skylake: Add SD card device to configure card detect GPIO

Add a PCI driver for the skylake SD card device and have it generate
an entry in the SSDT for the card detect GPIO if it is provided by the
mainboard in devicetree.

This sets up a card detect GPIO configuration that will trigger an
interrupt on both edges with a 100ms debounce timeout and can wake the
SD controller from D3 state.

The GpioInt() entry is bound to the "cd-gpio" device property which will
be consumed by the kernel driver.

The resulting ACPI output in the SSDT will be combined with the SDXC
device declaration in the DSDT.

Example:

Scope (\_SB.PCI0.SDXC)
{
  Name (_CRS, ResourceTemplate () {
    GpioInt (Edge, ActiveBoth, SharedAndWake, PullNone, 10000,
             "\\_SB.PCI0.GPIO", 0, ResourceConsumer) { 35 }
  })
  Name (_DSD, Package () {
    ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
    Package () {
      Package () { "cd-gpio", Package () { \_SB.PCI0.SDXC, 0, 0, 1 } }
    }
  })
}

Change-Id: Ie4c1bfadd962cf55a987edb9ef86e92174205770
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/14995
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/skylake/Makefile.inc

@@ -53,6 +53,7 @@ ramstage-y += pei_data.c
 ramstage-y += pmc.c
 ramstage-y += pmutil.c
 ramstage-y += ramstage.c
+ramstage-y += sd.c
 ramstage-y += smbus.c
 ramstage-y += smbus_common.c
 ramstage-y += smi.c

src/soc/intel/skylake/chip.h

@@ -19,6 +19,7 @@
 #ifndef _SOC_CHIP_H_
 #define _SOC_CHIP_H_
 
+#include <arch/acpi_device.h>
 #include <stdint.h>
 #include <soc/gpio_defs.h>
 #include <soc/gpe.h>
@@ -339,6 +340,23 @@ struct soc_intel_skylake_config {
 	u8 SendVrMbxCmd;
 	/* Statically clock gate 8254 PIT. */
 	u8 clock_gate_8254;
+
+	/*
+	 * Use SD card detect GPIO with default config:
+	 * - Edge triggered
+	 * - No internal pull
+	 * - Active both (high + low)
+	 * - Can wake device from D3
+	 * - 100ms debounce timeout
+	 *
+	 * GpioInt (Edge, ActiveBoth, SharedAndWake, PullNone, 10000,
+	 *          "\\_SB.PCI0.GPIO", 0, ResourceConsumer)
+	 *          { sdcard_cd_gpio_default }
+	 */
+	unsigned sdcard_cd_gpio_default;
+
+	/* Use custom SD card detect GPIO configuration */
+	struct acpi_gpio sdcard_cd_gpio;
 };
 
 typedef struct soc_intel_skylake_config config_t;

src/soc/intel/skylake/sd.c

@@ -0,0 +1,87 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/acpi_device.h>
+#include <arch/acpigen.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <gpio.h>
+#include <soc/ramstage.h>
+#include "chip.h"
+
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+static void sd_fill_ssdt(struct device *dev)
+{
+	config_t *config = dev->chip_info;
+	const char *path;
+	struct acpi_gpio default_gpio = {
+		.type = ACPI_GPIO_TYPE_INTERRUPT,
+		.pull = ACPI_GPIO_PULL_NONE,
+		.irq.mode = IRQ_EDGE_TRIGGERED,
+		.irq.polarity = IRQ_ACTIVE_BOTH,
+		.irq.shared = IRQ_SHARED,
+		.irq.wake = IRQ_WAKE,
+		.interrupt_debounce_timeout = 10000, /* 100ms */
+		.pin_count = 1,
+		.pins = { config->sdcard_cd_gpio_default }
+	};
+
+	if (!dev->enabled)
+		return;
+
+	/* Nothing to write if GPIO is not set in devicetree */
+	if (!config->sdcard_cd_gpio_default && !config->sdcard_cd_gpio.pins[0])
+		return;
+
+	/* Use device path as the Scope for the SSDT */
+	path = acpi_device_path(dev);
+	if (!path)
+		return;
+	acpigen_write_scope(path);
+	acpigen_write_name("_CRS");
+
+	/* Write GpioInt() as default (if set) or custom from devicetree */
+	acpigen_write_resourcetemplate_header();
+	if (config->sdcard_cd_gpio_default)
+		acpi_device_write_gpio(&default_gpio);
+	else
+		acpi_device_write_gpio(&config->sdcard_cd_gpio);
+	acpigen_write_resourcetemplate_footer();
+
+	/* Bind the cd-gpio name to the GpioInt() resource */
+	acpi_dp_write_header();
+	acpi_dp_write_gpio("cd-gpio", path, 0, 0, 1);
+	acpi_dp_write_footer();
+
+	acpigen_pop_len();
+}
+#endif
+
+static struct device_operations dev_ops = {
+	.read_resources		  = &pci_dev_read_resources,
+	.set_resources		  = &pci_dev_set_resources,
+	.enable_resources	  = &pci_dev_enable_resources,
+	.ops_pci		  = &soc_pci_ops,
+#if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+	.acpi_fill_ssdt_generator = &sd_fill_ssdt,
+#endif
+};
+
+static const struct pci_driver pch_sd __pci_driver = {
+	.ops	= &dev_ops,
+	.vendor	= PCI_VENDOR_ID_INTEL,
+	.device	= 0x9d2d
+};