2 * Copyright (c) 2011 The Chromium OS Authors.
3 * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.com>
5 * See file CREDITS for list of people who contributed to this
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29 static int bus_num; /* I2C bus we are on */
30 #define I2C_ADDRESS 0x34 /* chip requires this address */
31 static char inited; /* 1 if we have been inited */
34 /* Registers that we access */
35 SUPPLY_CONTROL1 = 0x20,
37 SM1_VOLTAGE_V1 = 0x23,
39 SM0_VOLTAGE_V1 = 0x26,
43 /* Bits in the supply control registers */
45 CTRL_SM1_SUPPLY2 = 0x02,
47 CTRL_SM0_SUPPLY2 = 0x08,
50 #define MAX_I2C_RETRY 3
51 int tps6586x_read(int reg)
58 old_bus_num = i2c_get_bus_num();
59 i2c_set_bus_num(bus_num);
61 for (i = 0; i < MAX_I2C_RETRY; ++i) {
62 if (!i2c_read(I2C_ADDRESS, reg, 1, &data, 1)) {
67 /* i2c access failed, retry */
72 i2c_set_bus_num(old_bus_num);
73 debug("pmu_read %x=%x\n", reg, retval);
75 debug("%s: failed to read register %#x: %d\n", __func__, reg,
80 int tps6586x_write(int reg, uchar *data, uint len)
86 old_bus_num = i2c_get_bus_num();
87 i2c_set_bus_num(bus_num);
89 for (i = 0; i < MAX_I2C_RETRY; ++i) {
90 if (!i2c_write(I2C_ADDRESS, reg, 1, data, len)) {
95 /* i2c access failed, retry */
100 i2c_set_bus_num(old_bus_num);
101 debug("pmu_write %x=%x: ", reg, retval);
102 for (i = 0; i < len; i++)
103 debug("%x ", data[i]);
105 debug("%s: failed to write register %#x\n", __func__, reg);
110 * Get current voltage of SM0 and SM1
112 * @param sm0 Place to put SM0 voltage
113 * @param sm1 Place to put SM1 voltage
114 * @return 0 if ok, -1 on error
116 static int read_voltages(int *sm0, int *sm1)
122 * Each vdd has two supply sources, ie, v1 and v2.
123 * The supply control reg1 and reg2 determine the current selection.
125 ctrl1 = tps6586x_read(SUPPLY_CONTROL1);
126 ctrl2 = tps6586x_read(SUPPLY_CONTROL2);
127 if (ctrl1 == -1 || ctrl2 == -1)
130 /* Figure out whether V1 or V2 is selected */
131 is_v2 = (ctrl1 | ctrl2) & CTRL_SM0_SUPPLY2;
132 *sm0 = tps6586x_read(is_v2 ? SM0_VOLTAGE_V2 : SM0_VOLTAGE_V1);
133 *sm1 = tps6586x_read(is_v2 ? SM1_VOLTAGE_V2 : SM1_VOLTAGE_V1);
134 if (*sm0 == -1 || *sm1 == -1)
140 static int set_voltage(int reg, int data, int rate)
145 control_bit = (reg == SM0_VOLTAGE_V1 ? CTRL_SM0_RAMP : CTRL_SM1_RAMP);
148 * Only one supply is needed in u-boot. set both v1 and v2 to
151 * When both v1 and v2 are set to same value, we just need to set
152 * control1 reg to trigger the supply selection.
154 buff[0] = buff[1] = (uchar)data;
157 /* write v1, v2 and rate, then trigger */
158 if (tps6586x_write(reg, buff, 3) ||
159 tps6586x_write(SUPPLY_CONTROL1, &control_bit, 1))
165 static int calculate_next_voltage(int voltage, int target, int step)
167 int diff = voltage < target ? step : -step;
169 if (abs(target - voltage) > step)
177 int tps6586x_set_pwm_mode(int mask)
183 ret = tps6586x_read(PFM_MODE);
188 ret = tps6586x_write(PFM_MODE, &val, 1);
192 debug("%s: Failed to read/write PWM mode reg\n", __func__);
197 int tps6586x_adjust_sm0_sm1(int sm0_target, int sm1_target, int step, int rate,
198 int min_sm0_over_sm1)
205 /* get current voltage settings */
206 if (read_voltages(&sm0, &sm1)) {
207 debug("%s: Cannot read voltage settings\n", __func__);
212 * if vdd_core < vdd_cpu + rel
215 * This condition may happen when system reboots due to kernel crash.
217 if (min_sm0_over_sm1 != -1 && sm0 < sm1 + min_sm0_over_sm1) {
218 debug("%s: SM0 is %d, SM1 is %d, but min_sm0_over_sm1 is %d\n",
219 __func__, sm0, sm1, min_sm0_over_sm1);
224 * Since vdd_core and vdd_cpu may both stand at either greater or less
225 * than their nominal voltage, the adjustment may go either directions.
227 * Make sure vdd_core is always higher than vdd_cpu with certain margin.
228 * So, find out which vdd to adjust first in each step.
230 * case 1: both sm0 and sm1 need to move up
231 * adjust sm0 before sm1
233 * case 2: both sm0 and sm1 need to move down
234 * adjust sm1 before sm0
236 * case 3: sm0 moves down and sm1 moves up
237 * adjusting either one first is fine.
239 * Adjust vdd_core and vdd_cpu one step at a time until they reach
240 * their nominal values.
243 while (!bad && (sm0 != sm0_target || sm1 != sm1_target)) {
244 int adjust_sm0_late = 0; /* flag to adjust vdd_core later */
246 debug("%d-%d %d-%d ", sm0, sm0_target, sm1, sm1_target);
248 if (sm0 != sm0_target) {
250 * if case 1 and case 3, set new sm0 first.
251 * otherwise, hold down until new sm1 is set.
253 sm0 = calculate_next_voltage(sm0, sm0_target, step);
254 if (sm1 < sm1_target)
255 bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
260 if (sm1 != sm1_target) {
261 sm1 = calculate_next_voltage(sm1, sm1_target, step);
262 bad |= set_voltage(SM1_VOLTAGE_V1, sm1, rate);
266 bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
267 debug("%d\n", adjust_sm0_late);
269 debug("%d-%d %d-%d done\n", sm0, sm0_target, sm1, sm1_target);
274 int tps6586x_init(int bus)