fix short copy handling in copy_mc_pipe_to_iter()
[sfrench/cifs-2.6.git] / drivers / i2c / busses / i2c-designware-common.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Synopsys DesignWare I2C adapter driver.
4  *
5  * Based on the TI DAVINCI I2C adapter driver.
6  *
7  * Copyright (C) 2006 Texas Instruments.
8  * Copyright (C) 2007 MontaVista Software Inc.
9  * Copyright (C) 2009 Provigent Ltd.
10  */
11 #include <linux/acpi.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/errno.h>
17 #include <linux/export.h>
18 #include <linux/i2c.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/regmap.h>
25 #include <linux/swab.h>
26 #include <linux/types.h>
27 #include <linux/units.h>
28
29 #include "i2c-designware-core.h"
30
31 static char *abort_sources[] = {
32         [ABRT_7B_ADDR_NOACK] =
33                 "slave address not acknowledged (7bit mode)",
34         [ABRT_10ADDR1_NOACK] =
35                 "first address byte not acknowledged (10bit mode)",
36         [ABRT_10ADDR2_NOACK] =
37                 "second address byte not acknowledged (10bit mode)",
38         [ABRT_TXDATA_NOACK] =
39                 "data not acknowledged",
40         [ABRT_GCALL_NOACK] =
41                 "no acknowledgement for a general call",
42         [ABRT_GCALL_READ] =
43                 "read after general call",
44         [ABRT_SBYTE_ACKDET] =
45                 "start byte acknowledged",
46         [ABRT_SBYTE_NORSTRT] =
47                 "trying to send start byte when restart is disabled",
48         [ABRT_10B_RD_NORSTRT] =
49                 "trying to read when restart is disabled (10bit mode)",
50         [ABRT_MASTER_DIS] =
51                 "trying to use disabled adapter",
52         [ARB_LOST] =
53                 "lost arbitration",
54         [ABRT_SLAVE_FLUSH_TXFIFO] =
55                 "read command so flush old data in the TX FIFO",
56         [ABRT_SLAVE_ARBLOST] =
57                 "slave lost the bus while transmitting data to a remote master",
58         [ABRT_SLAVE_RD_INTX] =
59                 "incorrect slave-transmitter mode configuration",
60 };
61
62 static int dw_reg_read(void *context, unsigned int reg, unsigned int *val)
63 {
64         struct dw_i2c_dev *dev = context;
65
66         *val = readl_relaxed(dev->base + reg);
67
68         return 0;
69 }
70
71 static int dw_reg_write(void *context, unsigned int reg, unsigned int val)
72 {
73         struct dw_i2c_dev *dev = context;
74
75         writel_relaxed(val, dev->base + reg);
76
77         return 0;
78 }
79
80 static int dw_reg_read_swab(void *context, unsigned int reg, unsigned int *val)
81 {
82         struct dw_i2c_dev *dev = context;
83
84         *val = swab32(readl_relaxed(dev->base + reg));
85
86         return 0;
87 }
88
89 static int dw_reg_write_swab(void *context, unsigned int reg, unsigned int val)
90 {
91         struct dw_i2c_dev *dev = context;
92
93         writel_relaxed(swab32(val), dev->base + reg);
94
95         return 0;
96 }
97
98 static int dw_reg_read_word(void *context, unsigned int reg, unsigned int *val)
99 {
100         struct dw_i2c_dev *dev = context;
101
102         *val = readw_relaxed(dev->base + reg) |
103                 (readw_relaxed(dev->base + reg + 2) << 16);
104
105         return 0;
106 }
107
108 static int dw_reg_write_word(void *context, unsigned int reg, unsigned int val)
109 {
110         struct dw_i2c_dev *dev = context;
111
112         writew_relaxed(val, dev->base + reg);
113         writew_relaxed(val >> 16, dev->base + reg + 2);
114
115         return 0;
116 }
117
118 /**
119  * i2c_dw_init_regmap() - Initialize registers map
120  * @dev: device private data
121  *
122  * Autodetects needed register access mode and creates the regmap with
123  * corresponding read/write callbacks. This must be called before doing any
124  * other register access.
125  */
126 int i2c_dw_init_regmap(struct dw_i2c_dev *dev)
127 {
128         struct regmap_config map_cfg = {
129                 .reg_bits = 32,
130                 .val_bits = 32,
131                 .reg_stride = 4,
132                 .disable_locking = true,
133                 .reg_read = dw_reg_read,
134                 .reg_write = dw_reg_write,
135                 .max_register = DW_IC_COMP_TYPE,
136         };
137         u32 reg;
138         int ret;
139
140         /*
141          * Skip detecting the registers map configuration if the regmap has
142          * already been provided by a higher code.
143          */
144         if (dev->map)
145                 return 0;
146
147         ret = i2c_dw_acquire_lock(dev);
148         if (ret)
149                 return ret;
150
151         reg = readl(dev->base + DW_IC_COMP_TYPE);
152         i2c_dw_release_lock(dev);
153
154         if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU)
155                 map_cfg.max_register = AMD_UCSI_INTR_REG;
156
157         if (reg == swab32(DW_IC_COMP_TYPE_VALUE)) {
158                 map_cfg.reg_read = dw_reg_read_swab;
159                 map_cfg.reg_write = dw_reg_write_swab;
160         } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
161                 map_cfg.reg_read = dw_reg_read_word;
162                 map_cfg.reg_write = dw_reg_write_word;
163         } else if (reg != DW_IC_COMP_TYPE_VALUE) {
164                 dev_err(dev->dev,
165                         "Unknown Synopsys component type: 0x%08x\n", reg);
166                 return -ENODEV;
167         }
168
169         /*
170          * Note we'll check the return value of the regmap IO accessors only
171          * at the probe stage. The rest of the code won't do this because
172          * basically we have MMIO-based regmap so non of the read/write methods
173          * can fail.
174          */
175         dev->map = devm_regmap_init(dev->dev, NULL, dev, &map_cfg);
176         if (IS_ERR(dev->map)) {
177                 dev_err(dev->dev, "Failed to init the registers map\n");
178                 return PTR_ERR(dev->map);
179         }
180
181         return 0;
182 }
183
184 static const u32 supported_speeds[] = {
185         I2C_MAX_HIGH_SPEED_MODE_FREQ,
186         I2C_MAX_FAST_MODE_PLUS_FREQ,
187         I2C_MAX_FAST_MODE_FREQ,
188         I2C_MAX_STANDARD_MODE_FREQ,
189 };
190
191 int i2c_dw_validate_speed(struct dw_i2c_dev *dev)
192 {
193         struct i2c_timings *t = &dev->timings;
194         unsigned int i;
195
196         /*
197          * Only standard mode at 100kHz, fast mode at 400kHz,
198          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
199          */
200         for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) {
201                 if (t->bus_freq_hz == supported_speeds[i])
202                         return 0;
203         }
204
205         dev_err(dev->dev,
206                 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
207                 t->bus_freq_hz);
208
209         return -EINVAL;
210 }
211 EXPORT_SYMBOL_GPL(i2c_dw_validate_speed);
212
213 #ifdef CONFIG_ACPI
214
215 #include <linux/dmi.h>
216
217 /*
218  * The HCNT/LCNT information coming from ACPI should be the most accurate
219  * for given platform. However, some systems get it wrong. On such systems
220  * we get better results by calculating those based on the input clock.
221  */
222 static const struct dmi_system_id i2c_dw_no_acpi_params[] = {
223         {
224                 .ident = "Dell Inspiron 7348",
225                 .matches = {
226                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
227                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
228                 },
229         },
230         {}
231 };
232
233 static void i2c_dw_acpi_params(struct device *device, char method[],
234                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
235 {
236         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
237         acpi_handle handle = ACPI_HANDLE(device);
238         union acpi_object *obj;
239
240         if (dmi_check_system(i2c_dw_no_acpi_params))
241                 return;
242
243         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
244                 return;
245
246         obj = (union acpi_object *)buf.pointer;
247         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
248                 const union acpi_object *objs = obj->package.elements;
249
250                 *hcnt = (u16)objs[0].integer.value;
251                 *lcnt = (u16)objs[1].integer.value;
252                 *sda_hold = (u32)objs[2].integer.value;
253         }
254
255         kfree(buf.pointer);
256 }
257
258 int i2c_dw_acpi_configure(struct device *device)
259 {
260         struct dw_i2c_dev *dev = dev_get_drvdata(device);
261         struct i2c_timings *t = &dev->timings;
262         u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
263
264         /*
265          * Try to get SDA hold time and *CNT values from an ACPI method for
266          * selected speed modes.
267          */
268         i2c_dw_acpi_params(device, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
269         i2c_dw_acpi_params(device, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
270         i2c_dw_acpi_params(device, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
271         i2c_dw_acpi_params(device, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
272
273         switch (t->bus_freq_hz) {
274         case I2C_MAX_STANDARD_MODE_FREQ:
275                 dev->sda_hold_time = ss_ht;
276                 break;
277         case I2C_MAX_FAST_MODE_PLUS_FREQ:
278                 dev->sda_hold_time = fp_ht;
279                 break;
280         case I2C_MAX_HIGH_SPEED_MODE_FREQ:
281                 dev->sda_hold_time = hs_ht;
282                 break;
283         case I2C_MAX_FAST_MODE_FREQ:
284         default:
285                 dev->sda_hold_time = fs_ht;
286                 break;
287         }
288
289         return 0;
290 }
291 EXPORT_SYMBOL_GPL(i2c_dw_acpi_configure);
292
293 static u32 i2c_dw_acpi_round_bus_speed(struct device *device)
294 {
295         u32 acpi_speed;
296         int i;
297
298         acpi_speed = i2c_acpi_find_bus_speed(device);
299         /*
300          * Some DSTDs use a non standard speed, round down to the lowest
301          * standard speed.
302          */
303         for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) {
304                 if (acpi_speed >= supported_speeds[i])
305                         return supported_speeds[i];
306         }
307
308         return 0;
309 }
310
311 #else   /* CONFIG_ACPI */
312
313 static inline u32 i2c_dw_acpi_round_bus_speed(struct device *device) { return 0; }
314
315 #endif  /* CONFIG_ACPI */
316
317 void i2c_dw_adjust_bus_speed(struct dw_i2c_dev *dev)
318 {
319         u32 acpi_speed = i2c_dw_acpi_round_bus_speed(dev->dev);
320         struct i2c_timings *t = &dev->timings;
321
322         /*
323          * Find bus speed from the "clock-frequency" device property, ACPI
324          * or by using fast mode if neither is set.
325          */
326         if (acpi_speed && t->bus_freq_hz)
327                 t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed);
328         else if (acpi_speed || t->bus_freq_hz)
329                 t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed);
330         else
331                 t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
332 }
333 EXPORT_SYMBOL_GPL(i2c_dw_adjust_bus_speed);
334
335 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
336 {
337         /*
338          * DesignWare I2C core doesn't seem to have solid strategy to meet
339          * the tHD;STA timing spec.  Configuring _HCNT based on tHIGH spec
340          * will result in violation of the tHD;STA spec.
341          */
342         if (cond)
343                 /*
344                  * Conditional expression:
345                  *
346                  *   IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
347                  *
348                  * This is based on the DW manuals, and represents an ideal
349                  * configuration.  The resulting I2C bus speed will be
350                  * faster than any of the others.
351                  *
352                  * If your hardware is free from tHD;STA issue, try this one.
353                  */
354                 return DIV_ROUND_CLOSEST(ic_clk * tSYMBOL, MICRO) - 8 + offset;
355         else
356                 /*
357                  * Conditional expression:
358                  *
359                  *   IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
360                  *
361                  * This is just experimental rule; the tHD;STA period turned
362                  * out to be proportinal to (_HCNT + 3).  With this setting,
363                  * we could meet both tHIGH and tHD;STA timing specs.
364                  *
365                  * If unsure, you'd better to take this alternative.
366                  *
367                  * The reason why we need to take into account "tf" here,
368                  * is the same as described in i2c_dw_scl_lcnt().
369                  */
370                 return DIV_ROUND_CLOSEST(ic_clk * (tSYMBOL + tf), MICRO) - 3 + offset;
371 }
372
373 u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
374 {
375         /*
376          * Conditional expression:
377          *
378          *   IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
379          *
380          * DW I2C core starts counting the SCL CNTs for the LOW period
381          * of the SCL clock (tLOW) as soon as it pulls the SCL line.
382          * In order to meet the tLOW timing spec, we need to take into
383          * account the fall time of SCL signal (tf).  Default tf value
384          * should be 0.3 us, for safety.
385          */
386         return DIV_ROUND_CLOSEST(ic_clk * (tLOW + tf), MICRO) - 1 + offset;
387 }
388
389 int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
390 {
391         u32 reg;
392         int ret;
393
394         ret = i2c_dw_acquire_lock(dev);
395         if (ret)
396                 return ret;
397
398         /* Configure SDA Hold Time if required */
399         ret = regmap_read(dev->map, DW_IC_COMP_VERSION, &reg);
400         if (ret)
401                 goto err_release_lock;
402
403         if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
404                 if (!dev->sda_hold_time) {
405                         /* Keep previous hold time setting if no one set it */
406                         ret = regmap_read(dev->map, DW_IC_SDA_HOLD,
407                                           &dev->sda_hold_time);
408                         if (ret)
409                                 goto err_release_lock;
410                 }
411
412                 /*
413                  * Workaround for avoiding TX arbitration lost in case I2C
414                  * slave pulls SDA down "too quickly" after falling edge of
415                  * SCL by enabling non-zero SDA RX hold. Specification says it
416                  * extends incoming SDA low to high transition while SCL is
417                  * high but it appears to help also above issue.
418                  */
419                 if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
420                         dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
421
422                 dev_dbg(dev->dev, "SDA Hold Time TX:RX = %d:%d\n",
423                         dev->sda_hold_time & ~(u32)DW_IC_SDA_HOLD_RX_MASK,
424                         dev->sda_hold_time >> DW_IC_SDA_HOLD_RX_SHIFT);
425         } else if (dev->set_sda_hold_time) {
426                 dev->set_sda_hold_time(dev);
427         } else if (dev->sda_hold_time) {
428                 dev_warn(dev->dev,
429                         "Hardware too old to adjust SDA hold time.\n");
430                 dev->sda_hold_time = 0;
431         }
432
433 err_release_lock:
434         i2c_dw_release_lock(dev);
435
436         return ret;
437 }
438
439 void __i2c_dw_disable(struct dw_i2c_dev *dev)
440 {
441         int timeout = 100;
442         u32 status;
443
444         do {
445                 __i2c_dw_disable_nowait(dev);
446                 /*
447                  * The enable status register may be unimplemented, but
448                  * in that case this test reads zero and exits the loop.
449                  */
450                 regmap_read(dev->map, DW_IC_ENABLE_STATUS, &status);
451                 if ((status & 1) == 0)
452                         return;
453
454                 /*
455                  * Wait 10 times the signaling period of the highest I2C
456                  * transfer supported by the driver (for 400KHz this is
457                  * 25us) as described in the DesignWare I2C databook.
458                  */
459                 usleep_range(25, 250);
460         } while (timeout--);
461
462         dev_warn(dev->dev, "timeout in disabling adapter\n");
463 }
464
465 unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
466 {
467         /*
468          * Clock is not necessary if we got LCNT/HCNT values directly from
469          * the platform code.
470          */
471         if (WARN_ON_ONCE(!dev->get_clk_rate_khz))
472                 return 0;
473         return dev->get_clk_rate_khz(dev);
474 }
475
476 int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare)
477 {
478         int ret;
479
480         if (IS_ERR(dev->clk))
481                 return PTR_ERR(dev->clk);
482
483         if (prepare) {
484                 /* Optional interface clock */
485                 ret = clk_prepare_enable(dev->pclk);
486                 if (ret)
487                         return ret;
488
489                 ret = clk_prepare_enable(dev->clk);
490                 if (ret)
491                         clk_disable_unprepare(dev->pclk);
492
493                 return ret;
494         }
495
496         clk_disable_unprepare(dev->clk);
497         clk_disable_unprepare(dev->pclk);
498
499         return 0;
500 }
501 EXPORT_SYMBOL_GPL(i2c_dw_prepare_clk);
502
503 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev)
504 {
505         int ret;
506
507         if (!dev->acquire_lock)
508                 return 0;
509
510         ret = dev->acquire_lock();
511         if (!ret)
512                 return 0;
513
514         dev_err(dev->dev, "couldn't acquire bus ownership\n");
515
516         return ret;
517 }
518
519 void i2c_dw_release_lock(struct dw_i2c_dev *dev)
520 {
521         if (dev->release_lock)
522                 dev->release_lock();
523 }
524
525 /*
526  * Waiting for bus not busy
527  */
528 int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
529 {
530         u32 status;
531         int ret;
532
533         ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
534                                        !(status & DW_IC_STATUS_ACTIVITY),
535                                        1100, 20000);
536         if (ret) {
537                 dev_warn(dev->dev, "timeout waiting for bus ready\n");
538
539                 i2c_recover_bus(&dev->adapter);
540
541                 regmap_read(dev->map, DW_IC_STATUS, &status);
542                 if (!(status & DW_IC_STATUS_ACTIVITY))
543                         ret = 0;
544         }
545
546         return ret;
547 }
548
549 int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
550 {
551         unsigned long abort_source = dev->abort_source;
552         int i;
553
554         if (abort_source & DW_IC_TX_ABRT_NOACK) {
555                 for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
556                         dev_dbg(dev->dev,
557                                 "%s: %s\n", __func__, abort_sources[i]);
558                 return -EREMOTEIO;
559         }
560
561         for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
562                 dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
563
564         if (abort_source & DW_IC_TX_ARB_LOST)
565                 return -EAGAIN;
566         else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
567                 return -EINVAL; /* wrong msgs[] data */
568         else
569                 return -EIO;
570 }
571
572 int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
573 {
574         u32 param, tx_fifo_depth, rx_fifo_depth;
575         int ret;
576
577         /*
578          * Try to detect the FIFO depth if not set by interface driver,
579          * the depth could be from 2 to 256 from HW spec.
580          */
581         ret = i2c_dw_acquire_lock(dev);
582         if (ret)
583                 return ret;
584
585         ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &param);
586         i2c_dw_release_lock(dev);
587         if (ret)
588                 return ret;
589
590         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
591         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
592         if (!dev->tx_fifo_depth) {
593                 dev->tx_fifo_depth = tx_fifo_depth;
594                 dev->rx_fifo_depth = rx_fifo_depth;
595         } else if (tx_fifo_depth >= 2) {
596                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
597                                 tx_fifo_depth);
598                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
599                                 rx_fifo_depth);
600         }
601
602         return 0;
603 }
604
605 u32 i2c_dw_func(struct i2c_adapter *adap)
606 {
607         struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
608
609         return dev->functionality;
610 }
611
612 void i2c_dw_disable(struct dw_i2c_dev *dev)
613 {
614         u32 dummy;
615         int ret;
616
617         ret = i2c_dw_acquire_lock(dev);
618         if (ret)
619                 return;
620
621         /* Disable controller */
622         __i2c_dw_disable(dev);
623
624         /* Disable all interrupts */
625         regmap_write(dev->map, DW_IC_INTR_MASK, 0);
626         regmap_read(dev->map, DW_IC_CLR_INTR, &dummy);
627
628         i2c_dw_release_lock(dev);
629 }
630
631 void i2c_dw_disable_int(struct dw_i2c_dev *dev)
632 {
633         regmap_write(dev->map, DW_IC_INTR_MASK, 0);
634 }
635
636 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
637 MODULE_LICENSE("GPL");