| /* |
| * PWM Greybus driver. |
| * |
| * Copyright 2014 Google Inc. |
| * Copyright 2014 Linaro Ltd. |
| * |
| * Released under the GPLv2 only. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/pwm.h> |
| #include "greybus.h" |
| |
| struct gb_pwm_chip { |
| struct gb_connection *connection; |
| u8 version_major; |
| u8 version_minor; |
| u8 pwm_max; /* max pwm number */ |
| |
| struct pwm_chip chip; |
| struct pwm_chip *pwm; |
| }; |
| #define pwm_chip_to_gb_pwm_chip(chip) \ |
| container_of(chip, struct gb_pwm_chip, chip) |
| |
| /* Version of the Greybus PWM protocol we support */ |
| #define GB_PWM_VERSION_MAJOR 0x00 |
| #define GB_PWM_VERSION_MINOR 0x01 |
| |
| /* Greybus PWM request types */ |
| #define GB_PWM_TYPE_INVALID 0x00 |
| #define GB_PWM_TYPE_PROTOCOL_VERSION 0x01 |
| #define GB_PWM_TYPE_PWM_COUNT 0x02 |
| #define GB_PWM_TYPE_ACTIVATE 0x03 |
| #define GB_PWM_TYPE_DEACTIVATE 0x04 |
| #define GB_PWM_TYPE_CONFIG 0x05 |
| #define GB_PWM_TYPE_POLARITY 0x06 |
| #define GB_PWM_TYPE_ENABLE 0x07 |
| #define GB_PWM_TYPE_DISABLE 0x08 |
| #define GB_PWM_TYPE_RESPONSE 0x80 /* OR'd with rest */ |
| |
| struct gb_pwm_simple_response { |
| __u8 status; |
| }; |
| |
| /* version request has no payload */ |
| struct gb_pwm_proto_version_response { |
| __u8 status; |
| __u8 major; |
| __u8 minor; |
| }; |
| |
| /* pwm count request has no payload */ |
| struct gb_pwm_count_response { |
| __u8 status; |
| __u8 count; |
| }; |
| |
| struct gb_pwm_activate_request { |
| __u8 which; |
| }; |
| |
| struct gb_pwm_deactivate_request { |
| __u8 which; |
| }; |
| |
| struct gb_pwm_config_request { |
| __u8 which; |
| __u32 duty; |
| __u32 period; |
| }; |
| |
| struct gb_pwm_polarity_request { |
| __u8 which; |
| __u8 polarity; |
| }; |
| |
| struct gb_pwm_enable_request { |
| __u8 which; |
| }; |
| |
| struct gb_pwm_disable_request { |
| __u8 which; |
| }; |
| |
| /* |
| * This request only uses the connection field, and if successful, |
| * fills in the major and minor protocol version of the target. |
| */ |
| static int gb_pwm_proto_version_operation(struct gb_pwm_chip *pwmc) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_proto_version_response *response; |
| int ret; |
| |
| /* protocol version request has no payload */ |
| operation = gb_operation_create(connection, |
| GB_PWM_TYPE_PROTOCOL_VERSION, |
| 0, sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("version operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "version response %hhu", |
| response->status); |
| ret = -EIO; |
| } else { |
| if (response->major > GB_PWM_VERSION_MAJOR) { |
| pr_err("unsupported major version (%hhu > %hhu)\n", |
| response->major, GB_PWM_VERSION_MAJOR); |
| ret = -ENOTSUPP; |
| goto out; |
| } |
| pwmc->version_major = response->major; |
| pwmc->version_minor = response->minor; |
| } |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_count_response *response; |
| int ret; |
| |
| /* pwm count request has no payload */ |
| operation = gb_operation_create(connection, GB_PWM_TYPE_PWM_COUNT, |
| 0, sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("line count operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "pwm count response %hhu", |
| response->status); |
| ret = -EIO; |
| } else |
| pwmc->pwm_max = response->count; |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc, |
| u8 which) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_activate_request *request; |
| struct gb_pwm_simple_response *response; |
| int ret; |
| |
| if (which > pwmc->pwm_max) |
| return -EINVAL; |
| |
| /* activate response has no payload */ |
| operation = gb_operation_create(connection, GB_PWM_TYPE_ACTIVATE, |
| sizeof(*request), sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| request = operation->request.payload; |
| request->which = which; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("activate operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "activate response %hhu", |
| response->status); |
| ret = -EIO; |
| } |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc, |
| u8 which) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_deactivate_request *request; |
| struct gb_pwm_simple_response *response; |
| int ret; |
| |
| if (which > pwmc->pwm_max) |
| return -EINVAL; |
| |
| /* deactivate response has no payload */ |
| operation = gb_operation_create(connection, GB_PWM_TYPE_DEACTIVATE, |
| sizeof(*request), sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| request = operation->request.payload; |
| request->which = which; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("deactivate operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "deactivate response %hhu", |
| response->status); |
| ret = -EIO; |
| } |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc, |
| u8 which, u32 duty, u32 period) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_config_request *request; |
| struct gb_pwm_simple_response *response; |
| int ret; |
| |
| if (which > pwmc->pwm_max) |
| return -EINVAL; |
| |
| operation = gb_operation_create(connection, GB_PWM_TYPE_CONFIG, |
| sizeof(*request), sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| request = operation->request.payload; |
| request->which = which; |
| request->duty = duty; |
| request->period = period; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("config operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "config response %hhu", |
| response->status); |
| ret = -EIO; |
| } |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| |
| static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc, |
| u8 which, u8 polarity) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_polarity_request *request; |
| struct gb_pwm_simple_response *response; |
| int ret; |
| |
| if (which > pwmc->pwm_max) |
| return -EINVAL; |
| |
| operation = gb_operation_create(connection, GB_PWM_TYPE_POLARITY, |
| sizeof(*request), sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| request = operation->request.payload; |
| request->which = which; |
| request->polarity = polarity; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("set polarity operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "set polarity response %hhu", |
| response->status); |
| ret = -EIO; |
| } |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc, |
| u8 which) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_enable_request *request; |
| struct gb_pwm_simple_response *response; |
| int ret; |
| |
| if (which > pwmc->pwm_max) |
| return -EINVAL; |
| |
| /* enable response has no payload */ |
| operation = gb_operation_create(connection, GB_PWM_TYPE_ENABLE, |
| sizeof(*request), sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| request = operation->request.payload; |
| request->which = which; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("enable operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "enable response %hhu", |
| response->status); |
| ret = -EIO; |
| } |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc, |
| u8 which) |
| { |
| struct gb_connection *connection = pwmc->connection; |
| struct gb_operation *operation; |
| struct gb_pwm_disable_request *request; |
| struct gb_pwm_simple_response *response; |
| int ret; |
| |
| if (which > pwmc->pwm_max) |
| return -EINVAL; |
| |
| /* disable response has no payload */ |
| operation = gb_operation_create(connection, GB_PWM_TYPE_DISABLE, |
| sizeof(*request), sizeof(*response)); |
| if (!operation) |
| return -ENOMEM; |
| request = operation->request.payload; |
| request->which = which; |
| |
| /* Synchronous operation--no callback */ |
| ret = gb_operation_request_send(operation, NULL); |
| if (ret) { |
| pr_err("disable operation failed (%d)\n", ret); |
| goto out; |
| } |
| |
| response = operation->response.payload; |
| if (response->status) { |
| gb_connection_err(connection, "disable response %hhu", |
| response->status); |
| ret = -EIO; |
| } |
| out: |
| gb_operation_destroy(operation); |
| |
| return ret; |
| } |
| |
| static int gb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) |
| { |
| struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); |
| |
| return gb_pwm_activate_operation(pwmc, pwm->hwpwm); |
| }; |
| |
| static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) |
| { |
| struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); |
| |
| if (test_bit(PWMF_ENABLED, &pwm->flags)) |
| dev_warn(chip->dev, "freeing PWM device without disabling\n"); |
| |
| gb_pwm_deactivate_operation(pwmc, pwm->hwpwm); |
| } |
| |
| static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, |
| int duty_ns, int period_ns) |
| { |
| struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); |
| |
| return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns); |
| }; |
| |
| static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, |
| enum pwm_polarity polarity) |
| { |
| struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); |
| |
| return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity); |
| }; |
| |
| static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
| { |
| struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); |
| |
| return gb_pwm_enable_operation(pwmc, pwm->hwpwm); |
| }; |
| |
| static void gb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) |
| { |
| struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip); |
| |
| gb_pwm_disable_operation(pwmc, pwm->hwpwm); |
| }; |
| |
| static const struct pwm_ops gb_pwm_ops = { |
| .request = gb_pwm_request, |
| .free = gb_pwm_free, |
| .config = gb_pwm_config, |
| .set_polarity = gb_pwm_set_polarity, |
| .enable = gb_pwm_enable, |
| .disable = gb_pwm_disable, |
| .owner = THIS_MODULE, |
| }; |
| |
| static int gb_pwm_connection_init(struct gb_connection *connection) |
| { |
| struct gb_pwm_chip *pwmc; |
| struct pwm_chip *pwm; |
| int ret; |
| |
| pwmc = kzalloc(sizeof(*pwmc), GFP_KERNEL); |
| if (!pwmc) |
| return -ENOMEM; |
| pwmc->connection = connection; |
| |
| /* Check for compatible protocol version */ |
| ret = gb_pwm_proto_version_operation(pwmc); |
| if (ret) |
| goto out_err; |
| |
| /* Query number of pwms present */ |
| ret = gb_pwm_count_operation(pwmc); |
| if (ret) |
| goto out_err; |
| |
| pwm = &pwmc->chip; |
| |
| pwm->dev = &connection->dev; |
| pwm->ops = &gb_pwm_ops; |
| pwm->base = -1; /* Allocate base dynamically */ |
| pwm->npwm = pwmc->pwm_max + 1; |
| pwm->can_sleep = true; /* FIXME */ |
| |
| ret = pwmchip_add(pwm); |
| if (ret) { |
| pr_err("Failed to register PWM\n"); |
| return ret; |
| } |
| connection->private = pwmc; |
| |
| return 0; |
| out_err: |
| kfree(pwmc); |
| return ret; |
| } |
| |
| static void gb_pwm_connection_exit(struct gb_connection *connection) |
| { |
| struct gb_pwm_chip *pwmc = connection->private; |
| |
| if (!pwmc) |
| return; |
| |
| pwmchip_remove(&pwmc->chip); |
| /* kref_put(pwmc->connection) */ |
| kfree(pwmc); |
| } |
| |
| static struct gb_protocol pwm_protocol = { |
| .id = GREYBUS_PROTOCOL_PWM, |
| .major = 0, |
| .minor = 1, |
| .connection_init = gb_pwm_connection_init, |
| .connection_exit = gb_pwm_connection_exit, |
| .request_recv = NULL, /* no incoming requests */ |
| }; |
| |
| bool gb_pwm_protocol_init(void) |
| { |
| return gb_protocol_register(&pwm_protocol); |
| } |
| |
| void gb_pwm_protocol_exit(void) |
| { |
| gb_protocol_deregister(&pwm_protocol); |
| } |