pinctrl: bcm2835: Add support for generic pinctrl binding

To keep driver up to date we add generic pinctrl binding support, which
covers the features used in this driver and has additional node properties
that this SoC has compatibility, so enabling future implementations of
these properties without the need to create new node properties in the
device trees.

The logic of this change maintain the old brcm legacy binding support in
order to keep the ABI stable.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/bcm/Kconfig

@@ -20,6 +20,7 @@ config PINCTRL_BCM2835
 	bool
 	select PINMUX
 	select PINCONF
+	select GENERIC_PINCONF
 	select GPIOLIB_IRQCHIP
 
 config PINCTRL_IPROC_GPIO

drivers/pinctrl/bcm/pinctrl-bcm2835.c

@@ -36,11 +36,13 @@
 #include <linux/pinctrl/pinconf.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf-generic.h>
 #include <linux/platform_device.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
+#include <dt-bindings/pinctrl/bcm2835.h>
 
 #define MODULE_NAME "pinctrl-bcm2835"
 #define BCM2835_NUM_GPIOS 54
@@ -72,13 +74,9 @@
 
 enum bcm2835_pinconf_param {
 	/* argument: bcm2835_pinconf_pull */
-	BCM2835_PINCONF_PARAM_PULL,
+	BCM2835_PINCONF_PARAM_PULL = (PIN_CONFIG_END + 1),
 };
 
-#define BCM2835_PINCONF_PACK(_param_, _arg_) ((_param_) << 16 | (_arg_))
-#define BCM2835_PINCONF_UNPACK_PARAM(_conf_) ((_conf_) >> 16)
-#define BCM2835_PINCONF_UNPACK_ARG(_conf_) ((_conf_) & 0xffff)
-
 struct bcm2835_pinctrl {
 	struct device *dev;
 	void __iomem *base;
@@ -213,14 +211,6 @@ static const char * const bcm2835_gpio_groups[] = {
 };
 
 enum bcm2835_fsel {
-	BCM2835_FSEL_GPIO_IN = 0,
-	BCM2835_FSEL_GPIO_OUT = 1,
-	BCM2835_FSEL_ALT0 = 4,
-	BCM2835_FSEL_ALT1 = 5,
-	BCM2835_FSEL_ALT2 = 6,
-	BCM2835_FSEL_ALT3 = 7,
-	BCM2835_FSEL_ALT4 = 3,
-	BCM2835_FSEL_ALT5 = 2,
 	BCM2835_FSEL_COUNT = 8,
 	BCM2835_FSEL_MASK = 0x7,
 };
@@ -714,7 +704,7 @@ static int bcm2835_pctl_dt_node_to_map_pull(struct bcm2835_pinctrl *pc,
 	configs = kzalloc(sizeof(*configs), GFP_KERNEL);
 	if (!configs)
 		return -ENOMEM;
-	configs[0] = BCM2835_PINCONF_PACK(BCM2835_PINCONF_PARAM_PULL, pull);
+	configs[0] = pinconf_to_config_packed(BCM2835_PINCONF_PARAM_PULL, pull);
 
 	map->type = PIN_MAP_TYPE_CONFIGS_PIN;
 	map->data.configs.group_or_pin = bcm2835_gpio_pins[pin].name;
@@ -727,7 +717,7 @@ static int bcm2835_pctl_dt_node_to_map_pull(struct bcm2835_pinctrl *pc,
 
 static int bcm2835_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
 		struct device_node *np,
-		struct pinctrl_map **map, unsigned *num_maps)
+		struct pinctrl_map **map, unsigned int *num_maps)
 {
 	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
 	struct property *pins, *funcs, *pulls;
@@ -736,6 +726,12 @@ static int bcm2835_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
 	int i, err;
 	u32 pin, func, pull;
 
+	/* Check for generic binding in this node */
+	err = pinconf_generic_dt_node_to_map_all(pctldev, np, map, num_maps);
+	if (err || *num_maps)
+		return err;
+
+	/* Generic binding did not find anything continue with legacy parse */
 	pins = of_find_property(np, "brcm,pins", NULL);
 	if (!pins) {
 		dev_err(pc->dev, "%pOF: missing brcm,pins property\n", np);
@@ -917,37 +913,62 @@ static int bcm2835_pinconf_get(struct pinctrl_dev *pctldev,
 	return -ENOTSUPP;
 }
 
+static void bcm2835_pull_config_set(struct bcm2835_pinctrl *pc,
+		unsigned int pin, unsigned int arg)
+{
+	u32 off, bit;
+
+	off = GPIO_REG_OFFSET(pin);
+	bit = GPIO_REG_SHIFT(pin);
+
+	bcm2835_gpio_wr(pc, GPPUD, arg & 3);
+	/*
+	 * BCM2835 datasheet say to wait 150 cycles, but not of what.
+	 * But the VideoCore firmware delay for this operation
+	 * based nearly on the same amount of VPU cycles and this clock
+	 * runs at 250 MHz.
+	 */
+	udelay(1);
+	bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), BIT(bit));
+	udelay(1);
+	bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), 0);
+}
+
 static int bcm2835_pinconf_set(struct pinctrl_dev *pctldev,
-			unsigned pin, unsigned long *configs,
-			unsigned num_configs)
+			unsigned int pin, unsigned long *configs,
+			unsigned int num_configs)
 {
 	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
-	enum bcm2835_pinconf_param param;
-	u16 arg;
-	u32 off, bit;
+	u32 param, arg;
 	int i;
 
 	for (i = 0; i < num_configs; i++) {
-		param = BCM2835_PINCONF_UNPACK_PARAM(configs[i]);
-		arg = BCM2835_PINCONF_UNPACK_ARG(configs[i]);
+		param = pinconf_to_config_param(configs[i]);
+		arg = pinconf_to_config_argument(configs[i]);
 
-		if (param != BCM2835_PINCONF_PARAM_PULL)
-			return -EINVAL;
+		switch (param) {
+		/* Set legacy brcm,pull */
+		case BCM2835_PINCONF_PARAM_PULL:
+			bcm2835_pull_config_set(pc, pin, arg);
+			break;
 
-		off = GPIO_REG_OFFSET(pin);
-		bit = GPIO_REG_SHIFT(pin);
+		/* Set pull generic bindings */
+		case PIN_CONFIG_BIAS_DISABLE:
+			bcm2835_pull_config_set(pc, pin, BCM2835_PUD_OFF);
+			break;
 
-		bcm2835_gpio_wr(pc, GPPUD, arg & 3);
-		/*
-		 * BCM2835 datasheet say to wait 150 cycles, but not of what.
-		 * But the VideoCore firmware delay for this operation
-		 * based nearly on the same amount of VPU cycles and this clock
-		 * runs at 250 MHz.
-		 */
-		udelay(1);
-		bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), BIT(bit));
-		udelay(1);
-		bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), 0);
+		case PIN_CONFIG_BIAS_PULL_DOWN:
+			bcm2835_pull_config_set(pc, pin, BCM2835_PUD_DOWN);
+			break;
+
+		case PIN_CONFIG_BIAS_PULL_UP:
+			bcm2835_pull_config_set(pc, pin, BCM2835_PUD_UP);
+			break;
+
+		default:
+			return -EINVAL;
+
+		} /* switch param type */
 	} /* for each config */
 
 	return 0;