pinctrl: replace list_*() with get_*_count()

Most of the SoC drivers implement list_groups() and list_functions()
routines for pinctrl and pinmux. These routines continue returning
zero until the selector argument is greater than total count of
available groups or functions.

This patch replaces these list_*() routines with get_*_count()
routines, which returns the number of available selection for SoC
driver. pinctrl layer will use this value to check the range it can
choose.

This patch fixes all user drivers for this change. There are other
routines in user drivers, which have checks to check validity of
selector passed to them. It is also no more required and hence
removed.

Documentation updated as well.
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
[Folded in fix and fixed a minor merge artifact manually]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/pinctrl.txt

@@ -152,11 +152,9 @@ static const struct foo_group foo_groups[] = {
 };
 
 
-static int foo_list_groups(struct pinctrl_dev *pctldev, unsigned selector)
+static int foo_get_groups_count(struct pinctrl_dev *pctldev)
 {
-	if (selector >= ARRAY_SIZE(foo_groups))
-		return -EINVAL;
-	return 0;
+	return ARRAY_SIZE(foo_groups);
 }
 
 static const char *foo_get_group_name(struct pinctrl_dev *pctldev,
@@ -175,7 +173,7 @@ static int foo_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
 }
 
 static struct pinctrl_ops foo_pctrl_ops = {
-	.list_groups = foo_list_groups,
+	.get_groups_count = foo_get_groups_count,
 	.get_group_name = foo_get_group_name,
 	.get_group_pins = foo_get_group_pins,
 };
@@ -186,13 +184,12 @@ static struct pinctrl_desc foo_desc = {
        .pctlops = &foo_pctrl_ops,
 };
 
-The pin control subsystem will call the .list_groups() function repeatedly
-beginning on 0 until it returns non-zero to determine legal selectors, then
-it will call the other functions to retrieve the name and pins of the group.
-Maintaining the data structure of the groups is up to the driver, this is
-just a simple example - in practice you may need more entries in your group
-structure, for example specific register ranges associated with each group
-and so on.
+The pin control subsystem will call the .get_groups_count() function to
+determine total number of legal selectors, then it will call the other functions
+to retrieve the name and pins of the group. Maintaining the data structure of
+the groups is up to the driver, this is just a simple example - in practice you
+may need more entries in your group structure, for example specific register
+ranges associated with each group and so on.
 
 
 Pin configuration
@@ -606,11 +603,9 @@ static const struct foo_group foo_groups[] = {
 };
 
 
-static int foo_list_groups(struct pinctrl_dev *pctldev, unsigned selector)
+static int foo_get_groups_count(struct pinctrl_dev *pctldev)
 {
-	if (selector >= ARRAY_SIZE(foo_groups))
-		return -EINVAL;
-	return 0;
+	return ARRAY_SIZE(foo_groups);
 }
 
 static const char *foo_get_group_name(struct pinctrl_dev *pctldev,
@@ -629,7 +624,7 @@ static int foo_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
 }
 
 static struct pinctrl_ops foo_pctrl_ops = {
-	.list_groups = foo_list_groups,
+	.get_groups_count = foo_get_groups_count,
 	.get_group_name = foo_get_group_name,
 	.get_group_pins = foo_get_group_pins,
 };
@@ -663,11 +658,9 @@ static const struct foo_pmx_func foo_functions[] = {
 	},
 };
 
-int foo_list_funcs(struct pinctrl_dev *pctldev, unsigned selector)
+int foo_get_functions_count(struct pinctrl_dev *pctldev)
 {
-	if (selector >= ARRAY_SIZE(foo_functions))
-		return -EINVAL;
-	return 0;
+	return ARRAY_SIZE(foo_functions);
 }
 
 const char *foo_get_fname(struct pinctrl_dev *pctldev, unsigned selector)
@@ -703,7 +696,7 @@ void foo_disable(struct pinctrl_dev *pctldev, unsigned selector,
 }
 
 struct pinmux_ops foo_pmxops = {
-	.list_functions = foo_list_funcs,
+	.get_functions_count = foo_get_functions_count,
 	.get_function_name = foo_get_fname,
 	.get_function_groups = foo_get_groups,
 	.enable = foo_enable,

drivers/pinctrl/core.c

@@ -319,9 +319,10 @@ int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
 			       const char *pin_group)
 {
 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	unsigned ngroups = pctlops->get_groups_count(pctldev);
 	unsigned group_selector = 0;
 
-	while (pctlops->list_groups(pctldev, group_selector) >= 0) {
+	while (group_selector < ngroups) {
 		const char *gname = pctlops->get_group_name(pctldev,
 							    group_selector);
 		if (!strcmp(gname, pin_group)) {
@@ -941,12 +942,13 @@ static int pinctrl_groups_show(struct seq_file *s, void *what)
 {
 	struct pinctrl_dev *pctldev = s->private;
 	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
-	unsigned selector = 0;
+	unsigned ngroups, selector = 0;
 
+	ngroups = ops->get_groups_count(pctldev);
 	mutex_lock(&pinctrl_mutex);
 
 	seq_puts(s, "registered pin groups:\n");
-	while (ops->list_groups(pctldev, selector) >= 0) {
+	while (selector < ngroups) {
 		const unsigned *pins;
 		unsigned num_pins;
 		const char *gname = ops->get_group_name(pctldev, selector);
@@ -1261,7 +1263,7 @@ static int pinctrl_check_ops(struct pinctrl_dev *pctldev)
 	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
 
 	if (!ops ||
-	    !ops->list_groups ||
+	    !ops->get_groups_count ||
 	    !ops->get_group_name ||
 	    !ops->get_group_pins)
 		return -EINVAL;

drivers/pinctrl/pinconf.c

@@ -495,6 +495,7 @@ static int pinconf_groups_show(struct seq_file *s, void *what)
 	struct pinctrl_dev *pctldev = s->private;
 	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 	const struct pinconf_ops *ops = pctldev->desc->confops;
+	unsigned ngroups = pctlops->get_groups_count(pctldev);
 	unsigned selector = 0;
 
 	if (!ops || !ops->pin_config_group_get)
@@ -505,7 +506,7 @@ static int pinconf_groups_show(struct seq_file *s, void *what)
 
 	mutex_lock(&pinctrl_mutex);
 
-	while (pctlops->list_groups(pctldev, selector) >= 0) {
+	while (selector < ngroups) {
 		const char *gname = pctlops->get_group_name(pctldev, selector);
 
 		seq_printf(s, "%u (%s):", selector, gname);

drivers/pinctrl/pinctrl-pxa3xx.c

@@ -25,20 +25,18 @@ static struct pinctrl_gpio_range pxa3xx_pinctrl_gpio_range = {
 	.pin_base	= 0,
 };
 
-static int pxa3xx_list_groups(struct pinctrl_dev *pctrldev, unsigned selector)
+static int pxa3xx_get_groups_count(struct pinctrl_dev *pctrldev)
 {
 	struct pxa3xx_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
-	if (selector >= info->num_grps)
-		return -EINVAL;
-	return 0;
+
+	return info->num_grps;
 }
 
 static const char *pxa3xx_get_group_name(struct pinctrl_dev *pctrldev,
 					 unsigned selector)
 {
 	struct pxa3xx_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
-	if (selector >= info->num_grps)
-		return NULL;
+
 	return info->grps[selector].name;
 }
 
@@ -48,25 +46,23 @@ static int pxa3xx_get_group_pins(struct pinctrl_dev *pctrldev,
 				 unsigned *num_pins)
 {
 	struct pxa3xx_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
-	if (selector >= info->num_grps)
-		return -EINVAL;
+
 	*pins = info->grps[selector].pins;
 	*num_pins = info->grps[selector].npins;
 	return 0;
 }
 
 static struct pinctrl_ops pxa3xx_pctrl_ops = {
-	.list_groups	= pxa3xx_list_groups,
+	.get_groups_count = pxa3xx_get_groups_count,
 	.get_group_name	= pxa3xx_get_group_name,
 	.get_group_pins	= pxa3xx_get_group_pins,
 };
 
-static int pxa3xx_pmx_list_func(struct pinctrl_dev *pctrldev, unsigned func)
+static int pxa3xx_pmx_get_funcs_count(struct pinctrl_dev *pctrldev)
 {
 	struct pxa3xx_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
-	if (func >= info->num_funcs)
-		return -EINVAL;
-	return 0;
+
+	return info->num_funcs;
 }
 
 static const char *pxa3xx_pmx_get_func_name(struct pinctrl_dev *pctrldev,
@@ -170,7 +166,7 @@ static int pxa3xx_pmx_request_gpio(struct pinctrl_dev *pctrldev,
 }
 
 static struct pinmux_ops pxa3xx_pmx_ops = {
-	.list_functions		= pxa3xx_pmx_list_func,
+	.get_functions_count	= pxa3xx_pmx_get_funcs_count,
 	.get_function_name	= pxa3xx_pmx_get_func_name,
 	.get_function_groups	= pxa3xx_pmx_get_groups,
 	.enable			= pxa3xx_pmx_enable,

drivers/pinctrl/pinctrl-sirf.c

@@ -853,18 +853,14 @@ static const struct sirfsoc_pin_group sirfsoc_pin_groups[] = {
 	SIRFSOC_PIN_GROUP("gpsgrp", gps_pins),
 };
 
-static int sirfsoc_list_groups(struct pinctrl_dev *pctldev, unsigned selector)
+static int sirfsoc_get_groups_count(struct pinctrl_dev *pctldev)
 {
-	if (selector >= ARRAY_SIZE(sirfsoc_pin_groups))
-		return -EINVAL;
-	return 0;
+	return ARRAY_SIZE(sirfsoc_pin_groups);
 }
 
 static const char *sirfsoc_get_group_name(struct pinctrl_dev *pctldev,
 				       unsigned selector)
 {
-	if (selector >= ARRAY_SIZE(sirfsoc_pin_groups))
-		return NULL;
 	return sirfsoc_pin_groups[selector].name;
 }
 
@@ -872,8 +868,6 @@ static int sirfsoc_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector
 			       const unsigned **pins,
 			       unsigned *num_pins)
 {
-	if (selector >= ARRAY_SIZE(sirfsoc_pin_groups))
-		return -EINVAL;
 	*pins = sirfsoc_pin_groups[selector].pins;
 	*num_pins = sirfsoc_pin_groups[selector].num_pins;
 	return 0;
@@ -886,7 +880,7 @@ static void sirfsoc_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s
 }
 
 static struct pinctrl_ops sirfsoc_pctrl_ops = {
-	.list_groups = sirfsoc_list_groups,
+	.get_groups_count = sirfsoc_get_groups_count,
 	.get_group_name = sirfsoc_get_group_name,
 	.get_group_pins = sirfsoc_get_group_pins,
 	.pin_dbg_show = sirfsoc_pin_dbg_show,
@@ -1033,11 +1027,9 @@ static void sirfsoc_pinmux_disable(struct pinctrl_dev *pmxdev, unsigned selector
 	sirfsoc_pinmux_endisable(spmx, selector, false);
 }
 
-static int sirfsoc_pinmux_list_funcs(struct pinctrl_dev *pmxdev, unsigned selector)
+static int sirfsoc_pinmux_get_funcs_count(struct pinctrl_dev *pmxdev)
 {
-	if (selector >= ARRAY_SIZE(sirfsoc_pmx_functions))
-		return -EINVAL;
-	return 0;
+	return ARRAY_SIZE(sirfsoc_pmx_functions);
 }
 
 static const char *sirfsoc_pinmux_get_func_name(struct pinctrl_dev *pctldev,
@@ -1074,9 +1066,9 @@ static int sirfsoc_pinmux_request_gpio(struct pinctrl_dev *pmxdev,
 }
 
 static struct pinmux_ops sirfsoc_pinmux_ops = {
-	.list_functions = sirfsoc_pinmux_list_funcs,
 	.enable = sirfsoc_pinmux_enable,
 	.disable = sirfsoc_pinmux_disable,
+	.get_functions_count = sirfsoc_pinmux_get_funcs_count,
 	.get_function_name = sirfsoc_pinmux_get_func_name,
 	.get_function_groups = sirfsoc_pinmux_get_groups,
 	.gpio_request_enable = sirfsoc_pinmux_request_gpio,

drivers/pinctrl/pinctrl-tegra.c

@@ -53,15 +53,11 @@ static inline void pmx_writel(struct tegra_pmx *pmx, u32 val, u32 bank, u32 reg)
 	writel(val, pmx->regs[bank] + reg);
 }
 
-static int tegra_pinctrl_list_groups(struct pinctrl_dev *pctldev,
-				     unsigned group)
+static int tegra_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
 {
 	struct tegra_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
 
-	if (group >= pmx->soc->ngroups)
-		return -EINVAL;
-
-	return 0;
+	return pmx->soc->ngroups;
 }
 
 static const char *tegra_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
@@ -69,9 +65,6 @@ static const char *tegra_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
 {
 	struct tegra_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
 
-	if (group >= pmx->soc->ngroups)
-		return NULL;
-
 	return pmx->soc->groups[group].name;
 }
 
@@ -82,9 +75,6 @@ static int tegra_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
 {
 	struct tegra_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
 
-	if (group >= pmx->soc->ngroups)
-		return -EINVAL;
-
 	*pins = pmx->soc->groups[group].pins;
 	*num_pins = pmx->soc->groups[group].npins;
 
@@ -99,21 +89,17 @@ static void tegra_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
 }
 
 static struct pinctrl_ops tegra_pinctrl_ops = {
-	.list_groups = tegra_pinctrl_list_groups,
+	.get_groups_count = tegra_pinctrl_get_groups_count,
 	.get_group_name = tegra_pinctrl_get_group_name,
 	.get_group_pins = tegra_pinctrl_get_group_pins,
 	.pin_dbg_show = tegra_pinctrl_pin_dbg_show,
 };
 
-static int tegra_pinctrl_list_funcs(struct pinctrl_dev *pctldev,
-				    unsigned function)
+static int tegra_pinctrl_get_funcs_count(struct pinctrl_dev *pctldev)
 {
 	struct tegra_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
 
-	if (function >= pmx->soc->nfunctions)
-		return -EINVAL;
-
-	return 0;
+	return pmx->soc->nfunctions;
 }
 
 static const char *tegra_pinctrl_get_func_name(struct pinctrl_dev *pctldev,
@@ -121,9 +107,6 @@ static const char *tegra_pinctrl_get_func_name(struct pinctrl_dev *pctldev,
 {
 	struct tegra_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
 
-	if (function >= pmx->soc->nfunctions)
-		return NULL;
-
 	return pmx->soc->functions[function].name;
 }
 
@@ -134,9 +117,6 @@ static int tegra_pinctrl_get_func_groups(struct pinctrl_dev *pctldev,
 {
 	struct tegra_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
 
-	if (function >= pmx->soc->nfunctions)
-		return -EINVAL;
-
 	*groups = pmx->soc->functions[function].groups;
 	*num_groups = pmx->soc->functions[function].ngroups;
 
@@ -151,8 +131,6 @@ static int tegra_pinctrl_enable(struct pinctrl_dev *pctldev, unsigned function,
 	int i;
 	u32 val;
 
-	if (group >= pmx->soc->ngroups)
-		return -EINVAL;
 	g = &pmx->soc->groups[group];
 
 	if (g->mux_reg < 0)
@@ -180,8 +158,6 @@ static void tegra_pinctrl_disable(struct pinctrl_dev *pctldev,
 	const struct tegra_pingroup *g;
 	u32 val;
 
-	if (group >= pmx->soc->ngroups)
-		return;
 	g = &pmx->soc->groups[group];
 
 	if (g->mux_reg < 0)
@@ -194,7 +170,7 @@ static void tegra_pinctrl_disable(struct pinctrl_dev *pctldev,
 }
 
 static struct pinmux_ops tegra_pinmux_ops = {
-	.list_functions = tegra_pinctrl_list_funcs,
+	.get_functions_count = tegra_pinctrl_get_funcs_count,
 	.get_function_name = tegra_pinctrl_get_func_name,
 	.get_function_groups = tegra_pinctrl_get_func_groups,
 	.enable = tegra_pinctrl_enable,
@@ -324,8 +300,6 @@ static int tegra_pinconf_group_get(struct pinctrl_dev *pctldev,
 	s16 reg;
 	u32 val, mask;
 
-	if (group >= pmx->soc->ngroups)
-		return -EINVAL;
 	g = &pmx->soc->groups[group];
 
 	ret = tegra_pinconf_reg(pmx, g, param, &bank, &reg, &bit, &width);
@@ -353,8 +327,6 @@ static int tegra_pinconf_group_set(struct pinctrl_dev *pctldev,
 	s16 reg;
 	u32 val, mask;
 
-	if (group >= pmx->soc->ngroups)
-		return -EINVAL;
 	g = &pmx->soc->groups[group];
 
 	ret = tegra_pinconf_reg(pmx, g, param, &bank, &reg, &bit, &width);

drivers/pinctrl/pinctrl-u300.c

@@ -836,18 +836,14 @@ static const struct u300_pin_group u300_pin_groups[] = {
 	},
 };
 
-static int u300_list_groups(struct pinctrl_dev *pctldev, unsigned selector)
+static int u300_get_groups_count(struct pinctrl_dev *pctldev)
 {
-	if (selector >= ARRAY_SIZE(u300_pin_groups))
-		return -EINVAL;
-	return 0;
+	return ARRAY_SIZE(u300_pin_groups);
 }
 
 static const char *u300_get_group_name(struct pinctrl_dev *pctldev,
 				       unsigned selector)
 {
-	if (selector >= ARRAY_SIZE(u300_pin_groups))
-		return NULL;
 	return u300_pin_groups[selector].name;
 }
 
@@ -855,8 +851,6 @@ static int u300_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
 			       const unsigned **pins,
 			       unsigned *num_pins)
 {
-	if (selector >= ARRAY_SIZE(u300_pin_groups))
-		return -EINVAL;
 	*pins = u300_pin_groups[selector].pins;
 	*num_pins = u300_pin_groups[selector].num_pins;
 	return 0;
@@ -869,7 +863,7 @@ static void u300_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
 }
 
 static struct pinctrl_ops u300_pctrl_ops = {
-	.list_groups = u300_list_groups,
+	.get_groups_count = u300_get_groups_count,
 	.get_group_name = u300_get_group_name,
 	.get_group_pins = u300_get_group_pins,
 	.pin_dbg_show = u300_pin_dbg_show,
@@ -991,11 +985,9 @@ static void u300_pmx_disable(struct pinctrl_dev *pctldev, unsigned selector,
 	u300_pmx_endisable(upmx, selector, false);
 }
 
-static int u300_pmx_list_funcs(struct pinctrl_dev *pctldev, unsigned selector)
+static int u300_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
 {
-	if (selector >= ARRAY_SIZE(u300_pmx_functions))
-		return -EINVAL;
-	return 0;
+	return ARRAY_SIZE(u300_pmx_functions);
 }
 
 static const char *u300_pmx_get_func_name(struct pinctrl_dev *pctldev,
@@ -1014,7 +1006,7 @@ static int u300_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
 }
 
 static struct pinmux_ops u300_pmx_ops = {
-	.list_functions = u300_pmx_list_funcs,
+	.get_functions_count = u300_pmx_get_funcs_count,
 	.get_function_name = u300_pmx_get_func_name,
 	.get_function_groups = u300_pmx_get_groups,
 	.enable = u300_pmx_enable,

drivers/pinctrl/pinmux.c

@@ -33,10 +33,11 @@
 int pinmux_check_ops(struct pinctrl_dev *pctldev)
 {
 	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	unsigned nfuncs = ops->get_functions_count(pctldev);
 	unsigned selector = 0;
 
 	/* Check that we implement required operations */
-	if (!ops->list_functions ||
+	if (!ops->get_functions_count ||
 	    !ops->get_function_name ||
 	    !ops->get_function_groups ||
 	    !ops->enable ||
@@ -44,7 +45,7 @@ int pinmux_check_ops(struct pinctrl_dev *pctldev)
 		return -EINVAL;
 
 	/* Check that all functions registered have names */
-	while (ops->list_functions(pctldev, selector) >= 0) {
+	while (selector < nfuncs) {
 		const char *fname = ops->get_function_name(pctldev,
 							   selector);
 		if (!fname) {
@@ -287,10 +288,11 @@ static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
 					const char *function)
 {
 	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	unsigned nfuncs = ops->get_functions_count(pctldev);
 	unsigned selector = 0;
 
 	/* See if this pctldev has this function */
-	while (ops->list_functions(pctldev, selector) >= 0) {
+	while (selector < nfuncs) {
 		const char *fname = ops->get_function_name(pctldev,
 							   selector);
 
@@ -477,11 +479,12 @@ static int pinmux_functions_show(struct seq_file *s, void *what)
 {
 	struct pinctrl_dev *pctldev = s->private;
 	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	unsigned nfuncs = pmxops->get_functions_count(pctldev);
 	unsigned func_selector = 0;
 
 	mutex_lock(&pinctrl_mutex);
 
-	while (pmxops->list_functions(pctldev, func_selector) >= 0) {
+	while (func_selector < nfuncs) {
 		const char *func = pmxops->get_function_name(pctldev,
 							  func_selector);
 		const char * const *groups;

include/linux/pinctrl/pinctrl.h

@@ -66,9 +66,7 @@ struct pinctrl_gpio_range {
 /**
  * struct pinctrl_ops - global pin control operations, to be implemented by
  * pin controller drivers.
- * @list_groups: list the number of selectable named groups available
- *	in this pinmux driver, the core will begin on 0 and call this
- *	repeatedly as long as it returns >= 0 to enumerate the groups
+ * @get_groups_count: Returns the count of total number of groups registered.
  * @get_group_name: return the group name of the pin group
  * @get_group_pins: return an array of pins corresponding to a certain
  *	group selector @pins, and the size of the array in @num_pins
@@ -76,7 +74,7 @@ struct pinctrl_gpio_range {
  *	info for a certain pin in debugfs
  */
 struct pinctrl_ops {
-	int (*list_groups) (struct pinctrl_dev *pctldev, unsigned selector);
+	int (*get_groups_count) (struct pinctrl_dev *pctldev);
 	const char *(*get_group_name) (struct pinctrl_dev *pctldev,
 				       unsigned selector);
 	int (*get_group_pins) (struct pinctrl_dev *pctldev,

include/linux/pinctrl/pinmux.h

@@ -29,9 +29,8 @@ struct pinctrl_dev;
  *	is allowed to answer "no" by returning a negative error code
  * @free: the reverse function of the request() callback, frees a pin after
  *	being requested
- * @list_functions: list the number of selectable named functions available
- *	in this pinmux driver, the core will begin on 0 and call this
- *	repeatedly as long as it returns >= 0 to enumerate mux settings
+ * @get_functions_count: returns number of selectable named functions available
+ *	in this pinmux driver
  * @get_function_name: return the function name of the muxing selector,
  *	called by the core to figure out which mux setting it shall map a
  *	certain device to
@@ -62,7 +61,7 @@ struct pinctrl_dev;
 struct pinmux_ops {
 	int (*request) (struct pinctrl_dev *pctldev, unsigned offset);
 	int (*free) (struct pinctrl_dev *pctldev, unsigned offset);
-	int (*list_functions) (struct pinctrl_dev *pctldev, unsigned selector);
+	int (*get_functions_count) (struct pinctrl_dev *pctldev);
 	const char *(*get_function_name) (struct pinctrl_dev *pctldev,
 					  unsigned selector);
 	int (*get_function_groups) (struct pinctrl_dev *pctldev,