1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4
5 #include "common.h"
6
7 #include "voltage.h"
8 #include "vp.h"
9 #include "prm-regbits-34xx.h"
10 #include "prm-regbits-44xx.h"
11 #include "prm44xx.h"
12
13 static u32 _vp_set_init_voltage(struct voltagedomain *voltdm, u32 volt)
14 {
15 struct omap_vp_instance *vp = voltdm->vp;
16 u32 vpconfig;
17 char vsel;
18
19 vsel = voltdm->pmic->uv_to_vsel(volt);
20
21 vpconfig = voltdm->read(vp->vpconfig);
22 vpconfig &= ~(vp->common->vpconfig_initvoltage_mask |
23 vp->common->vpconfig_forceupdate |
24 vp->common->vpconfig_initvdd);
25 vpconfig |= vsel << __ffs(vp->common->vpconfig_initvoltage_mask);
26 voltdm->write(vpconfig, vp->vpconfig);
27
28 /* Trigger initVDD value copy to voltage processor */
29 voltdm->write((vpconfig | vp->common->vpconfig_initvdd),
30 vp->vpconfig);
31
32 /* Clear initVDD copy trigger bit */
33 voltdm->write(vpconfig, vp->vpconfig);
34
35 return vpconfig;
36 }
37
38 /* Generic voltage init functions */
39 void __init omap_vp_init(struct voltagedomain *voltdm)
40 {
41 struct omap_vp_instance *vp = voltdm->vp;
42 u32 val, sys_clk_rate, timeout, waittime;
43 u32 vddmin, vddmax, vstepmin, vstepmax;
44
45 if (!voltdm->pmic || !voltdm->pmic->uv_to_vsel) {
46 pr_err("%s: No PMIC info for vdd_%s\n", __func__, voltdm->name);
47 return;
48 }
49
50 if (!voltdm->read || !voltdm->write) {
51 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
52 __func__, voltdm->name);
53 return;
54 }
55
56 vp->enabled = false;
57
58 /* Divide to avoid overflow */
59 sys_clk_rate = voltdm->sys_clk.rate / 1000;
60
61 timeout = (sys_clk_rate * voltdm->pmic->vp_timeout_us) / 1000;
62 vddmin = max(voltdm->vp_param->vddmin, voltdm->pmic->vddmin);
63 vddmax = min(voltdm->vp_param->vddmax, voltdm->pmic->vddmax);
64 vddmin = voltdm->pmic->uv_to_vsel(vddmin);
65 vddmax = voltdm->pmic->uv_to_vsel(vddmax);
66
67 waittime = DIV_ROUND_UP(voltdm->pmic->step_size * sys_clk_rate,
68 1000 * voltdm->pmic->slew_rate);
69 vstepmin = voltdm->pmic->vp_vstepmin;
70 vstepmax = voltdm->pmic->vp_vstepmax;
71
72 /*
73 * VP_CONFIG: error gain is not set here, it will be updated
74 * on each scale, based on OPP.
75 */
76 val = (voltdm->pmic->vp_erroroffset <<
77 __ffs(voltdm->vp->common->vpconfig_erroroffset_mask)) |
78 vp->common->vpconfig_timeouten;
79 voltdm->write(val, vp->vpconfig);
80
81 /* VSTEPMIN */
82 val = (waittime << vp->common->vstepmin_smpswaittimemin_shift) |
83 (vstepmin << vp->common->vstepmin_stepmin_shift);
84 voltdm->write(val, vp->vstepmin);
85
86 /* VSTEPMAX */
87 val = (vstepmax << vp->common->vstepmax_stepmax_shift) |
88 (waittime << vp->common->vstepmax_smpswaittimemax_shift);
89 voltdm->write(val, vp->vstepmax);
90
91 /* VLIMITTO */
92 val = (vddmax << vp->common->vlimitto_vddmax_shift) |
93 (vddmin << vp->common->vlimitto_vddmin_shift) |
94 (timeout << vp->common->vlimitto_timeout_shift);
95 voltdm->write(val, vp->vlimitto);
96 }
97
98 int omap_vp_update_errorgain(struct voltagedomain *voltdm,
99 unsigned long target_volt)
100 {
101 struct omap_volt_data *volt_data;
102
103 if (!voltdm->vp)
104 return -EINVAL;
105
106 /* Get volt_data corresponding to target_volt */
107 volt_data = omap_voltage_get_voltdata(voltdm, target_volt);
108 if (IS_ERR(volt_data))
109 return -EINVAL;
110
111 /* Setting vp errorgain based on the voltage */
112 voltdm->rmw(voltdm->vp->common->vpconfig_errorgain_mask,
113 volt_data->vp_errgain <<
114 __ffs(voltdm->vp->common->vpconfig_errorgain_mask),
115 voltdm->vp->vpconfig);
116
117 return 0;
118 }
119
120 /* VP force update method of voltage scaling */
121 int omap_vp_forceupdate_scale(struct voltagedomain *voltdm,
122 unsigned long target_volt)
123 {
124 struct omap_vp_instance *vp = voltdm->vp;
125 u32 vpconfig;
126 u8 target_vsel, current_vsel;
127 int ret, timeout = 0;
128
129 ret = omap_vc_pre_scale(voltdm, target_volt, &target_vsel, ¤t_vsel);
130 if (ret)
131 return ret;
132
133 /*
134 * Clear all pending TransactionDone interrupt/status. Typical latency
135 * is <3us
136 */
137 while (timeout++ < VP_TRANXDONE_TIMEOUT) {
138 vp->common->ops->clear_txdone(vp->id);
139 if (!vp->common->ops->check_txdone(vp->id))
140 break;
141 udelay(1);
142 }
143 if (timeout >= VP_TRANXDONE_TIMEOUT) {
144 pr_warn("%s: vdd_%s TRANXDONE timeout exceeded. Voltage change aborted\n",
145 __func__, voltdm->name);
146 return -ETIMEDOUT;
147 }
148
149 vpconfig = _vp_set_init_voltage(voltdm, target_volt);
150
151 /* Force update of voltage */
152 voltdm->write(vpconfig | vp->common->vpconfig_forceupdate,
153 voltdm->vp->vpconfig);
154
155 /*
156 * Wait for TransactionDone. Typical latency is <200us.
157 * Depends on SMPSWAITTIMEMIN/MAX and voltage change
158 */
159 timeout = 0;
160 omap_test_timeout(vp->common->ops->check_txdone(vp->id),
161 VP_TRANXDONE_TIMEOUT, timeout);
162 if (timeout >= VP_TRANXDONE_TIMEOUT)
163 pr_err("%s: vdd_%s TRANXDONE timeout exceeded. TRANXDONE never got set after the voltage update\n",
164 __func__, voltdm->name);
165
166 omap_vc_post_scale(voltdm, target_volt, target_vsel, current_vsel);
167
168 /*
169 * Disable TransactionDone interrupt , clear all status, clear
170 * control registers
171 */
172 timeout = 0;
173 while (timeout++ < VP_TRANXDONE_TIMEOUT) {
174 vp->common->ops->clear_txdone(vp->id);
175 if (!vp->common->ops->check_txdone(vp->id))
176 break;
177 udelay(1);
178 }
179
180 if (timeout >= VP_TRANXDONE_TIMEOUT)
181 pr_warn("%s: vdd_%s TRANXDONE timeout exceeded while trying to clear the TRANXDONE status\n",
182 __func__, voltdm->name);
183
184 /* Clear force bit */
185 voltdm->write(vpconfig, vp->vpconfig);
186
187 return 0;
188 }
189
190 /**
191 * omap_vp_enable() - API to enable a particular VP
192 * @voltdm: pointer to the VDD whose VP is to be enabled.
193 *
194 * This API enables a particular voltage processor. Needed by the smartreflex
195 * class drivers.
196 */
197 void omap_vp_enable(struct voltagedomain *voltdm)
198 {
199 struct omap_vp_instance *vp;
200 u32 vpconfig, volt;
201
202 if (!voltdm || IS_ERR(voltdm)) {
203 pr_warn("%s: VDD specified does not exist!\n", __func__);
204 return;
205 }
206
207 vp = voltdm->vp;
208 if (!voltdm->read || !voltdm->write) {
209 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
210 __func__, voltdm->name);
211 return;
212 }
213
214 /* If VP is already enabled, do nothing. Return */
215 if (vp->enabled)
216 return;
217
218 volt = voltdm_get_voltage(voltdm);
219 if (!volt) {
220 pr_warn("%s: unable to find current voltage for %s\n",
221 __func__, voltdm->name);
222 return;
223 }
224
225 vpconfig = _vp_set_init_voltage(voltdm, volt);
226
227 /* Enable VP */
228 vpconfig |= vp->common->vpconfig_vpenable;
229 voltdm->write(vpconfig, vp->vpconfig);
230
231 vp->enabled = true;
232 }
233
234 /**
235 * omap_vp_disable() - API to disable a particular VP
236 * @voltdm: pointer to the VDD whose VP is to be disabled.
237 *
238 * This API disables a particular voltage processor. Needed by the smartreflex
239 * class drivers.
240 */
241 void omap_vp_disable(struct voltagedomain *voltdm)
242 {
243 struct omap_vp_instance *vp;
244 u32 vpconfig;
245 int timeout;
246
247 if (!voltdm || IS_ERR(voltdm)) {
248 pr_warn("%s: VDD specified does not exist!\n", __func__);
249 return;
250 }
251
252 vp = voltdm->vp;
253 if (!voltdm->read || !voltdm->write) {
254 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
255 __func__, voltdm->name);
256 return;
257 }
258
259 /* If VP is already disabled, do nothing. Return */
260 if (!vp->enabled) {
261 pr_warn("%s: Trying to disable VP for vdd_%s when it is already disabled\n",
262 __func__, voltdm->name);
263 return;
264 }
265
266 /* Disable VP */
267 vpconfig = voltdm->read(vp->vpconfig);
268 vpconfig &= ~vp->common->vpconfig_vpenable;
269 voltdm->write(vpconfig, vp->vpconfig);
270
271 /*
272 * Wait for VP idle Typical latency is <2us. Maximum latency is ~100us
273 */
274 omap_test_timeout((voltdm->read(vp->vstatus)),
275 VP_IDLE_TIMEOUT, timeout);
276
277 if (timeout >= VP_IDLE_TIMEOUT)
278 pr_warn("%s: vdd_%s idle timedout\n", __func__, voltdm->name);
279
280 vp->enabled = false;
281
282 return;
283 }
284
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