/*
* 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 <plat/cpu.h>
#include "voltage.h"
#include "vc.h"
#include "prm-regbits-34xx.h"
#include "prm-regbits-44xx.h"
#include "prm44xx.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;
#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);
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;
}
static void __init omap3_vfsm_init(struct voltagedomain *voltdm)
{
/*
* Voltage Manager FSM parameters init
* XXX This data should be passed in from the board file
*/
voltdm->write(OMAP3_CLKSETUP, OMAP3_PRM_CLKSETUP_OFFSET);
voltdm->write(OMAP3_VOLTOFFSET, OMAP3_PRM_VOLTOFFSET_OFFSET);
voltdm->write(OMAP3_VOLTSETUP2, OMAP3_PRM_VOLTSETUP2_OFFSET);
}
static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
{
static bool is_initialized;
if (is_initialized)
return;
omap3_vfsm_init(voltdm);
is_initialized = true;
}
/* OMAP4 specific voltage init functions */
static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
{
static bool is_initialized;
u32 vc_val;
if (is_initialized)
return;
/* XXX These are magic numbers and do not belong! */
vc_val = (0x60 << OMAP4430_SCLL_SHIFT | 0x26 << OMAP4430_SCLH_SHIFT);
voltdm->write(vc_val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
is_initialized = true;
}
/**
* omap_vc_i2c_init - initialize I2C interface to PMIC
* @voltdm: voltage domain containing VC data
*
* Use PMIC supplied seetings 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 all channels must match.",
__func__);
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);
initialized = true;
}
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: PMIC info requried to configure vc for"
"vdd_%s not populated.Hence cannot initialize vc\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;
vc->setup_time = voltdm->pmic->volt_setup_time;
/* 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 | vc_cfg_bits->racen;
}
/* Set up the on, inactive, retention and off voltage */
on_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->on_volt);
onlp_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->onlp_volt);
ret_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->ret_volt);
off_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->off_volt);
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);
/* Configure the setup times */
voltdm->rmw(voltdm->vfsm->voltsetup_mask,
vc->setup_time << __ffs(voltdm->vfsm->voltsetup_mask),
voltdm->vfsm->voltsetup_reg);
omap_vc_i2c_init(voltdm);
if (cpu_is_omap34xx())
omap3_vc_init_channel(voltdm);
else if (cpu_is_omap44xx())
omap4_vc_init_channel(voltdm);
}
