Re: [PATCH 3/4] Input: icn8318 - Add support for ACPI enumeration
From: Hans de Goede <hidden>
Date: 2017-06-17 20:09:56
Hi, Self-nack see comment inline. On 17-06-17 12:58, Hans de Goede wrote:
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The icn8505 variant is found on some x86 tablets, which use ACPI enumeration, add support for ACPI enumeration. Signed-off-by: Hans de Goede <redacted> --- drivers/input/touchscreen/Kconfig | 2 +- drivers/input/touchscreen/chipone_icn8318.c | 67 ++++++++++++++++++++++++++++- 2 files changed, 67 insertions(+), 2 deletions(-)diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig index fff1467506e7..e3b52d356e13 100644 --- a/drivers/input/touchscreen/Kconfig +++ b/drivers/input/touchscreen/Kconfig@@ -155,7 +155,7 @@ config TOUCHSCREEN_CHIPONE_ICN8318 tristate "chipone icn8318 touchscreen controller" depends on GPIOLIB || COMPILE_TEST depends on I2C - depends on OF + depends on OF || ACPI help Say Y here if you have a ChipOne icn8318 or icn8505 based I2C touchscreen.diff --git a/drivers/input/touchscreen/chipone_icn8318.c b/drivers/input/touchscreen/chipone_icn8318.c index 993df804883f..b209872954f7 100644 --- a/drivers/input/touchscreen/chipone_icn8318.c +++ b/drivers/input/touchscreen/chipone_icn8318.c@@ -12,6 +12,7 @@ * Hans de Goede <hdegoede@redhat.com> */ +#include <linux/acpi.h> #include <linux/gpio/consumer.h> #include <linux/interrupt.h> #include <linux/i2c.h>@@ -232,6 +233,66 @@ static int icn8318_probe_of(struct icn8318_data *data, struct device *dev) } #endif +#ifdef CONFIG_ACPI +static const struct acpi_device_id icn8318_acpi_match[] = { + { "CHPN0001", ICN8505 }, + { } +}; +MODULE_DEVICE_TABLE(acpi, icn8318_acpi_match); + +static int icn8318_probe_acpi(struct icn8318_data *data, struct device *dev) +{ + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; + struct input_dev *input = data->input; + const struct acpi_device_id *id; + struct acpi_device *adev; + acpi_status status; + const char *sub; + + adev = ACPI_COMPANION(dev); + id = acpi_match_device(icn8318_acpi_match, dev); + if (!adev || !id) + return -ENODEV; + + data->model = id->driver_data; + + /* The _SUB ACPI object describes the touchscreen model */ + status = acpi_evaluate_object_typed(adev->handle, "_SUB", NULL, + &buf, ACPI_TYPE_STRING); + if (ACPI_FAILURE(status)) { + dev_err(dev, "ACPI _SUB object not found\n"); + return -ENODEV; + } + sub = ((union acpi_object *)buf.pointer)->string.pointer; + + if (strcmp(sub, "HAMP0002") == 0) { + input_set_abs_params(input, ABS_MT_POSITION_X, 0, 1199, 0, 0); + input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 1919, 0, 0); + } else { + dev_err(dev, "Unknown model _SUB: %s\n", sub); + kfree(buf.pointer); + return -ENODEV; + } + kfree(buf.pointer); + + /* + * Disable ACPI power management the _PS3 method is empty, so + * there is no powersaving when using ACPI power management. + * The _PS0 method resets the controller causing it to loose its + * firmware, which has been loaded by the BIOS and we do not + * know how to restore the firmware. + */ + adev->flags.power_manageable = 0;
Ok, so unfortunately this is not that easy :| The ACPI node has a _CID, "PNP0C50" causing i2c-hid to bind, even though the device has its own device specific protocol. I had i2c-hid blacklisted for testing, with the plan to add a quirk to it for this device, but with the quirk if i2c-hid loads earlier then the icn8318 driver and i2c-hid's probe returns -ENODEV due to the quirk, the device gets turned off by the ACPI core, causing a reset + loss of the loaded firmware when the icn8313 driver loads. So there are 2 solutions here: 1) Set adev->flags.power_manageable earlier, somewhere in the ACPI core 2) Figure out how to load the firmware to make the controller functional again Regards, Hans
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+ + return 0; +} +#else +static int icn8318_probe_acpi(struct icn8318_data *data, struct device *dev) +{ + return -ENODEV; +} +#endif + static int icn8318_probe(struct i2c_client *client) { struct device *dev = &client->dev;@@ -264,7 +325,10 @@ static int icn8318_probe(struct i2c_client *client) input_set_capability(input, EV_ABS, ABS_MT_POSITION_X); input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y); - error = icn8318_probe_of(data, dev); + if (client->dev.of_node) + error = icn8318_probe_of(data, dev); + else + error = icn8318_probe_acpi(data, dev); if (error) return error;@@ -318,6 +382,7 @@ static struct i2c_driver icn8318_driver = { .driver = { .name = "chipone_icn8318", .pm = &icn8318_pm_ops, + .acpi_match_table = ACPI_PTR(icn8318_acpi_match), .of_match_table = icn8318_of_match, }, .probe_new = icn8318_probe,