pinctrl: pinconf-generic: Allow driver to specify DT params

Additionally to the generic DT parameters, allow drivers to provide
driver-specific DT parameters to be used with the generic parser
infrastructure.

To achieve this 'struct pinctrl_desc' is extended to pass custom pinconf
option to the core. In order to pass this kind of information, the
related data structures - 'struct pinconf_generic_dt_params',
'pin_config_item' - are moved from pinconf internals to the
pinconf-generic header.

Additionally pinconfg-generic is refactored to not only iterate over the
generic pinconf parameters but also take the parameters into account
that are provided through the driver's 'struct pinctrl_desc'.
In particular 'pinconf_generic_parse_dt_config()' and
'pinconf_generic_dump' helpers are split into two parts each. In order
to have a more generic helper that can be used to process the generic
parameters as well as the driver-specific ones.

v2:
 - fix typo
 - add missing documentation for @conf_items member in struct
 - rebase to pinctrl/devel: conflict in abx500
 - rename _pinconf_generic_dump() to pinconf_generic_dump_one()
 - removed '_' from _parse_dt_cfg()
 - removed BUG_ONs, error condition is handled in if statements
 - removed pinconf_generic_dump_group() & pinconf_generic_dump_pin
   helpers
   - fixed up corresponding call sites
   - renamed pinconf_generic_dump() to pinconf_generic_dump_pins()
   - added kernel-doc to pinconf_generic_dump_pins()
 - add kernel-doc
 - more verbose commit message

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 100 insertions, 82 deletions

diff --git a/drivers/pinctrl/pinconf-generic.c b/drivers/pinctrl/pinconf-generic.c
index 21b3d90ebb2d..e0886665b70a 100644
--- a/drivers/pinctrl/pinconf-generic.c
+++ b/drivers/pinctrl/pinconf-generic.c
@@ -27,17 +27,6 @@
 #include "pinctrl-utils.h"
 
 #ifdef CONFIG_DEBUG_FS
-
-struct pin_config_item {
-        const enum pin_config_param param;
-        const char * const display;
-        const char * const format;
-        bool has_arg;
-};
-
-#define PCONFDUMP(a, b, c, d) { .param = a, .display = b, .format = c, \
-                                .has_arg = d }
-
 static const struct pin_config_item conf_items[] = {
         PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
         PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
@@ -60,22 +49,25 @@ static const struct pin_config_item conf_items[] = {
         PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),
 };
 
-void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
-                              struct seq_file *s, unsigned pin)
+static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
+                                     struct seq_file *s, const char *gname,
+                                     unsigned pin,
+                                     const struct pin_config_item *items,
+                                     int nitems)
 {
-        const struct pinconf_ops *ops = pctldev->desc->confops;
         int i;
 
-        if (!ops->is_generic)
-                return;
-
-        for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
+        for (i = 0; i < nitems; 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);
+                config = pinconf_to_config_packed(items[i].param, 0);
+                if (gname)
+                        ret = pin_config_group_get(dev_name(pctldev->dev),
+                                                   gname, &config);
+                else
+                        ret = pin_config_get_for_pin(pctldev, pin, &config);
                 /* These are legal errors */
                 if (ret == -EINVAL || ret == -ENOTSUPP)
                         continue;
@@ -85,56 +77,46 @@ void pinconf_generic_dump_pin(struct pinctrl_dev *pctldev,
                 }
                 /* Space between multiple configs */
                 seq_puts(s, " ");
-                seq_puts(s, conf_items[i].display);
+                seq_puts(s, items[i].display);
                 /* Print unit if available */
-                if (conf_items[i].has_arg) {
+                if (items[i].has_arg) {
                         seq_printf(s, " (%u",
                                    pinconf_to_config_argument(config));
-                        if (conf_items[i].format)
-                                seq_printf(s, " %s)", conf_items[i].format);
+                        if (items[i].format)
+                                seq_printf(s, " %s)", items[i].format);
                         else
                                 seq_puts(s, ")");
                 }
         }
 }
 
-void pinconf_generic_dump_group(struct pinctrl_dev *pctldev,
-                              struct seq_file *s, const char *gname)
+/**
+ * pinconf_generic_dump_pins - Print information about pin or group of pins
+ * @pctldev:    Pincontrol device
+ * @s:          File to print to
+ * @gname:      Group name specifying pins
+ * @pin:        Pin number specyfying pin
+ *
+ * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
+ * specified either by pin using @pin or by group using @gname. Only one needs
+ * to be specified the other can be NULL/0.
+ */
+void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
+                               const char *gname, 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_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].has_arg) {
-                        seq_printf(s, " (%u",
-                                   pinconf_to_config_argument(config));
-                        if (conf_items[i].format)
-                                seq_printf(s, " %s)", conf_items[i].format);
-                        else
-                                seq_puts(s, ")");
-                }
-        }
+        /* generic parameters */
+        pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
+                                 ARRAY_SIZE(conf_items));
+        /* driver-specific parameters */
+        if (pctldev->desc->num_dt_params && pctldev->desc->conf_items)
+                pinconf_generic_dump_one(pctldev, s, gname, pin,
+                                         pctldev->desc->conf_items,
+                                         pctldev->desc->num_dt_params);
 }
 
 void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
@@ -148,17 +130,21 @@ void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
                 seq_printf(s, "%s: 0x%x", conf_items[i].display,
                            pinconf_to_config_argument(config));
         }
+
+        if (!pctldev->desc->num_dt_params || !pctldev->desc->conf_items)
+                return;
+
+        for (i = 0; i < pctldev->desc->num_dt_params; i++) {
+                if (pinconf_to_config_param(config) != pctldev->desc->conf_items[i].param)
+                        continue;
+                seq_printf(s, "%s: 0x%x", pctldev->desc->conf_items[i].display,
+                           pinconf_to_config_argument(config));
+        }
 }
 EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 #endif
 
 #ifdef CONFIG_OF
-struct pinconf_generic_dt_params {
-        const char * const property;
-        enum pin_config_param param;
-        u32 default_value;
-};
-
 static const struct pinconf_generic_dt_params dt_params[] = {
         { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
         { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
@@ -184,6 +170,47 @@ static const struct pinconf_generic_dt_params dt_params[] = {
 };
 
 /**
+ * parse_dt_cfg - Parse DT pinconf parameters
+ * @np: DT node
+ * @params:     Array of describing DT parameters
+ * @count:      Number of entries in @params
+ * @cfg:        Array of parsed config options
+ * @ncfg:       Number of entries in @cfg
+ *
+ * Parse the config options described in @params from @np and puts the result
+ * in @cfg. @cfg does not need to be empty, entries are added beggining at
+ * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
+ * needs to have enough memory allocated to hold all possible entries.
+ */
+static void parse_dt_cfg(struct device_node *np,
+                         const struct pinconf_generic_dt_params *params,
+                         unsigned int count, unsigned long *cfg,
+                         unsigned int *ncfg)
+{
+        int i;
+
+        for (i = 0; i < count; i++) {
+                u32 val;
+                int ret;
+                const struct pinconf_generic_dt_params *par = &params[i];
+
+                ret = of_property_read_u32(np, par->property, &val);
+
+                /* property not found */
+                if (ret == -EINVAL)
+                        continue;
+
+                /* use default value, when no value is specified */
+                if (ret)
+                        val = par->default_value;
+
+                pr_debug("found %s with value %u\n", par->property, val);
+                cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
+                (*ncfg)++;
+        }
+}
+
+/**
  * pinconf_generic_parse_dt_config()
  * parse the config properties into generic pinconfig values.
  * @np: node containing the pinconfig properties
@@ -191,39 +218,29 @@ static const struct pinconf_generic_dt_params dt_params[] = {
  * @nconfigs: umber of configurations
  */
 int pinconf_generic_parse_dt_config(struct device_node *np,
+                                    struct pinctrl_dev *pctldev,
                                     unsigned long **configs,
                                     unsigned int *nconfigs)
 {
         unsigned long *cfg;
-        unsigned int ncfg = 0;
+        unsigned int max_cfg, ncfg = 0;
         int ret;
-        int i;
-        u32 val;
 
         if (!np)
                 return -EINVAL;
 
         /* allocate a temporary array big enough to hold one of each option */
-        cfg = kzalloc(sizeof(*cfg) * ARRAY_SIZE(dt_params), GFP_KERNEL);
+        max_cfg = ARRAY_SIZE(dt_params);
+        if (pctldev)
+                max_cfg += pctldev->desc->num_dt_params;
+        cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
         if (!cfg)
                 return -ENOMEM;
 
-        for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
-                const struct pinconf_generic_dt_params *par = &dt_params[i];
-                ret = of_property_read_u32(np, par->property, &val);
-
-                /* property not found */
-                if (ret == -EINVAL)
-                        continue;
-
-                /* use default value, when no value is specified */
-                if (ret)
-                        val = par->default_value;
-
-                pr_debug("found %s with value %u\n", par->property, val);
-                cfg[ncfg] = pinconf_to_config_packed(par->param, val);
-                ncfg++;
-        }
+        parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
+        if (pctldev && pctldev->desc->num_dt_params && pctldev->desc->params)
+                parse_dt_cfg(np, pctldev->desc->params,
+                              pctldev->desc->num_dt_params, cfg, &ncfg);
 
         ret = 0;
 
@@ -274,7 +291,8 @@ int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
                 function = NULL;
         }
 
-        ret = pinconf_generic_parse_dt_config(np, &configs, &num_configs);
+        ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
+                                              &num_configs);
         if (ret < 0) {
                 dev_err(dev, "could not parse node property\n");
                 return ret;