pinctrl: constify pinmux_generic_get_function()

With all users of struct function_desc limited to only accessing it using
the dedicated function and never modifying it, we can now constify the
return value of pinmux_generic_get_function() treewide.

Reviewed-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]> # renesas
Acked-by: Geert Uytterhoeven <[e-mail]> # renesas
Tested-by: Neil Armstrong <[e-mail]>
Signed-off-by: Bartosz Golaszewski <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/freescale/pinctrl-imx.c

···
 {
 	struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
 	const struct imx_pinctrl_soc_info *info = ipctl->info;
-	struct function_desc *func;
+	const struct function_desc *func;
 	struct group_desc *grp;
 	struct imx_pin *pin;
 	unsigned int npins;

drivers/pinctrl/mediatek/pinctrl-airoha.c

···
 {
 	struct airoha_pinctrl *pinctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 	const struct airoha_pinctrl_func *func;
-	struct function_desc *desc;
+	const struct function_desc *desc;
 	struct group_desc *grp;
 	int i;
 

drivers/pinctrl/mediatek/pinctrl-moore.c

···
 			      unsigned int selector, unsigned int group)
 {
 	struct mtk_pinctrl *hw = pinctrl_dev_get_drvdata(pctldev);
-	struct function_desc *func;
+	const struct function_desc *func;
 	struct group_desc *grp;
 	int i, err;
 

drivers/pinctrl/pinctrl-equilibrium.c

···
 			       unsigned int selector, unsigned int group)
 {
 	struct eqbr_pinctrl_drv_data *pctl = pinctrl_dev_get_drvdata(pctldev);
-	struct function_desc *func;
+	const struct function_desc *func;
 	struct group_desc *grp;
 	unsigned int *pinmux;
 	int i;

drivers/pinctrl/pinctrl-ingenic.c

···
 		unsigned int selector, unsigned int group)
 {
 	struct ingenic_pinctrl *jzpc = pinctrl_dev_get_drvdata(pctldev);
-	struct function_desc *func;
+	const struct function_desc *func;
 	struct group_desc *grp;
 	unsigned int i;
 	uintptr_t mode;

drivers/pinctrl/pinctrl-keembay.c

···
 			   unsigned int grp_sel)
 {
 	struct keembay_pinctrl *kpc = pinctrl_dev_get_drvdata(pctldev);
-	struct function_desc *func;
+	const struct function_desc *func;
 	struct group_desc *grp;
 	unsigned int val;
 	u8 pin_mode;

drivers/pinctrl/pinctrl-single.c

···
 	struct pcs_device *pcs = pinctrl_dev_get_drvdata(pctldev);
 	struct pin_desc *pdesc = pin_desc_get(pctldev, pin);
 	const struct pinctrl_setting_mux *setting;
-	struct function_desc *function;
+	const struct function_desc *function;
 	unsigned fselector;
 
 	/* If pin is not described in DTS & enabled, mux_setting is NULL. */
···
 	unsigned group)
 {
 	struct pcs_device *pcs;
-	struct function_desc *function;
+	const struct function_desc *function;
 	struct pcs_function *func;
 	int i;
 

drivers/pinctrl/pinmux.c

···
  * @pctldev: pin controller device
  * @selector: function number
  */
-struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
-						  unsigned int selector)
+const struct function_desc *
+pinmux_generic_get_function(struct pinctrl_dev *pctldev, unsigned int selector)
 {
 	struct function_desc *function;
 

drivers/pinctrl/pinmux.h

···
 				       const char * const **groups,
 				       unsigned int * const ngroups);
 
-struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
-						  unsigned int selector);
+const struct function_desc *
+pinmux_generic_get_function(struct pinctrl_dev *pctldev, unsigned int selector);
 
 int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
 				const char *name,

drivers/pinctrl/renesas/pinctrl-rza1.c

···
 {
 	struct rza1_pinctrl *rza1_pctl = pinctrl_dev_get_drvdata(pctldev);
 	struct rza1_mux_conf *mux_confs;
-	struct function_desc *func;
+	const struct function_desc *func;
 	struct group_desc *grp;
 	int i;
 

drivers/pinctrl/renesas/pinctrl-rza2.c

···
 			unsigned int group)
 {
 	struct rza2_pinctrl_priv *priv = pinctrl_dev_get_drvdata(pctldev);
-	struct function_desc *func;
+	const struct function_desc *func;
 	unsigned int i, *psel_val;
 	struct group_desc *grp;
 

drivers/pinctrl/renesas/pinctrl-rzg2l.c

···
 {
 	struct rzg2l_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
 	const struct rzg2l_hwcfg *hwcfg = pctrl->data->hwcfg;
-	struct function_desc *func;
+	const struct function_desc *func;
 	unsigned int i, *psel_val;
 	struct group_desc *group;
 	const unsigned int *pins;

drivers/pinctrl/renesas/pinctrl-rzv2m.c

···
 				 unsigned int group_selector)
 {
 	struct rzv2m_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
-	struct function_desc *func;
+	const struct function_desc *func;
 	unsigned int i, *psel_val;
 	struct group_desc *group;
 	const unsigned int *pins;