pinctrl: introduce generic pin config

This is a split-off from the earlier patch set which adds generic
pin configuration for the pin controllers that want it. Since
we may have a system with mixed generic and custom pin controllers,
we pass a boolean in the pin controller ops vtable to indicate
if it is generic.

ChangeLog v1->v5:
- Follow parent patch versioning number system.
- Document the semantic meaning of return values from pin config
  get functions, so we can iterate over pins and check their
  properties from debugfs as part of the generic config code.
- Use proper cast functions in the generic debugfs pin config
  file.
- Expand generic config to optionally cover groups too.
ChangeLog v5->v6:
- Update to match underlying changes.
ChangeLog v6->v7:
- Drop DRIVE_OFF parameter, use bias high impedance for this
- Delete argument for drive modes push-pull, od and os. These
  are now just state transitions.
- Delete slew rate rising/falling due to discussions on on
  proper semantics
- Drop config wakeup, struct irq_chip does this for now, add
  back if need be.
- Set PIN_CONFIG_END to 0x7fff making room for custom config
  parameters from 0x8000 and up.
- Prefix accessor functions with pinconf_

5 files changed, 170 insertions, 4 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index c6d29ff..07f3d8d 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -17,6 +17,10 @@ config PINMUX
 config PINCONF
 	bool "Support pin configuration controllers"
 
+config GENERIC_PINCONF
+	bool
+	select PINCONF
+
 config DEBUG_PINCTRL
 	bool "Debug PINCTRL calls"
 	depends on DEBUG_KERNEL
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 754329b..6d4150b 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -5,6 +5,7 @@ ccflags-$(CONFIG_DEBUG_PINCTRL)	+= -DDEBUG
 obj-$(CONFIG_PINCTRL)		+= core.o
 obj-$(CONFIG_PINMUX)		+= pinmux.o
 obj-$(CONFIG_PINCONF)		+= pinconf.o
+obj-$(CONFIG_GENERIC_PINCONF)	+= pinconf-generic.o
 obj-$(CONFIG_PINCTRL_PXA3xx)	+= pinctrl-pxa3xx.o
 obj-$(CONFIG_PINCTRL_MMP2)	+= pinctrl-mmp2.o
 obj-$(CONFIG_PINCTRL_PXA168)	+= pinctrl-pxa168.o
diff --git a/drivers/pinctrl/pinconf-generic.c b/drivers/pinctrl/pinconf-generic.c
new file mode 100644
index 0000000..33fbaea
--- /dev/null
+++ b/drivers/pinctrl/pinconf-generic.c
@@ -0,0 +1,120 @@
+/*
+ * Core driver for the generic pin config portions of the pin control subsystem
+ *
+ * Copyright (C) 2011 ST-Ericsson SA
+ * Written on behalf of Linaro for ST-Ericsson
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define pr_fmt(fmt) "generic pinconfig core: " fmt
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include "core.h"
+#include "pinconf.h"
+
+#ifdef CONFIG_DEBUG_FS
+
+struct pin_config_item {
+	const enum pin_config_param param;
+	const char * const display;
+	const char * const format;
+};
+
+#define PCONFDUMP(a, b, c) { .param = a, .display = b, .format = c }
+
+struct pin_config_item conf_items[] = {
+	PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL),
+	PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL),
+	PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL),
+	PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL),
+	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL),
+	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL),
+	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL),
+	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL),
+	PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "time units"),
+	PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector"),
+	PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode"),
+};
+
+void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
+			      struct seq_file *s, unsigned pin)
+{
+	const struct pinconf_ops *ops = pctldev->desc->confops;
+	int i;
+
+	if (!ops->is_generic)
+		return;
+
+	for(i = 0; i < ARRAY_SIZE(conf_items); i++) {
+		unsigned long config;
+		int ret;
+
+		/* We want to check out this parameter */
+		config = pinconf_to_config_packed(conf_items[i].param, 0);
+		ret = pin_config_get_for_pin(pctldev, pin, &config);
+		/* These are legal errors */
+		if (ret == -EINVAL || ret == -ENOTSUPP)
+			continue;
+		if (ret) {
+			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
+			continue;
+		}
+		/* Space between multiple configs */
+		seq_puts(s, " ");
+		seq_puts(s, conf_items[i].display);
+		/* Print unit if available */
+		if (conf_items[i].format &&
+		    pinconf_to_config_argument(config) != 0)
+			seq_printf(s, " (%u %s)",
+				   pinconf_to_config_argument(config),
+				   conf_items[i].format);
+	}
+}
+
+void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
+			      struct seq_file *s, const char *gname)
+{
+	const struct pinconf_ops *ops = pctldev->desc->confops;
+	int i;
+
+	if (!ops->is_generic)
+		return;
+
+	for(i = 0; i < ARRAY_SIZE(conf_items); i++) {
+		unsigned long config;
+		int ret;
+
+		/* We want to check out this parameter */
+		config = pinconf_to_config_packed(conf_items[i].param, 0);
+		ret = pin_config_group_get(dev_name(pctldev->dev), gname,
+					   &config);
+		/* These are legal errors */
+		if (ret == -EINVAL || ret == -ENOTSUPP)
+			continue;
+		if (ret) {
+			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
+			continue;
+		}
+		/* Space between multiple configs */
+		seq_puts(s, " ");
+		seq_puts(s, conf_items[i].display);
+		/* Print unit if available */
+		if (conf_items[i].format && config != 0)
+			seq_printf(s, " (%u %s)",
+				   pinconf_to_config_argument(config),
+				   conf_items[i].format);
+	}
+}
+
+#endif
diff --git a/drivers/pinctrl/pinconf.c b/drivers/pinctrl/pinconf.c
index b40ac1b..7321e86 100644
--- a/drivers/pinctrl/pinconf.c
+++ b/drivers/pinctrl/pinconf.c
@@ -54,7 +54,7 @@ int pinconf_validate_map(struct pinctrl_map const *map, int i)
 	return 0;
 }
 
-static int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
+int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
 			   unsigned long *config)
 {
 	const struct pinconf_ops *ops = pctldev->desc->confops;
@@ -439,6 +439,8 @@ static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
 {
 	const struct pinconf_ops *ops = pctldev->desc->confops;
 
+	/* no-op when not using generic pin config */
+	pinconf_generic_dump_pin(pctldev, s, pin);
 	if (ops && ops->pin_config_dbg_show)
 		ops->pin_config_dbg_show(pctldev, s, pin);
 }
@@ -482,6 +484,8 @@ static void pinconf_dump_group(struct pinctrl_dev *pctldev,
 {
 	const struct pinconf_ops *ops = pctldev->desc->confops;
 
+	/* no-op when not using generic pin config */
+	pinconf_generic_dump_group(pctldev, s, gname);
 	if (ops && ops->pin_config_group_dbg_show)
 		ops->pin_config_group_dbg_show(pctldev, s, selector);
 }
diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
index 0ded227..54510de 100644
--- a/drivers/pinctrl/pinconf.h
+++ b/drivers/pinctrl/pinconf.h
@@ -14,20 +14,26 @@
 #ifdef CONFIG_PINCONF
 
 int pinconf_check_ops(struct pinctrl_dev *pctldev);
-
 int pinconf_validate_map(struct pinctrl_map const *map, int i);
-
 int pinconf_map_to_setting(struct pinctrl_map const *map,
 			  struct pinctrl_setting *setting);
 void pinconf_free_setting(struct pinctrl_setting const *setting);
 int pinconf_apply_setting(struct pinctrl_setting const *setting);
-
 void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map);
 void pinconf_show_setting(struct seq_file *s,
 			  struct pinctrl_setting const *setting);
 void pinconf_init_device_debugfs(struct dentry *devroot,
 				 struct pinctrl_dev *pctldev);
 
+/*
+ * You will only be interested in these if you're using PINCONF
+ * so don't supply any stubs for these.
+ */
+int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
+			   unsigned long *config);
+int pin_config_group_get(const char *dev_name, const char *pin_group,
+			 unsigned long *config);
+
 #else
 
 static inline int pinconf_check_ops(struct pinctrl_dev *pctldev)
@@ -71,3 +77,34 @@ static inline void pinconf_init_device_debugfs(struct dentry *devroot,
 }
 
 #endif
+
+/*
+ * The following functions are available if the driver uses the generic
+ * pin config.
+ */
+
+#ifdef CONFIG_GENERIC_PINCONF
+
+void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
+			      struct seq_file *s, unsigned pin);
+
+void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
+			      struct seq_file *s, const char *gname);
+
+#else
+
+static inline void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
+					    struct seq_file *s,
+					    unsigned pin)
+{
+	return;
+}
+
+static inline void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
+					      struct seq_file *s,
+					      const char *gname)
+{
+	return;
+}
+
+#endif