xref: /openbmc/linux/drivers/net/wan/ixp4xx_hss.c (revision 78560d41)
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/platform_data/wan_ixp4xx_hss.h>
21 #include <linux/poll.h>
22 #include <linux/slab.h>
23 #include <linux/soc/ixp4xx/npe.h>
24 #include <linux/soc/ixp4xx/qmgr.h>
25 
26 #define DEBUG_DESC		0
27 #define DEBUG_RX		0
28 #define DEBUG_TX		0
29 #define DEBUG_PKT_BYTES		0
30 #define DEBUG_CLOSE		0
31 
32 #define DRV_NAME		"ixp4xx_hss"
33 
34 #define PKT_EXTRA_FLAGS		0 /* orig 1 */
35 #define PKT_NUM_PIPES		1 /* 1, 2 or 4 */
36 #define PKT_PIPE_FIFO_SIZEW	4 /* total 4 dwords per HSS */
37 
38 #define RX_DESCS		16 /* also length of all RX queues */
39 #define TX_DESCS		16 /* also length of all TX queues */
40 
41 #define POOL_ALLOC_SIZE		(sizeof(struct desc) * (RX_DESCS + TX_DESCS))
42 #define RX_SIZE			(HDLC_MAX_MRU + 4) /* NPE needs more space */
43 #define MAX_CLOSE_WAIT		1000 /* microseconds */
44 #define HSS_COUNT		2
45 #define FRAME_SIZE		256 /* doesn't matter at this point */
46 #define FRAME_OFFSET		0
47 #define MAX_CHANNELS		(FRAME_SIZE / 8)
48 
49 #define NAPI_WEIGHT		16
50 
51 /* Queue IDs */
52 #define HSS0_CHL_RXTRIG_QUEUE	12	/* orig size = 32 dwords */
53 #define HSS0_PKT_RX_QUEUE	13	/* orig size = 32 dwords */
54 #define HSS0_PKT_TX0_QUEUE	14	/* orig size = 16 dwords */
55 #define HSS0_PKT_TX1_QUEUE	15
56 #define HSS0_PKT_TX2_QUEUE	16
57 #define HSS0_PKT_TX3_QUEUE	17
58 #define HSS0_PKT_RXFREE0_QUEUE	18	/* orig size = 16 dwords */
59 #define HSS0_PKT_RXFREE1_QUEUE	19
60 #define HSS0_PKT_RXFREE2_QUEUE	20
61 #define HSS0_PKT_RXFREE3_QUEUE	21
62 #define HSS0_PKT_TXDONE_QUEUE	22	/* orig size = 64 dwords */
63 
64 #define HSS1_CHL_RXTRIG_QUEUE	10
65 #define HSS1_PKT_RX_QUEUE	0
66 #define HSS1_PKT_TX0_QUEUE	5
67 #define HSS1_PKT_TX1_QUEUE	6
68 #define HSS1_PKT_TX2_QUEUE	7
69 #define HSS1_PKT_TX3_QUEUE	8
70 #define HSS1_PKT_RXFREE0_QUEUE	1
71 #define HSS1_PKT_RXFREE1_QUEUE	2
72 #define HSS1_PKT_RXFREE2_QUEUE	3
73 #define HSS1_PKT_RXFREE3_QUEUE	4
74 #define HSS1_PKT_TXDONE_QUEUE	9
75 
76 #define NPE_PKT_MODE_HDLC		0
77 #define NPE_PKT_MODE_RAW		1
78 #define NPE_PKT_MODE_56KMODE		2
79 #define NPE_PKT_MODE_56KENDIAN_MSB	4
80 
81 /* PKT_PIPE_HDLC_CFG_WRITE flags */
82 #define PKT_HDLC_IDLE_ONES		0x1 /* default = flags */
83 #define PKT_HDLC_CRC_32			0x2 /* default = CRC-16 */
84 #define PKT_HDLC_MSB_ENDIAN		0x4 /* default = LE */
85 
86 
87 /* hss_config, PCRs */
88 /* Frame sync sampling, default = active low */
89 #define PCR_FRM_SYNC_ACTIVE_HIGH	0x40000000
90 #define PCR_FRM_SYNC_FALLINGEDGE	0x80000000
91 #define PCR_FRM_SYNC_RISINGEDGE		0xC0000000
92 
93 /* Frame sync pin: input (default) or output generated off a given clk edge */
94 #define PCR_FRM_SYNC_OUTPUT_FALLING	0x20000000
95 #define PCR_FRM_SYNC_OUTPUT_RISING	0x30000000
96 
97 /* Frame and data clock sampling on edge, default = falling */
98 #define PCR_FCLK_EDGE_RISING		0x08000000
99 #define PCR_DCLK_EDGE_RISING		0x04000000
100 
101 /* Clock direction, default = input */
102 #define PCR_SYNC_CLK_DIR_OUTPUT		0x02000000
103 
104 /* Generate/Receive frame pulses, default = enabled */
105 #define PCR_FRM_PULSE_DISABLED		0x01000000
106 
107  /* Data rate is full (default) or half the configured clk speed */
108 #define PCR_HALF_CLK_RATE		0x00200000
109 
110 /* Invert data between NPE and HSS FIFOs? (default = no) */
111 #define PCR_DATA_POLARITY_INVERT	0x00100000
112 
113 /* TX/RX endianness, default = LSB */
114 #define PCR_MSB_ENDIAN			0x00080000
115 
116 /* Normal (default) / open drain mode (TX only) */
117 #define PCR_TX_PINS_OPEN_DRAIN		0x00040000
118 
119 /* No framing bit transmitted and expected on RX? (default = framing bit) */
120 #define PCR_SOF_NO_FBIT			0x00020000
121 
122 /* Drive data pins? */
123 #define PCR_TX_DATA_ENABLE		0x00010000
124 
125 /* Voice 56k type: drive the data pins low (default), high, high Z */
126 #define PCR_TX_V56K_HIGH		0x00002000
127 #define PCR_TX_V56K_HIGH_IMP		0x00004000
128 
129 /* Unassigned type: drive the data pins low (default), high, high Z */
130 #define PCR_TX_UNASS_HIGH		0x00000800
131 #define PCR_TX_UNASS_HIGH_IMP		0x00001000
132 
133 /* T1 @ 1.544MHz only: Fbit dictated in FIFO (default) or high Z */
134 #define PCR_TX_FB_HIGH_IMP		0x00000400
135 
136 /* 56k data endiannes - which bit unused: high (default) or low */
137 #define PCR_TX_56KE_BIT_0_UNUSED	0x00000200
138 
139 /* 56k data transmission type: 32/8 bit data (default) or 56K data */
140 #define PCR_TX_56KS_56K_DATA		0x00000100
141 
142 /* hss_config, cCR */
143 /* Number of packetized clients, default = 1 */
144 #define CCR_NPE_HFIFO_2_HDLC		0x04000000
145 #define CCR_NPE_HFIFO_3_OR_4HDLC	0x08000000
146 
147 /* default = no loopback */
148 #define CCR_LOOPBACK			0x02000000
149 
150 /* HSS number, default = 0 (first) */
151 #define CCR_SECOND_HSS			0x01000000
152 
153 
154 /* hss_config, clkCR: main:10, num:10, denom:12 */
155 #define CLK42X_SPEED_EXP	((0x3FF << 22) | (  2 << 12) |   15) /*65 KHz*/
156 
157 #define CLK42X_SPEED_512KHZ	((  130 << 22) | (  2 << 12) |   15)
158 #define CLK42X_SPEED_1536KHZ	((   43 << 22) | ( 18 << 12) |   47)
159 #define CLK42X_SPEED_1544KHZ	((   43 << 22) | ( 33 << 12) |  192)
160 #define CLK42X_SPEED_2048KHZ	((   32 << 22) | ( 34 << 12) |   63)
161 #define CLK42X_SPEED_4096KHZ	((   16 << 22) | ( 34 << 12) |  127)
162 #define CLK42X_SPEED_8192KHZ	((    8 << 22) | ( 34 << 12) |  255)
163 
164 #define CLK46X_SPEED_512KHZ	((  130 << 22) | ( 24 << 12) |  127)
165 #define CLK46X_SPEED_1536KHZ	((   43 << 22) | (152 << 12) |  383)
166 #define CLK46X_SPEED_1544KHZ	((   43 << 22) | ( 66 << 12) |  385)
167 #define CLK46X_SPEED_2048KHZ	((   32 << 22) | (280 << 12) |  511)
168 #define CLK46X_SPEED_4096KHZ	((   16 << 22) | (280 << 12) | 1023)
169 #define CLK46X_SPEED_8192KHZ	((    8 << 22) | (280 << 12) | 2047)
170 
171 /*
172  * HSS_CONFIG_CLOCK_CR register consists of 3 parts:
173  *     A (10 bits), B (10 bits) and C (12 bits).
174  * IXP42x HSS clock generator operation (verified with an oscilloscope):
175  * Each clock bit takes 7.5 ns (1 / 133.xx MHz).
176  * The clock sequence consists of (C - B) states of 0s and 1s, each state is
177  * A bits wide. It's followed by (B + 1) states of 0s and 1s, each state is
178  * (A + 1) bits wide.
179  *
180  * The resulting average clock frequency (assuming 33.333 MHz oscillator) is:
181  * freq = 66.666 MHz / (A + (B + 1) / (C + 1))
182  * minimum freq = 66.666 MHz / (A + 1)
183  * maximum freq = 66.666 MHz / A
184  *
185  * Example: A = 2, B = 2, C = 7, CLOCK_CR register = 2 << 22 | 2 << 12 | 7
186  * freq = 66.666 MHz / (2 + (2 + 1) / (7 + 1)) = 28.07 MHz (Mb/s).
187  * The clock sequence is: 1100110011 (5 doubles) 000111000 (3 triples).
188  * The sequence takes (C - B) * A + (B + 1) * (A + 1) = 5 * 2 + 3 * 3 bits
189  * = 19 bits (each 7.5 ns long) = 142.5 ns (then the sequence repeats).
190  * The sequence consists of 4 complete clock periods, thus the average
191  * frequency (= clock rate) is 4 / 142.5 ns = 28.07 MHz (Mb/s).
192  * (max specified clock rate for IXP42x HSS is 8.192 Mb/s).
193  */
194 
195 /* hss_config, LUT entries */
196 #define TDMMAP_UNASSIGNED	0
197 #define TDMMAP_HDLC		1	/* HDLC - packetized */
198 #define TDMMAP_VOICE56K		2	/* Voice56K - 7-bit channelized */
199 #define TDMMAP_VOICE64K		3	/* Voice64K - 8-bit channelized */
200 
201 /* offsets into HSS config */
202 #define HSS_CONFIG_TX_PCR	0x00 /* port configuration registers */
203 #define HSS_CONFIG_RX_PCR	0x04
204 #define HSS_CONFIG_CORE_CR	0x08 /* loopback control, HSS# */
205 #define HSS_CONFIG_CLOCK_CR	0x0C /* clock generator control */
206 #define HSS_CONFIG_TX_FCR	0x10 /* frame configuration registers */
207 #define HSS_CONFIG_RX_FCR	0x14
208 #define HSS_CONFIG_TX_LUT	0x18 /* channel look-up tables */
209 #define HSS_CONFIG_RX_LUT	0x38
210 
211 
212 /* NPE command codes */
213 /* writes the ConfigWord value to the location specified by offset */
214 #define PORT_CONFIG_WRITE		0x40
215 
216 /* triggers the NPE to load the contents of the configuration table */
217 #define PORT_CONFIG_LOAD		0x41
218 
219 /* triggers the NPE to return an HssErrorReadResponse message */
220 #define PORT_ERROR_READ			0x42
221 
222 /* triggers the NPE to reset internal status and enable the HssPacketized
223    operation for the flow specified by pPipe */
224 #define PKT_PIPE_FLOW_ENABLE		0x50
225 #define PKT_PIPE_FLOW_DISABLE		0x51
226 #define PKT_NUM_PIPES_WRITE		0x52
227 #define PKT_PIPE_FIFO_SIZEW_WRITE	0x53
228 #define PKT_PIPE_HDLC_CFG_WRITE		0x54
229 #define PKT_PIPE_IDLE_PATTERN_WRITE	0x55
230 #define PKT_PIPE_RX_SIZE_WRITE		0x56
231 #define PKT_PIPE_MODE_WRITE		0x57
232 
233 /* HDLC packet status values - desc->status */
234 #define ERR_SHUTDOWN		1 /* stop or shutdown occurrence */
235 #define ERR_HDLC_ALIGN		2 /* HDLC alignment error */
236 #define ERR_HDLC_FCS		3 /* HDLC Frame Check Sum error */
237 #define ERR_RXFREE_Q_EMPTY	4 /* RX-free queue became empty while receiving
238 				     this packet (if buf_len < pkt_len) */
239 #define ERR_HDLC_TOO_LONG	5 /* HDLC frame size too long */
240 #define ERR_HDLC_ABORT		6 /* abort sequence received */
241 #define ERR_DISCONNECTING	7 /* disconnect is in progress */
242 
243 
244 #ifdef __ARMEB__
245 typedef struct sk_buff buffer_t;
246 #define free_buffer dev_kfree_skb
247 #define free_buffer_irq dev_consume_skb_irq
248 #else
249 typedef void buffer_t;
250 #define free_buffer kfree
251 #define free_buffer_irq kfree
252 #endif
253 
254 struct port {
255 	struct device *dev;
256 	struct npe *npe;
257 	struct net_device *netdev;
258 	struct napi_struct napi;
259 	struct hss_plat_info *plat;
260 	buffer_t *rx_buff_tab[RX_DESCS], *tx_buff_tab[TX_DESCS];
261 	struct desc *desc_tab;	/* coherent */
262 	dma_addr_t desc_tab_phys;
263 	unsigned int id;
264 	unsigned int clock_type, clock_rate, loopback;
265 	unsigned int initialized, carrier;
266 	u8 hdlc_cfg;
267 	u32 clock_reg;
268 };
269 
270 /* NPE message structure */
271 struct msg {
272 #ifdef __ARMEB__
273 	u8 cmd, unused, hss_port, index;
274 	union {
275 		struct { u8 data8a, data8b, data8c, data8d; };
276 		struct { u16 data16a, data16b; };
277 		struct { u32 data32; };
278 	};
279 #else
280 	u8 index, hss_port, unused, cmd;
281 	union {
282 		struct { u8 data8d, data8c, data8b, data8a; };
283 		struct { u16 data16b, data16a; };
284 		struct { u32 data32; };
285 	};
286 #endif
287 };
288 
289 /* HDLC packet descriptor */
290 struct desc {
291 	u32 next;		/* pointer to next buffer, unused */
292 
293 #ifdef __ARMEB__
294 	u16 buf_len;		/* buffer length */
295 	u16 pkt_len;		/* packet length */
296 	u32 data;		/* pointer to data buffer in RAM */
297 	u8 status;
298 	u8 error_count;
299 	u16 __reserved;
300 #else
301 	u16 pkt_len;		/* packet length */
302 	u16 buf_len;		/* buffer length */
303 	u32 data;		/* pointer to data buffer in RAM */
304 	u16 __reserved;
305 	u8 error_count;
306 	u8 status;
307 #endif
308 	u32 __reserved1[4];
309 };
310 
311 
312 #define rx_desc_phys(port, n)	((port)->desc_tab_phys +		\
313 				 (n) * sizeof(struct desc))
314 #define rx_desc_ptr(port, n)	(&(port)->desc_tab[n])
315 
316 #define tx_desc_phys(port, n)	((port)->desc_tab_phys +		\
317 				 ((n) + RX_DESCS) * sizeof(struct desc))
318 #define tx_desc_ptr(port, n)	(&(port)->desc_tab[(n) + RX_DESCS])
319 
320 /*****************************************************************************
321  * global variables
322  ****************************************************************************/
323 
324 static int ports_open;
325 static struct dma_pool *dma_pool;
326 static spinlock_t npe_lock;
327 
328 static const struct {
329 	int tx, txdone, rx, rxfree;
330 }queue_ids[2] = {{HSS0_PKT_TX0_QUEUE, HSS0_PKT_TXDONE_QUEUE, HSS0_PKT_RX_QUEUE,
331 		  HSS0_PKT_RXFREE0_QUEUE},
332 		 {HSS1_PKT_TX0_QUEUE, HSS1_PKT_TXDONE_QUEUE, HSS1_PKT_RX_QUEUE,
333 		  HSS1_PKT_RXFREE0_QUEUE},
334 };
335 
336 /*****************************************************************************
337  * utility functions
338  ****************************************************************************/
339 
340 static inline struct port* dev_to_port(struct net_device *dev)
341 {
342 	return dev_to_hdlc(dev)->priv;
343 }
344 
345 #ifndef __ARMEB__
346 static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
347 {
348 	int i;
349 	for (i = 0; i < cnt; i++)
350 		dest[i] = swab32(src[i]);
351 }
352 #endif
353 
354 /*****************************************************************************
355  * HSS access
356  ****************************************************************************/
357 
358 static void hss_npe_send(struct port *port, struct msg *msg, const char* what)
359 {
360 	u32 *val = (u32*)msg;
361 	if (npe_send_message(port->npe, msg, what)) {
362 		pr_crit("HSS-%i: unable to send command [%08X:%08X] to %s\n",
363 			port->id, val[0], val[1], npe_name(port->npe));
364 		BUG();
365 	}
366 }
367 
368 static void hss_config_set_lut(struct port *port)
369 {
370 	struct msg msg;
371 	int ch;
372 
373 	memset(&msg, 0, sizeof(msg));
374 	msg.cmd = PORT_CONFIG_WRITE;
375 	msg.hss_port = port->id;
376 
377 	for (ch = 0; ch < MAX_CHANNELS; ch++) {
378 		msg.data32 >>= 2;
379 		msg.data32 |= TDMMAP_HDLC << 30;
380 
381 		if (ch % 16 == 15) {
382 			msg.index = HSS_CONFIG_TX_LUT + ((ch / 4) & ~3);
383 			hss_npe_send(port, &msg, "HSS_SET_TX_LUT");
384 
385 			msg.index += HSS_CONFIG_RX_LUT - HSS_CONFIG_TX_LUT;
386 			hss_npe_send(port, &msg, "HSS_SET_RX_LUT");
387 		}
388 	}
389 }
390 
391 static void hss_config(struct port *port)
392 {
393 	struct msg msg;
394 
395 	memset(&msg, 0, sizeof(msg));
396 	msg.cmd = PORT_CONFIG_WRITE;
397 	msg.hss_port = port->id;
398 	msg.index = HSS_CONFIG_TX_PCR;
399 	msg.data32 = PCR_FRM_PULSE_DISABLED | PCR_MSB_ENDIAN |
400 		PCR_TX_DATA_ENABLE | PCR_SOF_NO_FBIT;
401 	if (port->clock_type == CLOCK_INT)
402 		msg.data32 |= PCR_SYNC_CLK_DIR_OUTPUT;
403 	hss_npe_send(port, &msg, "HSS_SET_TX_PCR");
404 
405 	msg.index = HSS_CONFIG_RX_PCR;
406 	msg.data32 ^= PCR_TX_DATA_ENABLE | PCR_DCLK_EDGE_RISING;
407 	hss_npe_send(port, &msg, "HSS_SET_RX_PCR");
408 
409 	memset(&msg, 0, sizeof(msg));
410 	msg.cmd = PORT_CONFIG_WRITE;
411 	msg.hss_port = port->id;
412 	msg.index = HSS_CONFIG_CORE_CR;
413 	msg.data32 = (port->loopback ? CCR_LOOPBACK : 0) |
414 		(port->id ? CCR_SECOND_HSS : 0);
415 	hss_npe_send(port, &msg, "HSS_SET_CORE_CR");
416 
417 	memset(&msg, 0, sizeof(msg));
418 	msg.cmd = PORT_CONFIG_WRITE;
419 	msg.hss_port = port->id;
420 	msg.index = HSS_CONFIG_CLOCK_CR;
421 	msg.data32 = port->clock_reg;
422 	hss_npe_send(port, &msg, "HSS_SET_CLOCK_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_TX_FCR;
428 	msg.data16a = FRAME_OFFSET;
429 	msg.data16b = FRAME_SIZE - 1;
430 	hss_npe_send(port, &msg, "HSS_SET_TX_FCR");
431 
432 	memset(&msg, 0, sizeof(msg));
433 	msg.cmd = PORT_CONFIG_WRITE;
434 	msg.hss_port = port->id;
435 	msg.index = HSS_CONFIG_RX_FCR;
436 	msg.data16a = FRAME_OFFSET;
437 	msg.data16b = FRAME_SIZE - 1;
438 	hss_npe_send(port, &msg, "HSS_SET_RX_FCR");
439 
440 	hss_config_set_lut(port);
441 
442 	memset(&msg, 0, sizeof(msg));
443 	msg.cmd = PORT_CONFIG_LOAD;
444 	msg.hss_port = port->id;
445 	hss_npe_send(port, &msg, "HSS_LOAD_CONFIG");
446 
447 	if (npe_recv_message(port->npe, &msg, "HSS_LOAD_CONFIG") ||
448 	    /* HSS_LOAD_CONFIG for port #1 returns port_id = #4 */
449 	    msg.cmd != PORT_CONFIG_LOAD || msg.data32) {
450 		pr_crit("HSS-%i: HSS_LOAD_CONFIG failed\n", port->id);
451 		BUG();
452 	}
453 
454 	/* HDLC may stop working without this - check FIXME */
455 	npe_recv_message(port->npe, &msg, "FLUSH_IT");
456 }
457 
458 static void hss_set_hdlc_cfg(struct port *port)
459 {
460 	struct msg msg;
461 
462 	memset(&msg, 0, sizeof(msg));
463 	msg.cmd = PKT_PIPE_HDLC_CFG_WRITE;
464 	msg.hss_port = port->id;
465 	msg.data8a = port->hdlc_cfg; /* rx_cfg */
466 	msg.data8b = port->hdlc_cfg | (PKT_EXTRA_FLAGS << 3); /* tx_cfg */
467 	hss_npe_send(port, &msg, "HSS_SET_HDLC_CFG");
468 }
469 
470 static u32 hss_get_status(struct port *port)
471 {
472 	struct msg msg;
473 
474 	memset(&msg, 0, sizeof(msg));
475 	msg.cmd = PORT_ERROR_READ;
476 	msg.hss_port = port->id;
477 	hss_npe_send(port, &msg, "PORT_ERROR_READ");
478 	if (npe_recv_message(port->npe, &msg, "PORT_ERROR_READ")) {
479 		pr_crit("HSS-%i: unable to read HSS status\n", port->id);
480 		BUG();
481 	}
482 
483 	return msg.data32;
484 }
485 
486 static void hss_start_hdlc(struct port *port)
487 {
488 	struct msg msg;
489 
490 	memset(&msg, 0, sizeof(msg));
491 	msg.cmd = PKT_PIPE_FLOW_ENABLE;
492 	msg.hss_port = port->id;
493 	msg.data32 = 0;
494 	hss_npe_send(port, &msg, "HSS_ENABLE_PKT_PIPE");
495 }
496 
497 static void hss_stop_hdlc(struct port *port)
498 {
499 	struct msg msg;
500 
501 	memset(&msg, 0, sizeof(msg));
502 	msg.cmd = PKT_PIPE_FLOW_DISABLE;
503 	msg.hss_port = port->id;
504 	hss_npe_send(port, &msg, "HSS_DISABLE_PKT_PIPE");
505 	hss_get_status(port); /* make sure it's halted */
506 }
507 
508 static int hss_load_firmware(struct port *port)
509 {
510 	struct msg msg;
511 	int err;
512 
513 	if (port->initialized)
514 		return 0;
515 
516 	if (!npe_running(port->npe) &&
517 	    (err = npe_load_firmware(port->npe, npe_name(port->npe),
518 				     port->dev)))
519 		return err;
520 
521 	/* HDLC mode configuration */
522 	memset(&msg, 0, sizeof(msg));
523 	msg.cmd = PKT_NUM_PIPES_WRITE;
524 	msg.hss_port = port->id;
525 	msg.data8a = PKT_NUM_PIPES;
526 	hss_npe_send(port, &msg, "HSS_SET_PKT_PIPES");
527 
528 	msg.cmd = PKT_PIPE_FIFO_SIZEW_WRITE;
529 	msg.data8a = PKT_PIPE_FIFO_SIZEW;
530 	hss_npe_send(port, &msg, "HSS_SET_PKT_FIFO");
531 
532 	msg.cmd = PKT_PIPE_MODE_WRITE;
533 	msg.data8a = NPE_PKT_MODE_HDLC;
534 	/* msg.data8b = inv_mask */
535 	/* msg.data8c = or_mask */
536 	hss_npe_send(port, &msg, "HSS_SET_PKT_MODE");
537 
538 	msg.cmd = PKT_PIPE_RX_SIZE_WRITE;
539 	msg.data16a = HDLC_MAX_MRU; /* including CRC */
540 	hss_npe_send(port, &msg, "HSS_SET_PKT_RX_SIZE");
541 
542 	msg.cmd = PKT_PIPE_IDLE_PATTERN_WRITE;
543 	msg.data32 = 0x7F7F7F7F; /* ??? FIXME */
544 	hss_npe_send(port, &msg, "HSS_SET_PKT_IDLE");
545 
546 	port->initialized = 1;
547 	return 0;
548 }
549 
550 /*****************************************************************************
551  * packetized (HDLC) operation
552  ****************************************************************************/
553 
554 static inline void debug_pkt(struct net_device *dev, const char *func,
555 			     u8 *data, int len)
556 {
557 #if DEBUG_PKT_BYTES
558 	int i;
559 
560 	printk(KERN_DEBUG "%s: %s(%i)", dev->name, func, len);
561 	for (i = 0; i < len; i++) {
562 		if (i >= DEBUG_PKT_BYTES)
563 			break;
564 		printk("%s%02X", !(i % 4) ? " " : "", data[i]);
565 	}
566 	printk("\n");
567 #endif
568 }
569 
570 
571 static inline void debug_desc(u32 phys, struct desc *desc)
572 {
573 #if DEBUG_DESC
574 	printk(KERN_DEBUG "%X: %X %3X %3X %08X %X %X\n",
575 	       phys, desc->next, desc->buf_len, desc->pkt_len,
576 	       desc->data, desc->status, desc->error_count);
577 #endif
578 }
579 
580 static inline int queue_get_desc(unsigned int queue, struct port *port,
581 				 int is_tx)
582 {
583 	u32 phys, tab_phys, n_desc;
584 	struct desc *tab;
585 
586 	if (!(phys = qmgr_get_entry(queue)))
587 		return -1;
588 
589 	BUG_ON(phys & 0x1F);
590 	tab_phys = is_tx ? tx_desc_phys(port, 0) : rx_desc_phys(port, 0);
591 	tab = is_tx ? tx_desc_ptr(port, 0) : rx_desc_ptr(port, 0);
592 	n_desc = (phys - tab_phys) / sizeof(struct desc);
593 	BUG_ON(n_desc >= (is_tx ? TX_DESCS : RX_DESCS));
594 	debug_desc(phys, &tab[n_desc]);
595 	BUG_ON(tab[n_desc].next);
596 	return n_desc;
597 }
598 
599 static inline void queue_put_desc(unsigned int queue, u32 phys,
600 				  struct desc *desc)
601 {
602 	debug_desc(phys, desc);
603 	BUG_ON(phys & 0x1F);
604 	qmgr_put_entry(queue, phys);
605 	/* Don't check for queue overflow here, we've allocated sufficient
606 	   length and queues >= 32 don't support this check anyway. */
607 }
608 
609 
610 static inline void dma_unmap_tx(struct port *port, struct desc *desc)
611 {
612 #ifdef __ARMEB__
613 	dma_unmap_single(&port->netdev->dev, desc->data,
614 			 desc->buf_len, DMA_TO_DEVICE);
615 #else
616 	dma_unmap_single(&port->netdev->dev, desc->data & ~3,
617 			 ALIGN((desc->data & 3) + desc->buf_len, 4),
618 			 DMA_TO_DEVICE);
619 #endif
620 }
621 
622 
623 static void hss_hdlc_set_carrier(void *pdev, int carrier)
624 {
625 	struct net_device *netdev = pdev;
626 	struct port *port = dev_to_port(netdev);
627 	unsigned long flags;
628 
629 	spin_lock_irqsave(&npe_lock, flags);
630 	port->carrier = carrier;
631 	if (!port->loopback) {
632 		if (carrier)
633 			netif_carrier_on(netdev);
634 		else
635 			netif_carrier_off(netdev);
636 	}
637 	spin_unlock_irqrestore(&npe_lock, flags);
638 }
639 
640 static void hss_hdlc_rx_irq(void *pdev)
641 {
642 	struct net_device *dev = pdev;
643 	struct port *port = dev_to_port(dev);
644 
645 #if DEBUG_RX
646 	printk(KERN_DEBUG "%s: hss_hdlc_rx_irq\n", dev->name);
647 #endif
648 	qmgr_disable_irq(queue_ids[port->id].rx);
649 	napi_schedule(&port->napi);
650 }
651 
652 static int hss_hdlc_poll(struct napi_struct *napi, int budget)
653 {
654 	struct port *port = container_of(napi, struct port, napi);
655 	struct net_device *dev = port->netdev;
656 	unsigned int rxq = queue_ids[port->id].rx;
657 	unsigned int rxfreeq = queue_ids[port->id].rxfree;
658 	int received = 0;
659 
660 #if DEBUG_RX
661 	printk(KERN_DEBUG "%s: hss_hdlc_poll\n", dev->name);
662 #endif
663 
664 	while (received < budget) {
665 		struct sk_buff *skb;
666 		struct desc *desc;
667 		int n;
668 #ifdef __ARMEB__
669 		struct sk_buff *temp;
670 		u32 phys;
671 #endif
672 
673 		if ((n = queue_get_desc(rxq, port, 0)) < 0) {
674 #if DEBUG_RX
675 			printk(KERN_DEBUG "%s: hss_hdlc_poll"
676 			       " napi_complete\n", dev->name);
677 #endif
678 			napi_complete(napi);
679 			qmgr_enable_irq(rxq);
680 			if (!qmgr_stat_empty(rxq) &&
681 			    napi_reschedule(napi)) {
682 #if DEBUG_RX
683 				printk(KERN_DEBUG "%s: hss_hdlc_poll"
684 				       " napi_reschedule succeeded\n",
685 				       dev->name);
686 #endif
687 				qmgr_disable_irq(rxq);
688 				continue;
689 			}
690 #if DEBUG_RX
691 			printk(KERN_DEBUG "%s: hss_hdlc_poll all done\n",
692 			       dev->name);
693 #endif
694 			return received; /* all work done */
695 		}
696 
697 		desc = rx_desc_ptr(port, n);
698 #if 0 /* FIXME - error_count counts modulo 256, perhaps we should use it */
699 		if (desc->error_count)
700 			printk(KERN_DEBUG "%s: hss_hdlc_poll status 0x%02X"
701 			       " errors %u\n", dev->name, desc->status,
702 			       desc->error_count);
703 #endif
704 		skb = NULL;
705 		switch (desc->status) {
706 		case 0:
707 #ifdef __ARMEB__
708 			if ((skb = netdev_alloc_skb(dev, RX_SIZE)) != NULL) {
709 				phys = dma_map_single(&dev->dev, skb->data,
710 						      RX_SIZE,
711 						      DMA_FROM_DEVICE);
712 				if (dma_mapping_error(&dev->dev, phys)) {
713 					dev_kfree_skb(skb);
714 					skb = NULL;
715 				}
716 			}
717 #else
718 			skb = netdev_alloc_skb(dev, desc->pkt_len);
719 #endif
720 			if (!skb)
721 				dev->stats.rx_dropped++;
722 			break;
723 		case ERR_HDLC_ALIGN:
724 		case ERR_HDLC_ABORT:
725 			dev->stats.rx_frame_errors++;
726 			dev->stats.rx_errors++;
727 			break;
728 		case ERR_HDLC_FCS:
729 			dev->stats.rx_crc_errors++;
730 			dev->stats.rx_errors++;
731 			break;
732 		case ERR_HDLC_TOO_LONG:
733 			dev->stats.rx_length_errors++;
734 			dev->stats.rx_errors++;
735 			break;
736 		default:	/* FIXME - remove printk */
737 			netdev_err(dev, "hss_hdlc_poll: status 0x%02X errors %u\n",
738 				   desc->status, desc->error_count);
739 			dev->stats.rx_errors++;
740 		}
741 
742 		if (!skb) {
743 			/* put the desc back on RX-ready queue */
744 			desc->buf_len = RX_SIZE;
745 			desc->pkt_len = desc->status = 0;
746 			queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
747 			continue;
748 		}
749 
750 		/* process received frame */
751 #ifdef __ARMEB__
752 		temp = skb;
753 		skb = port->rx_buff_tab[n];
754 		dma_unmap_single(&dev->dev, desc->data,
755 				 RX_SIZE, DMA_FROM_DEVICE);
756 #else
757 		dma_sync_single_for_cpu(&dev->dev, desc->data,
758 					RX_SIZE, DMA_FROM_DEVICE);
759 		memcpy_swab32((u32 *)skb->data, (u32 *)port->rx_buff_tab[n],
760 			      ALIGN(desc->pkt_len, 4) / 4);
761 #endif
762 		skb_put(skb, desc->pkt_len);
763 
764 		debug_pkt(dev, "hss_hdlc_poll", skb->data, skb->len);
765 
766 		skb->protocol = hdlc_type_trans(skb, dev);
767 		dev->stats.rx_packets++;
768 		dev->stats.rx_bytes += skb->len;
769 		netif_receive_skb(skb);
770 
771 		/* put the new buffer on RX-free queue */
772 #ifdef __ARMEB__
773 		port->rx_buff_tab[n] = temp;
774 		desc->data = phys;
775 #endif
776 		desc->buf_len = RX_SIZE;
777 		desc->pkt_len = 0;
778 		queue_put_desc(rxfreeq, rx_desc_phys(port, n), desc);
779 		received++;
780 	}
781 #if DEBUG_RX
782 	printk(KERN_DEBUG "hss_hdlc_poll: end, not all work done\n");
783 #endif
784 	return received;	/* not all work done */
785 }
786 
787 
788 static void hss_hdlc_txdone_irq(void *pdev)
789 {
790 	struct net_device *dev = pdev;
791 	struct port *port = dev_to_port(dev);
792 	int n_desc;
793 
794 #if DEBUG_TX
795 	printk(KERN_DEBUG DRV_NAME ": hss_hdlc_txdone_irq\n");
796 #endif
797 	while ((n_desc = queue_get_desc(queue_ids[port->id].txdone,
798 					port, 1)) >= 0) {
799 		struct desc *desc;
800 		int start;
801 
802 		desc = tx_desc_ptr(port, n_desc);
803 
804 		dev->stats.tx_packets++;
805 		dev->stats.tx_bytes += desc->pkt_len;
806 
807 		dma_unmap_tx(port, desc);
808 #if DEBUG_TX
809 		printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq free %p\n",
810 		       dev->name, port->tx_buff_tab[n_desc]);
811 #endif
812 		free_buffer_irq(port->tx_buff_tab[n_desc]);
813 		port->tx_buff_tab[n_desc] = NULL;
814 
815 		start = qmgr_stat_below_low_watermark(port->plat->txreadyq);
816 		queue_put_desc(port->plat->txreadyq,
817 			       tx_desc_phys(port, n_desc), desc);
818 		if (start) { /* TX-ready queue was empty */
819 #if DEBUG_TX
820 			printk(KERN_DEBUG "%s: hss_hdlc_txdone_irq xmit"
821 			       " ready\n", dev->name);
822 #endif
823 			netif_wake_queue(dev);
824 		}
825 	}
826 }
827 
828 static int hss_hdlc_xmit(struct sk_buff *skb, struct net_device *dev)
829 {
830 	struct port *port = dev_to_port(dev);
831 	unsigned int txreadyq = port->plat->txreadyq;
832 	int len, offset, bytes, n;
833 	void *mem;
834 	u32 phys;
835 	struct desc *desc;
836 
837 #if DEBUG_TX
838 	printk(KERN_DEBUG "%s: hss_hdlc_xmit\n", dev->name);
839 #endif
840 
841 	if (unlikely(skb->len > HDLC_MAX_MRU)) {
842 		dev_kfree_skb(skb);
843 		dev->stats.tx_errors++;
844 		return NETDEV_TX_OK;
845 	}
846 
847 	debug_pkt(dev, "hss_hdlc_xmit", skb->data, skb->len);
848 
849 	len = skb->len;
850 #ifdef __ARMEB__
851 	offset = 0; /* no need to keep alignment */
852 	bytes = len;
853 	mem = skb->data;
854 #else
855 	offset = (int)skb->data & 3; /* keep 32-bit alignment */
856 	bytes = ALIGN(offset + len, 4);
857 	if (!(mem = kmalloc(bytes, GFP_ATOMIC))) {
858 		dev_kfree_skb(skb);
859 		dev->stats.tx_dropped++;
860 		return NETDEV_TX_OK;
861 	}
862 	memcpy_swab32(mem, (u32 *)((uintptr_t)skb->data & ~3), bytes / 4);
863 	dev_kfree_skb(skb);
864 #endif
865 
866 	phys = dma_map_single(&dev->dev, mem, bytes, DMA_TO_DEVICE);
867 	if (dma_mapping_error(&dev->dev, phys)) {
868 #ifdef __ARMEB__
869 		dev_kfree_skb(skb);
870 #else
871 		kfree(mem);
872 #endif
873 		dev->stats.tx_dropped++;
874 		return NETDEV_TX_OK;
875 	}
876 
877 	n = queue_get_desc(txreadyq, port, 1);
878 	BUG_ON(n < 0);
879 	desc = tx_desc_ptr(port, n);
880 
881 #ifdef __ARMEB__
882 	port->tx_buff_tab[n] = skb;
883 #else
884 	port->tx_buff_tab[n] = mem;
885 #endif
886 	desc->data = phys + offset;
887 	desc->buf_len = desc->pkt_len = len;
888 
889 	wmb();
890 	queue_put_desc(queue_ids[port->id].tx, tx_desc_phys(port, n), desc);
891 
892 	if (qmgr_stat_below_low_watermark(txreadyq)) { /* empty */
893 #if DEBUG_TX
894 		printk(KERN_DEBUG "%s: hss_hdlc_xmit queue full\n", dev->name);
895 #endif
896 		netif_stop_queue(dev);
897 		/* we could miss TX ready interrupt */
898 		if (!qmgr_stat_below_low_watermark(txreadyq)) {
899 #if DEBUG_TX
900 			printk(KERN_DEBUG "%s: hss_hdlc_xmit ready again\n",
901 			       dev->name);
902 #endif
903 			netif_wake_queue(dev);
904 		}
905 	}
906 
907 #if DEBUG_TX
908 	printk(KERN_DEBUG "%s: hss_hdlc_xmit end\n", dev->name);
909 #endif
910 	return NETDEV_TX_OK;
911 }
912 
913 
914 static int request_hdlc_queues(struct port *port)
915 {
916 	int err;
917 
918 	err = qmgr_request_queue(queue_ids[port->id].rxfree, RX_DESCS, 0, 0,
919 				 "%s:RX-free", port->netdev->name);
920 	if (err)
921 		return err;
922 
923 	err = qmgr_request_queue(queue_ids[port->id].rx, RX_DESCS, 0, 0,
924 				 "%s:RX", port->netdev->name);
925 	if (err)
926 		goto rel_rxfree;
927 
928 	err = qmgr_request_queue(queue_ids[port->id].tx, TX_DESCS, 0, 0,
929 				 "%s:TX", port->netdev->name);
930 	if (err)
931 		goto rel_rx;
932 
933 	err = qmgr_request_queue(port->plat->txreadyq, TX_DESCS, 0, 0,
934 				 "%s:TX-ready", port->netdev->name);
935 	if (err)
936 		goto rel_tx;
937 
938 	err = qmgr_request_queue(queue_ids[port->id].txdone, TX_DESCS, 0, 0,
939 				 "%s:TX-done", port->netdev->name);
940 	if (err)
941 		goto rel_txready;
942 	return 0;
943 
944 rel_txready:
945 	qmgr_release_queue(port->plat->txreadyq);
946 rel_tx:
947 	qmgr_release_queue(queue_ids[port->id].tx);
948 rel_rx:
949 	qmgr_release_queue(queue_ids[port->id].rx);
950 rel_rxfree:
951 	qmgr_release_queue(queue_ids[port->id].rxfree);
952 	printk(KERN_DEBUG "%s: unable to request hardware queues\n",
953 	       port->netdev->name);
954 	return err;
955 }
956 
957 static void release_hdlc_queues(struct port *port)
958 {
959 	qmgr_release_queue(queue_ids[port->id].rxfree);
960 	qmgr_release_queue(queue_ids[port->id].rx);
961 	qmgr_release_queue(queue_ids[port->id].txdone);
962 	qmgr_release_queue(queue_ids[port->id].tx);
963 	qmgr_release_queue(port->plat->txreadyq);
964 }
965 
966 static int init_hdlc_queues(struct port *port)
967 {
968 	int i;
969 
970 	if (!ports_open) {
971 		dma_pool = dma_pool_create(DRV_NAME, &port->netdev->dev,
972 					   POOL_ALLOC_SIZE, 32, 0);
973 		if (!dma_pool)
974 			return -ENOMEM;
975 	}
976 
977 	if (!(port->desc_tab = dma_pool_alloc(dma_pool, GFP_KERNEL,
978 					      &port->desc_tab_phys)))
979 		return -ENOMEM;
980 	memset(port->desc_tab, 0, POOL_ALLOC_SIZE);
981 	memset(port->rx_buff_tab, 0, sizeof(port->rx_buff_tab)); /* tables */
982 	memset(port->tx_buff_tab, 0, sizeof(port->tx_buff_tab));
983 
984 	/* Setup RX buffers */
985 	for (i = 0; i < RX_DESCS; i++) {
986 		struct desc *desc = rx_desc_ptr(port, i);
987 		buffer_t *buff;
988 		void *data;
989 #ifdef __ARMEB__
990 		if (!(buff = netdev_alloc_skb(port->netdev, RX_SIZE)))
991 			return -ENOMEM;
992 		data = buff->data;
993 #else
994 		if (!(buff = kmalloc(RX_SIZE, GFP_KERNEL)))
995 			return -ENOMEM;
996 		data = buff;
997 #endif
998 		desc->buf_len = RX_SIZE;
999 		desc->data = dma_map_single(&port->netdev->dev, data,
1000 					    RX_SIZE, DMA_FROM_DEVICE);
1001 		if (dma_mapping_error(&port->netdev->dev, desc->data)) {
1002 			free_buffer(buff);
1003 			return -EIO;
1004 		}
1005 		port->rx_buff_tab[i] = buff;
1006 	}
1007 
1008 	return 0;
1009 }
1010 
1011 static void destroy_hdlc_queues(struct port *port)
1012 {
1013 	int i;
1014 
1015 	if (port->desc_tab) {
1016 		for (i = 0; i < RX_DESCS; i++) {
1017 			struct desc *desc = rx_desc_ptr(port, i);
1018 			buffer_t *buff = port->rx_buff_tab[i];
1019 			if (buff) {
1020 				dma_unmap_single(&port->netdev->dev,
1021 						 desc->data, RX_SIZE,
1022 						 DMA_FROM_DEVICE);
1023 				free_buffer(buff);
1024 			}
1025 		}
1026 		for (i = 0; i < TX_DESCS; i++) {
1027 			struct desc *desc = tx_desc_ptr(port, i);
1028 			buffer_t *buff = port->tx_buff_tab[i];
1029 			if (buff) {
1030 				dma_unmap_tx(port, desc);
1031 				free_buffer(buff);
1032 			}
1033 		}
1034 		dma_pool_free(dma_pool, port->desc_tab, port->desc_tab_phys);
1035 		port->desc_tab = NULL;
1036 	}
1037 
1038 	if (!ports_open && dma_pool) {
1039 		dma_pool_destroy(dma_pool);
1040 		dma_pool = NULL;
1041 	}
1042 }
1043 
1044 static int hss_hdlc_open(struct net_device *dev)
1045 {
1046 	struct port *port = dev_to_port(dev);
1047 	unsigned long flags;
1048 	int i, err = 0;
1049 
1050 	if ((err = hdlc_open(dev)))
1051 		return err;
1052 
1053 	if ((err = hss_load_firmware(port)))
1054 		goto err_hdlc_close;
1055 
1056 	if ((err = request_hdlc_queues(port)))
1057 		goto err_hdlc_close;
1058 
1059 	if ((err = init_hdlc_queues(port)))
1060 		goto err_destroy_queues;
1061 
1062 	spin_lock_irqsave(&npe_lock, flags);
1063 	if (port->plat->open)
1064 		if ((err = port->plat->open(port->id, dev,
1065 					    hss_hdlc_set_carrier)))
1066 			goto err_unlock;
1067 	spin_unlock_irqrestore(&npe_lock, flags);
1068 
1069 	/* Populate queues with buffers, no failure after this point */
1070 	for (i = 0; i < TX_DESCS; i++)
1071 		queue_put_desc(port->plat->txreadyq,
1072 			       tx_desc_phys(port, i), tx_desc_ptr(port, i));
1073 
1074 	for (i = 0; i < RX_DESCS; i++)
1075 		queue_put_desc(queue_ids[port->id].rxfree,
1076 			       rx_desc_phys(port, i), rx_desc_ptr(port, i));
1077 
1078 	napi_enable(&port->napi);
1079 	netif_start_queue(dev);
1080 
1081 	qmgr_set_irq(queue_ids[port->id].rx, QUEUE_IRQ_SRC_NOT_EMPTY,
1082 		     hss_hdlc_rx_irq, dev);
1083 
1084 	qmgr_set_irq(queue_ids[port->id].txdone, QUEUE_IRQ_SRC_NOT_EMPTY,
1085 		     hss_hdlc_txdone_irq, dev);
1086 	qmgr_enable_irq(queue_ids[port->id].txdone);
1087 
1088 	ports_open++;
1089 
1090 	hss_set_hdlc_cfg(port);
1091 	hss_config(port);
1092 
1093 	hss_start_hdlc(port);
1094 
1095 	/* we may already have RX data, enables IRQ */
1096 	napi_schedule(&port->napi);
1097 	return 0;
1098 
1099 err_unlock:
1100 	spin_unlock_irqrestore(&npe_lock, flags);
1101 err_destroy_queues:
1102 	destroy_hdlc_queues(port);
1103 	release_hdlc_queues(port);
1104 err_hdlc_close:
1105 	hdlc_close(dev);
1106 	return err;
1107 }
1108 
1109 static int hss_hdlc_close(struct net_device *dev)
1110 {
1111 	struct port *port = dev_to_port(dev);
1112 	unsigned long flags;
1113 	int i, buffs = RX_DESCS; /* allocated RX buffers */
1114 
1115 	spin_lock_irqsave(&npe_lock, flags);
1116 	ports_open--;
1117 	qmgr_disable_irq(queue_ids[port->id].rx);
1118 	netif_stop_queue(dev);
1119 	napi_disable(&port->napi);
1120 
1121 	hss_stop_hdlc(port);
1122 
1123 	while (queue_get_desc(queue_ids[port->id].rxfree, port, 0) >= 0)
1124 		buffs--;
1125 	while (queue_get_desc(queue_ids[port->id].rx, port, 0) >= 0)
1126 		buffs--;
1127 
1128 	if (buffs)
1129 		netdev_crit(dev, "unable to drain RX queue, %i buffer(s) left in NPE\n",
1130 			    buffs);
1131 
1132 	buffs = TX_DESCS;
1133 	while (queue_get_desc(queue_ids[port->id].tx, port, 1) >= 0)
1134 		buffs--; /* cancel TX */
1135 
1136 	i = 0;
1137 	do {
1138 		while (queue_get_desc(port->plat->txreadyq, port, 1) >= 0)
1139 			buffs--;
1140 		if (!buffs)
1141 			break;
1142 	} while (++i < MAX_CLOSE_WAIT);
1143 
1144 	if (buffs)
1145 		netdev_crit(dev, "unable to drain TX queue, %i buffer(s) left in NPE\n",
1146 			    buffs);
1147 #if DEBUG_CLOSE
1148 	if (!buffs)
1149 		printk(KERN_DEBUG "Draining TX queues took %i cycles\n", i);
1150 #endif
1151 	qmgr_disable_irq(queue_ids[port->id].txdone);
1152 
1153 	if (port->plat->close)
1154 		port->plat->close(port->id, dev);
1155 	spin_unlock_irqrestore(&npe_lock, flags);
1156 
1157 	destroy_hdlc_queues(port);
1158 	release_hdlc_queues(port);
1159 	hdlc_close(dev);
1160 	return 0;
1161 }
1162 
1163 
1164 static int hss_hdlc_attach(struct net_device *dev, unsigned short encoding,
1165 			   unsigned short parity)
1166 {
1167 	struct port *port = dev_to_port(dev);
1168 
1169 	if (encoding != ENCODING_NRZ)
1170 		return -EINVAL;
1171 
1172 	switch(parity) {
1173 	case PARITY_CRC16_PR1_CCITT:
1174 		port->hdlc_cfg = 0;
1175 		return 0;
1176 
1177 	case PARITY_CRC32_PR1_CCITT:
1178 		port->hdlc_cfg = PKT_HDLC_CRC_32;
1179 		return 0;
1180 
1181 	default:
1182 		return -EINVAL;
1183 	}
1184 }
1185 
1186 static u32 check_clock(u32 timer_freq, u32 rate, u32 a, u32 b, u32 c,
1187 		       u32 *best, u32 *best_diff, u32 *reg)
1188 {
1189 	/* a is 10-bit, b is 10-bit, c is 12-bit */
1190 	u64 new_rate;
1191 	u32 new_diff;
1192 
1193 	new_rate = timer_freq * (u64)(c + 1);
1194 	do_div(new_rate, a * (c + 1) + b + 1);
1195 	new_diff = abs((u32)new_rate - rate);
1196 
1197 	if (new_diff < *best_diff) {
1198 		*best = new_rate;
1199 		*best_diff = new_diff;
1200 		*reg = (a << 22) | (b << 12) | c;
1201 	}
1202 	return new_diff;
1203 }
1204 
1205 static void find_best_clock(u32 timer_freq, u32 rate, u32 *best, u32 *reg)
1206 {
1207 	u32 a, b, diff = 0xFFFFFFFF;
1208 
1209 	a = timer_freq / rate;
1210 
1211 	if (a > 0x3FF) { /* 10-bit value - we can go as slow as ca. 65 kb/s */
1212 		check_clock(timer_freq, rate, 0x3FF, 1, 1, best, &diff, reg);
1213 		return;
1214 	}
1215 	if (a == 0) { /* > 66.666 MHz */
1216 		a = 1; /* minimum divider is 1 (a = 0, b = 1, c = 1) */
1217 		rate = timer_freq;
1218 	}
1219 
1220 	if (rate * a == timer_freq) { /* don't divide by 0 later */
1221 		check_clock(timer_freq, rate, a - 1, 1, 1, best, &diff, reg);
1222 		return;
1223 	}
1224 
1225 	for (b = 0; b < 0x400; b++) {
1226 		u64 c = (b + 1) * (u64)rate;
1227 		do_div(c, timer_freq - rate * a);
1228 		c--;
1229 		if (c >= 0xFFF) { /* 12-bit - no need to check more 'b's */
1230 			if (b == 0 && /* also try a bit higher rate */
1231 			    !check_clock(timer_freq, rate, a - 1, 1, 1, best,
1232 					 &diff, reg))
1233 				return;
1234 			check_clock(timer_freq, rate, a, b, 0xFFF, best,
1235 				    &diff, reg);
1236 			return;
1237 		}
1238 		if (!check_clock(timer_freq, rate, a, b, c, best, &diff, reg))
1239 			return;
1240 		if (!check_clock(timer_freq, rate, a, b, c + 1, best, &diff,
1241 				 reg))
1242 			return;
1243 	}
1244 }
1245 
1246 static int hss_hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1247 {
1248 	const size_t size = sizeof(sync_serial_settings);
1249 	sync_serial_settings new_line;
1250 	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
1251 	struct port *port = dev_to_port(dev);
1252 	unsigned long flags;
1253 	int clk;
1254 
1255 	if (cmd != SIOCWANDEV)
1256 		return hdlc_ioctl(dev, ifr, cmd);
1257 
1258 	switch(ifr->ifr_settings.type) {
1259 	case IF_GET_IFACE:
1260 		ifr->ifr_settings.type = IF_IFACE_V35;
1261 		if (ifr->ifr_settings.size < size) {
1262 			ifr->ifr_settings.size = size; /* data size wanted */
1263 			return -ENOBUFS;
1264 		}
1265 		memset(&new_line, 0, sizeof(new_line));
1266 		new_line.clock_type = port->clock_type;
1267 		new_line.clock_rate = port->clock_rate;
1268 		new_line.loopback = port->loopback;
1269 		if (copy_to_user(line, &new_line, size))
1270 			return -EFAULT;
1271 		return 0;
1272 
1273 	case IF_IFACE_SYNC_SERIAL:
1274 	case IF_IFACE_V35:
1275 		if(!capable(CAP_NET_ADMIN))
1276 			return -EPERM;
1277 		if (copy_from_user(&new_line, line, size))
1278 			return -EFAULT;
1279 
1280 		clk = new_line.clock_type;
1281 		if (port->plat->set_clock)
1282 			clk = port->plat->set_clock(port->id, clk);
1283 
1284 		if (clk != CLOCK_EXT && clk != CLOCK_INT)
1285 			return -EINVAL;	/* No such clock setting */
1286 
1287 		if (new_line.loopback != 0 && new_line.loopback != 1)
1288 			return -EINVAL;
1289 
1290 		port->clock_type = clk; /* Update settings */
1291 		if (clk == CLOCK_INT)
1292 			find_best_clock(port->plat->timer_freq,
1293 					new_line.clock_rate,
1294 					&port->clock_rate, &port->clock_reg);
1295 		else {
1296 			port->clock_rate = 0;
1297 			port->clock_reg = CLK42X_SPEED_2048KHZ;
1298 		}
1299 		port->loopback = new_line.loopback;
1300 
1301 		spin_lock_irqsave(&npe_lock, flags);
1302 
1303 		if (dev->flags & IFF_UP)
1304 			hss_config(port);
1305 
1306 		if (port->loopback || port->carrier)
1307 			netif_carrier_on(port->netdev);
1308 		else
1309 			netif_carrier_off(port->netdev);
1310 		spin_unlock_irqrestore(&npe_lock, flags);
1311 
1312 		return 0;
1313 
1314 	default:
1315 		return hdlc_ioctl(dev, ifr, cmd);
1316 	}
1317 }
1318 
1319 /*****************************************************************************
1320  * initialization
1321  ****************************************************************************/
1322 
1323 static const struct net_device_ops hss_hdlc_ops = {
1324 	.ndo_open       = hss_hdlc_open,
1325 	.ndo_stop       = hss_hdlc_close,
1326 	.ndo_start_xmit = hdlc_start_xmit,
1327 	.ndo_do_ioctl   = hss_hdlc_ioctl,
1328 };
1329 
1330 static int hss_init_one(struct platform_device *pdev)
1331 {
1332 	struct port *port;
1333 	struct net_device *dev;
1334 	hdlc_device *hdlc;
1335 	int err;
1336 
1337 	if ((port = kzalloc(sizeof(*port), GFP_KERNEL)) == NULL)
1338 		return -ENOMEM;
1339 
1340 	if ((port->npe = npe_request(0)) == NULL) {
1341 		err = -ENODEV;
1342 		goto err_free;
1343 	}
1344 
1345 	if ((port->netdev = dev = alloc_hdlcdev(port)) == NULL) {
1346 		err = -ENOMEM;
1347 		goto err_plat;
1348 	}
1349 
1350 	SET_NETDEV_DEV(dev, &pdev->dev);
1351 	hdlc = dev_to_hdlc(dev);
1352 	hdlc->attach = hss_hdlc_attach;
1353 	hdlc->xmit = hss_hdlc_xmit;
1354 	dev->netdev_ops = &hss_hdlc_ops;
1355 	dev->tx_queue_len = 100;
1356 	port->clock_type = CLOCK_EXT;
1357 	port->clock_rate = 0;
1358 	port->clock_reg = CLK42X_SPEED_2048KHZ;
1359 	port->id = pdev->id;
1360 	port->dev = &pdev->dev;
1361 	port->plat = pdev->dev.platform_data;
1362 	netif_napi_add(dev, &port->napi, hss_hdlc_poll, NAPI_WEIGHT);
1363 
1364 	if ((err = register_hdlc_device(dev)))
1365 		goto err_free_netdev;
1366 
1367 	platform_set_drvdata(pdev, port);
1368 
1369 	netdev_info(dev, "initialized\n");
1370 	return 0;
1371 
1372 err_free_netdev:
1373 	free_netdev(dev);
1374 err_plat:
1375 	npe_release(port->npe);
1376 err_free:
1377 	kfree(port);
1378 	return err;
1379 }
1380 
1381 static int hss_remove_one(struct platform_device *pdev)
1382 {
1383 	struct port *port = platform_get_drvdata(pdev);
1384 
1385 	unregister_hdlc_device(port->netdev);
1386 	free_netdev(port->netdev);
1387 	npe_release(port->npe);
1388 	kfree(port);
1389 	return 0;
1390 }
1391 
1392 static struct platform_driver ixp4xx_hss_driver = {
1393 	.driver.name	= DRV_NAME,
1394 	.probe		= hss_init_one,
1395 	.remove		= hss_remove_one,
1396 };
1397 
1398 static int __init hss_init_module(void)
1399 {
1400 	if ((ixp4xx_read_feature_bits() &
1401 	     (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS)) !=
1402 	    (IXP4XX_FEATURE_HDLC | IXP4XX_FEATURE_HSS))
1403 		return -ENODEV;
1404 
1405 	spin_lock_init(&npe_lock);
1406 
1407 	return platform_driver_register(&ixp4xx_hss_driver);
1408 }
1409 
1410 static void __exit hss_cleanup_module(void)
1411 {
1412 	platform_driver_unregister(&ixp4xx_hss_driver);
1413 }
1414 
1415 MODULE_AUTHOR("Krzysztof Halasa");
1416 MODULE_DESCRIPTION("Intel IXP4xx HSS driver");
1417 MODULE_LICENSE("GPL v2");
1418 MODULE_ALIAS("platform:ixp4xx_hss");
1419 module_init(hss_init_module);
1420 module_exit(hss_cleanup_module);
1421