OpenCloudOS-Kernel/drivers/pwm/pwm-cros-ec.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Expose a PWM controlled by the ChromeOS EC to the host processor.
*
* Copyright (C) 2016 Google, Inc.
*/
#include <linux/module.h>
mfd / platform: cros_ec: Reorganize platform and mfd includes There is a bit of mess between cros-ec mfd includes and platform includes. For example, we have a linux/mfd/cros_ec.h include that exports the interface implemented in platform/chrome/cros_ec_proto.c. Or we have a linux/mfd/cros_ec_commands.h file that is non related to the multifunction device (in the sense that is not exporting any function of the mfd device). This causes crossed includes between mfd and platform/chrome subsystems and makes the code difficult to read, apart from creating 'curious' situations where a platform/chrome driver includes a linux/mfd/cros_ec.h file just to get the exported functions that are implemented in another platform/chrome driver. In order to have a better separation on what the cros-ec multifunction driver does and what the cros-ec core provides move and rework the affected includes doing: - Move cros_ec_commands.h to include/linux/platform_data/cros_ec_commands.h - Get rid of the parts that are implemented in the platform/chrome/cros_ec_proto.c driver from include/linux/mfd/cros_ec.h to a new file include/linux/platform_data/cros_ec_proto.h - Update all the drivers with the new includes, so - Drivers that only need to know about the protocol include - linux/platform_data/cros_ec_proto.h - linux/platform_data/cros_ec_commands.h - Drivers that need to know about the cros-ec mfd device also include - linux/mfd/cros_ec.h Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> Acked-by: Chanwoo Choi <cw00.choi@samsung.com> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Tested-by: Gwendal Grignou <gwendal@chromium.org> Series changes: 3 - Fix dereferencing pointer to incomplete type 'struct cros_ec_dev' (lkp) Signed-off-by: Lee Jones <lee.jones@linaro.org>
2019-09-02 17:53:05 +08:00
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/slab.h>
#include <dt-bindings/mfd/cros_ec.h>
/**
* struct cros_ec_pwm_device - Driver data for EC PWM
*
* @dev: Device node
* @ec: Pointer to EC device
* @chip: PWM controller chip
* @use_pwm_type: Use PWM types instead of generic channels
*/
struct cros_ec_pwm_device {
struct device *dev;
struct cros_ec_device *ec;
struct pwm_chip chip;
bool use_pwm_type;
};
/**
* struct cros_ec_pwm - per-PWM driver data
* @duty_cycle: cached duty cycle
*/
struct cros_ec_pwm {
u16 duty_cycle;
};
static inline struct cros_ec_pwm_device *pwm_to_cros_ec_pwm(struct pwm_chip *c)
{
return container_of(c, struct cros_ec_pwm_device, chip);
}
static int cros_ec_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct cros_ec_pwm *channel;
channel = kzalloc(sizeof(*channel), GFP_KERNEL);
if (!channel)
return -ENOMEM;
pwm_set_chip_data(pwm, channel);
return 0;
}
static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
kfree(channel);
}
static int cros_ec_dt_type_to_pwm_type(u8 dt_index, u8 *pwm_type)
{
switch (dt_index) {
case CROS_EC_PWM_DT_KB_LIGHT:
*pwm_type = EC_PWM_TYPE_KB_LIGHT;
return 0;
case CROS_EC_PWM_DT_DISPLAY_LIGHT:
*pwm_type = EC_PWM_TYPE_DISPLAY_LIGHT;
return 0;
default:
return -EINVAL;
}
}
static int cros_ec_pwm_set_duty(struct cros_ec_pwm_device *ec_pwm, u8 index,
u16 duty)
{
struct cros_ec_device *ec = ec_pwm->ec;
struct {
struct cros_ec_command msg;
struct ec_params_pwm_set_duty params;
} __packed buf;
struct ec_params_pwm_set_duty *params = &buf.params;
struct cros_ec_command *msg = &buf.msg;
int ret;
memset(&buf, 0, sizeof(buf));
msg->version = 0;
msg->command = EC_CMD_PWM_SET_DUTY;
msg->insize = 0;
msg->outsize = sizeof(*params);
params->duty = duty;
if (ec_pwm->use_pwm_type) {
ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);
if (ret) {
dev_err(ec->dev, "Invalid PWM type index: %d\n", index);
return ret;
}
params->index = 0;
} else {
params->pwm_type = EC_PWM_TYPE_GENERIC;
params->index = index;
}
return cros_ec_cmd_xfer_status(ec, msg);
}
static int cros_ec_pwm_get_duty(struct cros_ec_pwm_device *ec_pwm, u8 index)
{
struct cros_ec_device *ec = ec_pwm->ec;
struct {
struct cros_ec_command msg;
union {
struct ec_params_pwm_get_duty params;
struct ec_response_pwm_get_duty resp;
};
} __packed buf;
struct ec_params_pwm_get_duty *params = &buf.params;
struct ec_response_pwm_get_duty *resp = &buf.resp;
struct cros_ec_command *msg = &buf.msg;
int ret;
memset(&buf, 0, sizeof(buf));
msg->version = 0;
msg->command = EC_CMD_PWM_GET_DUTY;
msg->insize = sizeof(*resp);
msg->outsize = sizeof(*params);
if (ec_pwm->use_pwm_type) {
ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);
if (ret) {
dev_err(ec->dev, "Invalid PWM type index: %d\n", index);
return ret;
}
params->index = 0;
} else {
params->pwm_type = EC_PWM_TYPE_GENERIC;
params->index = index;
}
ret = cros_ec_cmd_xfer_status(ec, msg);
if (ret < 0)
return ret;
return resp->duty;
}
static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state)
{
struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip);
struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
u16 duty_cycle;
int ret;
/* The EC won't let us change the period */
if (state->period != EC_PWM_MAX_DUTY)
return -EINVAL;
if (state->polarity != PWM_POLARITY_NORMAL)
return -EINVAL;
/*
* EC doesn't separate the concept of duty cycle and enabled, but
* kernel does. Translate.
*/
duty_cycle = state->enabled ? state->duty_cycle : 0;
ret = cros_ec_pwm_set_duty(ec_pwm, pwm->hwpwm, duty_cycle);
if (ret < 0)
return ret;
channel->duty_cycle = state->duty_cycle;
return 0;
}
pwm: Make .get_state() callback return an error code .get_state() might fail in some cases. To make it possible that a driver signals such a failure change the prototype of .get_state() to return an error code. This patch was created using coccinelle and the following semantic patch: @p1@ identifier getstatefunc; identifier driver; @@ struct pwm_ops driver = { ..., .get_state = getstatefunc ,... }; @p2@ identifier p1.getstatefunc; identifier chip, pwm, state; @@ -void +int getstatefunc(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { ... - return; + return 0; ... } plus the actual change of the prototype in include/linux/pwm.h (plus some manual fixing of indentions and empty lines). So for now all drivers return success unconditionally. They are adapted in the following patches to make the changes easier reviewable. Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Acked-by: Douglas Anderson <dianders@chromium.org> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-12-03 02:35:26 +08:00
static int cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
struct pwm_state *state)
{
struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip);
struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
int ret;
ret = cros_ec_pwm_get_duty(ec_pwm, pwm->hwpwm);
if (ret < 0) {
dev_err(chip->dev, "error getting initial duty: %d\n", ret);
return ret;
}
state->enabled = (ret > 0);
state->period = EC_PWM_MAX_DUTY;
/*
* Note that "disabled" and "duty cycle == 0" are treated the same. If
* the cached duty cycle is not zero, used the cached duty cycle. This
* ensures that the configured duty cycle is kept across a disable and
* enable operation and avoids potentially confusing consumers.
*
* For the case of the initial hardware readout, channel->duty_cycle
* will be 0 and the actual duty cycle read from the EC is used.
*/
if (ret == 0 && channel->duty_cycle > 0)
state->duty_cycle = channel->duty_cycle;
else
state->duty_cycle = ret;
pwm: Make .get_state() callback return an error code .get_state() might fail in some cases. To make it possible that a driver signals such a failure change the prototype of .get_state() to return an error code. This patch was created using coccinelle and the following semantic patch: @p1@ identifier getstatefunc; identifier driver; @@ struct pwm_ops driver = { ..., .get_state = getstatefunc ,... }; @p2@ identifier p1.getstatefunc; identifier chip, pwm, state; @@ -void +int getstatefunc(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { ... - return; + return 0; ... } plus the actual change of the prototype in include/linux/pwm.h (plus some manual fixing of indentions and empty lines). So for now all drivers return success unconditionally. They are adapted in the following patches to make the changes easier reviewable. Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Acked-by: Douglas Anderson <dianders@chromium.org> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-12-03 02:35:26 +08:00
return 0;
}
static struct pwm_device *
cros_ec_pwm_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
{
struct pwm_device *pwm;
if (args->args[0] >= pc->npwm)
return ERR_PTR(-EINVAL);
pwm = pwm_request_from_chip(pc, args->args[0], NULL);
if (IS_ERR(pwm))
return pwm;
/* The EC won't let us change the period */
pwm->args.period = EC_PWM_MAX_DUTY;
return pwm;
}
static const struct pwm_ops cros_ec_pwm_ops = {
.request = cros_ec_pwm_request,
.free = cros_ec_pwm_free,
.get_state = cros_ec_pwm_get_state,
.apply = cros_ec_pwm_apply,
.owner = THIS_MODULE,
};
/*
* Determine the number of supported PWMs. The EC does not return the number
* of PWMs it supports directly, so we have to read the pwm duty cycle for
* subsequent channels until we get an error.
*/
static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
{
int i, ret;
/* The index field is only 8 bits */
for (i = 0; i <= U8_MAX; i++) {
ret = cros_ec_pwm_get_duty(ec_pwm, i);
/*
* We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM
* responses; everything else is treated as an error.
* The EC error codes map to -EOPNOTSUPP and -EINVAL,
* so check for those.
*/
switch (ret) {
case -EOPNOTSUPP: /* invalid command */
return -ENODEV;
case -EINVAL: /* invalid parameter */
return i;
default:
if (ret < 0)
return ret;
break;
}
}
return U8_MAX;
}
static int cros_ec_pwm_probe(struct platform_device *pdev)
{
struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
struct cros_ec_pwm_device *ec_pwm;
struct pwm_chip *chip;
int ret;
if (!ec) {
dev_err(dev, "no parent EC device\n");
return -EINVAL;
}
ec_pwm = devm_kzalloc(dev, sizeof(*ec_pwm), GFP_KERNEL);
if (!ec_pwm)
return -ENOMEM;
chip = &ec_pwm->chip;
ec_pwm->ec = ec;
if (of_device_is_compatible(np, "google,cros-ec-pwm-type"))
ec_pwm->use_pwm_type = true;
/* PWM chip */
chip->dev = dev;
chip->ops = &cros_ec_pwm_ops;
chip->of_xlate = cros_ec_pwm_xlate;
chip->of_pwm_n_cells = 1;
if (ec_pwm->use_pwm_type) {
chip->npwm = CROS_EC_PWM_DT_COUNT;
} else {
ret = cros_ec_num_pwms(ec_pwm);
if (ret < 0) {
dev_err(dev, "Couldn't find PWMs: %d\n", ret);
return ret;
}
chip->npwm = ret;
}
dev_dbg(dev, "Probed %u PWMs\n", chip->npwm);
ret = pwmchip_add(chip);
if (ret < 0) {
dev_err(dev, "cannot register PWM: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, ec_pwm);
return ret;
}
static int cros_ec_pwm_remove(struct platform_device *dev)
{
struct cros_ec_pwm_device *ec_pwm = platform_get_drvdata(dev);
struct pwm_chip *chip = &ec_pwm->chip;
pwmchip_remove(chip);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id cros_ec_pwm_of_match[] = {
{ .compatible = "google,cros-ec-pwm" },
{ .compatible = "google,cros-ec-pwm-type" },
{},
};
MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
#endif
static struct platform_driver cros_ec_pwm_driver = {
.probe = cros_ec_pwm_probe,
.remove = cros_ec_pwm_remove,
.driver = {
.name = "cros-ec-pwm",
.of_match_table = of_match_ptr(cros_ec_pwm_of_match),
},
};
module_platform_driver(cros_ec_pwm_driver);
MODULE_ALIAS("platform:cros-ec-pwm");
MODULE_DESCRIPTION("ChromeOS EC PWM driver");
MODULE_LICENSE("GPL v2");