351 lines
8.8 KiB
C
351 lines
8.8 KiB
C
/*
|
|
* Rockchip IO Voltage Domain driver
|
|
*
|
|
* Copyright 2014 MundoReader S.L.
|
|
* Copyright 2014 Google, Inc.
|
|
*
|
|
* This software is licensed under the terms of the GNU General Public
|
|
* License version 2, as published by the Free Software Foundation, and
|
|
* may be copied, distributed, and modified under those terms.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/err.h>
|
|
#include <linux/mfd/syscon.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/regmap.h>
|
|
#include <linux/regulator/consumer.h>
|
|
|
|
#define MAX_SUPPLIES 16
|
|
|
|
/*
|
|
* The max voltage for 1.8V and 3.3V come from the Rockchip datasheet under
|
|
* "Recommended Operating Conditions" for "Digital GPIO". When the typical
|
|
* is 3.3V the max is 3.6V. When the typical is 1.8V the max is 1.98V.
|
|
*
|
|
* They are used like this:
|
|
* - If the voltage on a rail is above the "1.8" voltage (1.98V) we'll tell the
|
|
* SoC we're at 3.3.
|
|
* - If the voltage on a rail is above the "3.3" voltage (3.6V) we'll consider
|
|
* that to be an error.
|
|
*/
|
|
#define MAX_VOLTAGE_1_8 1980000
|
|
#define MAX_VOLTAGE_3_3 3600000
|
|
|
|
#define RK3288_SOC_CON2 0x24c
|
|
#define RK3288_SOC_CON2_FLASH0 BIT(7)
|
|
#define RK3288_SOC_FLASH_SUPPLY_NUM 2
|
|
|
|
struct rockchip_iodomain;
|
|
|
|
/**
|
|
* @supplies: voltage settings matching the register bits.
|
|
*/
|
|
struct rockchip_iodomain_soc_data {
|
|
int grf_offset;
|
|
const char *supply_names[MAX_SUPPLIES];
|
|
void (*init)(struct rockchip_iodomain *iod);
|
|
};
|
|
|
|
struct rockchip_iodomain_supply {
|
|
struct rockchip_iodomain *iod;
|
|
struct regulator *reg;
|
|
struct notifier_block nb;
|
|
int idx;
|
|
};
|
|
|
|
struct rockchip_iodomain {
|
|
struct device *dev;
|
|
struct regmap *grf;
|
|
struct rockchip_iodomain_soc_data *soc_data;
|
|
struct rockchip_iodomain_supply supplies[MAX_SUPPLIES];
|
|
};
|
|
|
|
static int rockchip_iodomain_write(struct rockchip_iodomain_supply *supply,
|
|
int uV)
|
|
{
|
|
struct rockchip_iodomain *iod = supply->iod;
|
|
u32 val;
|
|
int ret;
|
|
|
|
/* set value bit */
|
|
val = (uV > MAX_VOLTAGE_1_8) ? 0 : 1;
|
|
val <<= supply->idx;
|
|
|
|
/* apply hiword-mask */
|
|
val |= (BIT(supply->idx) << 16);
|
|
|
|
ret = regmap_write(iod->grf, iod->soc_data->grf_offset, val);
|
|
if (ret)
|
|
dev_err(iod->dev, "Couldn't write to GRF\n");
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int rockchip_iodomain_notify(struct notifier_block *nb,
|
|
unsigned long event,
|
|
void *data)
|
|
{
|
|
struct rockchip_iodomain_supply *supply =
|
|
container_of(nb, struct rockchip_iodomain_supply, nb);
|
|
int uV;
|
|
int ret;
|
|
|
|
/*
|
|
* According to Rockchip it's important to keep the SoC IO domain
|
|
* higher than (or equal to) the external voltage. That means we need
|
|
* to change it before external voltage changes happen in the case
|
|
* of an increase.
|
|
*
|
|
* Note that in the "pre" change we pick the max possible voltage that
|
|
* the regulator might end up at (the client requests a range and we
|
|
* don't know for certain the exact voltage). Right now we rely on the
|
|
* slop in MAX_VOLTAGE_1_8 and MAX_VOLTAGE_3_3 to save us if clients
|
|
* request something like a max of 3.6V when they really want 3.3V.
|
|
* We could attempt to come up with better rules if this fails.
|
|
*/
|
|
if (event & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) {
|
|
struct pre_voltage_change_data *pvc_data = data;
|
|
|
|
uV = max_t(unsigned long, pvc_data->old_uV, pvc_data->max_uV);
|
|
} else if (event & (REGULATOR_EVENT_VOLTAGE_CHANGE |
|
|
REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE)) {
|
|
uV = (unsigned long)data;
|
|
} else {
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
dev_dbg(supply->iod->dev, "Setting to %d\n", uV);
|
|
|
|
if (uV > MAX_VOLTAGE_3_3) {
|
|
dev_err(supply->iod->dev, "Voltage too high: %d\n", uV);
|
|
|
|
if (event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
|
|
return NOTIFY_BAD;
|
|
}
|
|
|
|
ret = rockchip_iodomain_write(supply, uV);
|
|
if (ret && event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
|
|
return NOTIFY_BAD;
|
|
|
|
dev_info(supply->iod->dev, "Setting to %d done\n", uV);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static void rk3288_iodomain_init(struct rockchip_iodomain *iod)
|
|
{
|
|
int ret;
|
|
u32 val;
|
|
|
|
/* if no flash supply we should leave things alone */
|
|
if (!iod->supplies[RK3288_SOC_FLASH_SUPPLY_NUM].reg)
|
|
return;
|
|
|
|
/*
|
|
* set flash0 iodomain to also use this framework
|
|
* instead of a special gpio.
|
|
*/
|
|
val = RK3288_SOC_CON2_FLASH0 | (RK3288_SOC_CON2_FLASH0 << 16);
|
|
ret = regmap_write(iod->grf, RK3288_SOC_CON2, val);
|
|
if (ret < 0)
|
|
dev_warn(iod->dev, "couldn't update flash0 ctrl\n");
|
|
}
|
|
|
|
/*
|
|
* On the rk3188 the io-domains are handled by a shared register with the
|
|
* lower 8 bits being still being continuing drive-strength settings.
|
|
*/
|
|
static const struct rockchip_iodomain_soc_data soc_data_rk3188 = {
|
|
.grf_offset = 0x104,
|
|
.supply_names = {
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
"ap0",
|
|
"ap1",
|
|
"cif",
|
|
"flash",
|
|
"vccio0",
|
|
"vccio1",
|
|
"lcdc0",
|
|
"lcdc1",
|
|
},
|
|
};
|
|
|
|
static const struct rockchip_iodomain_soc_data soc_data_rk3288 = {
|
|
.grf_offset = 0x380,
|
|
.supply_names = {
|
|
"lcdc", /* LCDC_VDD */
|
|
"dvp", /* DVPIO_VDD */
|
|
"flash0", /* FLASH0_VDD (emmc) */
|
|
"flash1", /* FLASH1_VDD (sdio1) */
|
|
"wifi", /* APIO3_VDD (sdio0) */
|
|
"bb", /* APIO5_VDD */
|
|
"audio", /* APIO4_VDD */
|
|
"sdcard", /* SDMMC0_VDD (sdmmc) */
|
|
"gpio30", /* APIO1_VDD */
|
|
"gpio1830", /* APIO2_VDD */
|
|
},
|
|
.init = rk3288_iodomain_init,
|
|
};
|
|
|
|
static const struct of_device_id rockchip_iodomain_match[] = {
|
|
{
|
|
.compatible = "rockchip,rk3188-io-voltage-domain",
|
|
.data = (void *)&soc_data_rk3188
|
|
},
|
|
{
|
|
.compatible = "rockchip,rk3288-io-voltage-domain",
|
|
.data = (void *)&soc_data_rk3288
|
|
},
|
|
{ /* sentinel */ },
|
|
};
|
|
|
|
static int rockchip_iodomain_probe(struct platform_device *pdev)
|
|
{
|
|
struct device_node *np = pdev->dev.of_node;
|
|
const struct of_device_id *match;
|
|
struct rockchip_iodomain *iod;
|
|
int i, ret = 0;
|
|
|
|
if (!np)
|
|
return -ENODEV;
|
|
|
|
iod = devm_kzalloc(&pdev->dev, sizeof(*iod), GFP_KERNEL);
|
|
if (!iod)
|
|
return -ENOMEM;
|
|
|
|
iod->dev = &pdev->dev;
|
|
platform_set_drvdata(pdev, iod);
|
|
|
|
match = of_match_node(rockchip_iodomain_match, np);
|
|
iod->soc_data = (struct rockchip_iodomain_soc_data *)match->data;
|
|
|
|
iod->grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
|
|
if (IS_ERR(iod->grf)) {
|
|
dev_err(&pdev->dev, "couldn't find grf regmap\n");
|
|
return PTR_ERR(iod->grf);
|
|
}
|
|
|
|
for (i = 0; i < MAX_SUPPLIES; i++) {
|
|
const char *supply_name = iod->soc_data->supply_names[i];
|
|
struct rockchip_iodomain_supply *supply = &iod->supplies[i];
|
|
struct regulator *reg;
|
|
int uV;
|
|
|
|
if (!supply_name)
|
|
continue;
|
|
|
|
reg = devm_regulator_get_optional(iod->dev, supply_name);
|
|
if (IS_ERR(reg)) {
|
|
ret = PTR_ERR(reg);
|
|
|
|
/* If a supply wasn't specified, that's OK */
|
|
if (ret == -ENODEV)
|
|
continue;
|
|
else if (ret != -EPROBE_DEFER)
|
|
dev_err(iod->dev, "couldn't get regulator %s\n",
|
|
supply_name);
|
|
goto unreg_notify;
|
|
}
|
|
|
|
/* set initial correct value */
|
|
uV = regulator_get_voltage(reg);
|
|
|
|
/* must be a regulator we can get the voltage of */
|
|
if (uV < 0) {
|
|
dev_err(iod->dev, "Can't determine voltage: %s\n",
|
|
supply_name);
|
|
goto unreg_notify;
|
|
}
|
|
|
|
if (uV > MAX_VOLTAGE_3_3) {
|
|
dev_crit(iod->dev,
|
|
"%d uV is too high. May damage SoC!\n",
|
|
uV);
|
|
ret = -EINVAL;
|
|
goto unreg_notify;
|
|
}
|
|
|
|
/* setup our supply */
|
|
supply->idx = i;
|
|
supply->iod = iod;
|
|
supply->reg = reg;
|
|
supply->nb.notifier_call = rockchip_iodomain_notify;
|
|
|
|
ret = rockchip_iodomain_write(supply, uV);
|
|
if (ret) {
|
|
supply->reg = NULL;
|
|
goto unreg_notify;
|
|
}
|
|
|
|
/* register regulator notifier */
|
|
ret = regulator_register_notifier(reg, &supply->nb);
|
|
if (ret) {
|
|
dev_err(&pdev->dev,
|
|
"regulator notifier request failed\n");
|
|
supply->reg = NULL;
|
|
goto unreg_notify;
|
|
}
|
|
}
|
|
|
|
if (iod->soc_data->init)
|
|
iod->soc_data->init(iod);
|
|
|
|
return 0;
|
|
|
|
unreg_notify:
|
|
for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
|
|
struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];
|
|
|
|
if (io_supply->reg)
|
|
regulator_unregister_notifier(io_supply->reg,
|
|
&io_supply->nb);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int rockchip_iodomain_remove(struct platform_device *pdev)
|
|
{
|
|
struct rockchip_iodomain *iod = platform_get_drvdata(pdev);
|
|
int i;
|
|
|
|
for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
|
|
struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];
|
|
|
|
if (io_supply->reg)
|
|
regulator_unregister_notifier(io_supply->reg,
|
|
&io_supply->nb);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver rockchip_iodomain_driver = {
|
|
.probe = rockchip_iodomain_probe,
|
|
.remove = rockchip_iodomain_remove,
|
|
.driver = {
|
|
.name = "rockchip-iodomain",
|
|
.of_match_table = rockchip_iodomain_match,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(rockchip_iodomain_driver);
|
|
|
|
MODULE_DESCRIPTION("Rockchip IO-domain driver");
|
|
MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
|
|
MODULE_AUTHOR("Doug Anderson <dianders@chromium.org>");
|
|
MODULE_LICENSE("GPL v2");
|