pinctrl: single: Use generic parser and #pinctrl-cells for pinctrl-single,pins

We can now use generic parser. To support the legacy binding without
#pinctrl-cells, add pcs_quirk_missing_pinctrl_cells() and warn about
missing #pinctrl-cells.

Let's also update the documentation for struct pcs_soc_data while at it
as that seems to be out of date.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-single.c

@@ -31,10 +31,10 @@
 #include <linux/platform_data/pinctrl-single.h>
 
 #include "core.h"
+#include "devicetree.h"
 #include "pinconf.h"
 
 #define DRIVER_NAME			"pinctrl-single"
-#define PCS_MUX_PINS_NAME		"pinctrl-single,pins"
 #define PCS_MUX_BITS_NAME		"pinctrl-single,bits"
 #define PCS_OFF_DISABLED		~0U
 
@@ -162,8 +162,11 @@ struct pcs_soc_data {
  * @base:	virtual address of the controller
  * @size:	size of the ioremapped area
  * @dev:	device entry
+ * @np:		device tree node
  * @pctl:	pin controller device
  * @flags:	mask of PCS_FEAT_xxx values
+ * @missing_nr_pinctrl_cells: for legacy binding, may go away
+ * @socdata:	soc specific data
  * @lock:	spinlock for register access
  * @mutex:	mutex protecting the lists
  * @width:	bits per mux register
@@ -171,7 +174,8 @@ struct pcs_soc_data {
  * @fshift:	function register shift
  * @foff:	value to turn mux off
  * @fmax:	max number of functions in fmask
- * @bits_per_pin:number of bits per pin
+ * @bits_per_mux: number of bits per mux
+ * @bits_per_pin: number of bits per pin
  * @pins:	physical pins on the SoC
  * @pgtree:	pingroup index radix tree
  * @ftree:	function index radix tree
@@ -192,11 +196,13 @@ struct pcs_device {
 	void __iomem *base;
 	unsigned size;
 	struct device *dev;
+	struct device_node *np;
 	struct pinctrl_dev *pctl;
 	unsigned flags;
 #define PCS_QUIRK_SHARED_IRQ	(1 << 2)
 #define PCS_FEAT_IRQ		(1 << 1)
 #define PCS_FEAT_PINCONF	(1 << 0)
+	struct property *missing_nr_pinctrl_cells;
 	struct pcs_soc_data socdata;
 	raw_spinlock_t lock;
 	struct mutex mutex;
@@ -1122,20 +1128,14 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 						unsigned *num_maps,
 						const char **pgnames)
 {
+	const char *name = "pinctrl-single,pins";
 	struct pcs_func_vals *vals;
-	const __be32 *mux;
-	int size, rows, *pins, index = 0, found = 0, res = -ENOMEM;
+	int rows, *pins, found = 0, res = -ENOMEM, i;
 	struct pcs_function *function;
 
-	mux = of_get_property(np, PCS_MUX_PINS_NAME, &size);
-	if ((!mux) || (size < sizeof(*mux) * 2)) {
-		dev_err(pcs->dev, "bad data for mux %s\n",
-			np->name);
-		return -EINVAL;
-	}
-
-	size /= sizeof(*mux);	/* Number of elements in array */
-	rows = size / 2;
+	rows = pinctrl_count_index_with_args(np, name);
+	if (rows == -EINVAL)
+		return rows;
 
 	vals = devm_kzalloc(pcs->dev, sizeof(*vals) * rows, GFP_KERNEL);
 	if (!vals)
@@ -1145,14 +1145,28 @@ static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
 	if (!pins)
 		goto free_vals;
 
-	while (index < size) {
-		unsigned offset, val;
+	for (i = 0; i < rows; i++) {
+		struct of_phandle_args pinctrl_spec;
+		unsigned int offset;
 		int pin;
 
-		offset = be32_to_cpup(mux + index++);
-		val = be32_to_cpup(mux + index++);
+		res = pinctrl_parse_index_with_args(np, name, i, &pinctrl_spec);
+		if (res)
+			return res;
+
+		if (pinctrl_spec.args_count < 2) {
+			dev_err(pcs->dev, "invalid args_count for spec: %i\n",
+				pinctrl_spec.args_count);
+			break;
+		}
+
+		/* Index plus one value cell */
+		offset = pinctrl_spec.args[0];
 		vals[found].reg = pcs->base + offset;
-		vals[found].val = val;
+		vals[found].val = pinctrl_spec.args[1];
+
+		dev_dbg(pcs->dev, "%s index: 0x%x value: 0x%x\n",
+			pinctrl_spec.np->name, offset, pinctrl_spec.args[1]);
 
 		pin = pcs_get_pin_by_offset(pcs, offset);
 		if (pin < 0) {
@@ -1470,6 +1484,10 @@ static void pcs_free_resources(struct pcs_device *pcs)
 	pinctrl_unregister(pcs->pctl);
 	pcs_free_funcs(pcs);
 	pcs_free_pingroups(pcs);
+#if IS_BUILTIN(CONFIG_PINCTRL_SINGLE)
+	if (pcs->missing_nr_pinctrl_cells)
+		of_remove_property(pcs->np, pcs->missing_nr_pinctrl_cells);
+#endif
 }
 
 static const struct of_device_id pcs_of_match[];
@@ -1787,6 +1805,55 @@ static int pinctrl_single_resume(struct platform_device *pdev)
 }
 #endif
 
+/**
+ * pcs_quirk_missing_pinctrl_cells - handle legacy binding
+ * @pcs: pinctrl driver instance
+ * @np: device tree node
+ * @cells: number of cells
+ *
+ * Handle legacy binding with no #pinctrl-cells. This should be
+ * always two pinctrl-single,bit-per-mux and one for others.
+ * At some point we may want to consider removing this.
+ */
+static int pcs_quirk_missing_pinctrl_cells(struct pcs_device *pcs,
+					   struct device_node *np,
+					   int cells)
+{
+	struct property *p;
+	const char *name = "#pinctrl-cells";
+	int error;
+	u32 val;
+
+	error = of_property_read_u32(np, name, &val);
+	if (!error)
+		return 0;
+
+	dev_warn(pcs->dev, "please update dts to use %s = <%i>\n",
+		 name, cells);
+
+	p = devm_kzalloc(pcs->dev, sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	p->length = sizeof(__be32);
+	p->value = devm_kzalloc(pcs->dev, sizeof(__be32), GFP_KERNEL);
+	if (!p->value)
+		return -ENOMEM;
+	*(__be32 *)p->value = cpu_to_be32(cells);
+
+	p->name = devm_kstrdup(pcs->dev, name, GFP_KERNEL);
+	if (!p->name)
+		return -ENOMEM;
+
+	pcs->missing_nr_pinctrl_cells = p;
+
+#if IS_BUILTIN(CONFIG_PINCTRL_SINGLE)
+	error = of_add_property(np, pcs->missing_nr_pinctrl_cells);
+#endif
+
+	return error;
+}
+
 static int pcs_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -1807,6 +1874,7 @@ static int pcs_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 	pcs->dev = &pdev->dev;
+	pcs->np = np;
 	raw_spin_lock_init(&pcs->lock);
 	mutex_init(&pcs->mutex);
 	INIT_LIST_HEAD(&pcs->pingroups);
@@ -1843,6 +1911,13 @@ static int pcs_probe(struct platform_device *pdev)
 
 	pcs->bits_per_mux = of_property_read_bool(np,
 						  "pinctrl-single,bit-per-mux");
+	ret = pcs_quirk_missing_pinctrl_cells(pcs, np,
+					      pcs->bits_per_mux ? 2 : 1);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to patch #pinctrl-cells\n");
+
+		return ret;
+	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {