From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/drivers/pwm/pwm-cros-ec.c | 102 +++++++++++++++++++++++++++++++++++++-------------
1 files changed, 75 insertions(+), 27 deletions(-)
diff --git a/kernel/drivers/pwm/pwm-cros-ec.c b/kernel/drivers/pwm/pwm-cros-ec.c
index 98f6ac6..d4f4a13 100644
--- a/kernel/drivers/pwm/pwm-cros-ec.c
+++ b/kernel/drivers/pwm/pwm-cros-ec.c
@@ -6,8 +6,8 @@
*/
#include <linux/module.h>
-#include <linux/mfd/cros_ec.h>
-#include <linux/mfd/cros_ec_commands.h>
+#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>
@@ -25,9 +25,37 @@
struct pwm_chip chip;
};
+/**
+ * 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_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty)
@@ -53,8 +81,7 @@
return cros_ec_cmd_xfer_status(ec, msg);
}
-static int __cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index,
- u32 *result)
+static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
{
struct {
struct cros_ec_command msg;
@@ -79,24 +106,19 @@
params->index = index;
ret = cros_ec_cmd_xfer_status(ec, msg);
- if (result)
- *result = msg->result;
if (ret < 0)
return ret;
return resp->duty;
}
-static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
-{
- return __cros_ec_pwm_get_duty(ec, index, NULL);
-}
-
static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
- struct pwm_state *state)
+ const struct pwm_state *state)
{
struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip);
- int duty_cycle;
+ 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)
@@ -108,13 +130,20 @@
*/
duty_cycle = state->enabled ? state->duty_cycle : 0;
- return cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);
+ ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);
+ if (ret < 0)
+ return ret;
+
+ channel->duty_cycle = state->duty_cycle;
+
+ return 0;
}
static void 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->ec, pwm->hwpwm);
@@ -125,9 +154,21 @@
state->enabled = (ret > 0);
state->period = EC_PWM_MAX_DUTY;
+ state->polarity = PWM_POLARITY_NORMAL;
- /* Note that "disabled" and "duty cycle == 0" are treated the same */
- state->duty_cycle = ret;
+ /*
+ * 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;
}
static struct pwm_device *
@@ -149,34 +190,41 @@
}
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_device *ec)
{
int i, ret;
/* The index field is only 8 bits */
for (i = 0; i <= U8_MAX; i++) {
- u32 result = 0;
-
- ret = __cros_ec_pwm_get_duty(ec, i, &result);
- /* We want to parse EC protocol errors */
- if (ret < 0 && !(ret == -EPROTO && result))
- return ret;
-
+ ret = cros_ec_pwm_get_duty(ec, 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.
*/
- if (result == EC_RES_INVALID_COMMAND)
+ switch (ret) {
+ case -EOPNOTSUPP: /* invalid command */
return -ENODEV;
- else if (result == EC_RES_INVALID_PARAM)
+ case -EINVAL: /* invalid parameter */
return i;
- else if (result)
- return -EPROTO;
+ default:
+ if (ret < 0)
+ return ret;
+ break;
+ }
}
return U8_MAX;
--
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