2 * Rockchip IO Voltage Domain driver
4 * Copyright 2014 MundoReader S.L.
5 * Copyright 2014 Google, Inc.
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.
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.
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/err.h>
20 #include <linux/mfd/syscon.h>
22 #include <linux/platform_device.h>
23 #include <linux/regmap.h>
24 #include <linux/regulator/consumer.h>
26 #define MAX_SUPPLIES 16
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.
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
36 * - If the voltage on a rail is above the "3.3" voltage (3.6V) we'll consider
37 * that to be an error.
39 #define MAX_VOLTAGE_1_8 1980000
40 #define MAX_VOLTAGE_3_3 3600000
42 #define RK3288_SOC_CON2 0x24c
43 #define RK3288_SOC_CON2_FLASH0 BIT(7)
44 #define RK3288_SOC_FLASH_SUPPLY_NUM 2
46 struct rockchip_iodomain
;
49 * @supplies: voltage settings matching the register bits.
51 struct rockchip_iodomain_soc_data
{
53 const char *supply_names
[MAX_SUPPLIES
];
54 void (*init
)(struct rockchip_iodomain
*iod
);
57 struct rockchip_iodomain_supply
{
58 struct rockchip_iodomain
*iod
;
59 struct regulator
*reg
;
60 struct notifier_block nb
;
64 struct rockchip_iodomain
{
67 struct rockchip_iodomain_soc_data
*soc_data
;
68 struct rockchip_iodomain_supply supplies
[MAX_SUPPLIES
];
71 static int rockchip_iodomain_write(struct rockchip_iodomain_supply
*supply
,
74 struct rockchip_iodomain
*iod
= supply
->iod
;
79 val
= (uV
> MAX_VOLTAGE_1_8
) ? 0 : 1;
82 /* apply hiword-mask */
83 val
|= (BIT(supply
->idx
) << 16);
85 ret
= regmap_write(iod
->grf
, iod
->soc_data
->grf_offset
, val
);
87 dev_err(iod
->dev
, "Couldn't write to GRF\n");
92 static int rockchip_iodomain_notify(struct notifier_block
*nb
,
96 struct rockchip_iodomain_supply
*supply
=
97 container_of(nb
, struct rockchip_iodomain_supply
, nb
);
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
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.
114 if (event
& REGULATOR_EVENT_PRE_VOLTAGE_CHANGE
) {
115 struct pre_voltage_change_data
*pvc_data
= data
;
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
;
125 dev_dbg(supply
->iod
->dev
, "Setting to %d\n", uV
);
127 if (uV
> MAX_VOLTAGE_3_3
) {
128 dev_err(supply
->iod
->dev
, "Voltage too high: %d\n", uV
);
130 if (event
== REGULATOR_EVENT_PRE_VOLTAGE_CHANGE
)
134 ret
= rockchip_iodomain_write(supply
, uV
);
135 if (ret
&& event
== REGULATOR_EVENT_PRE_VOLTAGE_CHANGE
)
138 dev_info(supply
->iod
->dev
, "Setting to %d done\n", uV
);
142 static void rk3288_iodomain_init(struct rockchip_iodomain
*iod
)
147 /* if no flash supply we should leave things alone */
148 if (!iod
->supplies
[RK3288_SOC_FLASH_SUPPLY_NUM
].reg
)
152 * set flash0 iodomain to also use this framework
153 * instead of a special gpio.
155 val
= RK3288_SOC_CON2_FLASH0
| (RK3288_SOC_CON2_FLASH0
<< 16);
156 ret
= regmap_write(iod
->grf
, RK3288_SOC_CON2
, val
);
158 dev_warn(iod
->dev
, "couldn't update flash0 ctrl\n");
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.
165 static const struct rockchip_iodomain_soc_data soc_data_rk3188
= {
187 static const struct rockchip_iodomain_soc_data soc_data_rk3288
= {
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 */
201 .init
= rk3288_iodomain_init
,
204 static const struct of_device_id rockchip_iodomain_match
[] = {
206 .compatible
= "rockchip,rk3188-io-voltage-domain",
207 .data
= (void *)&soc_data_rk3188
210 .compatible
= "rockchip,rk3288-io-voltage-domain",
211 .data
= (void *)&soc_data_rk3288
216 static int rockchip_iodomain_probe(struct platform_device
*pdev
)
218 struct device_node
*np
= pdev
->dev
.of_node
;
219 const struct of_device_id
*match
;
220 struct rockchip_iodomain
*iod
;
226 iod
= devm_kzalloc(&pdev
->dev
, sizeof(*iod
), GFP_KERNEL
);
230 iod
->dev
= &pdev
->dev
;
231 platform_set_drvdata(pdev
, iod
);
233 match
= of_match_node(rockchip_iodomain_match
, np
);
234 iod
->soc_data
= (struct rockchip_iodomain_soc_data
*)match
->data
;
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
);
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
;
251 reg
= devm_regulator_get_optional(iod
->dev
, supply_name
);
255 /* If a supply wasn't specified, that's OK */
258 else if (ret
!= -EPROBE_DEFER
)
259 dev_err(iod
->dev
, "couldn't get regulator %s\n",
264 /* set initial correct value */
265 uV
= regulator_get_voltage(reg
);
267 /* must be a regulator we can get the voltage of */
269 dev_err(iod
->dev
, "Can't determine voltage: %s\n",
274 if (uV
> MAX_VOLTAGE_3_3
) {
276 "%d uV is too high. May damage SoC!\n",
282 /* setup our supply */
286 supply
->nb
.notifier_call
= rockchip_iodomain_notify
;
288 ret
= rockchip_iodomain_write(supply
, uV
);
294 /* register regulator notifier */
295 ret
= regulator_register_notifier(reg
, &supply
->nb
);
298 "regulator notifier request failed\n");
304 if (iod
->soc_data
->init
)
305 iod
->soc_data
->init(iod
);
310 for (i
= MAX_SUPPLIES
- 1; i
>= 0; i
--) {
311 struct rockchip_iodomain_supply
*io_supply
= &iod
->supplies
[i
];
314 regulator_unregister_notifier(io_supply
->reg
,
321 static int rockchip_iodomain_remove(struct platform_device
*pdev
)
323 struct rockchip_iodomain
*iod
= platform_get_drvdata(pdev
);
326 for (i
= MAX_SUPPLIES
- 1; i
>= 0; i
--) {
327 struct rockchip_iodomain_supply
*io_supply
= &iod
->supplies
[i
];
330 regulator_unregister_notifier(io_supply
->reg
,
337 static struct platform_driver rockchip_iodomain_driver
= {
338 .probe
= rockchip_iodomain_probe
,
339 .remove
= rockchip_iodomain_remove
,
341 .name
= "rockchip-iodomain",
342 .of_match_table
= rockchip_iodomain_match
,
346 module_platform_driver(rockchip_iodomain_driver
);
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");