Merge branch 'gpio-reserved-ranges' into devel

Author: linusw

Documentation/devicetree/bindings/gpio/gpio.txt

@@ -151,9 +151,9 @@ in a lot of designs, some using all 32 bits, some using 18 and some using
 first 18 GPIOs, at local offset 0 .. 17, are in use.
 
 If these GPIOs do not happen to be the first N GPIOs at offset 0...N-1, an
-additional bitmask is needed to specify which GPIOs are actually in use,
-and which are dummies. The bindings for this case has not yet been
-specified, but should be specified if/when such hardware appears.
+additional set of tuples is needed to specify which GPIOs are unusable, with
+the gpio-reserved-ranges binding. This property indicates the start and size
+of the GPIOs that can't be used.
 
 Optionally, a GPIO controller may have a "gpio-line-names" property. This is
 an array of strings defining the names of the GPIO lines going out of the
@@ -178,6 +178,7 @@ gpio-controller@00000000 {
 	gpio-controller;
 	#gpio-cells = <2>;
 	ngpios = <18>;
+	gpio-reserved-ranges = <0 4>, <12 2>;
 	gpio-line-names = "MMC-CD", "MMC-WP", "VDD eth", "RST eth", "LED R",
 		"LED G", "LED B", "Col A", "Col B", "Col C", "Col D",
 		"Row A", "Row B", "Row C", "Row D", "NMI button",

drivers/gpio/gpiolib-of.c

@@ -511,6 +511,28 @@ void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
 }
 EXPORT_SYMBOL(of_mm_gpiochip_remove);
 
+static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
+{
+	int len, i;
+	u32 start, count;
+	struct device_node *np = chip->of_node;
+
+	len = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
+	if (len < 0 || len % 2 != 0)
+		return;
+
+	for (i = 0; i < len; i += 2) {
+		of_property_read_u32_index(np, "gpio-reserved-ranges",
+					   i, &start);
+		of_property_read_u32_index(np, "gpio-reserved-ranges",
+					   i + 1, &count);
+		if (start >= chip->ngpio || start + count >= chip->ngpio)
+			continue;
+
+		bitmap_clear(chip->valid_mask, start, count);
+	}
+};
+
 #ifdef CONFIG_PINCTRL
 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
 {
@@ -615,6 +637,8 @@ int of_gpiochip_add(struct gpio_chip *chip)
 	if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
 		return -EINVAL;
 
+	of_gpiochip_init_valid_mask(chip);
+
 	status = of_gpiochip_add_pin_range(chip);
 	if (status)
 		return status;

drivers/gpio/gpiolib.c

@@ -337,6 +337,57 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc)
 	return 0;
 }
 
+static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
+{
+	unsigned long *p;
+
+	p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return NULL;
+
+	/* Assume by default all GPIOs are valid */
+	bitmap_fill(p, chip->ngpio);
+
+	return p;
+}
+
+static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip)
+{
+#ifdef CONFIG_OF_GPIO
+	int size;
+	struct device_node *np = gpiochip->of_node;
+
+	size = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
+	if (size > 0 && size % 2 == 0)
+		gpiochip->need_valid_mask = true;
+#endif
+
+	if (!gpiochip->need_valid_mask)
+		return 0;
+
+	gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip);
+	if (!gpiochip->valid_mask)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
+{
+	kfree(gpiochip->valid_mask);
+	gpiochip->valid_mask = NULL;
+}
+
+bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
+				unsigned int offset)
+{
+	/* No mask means all valid */
+	if (likely(!gpiochip->valid_mask))
+		return true;
+	return test_bit(offset, gpiochip->valid_mask);
+}
+EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
+
 /*
  * GPIO line handle management
  */
@@ -1261,6 +1312,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 	if (status)
 		goto err_remove_from_list;
 
+	status = gpiochip_init_valid_mask(chip);
+	if (status)
+		goto err_remove_irqchip_mask;
+
 	status = gpiochip_add_irqchip(chip, lock_key, request_key);
 	if (status)
 		goto err_remove_chip;
@@ -1290,6 +1345,8 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 	acpi_gpiochip_remove(chip);
 	gpiochip_free_hogs(chip);
 	of_gpiochip_remove(chip);
+	gpiochip_free_valid_mask(chip);
+err_remove_irqchip_mask:
 	gpiochip_irqchip_free_valid_mask(chip);
 err_remove_from_list:
 	spin_lock_irqsave(&gpio_lock, flags);
@@ -1346,6 +1403,7 @@ void gpiochip_remove(struct gpio_chip *chip)
 	acpi_gpiochip_remove(chip);
 	gpiochip_remove_pin_ranges(chip);
 	of_gpiochip_remove(chip);
+	gpiochip_free_valid_mask(chip);
 	/*
 	 * We accept no more calls into the driver from this point, so
 	 * NULL the driver data pointer
@@ -1506,14 +1564,10 @@ static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
 	if (!gpiochip->irq.need_valid_mask)
 		return 0;
 
-	gpiochip->irq.valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
-					   sizeof(long), GFP_KERNEL);
+	gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip);
 	if (!gpiochip->irq.valid_mask)
 		return -ENOMEM;
 
-	/* Assume by default all GPIOs are valid */
-	bitmap_fill(gpiochip->irq.valid_mask, gpiochip->ngpio);
-
 	return 0;
 }
 
@@ -1526,6 +1580,8 @@ static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
 				unsigned int offset)
 {
+	if (!gpiochip_line_is_valid(gpiochip, offset))
+		return false;
 	/* No mask means all valid */
 	if (likely(!gpiochip->irq.valid_mask))
 		return true;

drivers/pinctrl/qcom/pinctrl-msm.c

@@ -105,6 +105,14 @@ static const struct pinctrl_ops msm_pinctrl_ops = {
 	.dt_free_map		= pinctrl_utils_free_map,
 };
 
+static int msm_pinmux_request(struct pinctrl_dev *pctldev, unsigned offset)
+{
+	struct msm_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
+	struct gpio_chip *chip = &pctrl->chip;
+
+	return gpiochip_line_is_valid(chip, offset) ? 0 : -EINVAL;
+}
+
 static int msm_get_functions_count(struct pinctrl_dev *pctldev)
 {
 	struct msm_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
@@ -166,6 +174,7 @@ static int msm_pinmux_set_mux(struct pinctrl_dev *pctldev,
 }
 
 static const struct pinmux_ops msm_pinmux_ops = {
+	.request		= msm_pinmux_request,
 	.get_functions_count	= msm_get_functions_count,
 	.get_function_name	= msm_get_function_name,
 	.get_function_groups	= msm_get_function_groups,
@@ -506,6 +515,9 @@ static void msm_gpio_dbg_show_one(struct seq_file *s,
 		"pull up"
 	};
 
+	if (!gpiochip_line_is_valid(chip, offset))
+		return;
+
 	g = &pctrl->soc->groups[offset];
 	ctl_reg = readl(pctrl->regs + g->ctl_reg);
 
@@ -517,17 +529,16 @@ static void msm_gpio_dbg_show_one(struct seq_file *s,
 	seq_printf(s, " %-8s: %-3s %d", g->name, is_out ? "out" : "in", func);
 	seq_printf(s, " %dmA", msm_regval_to_drive(drive));
 	seq_printf(s, " %s", pulls[pull]);
+	seq_puts(s, "\n");
 }
 
 static void msm_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 {
 	unsigned gpio = chip->base;
 	unsigned i;
 
-	for (i = 0; i < chip->ngpio; i++, gpio++) {
+	for (i = 0; i < chip->ngpio; i++, gpio++)
 		msm_gpio_dbg_show_one(s, NULL, chip, i, gpio);
-		seq_puts(s, "\n");
-	}
 }
 
 #else
@@ -808,6 +819,46 @@ static void msm_gpio_irq_handler(struct irq_desc *desc)
 	chained_irq_exit(chip, desc);
 }
 
+static int msm_gpio_init_valid_mask(struct gpio_chip *chip,
+				    struct msm_pinctrl *pctrl)
+{
+	int ret;
+	unsigned int len, i;
+	unsigned int max_gpios = pctrl->soc->ngpios;
+	u16 *tmp;
+
+	/* The number of GPIOs in the ACPI tables */
+	len = ret = device_property_read_u16_array(pctrl->dev, "gpios", NULL, 0);
+	if (ret < 0)
+		return 0;
+
+	if (ret > max_gpios)
+		return -EINVAL;
+
+	tmp = kmalloc_array(len, sizeof(*tmp), GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+
+	ret = device_property_read_u16_array(pctrl->dev, "gpios", tmp, len);
+	if (ret < 0) {
+		dev_err(pctrl->dev, "could not read list of GPIOs\n");
+		goto out;
+	}
+
+	bitmap_zero(chip->valid_mask, max_gpios);
+	for (i = 0; i < len; i++)
+		set_bit(tmp[i], chip->valid_mask);
+
+out:
+	kfree(tmp);
+	return ret;
+}
+
+static bool msm_gpio_needs_valid_mask(struct msm_pinctrl *pctrl)
+{
+	return device_property_read_u16_array(pctrl->dev, "gpios", NULL, 0) > 0;
+}
+
 static int msm_gpio_init(struct msm_pinctrl *pctrl)
 {
 	struct gpio_chip *chip;
@@ -824,13 +875,21 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl)
 	chip->parent = pctrl->dev;
 	chip->owner = THIS_MODULE;
 	chip->of_node = pctrl->dev->of_node;
+	chip->need_valid_mask = msm_gpio_needs_valid_mask(pctrl);
 
 	ret = gpiochip_add_data(&pctrl->chip, pctrl);
 	if (ret) {
 		dev_err(pctrl->dev, "Failed register gpiochip\n");
 		return ret;
 	}
 
+	ret = msm_gpio_init_valid_mask(chip, pctrl);
+	if (ret) {
+		dev_err(pctrl->dev, "Failed to setup irq valid bits\n");
+		gpiochip_remove(&pctrl->chip);
+		return ret;
+	}
+
 	ret = gpiochip_add_pin_range(&pctrl->chip, dev_name(pctrl->dev), 0, 0, chip->ngpio);
 	if (ret) {
 		dev_err(pctrl->dev, "Failed to add pin range\n");

include/linux/gpio/driver.h

@@ -288,6 +288,21 @@ struct gpio_chip {
 	struct gpio_irq_chip irq;
 #endif
 
+	/**
+	 * @need_valid_mask:
+	 *
+	 * If set core allocates @valid_mask with all bits set to one.
+	 */
+	bool need_valid_mask;
+
+	/**
+	 * @valid_mask:
+	 *
+	 * If not %NULL holds bitmask of GPIOs which are valid to be used
+	 * from the chip.
+	 */
+	unsigned long *valid_mask;
+
 #if defined(CONFIG_OF_GPIO)
 	/*
 	 * If CONFIG_OF is enabled, then all GPIO controllers described in the
@@ -384,6 +399,7 @@ bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
 
 /* Sleep persistence inquiry for drivers */
 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset);
+bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset);
 
 /* get driver data */
 void *gpiochip_get_data(struct gpio_chip *chip);