linux/drivers/regulator/vctrl-regulator.c
Thomas Gleixner 9c92ab6191 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00

537 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for voltage controller regulators
*
* Copyright (C) 2017 Google, Inc.
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>
#include <linux/sort.h>
struct vctrl_voltage_range {
int min_uV;
int max_uV;
};
struct vctrl_voltage_ranges {
struct vctrl_voltage_range ctrl;
struct vctrl_voltage_range out;
};
struct vctrl_voltage_table {
int ctrl;
int out;
int ovp_min_sel;
};
struct vctrl_data {
struct regulator_dev *rdev;
struct regulator_desc desc;
struct regulator *ctrl_reg;
bool enabled;
unsigned int min_slew_down_rate;
unsigned int ovp_threshold;
struct vctrl_voltage_ranges vrange;
struct vctrl_voltage_table *vtable;
unsigned int sel;
};
static int vctrl_calc_ctrl_voltage(struct vctrl_data *vctrl, int out_uV)
{
struct vctrl_voltage_range *ctrl = &vctrl->vrange.ctrl;
struct vctrl_voltage_range *out = &vctrl->vrange.out;
return ctrl->min_uV +
DIV_ROUND_CLOSEST_ULL((s64)(out_uV - out->min_uV) *
(ctrl->max_uV - ctrl->min_uV),
out->max_uV - out->min_uV);
}
static int vctrl_calc_output_voltage(struct vctrl_data *vctrl, int ctrl_uV)
{
struct vctrl_voltage_range *ctrl = &vctrl->vrange.ctrl;
struct vctrl_voltage_range *out = &vctrl->vrange.out;
if (ctrl_uV < 0) {
pr_err("vctrl: failed to get control voltage\n");
return ctrl_uV;
}
if (ctrl_uV < ctrl->min_uV)
return out->min_uV;
if (ctrl_uV > ctrl->max_uV)
return out->max_uV;
return out->min_uV +
DIV_ROUND_CLOSEST_ULL((s64)(ctrl_uV - ctrl->min_uV) *
(out->max_uV - out->min_uV),
ctrl->max_uV - ctrl->min_uV);
}
static int vctrl_get_voltage(struct regulator_dev *rdev)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
int ctrl_uV = regulator_get_voltage(vctrl->ctrl_reg);
return vctrl_calc_output_voltage(vctrl, ctrl_uV);
}
static int vctrl_set_voltage(struct regulator_dev *rdev,
int req_min_uV, int req_max_uV,
unsigned int *selector)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
struct regulator *ctrl_reg = vctrl->ctrl_reg;
int orig_ctrl_uV = regulator_get_voltage(ctrl_reg);
int uV = vctrl_calc_output_voltage(vctrl, orig_ctrl_uV);
int ret;
if (req_min_uV >= uV || !vctrl->ovp_threshold)
/* voltage rising or no OVP */
return regulator_set_voltage(
ctrl_reg,
vctrl_calc_ctrl_voltage(vctrl, req_min_uV),
vctrl_calc_ctrl_voltage(vctrl, req_max_uV));
while (uV > req_min_uV) {
int max_drop_uV = (uV * vctrl->ovp_threshold) / 100;
int next_uV;
int next_ctrl_uV;
int delay;
/* Make sure no infinite loop even in crazy cases */
if (max_drop_uV == 0)
max_drop_uV = 1;
next_uV = max_t(int, req_min_uV, uV - max_drop_uV);
next_ctrl_uV = vctrl_calc_ctrl_voltage(vctrl, next_uV);
ret = regulator_set_voltage(ctrl_reg,
next_ctrl_uV,
next_ctrl_uV);
if (ret)
goto err;
delay = DIV_ROUND_UP(uV - next_uV, vctrl->min_slew_down_rate);
usleep_range(delay, delay + DIV_ROUND_UP(delay, 10));
uV = next_uV;
}
return 0;
err:
/* Try to go back to original voltage */
regulator_set_voltage(ctrl_reg, orig_ctrl_uV, orig_ctrl_uV);
return ret;
}
static int vctrl_get_voltage_sel(struct regulator_dev *rdev)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
return vctrl->sel;
}
static int vctrl_set_voltage_sel(struct regulator_dev *rdev,
unsigned int selector)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
struct regulator *ctrl_reg = vctrl->ctrl_reg;
unsigned int orig_sel = vctrl->sel;
int ret;
if (selector >= rdev->desc->n_voltages)
return -EINVAL;
if (selector >= vctrl->sel || !vctrl->ovp_threshold) {
/* voltage rising or no OVP */
ret = regulator_set_voltage(ctrl_reg,
vctrl->vtable[selector].ctrl,
vctrl->vtable[selector].ctrl);
if (!ret)
vctrl->sel = selector;
return ret;
}
while (vctrl->sel != selector) {
unsigned int next_sel;
int delay;
if (selector >= vctrl->vtable[vctrl->sel].ovp_min_sel)
next_sel = selector;
else
next_sel = vctrl->vtable[vctrl->sel].ovp_min_sel;
ret = regulator_set_voltage(ctrl_reg,
vctrl->vtable[next_sel].ctrl,
vctrl->vtable[next_sel].ctrl);
if (ret) {
dev_err(&rdev->dev,
"failed to set control voltage to %duV\n",
vctrl->vtable[next_sel].ctrl);
goto err;
}
vctrl->sel = next_sel;
delay = DIV_ROUND_UP(vctrl->vtable[vctrl->sel].out -
vctrl->vtable[next_sel].out,
vctrl->min_slew_down_rate);
usleep_range(delay, delay + DIV_ROUND_UP(delay, 10));
}
return 0;
err:
if (vctrl->sel != orig_sel) {
/* Try to go back to original voltage */
if (!regulator_set_voltage(ctrl_reg,
vctrl->vtable[orig_sel].ctrl,
vctrl->vtable[orig_sel].ctrl))
vctrl->sel = orig_sel;
else
dev_warn(&rdev->dev,
"failed to restore original voltage\n");
}
return ret;
}
static int vctrl_list_voltage(struct regulator_dev *rdev,
unsigned int selector)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
if (selector >= rdev->desc->n_voltages)
return -EINVAL;
return vctrl->vtable[selector].out;
}
static int vctrl_parse_dt(struct platform_device *pdev,
struct vctrl_data *vctrl)
{
int ret;
struct device_node *np = pdev->dev.of_node;
u32 pval;
u32 vrange_ctrl[2];
vctrl->ctrl_reg = devm_regulator_get(&pdev->dev, "ctrl");
if (IS_ERR(vctrl->ctrl_reg))
return PTR_ERR(vctrl->ctrl_reg);
ret = of_property_read_u32(np, "ovp-threshold-percent", &pval);
if (!ret) {
vctrl->ovp_threshold = pval;
if (vctrl->ovp_threshold > 100) {
dev_err(&pdev->dev,
"ovp-threshold-percent (%u) > 100\n",
vctrl->ovp_threshold);
return -EINVAL;
}
}
ret = of_property_read_u32(np, "min-slew-down-rate", &pval);
if (!ret) {
vctrl->min_slew_down_rate = pval;
/* We use the value as int and as divider; sanity check */
if (vctrl->min_slew_down_rate == 0) {
dev_err(&pdev->dev,
"min-slew-down-rate must not be 0\n");
return -EINVAL;
} else if (vctrl->min_slew_down_rate > INT_MAX) {
dev_err(&pdev->dev, "min-slew-down-rate (%u) too big\n",
vctrl->min_slew_down_rate);
return -EINVAL;
}
}
if (vctrl->ovp_threshold && !vctrl->min_slew_down_rate) {
dev_err(&pdev->dev,
"ovp-threshold-percent requires min-slew-down-rate\n");
return -EINVAL;
}
ret = of_property_read_u32(np, "regulator-min-microvolt", &pval);
if (ret) {
dev_err(&pdev->dev,
"failed to read regulator-min-microvolt: %d\n", ret);
return ret;
}
vctrl->vrange.out.min_uV = pval;
ret = of_property_read_u32(np, "regulator-max-microvolt", &pval);
if (ret) {
dev_err(&pdev->dev,
"failed to read regulator-max-microvolt: %d\n", ret);
return ret;
}
vctrl->vrange.out.max_uV = pval;
ret = of_property_read_u32_array(np, "ctrl-voltage-range", vrange_ctrl,
2);
if (ret) {
dev_err(&pdev->dev, "failed to read ctrl-voltage-range: %d\n",
ret);
return ret;
}
if (vrange_ctrl[0] >= vrange_ctrl[1]) {
dev_err(&pdev->dev, "ctrl-voltage-range is invalid: %d-%d\n",
vrange_ctrl[0], vrange_ctrl[1]);
return -EINVAL;
}
vctrl->vrange.ctrl.min_uV = vrange_ctrl[0];
vctrl->vrange.ctrl.max_uV = vrange_ctrl[1];
return 0;
}
static int vctrl_cmp_ctrl_uV(const void *a, const void *b)
{
const struct vctrl_voltage_table *at = a;
const struct vctrl_voltage_table *bt = b;
return at->ctrl - bt->ctrl;
}
static int vctrl_init_vtable(struct platform_device *pdev)
{
struct vctrl_data *vctrl = platform_get_drvdata(pdev);
struct regulator_desc *rdesc = &vctrl->desc;
struct regulator *ctrl_reg = vctrl->ctrl_reg;
struct vctrl_voltage_range *vrange_ctrl = &vctrl->vrange.ctrl;
int n_voltages;
int ctrl_uV;
int i, idx_vt;
n_voltages = regulator_count_voltages(ctrl_reg);
rdesc->n_voltages = n_voltages;
/* determine number of steps within the range of the vctrl regulator */
for (i = 0; i < n_voltages; i++) {
ctrl_uV = regulator_list_voltage(ctrl_reg, i);
if (ctrl_uV < vrange_ctrl->min_uV ||
ctrl_uV > vrange_ctrl->max_uV)
rdesc->n_voltages--;
}
if (rdesc->n_voltages == 0) {
dev_err(&pdev->dev, "invalid configuration\n");
return -EINVAL;
}
vctrl->vtable = devm_kcalloc(&pdev->dev, rdesc->n_voltages,
sizeof(struct vctrl_voltage_table),
GFP_KERNEL);
if (!vctrl->vtable)
return -ENOMEM;
/* create mapping control <=> output voltage */
for (i = 0, idx_vt = 0; i < n_voltages; i++) {
ctrl_uV = regulator_list_voltage(ctrl_reg, i);
if (ctrl_uV < vrange_ctrl->min_uV ||
ctrl_uV > vrange_ctrl->max_uV)
continue;
vctrl->vtable[idx_vt].ctrl = ctrl_uV;
vctrl->vtable[idx_vt].out =
vctrl_calc_output_voltage(vctrl, ctrl_uV);
idx_vt++;
}
/* we rely on the table to be ordered by ascending voltage */
sort(vctrl->vtable, rdesc->n_voltages,
sizeof(struct vctrl_voltage_table), vctrl_cmp_ctrl_uV,
NULL);
/* pre-calculate OVP-safe downward transitions */
for (i = rdesc->n_voltages - 1; i > 0; i--) {
int j;
int ovp_min_uV = (vctrl->vtable[i].out *
(100 - vctrl->ovp_threshold)) / 100;
for (j = 0; j < i; j++) {
if (vctrl->vtable[j].out >= ovp_min_uV) {
vctrl->vtable[i].ovp_min_sel = j;
break;
}
}
if (j == i) {
dev_warn(&pdev->dev, "switching down from %duV may cause OVP shutdown\n",
vctrl->vtable[i].out);
/* use next lowest voltage */
vctrl->vtable[i].ovp_min_sel = i - 1;
}
}
return 0;
}
static int vctrl_enable(struct regulator_dev *rdev)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
int ret = regulator_enable(vctrl->ctrl_reg);
if (!ret)
vctrl->enabled = true;
return ret;
}
static int vctrl_disable(struct regulator_dev *rdev)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
int ret = regulator_disable(vctrl->ctrl_reg);
if (!ret)
vctrl->enabled = false;
return ret;
}
static int vctrl_is_enabled(struct regulator_dev *rdev)
{
struct vctrl_data *vctrl = rdev_get_drvdata(rdev);
return vctrl->enabled;
}
static const struct regulator_ops vctrl_ops_cont = {
.enable = vctrl_enable,
.disable = vctrl_disable,
.is_enabled = vctrl_is_enabled,
.get_voltage = vctrl_get_voltage,
.set_voltage = vctrl_set_voltage,
};
static const struct regulator_ops vctrl_ops_non_cont = {
.enable = vctrl_enable,
.disable = vctrl_disable,
.is_enabled = vctrl_is_enabled,
.set_voltage_sel = vctrl_set_voltage_sel,
.get_voltage_sel = vctrl_get_voltage_sel,
.list_voltage = vctrl_list_voltage,
.map_voltage = regulator_map_voltage_iterate,
};
static int vctrl_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct vctrl_data *vctrl;
const struct regulator_init_data *init_data;
struct regulator_desc *rdesc;
struct regulator_config cfg = { };
struct vctrl_voltage_range *vrange_ctrl;
int ctrl_uV;
int ret;
vctrl = devm_kzalloc(&pdev->dev, sizeof(struct vctrl_data),
GFP_KERNEL);
if (!vctrl)
return -ENOMEM;
platform_set_drvdata(pdev, vctrl);
ret = vctrl_parse_dt(pdev, vctrl);
if (ret)
return ret;
vrange_ctrl = &vctrl->vrange.ctrl;
rdesc = &vctrl->desc;
rdesc->name = "vctrl";
rdesc->type = REGULATOR_VOLTAGE;
rdesc->owner = THIS_MODULE;
if ((regulator_get_linear_step(vctrl->ctrl_reg) == 1) ||
(regulator_count_voltages(vctrl->ctrl_reg) == -EINVAL)) {
rdesc->continuous_voltage_range = true;
rdesc->ops = &vctrl_ops_cont;
} else {
rdesc->ops = &vctrl_ops_non_cont;
}
init_data = of_get_regulator_init_data(&pdev->dev, np, rdesc);
if (!init_data)
return -ENOMEM;
cfg.of_node = np;
cfg.dev = &pdev->dev;
cfg.driver_data = vctrl;
cfg.init_data = init_data;
if (!rdesc->continuous_voltage_range) {
ret = vctrl_init_vtable(pdev);
if (ret)
return ret;
ctrl_uV = regulator_get_voltage(vctrl->ctrl_reg);
if (ctrl_uV < 0) {
dev_err(&pdev->dev, "failed to get control voltage\n");
return ctrl_uV;
}
/* determine current voltage selector from control voltage */
if (ctrl_uV < vrange_ctrl->min_uV) {
vctrl->sel = 0;
} else if (ctrl_uV > vrange_ctrl->max_uV) {
vctrl->sel = rdesc->n_voltages - 1;
} else {
int i;
for (i = 0; i < rdesc->n_voltages; i++) {
if (ctrl_uV == vctrl->vtable[i].ctrl) {
vctrl->sel = i;
break;
}
}
}
}
vctrl->rdev = devm_regulator_register(&pdev->dev, rdesc, &cfg);
if (IS_ERR(vctrl->rdev)) {
ret = PTR_ERR(vctrl->rdev);
dev_err(&pdev->dev, "failed to register regulator: %d\n", ret);
return ret;
}
return 0;
}
static const struct of_device_id vctrl_of_match[] = {
{ .compatible = "vctrl-regulator", },
{},
};
MODULE_DEVICE_TABLE(of, vctrl_of_match);
static struct platform_driver vctrl_driver = {
.probe = vctrl_probe,
.driver = {
.name = "vctrl-regulator",
.of_match_table = of_match_ptr(vctrl_of_match),
},
};
module_platform_driver(vctrl_driver);
MODULE_DESCRIPTION("Voltage Controlled Regulator Driver");
MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
MODULE_LICENSE("GPL v2");