/*
* OMAP Voltage Controller (VC) interface
*
* Copyright (C) 2011 Texas Instruments, Inc.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/bug.h>
#include <linux/io.h>
#include <asm/div64.h>
#include "iomap.h"
#include "soc.h"
#include "voltage.h"
#include "vc.h"
#include "prm-regbits-34xx.h"
#include "prm-regbits-44xx.h"
#include "prm44xx.h"
#include "pm.h"
#include "scrm44xx.h"
#include "control.h"
/**
* struct omap_vc_channel_cfg - describe the cfg_channel bitfield
* @sa: bit for slave address
* @rav: bit for voltage configuration register
* @rac: bit for command configuration register
* @racen: enable bit for RAC
* @cmd: bit for command value set selection
*
* Channel configuration bits, common for OMAP3+
* OMAP3 register: PRM_VC_CH_CONF
* OMAP4 register: PRM_VC_CFG_CHANNEL
* OMAP5 register: PRM_VC_SMPS_<voltdm>_CONFIG
*/
struct omap_vc_channel_cfg {
u8 sa;
u8 rav;
u8 rac;
u8 racen;
u8 cmd;
};
static struct omap_vc_channel_cfg vc_default_channel_cfg = {
.sa = BIT(0),
.rav = BIT(1),
.rac = BIT(2),
.racen = BIT(3),
.cmd = BIT(4),
};
/*
* On OMAP3+, all VC channels have the above default bitfield
* configuration, except the OMAP4 MPU channel. This appears
* to be a freak accident as every other VC channel has the
* default configuration, thus creating a mutant channel config.
*/
static struct omap_vc_channel_cfg vc_mutant_channel_cfg = {
.sa = BIT(0),
.rav = BIT(2),
.rac = BIT(3),
.racen = BIT(4),
.cmd = BIT(1),
};
static struct omap_vc_channel_cfg *vc_cfg_bits;
/* Default I2C trace length on pcb, 6.3cm. Used for capacitance calculations. */
static u32 sr_i2c_pcb_length = 63;
#define CFG_CHANNEL_MASK 0x1f
/**
* omap_vc_config_channel - configure VC channel to PMIC mappings
* @voltdm: pointer to voltagdomain defining the desired VC channel
*
* Configures the VC channel to PMIC mappings for the following
* PMIC settings
* - i2c slave address (SA)
* - voltage configuration address (RAV)
* - command configuration address (RAC) and enable bit (RACEN)
* - command values for ON, ONLP, RET and OFF (CMD)
*
* This function currently only allows flexible configuration of the
* non-default channel. Starting with OMAP4, there are more than 2
* channels, with one defined as the default (on OMAP4, it's MPU.)
* Only the non-default channel can be configured.
*/
static int omap_vc_config_channel(struct voltagedomain *voltdm)
{
struct omap_vc_channel *vc = voltdm->vc;
/*
* For default channel, the only configurable bit is RACEN.
* All others must stay at zero (see function comment above.)
*/
if (vc->flags & OMAP_VC_CHANNEL_DEFAULT)
vc->cfg_channel &= vc_cfg_bits->racen;
voltdm->rmw(CFG_CHANNEL_MASK << vc->cfg_channel_sa_shift,
vc->cfg_channel << vc->cfg_channel_sa_shift,
vc->cfg_channel_reg);
return 0;
}
/* Voltage scale and accessory APIs */
int omap_vc_pre_scale(struct voltagedomain *voltdm,
unsigned long target_volt,
u8 *target_vsel, u8 *current_vsel)
{
struct omap_vc_channel *vc = voltdm->vc;
u32 vc_cmdval;
/* Check if sufficient pmic info is available for this vdd */
if (!voltdm->pmic) {
pr_err("%s: Insufficient pmic info to scale the vdd_%s\n",
__func__, voltdm->name);
return -EINVAL;
}
if (!voltdm->pmic->uv_to_vsel) {
pr_err("%s: PMIC function to convert voltage in uV to vsel not registered. Hence unable to scale voltage for vdd_%s\n",
__func__, voltdm->name);
return -ENODATA;
}
if (!voltdm->read || !voltdm->write) {
pr_err("%s: No read/write API for accessing vdd_%s regs\n",
__func__, voltdm->name);
return -EINVAL;
}
*target_vsel = voltdm->pmic->uv_to_vsel(target_volt);
*current_vsel = voltdm->pmic->uv_to_vsel(voltdm->nominal_volt);
/* Setting the ON voltage to the new target voltage */
vc_cmdval = voltdm->read(vc->cmdval_reg);
vc_cmdval &= ~vc->common->cmd_on_mask;
vc_cmdval |= (*target_vsel << vc->common->cmd_on_shift);
voltdm->write(vc_cmdval, vc->cmdval_reg);
voltdm->vc_param->on = target_volt;
omap_vp_update_errorgain(voltdm, target_volt);
return 0;
}
void omap_vc_post_scale(struct voltagedomain *voltdm,
unsigned long target_volt,
u8 target_vsel, u8 current_vsel)
{
u32 smps_steps = 0, smps_delay = 0;
smps_steps = abs(target_vsel - current_vsel);
/* SMPS slew rate / step size. 2us added as buffer. */
smps_delay = ((smps_steps * voltdm->pmic->step_size) /
voltdm->pmic->slew_rate) + 2;
udelay(smps_delay);
}
/* vc_bypass_scale - VC bypass method of voltage scaling */
int omap_vc_bypass_scale(struct voltagedomain *voltdm,
unsigned long target_volt)
{
struct omap_vc_channel *vc = voltdm->vc;
u32 loop_cnt = 0, retries_cnt = 0;
u32 vc_valid, vc_bypass_val_reg, vc_bypass_value;
u8 target_vsel, current_vsel;
int ret;
ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, ¤t_vsel);
if (ret)
return ret;
vc_valid = vc->common->valid;
vc_bypass_val_reg = vc->common->bypass_val_reg;
vc_bypass_value = (target_vsel << vc->common->data_shift) |
(vc->volt_reg_addr << vc->common->regaddr_shift) |
(vc->i2c_slave_addr << vc->common->slaveaddr_shift);
voltdm->write(vc_bypass_value, vc_bypass_val_reg);
voltdm->write(vc_bypass_value | vc_valid, vc_bypass_val_reg);
vc_bypass_value = voltdm->read(vc_bypass_val_reg);
/*
* Loop till the bypass command is acknowledged from the SMPS.
* NOTE: This is legacy code. The loop count and retry count needs
* to be revisited.
*/
while (!(vc_bypass_value & vc_valid)) {
loop_cnt++;
if (retries_cnt > 10) {
pr_warning("%s: Retry count exceeded\n", __func__);
return -ETIMEDOUT;
}
if (loop_cnt > 50) {
retries_cnt++;
loop_cnt = 0;
udelay(10);
}
vc_bypass_value = voltdm->read(vc_bypass_val_reg);
}
omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
return 0;
}
/* Convert microsecond value to number of 32kHz clock cycles */
static inline u32 omap_usec_to_32k(u32 usec)
{
return DIV_ROUND_UP_ULL(32768ULL * (u64)usec, 1000000ULL);
}
/* Set oscillator setup time for omap3 */
static void omap3_set_clksetup(u32 usec, struct voltagedomain *voltdm)
{
voltdm->write(omap_usec_to_32k(usec), OMAP3_PRM_CLKSETUP_OFFSET);
}
/**
* omap3_set_i2c_timings - sets i2c sleep timings for a channel
* @voltdm: channel to configure
* @off_mode: select whether retention or off mode values used
*
* Calculates and sets up voltage controller to use I2C based
* voltage scaling for sleep modes. This can be used for either off mode
* or retention. Off mode has additionally an option to use sys_off_mode
* pad, which uses a global signal to program the whole power IC to
* off-mode.
*/
static void omap3_set_i2c_timings(struct voltagedomain *voltdm, bool off_mode)
{
unsigned long voltsetup1;
u32 tgt_volt;
/*
* Oscillator is shut down only if we are using sys_off_mode pad,
* thus we set a minimal setup time here
*/
omap3_set_clksetup(1, voltdm);
if (off_mode)
tgt_volt = voltdm->vc_param->off;
else
tgt_volt = voltdm->vc_param->ret;
voltsetup1 = (voltdm->vc_param->on - tgt_volt) /
voltdm->pmic->slew_rate;
voltsetup1 = voltsetup1 * voltdm->sys_clk.rate / 8 / 1000000 + 1;
voltdm->rmw(voltdm->vfsm->voltsetup_mask,
voltsetup1 << __ffs(voltdm->vfsm->voltsetup_mask),
voltdm->vfsm->voltsetup_reg);
/*
* pmic is not controlling the voltage scaling during retention,
* thus set voltsetup2 to 0
*/
voltdm->write(0, OMAP3_PRM_VOLTSETUP2_OFFSET);
}
/**
* omap3_set_off_timings - sets off-mode timings for a channel
* @voltdm: channel to configure
*
* Calculates and sets up off-mode timings for a channel. Off-mode
* can use either I2C based voltage scaling, or alternatively
* sys_off_mode pad can be used to send a global command to power IC.
* This function first checks which mode is being used, and calls
* omap3_set_i2c_timings() if the system is using I2C control mode.
* sys_off_mode has the additional benefit that voltages can be
* scaled to zero volt level with TWL4030 / TWL5030, I2C can only
* scale to 600mV.
*/
static void omap3_set_off_timings(struct voltagedomain *voltdm)
{
unsigned long clksetup;
unsigned long voltsetup2;
unsigned long voltsetup2_old;
u32 val;
u32 tstart, tshut;
/* check if sys_off_mode is used to control off-mode voltages */
val = voltdm->read(OMAP3_PRM_VOLTCTRL_OFFSET);
if (!(val & OMAP3430_SEL_OFF_MASK)) {
/* No, omap is controlling them over I2C */
omap3_set_i2c_timings(voltdm, true);
return;
}
omap_pm_get_oscillator(&tstart, &tshut);
omap3_set_clksetup(tstart, voltdm);
clksetup = voltdm->read(OMAP3_PRM_CLKSETUP_OFFSET);
/* voltsetup 2 in us */
voltsetup2 = voltdm->vc_param->on / voltdm->pmic->slew_rate;
/* convert to 32k clk cycles */
voltsetup2 = DIV_ROUND_UP(voltsetup2 * 32768, 1000000);
voltsetup2_old = voltdm->read(OMAP3_PRM_VOLTSETUP2_OFFSET);
/*
* Update voltsetup2 if higher than current value (needed because
* we have multiple channels with different ramp times), also
* update voltoffset always to value recommended by TRM
*/
if (voltsetup2 > voltsetup2_old) {
voltdm->write(voltsetup2, OMAP3_PRM_VOLTSETUP2_OFFSET);
voltdm->write(clksetup - voltsetup2,
OMAP3_PRM_VOLTOFFSET_OFFSET);
} else
voltdm->write(clksetup - voltsetup2_old,
OMAP3_PRM_VOLTOFFSET_OFFSET);
/*
* omap is not controlling voltage scaling during off-mode,
* thus set voltsetup1 to 0
*/
voltdm->rmw(voltdm->vfsm->voltsetup_mask, 0,
voltdm->vfsm->voltsetup_reg);
/* voltoffset must be clksetup minus voltsetup2 according to TRM */
voltdm->write(clksetup - voltsetup2, OMAP3_PRM_VOLTOFFSET_OFFSET);
}
static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
{
omap3_set_off_timings(voltdm);
}
/**
* omap4_calc_volt_ramp - calculates voltage ramping delays on omap4
* @voltdm: channel to calculate values for
* @voltage_diff: voltage difference in microvolts
*
* Calculates voltage ramp prescaler + counter values for a voltage
* difference on omap4. Returns a field value suitable for writing to
* VOLTSETUP register for a channel in following format:
* bits[8:9] prescaler ... bits[0:5] counter. See OMAP4 TRM for reference.
*/
static u32 omap4_calc_volt_ramp(struct voltagedomain *voltdm, u32 voltage_diff)
{
u32 prescaler;
u32 cycles;
u32 time;
time = voltage_diff / voltdm->pmic->slew_rate;
cycles = voltdm->sys_clk.rate / 1000 * time / 1000;
cycles /= 64;
prescaler = 0;
/* shift to next prescaler until no overflow */
/* scale for div 256 = 64 * 4 */
if (cycles > 63) {
cycles /= 4;
prescaler++;
}
/* scale for div 512 = 256 * 2 */
if (cycles > 63) {
cycles /= 2;
prescaler++;
}
/* scale for div 2048 = 512 * 4 */
if (cycles > 63) {
cycles /= 4;
prescaler++;
}
/* check for overflow => invalid ramp time */
if (cycles > 63) {
pr_warn("%s: invalid setuptime for vdd_%s\n", __func__,
voltdm->name);
return 0;
}
cycles++;
return (prescaler << OMAP4430_RAMP_UP_PRESCAL_SHIFT) |
(cycles << OMAP4430_RAMP_UP_COUNT_SHIFT);
}
/**
* omap4_usec_to_val_scrm - convert microsecond value to SCRM module bitfield
* @usec: microseconds
* @shift: number of bits to shift left
* @mask: bitfield mask
*
* Converts microsecond value to OMAP4 SCRM bitfield. Bitfield is
* shifted to requested position, and checked agains the mask value.
* If larger, forced to the max value of the field (i.e. the mask itself.)
* Returns the SCRM bitfield value.
*/
static u32 omap4_usec_to_val_scrm(u32 usec, int shift, u32 mask)
{
u32 val;
val = omap_usec_to_32k(usec) << shift;
/* Check for overflow, if yes, force to max value */
if (val > mask)
val = mask;
return val;
}
/**
* omap4_set_timings - set voltage ramp timings for a channel
* @voltdm: channel to configure
* @off_mode: whether off-mode values are used
*
* Calculates and sets the voltage ramp up / down values for a channel.
*/
static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
{
u32 val;
u32 ramp;
int offset;
u32 tstart, tshut;
if (off_mode) {
ramp = omap4_calc_volt_ramp(voltdm,
voltdm->vc_param->on - voltdm->vc_param->off);
offset = voltdm->vfsm->voltsetup_off_reg;
} else {
ramp = omap4_calc_volt_ramp(voltdm,
voltdm->vc_param->on - voltdm->vc_param->ret);
offset = voltdm->vfsm->voltsetup_reg;
}
if (!ramp)
return;
val = voltdm->read(offset);
val |= ramp << OMAP4430_RAMP_DOWN_COUNT_SHIFT;
val |= ramp << OMAP4430_RAMP_UP_COUNT_SHIFT;
voltdm->write(val, offset);
omap_pm_get_oscillator(&tstart, &tshut);
val = omap4_usec_to_val_scrm(tstart, OMAP4_SETUPTIME_SHIFT,
OMAP4_SETUPTIME_MASK);
val |= omap4_usec_to_val_scrm(tshut, OMAP4_DOWNTIME_SHIFT,
OMAP4_DOWNTIME_MASK);
__raw_writel(val, OMAP4_SCRM_CLKSETUPTIME);
}
/* OMAP4 specific voltage init functions */
static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
{
omap4_set_timings(voltdm, true);
omap4_set_timings(voltdm, false);
}
struct i2c_init_data {
u8 loadbits;
u8 load;
u8 hsscll_38_4;
u8 hsscll_26;
u8 hsscll_19_2;
u8 hsscll_16_8;
u8 hsscll_12;
};
static const __initdata struct i2c_init_data omap4_i2c_timing_data[] = {
{
.load = 50,
.loadbits = 0x3,
.hsscll_38_4 = 13,
.hsscll_26 = 11,
.hsscll_19_2 = 9,
.hsscll_16_8 = 9,
.hsscll_12 = 8,
},
{
.load = 25,
.loadbits = 0x2,
.hsscll_38_4 = 13,
.hsscll_26 = 11,
.hsscll_19_2 = 9,
.hsscll_16_8 = 9,
.hsscll_12 = 8,
},
{
.load = 12,
.loadbits = 0x1,
.hsscll_38_4 = 11,
.hsscll_26 = 10,
.hsscll_19_2 = 9,
.hsscll_16_8 = 9,
.hsscll_12 = 8,
},
{
.load = 0,
.loadbits = 0x0,
.hsscll_38_4 = 12,
.hsscll_26 = 10,
.hsscll_19_2 = 9,
.hsscll_16_8 = 8,
.hsscll_12 = 8,
},
};
/**
* omap4_vc_i2c_timing_init - sets up board I2C timing parameters
* @voltdm: voltagedomain pointer to get data from
*
* Use PMIC + board supplied settings for calculating the total I2C
* channel capacitance and set the timing parameters based on this.
* Pre-calculated values are provided in data tables, as it is not
* too straightforward to calculate these runtime.
*/
static void __init omap4_vc_i2c_timing_init(struct voltagedomain *voltdm)
{
u32 capacitance;
u32 val;
u16 hsscll;
const struct i2c_init_data *i2c_data;
if (!voltdm->pmic->i2c_high_speed) {
pr_warn("%s: only high speed supported!\n", __func__);
return;
}
/* PCB trace capacitance, 0.125pF / mm => mm / 8 */
capacitance = DIV_ROUND_UP(sr_i2c_pcb_length, 8);
/* OMAP pad capacitance */
capacitance += 4;
/* PMIC pad capacitance */
capacitance += voltdm->pmic->i2c_pad_load;
/* Search for capacitance match in the table */
i2c_data = omap4_i2c_timing_data;
while (i2c_data->load > capacitance)
i2c_data++;
/* Select proper values based on sysclk frequency */
switch (voltdm->sys_clk.rate) {
case 38400000:
hsscll = i2c_data->hsscll_38_4;
break;
case 26000000:
hsscll = i2c_data->hsscll_26;
break;
case 19200000:
hsscll = i2c_data->hsscll_19_2;
break;
case 16800000:
hsscll = i2c_data->hsscll_16_8;
break;
case 12000000:
hsscll = i2c_data->hsscll_12;
break;
default:
pr_warn("%s: unsupported sysclk rate: %d!\n", __func__,
voltdm->sys_clk.rate);
return;
}
/* Loadbits define pull setup for the I2C channels */
val = i2c_data->loadbits << 25 | i2c_data->loadbits << 29;
/* Write to SYSCTRL_PADCONF_WKUP_CTRL_I2C_2 to setup I2C pull */
__raw_writel(val, OMAP2_L4_IO_ADDRESS(OMAP4_CTRL_MODULE_PAD_WKUP +
OMAP4_CTRL_MODULE_PAD_WKUP_CONTROL_I2C_2));
/* HSSCLH can always be zero */
val = hsscll << OMAP4430_HSSCLL_SHIFT;
val |= (0x28 << OMAP4430_SCLL_SHIFT | 0x2c << OMAP4430_SCLH_SHIFT);
/* Write setup times to I2C config register */
voltdm->write(val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
}
/**
* omap_vc_i2c_init - initialize I2C interface to PMIC
* @voltdm: voltage domain containing VC data
*
* Use PMIC supplied settings for I2C high-speed mode and
* master code (if set) and program the VC I2C configuration
* register.
*
* The VC I2C configuration is common to all VC channels,
* so this function only configures I2C for the first VC
* channel registers. All other VC channels will use the
* same configuration.
*/
static void __init omap_vc_i2c_init(struct voltagedomain *voltdm)
{
struct omap_vc_channel *vc = voltdm->vc;
static bool initialized;
static bool i2c_high_speed;
u8 mcode;
if (initialized) {
if (voltdm->pmic->i2c_high_speed != i2c_high_speed)
pr_warn("%s: I2C config for vdd_%s does not match other channels (%u).\n",
__func__, voltdm->name, i2c_high_speed);
return;
}
i2c_high_speed = voltdm->pmic->i2c_high_speed;
if (i2c_high_speed)
voltdm->rmw(vc->common->i2c_cfg_hsen_mask,
vc->common->i2c_cfg_hsen_mask,
vc->common->i2c_cfg_reg);
mcode = voltdm->pmic->i2c_mcode;
if (mcode)
voltdm->rmw(vc->common->i2c_mcode_mask,
mcode << __ffs(vc->common->i2c_mcode_mask),
vc->common->i2c_cfg_reg);
if (cpu_is_omap44xx())
omap4_vc_i2c_timing_init(voltdm);
initialized = true;
}
/**
* omap_vc_calc_vsel - calculate vsel value for a channel
* @voltdm: channel to calculate value for
* @uvolt: microvolt value to convert to vsel
*
* Converts a microvolt value to vsel value for the used PMIC.
* This checks whether the microvolt value is out of bounds, and
* adjusts the value accordingly. If unsupported value detected,
* warning is thrown.
*/
static u8 omap_vc_calc_vsel(struct voltagedomain *voltdm, u32 uvolt)
{
if (voltdm->pmic->vddmin > uvolt)
uvolt = voltdm->pmic->vddmin;
if (voltdm->pmic->vddmax < uvolt) {
WARN(1, "%s: voltage not supported by pmic: %u vs max %u\n",
__func__, uvolt, voltdm->pmic->vddmax);
/* Lets try maximum value anyway */
uvolt = voltdm->pmic->vddmax;
}
return voltdm->pmic->uv_to_vsel(uvolt);
}
#ifdef CONFIG_PM
/**
* omap_pm_setup_sr_i2c_pcb_length - set length of SR I2C traces on PCB
* @mm: length of the PCB trace in millimetres
*
* Sets the PCB trace length for the I2C channel. By default uses 63mm.
* This is needed for properly calculating the capacitance value for
* the PCB trace, and for setting the SR I2C channel timing parameters.
*/
void __init omap_pm_setup_sr_i2c_pcb_length(u32 mm)
{
sr_i2c_pcb_length = mm;
}
#endif
void __init omap_vc_init_channel(struct voltagedomain *voltdm)
{
struct omap_vc_channel *vc = voltdm->vc;
u8 on_vsel, onlp_vsel, ret_vsel, off_vsel;
u32 val;
if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
pr_err("%s: No PMIC info for vdd_%s\n", __func__, voltdm->name);
return;
}
if (!voltdm->read || !voltdm->write) {
pr_err("%s: No read/write API for accessing vdd_%s regs\n",
__func__, voltdm->name);
return;
}
vc->cfg_channel = 0;
if (vc->flags & OMAP_VC_CHANNEL_CFG_MUTANT)
vc_cfg_bits = &vc_mutant_channel_cfg;
else
vc_cfg_bits = &vc_default_channel_cfg;
/* get PMIC/board specific settings */
vc->i2c_slave_addr = voltdm->pmic->i2c_slave_addr;
vc->volt_reg_addr = voltdm->pmic->volt_reg_addr;
vc->cmd_reg_addr = voltdm->pmic->cmd_reg_addr;
/* Configure the i2c slave address for this VC */
voltdm->rmw(vc->smps_sa_mask,
vc->i2c_slave_addr << __ffs(vc->smps_sa_mask),
vc->smps_sa_reg);
vc->cfg_channel |= vc_cfg_bits->sa;
/*
* Configure the PMIC register addresses.
*/
voltdm->rmw(vc->smps_volra_mask,
vc->volt_reg_addr << __ffs(vc->smps_volra_mask),
vc->smps_volra_reg);
vc->cfg_channel |= vc_cfg_bits->rav;
if (vc->cmd_reg_addr) {
voltdm->rmw(vc->smps_cmdra_mask,
vc->cmd_reg_addr << __ffs(vc->smps_cmdra_mask),
vc->smps_cmdra_reg);
vc->cfg_channel |= vc_cfg_bits->rac;
}
if (vc->cmd_reg_addr == vc->volt_reg_addr)
vc->cfg_channel |= vc_cfg_bits->racen;
/* Set up the on, inactive, retention and off voltage */
on_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->on);
onlp_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->onlp);
ret_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->ret);
off_vsel = omap_vc_calc_vsel(voltdm, voltdm->vc_param->off);
val = ((on_vsel << vc->common->cmd_on_shift) |
(onlp_vsel << vc->common->cmd_onlp_shift) |
(ret_vsel << vc->common->cmd_ret_shift) |
(off_vsel << vc->common->cmd_off_shift));
voltdm->write(val, vc->cmdval_reg);
vc->cfg_channel |= vc_cfg_bits->cmd;
/* Channel configuration */
omap_vc_config_channel(voltdm);
omap_vc_i2c_init(voltdm);
if (cpu_is_omap34xx())
omap3_vc_init_channel(voltdm);
else if (cpu_is_omap44xx())
omap4_vc_init_channel(voltdm);
}