1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) 2011 The Chromium OS Authors.
4 * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.com>
5 */
6
7 #include <common.h>
8 #include <log.h>
9 #include <tps6586x.h>
10 #include <asm/io.h>
11 #include <i2c.h>
12 #include <linux/delay.h>
13
14 static struct udevice *tps6586x_dev;
15
16 enum {
17 /* Registers that we access */
18 SUPPLY_CONTROL1 = 0x20,
19 SUPPLY_CONTROL2,
20 SM1_VOLTAGE_V1 = 0x23,
21 SM1_VOLTAGE_V2,
22 SM0_VOLTAGE_V1 = 0x26,
23 SM0_VOLTAGE_V2,
24 PFM_MODE = 0x47,
25
26 /* Bits in the supply control registers */
27 CTRL_SM1_RAMP = 0x01,
28 CTRL_SM1_SUPPLY2 = 0x02,
29 CTRL_SM0_RAMP = 0x04,
30 CTRL_SM0_SUPPLY2 = 0x08,
31 };
32
33 #define MAX_I2C_RETRY 3
tps6586x_read(int reg)34 static int tps6586x_read(int reg)
35 {
36 int i;
37 uchar data;
38 int retval = -1;
39
40 for (i = 0; i < MAX_I2C_RETRY; ++i) {
41 if (!dm_i2c_read(tps6586x_dev, reg, &data, 1)) {
42 retval = (int)data;
43 goto exit;
44 }
45
46 /* i2c access failed, retry */
47 udelay(100);
48 }
49
50 exit:
51 debug("pmu_read %x=%x\n", reg, retval);
52 if (retval < 0)
53 debug("%s: failed to read register %#x: %d\n", __func__, reg,
54 retval);
55 return retval;
56 }
57
tps6586x_write(int reg,uchar * data,uint len)58 static int tps6586x_write(int reg, uchar *data, uint len)
59 {
60 int i;
61 int retval = -1;
62
63 for (i = 0; i < MAX_I2C_RETRY; ++i) {
64 if (!dm_i2c_write(tps6586x_dev, reg, data, len)) {
65 retval = 0;
66 goto exit;
67 }
68
69 /* i2c access failed, retry */
70 udelay(100);
71 }
72
73 exit:
74 debug("pmu_write %x=%x: ", reg, retval);
75 for (i = 0; i < len; i++)
76 debug("%x ", data[i]);
77 if (retval)
78 debug("%s: failed to write register %#x\n", __func__, reg);
79 return retval;
80 }
81
82 /*
83 * Get current voltage of SM0 and SM1
84 *
85 * @param sm0 Place to put SM0 voltage
86 * @param sm1 Place to put SM1 voltage
87 * @return 0 if ok, -1 on error
88 */
read_voltages(int * sm0,int * sm1)89 static int read_voltages(int *sm0, int *sm1)
90 {
91 int ctrl1, ctrl2;
92 int is_v2;
93
94 /*
95 * Each vdd has two supply sources, ie, v1 and v2.
96 * The supply control reg1 and reg2 determine the current selection.
97 */
98 ctrl1 = tps6586x_read(SUPPLY_CONTROL1);
99 ctrl2 = tps6586x_read(SUPPLY_CONTROL2);
100 if (ctrl1 == -1 || ctrl2 == -1)
101 return -ENOTSUPP;
102
103 /* Figure out whether V1 or V2 is selected */
104 is_v2 = (ctrl1 | ctrl2) & CTRL_SM0_SUPPLY2;
105 *sm0 = tps6586x_read(is_v2 ? SM0_VOLTAGE_V2 : SM0_VOLTAGE_V1);
106 *sm1 = tps6586x_read(is_v2 ? SM1_VOLTAGE_V2 : SM1_VOLTAGE_V1);
107 if (*sm0 == -1 || *sm1 == -1)
108 return -ENOTSUPP;
109
110 return 0;
111 }
112
set_voltage(int reg,int data,int rate)113 static int set_voltage(int reg, int data, int rate)
114 {
115 uchar control_bit;
116 uchar buff[3];
117
118 control_bit = (reg == SM0_VOLTAGE_V1 ? CTRL_SM0_RAMP : CTRL_SM1_RAMP);
119
120 /*
121 * Only one supply is needed in u-boot. set both v1 and v2 to
122 * same value.
123 *
124 * When both v1 and v2 are set to same value, we just need to set
125 * control1 reg to trigger the supply selection.
126 */
127 buff[0] = buff[1] = (uchar)data;
128 buff[2] = rate;
129
130 /* write v1, v2 and rate, then trigger */
131 if (tps6586x_write(reg, buff, 3) ||
132 tps6586x_write(SUPPLY_CONTROL1, &control_bit, 1))
133 return -ENOTSUPP;
134
135 return 0;
136 }
137
calculate_next_voltage(int voltage,int target,int step)138 static int calculate_next_voltage(int voltage, int target, int step)
139 {
140 int diff = voltage < target ? step : -step;
141
142 if (abs(target - voltage) > step)
143 voltage += diff;
144 else
145 voltage = target;
146
147 return voltage;
148 }
149
tps6586x_set_pwm_mode(int mask)150 int tps6586x_set_pwm_mode(int mask)
151 {
152 uchar val;
153 int ret;
154
155 assert(tps6586x_dev);
156 ret = tps6586x_read(PFM_MODE);
157 if (ret != -1) {
158 val = (uchar)ret;
159 val |= mask;
160
161 ret = tps6586x_write(PFM_MODE, &val, 1);
162 }
163
164 if (ret == -1)
165 debug("%s: Failed to read/write PWM mode reg\n", __func__);
166
167 return ret;
168 }
169
tps6586x_adjust_sm0_sm1(int sm0_target,int sm1_target,int step,int rate,int min_sm0_over_sm1)170 int tps6586x_adjust_sm0_sm1(int sm0_target, int sm1_target, int step, int rate,
171 int min_sm0_over_sm1)
172 {
173 int sm0, sm1;
174 int bad;
175
176 assert(tps6586x_dev);
177
178 /* get current voltage settings */
179 if (read_voltages(&sm0, &sm1)) {
180 debug("%s: Cannot read voltage settings\n", __func__);
181 return -EINVAL;
182 }
183
184 /*
185 * if vdd_core < vdd_cpu + rel
186 * skip
187 *
188 * This condition may happen when system reboots due to kernel crash.
189 */
190 if (min_sm0_over_sm1 != -1 && sm0 < sm1 + min_sm0_over_sm1) {
191 debug("%s: SM0 is %d, SM1 is %d, but min_sm0_over_sm1 is %d\n",
192 __func__, sm0, sm1, min_sm0_over_sm1);
193 return -EINVAL;
194 }
195
196 /*
197 * Since vdd_core and vdd_cpu may both stand at either greater or less
198 * than their nominal voltage, the adjustment may go either directions.
199 *
200 * Make sure vdd_core is always higher than vdd_cpu with certain margin.
201 * So, find out which vdd to adjust first in each step.
202 *
203 * case 1: both sm0 and sm1 need to move up
204 * adjust sm0 before sm1
205 *
206 * case 2: both sm0 and sm1 need to move down
207 * adjust sm1 before sm0
208 *
209 * case 3: sm0 moves down and sm1 moves up
210 * adjusting either one first is fine.
211 *
212 * Adjust vdd_core and vdd_cpu one step at a time until they reach
213 * their nominal values.
214 */
215 bad = 0;
216 while (!bad && (sm0 != sm0_target || sm1 != sm1_target)) {
217 int adjust_sm0_late = 0; /* flag to adjust vdd_core later */
218
219 debug("%d-%d %d-%d ", sm0, sm0_target, sm1, sm1_target);
220
221 if (sm0 != sm0_target) {
222 /*
223 * if case 1 and case 3, set new sm0 first.
224 * otherwise, hold down until new sm1 is set.
225 */
226 sm0 = calculate_next_voltage(sm0, sm0_target, step);
227 if (sm1 < sm1_target)
228 bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
229 else
230 adjust_sm0_late = 1;
231 }
232
233 if (sm1 != sm1_target) {
234 sm1 = calculate_next_voltage(sm1, sm1_target, step);
235 bad |= set_voltage(SM1_VOLTAGE_V1, sm1, rate);
236 }
237
238 if (adjust_sm0_late)
239 bad |= set_voltage(SM0_VOLTAGE_V1, sm0, rate);
240 debug("%d\n", adjust_sm0_late);
241 }
242 debug("%d-%d %d-%d done\n", sm0, sm0_target, sm1, sm1_target);
243
244 return bad ? -EINVAL : 0;
245 }
246
tps6586x_init(struct udevice * dev)247 int tps6586x_init(struct udevice *dev)
248 {
249 tps6586x_dev = dev;
250
251 return 0;
252 }
253