platform/x86: int3472/discrete: Create a LED class device for the privacy LED

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>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://lore.kernel.org/r/20230127203729.10205-4-hdegoede@redhat.com

diff --git a/drivers/platform/x86/intel/int3472/Makefile b/drivers/platform/x86/intel/int3472/Makefile
index cfec778..9f16cb5 100644 (file)
--- 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 74dc2cf..e3b597d 100644 (file)
--- 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 53270d1..82dc37e 100644 (file)
--- 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 {
+               struct led_classdev classdev;
+               struct led_lookup_data lookup;
+               char name[INT3472_LED_MAX_NAME_LEN];
+               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 708d51f..38b1372 100644 (file)
--- a/drivers/platform/x86/intel/int3472/discrete.c
+++ b/drivers/platform/x86/intel/int3472/discrete.c
@@ -155,37 +155,21 @@ 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;
-               /* Ensure the pin is in output mode and non-active state */
-               gpiod_direction_output(int3472->clock.ena_gpio, 0);
-               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;
-               /* Ensure the pin is in output mode and non-active state */
-               gpiod_direction_output(int3472->clock.led_gpio, 0);
-               break;
-       default:
-               dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
-               break;
-       }
+       int3472->clock.ena_gpio = gpio;
+       /* Ensure the pin is in output mode and non-active state */
+       gpiod_direction_output(int3472->clock.ena_gpio, 0);
 
-       return 0;
+       return skl_int3472_register_clock(int3472);
 }
 
 static void int3472_get_func_and_polarity(u8 type, const char **func, u32 *polarity)
@@ -293,12 +277,17 @@ 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);
                if (ret)
@@ -341,21 +330,6 @@ 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);
 
@@ -372,8 +346,8 @@ 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 (file)
index 0000000..bca1ce7
--- /dev/null
+++ b/drivers/platform/x86/intel/int3472/led.c
@@ -0,0 +1,75 @@
+// 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_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 *p, *path = agpio->resource_source.string_ptr;
+       int 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))
+               return dev_err_probe(int3472->dev, PTR_ERR(int3472->pled.gpio),
+                                    "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));
+       p = strchr(int3472->pled.name, ':');
+       if (p)
+               *p = '_';
+
+       int3472->pled.classdev.name = int3472->pled.name;
+       int3472->pled.classdev.max_brightness = 1;
+       int3472->pled.classdev.brightness_set_blocking = int3472_pled_set;
+
+       ret = led_classdev_register(int3472->dev, &int3472->pled.classdev);
+       if (ret)
+               goto err_free_gpio;
+
+       int3472->pled.lookup.provider = int3472->pled.name;
+       int3472->pled.lookup.dev_id = int3472->sensor_name;
+       int3472->pled.lookup.con_id = "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);
+}