diff options
Diffstat (limited to 'drivers/power/regulator/pwm_regulator.c')
| -rw-r--r-- | drivers/power/regulator/pwm_regulator.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/power/regulator/pwm_regulator.c b/drivers/power/regulator/pwm_regulator.c new file mode 100644 index 0000000000..b0a4c5da6d --- /dev/null +++ b/drivers/power/regulator/pwm_regulator.c @@ -0,0 +1,159 @@ +/* + * Copyright (C) 2016 Rockchip Electronics Co., Ltd + * + * Based on kernel drivers/regulator/pwm-regulator.c + * Copyright (C) 2014 - STMicroelectronics Inc. + * Author: Lee Jones <lee.jones@linaro.org> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <pwm.h> +#include <power/regulator.h> +#include <libfdt.h> +#include <fdt_support.h> +#include <fdtdec.h> + +DECLARE_GLOBAL_DATA_PTR; + +struct pwm_regulator_info { + /* pwm id corresponding to the PWM driver */ + int pwm_id; + /* the period of one PWM cycle */ + int period_ns; + struct udevice *pwm; + /* initialize voltage of regulator */ + unsigned int init_voltage; + /* the maximum voltage of regulator */ + unsigned int max_voltage; + /* the minimum voltage of regulator */ + unsigned int min_voltage; + /* the current voltage of regulator */ + unsigned int volt_uV; +}; + +static int pwm_regulator_enable(struct udevice *dev, bool enable) +{ + struct pwm_regulator_info *priv = dev_get_priv(dev); + + return pwm_set_enable(priv->pwm, priv->pwm_id, enable); +} + +static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV) +{ + struct pwm_regulator_info *priv = dev_get_priv(dev); + int min_uV = priv->min_voltage; + int max_uV = priv->max_voltage; + int diff = max_uV - min_uV; + + return 100 - (((req_uV * 100) - (min_uV * 100)) / diff); +} + +static int pwm_regulator_get_voltage(struct udevice *dev) +{ + struct pwm_regulator_info *priv = dev_get_priv(dev); + + return priv->volt_uV; +} + +static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt) +{ + struct pwm_regulator_info *priv = dev_get_priv(dev); + int duty_cycle; + int ret = 0; + + duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt); + + ret = pwm_set_config(priv->pwm, priv->pwm_id, + (priv->period_ns / 100) * duty_cycle, priv->period_ns); + if (ret) { + dev_err(dev, "Failed to configure PWM\n"); + return ret; + } + + ret = pwm_set_enable(priv->pwm, priv->pwm_id, true); + if (ret) { + dev_err(dev, "Failed to enable PWM\n"); + return ret; + } + priv->volt_uV = uvolt; + return ret; +} + +static int pwm_regulator_ofdata_to_platdata(struct udevice *dev) +{ + struct pwm_regulator_info *priv = dev_get_priv(dev); + struct fdtdec_phandle_args args; + const void *blob = gd->fdt_blob; + int node = dev->of_offset; + int ret; + + ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells", + 0, 0, &args); + if (ret) { + debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); + return ret; + } + /* TODO: pwm_id here from device tree if needed */ + + priv->period_ns = args.args[1]; + + priv->init_voltage = fdtdec_get_int(blob, node, + "regulator-init-microvolt", -1); + if (priv->init_voltage < 0) { + printf("Cannot find regulator pwm init_voltage\n"); + return -EINVAL; + } + + ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm); + if (ret) { + debug("%s: Cannot get PWM: ret=%d\n", __func__, ret); + return ret; + } + + return 0; +} + +static int pwm_regulator_probe(struct udevice *dev) +{ + struct pwm_regulator_info *priv = dev_get_priv(dev); + struct dm_regulator_uclass_platdata *uc_pdata; + + uc_pdata = dev_get_uclass_platdata(dev); + + uc_pdata->type = REGULATOR_TYPE_BUCK; + uc_pdata->mode_count = 0; + priv->max_voltage = uc_pdata->max_uV; + priv->min_voltage = uc_pdata->min_uV; + + if (priv->init_voltage) + pwm_regulator_set_voltage(dev, priv->init_voltage); + + pwm_regulator_enable(dev, 1); + + return 0; +} + +static const struct dm_regulator_ops pwm_regulator_ops = { + .get_value = pwm_regulator_get_voltage, + .set_value = pwm_regulator_set_voltage, + .set_enable = pwm_regulator_enable, +}; + +static const struct udevice_id pwm_regulator_ids[] = { + { .compatible = "pwm-regulator" }, + { } +}; + +U_BOOT_DRIVER(pwm_regulator) = { + .name = "pwm_regulator", + .id = UCLASS_REGULATOR, + .ops = &pwm_regulator_ops, + .probe = pwm_regulator_probe, + .of_match = pwm_regulator_ids, + .ofdata_to_platdata = pwm_regulator_ofdata_to_platdata, + .priv_auto_alloc_size = sizeof(struct pwm_regulator_info), +}; |