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authorJiri Kosina <jkosina@suse.cz>2021-09-01 23:01:27 +0300
committerJiri Kosina <jkosina@suse.cz>2021-09-01 23:01:27 +0300
commit6ef9233f4a42c290ef745a8a5242673707894856 (patch)
tree7709d768fe61486c22ed7b9c049b7f8f729cc3b7 /drivers/hid/i2c-hid
parentdab6e4f452c2fd45c15c701e6f7be665a72c7add (diff)
parent25ddd7cfc582d6001c3b9e18e96c9b3a58523d66 (diff)
downloadlinux-6ef9233f4a42c290ef745a8a5242673707894856.tar.xz
Merge branch 'for-5.15/goodix' into for-linus
- power management improvement for Goodix driver
Diffstat (limited to 'drivers/hid/i2c-hid')
-rw-r--r--drivers/hid/i2c-hid/i2c-hid-of-goodix.c92
1 files changed, 79 insertions, 13 deletions
diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
index ee0225982a82..52674149a275 100644
--- a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
+++ b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
@@ -26,28 +26,29 @@ struct i2c_hid_of_goodix {
struct i2chid_ops ops;
struct regulator *vdd;
+ struct notifier_block nb;
+ struct mutex regulator_mutex;
struct gpio_desc *reset_gpio;
const struct goodix_i2c_hid_timing_data *timings;
};
-static int goodix_i2c_hid_power_up(struct i2chid_ops *ops)
+static void goodix_i2c_hid_deassert_reset(struct i2c_hid_of_goodix *ihid_goodix,
+ bool regulator_just_turned_on)
{
- struct i2c_hid_of_goodix *ihid_goodix =
- container_of(ops, struct i2c_hid_of_goodix, ops);
- int ret;
-
- ret = regulator_enable(ihid_goodix->vdd);
- if (ret)
- return ret;
-
- if (ihid_goodix->timings->post_power_delay_ms)
+ if (regulator_just_turned_on && ihid_goodix->timings->post_power_delay_ms)
msleep(ihid_goodix->timings->post_power_delay_ms);
gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 0);
if (ihid_goodix->timings->post_gpio_reset_delay_ms)
msleep(ihid_goodix->timings->post_gpio_reset_delay_ms);
+}
- return 0;
+static int goodix_i2c_hid_power_up(struct i2chid_ops *ops)
+{
+ struct i2c_hid_of_goodix *ihid_goodix =
+ container_of(ops, struct i2c_hid_of_goodix, ops);
+
+ return regulator_enable(ihid_goodix->vdd);
}
static void goodix_i2c_hid_power_down(struct i2chid_ops *ops)
@@ -55,20 +56,54 @@ static void goodix_i2c_hid_power_down(struct i2chid_ops *ops)
struct i2c_hid_of_goodix *ihid_goodix =
container_of(ops, struct i2c_hid_of_goodix, ops);
- gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);
regulator_disable(ihid_goodix->vdd);
}
+static int ihid_goodix_vdd_notify(struct notifier_block *nb,
+ unsigned long event,
+ void *ignored)
+{
+ struct i2c_hid_of_goodix *ihid_goodix =
+ container_of(nb, struct i2c_hid_of_goodix, nb);
+ int ret = NOTIFY_OK;
+
+ mutex_lock(&ihid_goodix->regulator_mutex);
+
+ switch (event) {
+ case REGULATOR_EVENT_PRE_DISABLE:
+ gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);
+ break;
+
+ case REGULATOR_EVENT_ENABLE:
+ goodix_i2c_hid_deassert_reset(ihid_goodix, true);
+ break;
+
+ case REGULATOR_EVENT_ABORT_DISABLE:
+ goodix_i2c_hid_deassert_reset(ihid_goodix, false);
+ break;
+
+ default:
+ ret = NOTIFY_DONE;
+ break;
+ }
+
+ mutex_unlock(&ihid_goodix->regulator_mutex);
+
+ return ret;
+}
+
static int i2c_hid_of_goodix_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_hid_of_goodix *ihid_goodix;
-
+ int ret;
ihid_goodix = devm_kzalloc(&client->dev, sizeof(*ihid_goodix),
GFP_KERNEL);
if (!ihid_goodix)
return -ENOMEM;
+ mutex_init(&ihid_goodix->regulator_mutex);
+
ihid_goodix->ops.power_up = goodix_i2c_hid_power_up;
ihid_goodix->ops.power_down = goodix_i2c_hid_power_down;
@@ -84,6 +119,37 @@ static int i2c_hid_of_goodix_probe(struct i2c_client *client,
ihid_goodix->timings = device_get_match_data(&client->dev);
+ /*
+ * We need to control the "reset" line in lockstep with the regulator
+ * actually turning on an off instead of just when we make the request.
+ * This matters if the regulator is shared with another consumer.
+ * - If the regulator is off then we must assert reset. The reset
+ * line is active low and on some boards it could cause a current
+ * leak if left high.
+ * - If the regulator is on then we don't want reset asserted for very
+ * long. Holding the controller in reset apparently draws extra
+ * power.
+ */
+ mutex_lock(&ihid_goodix->regulator_mutex);
+ ihid_goodix->nb.notifier_call = ihid_goodix_vdd_notify;
+ ret = devm_regulator_register_notifier(ihid_goodix->vdd, &ihid_goodix->nb);
+ if (ret) {
+ mutex_unlock(&ihid_goodix->regulator_mutex);
+ return dev_err_probe(&client->dev, ret,
+ "regulator notifier request failed\n");
+ }
+
+ /*
+ * If someone else is holding the regulator on (or the regulator is
+ * an always-on one) we might never be told to deassert reset. Do it
+ * now. Here we'll assume that someone else might have _just
+ * barely_ turned the regulator on so we'll do the full
+ * "post_power_delay" just in case.
+ */
+ if (ihid_goodix->reset_gpio && regulator_is_enabled(ihid_goodix->vdd))
+ goodix_i2c_hid_deassert_reset(ihid_goodix, true);
+ mutex_unlock(&ihid_goodix->regulator_mutex);
+
return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001);
}