sh: pfc: pinctrl legacy function support.

This maps out all of the function types to pinctrl function groups.
Presently this is restricted to one pin per function to maintain
compatability with legacy behaviour. This will be extended as groups
are introduced and exiting users migrated.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/sh/pfc/pinctrl.c

@@ -14,6 +14,7 @@
 #include <linux/sh_pfc.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/spinlock.h>
 #include <linux/platform_device.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/pinctrl/pinctrl.h>
@@ -25,8 +26,13 @@ struct sh_pfc_pinctrl {
 	struct pinctrl_dev *pctl;
 	struct sh_pfc *pfc;
 
+	struct pinmux_gpio **functions;
+	unsigned int nr_functions;
+
 	struct pinctrl_pin_desc *pads;
 	unsigned int nr_pads;
+
+	spinlock_t lock;
 };
 
 static struct sh_pfc_pinctrl *sh_pfc_pmx;
@@ -57,14 +63,30 @@ static struct pinctrl_ops sh_pfc_pinctrl_ops = {
 	.get_group_pins		= sh_pfc_get_group_pins,
 };
 
+static int sh_pfc_get_functions_count(struct pinctrl_dev *pctldev)
+{
+	struct sh_pfc_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pmx->nr_functions;
+}
+
+static const char *sh_pfc_get_function_name(struct pinctrl_dev *pctldev,
+					    unsigned selector)
+{
+	struct sh_pfc_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pmx->functions[selector]->name;
+}
 
-/*
- * No function support yet
- */
 static int sh_pfc_get_function_groups(struct pinctrl_dev *pctldev, unsigned func,
 				      const char * const **groups,
 				      unsigned * const num_groups)
 {
+	struct sh_pfc_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	*groups = &pmx->functions[func]->name;
+	*num_groups = 1;
+
 	return 0;
 }
 
@@ -79,41 +101,50 @@ static void sh_pfc_noop_disable(struct pinctrl_dev *pctldev, unsigned func,
 {
 }
 
+static inline int sh_pfc_config_function(struct sh_pfc *pfc, unsigned offset)
+{
+	if (sh_pfc_config_gpio(pfc, offset,
+			       PINMUX_TYPE_FUNCTION,
+			       GPIO_CFG_DRYRUN) != 0)
+		return -EINVAL;
+
+	if (sh_pfc_config_gpio(pfc, offset,
+			       PINMUX_TYPE_FUNCTION,
+			       GPIO_CFG_REQ) != 0)
+		return -EINVAL;
+
+	return 0;
+}
+
 static int sh_pfc_gpio_request_enable(struct pinctrl_dev *pctldev,
 				      struct pinctrl_gpio_range *range,
 				      unsigned offset)
 {
 	struct sh_pfc_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
 	struct sh_pfc *pfc = pmx->pfc;
-	struct pinmux_data_reg *dummy;
 	unsigned long flags;
-	int i, ret, pinmux_type;
-
-	ret = -EINVAL;
+	int ret, pinmux_type;
 
 	spin_lock_irqsave(&pfc->lock, flags);
 
-	if ((pfc->gpios[offset].flags & PINMUX_FLAG_TYPE) != PINMUX_TYPE_NONE)
-		goto err;
-
-	/* setup pin function here if no data is associated with pin */
-	if (sh_pfc_get_data_reg(pfc, offset, &dummy, &i) != 0) {
-		pinmux_type = PINMUX_TYPE_FUNCTION;
-
-		if (sh_pfc_config_gpio(pfc, offset,
-				       pinmux_type,
-				       GPIO_CFG_DRYRUN) != 0)
-			goto err;
+	pinmux_type = pfc->gpios[offset].flags & PINMUX_FLAG_TYPE;
 
-		if (sh_pfc_config_gpio(pfc, offset,
-				       pinmux_type,
-				       GPIO_CFG_REQ) != 0)
+	switch (pinmux_type) {
+	case PINMUX_TYPE_FUNCTION:
+		pr_notice_once("Use of GPIO API for function requests is "
+			       "deprecated, convert to pinctrl\n");
+		/* handle for now */
+		ret = sh_pfc_config_function(pfc, offset);
+		if (unlikely(ret < 0))
 			goto err;
-	} else
-		pinmux_type = PINMUX_TYPE_GPIO;
 
-	pfc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
-	pfc->gpios[offset].flags |= pinmux_type;
+		break;
+	case PINMUX_TYPE_GPIO:
+		break;
+	default:
+		pr_err("Unsupported mux type (%d), bailing...\n", pinmux_type);
+		return -ENOTSUPP;
+	}
 
 	ret = 0;
 
@@ -138,9 +169,6 @@ static void sh_pfc_gpio_disable_free(struct pinctrl_dev *pctldev,
 
 	sh_pfc_config_gpio(pfc, offset, pinmux_type, GPIO_CFG_FREE);
 
-	pfc->gpios[offset].flags &= ~PINMUX_FLAG_TYPE;
-	pfc->gpios[offset].flags |= PINMUX_TYPE_NONE;
-
 	spin_unlock_irqrestore(&pfc->lock, flags);
 }
 
@@ -195,8 +223,8 @@ err:
 }
 
 static struct pinmux_ops sh_pfc_pinmux_ops = {
-	.get_functions_count	= sh_pfc_get_noop_count,
-	.get_function_name	= sh_pfc_get_noop_name,
+	.get_functions_count	= sh_pfc_get_functions_count,
+	.get_function_name	= sh_pfc_get_function_name,
 	.get_function_groups	= sh_pfc_get_function_groups,
 	.enable			= sh_pfc_noop_enable,
 	.disable		= sh_pfc_noop_disable,
@@ -208,6 +236,13 @@ static struct pinmux_ops sh_pfc_pinmux_ops = {
 static int sh_pfc_pinconf_get(struct pinctrl_dev *pctldev, unsigned pin,
 			      unsigned long *config)
 {
+	enum pin_config_param param = (enum pin_config_param)(*config);
+
+	switch (param) {
+	default:
+		break;
+	}
+
 	return -ENOTSUPP;
 }
 
@@ -238,19 +273,44 @@ static struct pinctrl_desc sh_pfc_pinctrl_desc = {
 
 int sh_pfc_register_pinctrl(struct sh_pfc *pfc)
 {
-	sh_pfc_pmx = kmalloc(sizeof(struct sh_pfc_pinctrl), GFP_KERNEL);
+	sh_pfc_pmx = kzalloc(sizeof(struct sh_pfc_pinctrl), GFP_KERNEL);
 	if (unlikely(!sh_pfc_pmx))
 		return -ENOMEM;
 
+	spin_lock_init(&sh_pfc_pmx->lock);
+
 	sh_pfc_pmx->pfc = pfc;
 
 	return 0;
 }
 
+static inline void __devinit sh_pfc_map_one_gpio(struct sh_pfc *pfc,
+						 struct sh_pfc_pinctrl *pmx,
+						 struct pinmux_gpio *gpio,
+						 unsigned offset)
+{
+	struct pinmux_data_reg *dummy;
+	unsigned long flags;
+	int bit;
+
+	gpio->flags &= ~PINMUX_FLAG_TYPE;
+
+	if (sh_pfc_get_data_reg(pfc, offset, &dummy, &bit) == 0)
+		gpio->flags |= PINMUX_TYPE_GPIO;
+	else {
+		gpio->flags |= PINMUX_TYPE_FUNCTION;
+
+		spin_lock_irqsave(&pmx->lock, flags);
+		pmx->nr_functions++;
+		spin_unlock_irqrestore(&pmx->lock, flags);
+	}
+}
+
 /* pinmux ranges -> pinctrl pin descs */
 static int __devinit sh_pfc_map_gpios(struct sh_pfc *pfc,
 				      struct sh_pfc_pinctrl *pmx)
 {
+	unsigned long flags;
 	int i;
 
 	pmx->nr_pads = pfc->last_gpio - pfc->first_gpio + 1;
@@ -262,6 +322,8 @@ static int __devinit sh_pfc_map_gpios(struct sh_pfc *pfc,
 		return -ENOMEM;
 	}
 
+	spin_lock_irqsave(&pfc->lock, flags);
+
 	/*
 	 * We don't necessarily have a 1:1 mapping between pin and linux
 	 * GPIO number, as the latter maps to the associated enum_id.
@@ -274,14 +336,43 @@ static int __devinit sh_pfc_map_gpios(struct sh_pfc *pfc,
 
 		pin->number = pfc->first_gpio + i;
 		pin->name = gpio->name;
+
+		sh_pfc_map_one_gpio(pfc, pmx, gpio, i);
 	}
 
+	spin_unlock_irqrestore(&pfc->lock, flags);
+
 	sh_pfc_pinctrl_desc.pins = pmx->pads;
 	sh_pfc_pinctrl_desc.npins = pmx->nr_pads;
 
 	return 0;
 }
 
+static int __devinit sh_pfc_map_functions(struct sh_pfc *pfc,
+					  struct sh_pfc_pinctrl *pmx)
+{
+	unsigned long flags;
+	int i, fn;
+
+	pmx->functions = kzalloc(pmx->nr_functions * sizeof(void *),
+				 GFP_KERNEL);
+	if (unlikely(!pmx->functions))
+		return -ENOMEM;
+
+	spin_lock_irqsave(&pmx->lock, flags);
+
+	for (i = fn = 0; i < pmx->nr_pads; i++) {
+		struct pinmux_gpio *gpio = pfc->gpios + i;
+
+		if ((gpio->flags & PINMUX_FLAG_TYPE) == PINMUX_TYPE_FUNCTION)
+			pmx->functions[fn++] = gpio;
+	}
+
+	spin_unlock_irqrestore(&pmx->lock, flags);
+
+	return 0;
+}
+
 static int __devinit sh_pfc_pinctrl_probe(struct platform_device *pdev)
 {
 	struct sh_pfc *pfc;
@@ -296,11 +387,15 @@ static int __devinit sh_pfc_pinctrl_probe(struct platform_device *pdev)
 	if (unlikely(ret != 0))
 		return ret;
 
+	ret = sh_pfc_map_functions(pfc, sh_pfc_pmx);
+	if (unlikely(ret != 0))
+		goto free_pads;
+
 	sh_pfc_pmx->pctl = pinctrl_register(&sh_pfc_pinctrl_desc, &pdev->dev,
 					    sh_pfc_pmx);
 	if (IS_ERR(sh_pfc_pmx->pctl)) {
 		ret = PTR_ERR(sh_pfc_pmx->pctl);
-		goto out;
+		goto free_functions;
 	}
 
 	sh_pfc_gpio_range.npins = pfc->last_gpio - pfc->first_gpio + 1;
@@ -313,9 +408,12 @@ static int __devinit sh_pfc_pinctrl_probe(struct platform_device *pdev)
 
 	return 0;
 
-out:
+free_functions:
+	kfree(sh_pfc_pmx->functions);
+free_pads:
 	kfree(sh_pfc_pmx->pads);
 	kfree(sh_pfc_pmx);
+
 	return ret;
 }
 
@@ -328,6 +426,7 @@ static int __devexit sh_pfc_pinctrl_remove(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, NULL);
 
+	kfree(sh_pfc_pmx->functions);
 	kfree(sh_pfc_pmx->pads);
 	kfree(sh_pfc_pmx);