[PATCH v4] mmc: sdhci-pci: Add DMI quirk for missing CD GPIO on Vexia Edu Atla 10 tablet

[Hans de Goede <hdegoede@redhat.com>]

The Vexia Edu Atla 10 tablet distributed to schools in the Spanish
Andalucía region has no ACPI fwnode associated with the SDHCI controller
for its microsd-slot and thus has no ACPI GPIO resource info.

This causes the following error to be logged and the slot to not work:
[   10.572113] sdhci-pci 0000:00:12.0: failed to setup card detect gpio

Add a DMI quirk table for providing gpiod_lookup_tables with manually
provided CD GPIO info and use this DMI table to provide the CD GPIO info
on this tablet. This fixes the microsd-slot not working.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v4:
- Count number of GPIOs in the lookup table instead of assuming it is
  always 1

Changes in v3:
- Add a cd_gpio_override pointer to sdhci_pci_fixes
- Add sdhci_pci_add_gpio_lookup_table() helper which kmemdup-s a const
  struct gpiod_lookup_table to avoid races when using async probing

Changes in v2:
- Make sdhci_pci_dmi_cd_gpio_overrides static const instead of just const
- Drop duplicate #include <linux/dmi.h> (already there at the end)
---
 drivers/mmc/host/sdhci-pci-core.c | 72 +++++++++++++++++++++++++++++++
 drivers/mmc/host/sdhci-pci.h      |  1 +
 2 files changed, 73 insertions(+)

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index ed45ed0bdafd..2e2e15e2d8fb 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -21,6 +21,7 @@
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm_qos.h>
 #include <linux/debugfs.h>
@@ -1235,6 +1236,29 @@ static const struct sdhci_pci_fixes sdhci_intel_byt_sdio = {
 	.priv_size	= sizeof(struct intel_host),
 };
 
+/* DMI quirks for devices with missing or broken CD GPIO info */
+static const struct gpiod_lookup_table vexia_edu_atla10_cd_gpios = {
+	.dev_id = "0000:00:12.0",
+	.table = {
+		GPIO_LOOKUP("INT33FC:00", 38, "cd", GPIO_ACTIVE_HIGH),
+		{ }
+	},
+};
+
+static const struct dmi_system_id sdhci_intel_byt_cd_gpio_override[] = {
+	{
+		/* Vexia Edu Atla 10 tablet 9V version */
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
+			DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
+			/* Above strings are too generic, also match on BIOS date */
+			DMI_MATCH(DMI_BIOS_DATE, "08/25/2014"),
+		},
+		.driver_data = (void *)&vexia_edu_atla10_cd_gpios,
+	},
+	{ }
+};
+
 static const struct sdhci_pci_fixes sdhci_intel_byt_sd = {
 #ifdef CONFIG_PM_SLEEP
 	.resume		= byt_resume,
@@ -1253,6 +1277,7 @@ static const struct sdhci_pci_fixes sdhci_intel_byt_sd = {
 	.add_host	= byt_add_host,
 	.remove_slot	= byt_remove_slot,
 	.ops		= &sdhci_intel_byt_ops,
+	.cd_gpio_override = sdhci_intel_byt_cd_gpio_override,
 	.priv_size	= sizeof(struct intel_host),
 };
 
@@ -2054,6 +2079,42 @@ static const struct dev_pm_ops sdhci_pci_pm_ops = {
  *                                                                           *
 \*****************************************************************************/
 
+static struct gpiod_lookup_table *sdhci_pci_add_gpio_lookup_table(
+	struct sdhci_pci_chip *chip)
+{
+	struct gpiod_lookup_table *cd_gpio_lookup_table;
+	const struct dmi_system_id *dmi_id = NULL;
+	size_t count;
+
+	if (chip->fixes && chip->fixes->cd_gpio_override)
+		dmi_id = dmi_first_match(chip->fixes->cd_gpio_override);
+
+	if (!dmi_id)
+		return NULL;
+
+	cd_gpio_lookup_table = dmi_id->driver_data;
+	for (count = 0; cd_gpio_lookup_table->table[count].key; count++)
+		;
+
+	cd_gpio_lookup_table = kmemdup(dmi_id->driver_data,
+				       /* count + 1 terminating entry */
+				       struct_size(cd_gpio_lookup_table, table, count + 1),
+				       GFP_KERNEL);
+	if (!cd_gpio_lookup_table)
+		return ERR_PTR(-ENOMEM);
+
+	gpiod_add_lookup_table(cd_gpio_lookup_table);
+	return cd_gpio_lookup_table;
+}
+
+static void sdhci_pci_remove_gpio_lookup_table(struct gpiod_lookup_table *lookup_table)
+{
+	if (lookup_table) {
+		gpiod_remove_lookup_table(lookup_table);
+		kfree(lookup_table);
+	}
+}
+
 static struct sdhci_pci_slot *sdhci_pci_probe_slot(
 	struct pci_dev *pdev, struct sdhci_pci_chip *chip, int first_bar,
 	int slotno)
@@ -2129,8 +2190,19 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot(
 		device_init_wakeup(&pdev->dev, true);
 
 	if (slot->cd_idx >= 0) {
+		struct gpiod_lookup_table *cd_gpio_lookup_table;
+
+		cd_gpio_lookup_table = sdhci_pci_add_gpio_lookup_table(chip);
+		if (IS_ERR(cd_gpio_lookup_table)) {
+			ret = PTR_ERR(cd_gpio_lookup_table);
+			goto remove;
+		}
+
 		ret = mmc_gpiod_request_cd(host->mmc, "cd", slot->cd_idx,
 					   slot->cd_override_level, 0);
+
+		sdhci_pci_remove_gpio_lookup_table(cd_gpio_lookup_table);
+
 		if (ret && ret != -EPROBE_DEFER)
 			ret = mmc_gpiod_request_cd(host->mmc, NULL,
 						   slot->cd_idx,
diff --git a/drivers/mmc/host/sdhci-pci.h b/drivers/mmc/host/sdhci-pci.h
index 153704f812ed..4973fa859217 100644
--- a/drivers/mmc/host/sdhci-pci.h
+++ b/drivers/mmc/host/sdhci-pci.h
@@ -156,6 +156,7 @@ struct sdhci_pci_fixes {
 #endif
 
 	const struct sdhci_ops	*ops;
+	const struct dmi_system_id *cd_gpio_override;
 	size_t			priv_size;
 };
 
-- 
2.47.0