diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/regulator/Kconfig | 7 | ||||
| -rw-r--r-- | drivers/regulator/Makefile | 1 | ||||
| -rw-r--r-- | drivers/regulator/vctrl-regulator.c | 546 |
3 files changed, 554 insertions, 0 deletions
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig index d54044c03a6c..48db87d6dfef 100644 --- a/drivers/regulator/Kconfig +++ b/drivers/regulator/Kconfig @@ -877,6 +877,13 @@ config REGULATOR_TWL4030 This driver supports the voltage regulators provided by this family of companion chips. +config REGULATOR_VCTRL + tristate "Voltage controlled regulators" + depends on OF + help + This driver provides support for voltage regulators whose output + voltage is controlled by the voltage of another regulator. + config REGULATOR_VEXPRESS tristate "Versatile Express regulators" depends on VEXPRESS_CONFIG diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile index f30cb0e2d6fb..dc3503fb3e30 100644 --- a/drivers/regulator/Makefile +++ b/drivers/regulator/Makefile @@ -109,6 +109,7 @@ obj-$(CONFIG_REGULATOR_TPS65912) += tps65912-regulator.o obj-$(CONFIG_REGULATOR_TPS80031) += tps80031-regulator.o obj-$(CONFIG_REGULATOR_TPS65132) += tps65132-regulator.o obj-$(CONFIG_REGULATOR_TWL4030) += twl-regulator.o twl6030-regulator.o +obj-$(CONFIG_REGULATOR_VCTRL) += vctrl-regulator.o obj-$(CONFIG_REGULATOR_VEXPRESS) += vexpress-regulator.o obj-$(CONFIG_REGULATOR_WM831X) += wm831x-dcdc.o obj-$(CONFIG_REGULATOR_WM831X) += wm831x-isink.o diff --git a/drivers/regulator/vctrl-regulator.c b/drivers/regulator/vctrl-regulator.c new file mode 100644 index 000000000000..78de002037c7 --- /dev/null +++ b/drivers/regulator/vctrl-regulator.c @@ -0,0 +1,546 @@ +/* + * Driver for voltage controller regulators + * + * Copyright (C) 2017 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/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--; + continue; + } + } + + 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"); |