[PATCH v5 6/7] pinctrl: s32cc: add driver for GPIO functionality

[Andrei Stefanescu <andrei.stefanescu@xxxxxxxxxxx>]

Add basic GPIO functionality (request, free, get, set) for the existing
pinctrl SIUL2 driver since the hardware for pinctrl&GPIO is tightly
coupled.

Also, remove pinmux_ops which are no longer needed.

Signed-off-by: Andrei Stefanescu <andrei.stefanescu@xxxxxxxxxxx>
---
 drivers/pinctrl/nxp/pinctrl-s32cc.c | 410 +++++++++++++++++++++++-----
 1 file changed, 348 insertions(+), 62 deletions(-)

diff --git a/drivers/pinctrl/nxp/pinctrl-s32cc.c b/drivers/pinctrl/nxp/pinctrl-s32cc.c
index 10bff48852b9..1d4437df29a2 100644
--- a/drivers/pinctrl/nxp/pinctrl-s32cc.c
+++ b/drivers/pinctrl/nxp/pinctrl-s32cc.c
@@ -40,6 +40,14 @@
 #define S32_MSCR_ODE		BIT(20)
 #define S32_MSCR_OBE		BIT(21)
 
+/* PGPDOs are 16bit registers that come in big endian
+ * order if they are grouped in pairs of two.
+ *
+ * For example, the order is PGPDO1, PGPDO0, PGPDO3, PGPDO2...
+ */
+#define S32_PGPD(N)		(((N) ^ 1) * 2)
+#define S32_PGPD_SIZE		16
+
 enum s32_write_type {
 	S32_PINCONF_UPDATE_ONLY,
 	S32_PINCONF_OVERWRITE,
@@ -84,6 +92,7 @@ struct s32_pinctrl_context {
  * struct s32_pinctrl - private driver data
  * @dev: a pointer back to containing device
  * @pctl: a pointer to the pinctrl device structure
+ * @gc: a pointer to the gpio_chip
  * @regions: reserved memory regions with start/end pin
  * @info: structure containing information about the pin
  * @gpio_configs: Saved configurations for GPIO pins
@@ -93,6 +102,7 @@ struct s32_pinctrl_context {
 struct s32_pinctrl {
 	struct device *dev;
 	struct pinctrl_dev *pctl;
+	struct gpio_chip gc;
 	struct s32_pinctrl_mem_region *regions;
 	struct s32_pinctrl_soc_info *info;
 	struct list_head gpio_configs;
@@ -366,66 +376,6 @@ static int s32_pmx_get_groups(struct pinctrl_dev *pctldev,
 	return 0;
 }
 
-static int s32_pmx_gpio_request_enable(struct pinctrl_dev *pctldev,
-				       struct pinctrl_gpio_range *range,
-				       unsigned int offset)
-{
-	struct s32_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
-	struct gpio_pin_config *gpio_pin;
-	unsigned int config;
-	unsigned long flags;
-	int ret;
-
-	ret = s32_regmap_read(pctldev, offset, &config);
-	if (ret)
-		return ret;
-
-	/* Save current configuration */
-	gpio_pin = kmalloc(sizeof(*gpio_pin), GFP_KERNEL);
-	if (!gpio_pin)
-		return -ENOMEM;
-
-	gpio_pin->pin_id = offset;
-	gpio_pin->config = config;
-
-	spin_lock_irqsave(&ipctl->gpio_configs_lock, flags);
-	list_add(&gpio_pin->list, &ipctl->gpio_configs);
-	spin_unlock_irqrestore(&ipctl->gpio_configs_lock, flags);
-
-	/* GPIO pin means SSS = 0 */
-	config &= ~S32_MSCR_SSS_MASK;
-
-	return s32_regmap_write(pctldev, offset, config);
-}
-
-static void s32_pmx_gpio_disable_free(struct pinctrl_dev *pctldev,
-				      struct pinctrl_gpio_range *range,
-				      unsigned int offset)
-{
-	struct s32_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
-	struct gpio_pin_config *gpio_pin, *tmp;
-	unsigned long flags;
-	int ret;
-
-	spin_lock_irqsave(&ipctl->gpio_configs_lock, flags);
-
-	list_for_each_entry_safe(gpio_pin, tmp, &ipctl->gpio_configs, list) {
-		if (gpio_pin->pin_id == offset) {
-			ret = s32_regmap_write(pctldev, gpio_pin->pin_id,
-						 gpio_pin->config);
-			if (ret != 0)
-				goto unlock;
-
-			list_del(&gpio_pin->list);
-			kfree(gpio_pin);
-			break;
-		}
-	}
-
-unlock:
-	spin_unlock_irqrestore(&ipctl->gpio_configs_lock, flags);
-}
-
 static int s32_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
 				      struct pinctrl_gpio_range *range,
 				      unsigned int offset,
@@ -449,8 +399,6 @@ static const struct pinmux_ops s32_pmx_ops = {
 	.get_function_name = s32_pmx_get_func_name,
 	.get_function_groups = s32_pmx_get_groups,
 	.set_mux = s32_pmx_set,
-	.gpio_request_enable = s32_pmx_gpio_request_enable,
-	.gpio_disable_free = s32_pmx_gpio_disable_free,
 	.gpio_set_direction = s32_pmx_gpio_set_direction,
 };
 
@@ -669,6 +617,315 @@ static const struct pinconf_ops s32_pinconf_ops = {
 	.pin_config_group_dbg_show = s32_pinconf_group_dbg_show,
 };
 
+static struct s32_pinctrl *to_s32_pinctrl(struct gpio_chip *chip)
+{
+	return container_of(chip, struct s32_pinctrl, gc);
+}
+
+static struct regmap *s32_gpio_get_pgpd_regmap(struct gpio_chip *chip,
+					       unsigned int pin,
+					       bool output)
+{
+	struct s32_pinctrl *ipctl = to_s32_pinctrl(chip);
+	struct nxp_siul2_mfd *mfd;
+	u32 base, num;
+	int i;
+
+	mfd = dev_get_drvdata(ipctl->dev->parent);
+
+	for (i = 0; i < mfd->num_siul2; i++) {
+		base = mfd->siul2[i].gpio_base;
+		num = mfd->siul2[i].gpio_num;
+
+		if (pin >= base && pin < base + num)
+			return output ? mfd->siul2[i].regmaps[SIUL2_PGPDO] :
+					mfd->siul2[i].regmaps[SIUL2_PGPDI];
+	}
+
+	return NULL;
+}
+
+static int s32_gpio_request(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct s32_pinctrl *ipctl = to_s32_pinctrl(gc);
+	struct pinctrl_dev *pctldev = ipctl->pctl;
+	struct gpio_pin_config *gpio_pin;
+	unsigned int config;
+	unsigned long flags;
+	int ret;
+
+	ret = s32_regmap_read(pctldev, gpio, &config);
+	if (ret)
+		return ret;
+
+	/* Save current configuration */
+	gpio_pin = kmalloc(sizeof(*gpio_pin), GFP_KERNEL);
+	if (!gpio_pin)
+		return -ENOMEM;
+
+	gpio_pin->pin_id = gpio;
+	gpio_pin->config = config;
+
+	spin_lock_irqsave(&ipctl->gpio_configs_lock, flags);
+	list_add(&gpio_pin->list, &ipctl->gpio_configs);
+	spin_unlock_irqrestore(&ipctl->gpio_configs_lock, flags);
+
+	/* GPIO pin means SSS = 0 */
+	config &= ~S32_MSCR_SSS_MASK;
+
+	return s32_regmap_write(pctldev, gpio, config);
+}
+
+static void s32_gpio_free(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct s32_pinctrl *ipctl = to_s32_pinctrl(gc);
+	struct pinctrl_dev *pctldev = ipctl->pctl;
+	struct gpio_pin_config *gpio_pin, *tmp;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&ipctl->gpio_configs_lock, flags);
+
+	list_for_each_entry_safe(gpio_pin, tmp, &ipctl->gpio_configs, list) {
+		if (gpio_pin->pin_id == gpio) {
+			ret = s32_regmap_write(pctldev, gpio_pin->pin_id,
+					       gpio_pin->config);
+			if (ret != 0)
+				goto unlock;
+
+			list_del(&gpio_pin->list);
+			kfree(gpio_pin);
+			break;
+		}
+	}
+
+unlock:
+	spin_unlock_irqrestore(&ipctl->gpio_configs_lock, flags);
+}
+
+static int s32_gpio_get_dir(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct s32_pinctrl *ipctl = to_s32_pinctrl(chip);
+	unsigned int reg_value;
+	int ret;
+
+	ret = s32_regmap_read(ipctl->pctl, gpio, &reg_value);
+	if (ret)
+		return ret;
+
+	if (!(reg_value & S32_MSCR_IBE))
+		return -EINVAL;
+
+	return reg_value & S32_MSCR_OBE ? GPIO_LINE_DIRECTION_OUT :
+					  GPIO_LINE_DIRECTION_IN;
+}
+
+static unsigned int s32_pin2pad(unsigned int pin)
+{
+	return pin / S32_PGPD_SIZE;
+}
+
+static u16 s32_pin2mask(unsigned int pin)
+{
+	/**
+	 * From Reference manual :
+	 * PGPDOx[PPDOy] = GPDO(x × 16) + (15 - y)[PDO_(x × 16) + (15 - y)]
+	 */
+	return BIT(S32_PGPD_SIZE - 1 - pin % S32_PGPD_SIZE);
+}
+
+static struct regmap *s32_gpio_get_regmap_offset_mask(struct gpio_chip *chip,
+						      unsigned int gpio,
+						      unsigned int *reg_offset,
+						      u16 *mask,
+						      bool output)
+{
+	struct regmap *regmap;
+	unsigned int pad;
+
+	regmap = s32_gpio_get_pgpd_regmap(chip, gpio, output);
+	if (!regmap)
+		return NULL;
+
+	*mask = s32_pin2mask(gpio);
+	pad = s32_pin2pad(gpio);
+
+	*reg_offset = S32_PGPD(pad);
+
+	return regmap;
+}
+
+static void s32_gpio_set_val(struct gpio_chip *chip, unsigned int gpio,
+			     int value)
+{
+	unsigned int reg_offset;
+	struct regmap *regmap;
+	u16 mask;
+
+	regmap = s32_gpio_get_regmap_offset_mask(chip, gpio, &reg_offset,
+						 &mask, true);
+	if (!regmap)
+		return;
+
+	value = value ? mask : 0;
+
+	regmap_update_bits(regmap, reg_offset, mask, value);
+}
+
+static void s32_gpio_set(struct gpio_chip *chip, unsigned int gpio,
+			 int value)
+{
+	if (s32_gpio_get_dir(chip, gpio) != GPIO_LINE_DIRECTION_OUT)
+		return;
+
+	s32_gpio_set_val(chip, gpio, value);
+}
+
+static int s32_gpio_get(struct gpio_chip *chip, unsigned int gpio)
+{
+	unsigned int reg_offset, value;
+	struct regmap *regmap;
+	u16 mask;
+	int ret;
+
+	if (s32_gpio_get_dir(chip, gpio) != GPIO_LINE_DIRECTION_IN)
+		return -EINVAL;
+
+	regmap = s32_gpio_get_regmap_offset_mask(chip, gpio, &reg_offset,
+						 &mask, false);
+	if (!regmap)
+		return -EINVAL;
+
+	ret = regmap_read(regmap, reg_offset, &value);
+	if (ret)
+		return ret;
+
+	return !!(value & mask);
+}
+
+static int s32_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
+			    int val)
+{
+	struct s32_pinctrl *ipctl = to_s32_pinctrl(chip);
+
+	s32_gpio_set_val(chip, gpio, val);
+
+	return s32_pmx_gpio_set_direction(ipctl->pctl, NULL, gpio, false);
+}
+
+static int s32_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
+{
+	struct s32_pinctrl *ipctl = to_s32_pinctrl(chip);
+
+	return s32_pmx_gpio_set_direction(ipctl->pctl, NULL, gpio, true);
+}
+
+static int s32_gpio_gen_names(struct device *dev, unsigned int cnt, char **names,
+			      char *ch_index, unsigned int *num_index)
+{
+	unsigned int i;
+
+	for (i = 0; i < cnt; i++) {
+		if (i != 0 && !(*num_index % 16))
+			(*ch_index)++;
+
+		names[i] = devm_kasprintf(dev, GFP_KERNEL, "P%c_%02d",
+					  *ch_index, 0xFU & (*num_index)++);
+		if (!names[i])
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int s32_gpio_remove_reserved_names(struct device *dev,
+					  struct s32_pinctrl *ipctl,
+					  char **names)
+{
+	struct device_node *np = dev->of_node;
+	int num_ranges, i, j, ret;
+	u32 base_gpio, num_gpio;
+
+	/* Parse the gpio-reserved-ranges to know which GPIOs to exclude. */
+
+	num_ranges = of_property_count_u32_elems(dev->of_node,
+						 "gpio-reserved-ranges");
+
+	/* The "gpio-reserved-ranges" is optional. */
+	if (num_ranges < 0)
+		return 0;
+	num_ranges /= 2;
+
+	for (i = 0; i < num_ranges; i++) {
+		ret = of_property_read_u32_index(np, "gpio-reserved-ranges",
+						 i * 2, &base_gpio);
+		if (ret) {
+			dev_err(dev, "Could not parse the start GPIO: %d\n",
+				ret);
+			return ret;
+		}
+
+		ret = of_property_read_u32_index(np, "gpio-reserved-ranges",
+						 i * 2 + 1, &num_gpio);
+		if (ret) {
+			dev_err(dev, "Could not parse num. GPIOs: %d\n", ret);
+			return ret;
+		}
+
+		if (base_gpio + num_gpio > ipctl->gc.ngpio) {
+			dev_err(dev, "Reserved GPIOs outside of GPIO range\n");
+			return -EINVAL;
+		}
+
+		/* Remove names set for reserved GPIOs. */
+		for (j = base_gpio; j < base_gpio + num_gpio; j++) {
+			devm_kfree(dev, names[j]);
+			names[j] = NULL;
+		}
+	}
+
+	return 0;
+}
+
+static int s32_gpio_populate_names(struct device *dev,
+				   struct s32_pinctrl *ipctl)
+{
+	struct nxp_siul2_mfd *mfd = dev_get_drvdata(ipctl->dev->parent);
+	unsigned int num_index = 0;
+	char ch_index = 'A';
+	char **names;
+	int i, ret;
+
+	names = devm_kcalloc(dev, ipctl->gc.ngpio, sizeof(*names),
+			     GFP_KERNEL);
+	if (!names)
+		return -ENOMEM;
+
+	for (i = 0; i < mfd->num_siul2; i++) {
+		if (mfd->siul2[i].gpio_base % 16 == 0)
+			num_index = 0;
+
+		ret = s32_gpio_gen_names(dev, mfd->siul2[i].gpio_num,
+					 names + mfd->siul2[i].gpio_base,
+					 &ch_index, &num_index);
+		if (ret) {
+			dev_err(dev, "Could not set names for SIUL2_%d GPIOs\n",
+				i);
+			return ret;
+		}
+
+		ch_index++;
+	}
+
+	ret = s32_gpio_remove_reserved_names(dev, ipctl, names);
+	if (ret)
+		return ret;
+
+	ipctl->gc.names = (const char *const *)names;
+
+	return 0;
+}
+
 #ifdef CONFIG_PM_SLEEP
 static bool s32_pinctrl_should_save(struct s32_pinctrl *ipctl,
 				    unsigned int pin)
@@ -899,12 +1156,14 @@ static int s32_pinctrl_probe_dt(struct platform_device *pdev,
 int s32_pinctrl_probe(struct platform_device *pdev,
 		      const struct s32_pinctrl_soc_data *soc_data)
 {
+	struct nxp_siul2_mfd *mfd = dev_get_drvdata(pdev->dev.parent);
 #ifdef CONFIG_PM_SLEEP
 	struct s32_pinctrl_context *saved_context;
 #endif
 	struct pinctrl_desc *s32_pinctrl_desc;
 	struct s32_pinctrl_soc_info *info;
 	struct s32_pinctrl *ipctl;
+	struct gpio_chip *gc;
 	int ret;
 
 	if (!soc_data || !soc_data->pins || !soc_data->npins) {
@@ -973,5 +1232,32 @@ int s32_pinctrl_probe(struct platform_device *pdev,
 
 	dev_info(&pdev->dev, "initialized s32 pinctrl driver\n");
 
+	gc = &ipctl->gc;
+	gc->parent = &pdev->dev;
+	gc->label = dev_name(&pdev->dev);
+	gc->base = -1;
+	/* In some cases, there is a gap between the SIUL GPIOs. */
+	gc->ngpio = mfd->siul2[mfd->num_siul2 - 1].gpio_base +
+		    mfd->siul2[mfd->num_siul2 - 1].gpio_num;
+	ret = s32_gpio_populate_names(&pdev->dev, ipctl);
+	if (ret)
+		return ret;
+
+	gc->set = s32_gpio_set;
+	gc->get = s32_gpio_get;
+	gc->set_config = gpiochip_generic_config;
+	gc->request = s32_gpio_request;
+	gc->free = s32_gpio_free;
+	gc->direction_output = s32_gpio_dir_out;
+	gc->direction_input = s32_gpio_dir_in;
+	gc->get_direction = s32_gpio_get_dir;
+
+	ret = devm_gpiochip_add_data(&pdev->dev, gc, ipctl);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "unable to add gpiochip\n");
+
+	dev_info(&pdev->dev, "initialized s32 GPIO driver\n");
+
 	return 0;
 }
-- 
2.45.2