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