1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * OMAP Voltage Controller (VC) interface
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 */
7 #include <linux/kernel.h>
8 #include <linux/delay.h>
9 #include <linux/init.h>
10 #include <linux/bug.h>
11 #include <linux/io.h>
12
13 #include <asm/div64.h>
14
15 #include "iomap.h"
16 #include "soc.h"
17 #include "voltage.h"
18 #include "vc.h"
19 #include "prm-regbits-34xx.h"
20 #include "prm-regbits-44xx.h"
21 #include "prm44xx.h"
22 #include "pm.h"
23 #include "scrm44xx.h"
24 #include "control.h"
25
26 #define OMAP4430_VDD_IVA_I2C_DISABLE BIT(14)
27 #define OMAP4430_VDD_MPU_I2C_DISABLE BIT(13)
28 #define OMAP4430_VDD_CORE_I2C_DISABLE BIT(12)
29 #define OMAP4430_VDD_IVA_PRESENCE BIT(9)
30 #define OMAP4430_VDD_MPU_PRESENCE BIT(8)
31 #define OMAP4430_AUTO_CTRL_VDD_IVA(x) ((x) << 4)
32 #define OMAP4430_AUTO_CTRL_VDD_MPU(x) ((x) << 2)
33 #define OMAP4430_AUTO_CTRL_VDD_CORE(x) ((x) << 0)
34 #define OMAP4430_AUTO_CTRL_VDD_RET 2
35
36 #define OMAP4430_VDD_I2C_DISABLE_MASK \
37 (OMAP4430_VDD_IVA_I2C_DISABLE | \
38 OMAP4430_VDD_MPU_I2C_DISABLE | \
39 OMAP4430_VDD_CORE_I2C_DISABLE)
40
41 #define OMAP4_VDD_DEFAULT_VAL \
42 (OMAP4430_VDD_I2C_DISABLE_MASK | \
43 OMAP4430_VDD_IVA_PRESENCE | OMAP4430_VDD_MPU_PRESENCE | \
44 OMAP4430_AUTO_CTRL_VDD_IVA(OMAP4430_AUTO_CTRL_VDD_RET) | \
45 OMAP4430_AUTO_CTRL_VDD_MPU(OMAP4430_AUTO_CTRL_VDD_RET) | \
46 OMAP4430_AUTO_CTRL_VDD_CORE(OMAP4430_AUTO_CTRL_VDD_RET))
47
48 #define OMAP4_VDD_RET_VAL \
49 (OMAP4_VDD_DEFAULT_VAL & ~OMAP4430_VDD_I2C_DISABLE_MASK)
50
51 /**
52 * struct omap_vc_channel_cfg - describe the cfg_channel bitfield
53 * @sa: bit for slave address
54 * @rav: bit for voltage configuration register
55 * @rac: bit for command configuration register
56 * @racen: enable bit for RAC
57 * @cmd: bit for command value set selection
58 *
59 * Channel configuration bits, common for OMAP3+
60 * OMAP3 register: PRM_VC_CH_CONF
61 * OMAP4 register: PRM_VC_CFG_CHANNEL
62 * OMAP5 register: PRM_VC_SMPS_<voltdm>_CONFIG
63 */
64 struct omap_vc_channel_cfg {
65 u8 sa;
66 u8 rav;
67 u8 rac;
68 u8 racen;
69 u8 cmd;
70 };
71
72 static struct omap_vc_channel_cfg vc_default_channel_cfg = {
73 .sa = BIT(0),
74 .rav = BIT(1),
75 .rac = BIT(2),
76 .racen = BIT(3),
77 .cmd = BIT(4),
78 };
79
80 /*
81 * On OMAP3+, all VC channels have the above default bitfield
82 * configuration, except the OMAP4 MPU channel. This appears
83 * to be a freak accident as every other VC channel has the
84 * default configuration, thus creating a mutant channel config.
85 */
86 static struct omap_vc_channel_cfg vc_mutant_channel_cfg = {
87 .sa = BIT(0),
88 .rav = BIT(2),
89 .rac = BIT(3),
90 .racen = BIT(4),
91 .cmd = BIT(1),
92 };
93
94 static struct omap_vc_channel_cfg *vc_cfg_bits;
95
96 /* Default I2C trace length on pcb, 6.3cm. Used for capacitance calculations. */
97 static u32 sr_i2c_pcb_length = 63;
98 #define CFG_CHANNEL_MASK 0x1f
99
100 /**
101 * omap_vc_config_channel - configure VC channel to PMIC mappings
102 * @voltdm: pointer to voltagdomain defining the desired VC channel
103 *
104 * Configures the VC channel to PMIC mappings for the following
105 * PMIC settings
106 * - i2c slave address (SA)
107 * - voltage configuration address (RAV)
108 * - command configuration address (RAC) and enable bit (RACEN)
109 * - command values for ON, ONLP, RET and OFF (CMD)
110 *
111 * This function currently only allows flexible configuration of the
112 * non-default channel. Starting with OMAP4, there are more than 2
113 * channels, with one defined as the default (on OMAP4, it's MPU.)
114 * Only the non-default channel can be configured.
115 */
omap_vc_config_channel(struct voltagedomain * voltdm)116 static int omap_vc_config_channel(struct voltagedomain *voltdm)
117 {
118 struct omap_vc_channel *vc = voltdm->vc;
119
120 /*
121 * For default channel, the only configurable bit is RACEN.
122 * All others must stay at zero (see function comment above.)
123 */
124 if (vc->flags & OMAP_VC_CHANNEL_DEFAULT)
125 vc->cfg_channel &= vc_cfg_bits->racen;
126
127 voltdm->rmw(CFG_CHANNEL_MASK << vc->cfg_channel_sa_shift,
128 vc->cfg_channel << vc->cfg_channel_sa_shift,
129 vc->cfg_channel_reg);
130
131 return 0;
132 }
133
134 /* Voltage scale and accessory APIs */
omap_vc_pre_scale(struct voltagedomain * voltdm,unsigned long target_volt,u8 * target_vsel,u8 * current_vsel)135 int omap_vc_pre_scale(struct voltagedomain *voltdm,
136 unsigned long target_volt,
137 u8 *target_vsel, u8 *current_vsel)
138 {
139 struct omap_vc_channel *vc = voltdm->vc;
140 u32 vc_cmdval;
141
142 /* Check if sufficient pmic info is available for this vdd */
143 if (!voltdm->pmic) {
144 pr_err("%s: Insufficient pmic info to scale the vdd_%s\n",
145 __func__, voltdm->name);
146 return -EINVAL;
147 }
148
149 if (!voltdm->pmic->uv_to_vsel) {
150 pr_err("%s: PMIC function to convert voltage in uV to vsel not registered. Hence unable to scale voltage for vdd_%s\n",
151 __func__, voltdm->name);
152 return -ENODATA;
153 }
154
155 if (!voltdm->read || !voltdm->write) {
156 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
157 __func__, voltdm->name);
158 return -EINVAL;
159 }
160
161 *target_vsel = voltdm->pmic->uv_to_vsel(target_volt);
162 *current_vsel = voltdm->pmic->uv_to_vsel(voltdm->nominal_volt);
163
164 /* Setting the ON voltage to the new target voltage */
165 vc_cmdval = voltdm->read(vc->cmdval_reg);
166 vc_cmdval &= ~vc->common->cmd_on_mask;
167 vc_cmdval |= (*target_vsel << vc->common->cmd_on_shift);
168 voltdm->write(vc_cmdval, vc->cmdval_reg);
169
170 voltdm->vc_param->on = target_volt;
171
172 omap_vp_update_errorgain(voltdm, target_volt);
173
174 return 0;
175 }
176
omap_vc_post_scale(struct voltagedomain * voltdm,unsigned long target_volt,u8 target_vsel,u8 current_vsel)177 void omap_vc_post_scale(struct voltagedomain *voltdm,
178 unsigned long target_volt,
179 u8 target_vsel, u8 current_vsel)
180 {
181 u32 smps_steps = 0, smps_delay = 0;
182
183 smps_steps = abs(target_vsel - current_vsel);
184 /* SMPS slew rate / step size. 2us added as buffer. */
185 smps_delay = ((smps_steps * voltdm->pmic->step_size) /
186 voltdm->pmic->slew_rate) + 2;
187 udelay(smps_delay);
188 }
189
190 /* vc_bypass_scale - VC bypass method of voltage scaling */
omap_vc_bypass_scale(struct voltagedomain * voltdm,unsigned long target_volt)191 int omap_vc_bypass_scale(struct voltagedomain *voltdm,
192 unsigned long target_volt)
193 {
194 struct omap_vc_channel *vc = voltdm->vc;
195 u32 loop_cnt = 0, retries_cnt = 0;
196 u32 vc_valid, vc_bypass_val_reg, vc_bypass_value;
197 u8 target_vsel, current_vsel;
198 int ret;
199
200 ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, ¤t_vsel);
201 if (ret)
202 return ret;
203
204 vc_valid = vc->common->valid;
205 vc_bypass_val_reg = vc->common->bypass_val_reg;
206 vc_bypass_value = (target_vsel << vc->common->data_shift) |
207 (vc->volt_reg_addr << vc->common->regaddr_shift) |
208 (vc->i2c_slave_addr << vc->common->slaveaddr_shift);
209
210 voltdm->write(vc_bypass_value, vc_bypass_val_reg);
211 voltdm->write(vc_bypass_value | vc_valid, vc_bypass_val_reg);
212
213 vc_bypass_value = voltdm->read(vc_bypass_val_reg);
214 /*
215 * Loop till the bypass command is acknowledged from the SMPS.
216 * NOTE: This is legacy code. The loop count and retry count needs
217 * to be revisited.
218 */
219 while (!(vc_bypass_value & vc_valid)) {
220 loop_cnt++;
221
222 if (retries_cnt > 10) {
223 pr_warn("%s: Retry count exceeded\n", __func__);
224 return -ETIMEDOUT;
225 }
226
227 if (loop_cnt > 50) {
228 retries_cnt++;
229 loop_cnt = 0;
230 udelay(10);
231 }
232 vc_bypass_value = voltdm->read(vc_bypass_val_reg);
233 }
234
235 omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
236 return 0;
237 }
238
239 /* Convert microsecond value to number of 32kHz clock cycles */
omap_usec_to_32k(u32 usec)240 static inline u32 omap_usec_to_32k(u32 usec)
241 {
242 return DIV_ROUND_UP_ULL(32768ULL * (u64)usec, 1000000ULL);
243 }
244
245 struct omap3_vc_timings {
246 u32 voltsetup1;
247 u32 voltsetup2;
248 };
249
250 struct omap3_vc {
251 struct voltagedomain *vd;
252 u32 voltctrl;
253 u32 voltsetup1;
254 u32 voltsetup2;
255 struct omap3_vc_timings timings[2];
256 };
257 static struct omap3_vc vc;
258
omap3_vc_set_pmic_signaling(int core_next_state)259 void omap3_vc_set_pmic_signaling(int core_next_state)
260 {
261 struct voltagedomain *vd = vc.vd;
262 struct omap3_vc_timings *c = vc.timings;
263 u32 voltctrl, voltsetup1, voltsetup2;
264
265 voltctrl = vc.voltctrl;
266 voltsetup1 = vc.voltsetup1;
267 voltsetup2 = vc.voltsetup2;
268
269 switch (core_next_state) {
270 case PWRDM_POWER_OFF:
271 voltctrl &= ~(OMAP3430_PRM_VOLTCTRL_AUTO_RET |
272 OMAP3430_PRM_VOLTCTRL_AUTO_SLEEP);
273 voltctrl |= OMAP3430_PRM_VOLTCTRL_AUTO_OFF;
274 if (voltctrl & OMAP3430_PRM_VOLTCTRL_SEL_OFF)
275 voltsetup2 = c->voltsetup2;
276 else
277 voltsetup1 = c->voltsetup1;
278 break;
279 case PWRDM_POWER_RET:
280 default:
281 c++;
282 voltctrl &= ~(OMAP3430_PRM_VOLTCTRL_AUTO_OFF |
283 OMAP3430_PRM_VOLTCTRL_AUTO_SLEEP);
284 voltctrl |= OMAP3430_PRM_VOLTCTRL_AUTO_RET;
285 voltsetup1 = c->voltsetup1;
286 break;
287 }
288
289 if (voltctrl != vc.voltctrl) {
290 vd->write(voltctrl, OMAP3_PRM_VOLTCTRL_OFFSET);
291 vc.voltctrl = voltctrl;
292 }
293 if (voltsetup1 != vc.voltsetup1) {
294 vd->write(c->voltsetup1,
295 OMAP3_PRM_VOLTSETUP1_OFFSET);
296 vc.voltsetup1 = voltsetup1;
297 }
298 if (voltsetup2 != vc.voltsetup2) {
299 vd->write(c->voltsetup2,
300 OMAP3_PRM_VOLTSETUP2_OFFSET);
301 vc.voltsetup2 = voltsetup2;
302 }
303 }
304
omap4_vc_set_pmic_signaling(int core_next_state)305 void omap4_vc_set_pmic_signaling(int core_next_state)
306 {
307 struct voltagedomain *vd = vc.vd;
308 u32 val;
309
310 if (!vd)
311 return;
312
313 switch (core_next_state) {
314 case PWRDM_POWER_RET:
315 val = OMAP4_VDD_RET_VAL;
316 break;
317 default:
318 val = OMAP4_VDD_DEFAULT_VAL;
319 break;
320 }
321
322 vd->write(val, OMAP4_PRM_VOLTCTRL_OFFSET);
323 }
324
325 /*
326 * Configure signal polarity for sys_clkreq and sys_off_mode pins
327 * as the default values are wrong and can cause the system to hang
328 * if any twl4030 scripts are loaded.
329 */
omap3_vc_init_pmic_signaling(struct voltagedomain * voltdm)330 static void __init omap3_vc_init_pmic_signaling(struct voltagedomain *voltdm)
331 {
332 u32 val;
333
334 if (vc.vd)
335 return;
336
337 vc.vd = voltdm;
338
339 val = voltdm->read(OMAP3_PRM_POLCTRL_OFFSET);
340 if (!(val & OMAP3430_PRM_POLCTRL_CLKREQ_POL) ||
341 (val & OMAP3430_PRM_POLCTRL_OFFMODE_POL)) {
342 val |= OMAP3430_PRM_POLCTRL_CLKREQ_POL;
343 val &= ~OMAP3430_PRM_POLCTRL_OFFMODE_POL;
344 pr_debug("PM: fixing sys_clkreq and sys_off_mode polarity to 0x%x\n",
345 val);
346 voltdm->write(val, OMAP3_PRM_POLCTRL_OFFSET);
347 }
348
349 /*
350 * By default let's use I2C4 signaling for retention idle
351 * and sys_off_mode pin signaling for off idle. This way we
352 * have sys_clk_req pin go down for retention and both
353 * sys_clk_req and sys_off_mode pins will go down for off
354 * idle. And we can also scale voltages to zero for off-idle.
355 * Note that no actual voltage scaling during off-idle will
356 * happen unless the board specific twl4030 PMIC scripts are
357 * loaded. See also omap_vc_i2c_init for comments regarding
358 * erratum i531.
359 */
360 val = voltdm->read(OMAP3_PRM_VOLTCTRL_OFFSET);
361 if (!(val & OMAP3430_PRM_VOLTCTRL_SEL_OFF)) {
362 val |= OMAP3430_PRM_VOLTCTRL_SEL_OFF;
363 pr_debug("PM: setting voltctrl sys_off_mode signaling to 0x%x\n",
364 val);
365 voltdm->write(val, OMAP3_PRM_VOLTCTRL_OFFSET);
366 }
367 vc.voltctrl = val;
368
369 omap3_vc_set_pmic_signaling(PWRDM_POWER_ON);
370 }
371
omap3_init_voltsetup1(struct voltagedomain * voltdm,struct omap3_vc_timings * c,u32 idle)372 static void omap3_init_voltsetup1(struct voltagedomain *voltdm,
373 struct omap3_vc_timings *c, u32 idle)
374 {
375 unsigned long val;
376
377 val = (voltdm->vc_param->on - idle) / voltdm->pmic->slew_rate;
378 val *= voltdm->sys_clk.rate / 8 / 1000000 + 1;
379 val <<= __ffs(voltdm->vfsm->voltsetup_mask);
380 c->voltsetup1 &= ~voltdm->vfsm->voltsetup_mask;
381 c->voltsetup1 |= val;
382 }
383
384 /**
385 * omap3_set_i2c_timings - sets i2c sleep timings for a channel
386 * @voltdm: channel to configure
387 * @off_mode: select whether retention or off mode values used
388 *
389 * Calculates and sets up voltage controller to use I2C based
390 * voltage scaling for sleep modes. This can be used for either off mode
391 * or retention. Off mode has additionally an option to use sys_off_mode
392 * pad, which uses a global signal to program the whole power IC to
393 * off-mode.
394 *
395 * Note that pmic is not controlling the voltage scaling during
396 * retention signaled over I2C4, so we can keep voltsetup2 as 0.
397 * And the oscillator is not shut off over I2C4, so no need to
398 * set clksetup.
399 */
omap3_set_i2c_timings(struct voltagedomain * voltdm)400 static void omap3_set_i2c_timings(struct voltagedomain *voltdm)
401 {
402 struct omap3_vc_timings *c = vc.timings;
403
404 /* Configure PRWDM_POWER_OFF over I2C4 */
405 omap3_init_voltsetup1(voltdm, c, voltdm->vc_param->off);
406 c++;
407 /* Configure PRWDM_POWER_RET over I2C4 */
408 omap3_init_voltsetup1(voltdm, c, voltdm->vc_param->ret);
409 }
410
411 /**
412 * omap3_set_off_timings - sets off-mode timings for a channel
413 * @voltdm: channel to configure
414 *
415 * Calculates and sets up off-mode timings for a channel. Off-mode
416 * can use either I2C based voltage scaling, or alternatively
417 * sys_off_mode pad can be used to send a global command to power IC.n,
418 * sys_off_mode has the additional benefit that voltages can be
419 * scaled to zero volt level with TWL4030 / TWL5030, I2C can only
420 * scale to 600mV.
421 *
422 * Note that omap is not controlling the voltage scaling during
423 * off idle signaled by sys_off_mode, so we can keep voltsetup1
424 * as 0.
425 */
omap3_set_off_timings(struct voltagedomain * voltdm)426 static void omap3_set_off_timings(struct voltagedomain *voltdm)
427 {
428 struct omap3_vc_timings *c = vc.timings;
429 u32 tstart, tshut, clksetup, voltoffset;
430
431 if (c->voltsetup2)
432 return;
433
434 omap_pm_get_oscillator(&tstart, &tshut);
435 if (tstart == ULONG_MAX) {
436 pr_debug("PM: oscillator start-up time not initialized, using 10ms\n");
437 clksetup = omap_usec_to_32k(10000);
438 } else {
439 clksetup = omap_usec_to_32k(tstart);
440 }
441
442 /*
443 * For twl4030 errata 27, we need to allow minimum ~488.32 us wait to
444 * switch from HFCLKIN to internal oscillator. That means timings
445 * have voltoffset fixed to 0xa in rounded up 32 KiHz cycles. And
446 * that means we can calculate the value based on the oscillator
447 * start-up time since voltoffset2 = clksetup - voltoffset.
448 */
449 voltoffset = omap_usec_to_32k(488);
450 c->voltsetup2 = clksetup - voltoffset;
451 voltdm->write(clksetup, OMAP3_PRM_CLKSETUP_OFFSET);
452 voltdm->write(voltoffset, OMAP3_PRM_VOLTOFFSET_OFFSET);
453 }
454
omap3_vc_init_channel(struct voltagedomain * voltdm)455 static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
456 {
457 omap3_vc_init_pmic_signaling(voltdm);
458 omap3_set_off_timings(voltdm);
459 omap3_set_i2c_timings(voltdm);
460 }
461
462 /**
463 * omap4_calc_volt_ramp - calculates voltage ramping delays on omap4
464 * @voltdm: channel to calculate values for
465 * @voltage_diff: voltage difference in microvolts
466 *
467 * Calculates voltage ramp prescaler + counter values for a voltage
468 * difference on omap4. Returns a field value suitable for writing to
469 * VOLTSETUP register for a channel in following format:
470 * bits[8:9] prescaler ... bits[0:5] counter. See OMAP4 TRM for reference.
471 */
omap4_calc_volt_ramp(struct voltagedomain * voltdm,u32 voltage_diff)472 static u32 omap4_calc_volt_ramp(struct voltagedomain *voltdm, u32 voltage_diff)
473 {
474 u32 prescaler;
475 u32 cycles;
476 u32 time;
477
478 time = voltage_diff / voltdm->pmic->slew_rate;
479
480 cycles = voltdm->sys_clk.rate / 1000 * time / 1000;
481
482 cycles /= 64;
483 prescaler = 0;
484
485 /* shift to next prescaler until no overflow */
486
487 /* scale for div 256 = 64 * 4 */
488 if (cycles > 63) {
489 cycles /= 4;
490 prescaler++;
491 }
492
493 /* scale for div 512 = 256 * 2 */
494 if (cycles > 63) {
495 cycles /= 2;
496 prescaler++;
497 }
498
499 /* scale for div 2048 = 512 * 4 */
500 if (cycles > 63) {
501 cycles /= 4;
502 prescaler++;
503 }
504
505 /* check for overflow => invalid ramp time */
506 if (cycles > 63) {
507 pr_warn("%s: invalid setuptime for vdd_%s\n", __func__,
508 voltdm->name);
509 return 0;
510 }
511
512 cycles++;
513
514 return (prescaler << OMAP4430_RAMP_UP_PRESCAL_SHIFT) |
515 (cycles << OMAP4430_RAMP_UP_COUNT_SHIFT);
516 }
517
518 /**
519 * omap4_usec_to_val_scrm - convert microsecond value to SCRM module bitfield
520 * @usec: microseconds
521 * @shift: number of bits to shift left
522 * @mask: bitfield mask
523 *
524 * Converts microsecond value to OMAP4 SCRM bitfield. Bitfield is
525 * shifted to requested position, and checked agains the mask value.
526 * If larger, forced to the max value of the field (i.e. the mask itself.)
527 * Returns the SCRM bitfield value.
528 */
omap4_usec_to_val_scrm(u32 usec,int shift,u32 mask)529 static u32 omap4_usec_to_val_scrm(u32 usec, int shift, u32 mask)
530 {
531 u32 val;
532
533 val = omap_usec_to_32k(usec) << shift;
534
535 /* Check for overflow, if yes, force to max value */
536 if (val > mask)
537 val = mask;
538
539 return val;
540 }
541
542 /**
543 * omap4_set_timings - set voltage ramp timings for a channel
544 * @voltdm: channel to configure
545 * @off_mode: whether off-mode values are used
546 *
547 * Calculates and sets the voltage ramp up / down values for a channel.
548 */
omap4_set_timings(struct voltagedomain * voltdm,bool off_mode)549 static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
550 {
551 u32 val;
552 u32 ramp;
553 int offset;
554 u32 tstart, tshut;
555
556 if (off_mode) {
557 ramp = omap4_calc_volt_ramp(voltdm,
558 voltdm->vc_param->on - voltdm->vc_param->off);
559 offset = voltdm->vfsm->voltsetup_off_reg;
560 } else {
561 ramp = omap4_calc_volt_ramp(voltdm,
562 voltdm->vc_param->on - voltdm->vc_param->ret);
563 offset = voltdm->vfsm->voltsetup_reg;
564 }
565
566 if (!ramp)
567 return;
568
569 val = voltdm->read(offset);
570
571 val |= ramp << OMAP4430_RAMP_DOWN_COUNT_SHIFT;
572
573 val |= ramp << OMAP4430_RAMP_UP_COUNT_SHIFT;
574
575 voltdm->write(val, offset);
576
577 omap_pm_get_oscillator(&tstart, &tshut);
578
579 val = omap4_usec_to_val_scrm(tstart, OMAP4_SETUPTIME_SHIFT,
580 OMAP4_SETUPTIME_MASK);
581 val |= omap4_usec_to_val_scrm(tshut, OMAP4_DOWNTIME_SHIFT,
582 OMAP4_DOWNTIME_MASK);
583
584 writel_relaxed(val, OMAP4_SCRM_CLKSETUPTIME);
585 }
586
omap4_vc_init_pmic_signaling(struct voltagedomain * voltdm)587 static void __init omap4_vc_init_pmic_signaling(struct voltagedomain *voltdm)
588 {
589 if (vc.vd)
590 return;
591
592 vc.vd = voltdm;
593 voltdm->write(OMAP4_VDD_DEFAULT_VAL, OMAP4_PRM_VOLTCTRL_OFFSET);
594 }
595
596 /* OMAP4 specific voltage init functions */
omap4_vc_init_channel(struct voltagedomain * voltdm)597 static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
598 {
599 omap4_vc_init_pmic_signaling(voltdm);
600 omap4_set_timings(voltdm, true);
601 omap4_set_timings(voltdm, false);
602 }
603
604 struct i2c_init_data {
605 u8 loadbits;
606 u8 load;
607 u8 hsscll_38_4;
608 u8 hsscll_26;
609 u8 hsscll_19_2;
610 u8 hsscll_16_8;
611 u8 hsscll_12;
612 };
613
614 static const struct i2c_init_data omap4_i2c_timing_data[] __initconst = {
615 {
616 .load = 50,
617 .loadbits = 0x3,
618 .hsscll_38_4 = 13,
619 .hsscll_26 = 11,
620 .hsscll_19_2 = 9,
621 .hsscll_16_8 = 9,
622 .hsscll_12 = 8,
623 },
624 {
625 .load = 25,
626 .loadbits = 0x2,
627 .hsscll_38_4 = 13,
628 .hsscll_26 = 11,
629 .hsscll_19_2 = 9,
630 .hsscll_16_8 = 9,
631 .hsscll_12 = 8,
632 },
633 {
634 .load = 12,
635 .loadbits = 0x1,
636 .hsscll_38_4 = 11,
637 .hsscll_26 = 10,
638 .hsscll_19_2 = 9,
639 .hsscll_16_8 = 9,
640 .hsscll_12 = 8,
641 },
642 {
643 .load = 0,
644 .loadbits = 0x0,
645 .hsscll_38_4 = 12,
646 .hsscll_26 = 10,
647 .hsscll_19_2 = 9,
648 .hsscll_16_8 = 8,
649 .hsscll_12 = 8,
650 },
651 };
652
653 /**
654 * omap4_vc_i2c_timing_init - sets up board I2C timing parameters
655 * @voltdm: voltagedomain pointer to get data from
656 *
657 * Use PMIC + board supplied settings for calculating the total I2C
658 * channel capacitance and set the timing parameters based on this.
659 * Pre-calculated values are provided in data tables, as it is not
660 * too straightforward to calculate these runtime.
661 */
omap4_vc_i2c_timing_init(struct voltagedomain * voltdm)662 static void __init omap4_vc_i2c_timing_init(struct voltagedomain *voltdm)
663 {
664 u32 capacitance;
665 u32 val;
666 u16 hsscll;
667 const struct i2c_init_data *i2c_data;
668
669 if (!voltdm->pmic->i2c_high_speed) {
670 pr_info("%s: using bootloader low-speed timings\n", __func__);
671 return;
672 }
673
674 /* PCB trace capacitance, 0.125pF / mm => mm / 8 */
675 capacitance = DIV_ROUND_UP(sr_i2c_pcb_length, 8);
676
677 /* OMAP pad capacitance */
678 capacitance += 4;
679
680 /* PMIC pad capacitance */
681 capacitance += voltdm->pmic->i2c_pad_load;
682
683 /* Search for capacitance match in the table */
684 i2c_data = omap4_i2c_timing_data;
685
686 while (i2c_data->load > capacitance)
687 i2c_data++;
688
689 /* Select proper values based on sysclk frequency */
690 switch (voltdm->sys_clk.rate) {
691 case 38400000:
692 hsscll = i2c_data->hsscll_38_4;
693 break;
694 case 26000000:
695 hsscll = i2c_data->hsscll_26;
696 break;
697 case 19200000:
698 hsscll = i2c_data->hsscll_19_2;
699 break;
700 case 16800000:
701 hsscll = i2c_data->hsscll_16_8;
702 break;
703 case 12000000:
704 hsscll = i2c_data->hsscll_12;
705 break;
706 default:
707 pr_warn("%s: unsupported sysclk rate: %d!\n", __func__,
708 voltdm->sys_clk.rate);
709 return;
710 }
711
712 /* Loadbits define pull setup for the I2C channels */
713 val = i2c_data->loadbits << 25 | i2c_data->loadbits << 29;
714
715 /* Write to SYSCTRL_PADCONF_WKUP_CTRL_I2C_2 to setup I2C pull */
716 writel_relaxed(val, OMAP2_L4_IO_ADDRESS(OMAP4_CTRL_MODULE_PAD_WKUP +
717 OMAP4_CTRL_MODULE_PAD_WKUP_CONTROL_I2C_2));
718
719 /* HSSCLH can always be zero */
720 val = hsscll << OMAP4430_HSSCLL_SHIFT;
721 val |= (0x28 << OMAP4430_SCLL_SHIFT | 0x2c << OMAP4430_SCLH_SHIFT);
722
723 /* Write setup times to I2C config register */
724 voltdm->write(val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
725 }
726
727
728
729 /**
730 * omap_vc_i2c_init - initialize I2C interface to PMIC
731 * @voltdm: voltage domain containing VC data
732 *
733 * Use PMIC supplied settings for I2C high-speed mode and
734 * master code (if set) and program the VC I2C configuration
735 * register.
736 *
737 * The VC I2C configuration is common to all VC channels,
738 * so this function only configures I2C for the first VC
739 * channel registers. All other VC channels will use the
740 * same configuration.
741 */
omap_vc_i2c_init(struct voltagedomain * voltdm)742 static void __init omap_vc_i2c_init(struct voltagedomain *voltdm)
743 {
744 struct omap_vc_channel *vc = voltdm->vc;
745 static bool initialized;
746 static bool i2c_high_speed;
747 u8 mcode;
748
749 if (initialized) {
750 if (voltdm->pmic->i2c_high_speed != i2c_high_speed)
751 pr_warn("%s: I2C config for vdd_%s does not match other channels (%u).\n",
752 __func__, voltdm->name, i2c_high_speed);
753 return;
754 }
755
756 /*
757 * Note that for omap3 OMAP3430_SREN_MASK clears SREN to work around
758 * erratum i531 "Extra Power Consumed When Repeated Start Operation
759 * Mode Is Enabled on I2C Interface Dedicated for Smart Reflex (I2C4)".
760 * Otherwise I2C4 eventually leads into about 23mW extra power being
761 * consumed even during off idle using VMODE.
762 */
763 i2c_high_speed = voltdm->pmic->i2c_high_speed;
764 if (i2c_high_speed)
765 voltdm->rmw(vc->common->i2c_cfg_clear_mask,
766 vc->common->i2c_cfg_hsen_mask,
767 vc->common->i2c_cfg_reg);
768
769 mcode = voltdm->pmic->i2c_mcode;
770 if (mcode)
771 voltdm->rmw(vc->common->i2c_mcode_mask,
772 mcode << __ffs(vc->common->i2c_mcode_mask),
773 vc->common->i2c_cfg_reg);
774
775 if (cpu_is_omap44xx())
776 omap4_vc_i2c_timing_init(voltdm);
777
778 initialized = true;
779 }
780
781 /**
782 * omap_vc_calc_vsel - calculate vsel value for a channel
783 * @voltdm: channel to calculate value for
784 * @uvolt: microvolt value to convert to vsel
785 *
786 * Converts a microvolt value to vsel value for the used PMIC.
787 * This checks whether the microvolt value is out of bounds, and
788 * adjusts the value accordingly. If unsupported value detected,
789 * warning is thrown.
790 */
omap_vc_calc_vsel(struct voltagedomain * voltdm,u32 uvolt)791 static u8 omap_vc_calc_vsel(struct voltagedomain *voltdm, u32 uvolt)
792 {
793 if (voltdm->pmic->vddmin > uvolt)
794 uvolt = voltdm->pmic->vddmin;
795 if (voltdm->pmic->vddmax < uvolt) {
796 WARN(1, "%s: voltage not supported by pmic: %u vs max %u\n",
797 __func__, uvolt, voltdm->pmic->vddmax);
798 /* Lets try maximum value anyway */
799 uvolt = voltdm->pmic->vddmax;
800 }
801
802 return voltdm->pmic->uv_to_vsel(uvolt);
803 }
804
omap_vc_init_channel(struct voltagedomain * voltdm)805 void __init omap_vc_init_channel(struct voltagedomain *voltdm)
806 {
807 struct omap_vc_channel *vc = voltdm->vc;
808 u8 on_vsel, onlp_vsel, ret_vsel, off_vsel;
809 u32 val;
810
811 if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
812 pr_err("%s: No PMIC info for vdd_%s\n", __func__, voltdm->name);
813 return;
814 }
815
816 if (!voltdm->read || !voltdm->write) {
817 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
818 __func__, voltdm->name);
819 return;
820 }
821
822 vc->cfg_channel = 0;
823 if (vc->flags & OMAP_VC_CHANNEL_CFG_MUTANT)
824 vc_cfg_bits = &vc_mutant_channel_cfg;
825 else
826 vc_cfg_bits = &vc_default_channel_cfg;
827
828 /* get PMIC/board specific settings */
829 vc->i2c_slave_addr = voltdm->pmic->i2c_slave_addr;
830 vc->volt_reg_addr = voltdm->pmic->volt_reg_addr;
831 vc->cmd_reg_addr = voltdm->pmic->cmd_reg_addr;
832
833 /* Configure the i2c slave address for this VC */
834 voltdm->rmw(vc->smps_sa_mask,
835 vc->i2c_slave_addr << __ffs(vc->smps_sa_mask),
836 vc->smps_sa_reg);
837 vc->cfg_channel |= vc_cfg_bits->sa;
838
839 /*
840 * Configure the PMIC register addresses.
841 */
842 voltdm->rmw(vc->smps_volra_mask,
843 vc->volt_reg_addr << __ffs(vc->smps_volra_mask),
844 vc->smps_volra_reg);
845 vc->cfg_channel |= vc_cfg_bits->rav;
846
847 if (vc->cmd_reg_addr) {
848 voltdm->rmw(vc->smps_cmdra_mask,
849 vc->cmd_reg_addr << __ffs(vc->smps_cmdra_mask),
850 vc->smps_cmdra_reg);
851 vc->cfg_channel |= vc_cfg_bits->rac;
852 }
853
854 if (vc->cmd_reg_addr == vc->volt_reg_addr)
855 vc->cfg_channel |= vc_cfg_bits->racen;
856
857 /* Set up the on, inactive, retention and off voltage */
858 on_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->on);
859 onlp_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->onlp);
860 ret_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->ret);
861 off_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->off);
862
863 val = ((on_vsel << vc->common->cmd_on_shift) |
864 (onlp_vsel << vc->common->cmd_onlp_shift) |
865 (ret_vsel << vc->common->cmd_ret_shift) |
866 (off_vsel << vc->common->cmd_off_shift));
867 voltdm->write(val, vc->cmdval_reg);
868 vc->cfg_channel |= vc_cfg_bits->cmd;
869
870 /* Channel configuration */
871 omap_vc_config_channel(voltdm);
872
873 omap_vc_i2c_init(voltdm);
874
875 if (cpu_is_omap34xx())
876 omap3_vc_init_channel(voltdm);
877 else if (cpu_is_omap44xx())
878 omap4_vc_init_channel(voltdm);
879 }
880