ALIAS("platform:ixp4xx_hss");
1414 module_init(hss_init_module);
1415 module_exit(hss_cleanup_module);
1416