2014-11-13 07:14:13 -07:00
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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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* Released under the GPLv2 only.
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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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2015-05-22 11:35:31 -06:00
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2014-11-13 07:14:13 -07:00
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#include "greybus.h"
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struct gb_pwm_chip {
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struct gb_connection *connection;
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u8 version_major;
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u8 version_minor;
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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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#define pwm_chip_to_gb_pwm_chip(chip) \
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container_of(chip, struct gb_pwm_chip, chip)
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2015-01-21 05:42:36 -07:00
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/* Define get_version() routine */
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define_get_version(gb_pwm_chip, PWM);
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2014-11-13 07:14:13 -07:00
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static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
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{
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2014-11-23 18:45:24 -07:00
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struct gb_pwm_count_response response;
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2014-11-13 07:14:13 -07:00
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int ret;
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2014-11-23 18:45:24 -07:00
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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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2014-11-13 07:14:13 -07:00
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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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2014-11-23 18:45:24 -07:00
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struct gb_pwm_activate_request request;
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2014-11-13 07:14:13 -07:00
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if (which > pwmc->pwm_max)
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return -EINVAL;
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2014-11-23 18:45:24 -07:00
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request.which = which;
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return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
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&request, sizeof(request), NULL, 0);
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2014-11-13 07:14:13 -07:00
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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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2014-11-23 18:45:24 -07:00
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struct gb_pwm_deactivate_request request;
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2014-11-13 07:14:13 -07:00
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if (which > pwmc->pwm_max)
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return -EINVAL;
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2014-11-23 18:45:24 -07:00
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request.which = which;
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return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
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&request, sizeof(request), NULL, 0);
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2014-11-13 07:14:13 -07:00
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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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2014-11-23 18:45:24 -07:00
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struct gb_pwm_config_request request;
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2014-11-13 07:14:13 -07:00
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if (which > pwmc->pwm_max)
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return -EINVAL;
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2014-11-23 18:45:24 -07:00
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request.which = which;
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2014-12-02 14:48:09 -07:00
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request.duty = cpu_to_le32(duty);
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request.period = cpu_to_le32(period);
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2014-11-23 18:45:24 -07:00
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return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
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&request, sizeof(request), NULL, 0);
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2014-11-13 07:14:13 -07:00
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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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2014-11-23 18:45:24 -07:00
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struct gb_pwm_polarity_request request;
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2014-11-13 07:14:13 -07:00
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if (which > pwmc->pwm_max)
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return -EINVAL;
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2014-11-23 18:45:24 -07:00
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request.which = which;
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request.polarity = polarity;
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return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
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&request, sizeof(request), NULL, 0);
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2014-11-13 07:14:13 -07:00
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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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2014-11-23 18:45:24 -07:00
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struct gb_pwm_enable_request request;
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2014-11-13 07:14:13 -07:00
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if (which > pwmc->pwm_max)
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return -EINVAL;
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2014-11-23 18:45:24 -07:00
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request.which = which;
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return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
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&request, sizeof(request), NULL, 0);
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2014-11-13 07:14:13 -07:00
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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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2014-11-23 18:45:24 -07:00
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struct gb_pwm_disable_request request;
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2014-11-13 07:14:13 -07:00
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if (which > pwmc->pwm_max)
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return -EINVAL;
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2014-11-23 18:45:24 -07:00
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request.which = which;
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return gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
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&request, sizeof(request), NULL, 0);
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2014-11-13 07:14:13 -07:00
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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 (test_bit(PWMF_ENABLED, &pwm->flags))
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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_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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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_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns);
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};
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static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
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enum pwm_polarity polarity)
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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_set_polarity_operation(pwmc, pwm->hwpwm, polarity);
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};
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static int gb_pwm_enable(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_enable_operation(pwmc, pwm->hwpwm);
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};
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static void gb_pwm_disable(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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gb_pwm_disable_operation(pwmc, pwm->hwpwm);
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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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.config = gb_pwm_config,
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.set_polarity = gb_pwm_set_polarity,
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.enable = gb_pwm_enable,
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.disable = gb_pwm_disable,
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.owner = THIS_MODULE,
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};
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static int gb_pwm_connection_init(struct gb_connection *connection)
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{
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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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pwmc->connection = connection;
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2014-12-03 11:27:42 -07:00
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connection->private = pwmc;
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2014-11-13 07:14:13 -07:00
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/* Check for compatible protocol version */
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2015-01-21 05:42:36 -07:00
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ret = get_version(pwmc);
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2014-11-13 07:14:13 -07:00
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if (ret)
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goto out_err;
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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 out_err;
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pwm = &pwmc->chip;
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pwm->dev = &connection->dev;
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pwm->ops = &gb_pwm_ops;
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pwm->base = -1; /* Allocate base dynamically */
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pwm->npwm = pwmc->pwm_max + 1;
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pwm->can_sleep = true; /* FIXME */
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ret = pwmchip_add(pwm);
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if (ret) {
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pr_err("Failed to register PWM\n");
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2015-03-17 03:55:50 -06:00
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goto out_err;
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2014-11-13 07:14:13 -07:00
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}
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return 0;
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out_err:
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kfree(pwmc);
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return ret;
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}
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static void gb_pwm_connection_exit(struct gb_connection *connection)
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{
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struct gb_pwm_chip *pwmc = connection->private;
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if (!pwmc)
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return;
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pwmchip_remove(&pwmc->chip);
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/* kref_put(pwmc->connection) */
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kfree(pwmc);
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}
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static struct gb_protocol pwm_protocol = {
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2014-12-24 14:01:45 -07:00
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.name = "pwm",
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2014-11-13 07:14:13 -07:00
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.id = GREYBUS_PROTOCOL_PWM,
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.major = 0,
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.minor = 1,
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.connection_init = gb_pwm_connection_init,
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.connection_exit = gb_pwm_connection_exit,
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.request_recv = NULL, /* no incoming requests */
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};
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2015-07-01 00:43:52 -06:00
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gb_builtin_protocol_driver(pwm_protocol);
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