354 lines
7.6 KiB
C
354 lines
7.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* PWM Greybus driver.
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*
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* Copyright 2014 Google Inc.
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* Copyright 2014 Linaro Ltd.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/pwm.h>
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#include <linux/greybus.h>
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#include "gbphy.h"
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struct gb_pwm_chip {
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struct gb_connection *connection;
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u8 pwm_max; /* max pwm number */
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struct pwm_chip chip;
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struct pwm_chip *pwm;
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};
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static inline struct gb_pwm_chip *pwm_chip_to_gb_pwm_chip(struct pwm_chip *chip)
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{
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return container_of(chip, struct gb_pwm_chip, chip);
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}
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static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
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{
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struct gb_pwm_count_response response;
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int ret;
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ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
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NULL, 0, &response, sizeof(response));
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if (ret)
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return ret;
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pwmc->pwm_max = response.count;
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return 0;
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}
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static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
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u8 which)
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{
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struct gb_pwm_activate_request request;
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struct gbphy_device *gbphy_dev;
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int ret;
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if (which > pwmc->pwm_max)
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return -EINVAL;
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request.which = which;
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gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
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ret = gbphy_runtime_get_sync(gbphy_dev);
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if (ret)
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return ret;
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ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
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&request, sizeof(request), NULL, 0);
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gbphy_runtime_put_autosuspend(gbphy_dev);
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return ret;
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}
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static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
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u8 which)
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{
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struct gb_pwm_deactivate_request request;
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struct gbphy_device *gbphy_dev;
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int ret;
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if (which > pwmc->pwm_max)
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return -EINVAL;
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request.which = which;
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gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
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ret = gbphy_runtime_get_sync(gbphy_dev);
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if (ret)
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return ret;
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ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
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&request, sizeof(request), NULL, 0);
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gbphy_runtime_put_autosuspend(gbphy_dev);
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return ret;
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}
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static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
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u8 which, u32 duty, u32 period)
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{
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struct gb_pwm_config_request request;
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struct gbphy_device *gbphy_dev;
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int ret;
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if (which > pwmc->pwm_max)
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return -EINVAL;
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request.which = which;
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request.duty = cpu_to_le32(duty);
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request.period = cpu_to_le32(period);
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gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
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ret = gbphy_runtime_get_sync(gbphy_dev);
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if (ret)
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return ret;
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ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
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&request, sizeof(request), NULL, 0);
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gbphy_runtime_put_autosuspend(gbphy_dev);
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return ret;
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}
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static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
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u8 which, u8 polarity)
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{
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struct gb_pwm_polarity_request request;
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struct gbphy_device *gbphy_dev;
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int ret;
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if (which > pwmc->pwm_max)
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return -EINVAL;
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request.which = which;
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request.polarity = polarity;
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gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
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ret = gbphy_runtime_get_sync(gbphy_dev);
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if (ret)
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return ret;
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ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
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&request, sizeof(request), NULL, 0);
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gbphy_runtime_put_autosuspend(gbphy_dev);
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return ret;
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}
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static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
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u8 which)
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{
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struct gb_pwm_enable_request request;
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struct gbphy_device *gbphy_dev;
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int ret;
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if (which > pwmc->pwm_max)
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return -EINVAL;
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request.which = which;
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gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
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ret = gbphy_runtime_get_sync(gbphy_dev);
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if (ret)
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return ret;
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ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
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&request, sizeof(request), NULL, 0);
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if (ret)
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gbphy_runtime_put_autosuspend(gbphy_dev);
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return ret;
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}
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static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
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u8 which)
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{
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struct gb_pwm_disable_request request;
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struct gbphy_device *gbphy_dev;
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int ret;
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if (which > pwmc->pwm_max)
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return -EINVAL;
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request.which = which;
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ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
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&request, sizeof(request), NULL, 0);
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gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
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gbphy_runtime_put_autosuspend(gbphy_dev);
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return ret;
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}
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static int gb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
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return gb_pwm_activate_operation(pwmc, pwm->hwpwm);
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};
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static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
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if (pwm_is_enabled(pwm))
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dev_warn(chip->dev, "freeing PWM device without disabling\n");
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gb_pwm_deactivate_operation(pwmc, pwm->hwpwm);
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}
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static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
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const struct pwm_state *state)
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{
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int err;
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bool enabled = pwm->state.enabled;
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u64 period = state->period;
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u64 duty_cycle = state->duty_cycle;
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struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
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/* Set polarity */
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if (state->polarity != pwm->state.polarity) {
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if (enabled) {
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gb_pwm_disable_operation(pwmc, pwm->hwpwm);
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enabled = false;
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}
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err = gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, state->polarity);
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if (err)
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return err;
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}
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if (!state->enabled) {
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if (enabled)
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gb_pwm_disable_operation(pwmc, pwm->hwpwm);
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return 0;
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}
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/*
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* Set period and duty cycle
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*
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* PWM privodes 64-bit period and duty_cycle, but greybus only accepts
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* 32-bit, so their values have to be limited to U32_MAX.
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*/
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if (period > U32_MAX)
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period = U32_MAX;
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if (duty_cycle > period)
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duty_cycle = period;
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err = gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_cycle, period);
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if (err)
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return err;
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/* enable/disable */
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if (!enabled)
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return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
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return 0;
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}
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static const struct pwm_ops gb_pwm_ops = {
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.request = gb_pwm_request,
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.free = gb_pwm_free,
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.apply = gb_pwm_apply,
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.owner = THIS_MODULE,
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};
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static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
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const struct gbphy_device_id *id)
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{
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struct gb_connection *connection;
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struct gb_pwm_chip *pwmc;
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struct pwm_chip *pwm;
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int ret;
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pwmc = kzalloc(sizeof(*pwmc), GFP_KERNEL);
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if (!pwmc)
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return -ENOMEM;
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connection = gb_connection_create(gbphy_dev->bundle,
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le16_to_cpu(gbphy_dev->cport_desc->id),
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NULL);
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if (IS_ERR(connection)) {
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ret = PTR_ERR(connection);
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goto exit_pwmc_free;
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}
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pwmc->connection = connection;
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gb_connection_set_data(connection, pwmc);
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gb_gbphy_set_data(gbphy_dev, pwmc);
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ret = gb_connection_enable(connection);
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if (ret)
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goto exit_connection_destroy;
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/* Query number of pwms present */
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ret = gb_pwm_count_operation(pwmc);
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if (ret)
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goto exit_connection_disable;
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pwm = &pwmc->chip;
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pwm->dev = &gbphy_dev->dev;
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pwm->ops = &gb_pwm_ops;
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pwm->npwm = pwmc->pwm_max + 1;
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ret = pwmchip_add(pwm);
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if (ret) {
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dev_err(&gbphy_dev->dev,
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"failed to register PWM: %d\n", ret);
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goto exit_connection_disable;
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}
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gbphy_runtime_put_autosuspend(gbphy_dev);
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return 0;
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exit_connection_disable:
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gb_connection_disable(connection);
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exit_connection_destroy:
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gb_connection_destroy(connection);
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exit_pwmc_free:
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kfree(pwmc);
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return ret;
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}
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static void gb_pwm_remove(struct gbphy_device *gbphy_dev)
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{
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struct gb_pwm_chip *pwmc = gb_gbphy_get_data(gbphy_dev);
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struct gb_connection *connection = pwmc->connection;
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int ret;
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ret = gbphy_runtime_get_sync(gbphy_dev);
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if (ret)
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gbphy_runtime_get_noresume(gbphy_dev);
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pwmchip_remove(&pwmc->chip);
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gb_connection_disable(connection);
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gb_connection_destroy(connection);
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kfree(pwmc);
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}
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static const struct gbphy_device_id gb_pwm_id_table[] = {
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{ GBPHY_PROTOCOL(GREYBUS_PROTOCOL_PWM) },
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{ },
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};
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MODULE_DEVICE_TABLE(gbphy, gb_pwm_id_table);
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static struct gbphy_driver pwm_driver = {
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.name = "pwm",
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.probe = gb_pwm_probe,
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.remove = gb_pwm_remove,
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.id_table = gb_pwm_id_table,
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};
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module_gbphy_driver(pwm_driver);
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MODULE_LICENSE("GPL v2");
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