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git.ipfire.org Git - people/ms/u-boot.git/blob - drivers/power/tps6586x.c
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
)