tps6586x.c 5.5 KB
Newer Older
Simon Glass's avatar
Simon Glass committed
1 2 3 4
/*
 * Copyright (c) 2011 The Chromium OS Authors.
 * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.com>
 *
5
 * SPDX-License-Identifier:	GPL-2.0+
Simon Glass's avatar
Simon Glass committed
6 7 8 9 10 11 12
 */

#include <common.h>
#include <tps6586x.h>
#include <asm/io.h>
#include <i2c.h>

13
static struct udevice *tps6586x_dev;
Simon Glass's avatar
Simon Glass committed
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

enum {
	/* Registers that we access */
	SUPPLY_CONTROL1		= 0x20,
	SUPPLY_CONTROL2,
	SM1_VOLTAGE_V1		= 0x23,
	SM1_VOLTAGE_V2,
	SM0_VOLTAGE_V1		= 0x26,
	SM0_VOLTAGE_V2,
	PFM_MODE		= 0x47,

	/* Bits in the supply control registers */
	CTRL_SM1_RAMP		= 0x01,
	CTRL_SM1_SUPPLY2	= 0x02,
	CTRL_SM0_RAMP		= 0x04,
	CTRL_SM0_SUPPLY2	= 0x08,
};

#define MAX_I2C_RETRY	3
33
static int tps6586x_read(int reg)
Simon Glass's avatar
Simon Glass committed
34 35 36 37 38 39
{
	int	i;
	uchar	data;
	int	retval = -1;

	for (i = 0; i < MAX_I2C_RETRY; ++i) {
40
		if (!dm_i2c_read(tps6586x_dev, reg,  &data, 1)) {
Simon Glass's avatar
Simon Glass committed
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
			retval = (int)data;
			goto exit;
		}

		/* i2c access failed, retry */
		udelay(100);
	}

exit:
	debug("pmu_read %x=%x\n", reg, retval);
	if (retval < 0)
		debug("%s: failed to read register %#x: %d\n", __func__, reg,
		      retval);
	return retval;
}

57
static int tps6586x_write(int reg, uchar *data, uint len)
Simon Glass's avatar
Simon Glass committed
58 59 60 61 62
{
	int	i;
	int	retval = -1;

	for (i = 0; i < MAX_I2C_RETRY; ++i) {
63
		if (!dm_i2c_write(tps6586x_dev, reg, data, len)) {
Simon Glass's avatar
Simon Glass committed
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153
			retval = 0;
			goto exit;
		}

		/* i2c access failed, retry */
		udelay(100);
	}

exit:
	debug("pmu_write %x=%x: ", reg, retval);
	for (i = 0; i < len; i++)
		debug("%x ", data[i]);
	if (retval)
		debug("%s: failed to write register %#x\n", __func__, reg);
	return retval;
}

/*
 * Get current voltage of SM0 and SM1
 *
 * @param sm0	Place to put SM0 voltage
 * @param sm1	Place to put SM1 voltage
 * @return 0 if ok, -1 on error
 */
static int read_voltages(int *sm0, int *sm1)
{
	int ctrl1, ctrl2;
	int is_v2;

	/*
	 * Each vdd has two supply sources, ie, v1 and v2.
	 * The supply control reg1 and reg2 determine the current selection.
	 */
	ctrl1 = tps6586x_read(SUPPLY_CONTROL1);
	ctrl2 = tps6586x_read(SUPPLY_CONTROL2);
	if (ctrl1 == -1 || ctrl2 == -1)
		return -1;

	/* Figure out whether V1 or V2 is selected */
	is_v2 = (ctrl1 | ctrl2) & CTRL_SM0_SUPPLY2;
	*sm0 = tps6586x_read(is_v2 ? SM0_VOLTAGE_V2 : SM0_VOLTAGE_V1);
	*sm1 = tps6586x_read(is_v2 ? SM1_VOLTAGE_V2 : SM1_VOLTAGE_V1);
	if (*sm0 == -1 || *sm1 == -1)
		return -1;

	return 0;
}

static int set_voltage(int reg, int data, int rate)
{
	uchar control_bit;
	uchar buff[3];

	control_bit = (reg == SM0_VOLTAGE_V1 ? CTRL_SM0_RAMP : CTRL_SM1_RAMP);

	/*
	 * Only one supply is needed in u-boot. set both v1 and v2 to
	 * same value.
	 *
	 * When both v1 and v2 are set to same value, we just need to set
	 * control1 reg to trigger the supply selection.
	 */
	buff[0] = buff[1] = (uchar)data;
	buff[2] = rate;

	/* write v1, v2 and rate, then trigger */
	if (tps6586x_write(reg, buff, 3) ||
	    tps6586x_write(SUPPLY_CONTROL1, &control_bit, 1))
		return -1;

	return 0;
}

static int calculate_next_voltage(int voltage, int target, int step)
{
	int diff = voltage < target ? step : -step;

	if (abs(target - voltage) > step)
		voltage += diff;
	else
		voltage = target;

	return voltage;
}

int tps6586x_set_pwm_mode(int mask)
{
	uchar val;
	int ret;

154
	assert(tps6586x_dev);
Simon Glass's avatar
Simon Glass committed
155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174
	ret = tps6586x_read(PFM_MODE);
	if (ret != -1) {
		val = (uchar)ret;
		val |= mask;

		ret = tps6586x_write(PFM_MODE, &val, 1);
	}

	if (ret == -1)
		debug("%s: Failed to read/write PWM mode reg\n", __func__);

	return ret;
}

int tps6586x_adjust_sm0_sm1(int sm0_target, int sm1_target, int step, int rate,
			    int min_sm0_over_sm1)
{
	int sm0, sm1;
	int bad;

175
	assert(tps6586x_dev);
Simon Glass's avatar
Simon Glass committed
176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245

	/* get current voltage settings */
	if (read_voltages(&sm0, &sm1)) {
		debug("%s: Cannot read voltage settings\n", __func__);
		return -1;
	}

	/*
	 * if vdd_core < vdd_cpu + rel
	 *    skip
	 *
	 * This condition may happen when system reboots due to kernel crash.
	 */
	if (min_sm0_over_sm1 != -1 && sm0 < sm1 + min_sm0_over_sm1) {
		debug("%s: SM0 is %d, SM1 is %d, but min_sm0_over_sm1 is %d\n",
		      __func__, sm0, sm1, min_sm0_over_sm1);
		return -1;
	}

	/*
	 * Since vdd_core and vdd_cpu may both stand at either greater or less
	 * than their nominal voltage, the adjustment may go either directions.
	 *
	 * Make sure vdd_core is always higher than vdd_cpu with certain margin.
	 * So, find out which vdd to adjust first in each step.
	 *
	 * case 1: both sm0 and sm1 need to move up
	 *              adjust sm0 before sm1
	 *
	 * case 2: both sm0 and sm1 need to move down
	 *              adjust sm1 before sm0
	 *
	 * case 3: sm0 moves down and sm1 moves up
	 *              adjusting either one first is fine.
	 *
	 * Adjust vdd_core and vdd_cpu one step at a time until they reach
	 * their nominal values.
	 */
	bad = 0;
	while (!bad && (sm0 != sm0_target || sm1 != sm1_target)) {
		int adjust_sm0_late = 0; /* flag to adjust vdd_core later */

		debug("%d-%d   %d-%d   ", sm0, sm0_target, sm1, sm1_target);

		if (sm0 != sm0_target) {
			/*
			 * if case 1 and case 3, set new sm0 first.
			 * otherwise, hold down until new sm1 is set.
			 */
			sm0 = calculate_next_voltage(sm0, sm0_target, step);
			if (sm1 < sm1_target)
				bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
			else
				adjust_sm0_late = 1;
		}

		if (sm1 != sm1_target) {
			sm1 = calculate_next_voltage(sm1, sm1_target, step);
			bad |= set_voltage(SM1_VOLTAGE_V1, sm1, rate);
		}

		if (adjust_sm0_late)
			bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
		debug("%d\n", adjust_sm0_late);
	}
	debug("%d-%d   %d-%d   done\n", sm0, sm0_target, sm1, sm1_target);

	return bad ? -1 : 0;
}

246
int tps6586x_init(struct udevice *dev)
Simon Glass's avatar
Simon Glass committed
247
{
248
	tps6586x_dev = dev;
Simon Glass's avatar
Simon Glass committed
249 250 251

	return 0;
}