1 files changed, 113 insertions, 16 deletions

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 12f12da3e4f3..effcafbc09bf 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -108,6 +108,84 @@ static const struct i2c_device_id pca953x_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, pca953x_id);
 
+#ifdef CONFIG_GPIO_PCA953X_IRQ
+
+#include <linux/dmi.h>
+#include <linux/gpio.h>
+#include <linux/list.h>
+
+static const struct dmi_system_id pca953x_dmi_acpi_irq_info[] = {
+	{
+		/*
+		 * On Intel Galileo Gen 2 board the IRQ pin of one of
+		 * the I²C GPIO expanders, which has GpioInt() resource,
+		 * is provided as an absolute number instead of being
+		 * relative. Since first controller (gpio-sch.c) and
+		 * second (gpio-dwapb.c) are at the fixed bases, we may
+		 * safely refer to the number in the global space to get
+		 * an IRQ out of it.
+		 */
+		.matches = {
+			DMI_EXACT_MATCH(DMI_BOARD_NAME, "GalileoGen2"),
+		},
+	},
+	{}
+};
+
+#ifdef CONFIG_ACPI
+static int pca953x_acpi_get_pin(struct acpi_resource *ares, void *data)
+{
+	struct acpi_resource_gpio *agpio;
+	int *pin = data;
+
+	if (acpi_gpio_get_irq_resource(ares, &agpio))
+		*pin = agpio->pin_table[0];
+	return 1;
+}
+
+static int pca953x_acpi_find_pin(struct device *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	int pin = -ENOENT, ret;
+	LIST_HEAD(r);
+
+	ret = acpi_dev_get_resources(adev, &r, pca953x_acpi_get_pin, &pin);
+	acpi_dev_free_resource_list(&r);
+	if (ret < 0)
+		return ret;
+
+	return pin;
+}
+#else
+static inline int pca953x_acpi_find_pin(struct device *dev) { return -ENXIO; }
+#endif
+
+static int pca953x_acpi_get_irq(struct device *dev)
+{
+	int pin, ret;
+
+	pin = pca953x_acpi_find_pin(dev);
+	if (pin < 0)
+		return pin;
+
+	dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin);
+
+	if (!gpio_is_valid(pin))
+		return -EINVAL;
+
+	ret = gpio_request(pin, "pca953x interrupt");
+	if (ret)
+		return ret;
+
+	ret = gpio_to_irq(pin);
+
+	/* When pin is used as an IRQ, no need to keep it requested */
+	gpio_free(pin);
+
+	return ret;
+}
+#endif
+
 static const struct acpi_device_id pca953x_acpi_ids[] = {
 	{ "INT3491", 16 | PCA953X_TYPE | PCA_LATCH_INT, },
 	{ }
@@ -307,8 +385,23 @@ static const struct regmap_config pca953x_i2c_regmap = {
 	.volatile_reg = pca953x_volatile_register,
 
 	.cache_type = REGCACHE_RBTREE,
-	/* REVISIT: should be 0x7f but some 24 bit chips use REG_ADDR_AI */
-	.max_register = 0xff,
+	.max_register = 0x7f,
+};
+
+static const struct regmap_config pca953x_ai_i2c_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.read_flag_mask = REG_ADDR_AI,
+	.write_flag_mask = REG_ADDR_AI,
+
+	.readable_reg = pca953x_readable_register,
+	.writeable_reg = pca953x_writeable_register,
+	.volatile_reg = pca953x_volatile_register,
+
+	.disable_locking = true,
+	.cache_type = REGCACHE_RBTREE,
+	.max_register = 0x7f,
 };
 
 static u8 pca953x_recalc_addr(struct pca953x_chip *chip, int reg, int off,
@@ -319,18 +412,6 @@ static u8 pca953x_recalc_addr(struct pca953x_chip *chip, int reg, int off,
 	int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
 	u8 regaddr = pinctrl | addr | (off / BANK_SZ);
 
-	/* Single byte read doesn't need AI bit set. */
-	if (!addrinc)
-		return regaddr;
-
-	/* Chips with 24 and more GPIOs always support Auto Increment */
-	if (write && NBANK(chip) > 2)
-		regaddr |= REG_ADDR_AI;
-
-	/* PCA9575 needs address-increment on multi-byte writes */
-	if (PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE)
-		regaddr |= REG_ADDR_AI;
-
 	return regaddr;
 }
 
@@ -771,6 +852,12 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
 	u8 reg_direction[MAX_BANK];
 	int ret, i;
 
+	if (dmi_first_match(pca953x_dmi_acpi_irq_info)) {
+		ret = pca953x_acpi_get_irq(&client->dev);
+		if (ret > 0)
+			client->irq = ret;
+	}
+
 	if (!client->irq)
 		return 0;
 
@@ -898,6 +985,7 @@ static int pca953x_probe(struct i2c_client *client,
 	int ret;
 	u32 invert = 0;
 	struct regulator *reg;
+	const struct regmap_config *regmap_config;
 
 	chip = devm_kzalloc(&client->dev,
 			sizeof(struct pca953x_chip), GFP_KERNEL);
@@ -965,7 +1053,17 @@ static int pca953x_probe(struct i2c_client *client,
 
 	i2c_set_clientdata(client, chip);
 
-	chip->regmap = devm_regmap_init_i2c(client, &pca953x_i2c_regmap);
+	pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);
+
+	if (NBANK(chip) > 2 || PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE) {
+		dev_info(&client->dev, "using AI\n");
+		regmap_config = &pca953x_ai_i2c_regmap;
+	} else {
+		dev_info(&client->dev, "using no AI\n");
+		regmap_config = &pca953x_i2c_regmap;
+	}
+
+	chip->regmap = devm_regmap_init_i2c(client, regmap_config);
 	if (IS_ERR(chip->regmap)) {
 		ret = PTR_ERR(chip->regmap);
 		goto err_exit;
@@ -1000,7 +1098,6 @@ static int pca953x_probe(struct i2c_client *client,
 	/* initialize cached registers from their original values.
 	 * we can't share this chip with another i2c master.
 	 */
-	pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);
 
 	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE) {
 		chip->regs = &pca953x_regs;