2 * OMAP Voltage Controller (VC) interface
4 * Copyright (C) 2011 Texas Instruments, Inc.
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.
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/bug.h>
16 #include <asm/div64.h>
22 #include "prm-regbits-34xx.h"
23 #include "prm-regbits-44xx.h"
30 * struct omap_vc_channel_cfg - describe the cfg_channel bitfield
31 * @sa: bit for slave address
32 * @rav: bit for voltage configuration register
33 * @rac: bit for command configuration register
34 * @racen: enable bit for RAC
35 * @cmd: bit for command value set selection
37 * Channel configuration bits, common for OMAP3+
38 * OMAP3 register: PRM_VC_CH_CONF
39 * OMAP4 register: PRM_VC_CFG_CHANNEL
40 * OMAP5 register: PRM_VC_SMPS_<voltdm>_CONFIG
42 struct omap_vc_channel_cfg
{
50 static struct omap_vc_channel_cfg vc_default_channel_cfg
= {
59 * On OMAP3+, all VC channels have the above default bitfield
60 * configuration, except the OMAP4 MPU channel. This appears
61 * to be a freak accident as every other VC channel has the
62 * default configuration, thus creating a mutant channel config.
64 static struct omap_vc_channel_cfg vc_mutant_channel_cfg
= {
72 static struct omap_vc_channel_cfg
*vc_cfg_bits
;
74 /* Default I2C trace length on pcb, 6.3cm. Used for capacitance calculations. */
75 static u32 sr_i2c_pcb_length
= 63;
76 #define CFG_CHANNEL_MASK 0x1f
79 * omap_vc_config_channel - configure VC channel to PMIC mappings
80 * @voltdm: pointer to voltagdomain defining the desired VC channel
82 * Configures the VC channel to PMIC mappings for the following
84 * - i2c slave address (SA)
85 * - voltage configuration address (RAV)
86 * - command configuration address (RAC) and enable bit (RACEN)
87 * - command values for ON, ONLP, RET and OFF (CMD)
89 * This function currently only allows flexible configuration of the
90 * non-default channel. Starting with OMAP4, there are more than 2
91 * channels, with one defined as the default (on OMAP4, it's MPU.)
92 * Only the non-default channel can be configured.
94 static int omap_vc_config_channel(struct voltagedomain
*voltdm
)
96 struct omap_vc_channel
*vc
= voltdm
->vc
;
99 * For default channel, the only configurable bit is RACEN.
100 * All others must stay at zero (see function comment above.)
102 if (vc
->flags
& OMAP_VC_CHANNEL_DEFAULT
)
103 vc
->cfg_channel
&= vc_cfg_bits
->racen
;
105 voltdm
->rmw(CFG_CHANNEL_MASK
<< vc
->cfg_channel_sa_shift
,
106 vc
->cfg_channel
<< vc
->cfg_channel_sa_shift
,
107 vc
->cfg_channel_reg
);
112 /* Voltage scale and accessory APIs */
113 int omap_vc_pre_scale(struct voltagedomain
*voltdm
,
114 unsigned long target_volt
,
115 u8
*target_vsel
, u8
*current_vsel
)
117 struct omap_vc_channel
*vc
= voltdm
->vc
;
120 /* Check if sufficient pmic info is available for this vdd */
122 pr_err("%s: Insufficient pmic info to scale the vdd_%s\n",
123 __func__
, voltdm
->name
);
127 if (!voltdm
->pmic
->uv_to_vsel
) {
128 pr_err("%s: PMIC function to convert voltage in uV to vsel not registered. Hence unable to scale voltage for vdd_%s\n",
129 __func__
, voltdm
->name
);
133 if (!voltdm
->read
|| !voltdm
->write
) {
134 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
135 __func__
, voltdm
->name
);
139 *target_vsel
= voltdm
->pmic
->uv_to_vsel(target_volt
);
140 *current_vsel
= voltdm
->pmic
->uv_to_vsel(voltdm
->nominal_volt
);
142 /* Setting the ON voltage to the new target voltage */
143 vc_cmdval
= voltdm
->read(vc
->cmdval_reg
);
144 vc_cmdval
&= ~vc
->common
->cmd_on_mask
;
145 vc_cmdval
|= (*target_vsel
<< vc
->common
->cmd_on_shift
);
146 voltdm
->write(vc_cmdval
, vc
->cmdval_reg
);
148 voltdm
->vc_param
->on
= target_volt
;
150 omap_vp_update_errorgain(voltdm
, target_volt
);
155 void omap_vc_post_scale(struct voltagedomain
*voltdm
,
156 unsigned long target_volt
,
157 u8 target_vsel
, u8 current_vsel
)
159 u32 smps_steps
= 0, smps_delay
= 0;
161 smps_steps
= abs(target_vsel
- current_vsel
);
162 /* SMPS slew rate / step size. 2us added as buffer. */
163 smps_delay
= ((smps_steps
* voltdm
->pmic
->step_size
) /
164 voltdm
->pmic
->slew_rate
) + 2;
168 /* vc_bypass_scale - VC bypass method of voltage scaling */
169 int omap_vc_bypass_scale(struct voltagedomain
*voltdm
,
170 unsigned long target_volt
)
172 struct omap_vc_channel
*vc
= voltdm
->vc
;
173 u32 loop_cnt
= 0, retries_cnt
= 0;
174 u32 vc_valid
, vc_bypass_val_reg
, vc_bypass_value
;
175 u8 target_vsel
, current_vsel
;
178 ret
= omap_vc_pre_scale(voltdm
, target_volt
, &target_vsel
, ¤t_vsel
);
182 vc_valid
= vc
->common
->valid
;
183 vc_bypass_val_reg
= vc
->common
->bypass_val_reg
;
184 vc_bypass_value
= (target_vsel
<< vc
->common
->data_shift
) |
185 (vc
->volt_reg_addr
<< vc
->common
->regaddr_shift
) |
186 (vc
->i2c_slave_addr
<< vc
->common
->slaveaddr_shift
);
188 voltdm
->write(vc_bypass_value
, vc_bypass_val_reg
);
189 voltdm
->write(vc_bypass_value
| vc_valid
, vc_bypass_val_reg
);
191 vc_bypass_value
= voltdm
->read(vc_bypass_val_reg
);
193 * Loop till the bypass command is acknowledged from the SMPS.
194 * NOTE: This is legacy code. The loop count and retry count needs
197 while (!(vc_bypass_value
& vc_valid
)) {
200 if (retries_cnt
> 10) {
201 pr_warning("%s: Retry count exceeded\n", __func__
);
210 vc_bypass_value
= voltdm
->read(vc_bypass_val_reg
);
213 omap_vc_post_scale(voltdm
, target_volt
, target_vsel
, current_vsel
);
217 /* Convert microsecond value to number of 32kHz clock cycles */
218 static inline u32
omap_usec_to_32k(u32 usec
)
220 return DIV_ROUND_UP_ULL(32768ULL * (u64
)usec
, 1000000ULL);
223 /* Set oscillator setup time for omap3 */
224 static void omap3_set_clksetup(u32 usec
, struct voltagedomain
*voltdm
)
226 voltdm
->write(omap_usec_to_32k(usec
), OMAP3_PRM_CLKSETUP_OFFSET
);
230 * omap3_set_i2c_timings - sets i2c sleep timings for a channel
231 * @voltdm: channel to configure
232 * @off_mode: select whether retention or off mode values used
234 * Calculates and sets up voltage controller to use I2C based
235 * voltage scaling for sleep modes. This can be used for either off mode
236 * or retention. Off mode has additionally an option to use sys_off_mode
237 * pad, which uses a global signal to program the whole power IC to
240 static void omap3_set_i2c_timings(struct voltagedomain
*voltdm
, bool off_mode
)
242 unsigned long voltsetup1
;
246 * Oscillator is shut down only if we are using sys_off_mode pad,
247 * thus we set a minimal setup time here
249 omap3_set_clksetup(1, voltdm
);
252 tgt_volt
= voltdm
->vc_param
->off
;
254 tgt_volt
= voltdm
->vc_param
->ret
;
256 voltsetup1
= (voltdm
->vc_param
->on
- tgt_volt
) /
257 voltdm
->pmic
->slew_rate
;
259 voltsetup1
= voltsetup1
* voltdm
->sys_clk
.rate
/ 8 / 1000000 + 1;
261 voltdm
->rmw(voltdm
->vfsm
->voltsetup_mask
,
262 voltsetup1
<< __ffs(voltdm
->vfsm
->voltsetup_mask
),
263 voltdm
->vfsm
->voltsetup_reg
);
266 * pmic is not controlling the voltage scaling during retention,
267 * thus set voltsetup2 to 0
269 voltdm
->write(0, OMAP3_PRM_VOLTSETUP2_OFFSET
);
273 * omap3_set_off_timings - sets off-mode timings for a channel
274 * @voltdm: channel to configure
276 * Calculates and sets up off-mode timings for a channel. Off-mode
277 * can use either I2C based voltage scaling, or alternatively
278 * sys_off_mode pad can be used to send a global command to power IC.
279 * This function first checks which mode is being used, and calls
280 * omap3_set_i2c_timings() if the system is using I2C control mode.
281 * sys_off_mode has the additional benefit that voltages can be
282 * scaled to zero volt level with TWL4030 / TWL5030, I2C can only
285 static void omap3_set_off_timings(struct voltagedomain
*voltdm
)
287 unsigned long clksetup
;
288 unsigned long voltsetup2
;
289 unsigned long voltsetup2_old
;
293 /* check if sys_off_mode is used to control off-mode voltages */
294 val
= voltdm
->read(OMAP3_PRM_VOLTCTRL_OFFSET
);
295 if (!(val
& OMAP3430_SEL_OFF_MASK
)) {
296 /* No, omap is controlling them over I2C */
297 omap3_set_i2c_timings(voltdm
, true);
301 omap_pm_get_oscillator(&tstart
, &tshut
);
302 omap3_set_clksetup(tstart
, voltdm
);
304 clksetup
= voltdm
->read(OMAP3_PRM_CLKSETUP_OFFSET
);
306 /* voltsetup 2 in us */
307 voltsetup2
= voltdm
->vc_param
->on
/ voltdm
->pmic
->slew_rate
;
309 /* convert to 32k clk cycles */
310 voltsetup2
= DIV_ROUND_UP(voltsetup2
* 32768, 1000000);
312 voltsetup2_old
= voltdm
->read(OMAP3_PRM_VOLTSETUP2_OFFSET
);
315 * Update voltsetup2 if higher than current value (needed because
316 * we have multiple channels with different ramp times), also
317 * update voltoffset always to value recommended by TRM
319 if (voltsetup2
> voltsetup2_old
) {
320 voltdm
->write(voltsetup2
, OMAP3_PRM_VOLTSETUP2_OFFSET
);
321 voltdm
->write(clksetup
- voltsetup2
,
322 OMAP3_PRM_VOLTOFFSET_OFFSET
);
324 voltdm
->write(clksetup
- voltsetup2_old
,
325 OMAP3_PRM_VOLTOFFSET_OFFSET
);
328 * omap is not controlling voltage scaling during off-mode,
329 * thus set voltsetup1 to 0
331 voltdm
->rmw(voltdm
->vfsm
->voltsetup_mask
, 0,
332 voltdm
->vfsm
->voltsetup_reg
);
334 /* voltoffset must be clksetup minus voltsetup2 according to TRM */
335 voltdm
->write(clksetup
- voltsetup2
, OMAP3_PRM_VOLTOFFSET_OFFSET
);
338 static void __init
omap3_vc_init_channel(struct voltagedomain
*voltdm
)
340 omap3_set_off_timings(voltdm
);
344 * omap4_calc_volt_ramp - calculates voltage ramping delays on omap4
345 * @voltdm: channel to calculate values for
346 * @voltage_diff: voltage difference in microvolts
348 * Calculates voltage ramp prescaler + counter values for a voltage
349 * difference on omap4. Returns a field value suitable for writing to
350 * VOLTSETUP register for a channel in following format:
351 * bits[8:9] prescaler ... bits[0:5] counter. See OMAP4 TRM for reference.
353 static u32
omap4_calc_volt_ramp(struct voltagedomain
*voltdm
, u32 voltage_diff
)
359 time
= voltage_diff
/ voltdm
->pmic
->slew_rate
;
361 cycles
= voltdm
->sys_clk
.rate
/ 1000 * time
/ 1000;
366 /* shift to next prescaler until no overflow */
368 /* scale for div 256 = 64 * 4 */
374 /* scale for div 512 = 256 * 2 */
380 /* scale for div 2048 = 512 * 4 */
386 /* check for overflow => invalid ramp time */
388 pr_warn("%s: invalid setuptime for vdd_%s\n", __func__
,
395 return (prescaler
<< OMAP4430_RAMP_UP_PRESCAL_SHIFT
) |
396 (cycles
<< OMAP4430_RAMP_UP_COUNT_SHIFT
);
400 * omap4_usec_to_val_scrm - convert microsecond value to SCRM module bitfield
401 * @usec: microseconds
402 * @shift: number of bits to shift left
403 * @mask: bitfield mask
405 * Converts microsecond value to OMAP4 SCRM bitfield. Bitfield is
406 * shifted to requested position, and checked agains the mask value.
407 * If larger, forced to the max value of the field (i.e. the mask itself.)
408 * Returns the SCRM bitfield value.
410 static u32
omap4_usec_to_val_scrm(u32 usec
, int shift
, u32 mask
)
414 val
= omap_usec_to_32k(usec
) << shift
;
416 /* Check for overflow, if yes, force to max value */
424 * omap4_set_timings - set voltage ramp timings for a channel
425 * @voltdm: channel to configure
426 * @off_mode: whether off-mode values are used
428 * Calculates and sets the voltage ramp up / down values for a channel.
430 static void omap4_set_timings(struct voltagedomain
*voltdm
, bool off_mode
)
438 ramp
= omap4_calc_volt_ramp(voltdm
,
439 voltdm
->vc_param
->on
- voltdm
->vc_param
->off
);
440 offset
= voltdm
->vfsm
->voltsetup_off_reg
;
442 ramp
= omap4_calc_volt_ramp(voltdm
,
443 voltdm
->vc_param
->on
- voltdm
->vc_param
->ret
);
444 offset
= voltdm
->vfsm
->voltsetup_reg
;
450 val
= voltdm
->read(offset
);
452 val
|= ramp
<< OMAP4430_RAMP_DOWN_COUNT_SHIFT
;
454 val
|= ramp
<< OMAP4430_RAMP_UP_COUNT_SHIFT
;
456 voltdm
->write(val
, offset
);
458 omap_pm_get_oscillator(&tstart
, &tshut
);
460 val
= omap4_usec_to_val_scrm(tstart
, OMAP4_SETUPTIME_SHIFT
,
461 OMAP4_SETUPTIME_MASK
);
462 val
|= omap4_usec_to_val_scrm(tshut
, OMAP4_DOWNTIME_SHIFT
,
463 OMAP4_DOWNTIME_MASK
);
465 __raw_writel(val
, OMAP4_SCRM_CLKSETUPTIME
);
468 /* OMAP4 specific voltage init functions */
469 static void __init
omap4_vc_init_channel(struct voltagedomain
*voltdm
)
471 omap4_set_timings(voltdm
, true);
472 omap4_set_timings(voltdm
, false);
475 struct i2c_init_data
{
485 static const __initdata
struct i2c_init_data omap4_i2c_timing_data
[] = {
525 * omap4_vc_i2c_timing_init - sets up board I2C timing parameters
526 * @voltdm: voltagedomain pointer to get data from
528 * Use PMIC + board supplied settings for calculating the total I2C
529 * channel capacitance and set the timing parameters based on this.
530 * Pre-calculated values are provided in data tables, as it is not
531 * too straightforward to calculate these runtime.
533 static void __init
omap4_vc_i2c_timing_init(struct voltagedomain
*voltdm
)
538 const struct i2c_init_data
*i2c_data
;
540 if (!voltdm
->pmic
->i2c_high_speed
) {
541 pr_warn("%s: only high speed supported!\n", __func__
);
545 /* PCB trace capacitance, 0.125pF / mm => mm / 8 */
546 capacitance
= DIV_ROUND_UP(sr_i2c_pcb_length
, 8);
548 /* OMAP pad capacitance */
551 /* PMIC pad capacitance */
552 capacitance
+= voltdm
->pmic
->i2c_pad_load
;
554 /* Search for capacitance match in the table */
555 i2c_data
= omap4_i2c_timing_data
;
557 while (i2c_data
->load
> capacitance
)
560 /* Select proper values based on sysclk frequency */
561 switch (voltdm
->sys_clk
.rate
) {
563 hsscll
= i2c_data
->hsscll_38_4
;
566 hsscll
= i2c_data
->hsscll_26
;
569 hsscll
= i2c_data
->hsscll_19_2
;
572 hsscll
= i2c_data
->hsscll_16_8
;
575 hsscll
= i2c_data
->hsscll_12
;
578 pr_warn("%s: unsupported sysclk rate: %d!\n", __func__
,
579 voltdm
->sys_clk
.rate
);
583 /* Loadbits define pull setup for the I2C channels */
584 val
= i2c_data
->loadbits
<< 25 | i2c_data
->loadbits
<< 29;
586 /* Write to SYSCTRL_PADCONF_WKUP_CTRL_I2C_2 to setup I2C pull */
587 __raw_writel(val
, OMAP2_L4_IO_ADDRESS(OMAP4_CTRL_MODULE_PAD_WKUP
+
588 OMAP4_CTRL_MODULE_PAD_WKUP_CONTROL_I2C_2
));
590 /* HSSCLH can always be zero */
591 val
= hsscll
<< OMAP4430_HSSCLL_SHIFT
;
592 val
|= (0x28 << OMAP4430_SCLL_SHIFT
| 0x2c << OMAP4430_SCLH_SHIFT
);
594 /* Write setup times to I2C config register */
595 voltdm
->write(val
, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET
);
601 * omap_vc_i2c_init - initialize I2C interface to PMIC
602 * @voltdm: voltage domain containing VC data
604 * Use PMIC supplied settings for I2C high-speed mode and
605 * master code (if set) and program the VC I2C configuration
608 * The VC I2C configuration is common to all VC channels,
609 * so this function only configures I2C for the first VC
610 * channel registers. All other VC channels will use the
611 * same configuration.
613 static void __init
omap_vc_i2c_init(struct voltagedomain
*voltdm
)
615 struct omap_vc_channel
*vc
= voltdm
->vc
;
616 static bool initialized
;
617 static bool i2c_high_speed
;
621 if (voltdm
->pmic
->i2c_high_speed
!= i2c_high_speed
)
622 pr_warn("%s: I2C config for vdd_%s does not match other channels (%u).\n",
623 __func__
, voltdm
->name
, i2c_high_speed
);
627 i2c_high_speed
= voltdm
->pmic
->i2c_high_speed
;
629 voltdm
->rmw(vc
->common
->i2c_cfg_hsen_mask
,
630 vc
->common
->i2c_cfg_hsen_mask
,
631 vc
->common
->i2c_cfg_reg
);
633 mcode
= voltdm
->pmic
->i2c_mcode
;
635 voltdm
->rmw(vc
->common
->i2c_mcode_mask
,
636 mcode
<< __ffs(vc
->common
->i2c_mcode_mask
),
637 vc
->common
->i2c_cfg_reg
);
639 if (cpu_is_omap44xx())
640 omap4_vc_i2c_timing_init(voltdm
);
646 * omap_vc_calc_vsel - calculate vsel value for a channel
647 * @voltdm: channel to calculate value for
648 * @uvolt: microvolt value to convert to vsel
650 * Converts a microvolt value to vsel value for the used PMIC.
651 * This checks whether the microvolt value is out of bounds, and
652 * adjusts the value accordingly. If unsupported value detected,
655 static u8
omap_vc_calc_vsel(struct voltagedomain
*voltdm
, u32 uvolt
)
657 if (voltdm
->pmic
->vddmin
> uvolt
)
658 uvolt
= voltdm
->pmic
->vddmin
;
659 if (voltdm
->pmic
->vddmax
< uvolt
) {
660 WARN(1, "%s: voltage not supported by pmic: %u vs max %u\n",
661 __func__
, uvolt
, voltdm
->pmic
->vddmax
);
662 /* Lets try maximum value anyway */
663 uvolt
= voltdm
->pmic
->vddmax
;
666 return voltdm
->pmic
->uv_to_vsel(uvolt
);
671 * omap_pm_setup_sr_i2c_pcb_length - set length of SR I2C traces on PCB
672 * @mm: length of the PCB trace in millimetres
674 * Sets the PCB trace length for the I2C channel. By default uses 63mm.
675 * This is needed for properly calculating the capacitance value for
676 * the PCB trace, and for setting the SR I2C channel timing parameters.
678 void __init
omap_pm_setup_sr_i2c_pcb_length(u32 mm
)
680 sr_i2c_pcb_length
= mm
;
684 void __init
omap_vc_init_channel(struct voltagedomain
*voltdm
)
686 struct omap_vc_channel
*vc
= voltdm
->vc
;
687 u8 on_vsel
, onlp_vsel
, ret_vsel
, off_vsel
;
690 if (!voltdm
->pmic
|| !voltdm
->pmic
->uv_to_vsel
) {
691 pr_err("%s: No PMIC info for vdd_%s\n", __func__
, voltdm
->name
);
695 if (!voltdm
->read
|| !voltdm
->write
) {
696 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
697 __func__
, voltdm
->name
);
702 if (vc
->flags
& OMAP_VC_CHANNEL_CFG_MUTANT
)
703 vc_cfg_bits
= &vc_mutant_channel_cfg
;
705 vc_cfg_bits
= &vc_default_channel_cfg
;
707 /* get PMIC/board specific settings */
708 vc
->i2c_slave_addr
= voltdm
->pmic
->i2c_slave_addr
;
709 vc
->volt_reg_addr
= voltdm
->pmic
->volt_reg_addr
;
710 vc
->cmd_reg_addr
= voltdm
->pmic
->cmd_reg_addr
;
712 /* Configure the i2c slave address for this VC */
713 voltdm
->rmw(vc
->smps_sa_mask
,
714 vc
->i2c_slave_addr
<< __ffs(vc
->smps_sa_mask
),
716 vc
->cfg_channel
|= vc_cfg_bits
->sa
;
719 * Configure the PMIC register addresses.
721 voltdm
->rmw(vc
->smps_volra_mask
,
722 vc
->volt_reg_addr
<< __ffs(vc
->smps_volra_mask
),
724 vc
->cfg_channel
|= vc_cfg_bits
->rav
;
726 if (vc
->cmd_reg_addr
) {
727 voltdm
->rmw(vc
->smps_cmdra_mask
,
728 vc
->cmd_reg_addr
<< __ffs(vc
->smps_cmdra_mask
),
730 vc
->cfg_channel
|= vc_cfg_bits
->rac
;
733 if (vc
->cmd_reg_addr
== vc
->volt_reg_addr
)
734 vc
->cfg_channel
|= vc_cfg_bits
->racen
;
736 /* Set up the on, inactive, retention and off voltage */
737 on_vsel
= omap_vc_calc_vsel(voltdm
, voltdm
->vc_param
->on
);
738 onlp_vsel
= omap_vc_calc_vsel(voltdm
, voltdm
->vc_param
->onlp
);
739 ret_vsel
= omap_vc_calc_vsel(voltdm
, voltdm
->vc_param
->ret
);
740 off_vsel
= omap_vc_calc_vsel(voltdm
, voltdm
->vc_param
->off
);
742 val
= ((on_vsel
<< vc
->common
->cmd_on_shift
) |
743 (onlp_vsel
<< vc
->common
->cmd_onlp_shift
) |
744 (ret_vsel
<< vc
->common
->cmd_ret_shift
) |
745 (off_vsel
<< vc
->common
->cmd_off_shift
));
746 voltdm
->write(val
, vc
->cmdval_reg
);
747 vc
->cfg_channel
|= vc_cfg_bits
->cmd
;
749 /* Channel configuration */
750 omap_vc_config_channel(voltdm
);
752 omap_vc_i2c_init(voltdm
);
754 if (cpu_is_omap34xx())
755 omap3_vc_init_channel(voltdm
);
756 else if (cpu_is_omap44xx())
757 omap4_vc_init_channel(voltdm
);