Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 843 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
new file mode 100644
index 000000000..d76b1e5eb
--- /dev/null
+++ b/arch/arm/mach-omap2/vc.c
@@ -0,0 +1,843 @@
+/*
+ * 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, &current_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_warn("%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);
+}
+
+struct omap3_vc_timings {
+	u32 voltsetup1;
+	u32 voltsetup2;
+};
+
+struct omap3_vc {
+	struct voltagedomain *vd;
+	u32 voltctrl;
+	u32 voltsetup1;
+	u32 voltsetup2;
+	struct omap3_vc_timings timings[2];
+};
+static struct omap3_vc vc;
+
+void omap3_vc_set_pmic_signaling(int core_next_state)
+{
+	struct voltagedomain *vd = vc.vd;
+	struct omap3_vc_timings *c = vc.timings;
+	u32 voltctrl, voltsetup1, voltsetup2;
+
+	voltctrl = vc.voltctrl;
+	voltsetup1 = vc.voltsetup1;
+	voltsetup2 = vc.voltsetup2;
+
+	switch (core_next_state) {
+	case PWRDM_POWER_OFF:
+		voltctrl &= ~(OMAP3430_PRM_VOLTCTRL_AUTO_RET |
+			      OMAP3430_PRM_VOLTCTRL_AUTO_SLEEP);
+		voltctrl |= OMAP3430_PRM_VOLTCTRL_AUTO_OFF;
+		if (voltctrl & OMAP3430_PRM_VOLTCTRL_SEL_OFF)
+			voltsetup2 = c->voltsetup2;
+		else
+			voltsetup1 = c->voltsetup1;
+		break;
+	case PWRDM_POWER_RET:
+	default:
+		c++;
+		voltctrl &= ~(OMAP3430_PRM_VOLTCTRL_AUTO_OFF |
+			      OMAP3430_PRM_VOLTCTRL_AUTO_SLEEP);
+		voltctrl |= OMAP3430_PRM_VOLTCTRL_AUTO_RET;
+		voltsetup1 = c->voltsetup1;
+		break;
+	}
+
+	if (voltctrl != vc.voltctrl) {
+		vd->write(voltctrl, OMAP3_PRM_VOLTCTRL_OFFSET);
+		vc.voltctrl = voltctrl;
+	}
+	if (voltsetup1 != vc.voltsetup1) {
+		vd->write(c->voltsetup1,
+			  OMAP3_PRM_VOLTSETUP1_OFFSET);
+		vc.voltsetup1 = voltsetup1;
+	}
+	if (voltsetup2 != vc.voltsetup2) {
+		vd->write(c->voltsetup2,
+			  OMAP3_PRM_VOLTSETUP2_OFFSET);
+		vc.voltsetup2 = voltsetup2;
+	}
+}
+
+/*
+ * Configure signal polarity for sys_clkreq and sys_off_mode pins
+ * as the default values are wrong and can cause the system to hang
+ * if any twl4030 scripts are loaded.
+ */
+static void __init omap3_vc_init_pmic_signaling(struct voltagedomain *voltdm)
+{
+	u32 val;
+
+	if (vc.vd)
+		return;
+
+	vc.vd = voltdm;
+
+	val = voltdm->read(OMAP3_PRM_POLCTRL_OFFSET);
+	if (!(val & OMAP3430_PRM_POLCTRL_CLKREQ_POL) ||
+	    (val & OMAP3430_PRM_POLCTRL_OFFMODE_POL)) {
+		val |= OMAP3430_PRM_POLCTRL_CLKREQ_POL;
+		val &= ~OMAP3430_PRM_POLCTRL_OFFMODE_POL;
+		pr_debug("PM: fixing sys_clkreq and sys_off_mode polarity to 0x%x\n",
+			 val);
+		voltdm->write(val, OMAP3_PRM_POLCTRL_OFFSET);
+	}
+
+	/*
+	 * By default let's use I2C4 signaling for retention idle
+	 * and sys_off_mode pin signaling for off idle. This way we
+	 * have sys_clk_req pin go down for retention and both
+	 * sys_clk_req and sys_off_mode pins will go down for off
+	 * idle. And we can also scale voltages to zero for off-idle.
+	 * Note that no actual voltage scaling during off-idle will
+	 * happen unless the board specific twl4030 PMIC scripts are
+	 * loaded. See also omap_vc_i2c_init for comments regarding
+	 * erratum i531.
+	 */
+	val = voltdm->read(OMAP3_PRM_VOLTCTRL_OFFSET);
+	if (!(val & OMAP3430_PRM_VOLTCTRL_SEL_OFF)) {
+		val |= OMAP3430_PRM_VOLTCTRL_SEL_OFF;
+		pr_debug("PM: setting voltctrl sys_off_mode signaling to 0x%x\n",
+			 val);
+		voltdm->write(val, OMAP3_PRM_VOLTCTRL_OFFSET);
+	}
+	vc.voltctrl = val;
+
+	omap3_vc_set_pmic_signaling(PWRDM_POWER_ON);
+}
+
+static void omap3_init_voltsetup1(struct voltagedomain *voltdm,
+				  struct omap3_vc_timings *c, u32 idle)
+{
+	unsigned long val;
+
+	val = (voltdm->vc_param->on - idle) / voltdm->pmic->slew_rate;
+	val *= voltdm->sys_clk.rate / 8 / 1000000 + 1;
+	val <<= __ffs(voltdm->vfsm->voltsetup_mask);
+	c->voltsetup1 &= ~voltdm->vfsm->voltsetup_mask;
+	c->voltsetup1 |= val;
+}
+
+/**
+ * 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.
+ *
+ * Note that pmic is not controlling the voltage scaling during
+ * retention signaled over I2C4, so we can keep voltsetup2 as 0.
+ * And the oscillator is not shut off over I2C4, so no need to
+ * set clksetup.
+ */
+static void omap3_set_i2c_timings(struct voltagedomain *voltdm)
+{
+	struct omap3_vc_timings *c = vc.timings;
+
+	/* Configure PRWDM_POWER_OFF over I2C4 */
+	omap3_init_voltsetup1(voltdm, c, voltdm->vc_param->off);
+	c++;
+	/* Configure PRWDM_POWER_RET over I2C4 */
+	omap3_init_voltsetup1(voltdm, c, voltdm->vc_param->ret);
+}
+
+/**
+ * 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.n,
+ * 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.
+ *
+ * Note that omap is not controlling the voltage scaling during
+ * off idle signaled by sys_off_mode, so we can keep voltsetup1
+ * as 0.
+ */
+static void omap3_set_off_timings(struct voltagedomain *voltdm)
+{
+	struct omap3_vc_timings *c = vc.timings;
+	u32 tstart, tshut, clksetup, voltoffset;
+
+	if (c->voltsetup2)
+		return;
+
+	omap_pm_get_oscillator(&tstart, &tshut);
+	if (tstart == ULONG_MAX) {
+		pr_debug("PM: oscillator start-up time not initialized, using 10ms\n");
+		clksetup = omap_usec_to_32k(10000);
+	} else {
+		clksetup = omap_usec_to_32k(tstart);
+	}
+
+	/*
+	 * For twl4030 errata 27, we need to allow minimum ~488.32 us wait to
+	 * switch from HFCLKIN to internal oscillator. That means timings
+	 * have voltoffset fixed to 0xa in rounded up 32 KiHz cycles. And
+	 * that means we can calculate the value based on the oscillator
+	 * start-up time since voltoffset2 = clksetup - voltoffset.
+	 */
+	voltoffset = omap_usec_to_32k(488);
+	c->voltsetup2 = clksetup - voltoffset;
+	voltdm->write(clksetup, OMAP3_PRM_CLKSETUP_OFFSET);
+	voltdm->write(voltoffset, OMAP3_PRM_VOLTOFFSET_OFFSET);
+}
+
+static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
+{
+	omap3_vc_init_pmic_signaling(voltdm);
+	omap3_set_off_timings(voltdm);
+	omap3_set_i2c_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);
+
+	writel_relaxed(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 struct i2c_init_data omap4_i2c_timing_data[] __initconst = {
+	{
+		.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 */
+	writel_relaxed(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;
+	}
+
+	/*
+	 * Note that for omap3 OMAP3430_SREN_MASK clears SREN to work around
+	 * erratum i531 "Extra Power Consumed When Repeated Start Operation
+	 * Mode Is Enabled on I2C Interface Dedicated for Smart Reflex (I2C4)".
+	 * Otherwise I2C4 eventually leads into about 23mW extra power being
+	 * consumed even during off idle using VMODE.
+	 */
+	i2c_high_speed = voltdm->pmic->i2c_high_speed;
+	if (i2c_high_speed)
+		voltdm->rmw(vc->common->i2c_cfg_clear_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);
+}
+