[PATCH 1/1] pinctrl: Add alternative way for specifying register bases

[Light Hsieh <light.hsieh@xxxxxxxxxxxx>]

The orginal PINCTRL_MTK_PARIS/PINCTRL_MTK_MOORE need more effort for
specifying register bases when porting platform driver:
1. Write mtXXXX_pinctrl_register_base_name[] array in pinctrl-mtXXXX.c
   to specify names of register bases, for exmaple:

   	static const char * const mt6765_pinctrl_register_base_names[] = {
		"iocfg0", "iocfg1", "iocfg2", "iocfg3", "iocfg4", "iocfg5",
		"iocfg6", "iocfg7",
   	};
2. Write reg = <...>, ..., <...>; in mtXXXX.dts to specify register
   bases. Each member of reg contain address range cloned from
   pre-generated devicetree node.
3. Write reg-names = "...", ..., "..."; in mtXXXX.dts to specify
   names of register bases. The sequence of names in reg-names shall match
   sequence of names that specified in pinctrl-mtXXXX.c.
   Besides, the seqeunce of names in reg-names shall also match sequence of
   address range in reg, for exmaple:

   	pio: pinctrl {
		compatible = "mediatek,mt6765-pinctrl";
		reg = <0 0x10005000 0 0x1000>,
		      <0 0x10002C00 0 0x200>,
		      <0 0x10002800 0 0x200>,
		      <0 0x10002A00 0 0x200>,
		      <0 0x10002000 0 0x200>,
		      <0 0x10002200 0 0x200>,
		      <0 0x10002400 0 0x200>,
		      <0 0x10002600 0 0x200>,
		      <0 0x1000b000 0 0x1000>;
		reg-names = "iocfg0", "iocfg1", "iocfg2", "iocfg3",
			    "iocfg4", "iocfg5", "iocfg6", "iocfg7",
			    "eint";

To reduce porting effort, this patch add an alternative way for specifying
register bases:
1. Write reg_bases = <...>, ..., <...>; and reg_base_eint = <&eint>;
   in mtXXXX.dtsi where members in reg_bases and &eint are labels for
   pre-generated devicetree nodes, for example:
	pio: pinctrl {
		compatible = "mediatek,mt6765-pinctrl";
		reg_bases = <&gpio0>,
			    <&iocfg0>,
			    <&iocfg1>,
			    <&iocfg2>,
			    <&iocfg3>,
			    <&iocfg4>,
			    <&iocfg5>,
			    <&iocfg6>,
			    <&iocfg7>;
		reg_base_eint = <&eint>;

   Since this pre-generated nodes had already specify address range,
   it is not necessary to specify address range again in pinctrl node.

Using this way, porting effort is reduced and therefore typo can occur with
less chance.

Change-Id: I55f5e328919f4f736ca4b9f8d1593e069f179637
---
 drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 19 +++++---
 drivers/pinctrl/mediatek/pinctrl-paris.c         | 62 ++++++++++++++++--------
 2 files changed, 54 insertions(+), 27 deletions(-)

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
index b1c3684..16b4863 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
@@ -12,6 +12,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/of_irq.h>
+#include <linux/of_address.h>
 
 #include "mtk-eint.h"
 #include "pinctrl-mtk-common-v2.h"
@@ -310,7 +311,7 @@ static int mtk_xt_set_gpio_as_eint(void *data, unsigned long eint_n)
 
 int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
 {
-	struct device_node *np = pdev->dev.of_node;
+	struct device_node *np = pdev->dev.of_node, *node;
 	struct resource *res;
 
 	if (!IS_ENABLED(CONFIG_EINT_MTK))
@@ -323,13 +324,19 @@ int mtk_build_eint(struct mtk_pinctrl *hw, struct platform_device *pdev)
 	if (!hw->eint)
 		return -ENOMEM;
 
-	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "eint");
-	if (!res) {
-		dev_err(&pdev->dev, "Unable to get eint resource\n");
-		return -ENODEV;
+	node = of_parse_phandle(np, "reg_base_eint", 0);
+	if (node) {
+		hw->eint->base = of_iomap(node, 0);
+	} else {
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+			"eint");
+		if (!res) {
+			dev_err(&pdev->dev, "Unable to get eint resource\n");
+			return -ENODEV;
+		}
+		hw->eint->base = devm_ioremap_resource(&pdev->dev, res);
 	}
 
-	hw->eint->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(hw->eint->base))
 		return PTR_ERR(hw->eint->base);
 
diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index b59e108..8ddb995 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -9,6 +9,7 @@
  *	   Hongzhou.Yang <hongzhou.yang@xxxxxxxxxxxx>
  */
 
+#include <linux/of_address.h>
 #include <linux/gpio/driver.h>
 #include <dt-bindings/pinctrl/mt65xx.h>
 #include "pinctrl-paris.h"
@@ -815,10 +816,11 @@ static int mtk_pctrl_build_state(struct platform_device *pdev)
 int mtk_paris_pinctrl_probe(struct platform_device *pdev,
 			    const struct mtk_pin_soc *soc)
 {
+	struct device_node *np = pdev->dev.of_node, *node;
 	struct pinctrl_pin_desc *pins;
 	struct mtk_pinctrl *hw;
 	struct resource *res;
-	int err, i;
+	int err, i, get_base_pass;
 
 	hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL);
 	if (!hw)
@@ -828,31 +830,49 @@ int mtk_paris_pinctrl_probe(struct platform_device *pdev,
 	hw->soc = soc;
 	hw->dev = &pdev->dev;
 
-	if (!hw->soc->nbase_names) {
-		dev_err(&pdev->dev,
-			"SoC should be assigned at least one register base\n");
-		return -EINVAL;
-	}
-
-	hw->base = devm_kmalloc_array(&pdev->dev, hw->soc->nbase_names,
+	if (hw->soc->nbase_names) {
+		hw->base = devm_kmalloc_array(&pdev->dev, hw->soc->nbase_names,
 				      sizeof(*hw->base), GFP_KERNEL);
-	if (!hw->base)
-		return -ENOMEM;
+		if (!hw->base)
+			return -ENOMEM;
+
+		for (i = 0; i < hw->soc->nbase_names; i++) {
+			res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+							hw->soc->base_names[i]);
+			if (!res) {
+				dev_err(&pdev->dev, "missing IO resource\n");
+				return -ENXIO;
+			}
 
-	for (i = 0; i < hw->soc->nbase_names; i++) {
-		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
-						   hw->soc->base_names[i]);
-		if (!res) {
-			dev_err(&pdev->dev, "missing IO resource\n");
-			return -ENXIO;
+			hw->base[i] = devm_ioremap_resource(&pdev->dev, res);
+			if (IS_ERR(hw->base[i]))
+				return PTR_ERR(hw->base[i]);
 		}
 
-		hw->base[i] = devm_ioremap_resource(&pdev->dev, res);
-		if (IS_ERR(hw->base[i]))
-			return PTR_ERR(hw->base[i]);
-	}
+		hw->nbase = hw->soc->nbase_names;
+	} else {
+		for (get_base_pass = 0; get_base_pass < 2; get_base_pass++) {
+			for (i = 0;; i++) {
+				node = of_parse_phandle(np, "reg_bases", i);
+				if (!node)
+					break;
+				if (get_base_pass == 1)
+					hw->base[i] = of_iomap(node, 0);
+				of_node_put(node);
+			}
 
-	hw->nbase = hw->soc->nbase_names;
+			if (i == 0)
+				return -EINVAL;
+			if (get_base_pass == 0) {
+				hw->nbase = i;
+				hw->base = devm_kmalloc_array(&pdev->dev, i,
+					sizeof(*hw->base),
+					GFP_KERNEL | __GFP_ZERO);
+				if (IS_ERR(hw->base))
+					return PTR_ERR(hw->base);
+			}
+		}
+	}
 
 	err = mtk_pctrl_build_state(pdev);
 	if (err) {
-- 
1.8.1.1.dirty