xref: /linux/arch/arm/mach-omap2/vc.c (revision 3839a7460721b87501134697b7b90c45dcc7825d)
1 /*
2  * OMAP Voltage Controller (VC) interface
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  *
6  * This file is licensed under the terms of the GNU General Public
7  * License version 2. This program is licensed "as is" without any
8  * warranty of any kind, whether express or implied.
9  */
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/bug.h>
14 #include <linux/io.h>
15 
16 #include <asm/div64.h>
17 
18 #include "iomap.h"
19 #include "soc.h"
20 #include "voltage.h"
21 #include "vc.h"
22 #include "prm-regbits-34xx.h"
23 #include "prm-regbits-44xx.h"
24 #include "prm44xx.h"
25 #include "pm.h"
26 #include "scrm44xx.h"
27 #include "control.h"
28 
29 #define OMAP4430_VDD_IVA_I2C_DISABLE		BIT(14)
30 #define OMAP4430_VDD_MPU_I2C_DISABLE		BIT(13)
31 #define OMAP4430_VDD_CORE_I2C_DISABLE		BIT(12)
32 #define OMAP4430_VDD_IVA_PRESENCE		BIT(9)
33 #define OMAP4430_VDD_MPU_PRESENCE		BIT(8)
34 #define OMAP4430_AUTO_CTRL_VDD_IVA(x)		((x) << 4)
35 #define OMAP4430_AUTO_CTRL_VDD_MPU(x)		((x) << 2)
36 #define OMAP4430_AUTO_CTRL_VDD_CORE(x)		((x) << 0)
37 #define OMAP4430_AUTO_CTRL_VDD_RET		2
38 
39 #define OMAP4430_VDD_I2C_DISABLE_MASK	\
40 	(OMAP4430_VDD_IVA_I2C_DISABLE | \
41 	 OMAP4430_VDD_MPU_I2C_DISABLE | \
42 	 OMAP4430_VDD_CORE_I2C_DISABLE)
43 
44 #define OMAP4_VDD_DEFAULT_VAL	\
45 	(OMAP4430_VDD_I2C_DISABLE_MASK | \
46 	 OMAP4430_VDD_IVA_PRESENCE | OMAP4430_VDD_MPU_PRESENCE | \
47 	 OMAP4430_AUTO_CTRL_VDD_IVA(OMAP4430_AUTO_CTRL_VDD_RET) | \
48 	 OMAP4430_AUTO_CTRL_VDD_MPU(OMAP4430_AUTO_CTRL_VDD_RET) | \
49 	 OMAP4430_AUTO_CTRL_VDD_CORE(OMAP4430_AUTO_CTRL_VDD_RET))
50 
51 #define OMAP4_VDD_RET_VAL	\
52 	(OMAP4_VDD_DEFAULT_VAL & ~OMAP4430_VDD_I2C_DISABLE_MASK)
53 
54 /**
55  * struct omap_vc_channel_cfg - describe the cfg_channel bitfield
56  * @sa: bit for slave address
57  * @rav: bit for voltage configuration register
58  * @rac: bit for command configuration register
59  * @racen: enable bit for RAC
60  * @cmd: bit for command value set selection
61  *
62  * Channel configuration bits, common for OMAP3+
63  * OMAP3 register: PRM_VC_CH_CONF
64  * OMAP4 register: PRM_VC_CFG_CHANNEL
65  * OMAP5 register: PRM_VC_SMPS_<voltdm>_CONFIG
66  */
67 struct omap_vc_channel_cfg {
68 	u8 sa;
69 	u8 rav;
70 	u8 rac;
71 	u8 racen;
72 	u8 cmd;
73 };
74 
75 static struct omap_vc_channel_cfg vc_default_channel_cfg = {
76 	.sa    = BIT(0),
77 	.rav   = BIT(1),
78 	.rac   = BIT(2),
79 	.racen = BIT(3),
80 	.cmd   = BIT(4),
81 };
82 
83 /*
84  * On OMAP3+, all VC channels have the above default bitfield
85  * configuration, except the OMAP4 MPU channel.  This appears
86  * to be a freak accident as every other VC channel has the
87  * default configuration, thus creating a mutant channel config.
88  */
89 static struct omap_vc_channel_cfg vc_mutant_channel_cfg = {
90 	.sa    = BIT(0),
91 	.rav   = BIT(2),
92 	.rac   = BIT(3),
93 	.racen = BIT(4),
94 	.cmd   = BIT(1),
95 };
96 
97 static struct omap_vc_channel_cfg *vc_cfg_bits;
98 
99 /* Default I2C trace length on pcb, 6.3cm. Used for capacitance calculations. */
100 static u32 sr_i2c_pcb_length = 63;
101 #define CFG_CHANNEL_MASK 0x1f
102 
103 /**
104  * omap_vc_config_channel - configure VC channel to PMIC mappings
105  * @voltdm: pointer to voltagdomain defining the desired VC channel
106  *
107  * Configures the VC channel to PMIC mappings for the following
108  * PMIC settings
109  * - i2c slave address (SA)
110  * - voltage configuration address (RAV)
111  * - command configuration address (RAC) and enable bit (RACEN)
112  * - command values for ON, ONLP, RET and OFF (CMD)
113  *
114  * This function currently only allows flexible configuration of the
115  * non-default channel.  Starting with OMAP4, there are more than 2
116  * channels, with one defined as the default (on OMAP4, it's MPU.)
117  * Only the non-default channel can be configured.
118  */
119 static int omap_vc_config_channel(struct voltagedomain *voltdm)
120 {
121 	struct omap_vc_channel *vc = voltdm->vc;
122 
123 	/*
124 	 * For default channel, the only configurable bit is RACEN.
125 	 * All others must stay at zero (see function comment above.)
126 	 */
127 	if (vc->flags & OMAP_VC_CHANNEL_DEFAULT)
128 		vc->cfg_channel &= vc_cfg_bits->racen;
129 
130 	voltdm->rmw(CFG_CHANNEL_MASK << vc->cfg_channel_sa_shift,
131 		    vc->cfg_channel << vc->cfg_channel_sa_shift,
132 		    vc->cfg_channel_reg);
133 
134 	return 0;
135 }
136 
137 /* Voltage scale and accessory APIs */
138 int omap_vc_pre_scale(struct voltagedomain *voltdm,
139 		      unsigned long target_volt,
140 		      u8 *target_vsel, u8 *current_vsel)
141 {
142 	struct omap_vc_channel *vc = voltdm->vc;
143 	u32 vc_cmdval;
144 
145 	/* Check if sufficient pmic info is available for this vdd */
146 	if (!voltdm->pmic) {
147 		pr_err("%s: Insufficient pmic info to scale the vdd_%s\n",
148 			__func__, voltdm->name);
149 		return -EINVAL;
150 	}
151 
152 	if (!voltdm->pmic->uv_to_vsel) {
153 		pr_err("%s: PMIC function to convert voltage in uV to vsel not registered. Hence unable to scale voltage for vdd_%s\n",
154 		       __func__, voltdm->name);
155 		return -ENODATA;
156 	}
157 
158 	if (!voltdm->read || !voltdm->write) {
159 		pr_err("%s: No read/write API for accessing vdd_%s regs\n",
160 			__func__, voltdm->name);
161 		return -EINVAL;
162 	}
163 
164 	*target_vsel = voltdm->pmic->uv_to_vsel(target_volt);
165 	*current_vsel = voltdm->pmic->uv_to_vsel(voltdm->nominal_volt);
166 
167 	/* Setting the ON voltage to the new target voltage */
168 	vc_cmdval = voltdm->read(vc->cmdval_reg);
169 	vc_cmdval &= ~vc->common->cmd_on_mask;
170 	vc_cmdval |= (*target_vsel << vc->common->cmd_on_shift);
171 	voltdm->write(vc_cmdval, vc->cmdval_reg);
172 
173 	voltdm->vc_param->on = target_volt;
174 
175 	omap_vp_update_errorgain(voltdm, target_volt);
176 
177 	return 0;
178 }
179 
180 void omap_vc_post_scale(struct voltagedomain *voltdm,
181 			unsigned long target_volt,
182 			u8 target_vsel, u8 current_vsel)
183 {
184 	u32 smps_steps = 0, smps_delay = 0;
185 
186 	smps_steps = abs(target_vsel - current_vsel);
187 	/* SMPS slew rate / step size. 2us added as buffer. */
188 	smps_delay = ((smps_steps * voltdm->pmic->step_size) /
189 			voltdm->pmic->slew_rate) + 2;
190 	udelay(smps_delay);
191 }
192 
193 /* vc_bypass_scale - VC bypass method of voltage scaling */
194 int omap_vc_bypass_scale(struct voltagedomain *voltdm,
195 			 unsigned long target_volt)
196 {
197 	struct omap_vc_channel *vc = voltdm->vc;
198 	u32 loop_cnt = 0, retries_cnt = 0;
199 	u32 vc_valid, vc_bypass_val_reg, vc_bypass_value;
200 	u8 target_vsel, current_vsel;
201 	int ret;
202 
203 	ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, &current_vsel);
204 	if (ret)
205 		return ret;
206 
207 	vc_valid = vc->common->valid;
208 	vc_bypass_val_reg = vc->common->bypass_val_reg;
209 	vc_bypass_value = (target_vsel << vc->common->data_shift) |
210 		(vc->volt_reg_addr << vc->common->regaddr_shift) |
211 		(vc->i2c_slave_addr << vc->common->slaveaddr_shift);
212 
213 	voltdm->write(vc_bypass_value, vc_bypass_val_reg);
214 	voltdm->write(vc_bypass_value | vc_valid, vc_bypass_val_reg);
215 
216 	vc_bypass_value = voltdm->read(vc_bypass_val_reg);
217 	/*
218 	 * Loop till the bypass command is acknowledged from the SMPS.
219 	 * NOTE: This is legacy code. The loop count and retry count needs
220 	 * to be revisited.
221 	 */
222 	while (!(vc_bypass_value & vc_valid)) {
223 		loop_cnt++;
224 
225 		if (retries_cnt > 10) {
226 			pr_warn("%s: Retry count exceeded\n", __func__);
227 			return -ETIMEDOUT;
228 		}
229 
230 		if (loop_cnt > 50) {
231 			retries_cnt++;
232 			loop_cnt = 0;
233 			udelay(10);
234 		}
235 		vc_bypass_value = voltdm->read(vc_bypass_val_reg);
236 	}
237 
238 	omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
239 	return 0;
240 }
241 
242 /* Convert microsecond value to number of 32kHz clock cycles */
243 static inline u32 omap_usec_to_32k(u32 usec)
244 {
245 	return DIV_ROUND_UP_ULL(32768ULL * (u64)usec, 1000000ULL);
246 }
247 
248 struct omap3_vc_timings {
249 	u32 voltsetup1;
250 	u32 voltsetup2;
251 };
252 
253 struct omap3_vc {
254 	struct voltagedomain *vd;
255 	u32 voltctrl;
256 	u32 voltsetup1;
257 	u32 voltsetup2;
258 	struct omap3_vc_timings timings[2];
259 };
260 static struct omap3_vc vc;
261 
262 void omap3_vc_set_pmic_signaling(int core_next_state)
263 {
264 	struct voltagedomain *vd = vc.vd;
265 	struct omap3_vc_timings *c = vc.timings;
266 	u32 voltctrl, voltsetup1, voltsetup2;
267 
268 	voltctrl = vc.voltctrl;
269 	voltsetup1 = vc.voltsetup1;
270 	voltsetup2 = vc.voltsetup2;
271 
272 	switch (core_next_state) {
273 	case PWRDM_POWER_OFF:
274 		voltctrl &= ~(OMAP3430_PRM_VOLTCTRL_AUTO_RET |
275 			      OMAP3430_PRM_VOLTCTRL_AUTO_SLEEP);
276 		voltctrl |= OMAP3430_PRM_VOLTCTRL_AUTO_OFF;
277 		if (voltctrl & OMAP3430_PRM_VOLTCTRL_SEL_OFF)
278 			voltsetup2 = c->voltsetup2;
279 		else
280 			voltsetup1 = c->voltsetup1;
281 		break;
282 	case PWRDM_POWER_RET:
283 	default:
284 		c++;
285 		voltctrl &= ~(OMAP3430_PRM_VOLTCTRL_AUTO_OFF |
286 			      OMAP3430_PRM_VOLTCTRL_AUTO_SLEEP);
287 		voltctrl |= OMAP3430_PRM_VOLTCTRL_AUTO_RET;
288 		voltsetup1 = c->voltsetup1;
289 		break;
290 	}
291 
292 	if (voltctrl != vc.voltctrl) {
293 		vd->write(voltctrl, OMAP3_PRM_VOLTCTRL_OFFSET);
294 		vc.voltctrl = voltctrl;
295 	}
296 	if (voltsetup1 != vc.voltsetup1) {
297 		vd->write(c->voltsetup1,
298 			  OMAP3_PRM_VOLTSETUP1_OFFSET);
299 		vc.voltsetup1 = voltsetup1;
300 	}
301 	if (voltsetup2 != vc.voltsetup2) {
302 		vd->write(c->voltsetup2,
303 			  OMAP3_PRM_VOLTSETUP2_OFFSET);
304 		vc.voltsetup2 = voltsetup2;
305 	}
306 }
307 
308 void omap4_vc_set_pmic_signaling(int core_next_state)
309 {
310 	struct voltagedomain *vd = vc.vd;
311 	u32 val;
312 
313 	if (!vd)
314 		return;
315 
316 	switch (core_next_state) {
317 	case PWRDM_POWER_RET:
318 		val = OMAP4_VDD_RET_VAL;
319 		break;
320 	default:
321 		val = OMAP4_VDD_DEFAULT_VAL;
322 		break;
323 	}
324 
325 	vd->write(val, OMAP4_PRM_VOLTCTRL_OFFSET);
326 }
327 
328 /*
329  * Configure signal polarity for sys_clkreq and sys_off_mode pins
330  * as the default values are wrong and can cause the system to hang
331  * if any twl4030 scripts are loaded.
332  */
333 static void __init omap3_vc_init_pmic_signaling(struct voltagedomain *voltdm)
334 {
335 	u32 val;
336 
337 	if (vc.vd)
338 		return;
339 
340 	vc.vd = voltdm;
341 
342 	val = voltdm->read(OMAP3_PRM_POLCTRL_OFFSET);
343 	if (!(val & OMAP3430_PRM_POLCTRL_CLKREQ_POL) ||
344 	    (val & OMAP3430_PRM_POLCTRL_OFFMODE_POL)) {
345 		val |= OMAP3430_PRM_POLCTRL_CLKREQ_POL;
346 		val &= ~OMAP3430_PRM_POLCTRL_OFFMODE_POL;
347 		pr_debug("PM: fixing sys_clkreq and sys_off_mode polarity to 0x%x\n",
348 			 val);
349 		voltdm->write(val, OMAP3_PRM_POLCTRL_OFFSET);
350 	}
351 
352 	/*
353 	 * By default let's use I2C4 signaling for retention idle
354 	 * and sys_off_mode pin signaling for off idle. This way we
355 	 * have sys_clk_req pin go down for retention and both
356 	 * sys_clk_req and sys_off_mode pins will go down for off
357 	 * idle. And we can also scale voltages to zero for off-idle.
358 	 * Note that no actual voltage scaling during off-idle will
359 	 * happen unless the board specific twl4030 PMIC scripts are
360 	 * loaded. See also omap_vc_i2c_init for comments regarding
361 	 * erratum i531.
362 	 */
363 	val = voltdm->read(OMAP3_PRM_VOLTCTRL_OFFSET);
364 	if (!(val & OMAP3430_PRM_VOLTCTRL_SEL_OFF)) {
365 		val |= OMAP3430_PRM_VOLTCTRL_SEL_OFF;
366 		pr_debug("PM: setting voltctrl sys_off_mode signaling to 0x%x\n",
367 			 val);
368 		voltdm->write(val, OMAP3_PRM_VOLTCTRL_OFFSET);
369 	}
370 	vc.voltctrl = val;
371 
372 	omap3_vc_set_pmic_signaling(PWRDM_POWER_ON);
373 }
374 
375 static void omap3_init_voltsetup1(struct voltagedomain *voltdm,
376 				  struct omap3_vc_timings *c, u32 idle)
377 {
378 	unsigned long val;
379 
380 	val = (voltdm->vc_param->on - idle) / voltdm->pmic->slew_rate;
381 	val *= voltdm->sys_clk.rate / 8 / 1000000 + 1;
382 	val <<= __ffs(voltdm->vfsm->voltsetup_mask);
383 	c->voltsetup1 &= ~voltdm->vfsm->voltsetup_mask;
384 	c->voltsetup1 |= val;
385 }
386 
387 /**
388  * omap3_set_i2c_timings - sets i2c sleep timings for a channel
389  * @voltdm: channel to configure
390  * @off_mode: select whether retention or off mode values used
391  *
392  * Calculates and sets up voltage controller to use I2C based
393  * voltage scaling for sleep modes. This can be used for either off mode
394  * or retention. Off mode has additionally an option to use sys_off_mode
395  * pad, which uses a global signal to program the whole power IC to
396  * off-mode.
397  *
398  * Note that pmic is not controlling the voltage scaling during
399  * retention signaled over I2C4, so we can keep voltsetup2 as 0.
400  * And the oscillator is not shut off over I2C4, so no need to
401  * set clksetup.
402  */
403 static void omap3_set_i2c_timings(struct voltagedomain *voltdm)
404 {
405 	struct omap3_vc_timings *c = vc.timings;
406 
407 	/* Configure PRWDM_POWER_OFF over I2C4 */
408 	omap3_init_voltsetup1(voltdm, c, voltdm->vc_param->off);
409 	c++;
410 	/* Configure PRWDM_POWER_RET over I2C4 */
411 	omap3_init_voltsetup1(voltdm, c, voltdm->vc_param->ret);
412 }
413 
414 /**
415  * omap3_set_off_timings - sets off-mode timings for a channel
416  * @voltdm: channel to configure
417  *
418  * Calculates and sets up off-mode timings for a channel. Off-mode
419  * can use either I2C based voltage scaling, or alternatively
420  * sys_off_mode pad can be used to send a global command to power IC.n,
421  * sys_off_mode has the additional benefit that voltages can be
422  * scaled to zero volt level with TWL4030 / TWL5030, I2C can only
423  * scale to 600mV.
424  *
425  * Note that omap is not controlling the voltage scaling during
426  * off idle signaled by sys_off_mode, so we can keep voltsetup1
427  * as 0.
428  */
429 static void omap3_set_off_timings(struct voltagedomain *voltdm)
430 {
431 	struct omap3_vc_timings *c = vc.timings;
432 	u32 tstart, tshut, clksetup, voltoffset;
433 
434 	if (c->voltsetup2)
435 		return;
436 
437 	omap_pm_get_oscillator(&tstart, &tshut);
438 	if (tstart == ULONG_MAX) {
439 		pr_debug("PM: oscillator start-up time not initialized, using 10ms\n");
440 		clksetup = omap_usec_to_32k(10000);
441 	} else {
442 		clksetup = omap_usec_to_32k(tstart);
443 	}
444 
445 	/*
446 	 * For twl4030 errata 27, we need to allow minimum ~488.32 us wait to
447 	 * switch from HFCLKIN to internal oscillator. That means timings
448 	 * have voltoffset fixed to 0xa in rounded up 32 KiHz cycles. And
449 	 * that means we can calculate the value based on the oscillator
450 	 * start-up time since voltoffset2 = clksetup - voltoffset.
451 	 */
452 	voltoffset = omap_usec_to_32k(488);
453 	c->voltsetup2 = clksetup - voltoffset;
454 	voltdm->write(clksetup, OMAP3_PRM_CLKSETUP_OFFSET);
455 	voltdm->write(voltoffset, OMAP3_PRM_VOLTOFFSET_OFFSET);
456 }
457 
458 static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
459 {
460 	omap3_vc_init_pmic_signaling(voltdm);
461 	omap3_set_off_timings(voltdm);
462 	omap3_set_i2c_timings(voltdm);
463 }
464 
465 /**
466  * omap4_calc_volt_ramp - calculates voltage ramping delays on omap4
467  * @voltdm: channel to calculate values for
468  * @voltage_diff: voltage difference in microvolts
469  *
470  * Calculates voltage ramp prescaler + counter values for a voltage
471  * difference on omap4. Returns a field value suitable for writing to
472  * VOLTSETUP register for a channel in following format:
473  * bits[8:9] prescaler ... bits[0:5] counter. See OMAP4 TRM for reference.
474  */
475 static u32 omap4_calc_volt_ramp(struct voltagedomain *voltdm, u32 voltage_diff)
476 {
477 	u32 prescaler;
478 	u32 cycles;
479 	u32 time;
480 
481 	time = voltage_diff / voltdm->pmic->slew_rate;
482 
483 	cycles = voltdm->sys_clk.rate / 1000 * time / 1000;
484 
485 	cycles /= 64;
486 	prescaler = 0;
487 
488 	/* shift to next prescaler until no overflow */
489 
490 	/* scale for div 256 = 64 * 4 */
491 	if (cycles > 63) {
492 		cycles /= 4;
493 		prescaler++;
494 	}
495 
496 	/* scale for div 512 = 256 * 2 */
497 	if (cycles > 63) {
498 		cycles /= 2;
499 		prescaler++;
500 	}
501 
502 	/* scale for div 2048 = 512 * 4 */
503 	if (cycles > 63) {
504 		cycles /= 4;
505 		prescaler++;
506 	}
507 
508 	/* check for overflow => invalid ramp time */
509 	if (cycles > 63) {
510 		pr_warn("%s: invalid setuptime for vdd_%s\n", __func__,
511 			voltdm->name);
512 		return 0;
513 	}
514 
515 	cycles++;
516 
517 	return (prescaler << OMAP4430_RAMP_UP_PRESCAL_SHIFT) |
518 		(cycles << OMAP4430_RAMP_UP_COUNT_SHIFT);
519 }
520 
521 /**
522  * omap4_usec_to_val_scrm - convert microsecond value to SCRM module bitfield
523  * @usec: microseconds
524  * @shift: number of bits to shift left
525  * @mask: bitfield mask
526  *
527  * Converts microsecond value to OMAP4 SCRM bitfield. Bitfield is
528  * shifted to requested position, and checked agains the mask value.
529  * If larger, forced to the max value of the field (i.e. the mask itself.)
530  * Returns the SCRM bitfield value.
531  */
532 static u32 omap4_usec_to_val_scrm(u32 usec, int shift, u32 mask)
533 {
534 	u32 val;
535 
536 	val = omap_usec_to_32k(usec) << shift;
537 
538 	/* Check for overflow, if yes, force to max value */
539 	if (val > mask)
540 		val = mask;
541 
542 	return val;
543 }
544 
545 /**
546  * omap4_set_timings - set voltage ramp timings for a channel
547  * @voltdm: channel to configure
548  * @off_mode: whether off-mode values are used
549  *
550  * Calculates and sets the voltage ramp up / down values for a channel.
551  */
552 static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
553 {
554 	u32 val;
555 	u32 ramp;
556 	int offset;
557 	u32 tstart, tshut;
558 
559 	if (off_mode) {
560 		ramp = omap4_calc_volt_ramp(voltdm,
561 			voltdm->vc_param->on - voltdm->vc_param->off);
562 		offset = voltdm->vfsm->voltsetup_off_reg;
563 	} else {
564 		ramp = omap4_calc_volt_ramp(voltdm,
565 			voltdm->vc_param->on - voltdm->vc_param->ret);
566 		offset = voltdm->vfsm->voltsetup_reg;
567 	}
568 
569 	if (!ramp)
570 		return;
571 
572 	val = voltdm->read(offset);
573 
574 	val |= ramp << OMAP4430_RAMP_DOWN_COUNT_SHIFT;
575 
576 	val |= ramp << OMAP4430_RAMP_UP_COUNT_SHIFT;
577 
578 	voltdm->write(val, offset);
579 
580 	omap_pm_get_oscillator(&tstart, &tshut);
581 
582 	val = omap4_usec_to_val_scrm(tstart, OMAP4_SETUPTIME_SHIFT,
583 		OMAP4_SETUPTIME_MASK);
584 	val |= omap4_usec_to_val_scrm(tshut, OMAP4_DOWNTIME_SHIFT,
585 		OMAP4_DOWNTIME_MASK);
586 
587 	writel_relaxed(val, OMAP4_SCRM_CLKSETUPTIME);
588 }
589 
590 static void __init omap4_vc_init_pmic_signaling(struct voltagedomain *voltdm)
591 {
592 	if (vc.vd)
593 		return;
594 
595 	vc.vd = voltdm;
596 	voltdm->write(OMAP4_VDD_DEFAULT_VAL, OMAP4_PRM_VOLTCTRL_OFFSET);
597 }
598 
599 /* OMAP4 specific voltage init functions */
600 static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
601 {
602 	omap4_vc_init_pmic_signaling(voltdm);
603 	omap4_set_timings(voltdm, true);
604 	omap4_set_timings(voltdm, false);
605 }
606 
607 struct i2c_init_data {
608 	u8 loadbits;
609 	u8 load;
610 	u8 hsscll_38_4;
611 	u8 hsscll_26;
612 	u8 hsscll_19_2;
613 	u8 hsscll_16_8;
614 	u8 hsscll_12;
615 };
616 
617 static const struct i2c_init_data omap4_i2c_timing_data[] __initconst = {
618 	{
619 		.load = 50,
620 		.loadbits = 0x3,
621 		.hsscll_38_4 = 13,
622 		.hsscll_26 = 11,
623 		.hsscll_19_2 = 9,
624 		.hsscll_16_8 = 9,
625 		.hsscll_12 = 8,
626 	},
627 	{
628 		.load = 25,
629 		.loadbits = 0x2,
630 		.hsscll_38_4 = 13,
631 		.hsscll_26 = 11,
632 		.hsscll_19_2 = 9,
633 		.hsscll_16_8 = 9,
634 		.hsscll_12 = 8,
635 	},
636 	{
637 		.load = 12,
638 		.loadbits = 0x1,
639 		.hsscll_38_4 = 11,
640 		.hsscll_26 = 10,
641 		.hsscll_19_2 = 9,
642 		.hsscll_16_8 = 9,
643 		.hsscll_12 = 8,
644 	},
645 	{
646 		.load = 0,
647 		.loadbits = 0x0,
648 		.hsscll_38_4 = 12,
649 		.hsscll_26 = 10,
650 		.hsscll_19_2 = 9,
651 		.hsscll_16_8 = 8,
652 		.hsscll_12 = 8,
653 	},
654 };
655 
656 /**
657  * omap4_vc_i2c_timing_init - sets up board I2C timing parameters
658  * @voltdm: voltagedomain pointer to get data from
659  *
660  * Use PMIC + board supplied settings for calculating the total I2C
661  * channel capacitance and set the timing parameters based on this.
662  * Pre-calculated values are provided in data tables, as it is not
663  * too straightforward to calculate these runtime.
664  */
665 static void __init omap4_vc_i2c_timing_init(struct voltagedomain *voltdm)
666 {
667 	u32 capacitance;
668 	u32 val;
669 	u16 hsscll;
670 	const struct i2c_init_data *i2c_data;
671 
672 	if (!voltdm->pmic->i2c_high_speed) {
673 		pr_info("%s: using bootloader low-speed timings\n", __func__);
674 		return;
675 	}
676 
677 	/* PCB trace capacitance, 0.125pF / mm => mm / 8 */
678 	capacitance = DIV_ROUND_UP(sr_i2c_pcb_length, 8);
679 
680 	/* OMAP pad capacitance */
681 	capacitance += 4;
682 
683 	/* PMIC pad capacitance */
684 	capacitance += voltdm->pmic->i2c_pad_load;
685 
686 	/* Search for capacitance match in the table */
687 	i2c_data = omap4_i2c_timing_data;
688 
689 	while (i2c_data->load > capacitance)
690 		i2c_data++;
691 
692 	/* Select proper values based on sysclk frequency */
693 	switch (voltdm->sys_clk.rate) {
694 	case 38400000:
695 		hsscll = i2c_data->hsscll_38_4;
696 		break;
697 	case 26000000:
698 		hsscll = i2c_data->hsscll_26;
699 		break;
700 	case 19200000:
701 		hsscll = i2c_data->hsscll_19_2;
702 		break;
703 	case 16800000:
704 		hsscll = i2c_data->hsscll_16_8;
705 		break;
706 	case 12000000:
707 		hsscll = i2c_data->hsscll_12;
708 		break;
709 	default:
710 		pr_warn("%s: unsupported sysclk rate: %d!\n", __func__,
711 			voltdm->sys_clk.rate);
712 		return;
713 	}
714 
715 	/* Loadbits define pull setup for the I2C channels */
716 	val = i2c_data->loadbits << 25 | i2c_data->loadbits << 29;
717 
718 	/* Write to SYSCTRL_PADCONF_WKUP_CTRL_I2C_2 to setup I2C pull */
719 	writel_relaxed(val, OMAP2_L4_IO_ADDRESS(OMAP4_CTRL_MODULE_PAD_WKUP +
720 				OMAP4_CTRL_MODULE_PAD_WKUP_CONTROL_I2C_2));
721 
722 	/* HSSCLH can always be zero */
723 	val = hsscll << OMAP4430_HSSCLL_SHIFT;
724 	val |= (0x28 << OMAP4430_SCLL_SHIFT | 0x2c << OMAP4430_SCLH_SHIFT);
725 
726 	/* Write setup times to I2C config register */
727 	voltdm->write(val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
728 }
729 
730 
731 
732 /**
733  * omap_vc_i2c_init - initialize I2C interface to PMIC
734  * @voltdm: voltage domain containing VC data
735  *
736  * Use PMIC supplied settings for I2C high-speed mode and
737  * master code (if set) and program the VC I2C configuration
738  * register.
739  *
740  * The VC I2C configuration is common to all VC channels,
741  * so this function only configures I2C for the first VC
742  * channel registers.  All other VC channels will use the
743  * same configuration.
744  */
745 static void __init omap_vc_i2c_init(struct voltagedomain *voltdm)
746 {
747 	struct omap_vc_channel *vc = voltdm->vc;
748 	static bool initialized;
749 	static bool i2c_high_speed;
750 	u8 mcode;
751 
752 	if (initialized) {
753 		if (voltdm->pmic->i2c_high_speed != i2c_high_speed)
754 			pr_warn("%s: I2C config for vdd_%s does not match other channels (%u).\n",
755 				__func__, voltdm->name, i2c_high_speed);
756 		return;
757 	}
758 
759 	/*
760 	 * Note that for omap3 OMAP3430_SREN_MASK clears SREN to work around
761 	 * erratum i531 "Extra Power Consumed When Repeated Start Operation
762 	 * Mode Is Enabled on I2C Interface Dedicated for Smart Reflex (I2C4)".
763 	 * Otherwise I2C4 eventually leads into about 23mW extra power being
764 	 * consumed even during off idle using VMODE.
765 	 */
766 	i2c_high_speed = voltdm->pmic->i2c_high_speed;
767 	if (i2c_high_speed)
768 		voltdm->rmw(vc->common->i2c_cfg_clear_mask,
769 			    vc->common->i2c_cfg_hsen_mask,
770 			    vc->common->i2c_cfg_reg);
771 
772 	mcode = voltdm->pmic->i2c_mcode;
773 	if (mcode)
774 		voltdm->rmw(vc->common->i2c_mcode_mask,
775 			    mcode << __ffs(vc->common->i2c_mcode_mask),
776 			    vc->common->i2c_cfg_reg);
777 
778 	if (cpu_is_omap44xx())
779 		omap4_vc_i2c_timing_init(voltdm);
780 
781 	initialized = true;
782 }
783 
784 /**
785  * omap_vc_calc_vsel - calculate vsel value for a channel
786  * @voltdm: channel to calculate value for
787  * @uvolt: microvolt value to convert to vsel
788  *
789  * Converts a microvolt value to vsel value for the used PMIC.
790  * This checks whether the microvolt value is out of bounds, and
791  * adjusts the value accordingly. If unsupported value detected,
792  * warning is thrown.
793  */
794 static u8 omap_vc_calc_vsel(struct voltagedomain *voltdm, u32 uvolt)
795 {
796 	if (voltdm->pmic->vddmin > uvolt)
797 		uvolt = voltdm->pmic->vddmin;
798 	if (voltdm->pmic->vddmax < uvolt) {
799 		WARN(1, "%s: voltage not supported by pmic: %u vs max %u\n",
800 			__func__, uvolt, voltdm->pmic->vddmax);
801 		/* Lets try maximum value anyway */
802 		uvolt = voltdm->pmic->vddmax;
803 	}
804 
805 	return voltdm->pmic->uv_to_vsel(uvolt);
806 }
807 
808 #ifdef CONFIG_PM
809 /**
810  * omap_pm_setup_sr_i2c_pcb_length - set length of SR I2C traces on PCB
811  * @mm: length of the PCB trace in millimetres
812  *
813  * Sets the PCB trace length for the I2C channel. By default uses 63mm.
814  * This is needed for properly calculating the capacitance value for
815  * the PCB trace, and for setting the SR I2C channel timing parameters.
816  */
817 void __init omap_pm_setup_sr_i2c_pcb_length(u32 mm)
818 {
819 	sr_i2c_pcb_length = mm;
820 }
821 #endif
822 
823 void __init omap_vc_init_channel(struct voltagedomain *voltdm)
824 {
825 	struct omap_vc_channel *vc = voltdm->vc;
826 	u8 on_vsel, onlp_vsel, ret_vsel, off_vsel;
827 	u32 val;
828 
829 	if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
830 		pr_err("%s: No PMIC info for vdd_%s\n", __func__, voltdm->name);
831 		return;
832 	}
833 
834 	if (!voltdm->read || !voltdm->write) {
835 		pr_err("%s: No read/write API for accessing vdd_%s regs\n",
836 			__func__, voltdm->name);
837 		return;
838 	}
839 
840 	vc->cfg_channel = 0;
841 	if (vc->flags & OMAP_VC_CHANNEL_CFG_MUTANT)
842 		vc_cfg_bits = &vc_mutant_channel_cfg;
843 	else
844 		vc_cfg_bits = &vc_default_channel_cfg;
845 
846 	/* get PMIC/board specific settings */
847 	vc->i2c_slave_addr = voltdm->pmic->i2c_slave_addr;
848 	vc->volt_reg_addr = voltdm->pmic->volt_reg_addr;
849 	vc->cmd_reg_addr = voltdm->pmic->cmd_reg_addr;
850 
851 	/* Configure the i2c slave address for this VC */
852 	voltdm->rmw(vc->smps_sa_mask,
853 		    vc->i2c_slave_addr << __ffs(vc->smps_sa_mask),
854 		    vc->smps_sa_reg);
855 	vc->cfg_channel |= vc_cfg_bits->sa;
856 
857 	/*
858 	 * Configure the PMIC register addresses.
859 	 */
860 	voltdm->rmw(vc->smps_volra_mask,
861 		    vc->volt_reg_addr << __ffs(vc->smps_volra_mask),
862 		    vc->smps_volra_reg);
863 	vc->cfg_channel |= vc_cfg_bits->rav;
864 
865 	if (vc->cmd_reg_addr) {
866 		voltdm->rmw(vc->smps_cmdra_mask,
867 			    vc->cmd_reg_addr << __ffs(vc->smps_cmdra_mask),
868 			    vc->smps_cmdra_reg);
869 		vc->cfg_channel |= vc_cfg_bits->rac;
870 	}
871 
872 	if (vc->cmd_reg_addr == vc->volt_reg_addr)
873 		vc->cfg_channel |= vc_cfg_bits->racen;
874 
875 	/* Set up the on, inactive, retention and off voltage */
876 	on_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->on);
877 	onlp_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->onlp);
878 	ret_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->ret);
879 	off_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->off);
880 
881 	val = ((on_vsel << vc->common->cmd_on_shift) |
882 	       (onlp_vsel << vc->common->cmd_onlp_shift) |
883 	       (ret_vsel << vc->common->cmd_ret_shift) |
884 	       (off_vsel << vc->common->cmd_off_shift));
885 	voltdm->write(val, vc->cmdval_reg);
886 	vc->cfg_channel |= vc_cfg_bits->cmd;
887 
888 	/* Channel configuration */
889 	omap_vc_config_channel(voltdm);
890 
891 	omap_vc_i2c_init(voltdm);
892 
893 	if (cpu_is_omap34xx())
894 		omap3_vc_init_channel(voltdm);
895 	else if (cpu_is_omap44xx())
896 		omap4_vc_init_channel(voltdm);
897 }
898 
899