Patch set updated for coreboot: i2c/generic: Add support for passing reset-gpio in ACPI

[Furquan Shaikh]

Furquan Shaikh ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/16872

-gerrit

commit 58c21f0db095172cf5f76323a4140d3e9a2b7a90
Author: Furquan Shaikh 
Date:   Mon Oct 3 23:43:06 2016 -0700

i2c/generic: Add support for passing reset-gpio in ACPI

There are two things required to pass reset-gpio via ACPI:
    1. Add GPIO to _CRS
    2. Add reset-gpio property in _DSD with index in _CRS to the
    corresponding gpio.

Implement function to add gpio to _CRS and return appropriate index. This can
    be useful if later we need to add more gpio properties with appropriate
    indices.

BUG=chrome-os-partner:55988
    BRANCH=None
    TEST=Verified that reset-gpio property appears in SSDT on reef.

Change-Id: Ibbf7d6f3916fb43bd722de21391e635c07dd81f7
    Signed-off-by: Furquan Shaikh 
---
 src/drivers/i2c/generic/chip.h    |  3 +++
 src/drivers/i2c/generic/generic.c | 34 ++++++++++++++++++++++++++++++----
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/src/drivers/i2c/generic/chip.h b/src/drivers/i2c/generic/chip.h
index d84097f..7e319b4 100644
--- a/src/drivers/i2c/generic/chip.h
+++ b/src/drivers/i2c/generic/chip.h
@@ -22,4 +22,7 @@ struct drivers_i2c_generic_config {
    /* GPIO used to indicate if this device is present */
    unsigned device_present_gpio;
    unsigned device_present_gpio_invert;
+
+	/* GPIO used to reset the device. */
+	struct acpi_gpio reset_gpio;
 };
diff --git a/src/drivers/i2c/generic/generic.c b/src/drivers/i2c/generic/generic.c
index 30a280b..a8b5dfa 100644
--- a/src/drivers/i2c/generic/generic.c
+++ b/src/drivers/i2c/generic/generic.c
@@ -25,6 +25,21 @@
 #include "chip.h"

#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+
+static int i2c_generic_device_write_gpio(struct acpi_gpio *gpio)
+{
+	static int gpio_index = 0;
+	int ret = -1;
+
+	if (gpio->pin_count) {
+		acpi_device_write_gpio(gpio);
+		ret = gpio_index;
+		gpio_index++;
+	}
+
+	return ret;
+}
+
 static void i2c_generic_fill_ssdt(struct device *dev)
 {
    struct drivers_i2c_generic_config *config = dev->chip_info;
@@ -36,6 +51,8 @@ static void i2c_generic_fill_ssdt(struct device *dev)
    	.resource = scope,
    };
    struct acpi_dp *dsd = NULL;
+	int reset_index;
+	const char *path = acpi_device_path(dev);

if (!dev->enabled || !scope)
    	return;
@@ -58,6 +75,7 @@ static void i2c_generic_fill_ssdt(struct device *dev)
    acpigen_write_resourcetemplate_header();
    acpi_device_write_i2c(&i2c);
    acpi_device_write_interrupt(&config->irq);
+	reset_index = i2c_generic_device_write_gpio(&config->reset_gpio);
    acpigen_write_resourcetemplate_footer();

/* Wake capabilities */
@@ -66,16 +84,24 @@ static void i2c_generic_fill_ssdt(struct device *dev)
    	acpigen_write_PRW(config->wake, 3);
    }

-	if (config->probed) {
+	/* Device-specific data */
+	/* Decide if _DSD is required. */
+	if (config->probed || (reset_index != -1))
    	dsd = acpi_dp_new_table("_DSD");
-		acpi_dp_add_integer(dsd, "linux,probed", 1);
+
+	acpi_dp_add_integer(dsd, "linux,probed", config->probed);
+
+	if (reset_index != -1)
+		acpi_dp_add_gpio(dsd, "reset-gpio", path, reset_index, 0,
+				 config->reset_gpio.polarity);
+
+	if (dsd)
    	acpi_dp_write(dsd);
-	}

acpigen_pop_len(); /* Device */
    acpigen_pop_len(); /* Scope */

-	printk(BIOS_INFO, "%s: %s at %s\n", acpi_device_path(dev),
+	printk(BIOS_INFO, "%s: %s at %s\n", path,
           config->desc ? : dev->chip_ops->name, dev_path(dev));
 }