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- /*
- * 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++;
- }
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