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662a9586 HS |
1 | /* |
2 | * Rockchip IO Voltage Domain driver | |
3 | * | |
4 | * Copyright 2014 MundoReader S.L. | |
5 | * Copyright 2014 Google, Inc. | |
6 | * | |
7 | * This software is licensed under the terms of the GNU General Public | |
8 | * License version 2, as published by the Free Software Foundation, and | |
9 | * may be copied, distributed, and modified under those terms. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/mfd/syscon.h> | |
21 | #include <linux/of.h> | |
22 | #include <linux/platform_device.h> | |
23 | #include <linux/regmap.h> | |
24 | #include <linux/regulator/consumer.h> | |
25 | ||
26 | #define MAX_SUPPLIES 16 | |
27 | ||
28 | /* | |
29 | * The max voltage for 1.8V and 3.3V come from the Rockchip datasheet under | |
30 | * "Recommended Operating Conditions" for "Digital GPIO". When the typical | |
31 | * is 3.3V the max is 3.6V. When the typical is 1.8V the max is 1.98V. | |
32 | * | |
33 | * They are used like this: | |
34 | * - If the voltage on a rail is above the "1.8" voltage (1.98V) we'll tell the | |
35 | * SoC we're at 3.3. | |
36 | * - If the voltage on a rail is above the "3.3" voltage (3.6V) we'll consider | |
37 | * that to be an error. | |
38 | */ | |
39 | #define MAX_VOLTAGE_1_8 1980000 | |
40 | #define MAX_VOLTAGE_3_3 3600000 | |
41 | ||
42 | #define RK3288_SOC_CON2 0x24c | |
43 | #define RK3288_SOC_CON2_FLASH0 BIT(7) | |
44 | #define RK3288_SOC_FLASH_SUPPLY_NUM 2 | |
45 | ||
46 | struct rockchip_iodomain; | |
47 | ||
48 | /** | |
49 | * @supplies: voltage settings matching the register bits. | |
50 | */ | |
51 | struct rockchip_iodomain_soc_data { | |
52 | int grf_offset; | |
53 | const char *supply_names[MAX_SUPPLIES]; | |
54 | void (*init)(struct rockchip_iodomain *iod); | |
55 | }; | |
56 | ||
57 | struct rockchip_iodomain_supply { | |
58 | struct rockchip_iodomain *iod; | |
59 | struct regulator *reg; | |
60 | struct notifier_block nb; | |
61 | int idx; | |
62 | }; | |
63 | ||
64 | struct rockchip_iodomain { | |
65 | struct device *dev; | |
66 | struct regmap *grf; | |
67 | struct rockchip_iodomain_soc_data *soc_data; | |
68 | struct rockchip_iodomain_supply supplies[MAX_SUPPLIES]; | |
69 | }; | |
70 | ||
71 | static int rockchip_iodomain_write(struct rockchip_iodomain_supply *supply, | |
72 | int uV) | |
73 | { | |
74 | struct rockchip_iodomain *iod = supply->iod; | |
75 | u32 val; | |
76 | int ret; | |
77 | ||
78 | /* set value bit */ | |
79 | val = (uV > MAX_VOLTAGE_1_8) ? 0 : 1; | |
80 | val <<= supply->idx; | |
81 | ||
82 | /* apply hiword-mask */ | |
83 | val |= (BIT(supply->idx) << 16); | |
84 | ||
85 | ret = regmap_write(iod->grf, iod->soc_data->grf_offset, val); | |
86 | if (ret) | |
87 | dev_err(iod->dev, "Couldn't write to GRF\n"); | |
88 | ||
89 | return ret; | |
90 | } | |
91 | ||
92 | static int rockchip_iodomain_notify(struct notifier_block *nb, | |
93 | unsigned long event, | |
94 | void *data) | |
95 | { | |
96 | struct rockchip_iodomain_supply *supply = | |
97 | container_of(nb, struct rockchip_iodomain_supply, nb); | |
98 | int uV; | |
99 | int ret; | |
100 | ||
101 | /* | |
102 | * According to Rockchip it's important to keep the SoC IO domain | |
103 | * higher than (or equal to) the external voltage. That means we need | |
104 | * to change it before external voltage changes happen in the case | |
105 | * of an increase. | |
106 | * | |
107 | * Note that in the "pre" change we pick the max possible voltage that | |
108 | * the regulator might end up at (the client requests a range and we | |
109 | * don't know for certain the exact voltage). Right now we rely on the | |
110 | * slop in MAX_VOLTAGE_1_8 and MAX_VOLTAGE_3_3 to save us if clients | |
111 | * request something like a max of 3.6V when they really want 3.3V. | |
112 | * We could attempt to come up with better rules if this fails. | |
113 | */ | |
114 | if (event & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) { | |
115 | struct pre_voltage_change_data *pvc_data = data; | |
116 | ||
117 | uV = max_t(unsigned long, pvc_data->old_uV, pvc_data->max_uV); | |
118 | } else if (event & (REGULATOR_EVENT_VOLTAGE_CHANGE | | |
119 | REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE)) { | |
120 | uV = (unsigned long)data; | |
121 | } else { | |
122 | return NOTIFY_OK; | |
123 | } | |
124 | ||
125 | dev_dbg(supply->iod->dev, "Setting to %d\n", uV); | |
126 | ||
127 | if (uV > MAX_VOLTAGE_3_3) { | |
128 | dev_err(supply->iod->dev, "Voltage too high: %d\n", uV); | |
129 | ||
130 | if (event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) | |
131 | return NOTIFY_BAD; | |
132 | } | |
133 | ||
134 | ret = rockchip_iodomain_write(supply, uV); | |
135 | if (ret && event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) | |
136 | return NOTIFY_BAD; | |
137 | ||
138 | dev_info(supply->iod->dev, "Setting to %d done\n", uV); | |
139 | return NOTIFY_OK; | |
140 | } | |
141 | ||
142 | static void rk3288_iodomain_init(struct rockchip_iodomain *iod) | |
143 | { | |
144 | int ret; | |
145 | u32 val; | |
146 | ||
147 | /* if no flash supply we should leave things alone */ | |
148 | if (!iod->supplies[RK3288_SOC_FLASH_SUPPLY_NUM].reg) | |
149 | return; | |
150 | ||
151 | /* | |
152 | * set flash0 iodomain to also use this framework | |
153 | * instead of a special gpio. | |
154 | */ | |
155 | val = RK3288_SOC_CON2_FLASH0 | (RK3288_SOC_CON2_FLASH0 << 16); | |
156 | ret = regmap_write(iod->grf, RK3288_SOC_CON2, val); | |
157 | if (ret < 0) | |
158 | dev_warn(iod->dev, "couldn't update flash0 ctrl\n"); | |
159 | } | |
160 | ||
161 | /* | |
162 | * On the rk3188 the io-domains are handled by a shared register with the | |
163 | * lower 8 bits being still being continuing drive-strength settings. | |
164 | */ | |
165 | static const struct rockchip_iodomain_soc_data soc_data_rk3188 = { | |
166 | .grf_offset = 0x104, | |
167 | .supply_names = { | |
168 | NULL, | |
169 | NULL, | |
170 | NULL, | |
171 | NULL, | |
172 | NULL, | |
173 | NULL, | |
174 | NULL, | |
175 | NULL, | |
176 | "ap0", | |
177 | "ap1", | |
178 | "cif", | |
179 | "flash", | |
180 | "vccio0", | |
181 | "vccio1", | |
182 | "lcdc0", | |
183 | "lcdc1", | |
184 | }, | |
185 | }; | |
186 | ||
187 | static const struct rockchip_iodomain_soc_data soc_data_rk3288 = { | |
188 | .grf_offset = 0x380, | |
189 | .supply_names = { | |
190 | "lcdc", /* LCDC_VDD */ | |
191 | "dvp", /* DVPIO_VDD */ | |
192 | "flash0", /* FLASH0_VDD (emmc) */ | |
193 | "flash1", /* FLASH1_VDD (sdio1) */ | |
194 | "wifi", /* APIO3_VDD (sdio0) */ | |
195 | "bb", /* APIO5_VDD */ | |
196 | "audio", /* APIO4_VDD */ | |
197 | "sdcard", /* SDMMC0_VDD (sdmmc) */ | |
198 | "gpio30", /* APIO1_VDD */ | |
199 | "gpio1830", /* APIO2_VDD */ | |
200 | }, | |
201 | .init = rk3288_iodomain_init, | |
202 | }; | |
203 | ||
204 | static const struct of_device_id rockchip_iodomain_match[] = { | |
205 | { | |
206 | .compatible = "rockchip,rk3188-io-voltage-domain", | |
207 | .data = (void *)&soc_data_rk3188 | |
208 | }, | |
209 | { | |
210 | .compatible = "rockchip,rk3288-io-voltage-domain", | |
211 | .data = (void *)&soc_data_rk3288 | |
212 | }, | |
213 | { /* sentinel */ }, | |
214 | }; | |
215 | ||
216 | static int rockchip_iodomain_probe(struct platform_device *pdev) | |
217 | { | |
218 | struct device_node *np = pdev->dev.of_node; | |
219 | const struct of_device_id *match; | |
220 | struct rockchip_iodomain *iod; | |
221 | int i, ret = 0; | |
222 | ||
223 | if (!np) | |
224 | return -ENODEV; | |
225 | ||
226 | iod = devm_kzalloc(&pdev->dev, sizeof(*iod), GFP_KERNEL); | |
227 | if (!iod) | |
228 | return -ENOMEM; | |
229 | ||
230 | iod->dev = &pdev->dev; | |
231 | platform_set_drvdata(pdev, iod); | |
232 | ||
233 | match = of_match_node(rockchip_iodomain_match, np); | |
234 | iod->soc_data = (struct rockchip_iodomain_soc_data *)match->data; | |
235 | ||
236 | iod->grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf"); | |
237 | if (IS_ERR(iod->grf)) { | |
238 | dev_err(&pdev->dev, "couldn't find grf regmap\n"); | |
239 | return PTR_ERR(iod->grf); | |
240 | } | |
241 | ||
242 | for (i = 0; i < MAX_SUPPLIES; i++) { | |
243 | const char *supply_name = iod->soc_data->supply_names[i]; | |
244 | struct rockchip_iodomain_supply *supply = &iod->supplies[i]; | |
245 | struct regulator *reg; | |
246 | int uV; | |
247 | ||
248 | if (!supply_name) | |
249 | continue; | |
250 | ||
251 | reg = devm_regulator_get_optional(iod->dev, supply_name); | |
252 | if (IS_ERR(reg)) { | |
253 | ret = PTR_ERR(reg); | |
254 | ||
255 | /* If a supply wasn't specified, that's OK */ | |
256 | if (ret == -ENODEV) | |
257 | continue; | |
258 | else if (ret != -EPROBE_DEFER) | |
259 | dev_err(iod->dev, "couldn't get regulator %s\n", | |
260 | supply_name); | |
261 | goto unreg_notify; | |
262 | } | |
263 | ||
264 | /* set initial correct value */ | |
265 | uV = regulator_get_voltage(reg); | |
266 | ||
267 | /* must be a regulator we can get the voltage of */ | |
268 | if (uV < 0) { | |
269 | dev_err(iod->dev, "Can't determine voltage: %s\n", | |
270 | supply_name); | |
271 | goto unreg_notify; | |
272 | } | |
273 | ||
274 | if (uV > MAX_VOLTAGE_3_3) { | |
275 | dev_crit(iod->dev, | |
276 | "%d uV is too high. May damage SoC!\n", | |
277 | uV); | |
278 | ret = -EINVAL; | |
279 | goto unreg_notify; | |
280 | } | |
281 | ||
282 | /* setup our supply */ | |
283 | supply->idx = i; | |
284 | supply->iod = iod; | |
285 | supply->reg = reg; | |
286 | supply->nb.notifier_call = rockchip_iodomain_notify; | |
287 | ||
288 | ret = rockchip_iodomain_write(supply, uV); | |
289 | if (ret) { | |
290 | supply->reg = NULL; | |
291 | goto unreg_notify; | |
292 | } | |
293 | ||
294 | /* register regulator notifier */ | |
295 | ret = regulator_register_notifier(reg, &supply->nb); | |
296 | if (ret) { | |
297 | dev_err(&pdev->dev, | |
298 | "regulator notifier request failed\n"); | |
299 | supply->reg = NULL; | |
300 | goto unreg_notify; | |
301 | } | |
302 | } | |
303 | ||
304 | if (iod->soc_data->init) | |
305 | iod->soc_data->init(iod); | |
306 | ||
307 | return 0; | |
308 | ||
309 | unreg_notify: | |
310 | for (i = MAX_SUPPLIES - 1; i >= 0; i--) { | |
311 | struct rockchip_iodomain_supply *io_supply = &iod->supplies[i]; | |
312 | ||
313 | if (io_supply->reg) | |
314 | regulator_unregister_notifier(io_supply->reg, | |
315 | &io_supply->nb); | |
316 | } | |
317 | ||
318 | return ret; | |
319 | } | |
320 | ||
321 | static int rockchip_iodomain_remove(struct platform_device *pdev) | |
322 | { | |
323 | struct rockchip_iodomain *iod = platform_get_drvdata(pdev); | |
324 | int i; | |
325 | ||
326 | for (i = MAX_SUPPLIES - 1; i >= 0; i--) { | |
327 | struct rockchip_iodomain_supply *io_supply = &iod->supplies[i]; | |
328 | ||
329 | if (io_supply->reg) | |
330 | regulator_unregister_notifier(io_supply->reg, | |
331 | &io_supply->nb); | |
332 | } | |
333 | ||
334 | return 0; | |
335 | } | |
336 | ||
337 | static struct platform_driver rockchip_iodomain_driver = { | |
338 | .probe = rockchip_iodomain_probe, | |
339 | .remove = rockchip_iodomain_remove, | |
340 | .driver = { | |
341 | .name = "rockchip-iodomain", | |
342 | .of_match_table = rockchip_iodomain_match, | |
343 | }, | |
344 | }; | |
345 | ||
346 | module_platform_driver(rockchip_iodomain_driver); | |
347 | ||
348 | MODULE_DESCRIPTION("Rockchip IO-domain driver"); | |
349 | MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>"); | |
350 | MODULE_AUTHOR("Doug Anderson <dianders@chromium.org>"); | |
351 | MODULE_LICENSE("GPL v2"); |