pinctrl: imx: add generic pin config core support

The design is based on the exist architecture that the core will
provide a uniformed way to decode the generic pin config into platform
config register raw data according to the imx_cfg_params_decode maps
registered by platform.

Two useful macros, IMX_CFG_PARAMS_DECODE and IMX_CFG_PARAMS_DECODE_INVERT,
are created for platform to register decode map conveniently.

In order to cope with some special case, a platform specific fixup()
function is also available to use.

Note that rather than fully utilizing the generic pinconf support
provided by pinctrl core, IMX only adopts the device tree bindings
of generic pinconf. The config used in .pin_config_get[set] are raw
register data instead of generic one which makes us align the exist
using. And that's also why we cannot set pinconf_ops.is_generic.

Cc: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/freescale/Kconfig

@@ -2,7 +2,7 @@ config PINCTRL_IMX
 	bool
 	select GENERIC_PINCTRL_GROUPS
 	select GENERIC_PINMUX_FUNCTIONS
-	select PINCONF
+	select GENERIC_PINCONF
 	select REGMAP
 
 config PINCTRL_IMX1_CORE

drivers/pinctrl/freescale/pinctrl-imx.c

@@ -27,6 +27,7 @@
 #include <linux/regmap.h>
 
 #include "../core.h"
+#include "../pinconf.h"
 #include "../pinmux.h"
 #include "pinctrl-imx.h"
 
@@ -361,6 +362,62 @@ static const struct pinmux_ops imx_pmx_ops = {
 	.gpio_set_direction = imx_pmx_gpio_set_direction,
 };
 
+/* decode generic config into raw register values */
+static u32 imx_pinconf_decode_generic_config(struct imx_pinctrl *ipctl,
+					      unsigned long *configs,
+					      unsigned int num_configs)
+{
+	struct imx_pinctrl_soc_info *info = ipctl->info;
+	struct imx_cfg_params_decode *decode;
+	enum pin_config_param param;
+	u32 raw_config = 0;
+	u32 param_val;
+	int i, j;
+
+	WARN_ON(num_configs > info->num_decodes);
+
+	for (i = 0; i < num_configs; i++) {
+		param = pinconf_to_config_param(configs[i]);
+		param_val = pinconf_to_config_argument(configs[i]);
+		decode = info->decodes;
+		for (j = 0; j < info->num_decodes; j++) {
+			if (param == decode->param) {
+				if (decode->invert)
+					param_val = !param_val;
+				raw_config |= (param_val << decode->shift)
+					      & decode->mask;
+				break;
+			}
+			decode++;
+		}
+	}
+
+	if (info->fixup)
+		info->fixup(configs, num_configs, &raw_config);
+
+	return raw_config;
+}
+
+static u32 imx_pinconf_parse_generic_config(struct device_node *np,
+					    struct imx_pinctrl *ipctl)
+{
+	struct imx_pinctrl_soc_info *info = ipctl->info;
+	struct pinctrl_dev *pctl = ipctl->pctl;
+	unsigned int num_configs;
+	unsigned long *configs;
+	int ret;
+
+	if (!info->generic_pinconf)
+		return 0;
+
+	ret = pinconf_generic_parse_dt_config(np, pctl, &configs,
+					      &num_configs);
+	if (ret)
+		return 0;
+
+	return imx_pinconf_decode_generic_config(ipctl, configs, num_configs);
+}
+
 static int imx_pinconf_get(struct pinctrl_dev *pctldev,
 			     unsigned pin_id, unsigned long *config)
 {
@@ -479,9 +536,10 @@ static const struct pinconf_ops imx_pinconf_ops = {
 
 static int imx_pinctrl_parse_groups(struct device_node *np,
 				    struct group_desc *grp,
-				    struct imx_pinctrl_soc_info *info,
+				    struct imx_pinctrl *ipctl,
 				    u32 index)
 {
+	struct imx_pinctrl_soc_info *info = ipctl->info;
 	int size, pin_size;
 	const __be32 *list;
 	int i;
@@ -493,25 +551,44 @@ static int imx_pinctrl_parse_groups(struct device_node *np,
 		pin_size = SHARE_FSL_PIN_SIZE;
 	else
 		pin_size = FSL_PIN_SIZE;
+
+	if (info->generic_pinconf)
+		pin_size -= 4;
+
 	/* Initialise group */
 	grp->name = np->name;
 
 	/*
 	 * the binding format is fsl,pins = <PIN_FUNC_ID CONFIG ...>,
 	 * do sanity check and calculate pins number
+	 *
+	 * First try legacy 'fsl,pins' property, then fall back to the
+	 * generic 'pins'.
+	 *
+	 * Note: for generic 'pins' case, there's no CONFIG part in
+	 * the binding format.
 	 */
 	list = of_get_property(np, "fsl,pins", &size);
 	if (!list) {
-		dev_err(info->dev, "no fsl,pins property in node %s\n", np->full_name);
+		list = of_get_property(np, "pins", &size);
+		if (!list) {
+			dev_err(info->dev,
+				"no fsl,pins and pins property in node %s\n",
+				np->full_name);
 			return -EINVAL;
 		}
+	}
 
 	/* we do not check return since it's safe node passed down */
 	if (!size || size % pin_size) {
-		dev_err(info->dev, "Invalid fsl,pins property in node %s\n", np->full_name);
+		dev_err(info->dev, "Invalid fsl,pins or pins property in node %s\n",
+			np->full_name);
 		return -EINVAL;
 	}
 
+	/* first try to parse the generic pin config */
+	config = imx_pinconf_parse_generic_config(np, ipctl);
+
 	grp->num_pins = size / pin_size;
 	grp->data = devm_kzalloc(info->dev, grp->num_pins *
 				 sizeof(struct imx_pin), GFP_KERNEL);
@@ -548,11 +625,18 @@ static int imx_pinctrl_parse_groups(struct device_node *np,
 		pin->mux_mode = be32_to_cpu(*list++);
 		pin->input_val = be32_to_cpu(*list++);
 
-		/* SION bit is in mux register */
+		if (info->generic_pinconf) {
+			/* generic pin config decoded */
+			pin->config = config;
+		} else {
+			/* legacy pin config read from devicetree */
 			config = be32_to_cpu(*list++);
+
+			/* SION bit is in mux register */
 			if (config & IMX_PAD_SION)
 				pin->mux_mode |= IOMUXC_CONFIG_SION;
 			pin->config = config & ~IMX_PAD_SION;
+		}
 
 		dev_dbg(info->dev, "%s: 0x%x 0x%08lx", info->pins[pin_id].name,
 				pin->mux_mode, pin->config);
@@ -603,7 +687,7 @@ static int imx_pinctrl_parse_functions(struct device_node *np,
 				  info->group_index++, grp);
 		mutex_unlock(&info->mutex);
 
-		imx_pinctrl_parse_groups(child, grp, info, i++);
+		imx_pinctrl_parse_groups(child, grp, ipctl, i++);
 	}
 
 	return 0;
@@ -774,6 +858,10 @@ int imx_pinctrl_probe(struct platform_device *pdev,
 	imx_pinctrl_desc->confops = &imx_pinconf_ops;
 	imx_pinctrl_desc->owner = THIS_MODULE;
 
+	/* for generic pinconf */
+	imx_pinctrl_desc->custom_params = info->custom_params;
+	imx_pinctrl_desc->num_custom_params = info->num_custom_params;
+
 	mutex_init(&info->mutex);
 
 	ipctl->info = info;

drivers/pinctrl/freescale/pinctrl-imx.h

@@ -15,6 +15,8 @@
 #ifndef __DRIVERS_PINCTRL_IMX_H
 #define __DRIVERS_PINCTRL_IMX_H
 
+#include <linux/pinctrl/pinconf-generic.h>
+
 struct platform_device;
 
 /**
@@ -44,6 +46,14 @@ struct imx_pin_reg {
 	s16 conf_reg;
 };
 
+/* decode a generic config into raw register value */
+struct imx_cfg_params_decode {
+	enum pin_config_param param;
+	u32 mask;
+	u8 shift;
+	bool invert;
+};
+
 struct imx_pinctrl_soc_info {
 	struct device *dev;
 	const struct pinctrl_pin_desc *pins;
@@ -53,8 +63,23 @@ struct imx_pinctrl_soc_info {
 	unsigned int flags;
 	const char *gpr_compatible;
 	struct mutex mutex;
+
+	/* generic pinconf */
+	bool generic_pinconf;
+	const struct pinconf_generic_params *custom_params;
+	unsigned int num_custom_params;
+	struct imx_cfg_params_decode *decodes;
+	unsigned int num_decodes;
+	void (*fixup)(unsigned long *configs, unsigned int num_configs,
+		      u32 *raw_config);
 };
 
+#define IMX_CFG_PARAMS_DECODE(p, m, o) \
+	{ .param = p, .mask = m, .shift = o, .invert = false, }
+
+#define IMX_CFG_PARAMS_DECODE_INVERT(p, m, o) \
+	{ .param = p, .mask = m, .shift = o, .invert = true, }
+
 #define SHARE_MUX_CONF_REG	0x1
 #define ZERO_OFFSET_VALID	0x2