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1 | /* |
2 | * Copyright (c) 2011 The Chromium OS Authors. | |
3 | * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.com> | |
4 | * | |
5 | * See file CREDITS for list of people who contributed to this | |
6 | * project. | |
7 | * | |
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. | |
12 | * | |
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. | |
17 | * | |
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, | |
21 | * MA 02111-1307 USA | |
22 | */ | |
23 | ||
24 | #include <common.h> | |
25 | #include <tps6586x.h> | |
26 | #include <asm/io.h> | |
27 | #include <i2c.h> | |
28 | ||
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 */ | |
32 | ||
33 | enum { | |
34 | /* Registers that we access */ | |
35 | SUPPLY_CONTROL1 = 0x20, | |
36 | SUPPLY_CONTROL2, | |
37 | SM1_VOLTAGE_V1 = 0x23, | |
38 | SM1_VOLTAGE_V2, | |
39 | SM0_VOLTAGE_V1 = 0x26, | |
40 | SM0_VOLTAGE_V2, | |
41 | PFM_MODE = 0x47, | |
42 | ||
43 | /* Bits in the supply control registers */ | |
44 | CTRL_SM1_RAMP = 0x01, | |
45 | CTRL_SM1_SUPPLY2 = 0x02, | |
46 | CTRL_SM0_RAMP = 0x04, | |
47 | CTRL_SM0_SUPPLY2 = 0x08, | |
48 | }; | |
49 | ||
50 | #define MAX_I2C_RETRY 3 | |
51 | int tps6586x_read(int reg) | |
52 | { | |
53 | int i; | |
54 | uchar data; | |
55 | int retval = -1; | |
56 | int old_bus_num; | |
57 | ||
58 | old_bus_num = i2c_get_bus_num(); | |
59 | i2c_set_bus_num(bus_num); | |
60 | ||
61 | for (i = 0; i < MAX_I2C_RETRY; ++i) { | |
62 | if (!i2c_read(I2C_ADDRESS, reg, 1, &data, 1)) { | |
63 | retval = (int)data; | |
64 | goto exit; | |
65 | } | |
66 | ||
67 | /* i2c access failed, retry */ | |
68 | udelay(100); | |
69 | } | |
70 | ||
71 | exit: | |
72 | i2c_set_bus_num(old_bus_num); | |
73 | debug("pmu_read %x=%x\n", reg, retval); | |
74 | if (retval < 0) | |
75 | debug("%s: failed to read register %#x: %d\n", __func__, reg, | |
76 | retval); | |
77 | return retval; | |
78 | } | |
79 | ||
80 | int tps6586x_write(int reg, uchar *data, uint len) | |
81 | { | |
82 | int i; | |
83 | int retval = -1; | |
84 | int old_bus_num; | |
85 | ||
86 | old_bus_num = i2c_get_bus_num(); | |
87 | i2c_set_bus_num(bus_num); | |
88 | ||
89 | for (i = 0; i < MAX_I2C_RETRY; ++i) { | |
90 | if (!i2c_write(I2C_ADDRESS, reg, 1, data, len)) { | |
91 | retval = 0; | |
92 | goto exit; | |
93 | } | |
94 | ||
95 | /* i2c access failed, retry */ | |
96 | udelay(100); | |
97 | } | |
98 | ||
99 | exit: | |
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]); | |
104 | if (retval) | |
105 | debug("%s: failed to write register %#x\n", __func__, reg); | |
106 | return retval; | |
107 | } | |
108 | ||
109 | /* | |
110 | * Get current voltage of SM0 and SM1 | |
111 | * | |
112 | * @param sm0 Place to put SM0 voltage | |
113 | * @param sm1 Place to put SM1 voltage | |
114 | * @return 0 if ok, -1 on error | |
115 | */ | |
116 | static int read_voltages(int *sm0, int *sm1) | |
117 | { | |
118 | int ctrl1, ctrl2; | |
119 | int is_v2; | |
120 | ||
121 | /* | |
122 | * Each vdd has two supply sources, ie, v1 and v2. | |
123 | * The supply control reg1 and reg2 determine the current selection. | |
124 | */ | |
125 | ctrl1 = tps6586x_read(SUPPLY_CONTROL1); | |
126 | ctrl2 = tps6586x_read(SUPPLY_CONTROL2); | |
127 | if (ctrl1 == -1 || ctrl2 == -1) | |
128 | return -1; | |
129 | ||
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) | |
135 | return -1; | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static int set_voltage(int reg, int data, int rate) | |
141 | { | |
142 | uchar control_bit; | |
143 | uchar buff[3]; | |
144 | ||
145 | control_bit = (reg == SM0_VOLTAGE_V1 ? CTRL_SM0_RAMP : CTRL_SM1_RAMP); | |
146 | ||
147 | /* | |
148 | * Only one supply is needed in u-boot. set both v1 and v2 to | |
149 | * same value. | |
150 | * | |
151 | * When both v1 and v2 are set to same value, we just need to set | |
152 | * control1 reg to trigger the supply selection. | |
153 | */ | |
154 | buff[0] = buff[1] = (uchar)data; | |
155 | buff[2] = rate; | |
156 | ||
157 | /* write v1, v2 and rate, then trigger */ | |
158 | if (tps6586x_write(reg, buff, 3) || | |
159 | tps6586x_write(SUPPLY_CONTROL1, &control_bit, 1)) | |
160 | return -1; | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | static int calculate_next_voltage(int voltage, int target, int step) | |
166 | { | |
167 | int diff = voltage < target ? step : -step; | |
168 | ||
169 | if (abs(target - voltage) > step) | |
170 | voltage += diff; | |
171 | else | |
172 | voltage = target; | |
173 | ||
174 | return voltage; | |
175 | } | |
176 | ||
177 | int tps6586x_set_pwm_mode(int mask) | |
178 | { | |
179 | uchar val; | |
180 | int ret; | |
181 | ||
182 | assert(inited); | |
183 | ret = tps6586x_read(PFM_MODE); | |
184 | if (ret != -1) { | |
185 | val = (uchar)ret; | |
186 | val |= mask; | |
187 | ||
188 | ret = tps6586x_write(PFM_MODE, &val, 1); | |
189 | } | |
190 | ||
191 | if (ret == -1) | |
192 | debug("%s: Failed to read/write PWM mode reg\n", __func__); | |
193 | ||
194 | return ret; | |
195 | } | |
196 | ||
197 | int tps6586x_adjust_sm0_sm1(int sm0_target, int sm1_target, int step, int rate, | |
198 | int min_sm0_over_sm1) | |
199 | { | |
200 | int sm0, sm1; | |
201 | int bad; | |
202 | ||
203 | assert(inited); | |
204 | ||
205 | /* get current voltage settings */ | |
206 | if (read_voltages(&sm0, &sm1)) { | |
207 | debug("%s: Cannot read voltage settings\n", __func__); | |
208 | return -1; | |
209 | } | |
210 | ||
211 | /* | |
212 | * if vdd_core < vdd_cpu + rel | |
213 | * skip | |
214 | * | |
215 | * This condition may happen when system reboots due to kernel crash. | |
216 | */ | |
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); | |
220 | return -1; | |
221 | } | |
222 | ||
223 | /* | |
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. | |
226 | * | |
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. | |
229 | * | |
230 | * case 1: both sm0 and sm1 need to move up | |
231 | * adjust sm0 before sm1 | |
232 | * | |
233 | * case 2: both sm0 and sm1 need to move down | |
234 | * adjust sm1 before sm0 | |
235 | * | |
236 | * case 3: sm0 moves down and sm1 moves up | |
237 | * adjusting either one first is fine. | |
238 | * | |
239 | * Adjust vdd_core and vdd_cpu one step at a time until they reach | |
240 | * their nominal values. | |
241 | */ | |
242 | bad = 0; | |
243 | while (!bad && (sm0 != sm0_target || sm1 != sm1_target)) { | |
244 | int adjust_sm0_late = 0; /* flag to adjust vdd_core later */ | |
245 | ||
246 | debug("%d-%d %d-%d ", sm0, sm0_target, sm1, sm1_target); | |
247 | ||
248 | if (sm0 != sm0_target) { | |
249 | /* | |
250 | * if case 1 and case 3, set new sm0 first. | |
251 | * otherwise, hold down until new sm1 is set. | |
252 | */ | |
253 | sm0 = calculate_next_voltage(sm0, sm0_target, step); | |
254 | if (sm1 < sm1_target) | |
255 | bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate); | |
256 | else | |
257 | adjust_sm0_late = 1; | |
258 | } | |
259 | ||
260 | if (sm1 != sm1_target) { | |
261 | sm1 = calculate_next_voltage(sm1, sm1_target, step); | |
262 | bad |= set_voltage(SM1_VOLTAGE_V1, sm1, rate); | |
263 | } | |
264 | ||
265 | if (adjust_sm0_late) | |
266 | bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate); | |
267 | debug("%d\n", adjust_sm0_late); | |
268 | } | |
269 | debug("%d-%d %d-%d done\n", sm0, sm0_target, sm1, sm1_target); | |
270 | ||
271 | return bad ? -1 : 0; | |
272 | } | |
273 | ||
274 | int tps6586x_init(int bus) | |
275 | { | |
276 | bus_num = bus; | |
277 | inited = 1; | |
278 | ||
279 | return 0; | |
280 | } |