[PATCH v3 08/11] platform/x86: int3472/discrete: Create a LED class device for the privacy LED

Hans de Goede
2022-12-16T11:32:25Z

On some systems, e.g. the Lenovo ThinkPad X1 Yoga gen 7 and the ThinkPad
X1 Nano gen 2 there is no clock-enable pin, triggering the:
"No clk GPIO. The privacy LED won't work" warning and causing the privacy
LED to not work.

Fix this by modeling the privacy LED as a LED class device rather then
integrating it with the registered clock.

Note this relies on media subsys changes to actually turn the LED on/off
when the sensor's v4l2_subdev's s_stream() operand gets called.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/platform/x86/intel/int3472/Makefile | 2 +-
.../x86/intel/int3472/clk_and_regulator.c | 3 -
drivers/platform/x86/intel/int3472/common.h | 15 +++-
drivers/platform/x86/intel/int3472/discrete.c | 52 ++++--------
drivers/platform/x86/intel/int3472/led.c | 79 +++++++++++++++++++
5 files changed, 108 insertions(+), 43 deletions(-)
create mode 100644 drivers/platform/x86/intel/int3472/led.c

diff --git a/drivers/platform/x86/intel/int3472/Makefile b/drivers/platform/x86/intel/int3472/Makefile
index cfec7784c5c9..9f16cb514397 100644
--- a/drivers/platform/x86/intel/int3472/Makefile
+++ b/drivers/platform/x86/intel/int3472/Makefile
@@ -1,4 +1,4 @@
obj-$(CONFIG_INTEL_SKL_INT3472) += intel_skl_int3472_discrete.o \
intel_skl_int3472_tps68470.o
-intel_skl_int3472_discrete-y := discrete.o clk_and_regulator.o common.o
+intel_skl_int3472_discrete-y := discrete.o clk_and_regulator.o led.o common.o
intel_skl_int3472_tps68470-y := tps68470.o tps68470_board_data.o common.o
diff --git a/drivers/platform/x86/intel/int3472/clk_and_regulator.c b/drivers/platform/x86/intel/int3472/clk_and_regulator.c
index 1cf958983e86..e61119b17677 100644
--- a/drivers/platform/x86/intel/int3472/clk_and_regulator.c
+++ b/drivers/platform/x86/intel/int3472/clk_and_regulator.c
@@ -23,8 +23,6 @@ static int skl_int3472_clk_prepare(struct clk_hw *hw)
struct int3472_gpio_clock *clk = to_int3472_clk(hw);

gpiod_set_value_cansleep(clk->ena_gpio, 1);
- gpiod_set_value_cansleep(clk->led_gpio, 1);
-
return 0;
}

@@ -33,7 +31,6 @@ static void skl_int3472_clk_unprepare(struct clk_hw *hw)
struct int3472_gpio_clock *clk = to_int3472_clk(hw);

gpiod_set_value_cansleep(clk->ena_gpio, 0);
- gpiod_set_value_cansleep(clk->led_gpio, 0);
}

static int skl_int3472_clk_enable(struct clk_hw *hw)
diff --git a/drivers/platform/x86/intel/int3472/common.h b/drivers/platform/x86/intel/int3472/common.h
index 53270d19c73a..e106bbfe8ffa 100644
--- a/drivers/platform/x86/intel/int3472/common.h
+++ b/drivers/platform/x86/intel/int3472/common.h
@@ -6,6 +6,7 @@

#include <linux/clk-provider.h>
#include <linux/gpio/machine.h>
+#include <linux/leds.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/types.h>
@@ -28,6 +29,8 @@
#define GPIO_REGULATOR_NAME_LENGTH 21
#define GPIO_REGULATOR_SUPPLY_NAME_LENGTH 9

+#define INT3472_LED_MAX_NAME_LEN 32
+
#define CIO2_SENSOR_SSDB_MCLKSPEED_OFFSET 86

#define INT3472_REGULATOR(_name, _supply, _ops) \
@@ -96,10 +99,16 @@ struct int3472_discrete_device {
struct clk_hw clk_hw;
struct clk_lookup *cl;
struct gpio_desc *ena_gpio;
- struct gpio_desc *led_gpio;
u32 frequency;
} clock;

+ struct int3472_pled {
+ char name[INT3472_LED_MAX_NAME_LEN];
+ struct led_lookup_data lookup;
+ struct led_classdev classdev;
+ struct gpio_desc *gpio;
+ } pled;
+
unsigned int ngpios; /* how many GPIOs have we seen */
unsigned int n_sensor_gpios; /* how many have we mapped to sensor */
struct gpiod_lookup_table gpios;
@@ -119,4 +128,8 @@ int skl_int3472_register_regulator(struct int3472_discrete_device *int3472,
struct acpi_resource_gpio *agpio);
void skl_int3472_unregister_regulator(struct int3472_discrete_device *int3472);

+int skl_int3472_register_pled(struct int3472_discrete_device *int3472,
+ struct acpi_resource_gpio *agpio, u32 polarity);
+void skl_int3472_unregister_pled(struct int3472_discrete_device *int3472);
+
#endif
diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
index bd3797ce64bf..1a1e0b196bfa 100644
--- a/drivers/platform/x86/intel/int3472/discrete.c
+++ b/drivers/platform/x86/intel/int3472/discrete.c
@@ -155,33 +155,19 @@ static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int347
}

static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
- struct acpi_resource_gpio *agpio, u8 type)
+ struct acpi_resource_gpio *agpio)
{
char *path = agpio->resource_source.string_ptr;
u16 pin = agpio->pin_table[0];
struct gpio_desc *gpio;

- switch (type) {
- case INT3472_GPIO_TYPE_CLK_ENABLE:
- gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
- if (IS_ERR(gpio))
- return (PTR_ERR(gpio));
-
- int3472->clock.ena_gpio = gpio;
- break;
- case INT3472_GPIO_TYPE_PRIVACY_LED:
- gpio = acpi_get_and_request_gpiod(path, pin, "int3472,privacy-led");
- if (IS_ERR(gpio))
- return (PTR_ERR(gpio));
+ gpio = acpi_get_and_request_gpiod(path, pin, "int3472,clk-enable");
+ if (IS_ERR(gpio))
+ return (PTR_ERR(gpio));

- int3472->clock.led_gpio = gpio;
- break;
- default:
- dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
- break;
- }
+ int3472->clock.ena_gpio = gpio;

- return 0;
+ return skl_int3472_register_clock(int3472);
}

static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
@@ -289,11 +275,16 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,

break;
case INT3472_GPIO_TYPE_CLK_ENABLE:
- case INT3472_GPIO_TYPE_PRIVACY_LED:
- ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
+ ret = skl_int3472_map_gpio_to_clk(int3472, agpio);
if (ret)
err_msg = "Failed to map GPIO to clock\n";

+ break;
+ case INT3472_GPIO_TYPE_PRIVACY_LED:
+ ret = skl_int3472_register_pled(int3472, agpio, polarity);
+ if (ret)
+ err_msg = "Failed to register LED\n";
+
break;
case INT3472_GPIO_TYPE_POWER_ENABLE:
ret = skl_int3472_register_regulator(int3472, agpio);
@@ -337,21 +328,6 @@ static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)

acpi_dev_free_resource_list(&resource_list);

- /*
- * If we find no clock enable GPIO pin then the privacy LED won't work.
- * We've never seen that situation, but it's possible. Warn the user so
- * it's clear what's happened.
- */
- if (int3472->clock.ena_gpio) {
- ret = skl_int3472_register_clock(int3472);
- if (ret)
- return ret;
- } else {
- if (int3472->clock.led_gpio)
- dev_warn(int3472->dev,
- "No clk GPIO. The privacy LED won't work\n");
- }
-
int3472->gpios.dev_id = int3472->sensor_name;
gpiod_add_lookup_table(&int3472->gpios);

@@ -368,8 +344,8 @@ static int skl_int3472_discrete_remove(struct platform_device *pdev)
skl_int3472_unregister_clock(int3472);

gpiod_put(int3472->clock.ena_gpio);
- gpiod_put(int3472->clock.led_gpio);

+ skl_int3472_unregister_pled(int3472);
skl_int3472_unregister_regulator(int3472);

return 0;
diff --git a/drivers/platform/x86/intel/int3472/led.c b/drivers/platform/x86/intel/int3472/led.c
new file mode 100644
index 000000000000..05c58ba23570
--- /dev/null
+++ b/drivers/platform/x86/intel/int3472/led.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Author: Hans de Goede <hdegoede@redhat.com> */
+
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/leds.h>
+#include "common.h"
+
+static int int3472_register_pled_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ struct int3472_discrete_device *int3472 =
+ container_of(led_cdev, struct int3472_discrete_device, pled.classdev);
+
+ gpiod_set_value_cansleep(int3472->pled.gpio, brightness);
+ return 0;
+}
+
+int skl_int3472_register_pled(struct int3472_discrete_device *int3472,
+ struct acpi_resource_gpio *agpio, u32 polarity)
+{
+ char *path = agpio->resource_source.string_ptr;
+ int i, ret;
+
+ if (int3472->pled.classdev.dev)
+ return -EBUSY;
+
+ int3472->pled.gpio = acpi_get_and_request_gpiod(path, agpio->pin_table[0],
+ "int3472,privacy-led");
+ if (IS_ERR(int3472->pled.gpio)) {
+ ret = PTR_ERR(int3472->pled.gpio);
+ return dev_err_probe(int3472->dev, ret, "getting privacy LED GPIO\n");
+ }
+
+ if (polarity == GPIO_ACTIVE_LOW)
+ gpiod_toggle_active_low(int3472->pled.gpio);
+
+ /* Ensure the pin is in output mode and non-active state */
+ gpiod_direction_output(int3472->pled.gpio, 0);
+
+ /* Generate the name, replacing the ':' in the ACPI devname with '_' */
+ snprintf(int3472->pled.name, sizeof(int3472->pled.name),
+ "%s::privacy_led", acpi_dev_name(int3472->sensor));
+ for (i = 0; int3472->pled.name[i]; i++) {
+ if (int3472->pled.name[i] == ':') {
+ int3472->pled.name[i] = '_';
+ break;
+ }
+ }
+
+ int3472->pled.classdev.name = int3472->pled.name;
+ int3472->pled.classdev.max_brightness = 1;
+ int3472->pled.classdev.brightness_set_blocking = int3472_register_pled_set;
+
+ ret = led_classdev_register(int3472->dev, &int3472->pled.classdev);
+ if (ret)
+ goto err_free_gpio;
+
+ int3472->pled.lookup.led_name = int3472->pled.name;
+ int3472->pled.lookup.consumer_dev_name = int3472->sensor_name;
+ int3472->pled.lookup.consumer_function = "privacy-led";
+ led_add_lookup(&int3472->pled.lookup);
+
+ return 0;
+
+err_free_gpio:
+ gpiod_put(int3472->pled.gpio);
+ return ret;
+}
+
+void skl_int3472_unregister_pled(struct int3472_discrete_device *int3472)
+{
+ if (IS_ERR_OR_NULL(int3472->pled.classdev.dev))
+ return;
+
+ led_remove_lookup(&int3472->pled.lookup);
+ led_classdev_unregister(&int3472->pled.classdev);
+ gpiod_put(int3472->pled.gpio);
+}
--
2.38.1