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 */
64struct omap_vc_channel_cfg {
65	u8 sa;
66	u8 rav;
67	u8 rac;
68	u8 racen;
69	u8 cmd;
70};
71
72static 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 */
86static 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
94static struct omap_vc_channel_cfg *vc_cfg_bits;
95
96/* Default I2C trace length on pcb, 6.3cm. Used for capacitance calculations. */
97static 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 */
116static 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 */
135int 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
177void 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 */
191int 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, &current_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 */
240static inline u32 omap_usec_to_32k(u32 usec)
241{
242	return DIV_ROUND_UP_ULL(32768ULL * (u64)usec, 1000000ULL);
243}
244
245struct omap3_vc_timings {
246	u32 voltsetup1;
247	u32 voltsetup2;
248};
249
250struct omap3_vc {
251	struct voltagedomain *vd;
252	u32 voltctrl;
253	u32 voltsetup1;
254	u32 voltsetup2;
255	struct omap3_vc_timings timings[2];
256};
257static struct omap3_vc vc;
258
259void 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
305void 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 */
330static 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
372static 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 */
400static 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 */
426static 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
455static 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 */
472static 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 */
529static 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 */
549static 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
587static 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 */
597static 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
604struct 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
614static 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 */
662static 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 */
742static 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 */
791static 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
805void __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