1 /*
2 * OMAP Voltage Controller (VC) interface
3 *
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 *
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
9 */
10 #include <linux/kernel.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/bug.h>
14
15 #include <plat/cpu.h>
16
17 #include "voltage.h"
18 #include "vc.h"
19 #include "prm-regbits-34xx.h"
20 #include "prm-regbits-44xx.h"
21 #include "prm44xx.h"
22
23 /**
24 * struct omap_vc_channel_cfg - describe the cfg_channel bitfield
25 * @sa: bit for slave address
26 * @rav: bit for voltage configuration register
27 * @rac: bit for command configuration register
28 * @racen: enable bit for RAC
29 * @cmd: bit for command value set selection
30 *
31 * Channel configuration bits, common for OMAP3+
32 * OMAP3 register: PRM_VC_CH_CONF
33 * OMAP4 register: PRM_VC_CFG_CHANNEL
34 * OMAP5 register: PRM_VC_SMPS_<voltdm>_CONFIG
35 */
36 struct omap_vc_channel_cfg {
37 u8 sa;
38 u8 rav;
39 u8 rac;
40 u8 racen;
41 u8 cmd;
42 };
43
44 static struct omap_vc_channel_cfg vc_default_channel_cfg = {
45 .sa = BIT(0),
46 .rav = BIT(1),
47 .rac = BIT(2),
48 .racen = BIT(3),
49 .cmd = BIT(4),
50 };
51
52 /*
53 * On OMAP3+, all VC channels have the above default bitfield
54 * configuration, except the OMAP4 MPU channel. This appears
55 * to be a freak accident as every other VC channel has the
56 * default configuration, thus creating a mutant channel config.
57 */
58 static struct omap_vc_channel_cfg vc_mutant_channel_cfg = {
59 .sa = BIT(0),
60 .rav = BIT(2),
61 .rac = BIT(3),
62 .racen = BIT(4),
63 .cmd = BIT(1),
64 };
65
66 static struct omap_vc_channel_cfg *vc_cfg_bits;
67 #define CFG_CHANNEL_MASK 0x1f
68
69 /**
70 * omap_vc_config_channel - configure VC channel to PMIC mappings
71 * @voltdm: pointer to voltagdomain defining the desired VC channel
72 *
73 * Configures the VC channel to PMIC mappings for the following
74 * PMIC settings
75 * - i2c slave address (SA)
76 * - voltage configuration address (RAV)
77 * - command configuration address (RAC) and enable bit (RACEN)
78 * - command values for ON, ONLP, RET and OFF (CMD)
79 *
80 * This function currently only allows flexible configuration of the
81 * non-default channel. Starting with OMAP4, there are more than 2
82 * channels, with one defined as the default (on OMAP4, it's MPU.)
83 * Only the non-default channel can be configured.
84 */
omap_vc_config_channel(struct voltagedomain * voltdm)85 static int omap_vc_config_channel(struct voltagedomain *voltdm)
86 {
87 struct omap_vc_channel *vc = voltdm->vc;
88
89 /*
90 * For default channel, the only configurable bit is RACEN.
91 * All others must stay at zero (see function comment above.)
92 */
93 if (vc->flags & OMAP_VC_CHANNEL_DEFAULT)
94 vc->cfg_channel &= vc_cfg_bits->racen;
95
96 voltdm->rmw(CFG_CHANNEL_MASK << vc->cfg_channel_sa_shift,
97 vc->cfg_channel << vc->cfg_channel_sa_shift,
98 vc->cfg_channel_reg);
99
100 return 0;
101 }
102
103 /* Voltage scale and accessory APIs */
omap_vc_pre_scale(struct voltagedomain * voltdm,unsigned long target_volt,u8 * target_vsel,u8 * current_vsel)104 int omap_vc_pre_scale(struct voltagedomain *voltdm,
105 unsigned long target_volt,
106 u8 *target_vsel, u8 *current_vsel)
107 {
108 struct omap_vc_channel *vc = voltdm->vc;
109 u32 vc_cmdval;
110
111 /* Check if sufficient pmic info is available for this vdd */
112 if (!voltdm->pmic) {
113 pr_err("%s: Insufficient pmic info to scale the vdd_%s\n",
114 __func__, voltdm->name);
115 return -EINVAL;
116 }
117
118 if (!voltdm->pmic->uv_to_vsel) {
119 pr_err("%s: PMIC function to convert voltage in uV to"
120 "vsel not registered. Hence unable to scale voltage"
121 "for vdd_%s\n", __func__, voltdm->name);
122 return -ENODATA;
123 }
124
125 if (!voltdm->read || !voltdm->write) {
126 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
127 __func__, voltdm->name);
128 return -EINVAL;
129 }
130
131 *target_vsel = voltdm->pmic->uv_to_vsel(target_volt);
132 *current_vsel = voltdm->pmic->uv_to_vsel(voltdm->nominal_volt);
133
134 /* Setting the ON voltage to the new target voltage */
135 vc_cmdval = voltdm->read(vc->cmdval_reg);
136 vc_cmdval &= ~vc->common->cmd_on_mask;
137 vc_cmdval |= (*target_vsel << vc->common->cmd_on_shift);
138 voltdm->write(vc_cmdval, vc->cmdval_reg);
139
140 omap_vp_update_errorgain(voltdm, target_volt);
141
142 return 0;
143 }
144
omap_vc_post_scale(struct voltagedomain * voltdm,unsigned long target_volt,u8 target_vsel,u8 current_vsel)145 void omap_vc_post_scale(struct voltagedomain *voltdm,
146 unsigned long target_volt,
147 u8 target_vsel, u8 current_vsel)
148 {
149 u32 smps_steps = 0, smps_delay = 0;
150
151 smps_steps = abs(target_vsel - current_vsel);
152 /* SMPS slew rate / step size. 2us added as buffer. */
153 smps_delay = ((smps_steps * voltdm->pmic->step_size) /
154 voltdm->pmic->slew_rate) + 2;
155 udelay(smps_delay);
156 }
157
158 /* vc_bypass_scale - VC bypass method of voltage scaling */
omap_vc_bypass_scale(struct voltagedomain * voltdm,unsigned long target_volt)159 int omap_vc_bypass_scale(struct voltagedomain *voltdm,
160 unsigned long target_volt)
161 {
162 struct omap_vc_channel *vc = voltdm->vc;
163 u32 loop_cnt = 0, retries_cnt = 0;
164 u32 vc_valid, vc_bypass_val_reg, vc_bypass_value;
165 u8 target_vsel, current_vsel;
166 int ret;
167
168 ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, ¤t_vsel);
169 if (ret)
170 return ret;
171
172 vc_valid = vc->common->valid;
173 vc_bypass_val_reg = vc->common->bypass_val_reg;
174 vc_bypass_value = (target_vsel << vc->common->data_shift) |
175 (vc->volt_reg_addr << vc->common->regaddr_shift) |
176 (vc->i2c_slave_addr << vc->common->slaveaddr_shift);
177
178 voltdm->write(vc_bypass_value, vc_bypass_val_reg);
179 voltdm->write(vc_bypass_value | vc_valid, vc_bypass_val_reg);
180
181 vc_bypass_value = voltdm->read(vc_bypass_val_reg);
182 /*
183 * Loop till the bypass command is acknowledged from the SMPS.
184 * NOTE: This is legacy code. The loop count and retry count needs
185 * to be revisited.
186 */
187 while (!(vc_bypass_value & vc_valid)) {
188 loop_cnt++;
189
190 if (retries_cnt > 10) {
191 pr_warning("%s: Retry count exceeded\n", __func__);
192 return -ETIMEDOUT;
193 }
194
195 if (loop_cnt > 50) {
196 retries_cnt++;
197 loop_cnt = 0;
198 udelay(10);
199 }
200 vc_bypass_value = voltdm->read(vc_bypass_val_reg);
201 }
202
203 omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
204 return 0;
205 }
206
omap3_vfsm_init(struct voltagedomain * voltdm)207 static void __init omap3_vfsm_init(struct voltagedomain *voltdm)
208 {
209 /*
210 * Voltage Manager FSM parameters init
211 * XXX This data should be passed in from the board file
212 */
213 voltdm->write(OMAP3_CLKSETUP, OMAP3_PRM_CLKSETUP_OFFSET);
214 voltdm->write(OMAP3_VOLTOFFSET, OMAP3_PRM_VOLTOFFSET_OFFSET);
215 voltdm->write(OMAP3_VOLTSETUP2, OMAP3_PRM_VOLTSETUP2_OFFSET);
216 }
217
omap3_vc_init_channel(struct voltagedomain * voltdm)218 static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
219 {
220 static bool is_initialized;
221
222 if (is_initialized)
223 return;
224
225 omap3_vfsm_init(voltdm);
226
227 is_initialized = true;
228 }
229
230
231 /* OMAP4 specific voltage init functions */
omap4_vc_init_channel(struct voltagedomain * voltdm)232 static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
233 {
234 static bool is_initialized;
235 u32 vc_val;
236
237 if (is_initialized)
238 return;
239
240 /* XXX These are magic numbers and do not belong! */
241 vc_val = (0x60 << OMAP4430_SCLL_SHIFT | 0x26 << OMAP4430_SCLH_SHIFT);
242 voltdm->write(vc_val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
243
244 is_initialized = true;
245 }
246
247 /**
248 * omap_vc_i2c_init - initialize I2C interface to PMIC
249 * @voltdm: voltage domain containing VC data
250 *
251 * Use PMIC supplied settings for I2C high-speed mode and
252 * master code (if set) and program the VC I2C configuration
253 * register.
254 *
255 * The VC I2C configuration is common to all VC channels,
256 * so this function only configures I2C for the first VC
257 * channel registers. All other VC channels will use the
258 * same configuration.
259 */
omap_vc_i2c_init(struct voltagedomain * voltdm)260 static void __init omap_vc_i2c_init(struct voltagedomain *voltdm)
261 {
262 struct omap_vc_channel *vc = voltdm->vc;
263 static bool initialized;
264 static bool i2c_high_speed;
265 u8 mcode;
266
267 if (initialized) {
268 if (voltdm->pmic->i2c_high_speed != i2c_high_speed)
269 pr_warn("%s: I2C config for vdd_%s does not match other channels (%u).",
270 __func__, voltdm->name, i2c_high_speed);
271 return;
272 }
273
274 i2c_high_speed = voltdm->pmic->i2c_high_speed;
275 if (i2c_high_speed)
276 voltdm->rmw(vc->common->i2c_cfg_hsen_mask,
277 vc->common->i2c_cfg_hsen_mask,
278 vc->common->i2c_cfg_reg);
279
280 mcode = voltdm->pmic->i2c_mcode;
281 if (mcode)
282 voltdm->rmw(vc->common->i2c_mcode_mask,
283 mcode << __ffs(vc->common->i2c_mcode_mask),
284 vc->common->i2c_cfg_reg);
285
286 initialized = true;
287 }
288
omap_vc_init_channel(struct voltagedomain * voltdm)289 void __init omap_vc_init_channel(struct voltagedomain *voltdm)
290 {
291 struct omap_vc_channel *vc = voltdm->vc;
292 u8 on_vsel, onlp_vsel, ret_vsel, off_vsel;
293 u32 val;
294
295 if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
296 pr_err("%s: No PMIC info for vdd_%s\n", __func__, voltdm->name);
297 return;
298 }
299
300 if (!voltdm->read || !voltdm->write) {
301 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
302 __func__, voltdm->name);
303 return;
304 }
305
306 vc->cfg_channel = 0;
307 if (vc->flags & OMAP_VC_CHANNEL_CFG_MUTANT)
308 vc_cfg_bits = &vc_mutant_channel_cfg;
309 else
310 vc_cfg_bits = &vc_default_channel_cfg;
311
312 /* get PMIC/board specific settings */
313 vc->i2c_slave_addr = voltdm->pmic->i2c_slave_addr;
314 vc->volt_reg_addr = voltdm->pmic->volt_reg_addr;
315 vc->cmd_reg_addr = voltdm->pmic->cmd_reg_addr;
316 vc->setup_time = voltdm->pmic->volt_setup_time;
317
318 /* Configure the i2c slave address for this VC */
319 voltdm->rmw(vc->smps_sa_mask,
320 vc->i2c_slave_addr << __ffs(vc->smps_sa_mask),
321 vc->smps_sa_reg);
322 vc->cfg_channel |= vc_cfg_bits->sa;
323
324 /*
325 * Configure the PMIC register addresses.
326 */
327 voltdm->rmw(vc->smps_volra_mask,
328 vc->volt_reg_addr << __ffs(vc->smps_volra_mask),
329 vc->smps_volra_reg);
330 vc->cfg_channel |= vc_cfg_bits->rav;
331
332 if (vc->cmd_reg_addr) {
333 voltdm->rmw(vc->smps_cmdra_mask,
334 vc->cmd_reg_addr << __ffs(vc->smps_cmdra_mask),
335 vc->smps_cmdra_reg);
336 vc->cfg_channel |= vc_cfg_bits->rac | vc_cfg_bits->racen;
337 }
338
339 /* Set up the on, inactive, retention and off voltage */
340 on_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->on_volt);
341 onlp_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->onlp_volt);
342 ret_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->ret_volt);
343 off_vsel = voltdm->pmic->uv_to_vsel(voltdm->pmic->off_volt);
344 val = ((on_vsel << vc->common->cmd_on_shift) |
345 (onlp_vsel << vc->common->cmd_onlp_shift) |
346 (ret_vsel << vc->common->cmd_ret_shift) |
347 (off_vsel << vc->common->cmd_off_shift));
348 voltdm->write(val, vc->cmdval_reg);
349 vc->cfg_channel |= vc_cfg_bits->cmd;
350
351 /* Channel configuration */
352 omap_vc_config_channel(voltdm);
353
354 /* Configure the setup times */
355 voltdm->rmw(voltdm->vfsm->voltsetup_mask,
356 vc->setup_time << __ffs(voltdm->vfsm->voltsetup_mask),
357 voltdm->vfsm->voltsetup_reg);
358
359 omap_vc_i2c_init(voltdm);
360
361 if (cpu_is_omap34xx())
362 omap3_vc_init_channel(voltdm);
363 else if (cpu_is_omap44xx())
364 omap4_vc_init_channel(voltdm);
365 }
366
367