[patch 25/32] greybus: bridged phy pwm driver

[Greg KH <gregkh@linuxfoundation.org>]

This driver implements the Greybus bridged phy pwm class protocol.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/greybus/pwm.c |  338 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 338 insertions(+)

--- /dev/null
+++ b/drivers/greybus/pwm.c
@@ -0,0 +1,338 @@
+/*
+ * 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"
+#include "gbphy.h"
+
+struct gb_pwm_chip {
+	struct gb_connection	*connection;
+	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)
+
+
+static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
+{
+	struct gb_pwm_count_response response;
+	int ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
+				NULL, 0, &response, sizeof(response));
+	if (ret)
+		return ret;
+	pwmc->pwm_max = response.count;
+	return 0;
+}
+
+static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
+				     u8 which)
+{
+	struct gb_pwm_activate_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
+
+	if (which > pwmc->pwm_max)
+		return -EINVAL;
+
+	request.which = which;
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
+}
+
+static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
+				       u8 which)
+{
+	struct gb_pwm_deactivate_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
+
+	if (which > pwmc->pwm_max)
+		return -EINVAL;
+
+	request.which = which;
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
+}
+
+static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
+				   u8 which, u32 duty, u32 period)
+{
+	struct gb_pwm_config_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
+
+	if (which > pwmc->pwm_max)
+		return -EINVAL;
+
+	request.which = which;
+	request.duty = cpu_to_le32(duty);
+	request.period = cpu_to_le32(period);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
+}
+
+static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
+					 u8 which, u8 polarity)
+{
+	struct gb_pwm_polarity_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
+
+	if (which > pwmc->pwm_max)
+		return -EINVAL;
+
+	request.which = which;
+	request.polarity = polarity;
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
+}
+
+static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
+				   u8 which)
+{
+	struct gb_pwm_enable_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
+
+	if (which > pwmc->pwm_max)
+		return -EINVAL;
+
+	request.which = which;
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		return ret;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
+				&request, sizeof(request), NULL, 0);
+	if (ret)
+		gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	return ret;
+}
+
+static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
+				    u8 which)
+{
+	struct gb_pwm_disable_request request;
+	struct gbphy_device *gbphy_dev;
+	int ret;
+
+	if (which > pwmc->pwm_max)
+		return -EINVAL;
+
+	request.which = which;
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
+				&request, sizeof(request), NULL, 0);
+
+	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+
+	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 (pwm_is_enabled(pwm))
+		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_probe(struct gbphy_device *gbphy_dev,
+			const struct gbphy_device_id *id)
+{
+	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;
+
+	connection = gb_connection_create(gbphy_dev->bundle,
+					  le16_to_cpu(gbphy_dev->cport_desc->id),
+					  NULL);
+	if (IS_ERR(connection)) {
+		ret = PTR_ERR(connection);
+		goto exit_pwmc_free;
+	}
+
+	pwmc->connection = connection;
+	gb_connection_set_data(connection, pwmc);
+	gb_gbphy_set_data(gbphy_dev, pwmc);
+
+	ret = gb_connection_enable(connection);
+	if (ret)
+		goto exit_connection_destroy;
+
+	/* Query number of pwms present */
+	ret = gb_pwm_count_operation(pwmc);
+	if (ret)
+		goto exit_connection_disable;
+
+	pwm = &pwmc->chip;
+
+	pwm->dev = &gbphy_dev->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) {
+		dev_err(&gbphy_dev->dev,
+			"failed to register PWM: %d\n", ret);
+		goto exit_connection_disable;
+	}
+
+	gbphy_runtime_put_autosuspend(gbphy_dev);
+	return 0;
+
+exit_connection_disable:
+	gb_connection_disable(connection);
+exit_connection_destroy:
+	gb_connection_destroy(connection);
+exit_pwmc_free:
+	kfree(pwmc);
+	return ret;
+}
+
+static void gb_pwm_remove(struct gbphy_device *gbphy_dev)
+{
+	struct gb_pwm_chip *pwmc = gb_gbphy_get_data(gbphy_dev);
+	struct gb_connection *connection = pwmc->connection;
+	int ret;
+
+	ret = gbphy_runtime_get_sync(gbphy_dev);
+	if (ret)
+		gbphy_runtime_get_noresume(gbphy_dev);
+
+	pwmchip_remove(&pwmc->chip);
+	gb_connection_disable(connection);
+	gb_connection_destroy(connection);
+	kfree(pwmc);
+}
+
+static const struct gbphy_device_id gb_pwm_id_table[] = {
+	{ GBPHY_PROTOCOL(GREYBUS_PROTOCOL_PWM) },
+	{ },
+};
+MODULE_DEVICE_TABLE(gbphy, gb_pwm_id_table);
+
+static struct gbphy_driver pwm_driver = {
+	.name		= "pwm",
+	.probe		= gb_pwm_probe,
+	.remove		= gb_pwm_remove,
+	.id_table	= gb_pwm_id_table,
+};
+
+module_gbphy_driver(pwm_driver);
+MODULE_LICENSE("GPL v2");