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1 /*
2  * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
3  * Copyright (c) 2010-2011 NVIDIA Corporation
4  *  NVIDIA Corporation <www.nvidia.com>
5  *
6  * SPDX-License-Identifier:     GPL-2.0+
7  */
8
9 #include <common.h>
10 #include <fdtdec.h>
11 #include <i2c.h>
12 #include <asm/io.h>
13 #include <asm/arch/clock.h>
14 #include <asm/arch/funcmux.h>
15 #include <asm/arch/gpio.h>
16 #include <asm/arch/pinmux.h>
17 #include <asm/arch-tegra/clk_rst.h>
18 #include <asm/arch-tegra/tegra_i2c.h>
19
20 DECLARE_GLOBAL_DATA_PTR;
21
22 /* Information about i2c controller */
23 struct i2c_bus {
24         int                     id;
25         enum periph_id          periph_id;
26         int                     speed;
27         int                     pinmux_config;
28         struct i2c_control      *control;
29         struct i2c_ctlr         *regs;
30         int                     is_dvc; /* DVC type, rather than I2C */
31         int                     is_scs; /* single clock source (T114+) */
32         int                     inited; /* bus is inited */
33 };
34
35 static struct i2c_bus i2c_controllers[TEGRA_I2C_NUM_CONTROLLERS];
36
37 static void set_packet_mode(struct i2c_bus *i2c_bus)
38 {
39         u32 config;
40
41         config = I2C_CNFG_NEW_MASTER_FSM_MASK | I2C_CNFG_PACKET_MODE_MASK;
42
43         if (i2c_bus->is_dvc) {
44                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
45
46                 writel(config, &dvc->cnfg);
47         } else {
48                 writel(config, &i2c_bus->regs->cnfg);
49                 /*
50                  * program I2C_SL_CNFG.NEWSL to ENABLE. This fixes probe
51                  * issues, i.e., some slaves may be wrongly detected.
52                  */
53                 setbits_le32(&i2c_bus->regs->sl_cnfg, I2C_SL_CNFG_NEWSL_MASK);
54         }
55 }
56
57 static void i2c_reset_controller(struct i2c_bus *i2c_bus)
58 {
59         /* Reset I2C controller. */
60         reset_periph(i2c_bus->periph_id, 1);
61
62         /* re-program config register to packet mode */
63         set_packet_mode(i2c_bus);
64 }
65
66 static void i2c_init_controller(struct i2c_bus *i2c_bus)
67 {
68         /*
69          * Use PLLP - DP-04508-001_v06 datasheet indicates a divisor of 8
70          * here, in section 23.3.1, but in fact we seem to need a factor of
71          * 16 to get the right frequency.
72          */
73         clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
74                 i2c_bus->speed * 2 * 8);
75
76         if (i2c_bus->is_scs) {
77                 /*
78                  * T114 I2C went to a single clock source for standard/fast and
79                  * HS clock speeds. The new clock rate setting calculation is:
80                  *  SCL = CLK_SOURCE.I2C /
81                  *   (CLK_MULT_STD_FAST_MODE * (I2C_CLK_DIV_STD_FAST_MODE+1) *
82                  *   I2C FREQUENCY DIVISOR) as per the T114 TRM (sec 30.3.1).
83                  *
84                  * NOTE: We do this here, after the initial clock/pll start,
85                  * because if we read the clk_div reg before the controller
86                  * is running, we hang, and we need it for the new calc.
87                  */
88                 int clk_div_stdfst_mode = readl(&i2c_bus->regs->clk_div) >> 16;
89                 debug("%s: CLK_DIV_STD_FAST_MODE setting = %d\n", __func__,
90                         clk_div_stdfst_mode);
91
92                 clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
93                         CLK_MULT_STD_FAST_MODE * (clk_div_stdfst_mode + 1) *
94                         i2c_bus->speed * 2);
95         }
96
97         /* Reset I2C controller. */
98         i2c_reset_controller(i2c_bus);
99
100         /* Configure I2C controller. */
101         if (i2c_bus->is_dvc) {  /* only for DVC I2C */
102                 struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
103
104                 setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK);
105         }
106
107         funcmux_select(i2c_bus->periph_id, i2c_bus->pinmux_config);
108 }
109
110 static void send_packet_headers(
111         struct i2c_bus *i2c_bus,
112         struct i2c_trans_info *trans,
113         u32 packet_id,
114         bool end_with_repeated_start)
115 {
116         u32 data;
117
118         /* prepare header1: Header size = 0 Protocol = I2C, pktType = 0 */
119         data = PROTOCOL_TYPE_I2C << PKT_HDR1_PROTOCOL_SHIFT;
120         data |= packet_id << PKT_HDR1_PKT_ID_SHIFT;
121         data |= i2c_bus->id << PKT_HDR1_CTLR_ID_SHIFT;
122         writel(data, &i2c_bus->control->tx_fifo);
123         debug("pkt header 1 sent (0x%x)\n", data);
124
125         /* prepare header2 */
126         data = (trans->num_bytes - 1) << PKT_HDR2_PAYLOAD_SIZE_SHIFT;
127         writel(data, &i2c_bus->control->tx_fifo);
128         debug("pkt header 2 sent (0x%x)\n", data);
129
130         /* prepare IO specific header: configure the slave address */
131         data = trans->address << PKT_HDR3_SLAVE_ADDR_SHIFT;
132
133         /* Enable Read if it is not a write transaction */
134         if (!(trans->flags & I2C_IS_WRITE))
135                 data |= PKT_HDR3_READ_MODE_MASK;
136         if (end_with_repeated_start)
137                 data |= PKT_HDR3_REPEAT_START_MASK;
138
139         /* Write I2C specific header */
140         writel(data, &i2c_bus->control->tx_fifo);
141         debug("pkt header 3 sent (0x%x)\n", data);
142 }
143
144 static int wait_for_tx_fifo_empty(struct i2c_control *control)
145 {
146         u32 count;
147         int timeout_us = I2C_TIMEOUT_USEC;
148
149         while (timeout_us >= 0) {
150                 count = (readl(&control->fifo_status) & TX_FIFO_EMPTY_CNT_MASK)
151                                 >> TX_FIFO_EMPTY_CNT_SHIFT;
152                 if (count == I2C_FIFO_DEPTH)
153                         return 1;
154                 udelay(10);
155                 timeout_us -= 10;
156         }
157
158         return 0;
159 }
160
161 static int wait_for_rx_fifo_notempty(struct i2c_control *control)
162 {
163         u32 count;
164         int timeout_us = I2C_TIMEOUT_USEC;
165
166         while (timeout_us >= 0) {
167                 count = (readl(&control->fifo_status) & TX_FIFO_FULL_CNT_MASK)
168                                 >> TX_FIFO_FULL_CNT_SHIFT;
169                 if (count)
170                         return 1;
171                 udelay(10);
172                 timeout_us -= 10;
173         }
174
175         return 0;
176 }
177
178 static int wait_for_transfer_complete(struct i2c_control *control)
179 {
180         int int_status;
181         int timeout_us = I2C_TIMEOUT_USEC;
182
183         while (timeout_us >= 0) {
184                 int_status = readl(&control->int_status);
185                 if (int_status & I2C_INT_NO_ACK_MASK)
186                         return -int_status;
187                 if (int_status & I2C_INT_ARBITRATION_LOST_MASK)
188                         return -int_status;
189                 if (int_status & I2C_INT_XFER_COMPLETE_MASK)
190                         return 0;
191
192                 udelay(10);
193                 timeout_us -= 10;
194         }
195
196         return -1;
197 }
198
199 static int send_recv_packets(struct i2c_bus *i2c_bus,
200                              struct i2c_trans_info *trans)
201 {
202         struct i2c_control *control = i2c_bus->control;
203         u32 int_status;
204         u32 words;
205         u8 *dptr;
206         u32 local;
207         uchar last_bytes;
208         int error = 0;
209         int is_write = trans->flags & I2C_IS_WRITE;
210
211         /* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */
212         int_status = readl(&control->int_status);
213         writel(int_status, &control->int_status);
214
215         send_packet_headers(i2c_bus, trans, 1,
216                             trans->flags & I2C_USE_REPEATED_START);
217
218         words = DIV_ROUND_UP(trans->num_bytes, 4);
219         last_bytes = trans->num_bytes & 3;
220         dptr = trans->buf;
221
222         while (words) {
223                 u32 *wptr = (u32 *)dptr;
224
225                 if (is_write) {
226                         /* deal with word alignment */
227                         if ((words == 1) && last_bytes) {
228                                 local = 0;
229                                 memcpy(&local, dptr, last_bytes);
230                         } else if ((unsigned)dptr & 3) {
231                                 memcpy(&local, dptr, sizeof(u32));
232                         } else {
233                                 local = *wptr;
234                         }
235                         writel(local, &control->tx_fifo);
236                         debug("pkt data sent (0x%x)\n", local);
237                         if (!wait_for_tx_fifo_empty(control)) {
238                                 error = -1;
239                                 goto exit;
240                         }
241                 } else {
242                         if (!wait_for_rx_fifo_notempty(control)) {
243                                 error = -1;
244                                 goto exit;
245                         }
246                         /*
247                          * for the last word, we read into our local buffer,
248                          * in case that caller did not provide enough buffer.
249                          */
250                         local = readl(&control->rx_fifo);
251                         if ((words == 1) && last_bytes)
252                                 memcpy(dptr, (char *)&local, last_bytes);
253                         else if ((unsigned)dptr & 3)
254                                 memcpy(dptr, &local, sizeof(u32));
255                         else
256                                 *wptr = local;
257                         debug("pkt data received (0x%x)\n", local);
258                 }
259                 words--;
260                 dptr += sizeof(u32);
261         }
262
263         if (wait_for_transfer_complete(control)) {
264                 error = -1;
265                 goto exit;
266         }
267         return 0;
268 exit:
269         /* error, reset the controller. */
270         i2c_reset_controller(i2c_bus);
271
272         return error;
273 }
274
275 static int tegra_i2c_write_data(struct i2c_bus *bus, u32 addr, u8 *data,
276                                 u32 len, bool end_with_repeated_start)
277 {
278         int error;
279         struct i2c_trans_info trans_info;
280
281         trans_info.address = addr;
282         trans_info.buf = data;
283         trans_info.flags = I2C_IS_WRITE;
284         if (end_with_repeated_start)
285                 trans_info.flags |= I2C_USE_REPEATED_START;
286         trans_info.num_bytes = len;
287         trans_info.is_10bit_address = 0;
288
289         error = send_recv_packets(bus, &trans_info);
290         if (error)
291                 debug("tegra_i2c_write_data: Error (%d) !!!\n", error);
292
293         return error;
294 }
295
296 static int tegra_i2c_read_data(struct i2c_bus *bus, u32 addr, u8 *data,
297                                u32 len)
298 {
299         int error;
300         struct i2c_trans_info trans_info;
301
302         trans_info.address = addr | 1;
303         trans_info.buf = data;
304         trans_info.flags = 0;
305         trans_info.num_bytes = len;
306         trans_info.is_10bit_address = 0;
307
308         error = send_recv_packets(bus, &trans_info);
309         if (error)
310                 debug("tegra_i2c_read_data: Error (%d) !!!\n", error);
311
312         return error;
313 }
314
315 #ifndef CONFIG_OF_CONTROL
316 #error "Please enable device tree support to use this driver"
317 #endif
318
319 /**
320  * Check that a bus number is valid and return a pointer to it
321  *
322  * @param bus_num       Bus number to check / return
323  * @return pointer to bus, if valid, else NULL
324  */
325 static struct i2c_bus *tegra_i2c_get_bus(struct i2c_adapter *adap)
326 {
327         struct i2c_bus *bus;
328
329         bus = &i2c_controllers[adap->hwadapnr];
330         if (!bus->inited) {
331                 debug("%s: Bus %u not available\n", __func__, adap->hwadapnr);
332                 return NULL;
333         }
334
335         return bus;
336 }
337
338 static unsigned int tegra_i2c_set_bus_speed(struct i2c_adapter *adap,
339                         unsigned int speed)
340 {
341         struct i2c_bus *bus;
342
343         bus = tegra_i2c_get_bus(adap);
344         if (!bus)
345                 return 0;
346         bus->speed = speed;
347         i2c_init_controller(bus);
348
349         return 0;
350 }
351
352 static int i2c_get_config(const void *blob, int node, struct i2c_bus *i2c_bus)
353 {
354         i2c_bus->regs = (struct i2c_ctlr *)fdtdec_get_addr(blob, node, "reg");
355
356         /*
357          * We don't have a binding for pinmux yet. Leave it out for now. So
358          * far no one needs anything other than the default.
359          */
360         i2c_bus->pinmux_config = FUNCMUX_DEFAULT;
361         i2c_bus->speed = fdtdec_get_int(blob, node, "clock-frequency", 0);
362         i2c_bus->periph_id = clock_decode_periph_id(blob, node);
363
364         /*
365          * We can't specify the pinmux config in the fdt, so I2C2 will not
366          * work on Seaboard. It normally has no devices on it anyway.
367          * You could add in this little hack if you need to use it.
368          * The correct solution is a pinmux binding in the fdt.
369          *
370          *      if (i2c_bus->periph_id == PERIPH_ID_I2C2)
371          *              i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA;
372          */
373         if (i2c_bus->periph_id == -1)
374                 return -FDT_ERR_NOTFOUND;
375
376         return 0;
377 }
378
379 /*
380  * Process a list of nodes, adding them to our list of I2C ports.
381  *
382  * @param blob          fdt blob
383  * @param node_list     list of nodes to process (any <=0 are ignored)
384  * @param count         number of nodes to process
385  * @param is_dvc        1 if these are DVC ports, 0 if standard I2C
386  * @param is_scs        1 if this HW uses a single clock source (T114+)
387  * @return 0 if ok, -1 on error
388  */
389 static int process_nodes(const void *blob, int node_list[], int count,
390                          int is_dvc, int is_scs)
391 {
392         struct i2c_bus *i2c_bus;
393         int i;
394
395         /* build the i2c_controllers[] for each controller */
396         for (i = 0; i < count; i++) {
397                 int node = node_list[i];
398
399                 if (node <= 0)
400                         continue;
401
402                 i2c_bus = &i2c_controllers[i];
403                 i2c_bus->id = i;
404
405                 if (i2c_get_config(blob, node, i2c_bus)) {
406                         printf("i2c_init_board: failed to decode bus %d\n", i);
407                         return -1;
408                 }
409
410                 i2c_bus->is_scs = is_scs;
411
412                 i2c_bus->is_dvc = is_dvc;
413                 if (is_dvc) {
414                         i2c_bus->control =
415                                 &((struct dvc_ctlr *)i2c_bus->regs)->control;
416                 } else {
417                         i2c_bus->control = &i2c_bus->regs->control;
418                 }
419                 debug("%s: controller bus %d at %p, periph_id %d, speed %d: ",
420                       is_dvc ? "dvc" : "i2c", i, i2c_bus->regs,
421                       i2c_bus->periph_id, i2c_bus->speed);
422                 i2c_init_controller(i2c_bus);
423                 debug("ok\n");
424                 i2c_bus->inited = 1;
425
426                 /* Mark position as used */
427                 node_list[i] = -1;
428         }
429
430         return 0;
431 }
432
433 /* Sadly there is no error return from this function */
434 void i2c_init_board(void)
435 {
436         int node_list[TEGRA_I2C_NUM_CONTROLLERS];
437         const void *blob = gd->fdt_blob;
438         int count;
439
440         /* First check for newer (T114+) I2C ports */
441         count = fdtdec_find_aliases_for_id(blob, "i2c",
442                         COMPAT_NVIDIA_TEGRA114_I2C, node_list,
443                         TEGRA_I2C_NUM_CONTROLLERS);
444         if (process_nodes(blob, node_list, count, 0, 1))
445                 return;
446
447         /* Now get the older (T20/T30) normal I2C ports */
448         count = fdtdec_find_aliases_for_id(blob, "i2c",
449                         COMPAT_NVIDIA_TEGRA20_I2C, node_list,
450                         TEGRA_I2C_NUM_CONTROLLERS);
451         if (process_nodes(blob, node_list, count, 0, 0))
452                 return;
453
454         /* Now look for dvc ports */
455         count = fdtdec_add_aliases_for_id(blob, "i2c",
456                         COMPAT_NVIDIA_TEGRA20_DVC, node_list,
457                         TEGRA_I2C_NUM_CONTROLLERS);
458         if (process_nodes(blob, node_list, count, 1, 0))
459                 return;
460 }
461
462 static void tegra_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
463 {
464         /* No i2c support prior to relocation */
465         if (!(gd->flags & GD_FLG_RELOC))
466                 return;
467
468         /* This will override the speed selected in the fdt for that port */
469         debug("i2c_init(speed=%u, slaveaddr=0x%x)\n", speed, slaveaddr);
470         i2c_set_bus_speed(speed);
471 }
472
473 /* i2c write version without the register address */
474 static int i2c_write_data(struct i2c_bus *bus, uchar chip, uchar *buffer,
475                           int len, bool end_with_repeated_start)
476 {
477         int rc;
478
479         debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
480         debug("write_data: ");
481         /* use rc for counter */
482         for (rc = 0; rc < len; ++rc)
483                 debug(" 0x%02x", buffer[rc]);
484         debug("\n");
485
486         /* Shift 7-bit address over for lower-level i2c functions */
487         rc = tegra_i2c_write_data(bus, chip << 1, buffer, len,
488                                   end_with_repeated_start);
489         if (rc)
490                 debug("i2c_write_data(): rc=%d\n", rc);
491
492         return rc;
493 }
494
495 /* i2c read version without the register address */
496 static int i2c_read_data(struct i2c_bus *bus, uchar chip, uchar *buffer,
497                                 int len)
498 {
499         int rc;
500
501         debug("inside i2c_read_data():\n");
502         /* Shift 7-bit address over for lower-level i2c functions */
503         rc = tegra_i2c_read_data(bus, chip << 1, buffer, len);
504         if (rc) {
505                 debug("i2c_read_data(): rc=%d\n", rc);
506                 return rc;
507         }
508
509         debug("i2c_read_data: ");
510         /* reuse rc for counter*/
511         for (rc = 0; rc < len; ++rc)
512                 debug(" 0x%02x", buffer[rc]);
513         debug("\n");
514
515         return 0;
516 }
517
518 /* Probe to see if a chip is present. */
519 static int tegra_i2c_probe(struct i2c_adapter *adap, uchar chip)
520 {
521         struct i2c_bus *bus;
522         int rc;
523         uchar reg;
524
525         debug("i2c_probe: addr=0x%x\n", chip);
526         bus = tegra_i2c_get_bus(adap);
527         if (!bus)
528                 return 1;
529         reg = 0;
530         rc = i2c_write_data(bus, chip, &reg, 1, false);
531         if (rc) {
532                 debug("Error probing 0x%x.\n", chip);
533                 return 1;
534         }
535         return 0;
536 }
537
538 static int i2c_addr_ok(const uint addr, const int alen)
539 {
540         /* We support 7 or 10 bit addresses, so one or two bytes each */
541         return alen == 1 || alen == 2;
542 }
543
544 /* Read bytes */
545 static int tegra_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
546                         int alen, uchar *buffer, int len)
547 {
548         struct i2c_bus *bus;
549         uint offset;
550         int i;
551
552         debug("i2c_read: chip=0x%x, addr=0x%x, alen=0x%x len=0x%x\n",
553               chip, addr, alen, len);
554         bus = tegra_i2c_get_bus(adap);
555         if (!bus)
556                 return 1;
557         if (!i2c_addr_ok(addr, alen)) {
558                 debug("i2c_read: Bad address %x.%d.\n", addr, alen);
559                 return 1;
560         }
561         for (offset = 0; offset < len; offset++) {
562                 if (alen) {
563                         uchar data[alen];
564                         for (i = 0; i < alen; i++) {
565                                 data[alen - i - 1] =
566                                         (addr + offset) >> (8 * i);
567                         }
568                         if (i2c_write_data(bus, chip, data, alen, true)) {
569                                 debug("i2c_read: error sending (0x%x)\n",
570                                         addr);
571                                 return 1;
572                         }
573                 }
574                 if (i2c_read_data(bus, chip, buffer + offset, 1)) {
575                         debug("i2c_read: error reading (0x%x)\n", addr);
576                         return 1;
577                 }
578         }
579
580         return 0;
581 }
582
583 /* Write bytes */
584 static int tegra_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
585                         int alen, uchar *buffer, int len)
586 {
587         struct i2c_bus *bus;
588         uint offset;
589         int i;
590
591         debug("i2c_write: chip=0x%x, addr=0x%x, alen=0x%x len=0x%x\n",
592               chip, addr, alen, len);
593         bus = tegra_i2c_get_bus(adap);
594         if (!bus)
595                 return 1;
596         if (!i2c_addr_ok(addr, alen)) {
597                 debug("i2c_write: Bad address %x.%d.\n", addr, alen);
598                 return 1;
599         }
600         for (offset = 0; offset < len; offset++) {
601                 uchar data[alen + 1];
602                 for (i = 0; i < alen; i++)
603                         data[alen - i - 1] = (addr + offset) >> (8 * i);
604                 data[alen] = buffer[offset];
605                 if (i2c_write_data(bus, chip, data, alen + 1, false)) {
606                         debug("i2c_write: error sending (0x%x)\n", addr);
607                         return 1;
608                 }
609         }
610
611         return 0;
612 }
613
614 int tegra_i2c_get_dvc_bus_num(void)
615 {
616         int i;
617
618         for (i = 0; i < TEGRA_I2C_NUM_CONTROLLERS; i++) {
619                 struct i2c_bus *bus = &i2c_controllers[i];
620
621                 if (bus->inited && bus->is_dvc)
622                         return i;
623         }
624
625         return -1;
626 }
627
628 /*
629  * Register soft i2c adapters
630  */
631 U_BOOT_I2C_ADAP_COMPLETE(tegra0, tegra_i2c_init, tegra_i2c_probe,
632                          tegra_i2c_read, tegra_i2c_write,
633                          tegra_i2c_set_bus_speed, 100000, 0, 0)
634 U_BOOT_I2C_ADAP_COMPLETE(tegra1, tegra_i2c_init, tegra_i2c_probe,
635                          tegra_i2c_read, tegra_i2c_write,
636                          tegra_i2c_set_bus_speed, 100000, 0, 1)
637 U_BOOT_I2C_ADAP_COMPLETE(tegra2, tegra_i2c_init, tegra_i2c_probe,
638                          tegra_i2c_read, tegra_i2c_write,
639                          tegra_i2c_set_bus_speed, 100000, 0, 2)
640 U_BOOT_I2C_ADAP_COMPLETE(tegra3, tegra_i2c_init, tegra_i2c_probe,
641                          tegra_i2c_read, tegra_i2c_write,
642                          tegra_i2c_set_bus_speed, 100000, 0, 3)
643 #if TEGRA_I2C_NUM_CONTROLLERS > 4
644 U_BOOT_I2C_ADAP_COMPLETE(tegra4, tegra_i2c_init, tegra_i2c_probe,
645                          tegra_i2c_read, tegra_i2c_write,
646                          tegra_i2c_set_bus_speed, 100000, 0, 4)
647 #endif