mfd: arizona: Add support for ACPI enumeration of WM5102 connected over SPI

The Intel Bay Trail (x86/ACPI) based Lenovo Yoga Tablet 2 series use
a WM5102 codec connected over SPI.

Add support for ACPI enumeration to arizona-spi so that arizona-spi can
bind to the codec on these tablets.

This is loosely based on an earlier attempt (for Android-x86) at this by
Christian Hartmann, combined with insights in things like the speaker GPIO
from the android-x86 android port for the Lenovo Yoga Tablet 2 1051F/L [1].

[1] https://github.com/Kitsune2222/Android_Yoga_Tablet_2-1051F_Kernel

Cc: Christian Hartmann <cornogle@googlemail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/mfd/arizona-spi.c b/drivers/mfd/arizona-spi.c
index 798b88295c7742403139e4f2793406801275c781..24a2c75d691a4e3c186ba2c840bdecfc3e1d0dd7 100644 (file)
--- a/drivers/mfd/arizona-spi.c
+++ b/drivers/mfd/arizona-spi.c
@@ -7,7 +7,10 @@
  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  */
 
+#include <linux/acpi.h>
 #include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/machine.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
@@ -15,11 +18,128 @@
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
 #include <linux/of.h>
+#include <uapi/linux/input-event-codes.h>
 
 #include <linux/mfd/arizona/core.h>
 
 #include "arizona.h"
 
+#ifdef CONFIG_ACPI
+const struct acpi_gpio_params reset_gpios = { 1, 0, false };
+const struct acpi_gpio_params ldoena_gpios = { 2, 0, false };
+
+static const struct acpi_gpio_mapping arizona_acpi_gpios[] = {
+       { "reset-gpios", &reset_gpios, 1, },
+       { "wlf,ldoena-gpios", &ldoena_gpios, 1 },
+       { }
+};
+
+/*
+ * The ACPI resources for the device only describe external GPIO-s. They do
+ * not provide mappings for the GPIO-s coming from the Arizona codec itself.
+ */
+static const struct gpiod_lookup arizona_soc_gpios[] = {
+       { "arizona", 2, "wlf,spkvdd-ena", 0, GPIO_ACTIVE_HIGH },
+       { "arizona", 4, "wlf,micd-pol", 0, GPIO_ACTIVE_LOW },
+};
+
+/*
+ * The AOSP 3.5 mm Headset: Accessory Specification gives the following values:
+ * Function A Play/Pause:           0 ohm
+ * Function D Voice assistant:    135 ohm
+ * Function B Volume Up           240 ohm
+ * Function C Volume Down         470 ohm
+ * Minimum Mic DC resistance     1000 ohm
+ * Minimum Ear speaker impedance   16 ohm
+ * Note the first max value below must be less then the min. speaker impedance,
+ * to allow CTIA/OMTP detection to work. The other max values are the closest
+ * value from extcon-arizona.c:arizona_micd_levels halfway 2 button resistances.
+ */
+static const struct arizona_micd_range arizona_micd_aosp_ranges[] = {
+       { .max =  11, .key = KEY_PLAYPAUSE },
+       { .max = 186, .key = KEY_VOICECOMMAND },
+       { .max = 348, .key = KEY_VOLUMEUP },
+       { .max = 752, .key = KEY_VOLUMEDOWN },
+};
+
+static void arizona_spi_acpi_remove_lookup(void *lookup)
+{
+       gpiod_remove_lookup_table(lookup);
+}
+
+static int arizona_spi_acpi_probe(struct arizona *arizona)
+{
+       struct gpiod_lookup_table *lookup;
+       acpi_status status;
+       int ret;
+
+       /* Add mappings for the 2 ACPI declared GPIOs used for reset and ldo-ena */
+       devm_acpi_dev_add_driver_gpios(arizona->dev, arizona_acpi_gpios);
+
+       /* Add lookups for the SoCs own GPIOs used for micdet-polarity and spkVDD-enable */
+       lookup = devm_kzalloc(arizona->dev,
+                             struct_size(lookup, table, ARRAY_SIZE(arizona_soc_gpios) + 1),
+                             GFP_KERNEL);
+       if (!lookup)
+               return -ENOMEM;
+
+       lookup->dev_id = dev_name(arizona->dev);
+       memcpy(lookup->table, arizona_soc_gpios, sizeof(arizona_soc_gpios));
+
+       gpiod_add_lookup_table(lookup);
+       ret = devm_add_action_or_reset(arizona->dev, arizona_spi_acpi_remove_lookup, lookup);
+       if (ret)
+               return ret;
+
+       /* Enable 32KHz clock from SoC to codec for jack-detect */
+       status = acpi_evaluate_object(ACPI_HANDLE(arizona->dev), "CLKE", NULL, NULL);
+       if (ACPI_FAILURE(status))
+               dev_warn(arizona->dev, "Failed to enable 32KHz clk ACPI error %d\n", status);
+
+       /*
+        * Some DSDTs wrongly declare the IRQ trigger-type as IRQF_TRIGGER_FALLING
+        * The IRQ line will stay low when a new IRQ event happens between reading
+        * the IRQ status flags and acknowledging them. When the IRQ line stays
+        * low like this the IRQ will never trigger again when its type is set
+        * to IRQF_TRIGGER_FALLING. Correct the IRQ trigger-type to fix this.
+        *
+        * Note theoretically it is possible that some boards are not capable
+        * of handling active low level interrupts. In that case setting the
+        * flag to IRQF_TRIGGER_FALLING would not be a bug (and we would need
+        * to work around this) but so far all known usages of IRQF_TRIGGER_FALLING
+        * are a bug in the board's DSDT.
+        */
+       arizona->pdata.irq_flags = IRQF_TRIGGER_LOW;
+
+       /* Wait 200 ms after jack insertion */
+       arizona->pdata.micd_detect_debounce = 200;
+
+       /* Use standard AOSP values for headset-button mappings */
+       arizona->pdata.micd_ranges = arizona_micd_aosp_ranges;
+       arizona->pdata.num_micd_ranges = ARRAY_SIZE(arizona_micd_aosp_ranges);
+
+       return 0;
+}
+
+static const struct acpi_device_id arizona_acpi_match[] = {
+       {
+               .id = "WM510204",
+               .driver_data = WM5102,
+       },
+       {
+               .id = "WM510205",
+               .driver_data = WM5102,
+       },
+       { }
+};
+MODULE_DEVICE_TABLE(acpi, arizona_acpi_match);
+#else
+static int arizona_spi_acpi_probe(struct arizona *arizona)
+{
+       return -ENODEV;
+}
+#endif
+
 static int arizona_spi_probe(struct spi_device *spi)
 {
        const struct spi_device_id *id = spi_get_device_id(spi);
@@ -77,6 +197,12 @@ static int arizona_spi_probe(struct spi_device *spi)
        arizona->dev = &spi->dev;
        arizona->irq = spi->irq;
 
+       if (has_acpi_companion(&spi->dev)) {
+               ret = arizona_spi_acpi_probe(arizona);
+               if (ret)
+                       return ret;
+       }
+
        return arizona_dev_init(arizona);
 }
 
@@ -104,6 +230,7 @@ static struct spi_driver arizona_spi_driver = {
                .name   = "arizona",
                .pm     = &arizona_pm_ops,
                .of_match_table = of_match_ptr(arizona_of_match),
+               .acpi_match_table = ACPI_PTR(arizona_acpi_match),
        },
        .probe          = arizona_spi_probe,
        .remove         = arizona_spi_remove,