]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - drivers/i2c/busses/i2c-mv64xxx.c
projects / mirror_ubuntu-zesty-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge remote-tracking branches 'regulator/topic/lp8788', 'regulator/topic/mt6311...
[mirror_ubuntu-zesty-kernel.git] / drivers / i2c / busses / i2c-mv64xxx.c
1 /*
2 * Driver for the i2c controller on the Marvell line of host bridges
3 * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family).
4 *
5 * Author: Mark A. Greer <mgreer@mvista.com>
6 *
7 * 2005 (c) MontaVista, Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
10 * or implied.
11 */
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/module.h>
15 #include <linux/spinlock.h>
16 #include <linux/i2c.h>
17 #include <linux/interrupt.h>
18 #include <linux/mv643xx_i2c.h>
19 #include <linux/platform_device.h>
20 #include <linux/reset.h>
21 #include <linux/io.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include <linux/of_irq.h>
25 #include <linux/clk.h>
26 #include <linux/err.h>
27 #include <linux/delay.h>
28
29 #define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1)
30 #define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7)
31 #define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3)
32
33 #define MV64XXX_I2C_REG_CONTROL_ACK BIT(2)
34 #define MV64XXX_I2C_REG_CONTROL_IFLG BIT(3)
35 #define MV64XXX_I2C_REG_CONTROL_STOP BIT(4)
36 #define MV64XXX_I2C_REG_CONTROL_START BIT(5)
37 #define MV64XXX_I2C_REG_CONTROL_TWSIEN BIT(6)
38 #define MV64XXX_I2C_REG_CONTROL_INTEN BIT(7)
39
40 /* Ctlr status values */
41 #define MV64XXX_I2C_STATUS_BUS_ERR 0x00
42 #define MV64XXX_I2C_STATUS_MAST_START 0x08
43 #define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
44 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
45 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
46 #define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
47 #define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
48 #define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
49 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
50 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
51 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
52 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
53 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
54 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
55 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
56 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
57 #define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
58
59 /* Register defines (I2C bridge) */
60 #define MV64XXX_I2C_REG_TX_DATA_LO 0xc0
61 #define MV64XXX_I2C_REG_TX_DATA_HI 0xc4
62 #define MV64XXX_I2C_REG_RX_DATA_LO 0xc8
63 #define MV64XXX_I2C_REG_RX_DATA_HI 0xcc
64 #define MV64XXX_I2C_REG_BRIDGE_CONTROL 0xd0
65 #define MV64XXX_I2C_REG_BRIDGE_STATUS 0xd4
66 #define MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE 0xd8
67 #define MV64XXX_I2C_REG_BRIDGE_INTR_MASK 0xdC
68 #define MV64XXX_I2C_REG_BRIDGE_TIMING 0xe0
69
70 /* Bridge Control values */
71 #define MV64XXX_I2C_BRIDGE_CONTROL_WR BIT(0)
72 #define MV64XXX_I2C_BRIDGE_CONTROL_RD BIT(1)
73 #define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT 2
74 #define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT BIT(12)
75 #define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT 13
76 #define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT 16
77 #define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE BIT(19)
78 #define MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START BIT(20)
79
80 /* Bridge Status values */
81 #define MV64XXX_I2C_BRIDGE_STATUS_ERROR BIT(0)
82
83 /* Driver states */
84 enum {
85 MV64XXX_I2C_STATE_INVALID,
86 MV64XXX_I2C_STATE_IDLE,
87 MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
88 MV64XXX_I2C_STATE_WAITING_FOR_RESTART,
89 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
90 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
91 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
92 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
93 };
94
95 /* Driver actions */
96 enum {
97 MV64XXX_I2C_ACTION_INVALID,
98 MV64XXX_I2C_ACTION_CONTINUE,
99 MV64XXX_I2C_ACTION_SEND_RESTART,
100 MV64XXX_I2C_ACTION_SEND_ADDR_1,
101 MV64XXX_I2C_ACTION_SEND_ADDR_2,
102 MV64XXX_I2C_ACTION_SEND_DATA,
103 MV64XXX_I2C_ACTION_RCV_DATA,
104 MV64XXX_I2C_ACTION_RCV_DATA_STOP,
105 MV64XXX_I2C_ACTION_SEND_STOP,
106 };
107
108 struct mv64xxx_i2c_regs {
109 u8 addr;
110 u8 ext_addr;
111 u8 data;
112 u8 control;
113 u8 status;
114 u8 clock;
115 u8 soft_reset;
116 };
117
118 struct mv64xxx_i2c_data {
119 struct i2c_msg *msgs;
120 int num_msgs;
121 int irq;
122 u32 state;
123 u32 action;
124 u32 aborting;
125 u32 cntl_bits;
126 void __iomem *reg_base;
127 struct mv64xxx_i2c_regs reg_offsets;
128 u32 addr1;
129 u32 addr2;
130 u32 bytes_left;
131 u32 byte_posn;
132 u32 send_stop;
133 u32 block;
134 int rc;
135 u32 freq_m;
136 u32 freq_n;
137 #if defined(CONFIG_HAVE_CLK)
138 struct clk *clk;
139 #endif
140 wait_queue_head_t waitq;
141 spinlock_t lock;
142 struct i2c_msg *msg;
143 struct i2c_adapter adapter;
144 bool offload_enabled;
145 /* 5us delay in order to avoid repeated start timing violation */
146 bool errata_delay;
147 struct reset_control *rstc;
148 bool irq_clear_inverted;
149 /* Clk div is 2 to the power n, not 2 to the power n + 1 */
150 bool clk_n_base_0;
151 };
152
153 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = {
154 .addr = 0x00,
155 .ext_addr = 0x10,
156 .data = 0x04,
157 .control = 0x08,
158 .status = 0x0c,
159 .clock = 0x0c,
160 .soft_reset = 0x1c,
161 };
162
163 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = {
164 .addr = 0x00,
165 .ext_addr = 0x04,
166 .data = 0x08,
167 .control = 0x0c,
168 .status = 0x10,
169 .clock = 0x14,
170 .soft_reset = 0x18,
171 };
172
173 static void
174 mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
175 struct i2c_msg *msg)
176 {
177 u32 dir = 0;
178
179 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
180 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
181
182 if (msg->flags & I2C_M_RD)
183 dir = 1;
184
185 if (msg->flags & I2C_M_TEN) {
186 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
187 drv_data->addr2 = (u32)msg->addr & 0xff;
188 } else {
189 drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir;
190 drv_data->addr2 = 0;
191 }
192 }
193
194 /*
195 *****************************************************************************
196 *
197 * Finite State Machine & Interrupt Routines
198 *
199 *****************************************************************************
200 */
201
202 /* Reset hardware and initialize FSM */
203 static void
204 mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
205 {
206 if (drv_data->offload_enabled) {
207 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
208 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_TIMING);
209 writel(0, drv_data->reg_base +
210 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
211 writel(0, drv_data->reg_base +
212 MV64XXX_I2C_REG_BRIDGE_INTR_MASK);
213 }
214
215 writel(0, drv_data->reg_base + drv_data->reg_offsets.soft_reset);
216 writel(MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n),
217 drv_data->reg_base + drv_data->reg_offsets.clock);
218 writel(0, drv_data->reg_base + drv_data->reg_offsets.addr);
219 writel(0, drv_data->reg_base + drv_data->reg_offsets.ext_addr);
220 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
221 drv_data->reg_base + drv_data->reg_offsets.control);
222 drv_data->state = MV64XXX_I2C_STATE_IDLE;
223 }
224
225 static void
226 mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
227 {
228 /*
229 * If state is idle, then this is likely the remnants of an old
230 * operation that driver has given up on or the user has killed.
231 * If so, issue the stop condition and go to idle.
232 */
233 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
234 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
235 return;
236 }
237
238 /* The status from the ctlr [mostly] tells us what to do next */
239 switch (status) {
240 /* Start condition interrupt */
241 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
242 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
243 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
244 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
245 break;
246
247 /* Performing a write */
248 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
249 if (drv_data->msg->flags & I2C_M_TEN) {
250 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
251 drv_data->state =
252 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
253 break;
254 }
255 /* FALLTHRU */
256 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
257 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
258 if ((drv_data->bytes_left == 0)
259 || (drv_data->aborting
260 && (drv_data->byte_posn != 0))) {
261 if (drv_data->send_stop || drv_data->aborting) {
262 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
263 drv_data->state = MV64XXX_I2C_STATE_IDLE;
264 } else {
265 drv_data->action =
266 MV64XXX_I2C_ACTION_SEND_RESTART;
267 drv_data->state =
268 MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
269 }
270 } else {
271 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
272 drv_data->state =
273 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
274 drv_data->bytes_left--;
275 }
276 break;
277
278 /* Performing a read */
279 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
280 if (drv_data->msg->flags & I2C_M_TEN) {
281 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
282 drv_data->state =
283 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
284 break;
285 }
286 /* FALLTHRU */
287 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
288 if (drv_data->bytes_left == 0) {
289 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
290 drv_data->state = MV64XXX_I2C_STATE_IDLE;
291 break;
292 }
293 /* FALLTHRU */
294 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
295 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
296 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
297 else {
298 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
299 drv_data->bytes_left--;
300 }
301 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
302
303 if ((drv_data->bytes_left == 1) || drv_data->aborting)
304 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
305 break;
306
307 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
308 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
309 drv_data->state = MV64XXX_I2C_STATE_IDLE;
310 break;
311
312 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
313 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
314 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
315 /* Doesn't seem to be a device at other end */
316 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
317 drv_data->state = MV64XXX_I2C_STATE_IDLE;
318 drv_data->rc = -ENXIO;
319 break;
320
321 default:
322 dev_err(&drv_data->adapter.dev,
323 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
324 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
325 drv_data->state, status, drv_data->msg->addr,
326 drv_data->msg->flags);
327 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
328 mv64xxx_i2c_hw_init(drv_data);
329 drv_data->rc = -EIO;
330 }
331 }
332
333 static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data)
334 {
335 drv_data->msg = drv_data->msgs;
336 drv_data->byte_posn = 0;
337 drv_data->bytes_left = drv_data->msg->len;
338 drv_data->aborting = 0;
339 drv_data->rc = 0;
340
341 mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
342 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
343 drv_data->reg_base + drv_data->reg_offsets.control);
344 }
345
346 static void
347 mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
348 {
349 switch(drv_data->action) {
350 case MV64XXX_I2C_ACTION_SEND_RESTART:
351 /* We should only get here if we have further messages */
352 BUG_ON(drv_data->num_msgs == 0);
353
354 drv_data->msgs++;
355 drv_data->num_msgs--;
356 mv64xxx_i2c_send_start(drv_data);
357
358 if (drv_data->errata_delay)
359 udelay(5);
360
361 /*
362 * We're never at the start of the message here, and by this
363 * time it's already too late to do any protocol mangling.
364 * Thankfully, do not advertise support for that feature.
365 */
366 drv_data->send_stop = drv_data->num_msgs == 1;
367 break;
368
369 case MV64XXX_I2C_ACTION_CONTINUE:
370 writel(drv_data->cntl_bits,
371 drv_data->reg_base + drv_data->reg_offsets.control);
372 break;
373
374 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
375 writel(drv_data->addr1,
376 drv_data->reg_base + drv_data->reg_offsets.data);
377 writel(drv_data->cntl_bits,
378 drv_data->reg_base + drv_data->reg_offsets.control);
379 break;
380
381 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
382 writel(drv_data->addr2,
383 drv_data->reg_base + drv_data->reg_offsets.data);
384 writel(drv_data->cntl_bits,
385 drv_data->reg_base + drv_data->reg_offsets.control);
386 break;
387
388 case MV64XXX_I2C_ACTION_SEND_DATA:
389 writel(drv_data->msg->buf[drv_data->byte_posn++],
390 drv_data->reg_base + drv_data->reg_offsets.data);
391 writel(drv_data->cntl_bits,
392 drv_data->reg_base + drv_data->reg_offsets.control);
393 break;
394
395 case MV64XXX_I2C_ACTION_RCV_DATA:
396 drv_data->msg->buf[drv_data->byte_posn++] =
397 readl(drv_data->reg_base + drv_data->reg_offsets.data);
398 writel(drv_data->cntl_bits,
399 drv_data->reg_base + drv_data->reg_offsets.control);
400 break;
401
402 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
403 drv_data->msg->buf[drv_data->byte_posn++] =
404 readl(drv_data->reg_base + drv_data->reg_offsets.data);
405 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
406 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
407 drv_data->reg_base + drv_data->reg_offsets.control);
408 drv_data->block = 0;
409 if (drv_data->errata_delay)
410 udelay(5);
411
412 wake_up(&drv_data->waitq);
413 break;
414
415 case MV64XXX_I2C_ACTION_INVALID:
416 default:
417 dev_err(&drv_data->adapter.dev,
418 "mv64xxx_i2c_do_action: Invalid action: %d\n",
419 drv_data->action);
420 drv_data->rc = -EIO;
421
422 /* FALLTHRU */
423 case MV64XXX_I2C_ACTION_SEND_STOP:
424 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
425 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
426 drv_data->reg_base + drv_data->reg_offsets.control);
427 drv_data->block = 0;
428 wake_up(&drv_data->waitq);
429 break;
430 }
431 }
432
433 static void
434 mv64xxx_i2c_read_offload_rx_data(struct mv64xxx_i2c_data *drv_data,
435 struct i2c_msg *msg)
436 {
437 u32 buf[2];
438
439 buf[0] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_LO);
440 buf[1] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_HI);
441
442 memcpy(msg->buf, buf, msg->len);
443 }
444
445 static int
446 mv64xxx_i2c_intr_offload(struct mv64xxx_i2c_data *drv_data)
447 {
448 u32 cause, status;
449
450 cause = readl(drv_data->reg_base +
451 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
452 if (!cause)
453 return IRQ_NONE;
454
455 status = readl(drv_data->reg_base +
456 MV64XXX_I2C_REG_BRIDGE_STATUS);
457
458 if (status & MV64XXX_I2C_BRIDGE_STATUS_ERROR) {
459 drv_data->rc = -EIO;
460 goto out;
461 }
462
463 drv_data->rc = 0;
464
465 /*
466 * Transaction is a one message read transaction, read data
467 * for this message.
468 */
469 if (drv_data->num_msgs == 1 && drv_data->msgs[0].flags & I2C_M_RD) {
470 mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs);
471 drv_data->msgs++;
472 drv_data->num_msgs--;
473 }
474 /*
475 * Transaction is a two messages write/read transaction, read
476 * data for the second (read) message.
477 */
478 else if (drv_data->num_msgs == 2 &&
479 !(drv_data->msgs[0].flags & I2C_M_RD) &&
480 drv_data->msgs[1].flags & I2C_M_RD) {
481 mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs + 1);
482 drv_data->msgs += 2;
483 drv_data->num_msgs -= 2;
484 }
485
486 out:
487 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
488 writel(0, drv_data->reg_base +
489 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
490 drv_data->block = 0;
491
492 wake_up(&drv_data->waitq);
493
494 return IRQ_HANDLED;
495 }
496
497 static irqreturn_t
498 mv64xxx_i2c_intr(int irq, void *dev_id)
499 {
500 struct mv64xxx_i2c_data *drv_data = dev_id;
501 unsigned long flags;
502 u32 status;
503 irqreturn_t rc = IRQ_NONE;
504
505 spin_lock_irqsave(&drv_data->lock, flags);
506
507 if (drv_data->offload_enabled)
508 rc = mv64xxx_i2c_intr_offload(drv_data);
509
510 while (readl(drv_data->reg_base + drv_data->reg_offsets.control) &
511 MV64XXX_I2C_REG_CONTROL_IFLG) {
512 status = readl(drv_data->reg_base + drv_data->reg_offsets.status);
513 mv64xxx_i2c_fsm(drv_data, status);
514 mv64xxx_i2c_do_action(drv_data);
515
516 if (drv_data->irq_clear_inverted)
517 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_IFLG,
518 drv_data->reg_base + drv_data->reg_offsets.control);
519
520 rc = IRQ_HANDLED;
521 }
522 spin_unlock_irqrestore(&drv_data->lock, flags);
523
524 return rc;
525 }
526
527 /*
528 *****************************************************************************
529 *
530 * I2C Msg Execution Routines
531 *
532 *****************************************************************************
533 */
534 static void
535 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
536 {
537 long time_left;
538 unsigned long flags;
539 char abort = 0;
540
541 time_left = wait_event_timeout(drv_data->waitq,
542 !drv_data->block, drv_data->adapter.timeout);
543
544 spin_lock_irqsave(&drv_data->lock, flags);
545 if (!time_left) { /* Timed out */
546 drv_data->rc = -ETIMEDOUT;
547 abort = 1;
548 } else if (time_left < 0) { /* Interrupted/Error */
549 drv_data->rc = time_left; /* errno value */
550 abort = 1;
551 }
552
553 if (abort && drv_data->block) {
554 drv_data->aborting = 1;
555 spin_unlock_irqrestore(&drv_data->lock, flags);
556
557 time_left = wait_event_timeout(drv_data->waitq,
558 !drv_data->block, drv_data->adapter.timeout);
559
560 if ((time_left <= 0) && drv_data->block) {
561 drv_data->state = MV64XXX_I2C_STATE_IDLE;
562 dev_err(&drv_data->adapter.dev,
563 "mv64xxx: I2C bus locked, block: %d, "
564 "time_left: %d\n", drv_data->block,
565 (int)time_left);
566 mv64xxx_i2c_hw_init(drv_data);
567 }
568 } else
569 spin_unlock_irqrestore(&drv_data->lock, flags);
570 }
571
572 static int
573 mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
574 int is_last)
575 {
576 unsigned long flags;
577
578 spin_lock_irqsave(&drv_data->lock, flags);
579
580 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
581
582 drv_data->send_stop = is_last;
583 drv_data->block = 1;
584 mv64xxx_i2c_send_start(drv_data);
585 spin_unlock_irqrestore(&drv_data->lock, flags);
586
587 mv64xxx_i2c_wait_for_completion(drv_data);
588 return drv_data->rc;
589 }
590
591 static void
592 mv64xxx_i2c_prepare_tx(struct mv64xxx_i2c_data *drv_data)
593 {
594 struct i2c_msg *msg = drv_data->msgs;
595 u32 buf[2];
596
597 memcpy(buf, msg->buf, msg->len);
598
599 writel(buf[0], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO);
600 writel(buf[1], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI);
601 }
602
603 static int
604 mv64xxx_i2c_offload_xfer(struct mv64xxx_i2c_data *drv_data)
605 {
606 struct i2c_msg *msgs = drv_data->msgs;
607 int num = drv_data->num_msgs;
608 unsigned long ctrl_reg;
609 unsigned long flags;
610
611 spin_lock_irqsave(&drv_data->lock, flags);
612
613 /* Build transaction */
614 ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE |
615 (msgs[0].addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT);
616
617 if (msgs[0].flags & I2C_M_TEN)
618 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT;
619
620 /* Single write message transaction */
621 if (num == 1 && !(msgs[0].flags & I2C_M_RD)) {
622 size_t len = msgs[0].len - 1;
623
624 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR |
625 (len << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT);
626 mv64xxx_i2c_prepare_tx(drv_data);
627 }
628 /* Single read message transaction */
629 else if (num == 1 && msgs[0].flags & I2C_M_RD) {
630 size_t len = msgs[0].len - 1;
631
632 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD |
633 (len << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT);
634 }
635 /*
636 * Transaction with one write and one read message. This is
637 * guaranteed by the mv64xx_i2c_can_offload() checks.
638 */
639 else if (num == 2) {
640 size_t lentx = msgs[0].len - 1;
641 size_t lenrx = msgs[1].len - 1;
642
643 ctrl_reg |=
644 MV64XXX_I2C_BRIDGE_CONTROL_RD |
645 MV64XXX_I2C_BRIDGE_CONTROL_WR |
646 (lentx << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT) |
647 (lenrx << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT) |
648 MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START;
649 mv64xxx_i2c_prepare_tx(drv_data);
650 }
651
652 /* Execute transaction */
653 drv_data->block = 1;
654 writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
655 spin_unlock_irqrestore(&drv_data->lock, flags);
656
657 mv64xxx_i2c_wait_for_completion(drv_data);
658
659 return drv_data->rc;
660 }
661
662 static bool
663 mv64xxx_i2c_valid_offload_sz(struct i2c_msg *msg)
664 {
665 return msg->len <= 8 && msg->len >= 1;
666 }
667
668 static bool
669 mv64xxx_i2c_can_offload(struct mv64xxx_i2c_data *drv_data)
670 {
671 struct i2c_msg *msgs = drv_data->msgs;
672 int num = drv_data->num_msgs;
673
674 if (!drv_data->offload_enabled)
675 return false;
676
677 /*
678 * We can offload a transaction consisting of a single
679 * message, as long as the message has a length between 1 and
680 * 8 bytes.
681 */
682 if (num == 1 && mv64xxx_i2c_valid_offload_sz(msgs))
683 return true;
684
685 /*
686 * We can offload a transaction consisting of two messages, if
687 * the first is a write and a second is a read, and both have
688 * a length between 1 and 8 bytes.
689 */
690 if (num == 2 &&
691 mv64xxx_i2c_valid_offload_sz(msgs) &&
692 mv64xxx_i2c_valid_offload_sz(msgs + 1) &&
693 !(msgs[0].flags & I2C_M_RD) &&
694 msgs[1].flags & I2C_M_RD)
695 return true;
696
697 return false;
698 }
699
700 /*
701 *****************************************************************************
702 *
703 * I2C Core Support Routines (Interface to higher level I2C code)
704 *
705 *****************************************************************************
706 */
707 static u32
708 mv64xxx_i2c_functionality(struct i2c_adapter *adap)
709 {
710 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
711 }
712
713 static int
714 mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
715 {
716 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
717 int rc, ret = num;
718
719 BUG_ON(drv_data->msgs != NULL);
720 drv_data->msgs = msgs;
721 drv_data->num_msgs = num;
722
723 if (mv64xxx_i2c_can_offload(drv_data))
724 rc = mv64xxx_i2c_offload_xfer(drv_data);
725 else
726 rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1);
727
728 if (rc < 0)
729 ret = rc;
730
731 drv_data->num_msgs = 0;
732 drv_data->msgs = NULL;
733
734 return ret;
735 }
736
737 static const struct i2c_algorithm mv64xxx_i2c_algo = {
738 .master_xfer = mv64xxx_i2c_xfer,
739 .functionality = mv64xxx_i2c_functionality,
740 };
741
742 /*
743 *****************************************************************************
744 *
745 * Driver Interface & Early Init Routines
746 *
747 *****************************************************************************
748 */
749 static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
750 { .compatible = "allwinner,sun4i-a10-i2c", .data = &mv64xxx_i2c_regs_sun4i},
751 { .compatible = "allwinner,sun6i-a31-i2c", .data = &mv64xxx_i2c_regs_sun4i},
752 { .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
753 { .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
754 { .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
755 {}
756 };
757 MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
758
759 #ifdef CONFIG_OF
760 #ifdef CONFIG_HAVE_CLK
761 static int
762 mv64xxx_calc_freq(struct mv64xxx_i2c_data *drv_data,
763 const int tclk, const int n, const int m)
764 {
765 if (drv_data->clk_n_base_0)
766 return tclk / (10 * (m + 1) * (1 << n));
767 else
768 return tclk / (10 * (m + 1) * (2 << n));
769 }
770
771 static bool
772 mv64xxx_find_baud_factors(struct mv64xxx_i2c_data *drv_data,
773 const u32 req_freq, const u32 tclk)
774 {
775 int freq, delta, best_delta = INT_MAX;
776 int m, n;
777
778 for (n = 0; n <= 7; n++)
779 for (m = 0; m <= 15; m++) {
780 freq = mv64xxx_calc_freq(drv_data, tclk, n, m);
781 delta = req_freq - freq;
782 if (delta >= 0 && delta < best_delta) {
783 drv_data->freq_m = m;
784 drv_data->freq_n = n;
785 best_delta = delta;
786 }
787 if (best_delta == 0)
788 return true;
789 }
790 if (best_delta == INT_MAX)
791 return false;
792 return true;
793 }
794 #endif /* CONFIG_HAVE_CLK */
795
796 static int
797 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
798 struct device *dev)
799 {
800 /* CLK is mandatory when using DT to describe the i2c bus. We
801 * need to know tclk in order to calculate bus clock
802 * factors.
803 */
804 #if !defined(CONFIG_HAVE_CLK)
805 /* Have OF but no CLK */
806 return -ENODEV;
807 #else
808 const struct of_device_id *device;
809 struct device_node *np = dev->of_node;
810 u32 bus_freq, tclk;
811 int rc = 0;
812
813 if (IS_ERR(drv_data->clk)) {
814 rc = -ENODEV;
815 goto out;
816 }
817 tclk = clk_get_rate(drv_data->clk);
818
819 if (of_property_read_u32(np, "clock-frequency", &bus_freq))
820 bus_freq = 100000; /* 100kHz by default */
821
822 if (of_device_is_compatible(np, "allwinner,sun4i-a10-i2c") ||
823 of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
824 drv_data->clk_n_base_0 = true;
825
826 if (!mv64xxx_find_baud_factors(drv_data, bus_freq, tclk)) {
827 rc = -EINVAL;
828 goto out;
829 }
830 drv_data->irq = irq_of_parse_and_map(np, 0);
831
832 drv_data->rstc = devm_reset_control_get_optional(dev, NULL);
833 if (IS_ERR(drv_data->rstc)) {
834 if (PTR_ERR(drv_data->rstc) == -EPROBE_DEFER) {
835 rc = -EPROBE_DEFER;
836 goto out;
837 }
838 } else {
839 reset_control_deassert(drv_data->rstc);
840 }
841
842 /* Its not yet defined how timeouts will be specified in device tree.
843 * So hard code the value to 1 second.
844 */
845 drv_data->adapter.timeout = HZ;
846
847 device = of_match_device(mv64xxx_i2c_of_match_table, dev);
848 if (!device)
849 return -ENODEV;
850
851 memcpy(&drv_data->reg_offsets, device->data, sizeof(drv_data->reg_offsets));
852
853 /*
854 * For controllers embedded in new SoCs activate the
855 * Transaction Generator support and the errata fix.
856 */
857 if (of_device_is_compatible(np, "marvell,mv78230-i2c")) {
858 drv_data->offload_enabled = true;
859 drv_data->errata_delay = true;
860 }
861
862 if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) {
863 drv_data->offload_enabled = false;
864 drv_data->errata_delay = true;
865 }
866
867 if (of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
868 drv_data->irq_clear_inverted = true;
869
870 out:
871 return rc;
872 #endif
873 }
874 #else /* CONFIG_OF */
875 static int
876 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
877 struct device *dev)
878 {
879 return -ENODEV;
880 }
881 #endif /* CONFIG_OF */
882
883 static int
884 mv64xxx_i2c_probe(struct platform_device *pd)
885 {
886 struct mv64xxx_i2c_data *drv_data;
887 struct mv64xxx_i2c_pdata *pdata = dev_get_platdata(&pd->dev);
888 struct resource *r;
889 int rc;
890
891 if ((!pdata && !pd->dev.of_node))
892 return -ENODEV;
893
894 drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data),
895 GFP_KERNEL);
896 if (!drv_data)
897 return -ENOMEM;
898
899 r = platform_get_resource(pd, IORESOURCE_MEM, 0);
900 drv_data->reg_base = devm_ioremap_resource(&pd->dev, r);
901 if (IS_ERR(drv_data->reg_base))
902 return PTR_ERR(drv_data->reg_base);
903
904 strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
905 sizeof(drv_data->adapter.name));
906
907 init_waitqueue_head(&drv_data->waitq);
908 spin_lock_init(&drv_data->lock);
909
910 #if defined(CONFIG_HAVE_CLK)
911 /* Not all platforms have a clk */
912 drv_data->clk = devm_clk_get(&pd->dev, NULL);
913 if (!IS_ERR(drv_data->clk)) {
914 clk_prepare(drv_data->clk);
915 clk_enable(drv_data->clk);
916 }
917 #endif
918 if (pdata) {
919 drv_data->freq_m = pdata->freq_m;
920 drv_data->freq_n = pdata->freq_n;
921 drv_data->irq = platform_get_irq(pd, 0);
922 drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
923 drv_data->offload_enabled = false;
924 memcpy(&drv_data->reg_offsets, &mv64xxx_i2c_regs_mv64xxx, sizeof(drv_data->reg_offsets));
925 } else if (pd->dev.of_node) {
926 rc = mv64xxx_of_config(drv_data, &pd->dev);
927 if (rc)
928 goto exit_clk;
929 }
930 if (drv_data->irq < 0) {
931 rc = -ENXIO;
932 goto exit_reset;
933 }
934
935 drv_data->adapter.dev.parent = &pd->dev;
936 drv_data->adapter.algo = &mv64xxx_i2c_algo;
937 drv_data->adapter.owner = THIS_MODULE;
938 drv_data->adapter.class = I2C_CLASS_DEPRECATED;
939 drv_data->adapter.nr = pd->id;
940 drv_data->adapter.dev.of_node = pd->dev.of_node;
941 platform_set_drvdata(pd, drv_data);
942 i2c_set_adapdata(&drv_data->adapter, drv_data);
943
944 mv64xxx_i2c_hw_init(drv_data);
945
946 rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
947 MV64XXX_I2C_CTLR_NAME, drv_data);
948 if (rc) {
949 dev_err(&drv_data->adapter.dev,
950 "mv64xxx: Can't register intr handler irq%d: %d\n",
951 drv_data->irq, rc);
952 goto exit_reset;
953 } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
954 dev_err(&drv_data->adapter.dev,
955 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
956 goto exit_free_irq;
957 }
958
959 return 0;
960
961 exit_free_irq:
962 free_irq(drv_data->irq, drv_data);
963 exit_reset:
964 if (!IS_ERR_OR_NULL(drv_data->rstc))
965 reset_control_assert(drv_data->rstc);
966 exit_clk:
967 #if defined(CONFIG_HAVE_CLK)
968 /* Not all platforms have a clk */
969 if (!IS_ERR(drv_data->clk)) {
970 clk_disable(drv_data->clk);
971 clk_unprepare(drv_data->clk);
972 }
973 #endif
974 return rc;
975 }
976
977 static int
978 mv64xxx_i2c_remove(struct platform_device *dev)
979 {
980 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
981
982 i2c_del_adapter(&drv_data->adapter);
983 free_irq(drv_data->irq, drv_data);
984 if (!IS_ERR_OR_NULL(drv_data->rstc))
985 reset_control_assert(drv_data->rstc);
986 #if defined(CONFIG_HAVE_CLK)
987 /* Not all platforms have a clk */
988 if (!IS_ERR(drv_data->clk)) {
989 clk_disable(drv_data->clk);
990 clk_unprepare(drv_data->clk);
991 }
992 #endif
993
994 return 0;
995 }
996
997 static struct platform_driver mv64xxx_i2c_driver = {
998 .probe = mv64xxx_i2c_probe,
999 .remove = mv64xxx_i2c_remove,
1000 .driver = {
1001 .name = MV64XXX_I2C_CTLR_NAME,
1002 .of_match_table = mv64xxx_i2c_of_match_table,
1003 },
1004 };
1005
1006 module_platform_driver(mv64xxx_i2c_driver);
1007
1008 MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
1009 MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
1010 MODULE_LICENSE("GPL");
ubuntu-zesty-kernel mirror